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HomeMy WebLinkAboutHMP 05-06; CASSIA PROFESSIONAL OFFICES; YEAR 2 REVEGETATION MONITORING REPORT; 2009-12-09Year 2 Revegetation Monitoring Report Cassia Professional Offices December 9, 2009 1.0 Summary of Results This annual report documents the status of revegetation described in Upland Habitat Revegetation Program, Cassia Professional Offices, Carlsbad, California, February I 0, 2006, by Planning Systems. Mitigation measures required of this project consist of the following: a) Preservation -of 1.36 acres of existing on-site habitat b) Fee Payment c) Revegetation of 0.10 acres of upland habitat -This revegetation is not proposed as mitigation for project related impacts, all habitat mitigation is provided for through on-site preservation. Rather, the revegetation is installed as an erosion control planting intended to stabilize soil disturbed by the temporary construction impacts. The intent of the revegetation is to introduce and provide for the establishment of native plant species which closely reflect the biological character of adjacent existing native vegetation. A plant palette compositionally similar to the adjacent preserve habitats shall be utilized. The 0.10 acre revegetation area will be installed with new container plants and seed designed to closely replicate the composition of existing upland habitat in the adjacent preserved conservation area. The findings of this report are based on biological monitoring by Planning Systems that occurred on December 9, 2009. The criteria used to evaluate the success of the project are the project performance standards described in the Revegetation Program. Year 2 project performance is summarized in Table 1 below. Table 1 -Mitigation Success Evaluation Year 2 Per:ihrmance standards Results to date Criteria Attained 50% achievement of ultimate cover of native species 30% to 60% cover Partially Shut off supplemental irrigation by end of second dry season irrigation ongoing No No highly invasive species present; maximum 10% ultimate 2 invasive No cover of weeds species present 2.0 Introduction The Cassia Professional Offices are located in Carlsbad, California (see figure 1). The project revegetation installation was complete on approximately April 1, 2008. One year later, on April 15, 2009, Planning Systems monitored the revegetation and determined that remedial measures were needed to assist the project meet its performance standard requirements and to qualify for tum over to the Conservation manager. The Planning Systems recommended remedial work was implemented by June 15, 2009 and included the following: 1. Installation of (150) Black sage (Salvia melifera). 2. Installation of (50) Coast sage brush (Artemesia californica). 3. Exotics removal. 4. Irrigation system repair. Year 2 Revegetation Monitoring Report, Cassia Professional Offices, 12-10-09 2.1 Monitoring Methodology Monitoring methodology required of the revegetation is as follows: 1. Quarterly Assessments -which include the following evaluations: a. Irrigation system b. Trash/vandalism c. Weed infestation d. Erosion e. Pests/Disease f. Container survival g. Cover of indicator species h. percent of key species (dominant and sub-dominant) i. Observations/ Recommendations 2. Photodocumentation -Permanent stations are established at locations which best capture the revegetation project views (see Figure 2). 3. Performance Standards I year Performance .standard I Year2 50% achievement of ultimate vegetative cover of native species By year-end of second dry season, shut off supplemental irrigation. No highly invasive species present; maximum 10% ultimate cover of weeds considered not a threat to displace native vegetation. I Year 3 50% achievement of ultimate vegetative cover of native species. 100% survival ofremaining dominant/sub-dominant species (Table B, p. 9) No highly invasive species present; maximum 10% ultimate cover of weeds considered not a threat to displace native vegetation. Qualitative Monitoring Monitoring sampling methods are not prescribed in the revegetation program. For this report, qualitative monitoring was utilized, which is the collection of data by visual assessment. 3.0 Monitoring Results On December 9, 2009 Planning Systems monitored the revegetation to collect data for this report. Greg Evans, restoration ecologist, performed the assessment. 3.1 Qualitative Assessment 1. Irrigation System -The system was not observed in operation, but its function is satisfactory enough that containers installed on June 15, 2009 are growing. No sizable bare areas that would indicate poor irrigation performance were observed. 