4.1 Article

Hydrology and pool morphology shape the trophic base of macroinvertebrate assemblages in ephemeral stream pools

期刊

FRESHWATER SCIENCE
卷 39, 期 3, 页码 461-475

出版社

UNIV CHICAGO PRESS
DOI: 10.1086/709647

关键词

flow intermittency; food webs; groundwater connectivity; evaporative contraction; aquatic vegetation; stable isotope analysis

资金

  1. Australian Research Council
  2. Rio Tinto [LP0776626]
  3. ARC [FT110100352]

向作者/读者索取更多资源

Intermittent and ephemeral streams in dryland regions often fragment into isolated pools as they dry. In general, pool fragmentation provides favorable conditions for aquatic algae and plant growth and should therefore result in foodweb reliance on aquatic algal resources over comparatively-recalcitrant terrestrial plant litter. However, differences in pool hydrology and morphology might substantially alter organic matter dynamics and, thus, alter the trophic base of aquatic consumers. We tested whether 1) taxa composition or 2) pool hydrology and morphology might affect the trophic base of macroinvertebrate assemblages in dryland stream pools. We used stable isotope analysis to assess the hydrological regime (delta O-18 and delta H-2) and trophic structure (delta C-13 and delta N-15) of fragmented pools within an ephemeral dryland stream. We compared differences in pool morphology, evaporation rates, and groundwater connectivity to dietary-mixing model results for macroinvertebrate assemblages over 2 seasons. Differences in macroinvertebrate assemblage composition were not consistently related to pool hydrology, morphology, or season. We found that filamentous algae and aquatic biofilms supported macroinvertebrate assemblages to a greater extent than did terrestrial plant litter. Biofilm assimilation was higher in highly-evaporated pools, and terrestrial plant litter assimilation decreased as pools became smaller and aquatic vegetation cover decreased. Overall trophic diversity decreased with increasing aquatic vegetation cover. This study suggests that hydrological and morphological gradients across pools drive differences in the trophic base of macroinvertebrate assemblages, potentially through variation in organic matter productivity and biomass. Consequently, natural variability in groundwater connectivity and pool morphology likely enhances trophic diversity across this ephemeral riverscape.

作者

我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。

评论

主要评分

4.1
评分不足

次要评分

新颖性
-
重要性
-
科学严谨性
-
评价这篇论文

推荐

暂无数据
暂无数据