Importance of Terrestrial Arthropods as Subsidies in Lowland Neotropical Rain Forest Stream Ecosystems
Importance of Terrestrial Arthropods as Subsidies in Lowland Neotropical Rain Forest Stream Ecosystems
复制标题
陆生节肢动物作为低地新热带雨林溪流生态系统补贴的重要性
DOI：
10.1111/j.1744-7429.2012.00896.x
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发表时间：
2013
期刊：
影响因子：
2.1
通讯作者：
C. Pringle
中科院分区：
文献类型：
--
作者：
G. Small;P. Torres;Lauren M. Schweizer;John H. Duff;C. Pringle
陆地节肢动物的重要性已被记录在温带河流生态系统，但很少有人知道这些输入的热带河流的规模。从热带森林树冠上落下的陆生节肢动物可能是对热带河流食物网的重要补贴，也可能是营养贫乏的源头河流中氮（N）和磷（P）的重要通量。我们量化了陆地昆虫的输入率在8个流排水低地热带潮湿的森林在哥斯达黎加。在两个焦点源头流，我们还测量了捕获效率的鱼类组合和定量的陆地来源的N-和P-排泄相对于流营养吸收率。陆生昆虫的平均输入率范围为5至41毫克干重/平方米/天，超过了这些研究溪流中水生无脊椎动物次级生产的先前测量值，并且与温带溪流中报告的值相比，全年相对一致。陆地昆虫占了占主导地位的鱼类Priapichthys annectens饮食的一半。虽然terrestrially衍生的鱼类排泄物被认为是一个小通量相对于测量的营养吸收率在焦点流，陆地节肢动物的有效捕获和处理的鱼类提供给当地的流生态系统的营养物质。在许多热带地区，这种水-陆联系可能因森林砍伐而脱钩，这在很大程度上是未知的，但可能是重要的生态后果。
The importance of terrestrial arthropods has been documented in temperate stream ecosystems, but little is known about the magnitude of these inputs in tropical streams. Terrestrial arthropods falling from the canopy of tropical forests may be an important subsidy to tropical stream food webs and could also represent an important flux of nitrogen (N) and phosphorus (P) in nutrient‐poor headwater streams. We quantified input rates of terrestrial insects in eight streams draining lowland tropical wet forest in Costa Rica. In two focal headwater streams, we also measured capture efficiency by the fish assemblage and quantified terrestrially derived N‐ and P‐excretion relative to stream nutrient uptake rates. Average input rates of terrestrial insects ranged from 5 to 41 mg dry mass/m2/d, exceeding previous measurements of aquatic invertebrate secondary production in these study streams, and were relatively consistent year‐round, in contrast to values reported in temperate streams. Terrestrial insects accounted for half of the diet of the dominant fish species, Priapicthys annectens. Although terrestrially derived fish excretion was found to be a small flux relative to measured nutrient uptake rates in the focal streams, the efficient capture and processing of terrestrial arthropods by fish made these nutrients available to the local stream ecosystem. This aquatic‐terrestrial linkage is likely being decoupled by deforestation in many tropical regions, with largely unknown but potentially important ecological consequences.