Flow Regime and the Structure and Productivity of Macroinvertebrate Communities in Tropical Streams

热带溪流中大型无脊椎动物群落的流态以及结构和生产力

• 批准号: 9007845
• 负责人: Bernard Sweeney
• 金额: $ 30万
• 依托单位: Academy of Natural Sciences Philadelphia
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-07-01 至 1993-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9007845&HistoricalAwards=false
• 关键词: Flow; Regime; Structure; Productivity; Macroinvertebrate

This research focuses on the ecological and evolutionary significance of flow regime to macroinvertebrate communities in tropical dry forest streams of Costa Rica. Pristine tropical watersheds are ideal sites for testing the effects of flow on stream communities because the confounding effects of seasonality in temperature and photoperiod and high silt and sediment load associated with most temperate streams are absent, and many pristine small streams with perennial flow regimes are available for study. The research will quantify macroinvertebrate community structure and the life history characteristics and production of all widespread and common species of macroinvertebrates in riffle habitat of six perennial streams. The study will focus on temporal changes in these parameters in response to prolonged (6 month) periods of both constant (dry season) and elevated (wet season) flow as well as to short-term flood flaws during the wet season. The central hypothesis of the study is that: stream macroinvertebrate communities are not oversaturated with species (in the absence of disturbance) and may be capable of withstanding long periods of abiotic stability without loss of diversity, i.e. there is no "paradox of the stream benthos". The principal objectives of this research project are to: (1) quantify seasonal variation in the relative abundance and species composition of macroinvertebrates and test the utility of flow as a covariate for explaining this variability; (2) document the extent of seasonality in macroinvertebrate life histories and evaluate sesonality as an adaptation to flow regime; (3) evaluate the relative importance of storms in explaining seasonal variability in macroinvertebrate community structure (4) assess the role of spatial scale (i.e. patch size) in studies of benthic community succession; and (5) evaluate the role of disturbance in maintaining the diversity of stream communities.

这项研究的重点是哥斯达黎加热带干燥森林溪流中水流状况对大型无脊椎动物群落的生态和进化意义。 原始热带流域是测试水流对溪流群落影响的理想场所，因为不存在与大多数温带溪流相关的温度和光周期季节性以及高淤泥和沉积物负荷的混杂影响，并且许多具有常年水流状态的原始小溪可供研究。 该研究将量化六个常年溪流的浅滩栖息地中大型无脊椎动物的群落结构以及所有广泛和常见的大型无脊椎动物物种的生活史特征和产量。 该研究将重点关注这些参数的时间变化，以响应长期（6个月）恒定（旱季）和升高（雨季）流量以及雨季期间的短期洪水缺陷。 该研究的中心假设是：河流大型无脊椎动物群落没有物种过度饱和（在没有干扰的情况下），并且可能能够承受长期的非生物稳定性而不丧失多样性，即不存在“河流底栖生物悖论”。 该研究项目的主要目标是：（1）量化大型无脊椎动物相对丰度和物种组成的季节性变化，并测试流量作为解释这种变化的协变量的效用； (2) 记录大型无脊椎动物生活史的季节性程度，并评估季节性作为对流动状态的适应； (3) 评估风暴在解释大型无脊椎动物群落结构季节性变化方面的相对重要性 (4) 评估空间尺度（即斑块大小）在底栖群落演替研究中的作用； (5)评估扰动在维持溪流群落多样性方面的作用。