2. Trash/ Vandalism -None observed 3. Weed Infestation -Very limited naturally-occurring weed cover exists, estimated at presently less than 3% (see Section 5.2 for weeds to remove> Year 2 Revegetation Monitoring Report, Cassia Professional Offices, 12-10-09 However, a cultivar ofBaccharis pilularis (probably Baccharis pilularis 'Twin Peaks') was planted as a ground cover throughout the plot as an erosion control measure. This cultivar is interdigitated with natives and presently covers over 90% of the plot surface area. In an erosion control setting this plant is well placed, but in native habitat this plant is a weed. However, it is not a weed that will ultimately survive in a non-irrigated setting and when taller natives overtop and shade this ground cover. It is presently assisting the project in providing erosion control and in suppressing weeds, so at this time it will be tolerated. This cultivar will not reproduce like other weeds and will eventually die off once horticultural practices utilized in growing the revegetation are discontinued. In terms of vegetative cover assessment for this report, this plant will be ignored in the data set. 4. Erosion -A severe rain storm occurred on December 7, 2009 which made evident one area that needs additional erosion control. The storm drain channel immediately below the outfall box is experiencing erosion of soil that needs corrective action to stop the problem while still small. See recommendation Section 5.5 for recommended actions. 5. Pests/Disease-None observed 6. Container survival -Table 2 below lists the quantities of container installed by species and their survival rate to date. A year 1 requirement of this project was "80% survival of installed container material unless their function and value has been replaced by natural recruitment". To meet this year 1 requirement, 200 remedial containers were installed in June 2009. Based on existing plants ( counted for this report), the container survival rate of all species planted (when tallied together), is now greater than 80% survival. Table 2 -Survival Rate of Containers installed Latni N aiile Coniinon Name Initial Rertiedia1 Existfog planting planting ( established or volunteered) Artemesia californica Coast sage brush 0 50 213 Baccharis pilularis Coyote brush 0 37 Baccharis salicifolia Mulefat 0 2 Erio~onum fasciculatum * Flat-top Buckwheat 20 7 Heteromeles Toyon 15 11 arbutifolia* Mimulus aurantiacus * Monkeyflower 20 13 Ouercus berberdifolia* Scrub oak 15 1 Rhus intewifolia* Lemonadeberry 20 2 Rhus ovata Sugar bush 20 13 Salvia mellifera * Black Sage 20 150 115 Yucca schidif{era* Mohave yucca 15 9 't.<)f.ALS ---125 200 -420 *Key Species are shown with an asterisk. 7. Cover oflndicator Species -For this project cover is estimated qualitatively (by visual estimate). Across more that 1/2 of the plot native cover is approximately 50%. For the remainder of the plot, the cover is in the 30% to 50% range. Therefore, the Year 2 performance standard 50% ultimate vegetative cover of native species" has not been met. However, in terms of native plant density, the distribution of individuals across the plot is very good. This is due to several factors including, 1) establishment of the remedial plantings installed in June 2009, 2) volunteering of natives across much of the plot, and 3) supplemental irrigation delivered Year 2 Revegetation Monitoring Report, Cassia Professional Offices, 12-10-09 throughout this past dry season. As the existing native plants develop into mature sized plants, it is anticipated that the cover requirement of "50% ultimate vegetative cover of native species" will be easily met. Therefore, no additional remedial plantings are recommended by this report. 8. Percent of Key Species ( dominant and sub-dominant) -Key species are identified for this project as the species listed in "Table B: Container Plants" in the revegetation program (which are shown with an asterisk in Table 2 above). Species performing as dominants to date are: Black sage (Salvia mellifera), and Coast sage brush (Artemesia califomica). The species performing as a sub-dominant to date is: Coyote brush (Baccharis pilularis). All "Key Species" listed in the revegetation program continue to be represented on the plot, but not in the numbers installed. Given that the project mitigation requirement is to establish an "erosion control planting", producing native cover has been the focus ofremedial plantings rather than species composition. Therefore when remedial plantings were recommended, upland native species most readily adapting to the project site were installed. This is why Black sage and Coastal sagebrush were used as remedial species, and why they are now the dominant species of the plot. In the case of the sub-dominant Coyote brush, this native species has volunteered to the plot, indicating superior adaptability to the plot. 4.0 Conclusions This project does not yet meet its performance standard requirements. For the project to be released it must achieve the following: 1. Native species must produce additional cover such that 50% ultimate cover is realized. 