3 - The Bowery_PUBLIC COMMENT_RAMSEY

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5.0 Environmental Analysis 5.2 Biological Resources Avion Project SEIR Page 5.2-4 5.2.2.3 Sensitive Biological Resources a. Sensitive Vegetation Communities Coastal sage scrub, southern mixed chaparral, non-native grassland, and freshwater marsh are all considered sensitive vegetation types under the City (City of San Diego 2012). Coastal sage scrub is ranked as a Tier II habitat, southern mixed chaparral as a Tier IIIA habitat, non-native grassland as a Tier IIIB habitat, and freshwater marsh as a wetland habitat. All these habitat designations require mitigation for impacts to these habitat types. b. Sensitive Plant Species A spring survey to look for sensitive plant species was conducted on the site on March 21, 2018. No sensitive plant species were observed during the spring survey and none are expected to occur on the site. A list of sensitive plant species, including species endemic to San Diego County, with the potential for occurrence on the site is provided in Appendix B - Attachment 3. One sensitive plant species, thread-leaved brodiaea (Brodiaea filifolia), was initially considered to have a potential to occur on the project site solely due to close proximity to a known population to the north that occurs within the Heritage Brodiaea Preserve. The Heritage Brodiaea Preserve population of thread-leaved brodiaea occurs within open space set aside as part of the Heritage Bluffs II development project. Over ten thousand individual thread-leaved brodiaea plants have been documented in this preserve. The thread-leaved brodiaea in the Heritage Brodiaea Preserve occur on heavy clay soils. A focused spring survey for thread-leaved brodiaea was also conducted on the Avion project site on March 21, 2018. Additional focused surveys for thread-leaved brodiaea were conducted on March 14 and April 12, 2019. These surveys were timed to coincide with the emergence and observability of the existing population of this species within the Heritage Brodiaea Preserve. No thread-leaved brodiaea plants were observed on the Avion project site and none are expected to occur. Therefore, there is a low potential for this species to occur on the site due to the following several factors. • Historically Chaparral/Sage Scrub Habitat – A review of historical aerial photographs back to 1953 show that the Avion project area was vegetated with shrublands (i.e., chaparral, coastal sage scrub) while the location of the Heritage Preserve to the north has been grassland to the present. By the mid-1960s the Avion site had an established homestead that cleared the surrounding shrublands for access, buildings, and local agricultural activities. The non-native grassland areas that currently occur on the site colonized some of these disturbed areas once they were abandoned. • Poor Quality Grassland Habitat – The non-native grassland vegetation on the project site has been subject to historical disturbances (e.g., dirt roads, clearing, agricultural activities, homestead, etc.). The non-native grassland that developed after the homestead was abandoned grew a tall, thick thatch that makes it difficult for herbaceous species other than grasses to persist. This grass thatch is much taller and denser than that where the known thread-leaved brodiaea population to the north occurs. The non-native grassland on the site