Data and R code used in the article: "Predicting reach-scale macroinvertebrate community changes due to declining flows in an aridland river"

Data and R code used in the article: "Predicting reach-scale macroinvertebrate community changes due to declining flows in an aridland river" Abstract River flow regimes shape the distribution of habitats that structure aquatic macroinvertebrate communities, yet the consequences of declining baseflows for habitat availability and ecosystem function remain poorly understood. We quantified macroinvertebrate community composition, diversity, and abundance across riffle, run, and pool mesohabitats in the Verde River (Arizona, USA) and coupled these data with two-dimensional hydraulic models to predict changes in habitat area under reduced baseflow scenarios. Mesohabitat type explained more variation in community composition than other spatial or temporal factors, with riffles and runs supporting higher macroinvertebrate densities and greater proportions of terrestrially available aquatic insects than pools. Hydraulic modeling predicted nonlinear reductions in fast-flowing habitat as baseflows declined, resulting in disproportionate decreases in aquatic insect production at the reach scale. These findings suggest that gradual reductions in baseflow can substantially alter macroinvertebrate community structure and diminish aquatic-to-terrestrial energy subsidies before flow intermittency occurs. Integrating biological sampling with hydraulic modeling provides a practical framework for identifying ecologically important baseflows and informing environmental flow management in rivers facing increasing hydrologic alteration. In the data folder: Aquatic macroinvertebrate community data, corresponding habitat data, and habitat areas of study sites on the Verde River, AZ USA from 2017 to 2019. Data were collected fall 2017, spring 2018, fall 2018, spring 2019, and fall 2019. Three macroinvertebrate sample replicates were collected from riffles, runs, and pools at our study reaches in Beasley Flats, Childs dispersed camping area, and Sheep Bridge. This is the cleaned version of the data used for analyses. Habitat area data were created using data from Holmquist-Johnson, C. 2020 (Available from https://doi.org/10.5066/P9JZYT2J[L). In the R code folder: R code used for generating tables and figures in the manuscript that depend on the data in the data folder. Verde River Macroinvertebrate sample locations: Coordinates for the sample locations that were used in the study.论文《干旱区河流流量下降引发的河段尺度大型无脊椎动物（macroinvertebrate）群落变化预测》所用的数据与R代码 ## 摘要 河流流量情势决定了塑造水生大型无脊椎动物（aquatic macroinvertebrate）群落的栖息地分布格局，但基流（baseflow）下降对栖息地可获得性及生态系统功能的影响仍未得到充分阐释。本研究对美国亚利桑那州弗德河（Verde River）内浅滩（riffle）、深槽（run）与潭池（pool）这三类中型栖息地中的大型无脊椎动物群落组成、多样性及丰度进行了定量调查，并将这些数据与二维水力学模型（two-dimensional hydraulic model）相结合，以预测基流降低情景下的栖息地面积变化。相较于其他空间或时间因素，中型栖息地类型对群落组成变异的解释度更高；相较于潭池，浅滩与深槽能支撑更高的大型无脊椎动物密度，以及更高比例的可向陆地转移的水生昆虫。水力学模型预测，随着基流下降，急流栖息地面积将呈非线性减少，进而导致河段尺度的水生昆虫生产量出现不成比例的下降。本研究结果表明，在河流断流（flow intermittency）发生前，基流的逐步下降可显著改变大型无脊椎动物群落结构，并削弱水生向陆地的能量补贴。将生物采样与水力学模型相结合，可为识别具有生态重要性的基流阈值，以及为受水文扰动加剧影响的河流制定环境流量管理策略提供实用框架。 ## 数据集文件夹（data folder） 包含2017年至2019年美国亚利桑那州弗德河研究样点的水生大型无脊椎动物群落数据、对应栖息地数据及栖息地面积数据。数据采集时间为2017年秋季、2018年春季、2018年秋季、2019年春季及2019年秋季。研究河段涵盖比斯利平原（Beasley Flats）、蔡兹斯分散露营区（Childs dispersed camping area）与绵羊桥（Sheep Bridge），本研究从各河段的浅滩、深槽与潭池中共采集了3组大型无脊椎动物平行样本。本数据集为用于分析的净化后版本。栖息地面积数据基于Holmquist-Johnson, C. 2020年的数据生成（可从https://doi.org/10.5066/P9JZYT2J获取）。 ## R代码文件夹（R code folder） 包含用于生成论文中表格与图件的R代码，所有代码均依赖于数据集文件夹内的相关数据。 ## 弗德河大型无脊椎动物采样点位 本研究中使用的采样点位坐标信息。