Loading...
HomeMy WebLinkAboutEIA 02-04; COMMUNITY FOREST MANAGEMENT PLAN; FORESTRY MANAGEMENT; 2022-04-01Before urbanization, the landscape in and around Carlsbad was dominated by coastal sage scrub. The area is not inclusive of naturally occurring, large forested expanses. The average rainfall in Carlsbad would support only a handful of native tree species that have adapted to the local climate such as coast live oak, California sycamore, Mexican elderberry, and willow trees. These trees occur individually and in small groves, mainly limited to streamside and drainage locations. However, coastal Southern California's mild climate can support a large number of tree species when consistent supplemental water is made available. Because supplemental water is available through advanced irrigation systems, trees have been planted in Carlsbad that originate from many countries throughout the world. Native California trees play a minor role within the developed areas of the City, but still occur in many open space areas where, in spite of encroaching invasive species, they continue to survive. Despite the fact that Carlsbad's community forest is largely absent of native trees, as is the case with many southern California cities, the Urban Forest is an integral part of the City that must be maintained even more intensively, perhaps, than many other City assets. Shrubs, turf, sidewalks, streets, structures, utilities, and natural areas all affect or are affected by trees (Irvine Public Works 1991). In addition, wildlife such as birds, small mammals, and insects, all utilize the community forest. Delineating where the community forest begins and ends can be very difficult, especially in sprawling cites that are often separated from neighboring cities by only a demarcation on a map. The trees in neighboring communities can have an impact on City trees. For example, disease or insect problems can spread rapidly from city to city. These problems can be exacerbated if inadequate maintenance is applied to trees in neighboring communities (Irvine Public Works 1991). Within Carlsbad, citizens or associations manage the majority of trees in the community forest. City-managed trees exist in and around large pockets of mismanaged trees with high susceptibility for the spread of insect pests and diseases. As such, it is an important goal of this CFMP to define a successful program for educating citizens about caring properly for the many trees that are under their care. This Community Forest Management Plan is applicable to trees throughout Carlsbad, both private and public, but addresses specifically those portions of the community forest that the City can influence directly, that is the trees within the Street Tree Assessment District public rights-of-way (STAD). For the purpose of this plan, community forest refers to City-managed landscapes and open spaces within the STAD (Figure 2, page 4). Purpose of Community Forest Management As suggested, perhaps the most important consideration in community forest management is people. Community forests are created, managed, and sustained by people. Those same people help make decisions regarding tree removal, tree retention, tree replacement, and tree maintenance. People can affect the landscape by imposing landscape-changing impacts in the community forest that are comparable to natural disasters in a wild land forest. Like natural disasters, some of these have positive affects, while others are primarily negative. Educating people to make decisions regarding the community forest, or trees in their own yard, based on sound and reliable information results in a healthier and safer urban forest with more positive human impacts than negative. CARLSBADCOMMUNITYFORESTMANAGEMENTPLAN APRIL 2002 PAGE3 Car1sbad's Community Forest-Current Status Determining the current health, condition, species diversity, age, and size status of the community forest is critical to establishing appropriate management strategies. The City does not possess an up to date tree inventory. However, information collected in 1993 and recent estimates reveal that Carlsbad's urban forest within the public rights-of-way includes over 10,500 trees and 3,300 planting spaces. Among the 10,500 trees are 11 O genera represented by 195 species. The most common genus is Pinus (pine), comprising approximately 17 percent of the forest. This genus is followed by Eucalyptus (gum) (14 percent), Washingtonia (palms) (6 percent), Schinus (pepper) (5 percent) and Cupaniopsis (carrotwood) (4.2 percent). The remaining 105 genus' account for 53.8 percent of the population. No single species represents more than 4 percent of the population (Urban Forestry Consultants 1993). Both the genus and species population percentages throughout the City are in line with widely accepted standards that no single species represent more than 5-to 10-percent of a tree population and no genus more than 30 percent. This population distribution is discussed in more detail in Chapter 6. The portions of Carlsbad's community forest outside the ST AD (private trees in residential and commercial areas) include many more trees than the STAD areas, with estimates to 75,000 trees. Because there is no information specific to areas outside the STAD, the net tree species diversity throughout the City is unknown. However, it is believed that diversity throughout the City may vary from street to street or block to block, but that healthy diversity is maintained on the City-scale. The STAD trees and tree planting sites are managed by the General Services Department of the Public Works Major Service Area (MSA). Other community forest trees are managed by private citizens, homeowner associations, or property managers. The City of Carlsbad Community Forest includes valuable urban tree resources that provide a variety of environmental, aesthetic, and economic benefits to the community. A large percentage of the forest appears to be in overall good condition, with nearly 90 percent of the street trees rated in this category (Urban Forestry Consultants 1993). This is a testament to the tree maintenance practices of the City and the value placed on City-managed trees. Street Tree Policy Committee Despite the apparent overall good condition of Carlsbad's street trees, members of the public have voiced concern over removal and maintenance practices. Public concern is a common response in most cities to occasional removal of large, old trees or new tree planting. In response to the public testimony, the City proactively formed a citizen's committee to address tree removal and tree care within the community forest it manages. The Committee, appropriately named the Street Tree Policy Committee (STPC), formed in November 1999. Over a two-month period, the STPC met to discuss and develop a mission statement, goals, a purpose statement, and a comprehensive Street Tree Policy. The STPC's Final Report (January 25, 2000) is available in its entirety at all City Library branches and by request to the City General Services Department. The City's Municipal code regarding trees in the public right-of-way is viewable at WWW.bpcnet.com/codes/car1sbad, Title 12 -Trees and Shrubs. In summary, the STPC's Final Report addresses the need to update the City's 30-year old street tree policy. In so doing, the STPC acknowledged the many benefits of urban trees to those that live amongst them and the importance of sound tree and community forest CARLSBADCOMMUNITYFORESTMANAGEMENTPLAN APRIL 2002 PAGE S management. The report includes a Statement of Policy that directs management of tree planting, removal, replacement, and maintenance, as well as heritage trees, and public appeals. The purpose of the Statements of Policy is to improve the condition of the urban forest and streamline management of its resources and the issues that are commonly associated with street trees. One of the first tasks accomplished by the STPC was developing a Mission Statement. The STPC's Mission Statement reads: "To develop a recommendation to the City Council, which provides for the conservation, enhancement and management of street trees within the public rights--of- way in the area west of El Camino Real to the Ocean, between Agua Hedionda and Buena Vista Lagoons." As evidenced in the Mission Statement, the recommendations of the STPC focus on improving the condition of the urban forest by conservation (the most efficient use, preservation and management of tree resources) and enhancement, through proper care and maintenance. Accomplishment of the mission requires a management strategy. As such, among the recommendations strongly supported by the STPC was the creation of a Community Forest Management Plan (CFMP) for the City of Carlsbad. To that effect, a professional natural resources and urban forestry consulting firm was retained by the City to prepare a CFMP. Shortly thereafter, a CFMP planning team was organized and included several City staff, Carlsbad's Parks and Recreation Commission, an STPC member, the consultant, and several one-meeting participants (Table 1 ). The planning team met four times over a period of approximately three months. The meetings centered on developing an outline for the CFMP that incorporated policies previously created by the STPC. The meetings were also conducted to provide background information regarding the City's current urban and community forest, its history and current and proposed policies, all of which would be enhanced and incorporated into the CFMP. Table 1 Members of the CFMP PlanninQ Team Name Title Association DouQ Duncanson Public Works Manaaer Citv of Carlsbad Scott Carroll ManaQement Analvst City of Carlsbad Fred Burnell Public Works Supervisor -Trees and City of Carlsbad Medians Garv Cox Commissioner Parks and Recreation Commission Seth Schulbera Commissioner Parks and Recreation Commission Anthonv Lawson Vice Chairman Street Tree Committee AOL Plannina Associates Mike Huff Sr. Proiect Manaaer/Arborist Integrated Urban Forestry One-meetina Particioants Karl Von Schlieder GIS Coordinator Citv of Carlsbad Geoff Armour Historical Preservation Committee City of Carlsbad Martin Aauillera Deoutv Fire Marshal Citv of Carlsbad Fire Department Bill Clavton Wild land Hazard Officer City of Carlsbad Fire De=rtment Mike Smith Division Chief/Fire Marshal Citv of Carlsbad Fire Deoartment This CFMP is based on recommendations offered by the STPC and provides management strategies to successfully implement the STPC Statements of Policy. The management components of this CFMP are applicable to all trees within the City of Carlsbad. However, due to political boundaries, it is enforceable only in those areas within the STAD. CARLSBAD COMMUNITY FOREST MANAGEMENT PLAN APRIL2002 PAGE6 • reduction of erosion • wastewater cleansing • wildlife habitat for birds, mammals, reptiles, amphibians, and insects • reduction of carbon dioxide and particulate pollutants • higher property values Trees add tremendous value to a community, both intrinsic and perceived. The City of Carlsbad realizes the benefits trees offer. This CFMP was initiated by the City to help guide the management of the community forest in order to maximize tree benefits. The