科研之友
微信
新浪微博
Facebook
分享链接
摘要
Macroinvertebrate assemblage characteristics and other biophysical features were measured in the open-water zone of 17 semipermanent/permanent prairie pothole wetlands in Iowa. Relations among variables were used to identify likely determinants of invertebrate abundance and diversity, and useful indicators of wetland condition (i.e., health). Abundant invertebrates included physid and planorbid snails, oligochaetes, leeches, caenid mayflies, corixid bugs, chironomid midges, and amphipods. Abundant taxa were distributed across multiple functional feeding and habit groups. Invertebrate densities and taxonomic diversity were positively associated with plant/coarse particulate organic matter (plant/CPOM) abundance, and negatively related to turbidity, water-column concentrations of nitrogen and phosphorus, and presence of large-bodied fishes. Results supported hypotheses that plant/CPOM was an important invertebrate resource, and that plant/CPOM abundance was reduced in turbid, hypereutrophic wetlands. Fish likely reduced invertebrate abundance and diversity through predation and/or cascading effects on plants, turbidity, and nutrients. Wetlands with high invertebrate abundance and diversity, abundant plant/CPOM, low turbidity and nutrient concentrations, presence of tiger salamanders (Ambystoma tigrinum), and absence of large-bodied fishes appeared to be in the best condition. These features should be routinely measured to effectively assess condition of Iowa prairie pothole wetlands. Additionally, eliminating non-native fish populations may be critical to improving condition of these wetlands.
- 出版日期2010-6
