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

Bolsa Chica Lowlands Restoration Monitoring2007 Annual Report1.2. SOILS/SEDIMENT MONITORINGThe Monitoring Plan does not call for soils monitoring to be initiated until Year 2 of the monitoringprogram. This monitoring will be conducted concurrently with vegetation monitoring in Summer2008.1.3. VEGETATION/HABITAT MONITORINGIntroductionThe distribution, composition, and evolution of vegetation communities and unvegetated habitats arebeing monitored through the use of aerial photography and quantitative transect methods. In order tofacilitate vegetation mapping, false-color infrared aerial photography is being used. The photographicproducts provide base-maps for ongoing field studies and facilitate vegetation community and habitatassociation classification. The imagery is to be acquired each year during the same seasonal andapproximate tidal conditions to allow for a comparison of any changes that occur within the systemand provide the basis for long-term habitat trend analysis.The Monitoring Plan does not call for vegetation monitoring to be initiated until Year 2 of theprogram. However, a single habitat-mapping event was conducted in Year 1 to capture conditionsshortly after the opening of the FTB to the ocean and to serve as a baseline for monitoring habitatevolution in subsequent years.MethodologyTo map vegetated and non-vegetated habitats, the Bolsa Chica study area was contract flown onJanuary 16, 2007 to photograph the site at a scale of 1:4,800 from true vertical position on 9”x9” falsecolorinfrared (IR) film. This monitoring event was intended to document conditions as close aspossible to the opening of the FTB to the ocean. (Future aerial photography will be conducted in Mayor June 2008, when wetland habitat is most easily distinguished, as it remains green and transpires at ahigh rate, while upland vegetation has begun to senesce, turn brown, and precipitously decline intranspiration rates.) The photos were flown at approximately 1430 hours at a measured FTB tide of–0.1m NAVD88. This allowed photography of as much exposed intertidal habitat as possible.Additionally, a single 1:19,344 true color spot aerial photograph was taken coincident with the IRimagery. This photograph assisted in providing an additional tool for habitat interpretation andmapping as well as serving as a base map for all field monitoring efforts and reporting.Following survey flights, the aerial images were digitally scanned and georeferenced to create a tilemosaic image for interpretive mapping. Once the images were correctly registered to the project site,heads-up digitization of vegetation boundaries was performed to map communities in accordance withCDFG Holland classification codes (Holland, 1986). Additional codes were used as necessary tosupplement the vegetation codes with biologically important marsh zones, non-vegetated communities,and marine habitats that are lacking in the Holland system. These codes followed the NearshoreHabitat Classification system developed for coastal marine mapping (M&A, 2003).The draft digitized habitat maps were printed and taken into the field for ground-truthing. Oncecompleted, the habitat maps were updated and map products and summary statistics of habitat acreageand distribution across the various project components were generated. Future mapping efforts willexamine habitat change relative to spatial and numeric parameters reported here.Merkel & Associates, Inc. 18