Structure and functional composition of macroinvertebrate communities in coastal plain streams across a precipitation gradient
Structure and functional composition of macroinvertebrate communities in coastal plain streams across a precipitation gradient
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DOI：
10.1111/fwb.13968
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发表时间：
2022-07
影响因子：
2.7
通讯作者：
F. Carvallo;Bradley A. Strickland;Sean Kinard;B. Reese;J. D. Hogan;C. Patrick
中科院分区：
文献类型：
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作者：
F. Carvallo;Bradley A. Strickland;Sean Kinard;B. Reese;J. D. Hogan;C. Patrick
预计气候变化将改变世界各地的降雨和温度状况。河流生态系统的水文和河岸带植被与降雨密切相关，需要对降雨对河流生态系统的影响有一个机械的理解，以预测气候变化的生态影响。然而，很难将降雨的影响与其他气候变化的环境变量隔离开来。为了解决这一问题，我们利用一个独特的陡峭的降雨梯度，在海拔，温度和地质学的协变变化很少，以评估降雨对流无脊椎动物community.We调查了9流在德克萨斯州墨西哥湾沿岸大草原分布沿着550- 1350毫米/年的降雨梯度的影响。四个地点被归类为较干燥的半干旱河流（年降雨量<750毫米），五个地点被归类为较湿润的亚湿润河流（年降雨量>750毫米）。一套特征，包括底栖无脊椎动物群落指标，流量条件，和水质变量进行了评估，每月在每个站点14个月的降雨制度流结构和functions.Precipitation制度被认为是一个主解释变量。随着年降雨量的增加，流动环境变得更加稳定的季节和跨季节的可预测性，影响空间结构和无脊椎动物群落组成的时间变异。潮湿的溪流中占主导地位的缓慢增长的类群没有适应干燥的阻力和强大的传播。潮湿的网站显示群落组成和物种丰富度的季节性变化，而在干燥的溪流群落的时间变化是由随机变化的流量conditions.These观察结果表明，在当地年降雨量的差异相关的主要变化，群落结构和功能组成。我们假设，这种关联是有关的连接降雨的水文稳定性，特别是低流量扰动的频率，以及随后的影响河岸植被和时间上可用的生态位流无脊椎动物。我们的工作增加了证据，表明与气候变化相关的降水模式的改变对湖泊动物群产生了广泛的影响。
Climate change is expected to alter rainfall and temperature regimes across the world. The hydrology and riparian zone vegetation of lotic ecosystems are tightly linked to rainfall and a mechanistic understanding of the effects of rainfall on lotic ecosystems is needed to forecast the ecological impacts of climate change. However, it is difficult to isolate rainfall effects from other environmental variables that covary across climates. To address this, we leveraged a unique steep rainfall gradient with few covarying changes in elevation, temperature, and geology to evaluate the effects of rainfall on stream invertebrate communities.We surveyed nine streams in the Texas Gulf Coast Prairie distributed along a 550–1,350 mm/year rainfall gradient. Four sites were classified as drier semi‐arid streams (<750 mm annual rainfall) and five sites were classified as wetter sub‐humid streams (>750 mm annual rainfall). A suite of characteristics including benthic invertebrate community metrics, flow conditions, and water quality variables were assessed monthly for 14 months at each site to relate precipitation regime to stream structure and function.Precipitation regime was observed to be a master explanatory variable. As annual rainfall increased, the flow environment became more stable within seasons and predictable across seasons, influencing spatial structure and temporal variability of invertebrate community composition. Wetter streams were dominated by slower growing taxa without adaptions for desiccation resistance and strong dispersal. Wetter sites displayed seasonal variation in community composition and species richness, whereas temporal variation in communities in drier streams was controlled by stochastic variation in flow conditions.These observations show that differences in local annual rainfall correlated with major changes to community structure and functional composition. We hypothesise that this association is related to the connection of rainfall to hydrological stability, particularly the frequency of low flow disturbances, and the subsequent effects on riparian vegetation and temporally available niches to stream invertebrates. Our work adds to evidence that alterations in precipitation patterns associated with climate change have sweeping impacts on lotic fauna.