following Chapters of this CFMP address specific components of Carlsbad's Community Forest. Each chapter provides definitions of the City's policies and recommendations for improving the health and sustainability of Carlsbad's Community Forest. CARLSBAD COMMUNITY FOREST MANAGEMENT PLAN APRIL2002 PAGE9 Chapter 3 -Uniform Street Tree Planting Map "Decision-making is much easier when tree .. .information is graphically available." The Uniform Street Tree Planting Map (USTPM) includes approximated locations of trees within the STAD. A copy of the USTPM is available at the office of the Parks Division of Public Works, due to its volume, it is not included in this CFMP. Also included on the USTPM are locations of valid tree planting sites. The City maintains a database of its trees that includes species, size, address, and other attribute information. This tree information was last collected in 1993 and is therefore becoming less useful with time. Many trees have been removed, planted, or have changed in size or condition since the original inventory. The City must update this database by conducting a street tree inventory within the next two years, as most tree information within the database is currently over eight years old. The recommended inventory will provide the means with which to make the link between the digital tree locations and updated attribute information. The importance of establishing this link is paramount. With this link in place, trees can be visually presented in a geographical information system (GIS) at their precise location and for any attribute they posses. For example, guidelines for species distribution, size, height, and condition, amongst others, can be querried and the resulting information graphically presented in a city base map. Decision- making is much easier when tree attribute distribution information is graphically available. The USTPM displays the locations of City-owned trees within the ST AD and the vacant tree spaces that should be planted to meet maximum stocking goals. Tree locations are generally located, to the parcel scale and were generated by the City's GIS department. They are not precise tree locations and groupings of tree types have been completed in an effort to simplify graphical presentations. Following a complete inventory, the data will be easily manipulated by City GIS operators who will be able to provide high quality, accurate maps that display attribute information such as those presented in Table 2. Table 2. Uniform Street Tree Plantina Mao ootential caoabilities* Function Output Advantages Query trees by species Map depicting species distribution Easily determine where species are occurring, allows throughout the Assessment creating Of enhancing species diversity, or unifying District (STAD) neighborhoods with similar species, aids species selection for reforestation. Query trees by planting Map depicting small, medium, and Easily determine what size tree from the approved space large planting sites throughout the street tree species list should go in which planting STAD spaces before field crews begin work. Query trees by condition Map depicting trees by overall Allows managers to focus attention on trees that may condition present higher hazard potential. Query trees by user-Map depicting trees by user-Allows managers to proactively monitOf and manage defined criteria defined criteria the City's trees to reduce conflict, prevent damage, obtain maximum benefits. *Capabilities refer to future capabilities following a tree inventory CARLSBAD COMMUNITY FOREST MANAGEMENT PLAN APRIL2002 PAGE14 Tree Distribution Tree species are distributed throughout the City STAD to varying levels of uniformity and diversity. The 1993 information based USTPM reveals a great deal of variation amongst neighborhoods, along streets, and in sections of the City. Some areas, such as along Jefferson Street, between its intersection with Buena Vista and Las Flores Drive, displays rich species diversity with ten different species intermixed in the parkways. Other areas include large numbers of one species, such as Italian cypress along Carlsbad Village Drive, or the magnolias along Highland Drive, with no or few additional species. These areas are intentionally planted to only a few species to present a unifying theme for a particular neighborhood. Themes are supported by the City as long as diversity is maintained on a larger scale. As such, the following section discusses tree-planting themes. Tree Themes Tree themes are evident throughout the City, although many of them are becoming less and less pure as old age has caused vacancies that have been filled with non-conforming species. Monroe Street includes one such theme. Four different species are planted along Monroe, and they are all of the genus Eucalyptus. Eucalyptus are a precarious species due to the many insect pests that attack them and often times cause their loss. Maintenance of the theme along Monroe can be accomplished with the addition of certain eucalyptus species and species resembling eucalyptus such as Sydney blue gum or Brisbane box in appropriately sized planting spaces. Basswood Avenue between its intersection with Valley Street and Monroe Street includes three different palm species. The consistency of the palms provides a unifying theme. The diversity introduced by the varying species of palms also provides some protection from catastrophic tree mortality associated with insects or disease specific to a particular palm species. A similar theme street is along Pine Avenue. The six species that are present on this street are all large, spreading trees with Canarly island, Torrey, and allepo pines intermingled with sugar and blue gums, and sycamore. As declining condition or mortality requires that trees are removed, the City may decide to replant various pine trees only on Pine Street for consistency and theme purposes. Themes should continue throughout the City's neighborhoods and streets. However, there are many ways to provide themes, some of which have been discussed herein. Single species tree planting is not recommended on a large scale when themes can be perpetuated in more ecologically smart ways. Vacant Planting Spaces There are a large number of vacancies throughout the City STAD. The areas with the most prominent vacancies include: • Carlsbad Village Drive between Monroe and Concord Streets • Sevilla Way between Valencia and Cordoba! Place • Jefferson Street between Magnolia and Tamarack Avenues • Camino Del Prado CARLSBADCOMMUN/7YFORESTMANAGEMENTPLAN APRJL2002 PAGE15 • Linda Lane • Lee Court Areas including large percentages of vacant sites (according to 1993 data) will be the focus of planting efforts over the next several years. Arbor Day celebrations, grant matching funds, and other special projects should concentrate on planting the vacancies to help achieve the City's full stocking goals. All tree plantings should be from the approved species list and should be appropriate for the available space. CARLSBADCOMMUNTTYFORESTMANAGEMENTPLAN APRIL 2002 PAGE16 is expected to increase with planting of the more than 3,000 vacant tree spaces. Reevaluation of the urban forest as part of an updated tree inventory will provide more insight into the size/age distribution of the City's trees. Once this is complete, management actions can focus on developing an urban forest that more closely matches the recommended size/age distribution which will help ensure sustainability of the Community Forest. Tree Removal Policy The City follows a standard protocol when trees must be removed and replacement is scheduled. In summary, a letter is submitted to residents in the vicinity of trees scheduled for removal one month prior to action. The letter notifies residents that a tree will be removed and whether the tree will be replaced, and if so, what tree species has been selected for replacement planting. Residents have one month to appeal. Once the tree has been planted, there is no appeal. The City's street tree removal and replacement appeal process is clearly defined and consists of the following: • Residents must respond within 30 days of notification or appeal is no longer possible. • Residents must submit an appeal form with the $120 appeal fee. • Hazard trees are removed immediately with no appeal process. • Parks and Recreation Commission determines the action of an appeal. • The species replacement will be from the new list and staff recommendation. Old age trees are typically the large, dominant trees in the community forest that residents become emotionally attached to for many different reasons. Large trees provide many benefits and are often a link to days gone by. They do, however, become significant hazards in an urban environment and will all eventually require removal. The City follows consistent criteria for removal and replacement of its large and old trees. Every effort is made to retain these valuable resources, but not at the expense of public safety and community forest health. CARLSBADCOMMUNfTYFORESTMANAGEMENTPLAN APRIL 2002 PAGE20 (avoid monocultures). These guidelines can provide general direction when tree-planting decisions are made. This does not mean that small areas, neighborhoods, for example, should only be planted with many different species. Tree species diversity on the city-scale is the goal. Neighborhoods may be planted with as few as one or two species for unifying purposes. It would be wise to plant more than one species in these areas, but on such small scale, the potential for impacting the City-scale diversity is low. The forest outside the ST AD currently is very diverse and offers great potential for offsetting large-scale tree mortality from species specific infestations or infections at the street level. City Approved Replacement Tree Species List To minimize long-term costs and maximize tree-provided benefits, the right tree must be planted at each designated planting site. Proper species selection should equate to a diversified mix of species. This means that planning for the best species for a given site must include ecosystem-level planning to avoid mono-culture-effects on the landscape {Thompson, et. al. 1994 ). The principles most utilized in urban forest design for achievement of sustainability are: 1) size/age class distribution 2) size/age class and species richness 3) management practices to maintain forest health and growth In order to provide a measure of containment and management, a list of suitable trees for varying sites has been prepared. Table 4, page 24 -25 presents this list of trees that are appropriate for urban settings within the City and that have been authorized as the tree replacement species list for all tree replacements and new plantings within the ST AD. The trees are separated into small, medium, and large planting sites. A small planting site would be any planting site that measures no larger than 3' x 3', medium planting sites measure no larger than 6' x 6', and a large planting site includes all planting sites over 6' x 6'. This list is the approved tree replacement list for the City. It must be noted that these trees may not be recommended for every planting site in a particular