Life in the fast lane: fish and foodweb structure in the main channel of large rivers
Life in the fast lane: fish and foodweb structure in the main channel of large rivers
复制标题
快车道上的生命：大河主河道中的鱼类和食物网结构
DOI：
10.2307/1468320
复制
发表时间：
2001
影响因子：
--
通讯作者：
S. Gutreuter
中科院分区：
文献类型：
--
作者：
J. Dettmers;D. Wahl;D. Soluk;S. Gutreuter
我们研究了伊利诺伊河下游的主河道和密西西比河与伊利诺伊河汇合处的上游和下游的主河道，以描述主河道群落的丰度、组成和/或季节外观。主航道鱼类丰度较高，成鱼最多。大多数成鱼每年在主航道出现3或4个季节，表明鱼类在主航道中有规律的栖息。我们记录了主水道中丰富的浮游动物和底栖无脊椎动物，以及在斑点叉尾鱼和淡水鱼的食物中存在这些食物类型。所有营养水平在主航道中都有很好的表现，这表明主航道支撑着一个独特的食物网。主航道也是与其他河流生境(如泛滥平原、次生航道、死水湖泊)的重要能量纽带，因为栖息鱼类的移动性，以及为这一食物网提供的各种能源。将大河流系统中的能量流动视为3个现有概念的组合可能更为现实：河流连续体概念(下游传输)、洪水脉冲概念(向漫滩的横向传输)和河流生产力模型(原生生产)。我们敦促开展更多的研究，以量化大河中主河道与其他生境类型之间的联系，因为主河道过程在大河生态系统的整体结构和功能中显然很重要。
We studied the main channel of the lower Illinois River and of the Mississippi River just upstream and downstream of its confluence with the Illinois River to describe the abundance, composition, and/or seasonal appearance of components of the main-channel community. Abundance of fishes in the main channel was high, especially adults. Most adult fishes were present in the main channel for either 3 or 4 seasons/y, indicating that fishes regularly reside in the main channel. We documented abundant zooplankton and benthic invertebrates in the main channel, and the presence of these food types in the diets of channel catfish and freshwater drum. All trophic levels were well represented in the main channel, indicating that the main channel supports a unique food web. The main channel also serves as an important energetic link with other riverine habitats (e.g., floodplains, secondary channels, backwater lakes) because of the mobility of resident fishes and because of the varied energy sources supplying this food web. It may be more realistic to view energy flow in large-river systems as a combination of 3 existing concepts, the river continuum concept (downstream transport), the flood pulse concept (lateral transport to the floodplain), and the riverine productivity model (autochthonous production). We urge additional research to quantify the links between the main channel and other habitat types in large rivers because of the apparent importance of main-channel processes in the overall structure and function of large-river ecosystems.