Macroinvertebrate and ecosystem function data from replicated in-stream experiments in Tasmanian streams (2021–2023)

This dataset is from an experiment testing stream community responses to catchment conversion to agriculture and short-term flow changes.
We used a multiple before–after control–impact (mBACI) design across 8 Tasmanian streams (4 agricultural, 4 forested) during late summers of 2021–2023. Each stream contained three reaches (control, low flow, high flow). Flow was manipulated using temporary semi-porous weirs to create treatment conditions. Macroinvertebrate, physicochemical, and ecosystem function measurements were taken before, during, and after a disturbance (median 24.5 days, range 19–30), followed by a recovery (median 85 days, range 84–92). The sampling sequence was: Sample 1: pre-disturbance (baseline, all reaches), Samples 2–3: weekly during disturbance (weirs in place), Samples 4–6: monthly during recovery (post-weir removal). Macroinvertebrates were sampled with 0.25 m² box sampler; rocks scrubbed, fine material disturbed into 200 µm mesh net; preserved in 70% ethanol and identified to lowest practicable taxonomic level. Physicochemical variables were spot measures of temperature, pH, conductivity, dissolved oxygen (Hach HQ40d), and flow (Schiltknecht MiniAir 2); continuous temperature logging at controls using HOBO loggers and Derwent Estuary Program data.
Ecosystem functions were leaf decomposition (mesh bags with ~5 g dried green Eucalyptus viminalis leaves, 45 per site (3 × 15 per treatment/control), retrieved at 5 intervals; leaves dried (40 °C, ~48 h) and weighed; negative controls corrected for transport/set-up loss); cellulose decomposition (45 unbleached cotton strips (65 × 35 mm; EMPA, Switzerland) per site, on submerged ropes, retrieved at 5 intervals; tensile strength loss measured with Salter ElectroSamson scales); algal accrual (45 unglazed ceramic tiles (25 × 25 mm) per site, retrieved at 5 intervals; chlorophyll a extracted with 90% ethanol and quantified spectrophotometrically).

本数据集源自一项实验，旨在探究溪流群落对集水区转为农业用地以及短期径流变化的响应。
研究采用多时段对照影响（multiple before–after control–impact, mBACI）实验设计，于2021年至2023年的夏末阶段，在塔斯马尼亚州的8条溪流中开展实验（其中4条溪流周边为农业用地，4条为森林流域）。每条溪流设置3个河段：对照河段、低流量河段与高流量河段。通过临时半透水堰对流量进行人工调控，以构建实验处理条件。
分别在扰动前、扰动期间以及扰动后（扰动持续时长中位数为24.5天，范围为19~30天）开展大型无脊椎动物、理化参数以及生态系统功能的测定，随后进入恢复监测阶段（恢复时长中位数为85天，范围为84~92天）。采样序列如下：样本1：扰动前（基线采样，覆盖所有河段）；样本2~3：扰动期间每周采样（堰体布设阶段）；样本4~6：恢复期间每月采样（堰体移除后）。
大型无脊椎动物采样采用0.25 m²的箱式采样器：刷洗岩石表面，将细颗粒物质扰动至200 µm孔径的网具中收集样品，以70%乙醇固定样品，并鉴定至可行的最低分类学层级。
理化参数测定包括：温度、pH、电导率、溶解氧（使用Hach HQ40d检测仪）以及流量（使用Schiltknecht MiniAir 2设备）的现场单点测定；对照河段采用HOBO记录仪进行连续温度记录，同时辅以德文特河口项目（Derwent Estuary Program）的监测数据。
生态系统功能测定包含以下三项：
1. 叶片分解实验：将约5 g干燥的亮绿桉（Eucalyptus viminalis）叶片装入网袋，每个样点设置45个网袋（每个处理/对照组设置3组，每组15个），分5个时段回收样品；将回收的叶片经40℃烘干约48小时后称重，设置阴性对照以校正转运与布设过程中的样品损耗。
2. 纤维素分解实验：每个样点设置45条未漂白棉条（规格65×35 mm，产自瑞士EMPA公司），将棉条固定于水下绳索上，分5个时段回收；使用Salter ElectroSamson天平测定棉条的拉伸强度损失。
3. 藻类附着量测定：每个样点设置45块无釉瓷砖（规格25×25 mm），分5个时段回收；采用90%乙醇提取样品中的叶绿素a，通过分光光度法进行定量分析。