size range. Each planting site offers a number of positive and negative attributes that may or may not be appropriate for a given species. Soils, exposure, aspect, and other micro-environmental factors must be considered when selecting a tree for a particular space. In general, however, the trees in each category meet size requirements and limitations for expected planting space sizes. Representative visual samples of each of the 29 tree species from the approved list are provided in the photograph log in Appendix B. The trees included in the approved City planting list generally perform well in coastal settings, are readily available from local nurseries, are relatively low maintenance, provide typical benefits of shade trees, include both deciduous and evergreen trees, and are known for minimal root infrastructure problems. Some of these trees are also approved for planting in confined planting spaces where structures or utility related apparatus may limit growth. Limiting plantings within the ST AD to the 29 species included in the approved planting list will enable the City to maintain diversity on the community and City level while still allowing unifying tree planting themes at the street-level. It also results in a healthier design for the CARLSBAD COMMUNITY FOREST MANAGEMENT PLAN APRJL2002 PAGE23 forest, by limiting the number of ill-advised plantings that would not contribute positively to the Community Forest. Table 4. City Approved Replacement Tree List. Botanical Name Common Height Spread Growth Longevity Pest Irrigation Name Rate Disease Needs Large Planting Site Candidate Trees (Larger than 6' x 6') Cinnamomum Camphor tree 40-60 50-70 Moderate Long Lived Mid Level Moderate camphora Eucalyptus citriodora Lemon gum 60-80 20-40 Fast Moderate Mid Level Low E. saligna Sydney blue gum 150 50 Fast Moderate Low Moderate Magnolia grandif/ora So. magnolia 50-70 30-40 Moderate Long Lived Mid Level Moderate Pinus canariensis Canary Island 60-90 30-40 Fast Long Lived Low Level Low pine Podocarpus gracilior Fem pine 50-60 50-60 Slow Long Lived Mid Level Moderate Querr:;us agrifolia Coast live oak 50-60 50-60 Moderate Long Lived High Low Umbellularia California laurel 40-60 40-60 Slow Long Lived Low Level Moderate califomica Medium Planting Site Candidate Trees (3' x3' to 6' x 6? Archontophoenix King palm 50-65 20 Moderate Moderate Low Level Low cunninghamiana Cassia leptophylla Gold medallion 20-30 20-30 Fast Moderate Mid Level Moderate tree Fraxinus oxycarpa Flame ash 30-40 25-35 Moderate Moderate High Moderate 'Raywood' Level Laurus nobilis Sweetbay 30-40 30-40 Moderate Moderate Low Level Low Lophostemon Brisbane box 30-45 20-25 Fast Moderate Low Level Moderate confertus Pistacia chinensis Chinese pistache 30-40 30-40 Moderate Moderate Low Level Moderate Melaleuca Cajeput tree 30-40 15-20 Moderate Moderate Low Level Moderate quinquenervia Pinus eldarica Afghan pine 40-50 40-50 Moderate Long Lived Mid Level Low CARLSBADCOMMUNfTYFORESTMANAGEMENTPLAN APRIL2002 PAGE24 Podocarpus Yew pine 35-40 10-15 Slow Long Lived Mid Level Moderate macrophy//us Quercusi/ex Holly oak 40-50 40-50 Moderate Moderate Mid Level Moderate Syagrus Queen palm 45-50 20 Moderate Moderate Low Level low romanzoffianum Small Planting Site Candidate Trees (Smaller than 3' x 3? Acer ob/ongum Evergreen maple 20-25 20-25 Moderate Moderate Low Level Moderate Agonis f/exuosa Peppermint tree 25-30 25-30 Fast Moderate Low Level Moderate Arbutus unedo Strawberry tree 10-30 10-30 Slow Moderate Low Level Low 'marina' Brahea annata Mexican blue 35 15-20 Moderate Moderate Low Low palm Brahea edulis Guadalupe palm 35 10-15 Moderate Moderate Low Low Callistemon citrinus Lemon 10-15 10-15 Moderate Short Lived Mid Level Low bottlebrush Eucalyptus ficifolia Red flowering 20-45 15-60 Moderate Moderate Low Level Moderate gum Lagerstroemia Crape myrtle 15-25 10-20 Moderate Moderate Mid Level Moderate hybrids Metrosideros New Zealand 15-30 15-30 Moderate Moderate Low Level Moderate excelsus christmas tree Prunus cerasifera Pu pie-leaf 15-25 15-25 Moderate Short Lived High Moderate Thundercloud' thundercloud Level Factors affecting tree species inclusion in the approved list include: tree fonn, size at maturity and at planting, height, canopy spread, height to canopy bottom, canopy density, trunk size, root habit, rate of growth, longevity, habitat requirements, irrigation needs, shade tolerance, insect and disease problems, wood strength, litter, texture, flowers, fruits, bark, objectionable features, and wildlife benefits. As tree populations approach the target maximum goals for the City-, community-, or street- level tree populations, reliance on that species should be reduced and other tree species should be planted. As such, this list of approved species must be flexible enough through time and adjustments made to react to the ever-changing needs of the urban forest. Pests, die-off, storm damage, and other events can drastically alter the tree population and necessitate drastic planting measures to regain appropriate and healthy species diversity. Reevaluation of the approved species list including adding and removing species, as necessary is a proactive means of maintaining healthy, diverse, community forest. CARLSBAD COMMUNfTY FOREST MANAGEMENT PLAN APRIL2002 PAGE25 As discussed in the previous chapter, it is recommended that tree planting in the ST AD consider unifying tree themes within neighborhoods and communities. Two to several tree species may be planted on a particular street. Current tree species distribution (1993 data) within the STAD is available in a graphical format through the City Parks Division of Public Works. It is also recommended that tree planting be conducted concurrently with every removal, where planting space allows. A successful tree planting program would include planting a tree for each removal and then also planting a percentage of the vacant spaces such that the vacant spaces will be planted within a given time frame, ten years, for example. CARLSBAD COMMUNITY FOREST MANAGEMENT PLAN APRIL2002 PAGE26 historical photos and newspaper articles to determine the final recommended list of heritage trees. A recommended management plan will also be developed based on current best management practices to be utilized in maintaining the City owned trees. The information should also be provided to the private property owners as a guide to assist them in managing their privately owned trees. The intent is to have healthy trees that can live successfully for many years before they need to be removed and replaced. When completed, this information will be provided to the City for review and adoption and incorporated in the CFMP. Recommendations will also be made on how additional heritage trees can be added to the list in the future. CARLSBADCOMMUNITYFORESTMANAGEMENTPLAN APRIL2002 PAGE28 Situation assessments Situation assessments require one of three City personnel. Typically, the supervisor or one of the tree trimming lead workers would assess the situation. Contact information is provided below: Public Works Supervisor -Trees and Medians Tree Trimming Lead Worker Private tree crew contact list (760) 434-2985 (760) 434-2983 The following Tree Service Contractors are listed as the City's preferred providers of tree maintenance: Henderson Tree Service of San Diego P.O. Box 15230 San Diego, California 92175 (619) 667-9341 -phone (619) 667-9389 -facsimile Funding for emergency tree work Sutton Tree Service 2236 S. Santa Fe Vista, California 92084 1-800 909-8733 -phone (760) 727-3813 -facsimile Funding for emergency tree removal, cleanup, pruning, and disposal would be provided from existing overtime maintenance budgets. In especially severe disasters where an area qualifies as a national disaster area, Federal Emergency Management Act (FEMA) funds would be appropriated. CARLSBADCOMMUNTTYFORESTMANAGEMENTPLAN APRIL2002 PAGE30 dead, referred to as "snags", and require removal. Removal of these trees and replacement with resistant species is critical for long-term sustainability oft he Grove. • Eucalyptus long-horned borers and other detrimental pathogens were observed throughout the Grove. They typically attack trees that are experiencing stress; reducing tree stress is, therefore, important for long-term vitality. There is a lack of adequate signage throughout the Grove. Expectations Natural and human caused pressure will continue to cause trees to be lost to insects and disease. Red and sugar gum trees, which together comprise 98-percent of the tree population, require 50-to 100-percent more water than they receive through annual rainfall in Carlsbad. Therefore, a combination of methods to increase the water supply in the root zone is needed, e.g. supplemental irrigation, breaking up compacted soils, and mulching. Planting drought tolerant species during the reforestation phases of this project will be critical to long term sustainability of this community Grove. • Adequate tree spacing, soil amendments, top-mulching, irrigation, and soil fertility will improve tree health. Introducing age and species diversity into the Grove will improve tree health and sustainability. Secured funding of nearly $60,000 per year will be nee essary to implement this Grove management plan. A part-or full-time staff person is required , along with associated equipment and vehicle, to provide planting, care, and maintenance to the Grove. Management Program This study was initiated to assess the eucalyptus trees that comprise the Hosp Grove Open Space in the City of Carlsbad (City) and to develop a management plan for both short-and long-term Grove improvements. This management plan is intended to serve as a framework for future planning and maintenance activities concerning the Grove. Although this study specifically addresses Hosp Grove, the maintenance guidelines may also be applicable to other eucalyptus plantings in the City. Woodbine Banks (located along El Camino Real between Tamarack Street and Chestnut Street), a 14-acre eucalyptus grove open space, is one such example. The City of Carlsbad Fire Department provides maintenance and clean- up to the Woodbine Banks area that includes access maintenance, tree trimming, and underbrush clearing. This Management Plan centers on improving Hosp Grove (Woodbine Banks and other similarly forested areas) through a sustainable management approach. A program that maximizes the use of available natural resources, introduces species and age diversity, reduces tree stress factors, and provides an increased level of care will reinvigorate trees in this area. This comprehensive plan provides guidelines to improve the short-and long-term viability of Hosp Grove. This management strategy requires large-scale tree removal and replacement along with long-term planning to achieve many of its goals. CARLSBAD COMMUNITY FOREST MANAGEMENT PLAN APRJL2002 PAGE34 Establishment of a natural grove, through specific management techniques, will encourage a less dense, more sustainable stand of trees with varied tree spacing and greater age and size diversity. Initially, a large number of dead trees must be removed. For some Grove areas, the resulting tree spacing will be suitable