Lussier Suzanne M, da Silva Sara N, Charpentier Michael, Heltshe James F, Cormier Susan M, Klemm Donald J, Chintala Marnita, Jayaraman Saro
Office of Research and Development, National Health and Environmental Effects Laboratory (NHEERL), Atlantic Ecology Division (AED), US Environmental Protection Agency, Narragansett, RI 02882, USA.
Environ Monit Assess. 2008 Apr;139(1-3):119-36. doi: 10.1007/s10661-007-9820-1. Epub 2007 Jun 13.
Watershed land use in suburban areas can affect stream biota through degradation of instream habitat, water quality, and riparian vegetation. By monitoring stream biotic communities in various geographic regions, we can better understand and conserve our watershed ecosystems. The objective of this study was to examine the relationship between watershed land use and the integrity of benthic invertebrate communities in eight streams that were assessed over a 3-year period (2001-2003). Sites were selected from coastal Rhode Island watersheds along a residential land-use gradient (4-59%). Using the rapid bioassessment protocol, we collected biological, physicochemical, habitat, and nutrient data from wadeable stream reaches and compared metrics of structure and integrity. Principal component analyses showed significant negative correlation of indicators for stream physicochemical, habitat, and instream biodiversity with increasing residential land use (RLU) in the watershed. The physicochemical variables that were most responsive to percent RLU were conductivity, instream habitat, nitrate, and dissolved inorganic nitrogen (DIN). The positive correlation of DIN with percent RLU indicated an anthropogenic source of pollution affecting the streams. The biotic composition of the streams shifted from sensitive to insensitive taxa as percent RLU increased; the most responsive biological variables were percent Ephemeroptera, percent Scrapers, percent Insects, and the Hilsenhoff biotic index. These data show the importance of land management and conservation at the watershed scale to sustaining the biotic integrity of coastal stream ecosystems.
郊区流域的土地利用会通过河流水生栖息地退化、水质恶化和河岸植被破坏影响河流生物群。通过监测不同地理区域的河流生物群落，我们能够更好地理解和保护我们的流域生态系统。本研究的目的是考察在三年期间（2001 - 2003年）对八条溪流进行评估时，流域土地利用与底栖无脊椎动物群落完整性之间的关系。研究地点从罗德岛沿海流域沿着住宅用地利用梯度（4% - 59%）选取。使用快速生物评估方案，我们从可涉入的溪流河段收集了生物、物理化学、栖息地和养分数据，并比较了结构和完整性指标。主成分分析表明，随着流域内住宅用地利用（RLU）的增加，河流物理化学、栖息地和河内生物多样性指标呈显著负相关。对RLU百分比反应最敏感的物理化学变量是电导率、河内栖息地、硝酸盐和溶解无机氮（DIN）。DIN与RLU百分比的正相关表明存在影响溪流的人为污染源。随着RLU百分比的增加，溪流的生物组成从敏感类群转变为不敏感类群；反应最敏感的生物变量是蜉蝣目百分比、刮食者百分比、昆虫百分比和希尔森霍夫生物指数。这些数据表明在流域尺度上进行土地管理和保护对于维持沿海溪流生态系统生物完整性的重要性。
