Natural resource planning and project success assessment often require knowledge of the current status or trends of biological communities. Vegetation, small mammals, breeding bird, and invertebrate communities were studied at the Yuma East Wetlands, a large-scale riparian and wetland restoration project along the lower Colorado River, to evaluate communities before and after restoration activities. Vegetation community characteristics, such as native species survivorship and recruitment, invasive species recolonization, density, species composition, canopy cover, total vegetation volume, structural composition, and habitat potential, were evaluated using a variety of vegetation sampling methods. Some methods included: belt transects, point intercept, plot and nested plot, and random design. Small mammals, birds and invertebrates were monitored every other month for two years in restored, reference and control habitats to compare community characteristics. Statistical analyses evaluated species occurrence and abundance similarity, overall comparison of the variation between abundance and richness among the different habitats, and correlations between wildlife and habitat characteristics.
Additionally, research was conducted to evaluate breeding bird and butterfly communities in restored versus unrestored habitats. Breeding birds were evaluated by using area searches over six surveys during the breeding season. Butterflies were evaluated along timed transects, and nectar resources were identified and quantified. PC Ord and SPSS statistical software was used to analyze differences in species richness, abundance and diversity; bird and butterfly and habitat correlations; and bird and butterfly composition and similarity. This research indicated that planting native understory vegetation benefited both bird and butterfly communities and served to prevent recolonizing invasive species. Biological surveys and research help to inform important decision-making actions in natural resource planning and provide success criteria for implemented projects.
Contributions from Heidi Trathnigg, as an employee of Fred Phillips Consulting, LLC
- Secured grant funding to support biological surveys and research through state funding grants.
- Developed the sampling design, protocol, datasheets, and database for data collection.
- Used malaise traps, pit traps, black lighting, sweep nets to capture diurnal and nocturnal invertebrates. Identified invertebrates to lowest taxonomic level possible, at least Family.
- Served as the Project Manager and managed the field crew.
- Performed all statistical analyses using SPSS, PC ORD, and Microsoft Excel. Graphically displayed data in tables, graphs and charts.
- Interpreted results, graphs and tables and incorporated into the final report.
- Published research in peer reviewed Ecological Restoration journal (Trathnigg, H.K. and F.O. Phillips. 2015. Importance of native understory for bird and butterfly communities in a riparian and marsh restoration project on the lower Colorado River, Arizona 33(4): 395-407).