and will not require immediate tree planting. Remaining areas that do not include a large number of dead or dying trees will require tree removals to improve tree density and spacing. Where necessary, tree thinning is recommended and will include removal of some healthy, but suppressed trees in overcrowded areas. Wider tree spacing and soil mulch cover will encourage natural production of seedlings and saplings while understory plant establishment and growth can be discouraged. Specific objectives of this study are: To preserve and enhance Hosp Grove for future generations to enjoy as a visual, educational, research, and recreational amenity. • To implement Grove management techniques that will create a more diverse, healthy, and sustainable Grove. Methodology Methodology for determining optimum long-term management strategies for the Grove include: • A review of documents relating to the Hosp Grove and adjacent landscapes (see references cited at the end of this report) • Meetings with key people, departments and groups (noted in References Cited) • Discussions with other professionals (e.g. foresters and silviculturlists in Australia and the U.S. • An examination and sampling of Hosp Grove Although each of the phases of research, meetings, and discussions with other professionals is important to the success of a management program, the most important component of any forest management plan is arguably the site information gathering phase. One must have a tangible idea of the composition of a forest, including species, size, condition, and distribution in order to make sound management recommendations. To facilitate determination of the types and quantities of trees Hosp Grove includes, the Grove was sampled using a commonly practiced technique called "plot sampling". According to this method, the entire Grove is considered one large stand of trees. A stand is a continuous group of trees sufficiently uniform in species composition, age class arrangement, and health and structural conditions to be considered a homogeneous and distinguishable unit. According to this method, a desired sampling size (percentage of entire area) is predetermined in the office and sample plots are established on aerial photos or other maps of the Grove. In this study, a seven-percent sampling size was selected. Accordingly, fifty (50) plots, each measuring 1/10-acre in size were established in a random grid across the Grove. These plots were then located in the Grove during the field component of the survey, and all trees located within the plots were evaluated and recorded. Information was then processed and analyzed following fieldwork. The resulting information can be statistically extrapolated to provide a reasonably accurate representation of the Grove as a whole. CARLSBADCOMMUNITYFORESTMANAGEMENTPLAN APRIL2002 PAGE35 Conclusions As previously provided, and based on our findings and analysis, the following observations and expectations have become our framework for developing a multi- faceted, financially realistic, long-term management plan for the Hosp Grove. Observations Many of the Grove trees are 40 years old or older and are losing vigor. Because of the planting density, there are too few resources (such as available water, soil nutrients, and sunlight) to sustain the Grove in a healthy condition, especially in the presence of insect pathogens. In some areas of the Grove, competition between trees is intense. There is no supplemental irrigation available to the trees except to those that border adjacent residential development. There is a lack of adequate signage throughout the Grove. A well-developed trail system allows users access to many portions of the Grove. Off trail use is also prevalent. • In high to moderate traffic areas, high soil compaction is creating limited oxygen and water availability to the root zones. Red gum lerp psyll a have taken a large toll on the Grove. Thousands of trees are standing dead, referred to as "snags", and require removal. Removal of these trees and replacement with resistant species is critical for long-term sustainability of the Grove. • Eucalyptus long-horned borers and other detrimental pathogens were observed throughout the Grove. They typically attack trees that are experiencing stress; reducing tree stress is, therefore, important for long-term vitality. Expectations Natural and human caused pressure will continue to cause trees to be lost to insects and disease. Red and sugar gum trees, which together comprise 98-percent of the tree population, require 50-to 1 OD-percent more water than they receive through annual rainfall in Carlsbad. Therefore, a combination of methods to increase the water supply in the root zone is needed, e.g. supplemental irrigation, breaking up compacted soils, and mulching. Planting drought tolerant species during the reforestation phases of this project will be critical to long term sustainabi lity of this community Grove. Adequate tree spacing, soil amendments, top-mulching, irrigation, and soil fertility will improve tree health. Introducing age and species diversity into the Grove will improve tree health and sustainability. Funding of nearly $60,000 per year (staffing, tree planting, monitoring, maintenance) needs to be apportioned to implement this Grove management plan. A part-or full-time staff person is required, along with associated equipment and vehicle, to provide planting, care, and maintenance to the Grove. CARLSBAD COMMUNITY FOREST MANAGEMENT PLAN APRIL2002 PAGE42 Biomass (tree trunks, leaves, branches) from the removal trees should be used constructively throughout the Grove. Leaves, small branches, and smaller trunks can be chipped and applied as mulch or sold to companies that operate electric generating portable biomass power plants. Larger branches and tree trunks can be milled for lumber, used to delineate paths and boundaries, cut for firewood, or used for erosion control. The education program should also include information on how the removed dead and dying trees are being utilized. A practice of "zero-waste" should be adopted and communicated. After the initial thinning, trees should be selectively removed when they have declined to an unacceptable level, typically when they die or present hazard potential beyond a level considered acceptable by the City. Competition for resources wi II naturally result in the more vigorous trees growing to become dominant trees. When a particular area becomes unacceptably sparse, news eedlings may need to be occasionally planted. Depending on the size of the replanting area and degree of shade from existing healthy trees, some or all of the existing trees in the replant area may need to be removed. More drought tolerant, site appropriate eucalypts and other species can be planted to improve long-term sustainability and species diversity. Suggested species can be found in the Reforestation section. Irrigation will be necessary to establish trees and bring retained eucalyptus trees back to health. Once trees are established, the irrigation can slowly be decreased and phased out over a three-to five-year period. If irrigation is not supplied, the trees will continue to have a high degree of stress that will result in low establishment success and irregular growth patterns, shorter useful life span, and a faster decline in health and structural integrity. Irrigation may be necessary indefinitely to maintain some of the trees' health during drought periods and those on particularly dry, south or east facing slopes. Ultimately, trees species that are tolerant of Carlsbad's typical moisture regime will be established, decreasing the need for irrigation. According to this plan, the Grove will be managed to encourage a more natural woodland character, slowly replacing the planting grid throughout the Grove. Following removal of dead and dying trees, the remaining trees should be evaluated for distribution and spacing. Where needed, the mature trees should be selectively removed to develop a random pattern with a broader range of spacing (8-to 40-feet). Selective removal techniques are discussed in the fol lowing section. At this greater spacing, a more sustainable tree density will be achieved and the indi vidual trees comprising the Grove will be able to grow and develop a healthier and m ore attractive structure. Also with wider spacing, natural production of seedlings and saplings can be encouraged. Growth of undesirable species and potentially fire hazardous plants will require diligent monitoring and rem oval. The greater the spacing, the larger and healthier the trees will be. A less dense, and more sustainable stand of trees will eventually evolve with greater age and size diversity, but with similar overall Grove canopy cover. Selective Tree Removal Selective tree removal is the removal of individual trees based on certain criteria. For Hosp Grove, trees would be selected for removal based on the following criteria, in order of priority: CARLSBAD COMMUNITY FOREST MANAGEMENT PLAN APRIL2002 PAGE46 the anticipated per acre tree density would be approximately 50-to 60 trees per acre throughout the Grove after the fourth year. Tree planting would begin the first year and continue for fifteen consecutive years. By the end of the fifteenth year of planting trees, it is estimated that as many as 5000 trees may be planted. The resulting tree density would be approximately 75-to 120-trees per acre, a much more sustainable level than the 200 trees per acre currently on the site. As mentioned, tree removals would leave openings in the canopy cover. This allows enough sunlight into the reforestation area to support growth of the new trees. Larger openings may have negative impacts such as visual discontinuity and growth of fire prone or high volatility fuels. A mosaic of smaller openings in the Hosp Grove wi II create an uneven aged forest. The original Grove was largely even-aged, resulting in an entire population that can be devastated by pests, as is currently the case. Uneven aged forests or groves include an array of age classes. When the Grove is complete! y planted, the overstory will have many different canopy heights, which will not only include age, size, and species diversity, it will also aid in the creation of more niches for birds and other organisms. Uneven aged management is a concept used in traditional forestry. Planting replacement trees in small sizes, i.e., one-and five-gallon trees is recommended. The smaller trees typically surpass larger size stock in both size and vigor within a relatively short period. Anchorage development is also superior to that of fifteen-gallon and larger trees, which has a net positive effect on erosion control and tree failure. The generally accepted establishment period for the small container trees will be between three-and four- years for most species. Contract-grown, one-and five-gallon "deep-pot" container plants are recommended. On average, five-gallon trees will have a trunk caliper of½ inch and a height of three-to four-feet; one-gallon seedlings will have a¼ inch caliper and be two-feet tall. Trees grow more vigorously and adapt to soil conditions more rapidly when planted as small