2. Supplemental irrigation must be discontinued. The revegetation program performance standard recommends discontinuing supplemental irrigation after the second year of growth. However, given that young containers installed in June 2009 have not been in the ground for even one full year, discontinuing irrigation at this time may lead to death. By the fall of 2010 these remedial containers will be sufficiently established to survive without irrigation. 3. Two highly invasive species are present, Tamarisk (Tamarisk sp.), and Pampas grass (Cortaderia selloana). These species must be removed as soon as possible. Other weeds are under control and at this time and do not represent a threat to the revegetation establishment. 5.0 Recommendations The following recommendations are provided to assist the project in meeting its performance standard obligations and for the project to qualify for release to the long term manager: 1. Irrigation -Continue supplemental irrigation as necessary to assist revegetation growth and establishment. During the coming winter, do not apply irrigation unless plants are wilting. The maintenance contractor should visit the revegetation site at least once a month during the coming year and adjust the irrigation schedule to apply water as necessary to: 1) maintain active plant growth through June 2010, and 2) to ensure that plants do not experience severe drying out during the summer and fall. Quarterly monitoring reports will continue to direct the contractor in irrigation management. 2. Weed Infestation_-Remove the following species observed. Do not allow any weeds to mature beyond the flowering stage. Allow no weed seed to set. a. Pampas grass (Cortaderia selloana) b. Salt cedar (Tamarisk sp.) Year 2 Revegetation Monitoring Report, Cassia Professional Offices, 12-10-09 c. Sow-thistle (Sonchus sp.) d. Hollow-stem asphodel (Asphodelusfistulosus) e. Tree tobacco (Nicotiana glauca) f. Short-pod mustard (Hirsfeldia incana) g. Flax-leaffleabane (Conyza bonariensis) 3. Baccharis Cultivar Management -Weed whip all baccharis cultivar plants to 6" above grade and maintain this height throughout the year. Do no weed whip any vegetation prior to the revegetation ecologist conducting a session to educate the workers that will operate the equipment. 4. Prune Encroaching Ornamentals on Walls -Prune all Myoporum ground cover (Myoporum parvifolium) and Creeping fig (Ficus pumila) from the plot finish surface and up the wall such that thee ornamentals are not within 3 feet of any native plants. 5. Repairing Erosion Damage-Install fabric over exposed bare ground at the base of the storm drain outfall structure (see figure 2). Secure in place with metal anchors and sand bags as necessary. 7 .O References Hickman, J.C., Editor, 1993, The Jepson Manual, Higher Plants of California. University of California, Berkeley, CA, pp. 1392. Holland, R.F., 1986, Preliminary Description of the Terrestrial Natural Communities of California, Unpublished technical report. State of California, The Resources Agency, Department of Fish and Game, Natural History Division, Sacramento, CA. Munz, P.A., 1974, A Flora of Southern California. University of California Press, Berkeley, CA. pp. 1084 Sawyer, J.O. and Keeler-Wolf, T.,1995, A Manual of California Vegetation. California Native Plant Society, Sacramento, CA. pp. 471. Brenzel, Kathleen N., Editor, 2001. Sunset Garden Book. Sunset Publishing Corporation, Menlo Park, CA. pp. 768. Rebman, Jon P ., and Simpson, Michael G ., 2006, Checklist of the Vascular Plants of San Diego County 4th Edition. San Diego Natural History Museum, San Diego, CA. pp. 99. Planning Systems, 2006. Upland Habitat Revegetation Program, Cassia Professional Offices, Carlsbad, CA, February 10, 2006. U.S. Department of Agriculture, Growers Weed Identification Handbook. Publication Number 4030, University of California, Oakland, CA. U.S. Fish and Wildlife Service. 1998. National List of Plant Species that Occur in Wetlands: California (Region 0). Biological Report 88 (26.10). May 1988. Year 2 Revegetation Monitoring Report, Cassia Professional Offices, 12-10-09