Interguild Interactions in Communities of Benthic Stream Invertebrates

底栖溪流无脊椎动物群落间的相互作用

• 批准号: 9628969
• 负责人: Stephen Heard
• 金额: $ 15万
• 依托单位: University of Iowa
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-10-01 至 2000-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9628969&HistoricalAwards=false
• 关键词: Interguild; Interactions; Communities; Benthic; Stream

9628969 Heard The goal of this research is to test some long-standing but poorly supported hypotheses about interactions among invertebrates inhabiting temperate streams. Communities of bottom-dwelling stream invertebrates include organisms with several different feeding strategies. "Shredders" feed on large pieces of organic detritus, such as dead leaves and twigs. "Collectors" feed by filtering small organic particles from the water. Because shredders process larger organic material to small particles as they feed, it has been widely assumed that their presence benefits collectors (increases growth and/or survival). However, recent theoretical work suggests that this is only one possibility. Processing of detritus produces particles in the short term, but also removes material that could yield particles later; therefore, the presence of shredders might be detrimental to collectors, particularly over longer time scales. In the present study, experimental manipulations of shredder densities in natural and artificial streams will be conducted to determine the nature of the shredder-collector interaction in a small stream in eastern Iowa. These will be the first complete, direct field tests of the shredder-collector facilitation hypothesis. A third group of invertebrates, called "grazers", feed by scraping algae from surfaces in streams. These animals also produce particles as they feed, and it has also been assumed that grazers facilitate collector growth or survival. This hypothesis will be tested with grazer manipulations in parallel with the shredder experiments. Understanding interactions among stream invertebrates is important because these organisms have ecological and economic importance beyond the local stream reach. For instance, the study organisms are food resources for aquatic and terrestrial animals including birds, bats, and economically important fish species such as trout and salmon. Some collectors (blackflies) are important pests and disease vectors for wildlife and livestock. Finally, these invertebrates are widely used in assessing and managing stream water quality. Results from this study will increase understanding of interactions among species that are central to this important natural community.

9628969赫尔德，这项研究的目标是测试一些长期存在但缺乏支持的关于温带溪流中无脊椎动物之间相互作用的假说。底栖溪流无脊椎动物群落包括具有几种不同摄食策略的有机体。“碎纸机”以大块的有机碎屑为食，例如枯叶和树枝。“收集器”通过从水中过滤微小的有机颗粒来进食。因为粉碎机在喂食时将较大的有机物质加工成小颗粒，所以人们普遍认为它们的存在有利于收集者(提高生长和/或存活率)。然而，最近的理论研究表明，这只是一种可能性。碎屑的处理在短期内会产生颗粒，但也会去除以后可能产生颗粒的物质；因此，粉碎机的存在可能对收集器不利，特别是在较长的时间尺度上。在本研究中，将对天然和人工溪流中的碎纸机密度进行实验操作，以确定爱荷华州东部一条小溪中碎纸机-收集器相互作用的性质。这将是对碎纸机-收集器促进假说的第一次完整的、直接的现场测试。第三类无脊椎动物被称为“食草动物”，它们以从溪流表面刮取藻类为食。这些动物在进食时也会产生颗粒，也被认为是食草动物促进了收集器的生长或生存。这一假设将在碎纸机实验的同时用放牧机操作进行验证。了解溪流无脊椎动物之间的相互作用很重要，因为这些生物具有超出当地溪流覆盖范围的生态和经济重要性。例如，研究生物是水生和陆地动物的食物资源，包括鸟类、蝙蝠和经济上重要的鱼类物种，如鲑鱼和鲑鱼。一些收集者(黑蝇)是野生动物和家畜的重要害虫和病媒。最后，这些无脊椎动物被广泛用于评估和管理溪流水质。这项研究的结果将增加对物种之间相互作用的理解，这些物种是这个重要的自然群落的核心。