trees with healthy root systems. For natural forest re-creation, planting density should vary from 8 to 40 feet and for some species, such as oaks, multiple trees should be clustered together with clusters widely spaced. Replacement of non-surviving seedlings will be necessary. Refer to the tree selection, planting and staking specifications in Appendix C. The planting of this natural area should be completed according to accepted practices. Namely, the trees placed in the drainages should be planted in clusters of three to four seedlings, acorns, and container trees. Because these areas may be irrigated, 1-, and 5-, gallon trees could be planted along with acorns and seedlings. When planting acorns, seedlings, or container grown trees, the first step is to ensure that the planting location is suited to the tree being planted. Slope, aspect, proximity to stream courses, proximity to developments, shade, drainage, soil type, and presence of other healthy trees are all factors to be considered when choosing a planting location for these trees. The clusters should be spaced approximately 15-to 20-feet apart such that roughly 80 planting spots per acre are supported. In the open areas, the trees should also be planted in clusters of three to four seedlings, acorns, and container trees, but the spacing should be slightly less dense, about 30-to 40-feet between tree clusters. Note: Most of the Hosp Grove will require thinning to various degrees to open up the canopy and no or little immediate tree planting. Only some areas will require immediate replanting with new trees. CARLSBADCOMMUNfTYFORESTMANAGEMENTPLAN APRIL 2002 PAGE49 If at all possible the trees should be planted in late fall and winter in order to capture the benefits of natural rainfall and cooler temperatures. It will require more intensive maintenance to care for tree and shrubs planted during the spring and summer. Throughout the Grove, planting other pest resistantEuca/y ptus species and Brisbane box (Lophostemon confertus, formerly Tristania conferta) is desirable along with introduction of trees such as coast live oak ( Quercus agrifo/ia ), California sycamore (Platanus racemosa), California pepper (Schinus mo/le), and possibly Catalina ironwood (Lyonothamnus floribun dus). Some suggested Eucalyptus species that have a greater drought tolerance but are similar in character to the sugar gum and have shown resistance to pests include: • E. saligna -Sydney blue gum • E. leucoxylon -White-iron bark • E. polyanthemos -Silver Dollar Gum • E. sideroxyfon-Red-iron bark Normally, non-Eucalyptus species would not be planted within the Grove. However, to introduce species diversity and to avoid large-scale tree mortality, which the Grove is currently suffering, it is recommended that non-eucalyptus species be planted throughout Hosp Grove to augment the eucalyptus species. Photographs of trees recommended for inclusion in the Hosp Grove Planting Plan are presented in the Photograph Log in Appendix D. The allelopathic affects of Eucafypts (inhibition of growth in one species of plants by chemicals produced by another species) must be assessed prior to replacement tree selection. The first year removal/rep! acement area should be considered a test plot with several species included in the planting pallet. Success and failure of individual species must be monitored and tracked in order to select species that can withstand allelopathic affects, grow in the site's soils, and are suitable for the local microclimates. All newly planted trees will require supplemental irrigation until they are well established. The trees may require three years of light pruning to train and develop their basic framework. Trees will normally be planted with two to three stakes. These stakes should be checked annually to make sure neither the stake or tie are damaging the trees. All stakes should be removed as soon as the tree can stand upright on its own, usually one to two years is sufficient. Planting, care and maintenance of the Grove will require a part-or full-time person to monitor irrigation and tree establishment. To complete this job, equipment including a rugged vehicle will be necessary. This is discussed further in the Operation Plan - Chapter 10 of the Carlsbad Community Forest Management Plan. CARLSBADCOMMUNITYFORESTMANAGEMENTPLAN APRIL 2002 PAGE50 width; maintain a minimum twenty-(20) feet separation between shrub groupings. In Natural Groves with unmaintained under story, maintain at least a twenty-foot separation between tree canopy groups; three to six trees can constitute a group. This will reduce the spread offire from treetop to treetop and create a more random spacing varying from eight-to forty-feet. Reduce the height of un derstory plants and/or remove trees (or large shrubs) lowest limbs so that the lowest part of the trees' canopy is at least three times higher than the height of the vegetation below, or six-feet, whichever is higher. • Maintain the dirt/gravel trails, where practicable throughout the Grove in order to break-up a ground fire. The trail will need to be as wide as three times the height of the surrounding plant material. Where weeds are undesirable, maintaining a four-to six-inch layer of mulch over the soil will help prevent weed growth. Maintaining this I ayer through annual applications, will help control most of the weed problems. Unless they are competing with more desirable ornamental and native plants, weeds in natural stands should not pose a problem. To remove any unwanted weed that does germinate, hand pulling is the most effective method. Spraying pre-or post-emergents are notr ecommended and should not be necessary if both the soil and tree environments are healthy. Maintenance Maintaining trees and understories appropriately in the Grove is important for fire prevention. Remove dead and dying vegetation in both the understory and tree canopy. Deadwood is highly flammable. Logs left for habitat value in the Natural Stands should be a minimum twelve-inches in diameter and ten-feet long. Reduce all other felled tree parts to top dressing or remove from the site within 48 hours after they are cut. Evenly disperse chipped tree parts as understory mulch within the Grove. The mulch layer shall not exceed six inches deep. Chipped particles shall be between one-and eight-inches in length and not greater than 1 ½-inches in width. Keep grasses and weeds under six-inches in perimeter areas of the Grove, especially in the summer and fall when, without irrigation, they become brittle and dry. Cut stumps to less than six-inches above grade. Where stump sprouting is not desired, stumps should be ground to twelve (12) inches be low grade.They should not be treated with an herbicide as this may kill adjacent trees. Keep all building roofs located within, or adjacent to the Grove, free of litter. Provide a water system in the non-irrigated sections, either large agricultural irrigation heads or additional fire hydrants,t hate an be turned on for fire suppression or fire prevention. All fuel powered tools and vehicles should have spark arresters. Vehicles without spark arresters should stay on paved roads. Maintain and make available fi re suppression equipment for all personnel working within the Grove. Fire suppression equipment should consist of: one belt-type fire CARLSBADCOMMUNITYFORESTMANAGEMENTPLAN APRJL2002 PAGE56 through proper planning. All trees should be out side of staging areas. When this is unavoidable,t he following tree protection measures may be employed: Erect a temporary single-strand fence and tree protection signs around trees. The temporary fence should be four feet (4') tall flourescent webbing placed beyond the dripline at a minimum of ten feet from the trunk on all sides of all preserved trees. Tree protection signs are to be attached to the fencing every twenty feet.This will delineate the Tree Protection Zone and prevent unwanted activity in and around the trees. Preventing unwanted activity will reduce soil compaction in the rootz ones of the trees and other damage from heavy equipment. • Avoid heavy equipment operation around the trees. Operating heavy machinery around the root zones of trees will increase soil compaction, which decreases soil aeration and subsequently reduces water penetration in the soil . All heavy equipment and vehicles should, at minimum, stay out of the Tree Protection Zone. • Avoid draining or leakage of equipment fluids near retained trees. Fluids such as: gasoline, diesel, oils, hydraulics, brake and transmission fluids and glycol (anti- freeze) should be disposed of properly. Keep equipment parked or stored atl east5 0 feeta way from retained trees to avoid the possibility of leakage of equipment fluids into the soil. The effect of toxic equipment fluids on the retained trees could lead to decline and may lead to tree death. All grounds-staff and contractors should be notified of this requirement. • Avoid changing grade, including adding fill, within the Tree Protection Zone. Lowering the grade within thi s area will necessitate cutting main support and feeder roots, jeopardizing the health and structural integrity of the tree(s). Adding soil, even temporarily, on top of the existing grade will compact the soil further.a nd decrease both water and air availabil ity to the trees' roots. Remove excess debris. Do not store supplies, materials, etc. within the Tree Protection Zone. Remove any debris from under the drip line of the trees to reduce the chances of tree decline. It is important, however, to leave the duff, mulch, chips, and leaves around the retained tree s for water retention and nutrients. Keep all mulch, however, eighteen-inches from the trunk. Provide supplemental irrigation system. Irrigating the trees before, during and after construction is essential to improve tree health and decrease their susceptibility to water stress and pest infestation. One person should be designated and responsible for irrigating (deep watering) the trees and proper functioning of the irrigation system. The trees should be deep watered every ten-to twenty-days (adjusta ccordingly in wet winter periods). One irrigation period should thoroughly soak the root zones of the trees to a depth of three-feet.To avoid runoffa nd to achieve good infiltration, irrigation controllers will need to be set for repeat cycles. The soils' composition, degree of slope and weather data (can be obtained from California Irrigation Management Information System) will dictate the length of each cycle. Construct berms around retained trees if flood irrigating by hose or water truck.The purpose of the berm is to create a large enough water holding basin to supply the tree with sufficient water. The berms need to be a minimum of six-feet away from the base of a trunk. The berms should be twelve-inc hes in height and eighteen- CARLSBADCOMMUNITYFORESTMANAGEMENTPLAN APRIL2002 PAGE59 inches across. Thin and corrective prune the trees to shape, remove defects such as irregular crowns, deadwood and broken limbs, and correct any damages resulting from r,onstruction activities. All pruning should be performed under the supervision ofa n ISA Certified Arborist and according to ISA