2007 Annual Monitoring Report (pdf 16MB) - Bolsa Chica Lowlands ...

Bolsa Chica Lowlands Restoration Monitoring2007 Annual ReportResultsEight vegetated and seven non-vegetated habitats were mapped within the 402-hectare (994-acre)study area. Vegetated habitats included: southern coastal salt marsh, disturbed coastal salt marsh, mulefat scrub, coastal sage scrub, freshwater marsh, southern arroyo willow riparian forest,decaying/transitional vegetation, and non-native vegetation. Non-vegetated habitats included: saltpanne, disturbed salt panne, intertidal sand shoal, intertidal mudflat, open water, unvegetated nest site,and urban/developed. Figure 1-3 presents the habitats mapped on-site, and Table 1-1 summarizes theacreage of each. The following text describes each habitat in detail.Table 1-1. Area of habitats within the Bolsa Chica study area (January 2007).Habitat Hectares AcresSouthern coastal salt marsh 92.2 227.7Disturbed southern coastal salt marsh* 7.3 18.1Mule fat scrub 0.5 1.3Coastal sage scrub 0.5 1.3Coastal and valley freshwater marsh 2.1 5.3Southern arroyo willow riparian forest 0.3 0.7Decaying/transitional vegetation* 21.7 53.6Non-native vegetation 2.1 5.2Salt panne* 67.4 166.6Disturbed salt panne* 7.3 18.1Intertidal sand shoal* 1.8 4.4Intertidal mudflat* 40.1 99.1Open water 89.3 220.8Unvegetated nest site* 8.4 20.8Urban/developed 61.0 150.7*Additional non-Holland habitat codes used to further break out biologically relevant habitat types.Southern Coastal Salt MarshWhile the majority of the habitat within Bolsa Chica can be considered southern coastal salt marsh,most is not a truly intertidal marsh: one that experiences regular tidal seawater influence. Within themajority of the study site, recognizable zonation of the salt marsh is no longer present due to theabsence of tidal influence. Continuing to persist in these areas are species that are tolerant of highlysaline soils. This relictual marsh is almost entirely composed of large expanses of pickleweed(Sarcocornia pacifica and Arthrocnemum subterminale). The pickleweed quality varies throughout thesite from tall and robust, to short in stature and desiccated. Other common species in the salt marshinclude: salt grass (Distichlis spicata), saltwort (Batis maritima), and alkali heath (Frankenia salina),The majority of this salt marsh habitat is of moderate quality based on its fairly expansive nature andlimited infestation by exotic and upland species. While there is very little plant diversity within thishabitat, such conditions are normal for coastal salt marsh habitats and especially so for non-tidalmarshes that experience hypersaline sediment conditions and the environmental extremes of wet anddry seasons and years.Merkel & Associates, Inc. 19