guidelines. Plan properly for any understory. Do not plant any plant or tree in a container size greater than five-gallon within the ten-foot protection zone as they will compete with the recovering tree for water and nutrients. SoilType In their native habitats the red and sugar gum eucalypts are found on a variety of soils but perform best in skeletal or podsolic soils, frequently rather shallow. They are also found on solonized brown soils, deep sand, and on ironstone gravels.In 1973 the U.S. Department ofA griculture mapped the surficial soils in Carlsbad Hosp Grove area. The predominants oil type was found to be Carlsbad (gravelly loamy sands) and Chesterson (fine sandy loam with clayey subsoil) series. A third series, Gaviota (fine sandy loam) was also found In order to establish additional species selected for inclusion in reforesting Hosp Grove, soil amending and improving will be required. Additionally, the allelopathic affects of eucalyptus must be tested to avoid large-scale failure of new tree plantings. Soil Sampling Soil sampling may be necessary for determining appropriateness of recommended tree species in the Grove. Amendments can be determined from proper sampling. Soil conditions can be measured both by observation and quantitatively by chemical assay. All soil samples can be sentt o labs for chemical and physical analysis. The tests typically include the following: pH in saturated extract paste; electroconductivity on saturated extract; soluble boron, sulfate, sodium,c alcium,m agnesium and potassium; nutrients/toxic elements measurement of DTPA extract for minor elements; sodicity; soil texture and organic matter estimate; presence of lime determined. Labs also analyze samples of plant tissue (leaves) from a healthy tree, from a declining tree, and from a tree afflicted with unknown maladies. The tissue analysis provides a better picture at what the tree is actually up-taking or using in the soil. Generally, the soil in Hosp Grove is clay-loam to sandy-loam, a fine to heavy soil subject to compaction and its related problems. It has small sized particles that are slow draining, have low aeration, and have high water and nutrient holding capacities. A high clay content soil has a low rate of infiltration with increased runoff. Clay soils are prone to problems with drainage, over-watering, limited oxygen for root development, and compaction. It holds a high content of water reducing the level of soil air and thus is susceptible to septic conditions. Plants will CARLSBAD COMMUNITY FOREST MANAGEMENT PLAN APRJL2002 PAGE60 Irrigation Management Annually on average, Hosp Grove receives one-half the amount of rainfall (10½ inches) than the eucalyptus' native habitat in Australia (20 and 26 inches). Moreover, in Carlsbad most of the rainfall is received in a three to four mo nth period rather than fairly evenly throughout the year in Australia (50-to 75-percent of it in a seven-month period). With this less-than-optimal amounto fw ater,i rrigation is necessary. Otherwise, the trees are under continual stress and therefore more susceptible to long-horned beetle attack, diseases and other maladies. Because oft he soil configuration in this area, water does not naturally occur in underground reservoirs ata depth where itm ightb e available to the trees. lnigation System For optimum health, all the eucalyptus trees and newly planted trees should have supplemental irrigation regardless of their spacing; even the more drought tolerant species require more than 10½-inches of water annually for optimum health. Since the Hosp Grove receives an average of 1 0½-inches of rainfall a year.and seventeen or more inches are needed for adequate health and growth of eucalyptus and young trees of other species, the irrigation system must provide at least seven inches of water a year. This should be the minimum. Irrigation needs increase in direct proportion to the number of trees per acre and the average tree size. Thus, a grove of similar-sized trees spaced twelve-feet on center will require more water than if it was spaced twenty-feet on-center. Also, larger trees require more water than smaller trees because they have more mass to sustain. Newly planted trees require more frequent irrigation for the first two to three years until fully established. When irrigation systems are installed,t he following watering schedule is recommended for the three management approaches. The amount of water indicated shall be applied over and above the normal amount of rainfall. Apply eight-inches of irrigation water annually to trees in all areas. Three fourths of the supplemental water should be applied between the months of October and April. The remaining one-fourth should occur during the hot summer months. For each year, begin tracking rainfall and irrigation water applied October 1. If spring months prove to be unusually wet, less water will need to be applied during the summer. Water should be applied slowly (to avoid run-off) to a depth of three feet and allowed to dry- out between waterings. A soil probe can help determine the amount of moisture in the soil. Because of high soil compaction a power auger may be necessary to obtain soil samples for moisture analysis at a 24" depth. Irrigation run times will depend primarily on the amount of soil compaction, slope, type of irrigation system, and head/nozzle spacing. Water management will rely primarily on the experience of the designated staff person. Initially, it will require keen observation and sampling to determine the necessary run-times for each area. Sampling is best done using a power auger or other coring device. Either potable or reclaimed water can be used. If reclaimed water is used, nozzles and emitters might have more frequent buildup of mineral deposits, and thus, should be inspected more frequently. CARLSBADCOMMUNITYFORESTMANAGEMENTPLAN APRIL2002 PAGE63 Because of expected high soil salinity throughout the Grove, initial leaching is recommended. Thereafter, leaching frequency can be recommended by soil analysis. The soil might require more frequent leaching if reclaimed water is used. A spray irrigation system using rotor spray heads is recommended rather than a drip system mainly because it will disperse water more evenly over the entire root zone. Spray heads are also easier to inspect and maintain, are more durable and can be easily located when trenching or tilling. On the other hand, above ground spray heads will spray water on the tree trunks (a situation that can promote growth of tree attacking fungi) and are more subject to vandalism than a subsurface system. Either system will provide superior growing environments for the trees than currently available in Hosp Grove. The irrigation system to be utilized will likely include a combination of quick couplers, spaced at 150-foot intervals, supplemented as needed by hand and truck watering based on site constraints and economics. If a non-drip system is used, Hunter rotor heads (PGM-06) or similar is recommended. Heads should be designed to pop-up 6 inches or greater in order for the water spray to clear any low growing understory and mulch layer. The selected head type, nozzle and spacing should achieve an 80 to 100% spray overlap. To avoid runoff, the spray should be low volume with repeated applications. The controller should allow for three or more repeat cycles. In moderate to high traffic areas, risers, piping and joints should be flexible rather than the traditional PVC. Where cost prohibits installing an irrigation system and yet supplemental water is necessary for tree health, flood irrigation using a water truck is recommended. Strategically located earthen berms can help channel, contain and evenly disperse the water. Tree Maintenance and Trimming After tree removal for thinning purposes, the remaining preserved trees in high traffic areas such as adjacent to trails, playground, and picnic areas should be pruned to remove deadwood, hazardous limbs, and low growing limbs (for fire safety). In highly visible areas pruning should also be done to promote a nicer looking canopy structure. "Ornamental type" character pruning and structure pruning, (not "cookie cutter") is the desired end product; trees should be pruned to accentuate their natural character as individual specimens as well as part of a group. They should not be pruned to look identical in shape and size. As currently practiced by the City, International Society of Arboriculture pruning standards should be followed at all times. Refer to Appendix E for pruning specifications, illustrations regarding proper types of cuts, and description of various pruning treatments that will need to be employed. All pruning should be performed under the supervision of ISA Certified Arborists and ideally made by ISA Certified Tree Workers. Currently, the trees in the Grove are not maintained; only dead and hazardous trees are removed. Where finances permit, the established eucalyptus trees (over 25 feet in height) should be routinely inspected and crown cleaned every five-to seven-years. In highly visible areas, crown restoration and crown thinning may also be needed to promote a nicer form. Trees in areas adjacent to streets will need crown raising for pedestrian and vehicular CARLSBADCOMMUNITYFORESTMANAGEMENTPLAN APRIL2002 PAGE64 clearance and fire safety. Following planting, young Grove trees should be pruned for crown development every year for the first four years. Tree pruning should occur between November and March when the Eucalyptus Long-horned Borer beetle is less active. If any tree pruning or removal activity is scheduled to be performed between January and June, the trees must be inspected for bird-of-prey nests. If active nests are found, planned activity may be limited or restricted. Each of the above pruning treatments can be done to different levels of detailo r refinement. Except in highly visible trees, an occasional undesirable branch width of 1" or less (base diameter) may be left within the tree crown. The removal of many small branches rather than a few large branches will require more time, but will produce a less-pruned appearance, will force fewer watersprouts and will help to maintain the vitality and structure of the tree. The trees in the Hosp Grove should never be topped. Topping (or "pollarding") is the drastic removal or cutting back of large branches using heading cuts. The tree is pruned like a hedge or rose bush; main branches are cut to stubs. Topping stimulates the regrowth of structurally unsound, dense upright branches that are more susceptible to disease and insects. Topping permanently disfigures the tree and severely depletes the tree's food- making potential. The resulting large branch stubs seldom heal leaving the tree vulnerable to insects and decay. Waste Management All trimmings, debris and other vegetation resulting from tree removal and trimming operations shall be promptly removed from the work site (except for top-dressing mulch) and properly disposed of. The waste generated from these removals can be transformed into valuable products for reuse elsewhere. Small branches and leaves should be chipped and screened to a four-inch minus size and redistributed as a top-dressing mulch. Maintained at a four-to six-inch layer, this mulch will help retain water and suppress weeds. Mulch should be kept 18-inches away from all tree trunks. The raw greenwaste material can also be composted through regular hot beds or by vermiculture to create a weed and seed-free, organic soil amendment. In Australia, Sugar Gum logs are used for pole, posts, general construction, railway sleepers and farm timber. The wood has a fine, uniform texture with interlocked grain. It is hard, heavy and of moderate strength and durability with a density about 1100 kg m-3. A portable bandsaw mill and kiln (similar to the one owned and operated locally by California Department of Forestry and Fire Protection) may be appropriate for salvaging removed trees and producing useable materials. Lumber from the trees can be used throughout the City as pathway borders, signs, picnic benches and tables, furniture and other construction projects. Pest and Disease Control Hosp Grove eucalyptus trees, many of which will remain within the Grove throughout the removal and reforestation effort, are subject to attack from various pests and disease. The most significant of which are: Eucalyptus lerp psyllid, Long-horned borer beetle, Snout-nosed beetle, and Slime flux. Generally, trees with good vigor, low stress, adequate hydration, and proper pruning cuts will be more resistant to pests and disease. As such, the recommendations previously discussed will help improve growing environments for existing and newly established trees, reducing their level of stress and susceptibility to pests. CARLSBADCOMMUNfTYFORESTMANAGEMENTPLAN APRIL2002 PAGE65 Red Gum Lerp and Other Eucalyptus Psyllids There are several species of psyllid that feed on eucalyptus, the most common and most damaging being the red gum lerp psyllid ( Glycaspis brimb/ecombei). First reported in Los Angeles County in 1998, the psylli d quickly spread throughout California. The psyllids, small insects that suck sap from leaves are native to Australia. Psyllids have attacked several species of eucalyptus since 1998, especially the red and sugar gum trees. The typically heavy leaf infestations cause leaf drop, branch die-back, and can lead to tree death after repeated canopy defoliation. The psyllid derives its name from the white, crystalline shell (lerp) that forms over the insect while it feeds. They often appear as black spots on the leaf due to growth of sooty mold. Control of this insect by chemical or biological means has had mixed success. Chemical treatments have been successfu I in some situations, but is not recommended for large- scale projects or widespread use. Biological control, including the imported natural predator wasp (Psyllaephagus bliteus) has proven largely ineffective due to wasp reproduction problems. Long-homed Beetle First discovered in the United States in 1984 in Orange County, California, mature Eucalyptus long-horned borer beetles (Phoracantha semipunctata and P. recurva) lay their eggs in cracks or under loose bark. Once hatched, the larvae feed in and under the bark. This action produces tunnels that may encircle the tree completely restricting or blocking the exchange of nutrients between the roots and the leaves. This can result in the death of the tree. The larvae change to a pupae and remains 1 %-to 2-inches inside the tree during the winter. Adults emerge in late April through oval-shaped holes. Eucalyptus cladoca/yx appears to be more resistant to Long-horned borer than other eucalyptus species, namely E.globulus and E.viminalis. Additional information can be found in Appendix F. Resistance to the beetle appears to be correlated with the level of moisture in the inner bark. Young larvae are killed as they attempt to penetrate through bark with a high moisture content, but readily mine through drier bark. Therefore, the best defense against beetle attack is to maintain healthy, well-hydrated and vigorous trees. Environmental factors and horticultural practices that cause tree stress (e.g., drought, over-crowding, nutrient deficiency, poor drainage, soil compaction, grade changes, root loss, excess irrigation, over pruning) greatly increase a tree's susceptibility to borer attack. Moreover, trees that have been well irrigated but are suddenly subject to drought appear to be at much greater risk than trees that have always grown under limited moisture conditions. Snout-nosed Beetle The Snout-nosed beetle (Gonipterus scutellatus) was discovered in March, 1994 in Ventura County. The mature beetle feeds on leaves and new shoots of Eucalyptus viminalis, E.globulus, and E.sideroxylon. The insect has not become a serious pest on a large-scale. Other eucalyptus species including E.cladocalyx are susceptible to light damage. Eggs are deposited on young leaves. After hatching, the larvae feed first on the leaf, giving the appearance of leaf miner injury, and later consume the entire young leaves and buds. Since the terminal and apical meristems are consumed, the branch(es) can not re-foliate, thereby resulting in a "witches broomff effect. Mature larvae drop from the foliage and burrow into the soil or leaf litter, to emerge as adults after the first rains. CARLSBAD COMMUNITY FOREST MANAGEMENT PLAN APRJL2002 PAGE66 Similar to Long-horned borer, the best defense against Snout-nosed beetle attack is to maintain healthy, well-hydrated and vigorous trees. Water must be carefully managed; drought and stress conditions avoided. Biological control of the Snout-nosed beetle is currently successful. Slime flux A small portion of the Grove trees have a condition known as "wetwood" or "slime flux". Brown slimy liquid oozes from the tree's trunk or main limbs. Often it is located at the site of an old wound. Slime flux is thought to be caused by a number of reasons including a build-up· of bacteria (perhaps originating in the soil) and a chemical/mineral imbalance in the tree. The oozing liquid supports many kinds of bacteria, yeasts, and fungi. It also contains acids that can be toxic to tree tissues. When the flow persists for some time, much of the bark and cambium underneath the flow is killed. Exact cause is unknown. No known treatments or preventative measures are known. CARLSBAD COMMUNITY FOREST MANAGEMENT PLAN APRIL2002 PAGE67 Chapter 10 -Operation Plan '~ clearly defined action priority list ... precedes most successful achievements." This chapter includes a discussion of an Operation Plan for priority projects identified during preparation of this CFMP. This Operation Plan is based on priority tasks that are recommended for completion within a relatively short period. The priorities are ranked with the consideration of several factors including time sensitivity, resource condition, City ranking and expected project duration, amongst others. This Chapter provides brief descriptions of the projects and statements on efficient project accomplishment. Estimated costs of project accomplishment are also included. In addition, staff roles are clearly defined for each project. A clearly defined action priority list is included in this CFMP because such a list precedes most successful achievements. 1. Street tree inventory Tree inventory is an important component to any urban forestry program. Decision-makers must know what they have, i.e., the number and types of trees, their conditions, and their distribution, in order to make sound decisions to achieve forest goals. The inventory provides this critical tree attribute information. The comprehensive information provided in an inventory includes tree species, trunk diameter, height, canopy spread, maintenance needs, insect or pest problems, approximate ages, hazardous situations, and other important decision-making attributes. The last time a tree inventory was conducted in Carlsbad was 1993. A 100-percent tree inventory should require completion one time. This statement is true if oni)oing maintenance work is regularly updated within the City's database. Over the course of three-to four-years, City crews visit each tree within the Street Tree Assessment District (STAD). While performing maintenance work on the trees, updates to existing tree attribute information should be conducted. This information can then be entered into tree management software, thus providing a complete update every three-to four years. Because the City currently does not have updated tree information, a tree inventory within the STAD is recommended. The inventory should be initiated within the next two fiscal years and may be completed during one intensive field effort or phased over two or more years. Once updated, the City's tree management software should be updated consistently and systematically. If the current tree database software is not user-friendly and is therefore ignored, the City may research new software that eases data upkeep. Tree inventory can be performed with knowledgeable in-house crews, but is often more effectively performed by consultants who are hired to complete the task within a given period. In either case, City staff roles would be largely to provide oversight. A main contact, generally the Public Works Manager, or a designated contact such as the Public Works Supervisor, would be responsible for providing field crews with desired information collection parameters. Field crews should include certified arborists experienced in evaluating street trees and operating digital positioning systems. Once the inventory is completed, data would be provided to the database manager. The new database would be integrated to the tree CARLSBAD COMMUNITY FOREST MANAGEMENT PLAN APRIL2002 PAGE68 management software and would supersede previous versions of the database. Previous versions of the database would be maintained in archives for reference purposes. City staff roles would include the following: Public Works Manager Facilitate meetings with consultant or in-house crews Provide pertinent information and direction Public Works Supervisor Oversee consultant or in-house crew inventory Cooperate with consultant regarding maps and other information needs In-house Inventory Crew Conduct inventory and assessment according to accepted methods Map tree locations according to accepted methods Consultant -if selected Provide inventory crew with knowledge assessing street trees Provide mapping equipment such as GPS or pen-based computers Estimated costs for performing a complete inventory of the ST AD trees is based on a total of 12,000 trees. Costs would be as follows: STAD public rights-of-way Tree Inventory Cost Estimate Task Pre-field information exchange and preparation Field tree inventory -GPS Post-field information processing and database integration Optional software update -user friendly -customized for Carlsbad Administration and project management Estimated Cost with Consultant $ 850 $30,000 $ 3,500 $ 7,500 On-going tree information updates (part of current staff responsibilities) $ 3,000 $ 0 Total $44,850 2. Removal of dead and poor condition trees within Hosp Grove A substantial number of red and sugar gum eucalyptus trees, approximately 8,800 total, have been lost or are in poor condition and will likely be lost from the Hosp Grove due mainly to infestation by red gum lerp psyllid (psyllid) over the last few years. A total of 1,464 dead trees were removed by the Carlsbad Fire Department between July 17 and September 29, 2000. During our inventory, an additional 5,300 trees were identified as dead. More than 3,500 were identified as seriously declining. These trees will require removal. The tree removal program developed by the Fire Department is efficient, effective, and important to continue. Grant money can be obtained for removal purposes and for replanting of the Grove with species that would introduce diversity, while maintaining the park-like setting currently found CARLSBAD COMMUNITY FOREST MANAGEMENT PLAN APRIL 2002 PAGE69 there. Management of the Hosp Grove is discussed in detail in the Hosp Grove Management Plan in Chapter 9. City staff roles would include the following: Public Works Manager Facilitate meetings with Fire Department and Consultant Provide pertinent information and direction to Fire Department Public Works Supervisor Conduct monitoring of tree removal operations Cooperate with Fire Department for equipment Fire Marshall Attend meetings Provide funding Provide equipment -chainsaws, etc. Wild land Hazard Officer Provide site oversight Communicate with California Department of Forestry for cooperation, as necessary Prepare summary report upon completion Parks Department Provide chipper equipment and labor Rainbow California Department of Forestry (CDF) Rainbow Crews Provide labor for tree felling, waterbar construction, clean-up, etc. California Department of Forestry -local foresters/urban foresters Provide funding Provide cooperation Provide oversight Costs associated with tree removal operations can vary ~ubstantially, depending on the type of crew employed to perform the removals. Private tree contractors can remove large numbers of trees in a very short period. However, they cost substantially more money than utilizing CDF Rainbow Crews. For example, the 1,474 eucalyptus trees removed during the year 2000 cost nearly $6,700 using CDF Crews. The estimated private contractor costs for the same number of tree removals would be nearly $50,000. The CDF Rainbow Crews completed the job in three months. A private contractor could complete the same job in two to three weeks. Because time is not of the essence on this project, it is recommended that CDF Rainbow Crews perform the work and be coordinated closely with the City of Carlsbad Fire Department. The Fire Defense Project completed in 2000 should be used as a template for this project. As such, estimated direct costs to complete dead, dying, hazardous tree removals from Hosp Grove are estimated as follows: Hosp Grove Tree removal Cost Estimate Task Equipment CARLSBADCOMMUNITYFORESTMANAGEMENTPL.AN APRIL 2002 Estimated Yearly Cost $7,500 PAGE70 Logistics Signs Labor Total $2,500 $ 250 $14,000 * $24,250 CDF Rainbow Crews provide labor to remove 2,500 trees per year 3.0 Replacement of removed trees within Hosp Grove Tree replacement within Hosp Grove should focus on introducing diversity. Unfortunately, the Grove is a good example of poor species and age diversity. Lack of diversity makes the forest vulnerable to devastation resulting from introduced insect pests, such as the psyllid. Because eucalyptus trees were first planted in southern California from seed and not from seedlings (where pests could hitch a ride), they have enjoyed years of success without any of their native pests from Australia. However, due to the increase in wor1d trade, specifically United States imports, eucalyptus pests are introduced to California at a rate of nearly one per year for the last ten years. This trend will undoubtedly continue. As such, it is important to introduce species and age diversity into the Grove. Following removal of the approximately 8,800 trees that have been lost or are in poor condition and will likely be lost, there will be approximately 5,000 trees remaining in the Grove. The remaining trees were the trees that were in the best condition at the time of sampling and were vigorous enough to withstand repeated attacks by the lerp psyllid. These trees should be monitored for future infestations and be removed should they be lost. The remaining trees will be predominately of two species, Eucalyptus camaldulensis and E. cladocalyx, both species are vulnerable to attacks by psylla, borers, tortoise shell beetle, and possibly new pests that establish in the coming years. There will be many available planting sites once the 9,000 dead and dying trees are removed. Replanting these newly available areas should proceed immediately following removals. Recommended replacement species are presented in Chapter 9, Hosp Grove Management Plan. Fire hazard -open areas with no canopy cover will be subject to native vegetation establishment. These areas should be mulched and weed control provided. Tree planting should be accomplished over the next fifteen years. Not all 9,000 trees would be replaced. Because inclusion of wider spreading canopy trees is recommended, fewer trees would be required. Given the 74-acre size of the Grove, and increasing the average on-center spacing to twenty feet, it is recommended that approximately 10,000 total trees comprise the Grove (versus the estimated total of 16,000 trees that the Grove previously included). Including the 5,000 remaining eucalyptus, an additional. 5,000 to 6,000 trees should be planted. This will provide age diversity to compliment the species diversity. As such, approximately 400 trees would be planted per year throughout the Grove. To introduce even more age diversity, a combination of seedlings, 1-gallon, 5-gallon, and 15-gallon trees can be planted (where irrigation is possible). These trees would likely require supplemental irrigation for up to five years following planting and even longer if drought years follow the establishment period. Where irrigation is not available or cannot be efficiently installed, other means of irrigation including hand watering may be utilized. Areas that cannot be provided irrigation should be left to regenerate naturally over time. CARLSBAD COMMUNITY FOREST MANAGEMENT PLAN APRIL2002 PAGE71 A staff person would need to be dedicated to the irrigation, monitoring, and oversight of the tree replacement program. Funding for staffing and a vehicle designated for Hosp Grove restoration would require procurement. City staff roles would include the following: Public Works Manager Provide oversight and coordination with cooperating agencies. Provide oversight for tree species selection and planting Provide funding Public Works Supervisor Provide monitoring of planted trees and irrigation CDF Rainbow Crew Provide tree planting and irrigation installation labor Costs associated with planting trees will be proportional to the number of trees planted. Providing some wide-spreading canopy trees such as native oak trees will reduce the number of trees required. As such costs are as follows: Tree Replacement Planting Estimated Costs Tasks Planning and logistics Plant material/amendments Planting labor Estimated Yearly Cost $750 $10,000 -$15,000<1) $8,000 -$12,000(2) Irrigation $8,000 -12,500 + one time water meter ($10,000) $6,000 -1 o,ooof3> $32,750 to $50,250/yr Monitoring Total (1lUtilizing 100 each of 15-gal/on and 1-gal/on, and 200 5-gallon trees <2lUtilizing Contractor <3>utifizing City personnel Funding Sources -Grants and Foundations There are numerous opportunities available for cash donations from various non-pro fit groups, foundations, corporations, and government agencies. Obtaining these funds will require diligent efforts to locate, make contact, persuade and follow-up. One person should be assigned this task; or it could be contracted out to a private firm. Good sources to locate potential funders are: the internet, other colleges and municipalities with similar past projects, Funding Advantage and other such journals, foundation compendiums (available at most I ibraries), California/Global R eleaf and corporations with a typically negative environmental image (e.g., chemical, oil, mining). Also, by combining the Grove Improvement Project with another project or changing the emphasis slightly, funds that are targeted for education, wildlife, minority job training, art appreciation, small business promotion, etc. can also be used. Be creative, persuasive and flexible. CARLSBAD COMMUNITY FOREST MANAGEMENT PLAN APRIL 2002 PAGE72 Ott-:::r Funding Sources In addition to the general budget and grants, other sources of cash contribution and in- kind services are available. Some suggestions are listed below. Creativity in finding ways to improve the Grove while meeting the needs/goals of other groups is essential. Special project and endowment funds Local residents and local businesses may contribute toward Grove restoration and improv;3ment. For example, contributors for special rehabilitation can be commemorated with a plaque at the site or in the local paper. Other City projects Whenever possible, Grove restoration funds shou:d continue to be built into all City ccnst:-ucticn projects that are located near th& Grove. Donated labor The City should organize volunteer projects for fund-raising, tree planting, hand- watering, spreading mulch, and inspections to be performed at little to minimal cost. Although organizing, training and supervising volunteer labor can often be a difficult task, the effort is usually rewarding. Moreover, grant agencies and foundations typically like to see the public involved in contributing sweat-equity. In addition to students, some sources for donated labor include: County of San Diego Probation Department ($300/15 person crew/day), San Diego People for Trees, and Urban Corp of San Diego. Donated materials Wholesale tree nurseries and irrigation equipment suppliers (e.g. Rainbird) sometimes are willing to donate a portion of the material needed in exchange for publicity and recognition. 4.0 Public Education and Public Relations Program Public education involves many facets. We've discussed some of the ideas thats hould be implemented in Chapter 2. Staff roles and costs for these programs are provided below. City staff roles would include the following: Public Works Manager Provide funding Provide training Conduct and/or attend tree-related functions Provide press releases CARL~BAD COMMUNITY FOREST MANAGEMENT PLAN APRIL200'J PAGE73 Parks/Tree Supervisor Interface with public Attend tree-related functions Provide seminars/presentations for local groups Consultant Provide professional arboricultural services to represent the City at neighborhood groups, conventions, and seminars, as necessary Public Education Estimated Costs Task Marketing Materials Attendance at events Consultant Miscellaneous expenses Total Cost Estimate $0* $3,000 -$5,000 $0* $120/hour, as needed $1,500 -$3,000 $4,500 to $8,000* *Yearly costs, depend on expenses associated with City staff salaries for marketing and attendance at educational events. Consultants may or may not be retained to provide assistance with public education. As such, consulting fees cannot be estimated at this time. CARLSBADCOMMUNITYFORESTMANAGEMENTPLAN APRJL2002 pA(;E:74