Data from: A before-and-after assessment of patch-burn grazing and riparian fencing along headwater streams

1. Fire and grazing are common in grasslands worldwide to maintain grass cover and cattle production. The effects of fire, cattle grazing, and riparian fencing efficacy on prairie stream ecology are not well characterized at catchment scales.
2. We examined alterations to stream water quality and biology from patch-burn grazing in tallgrass prairie during a five-year, replicated, catchment scale experiment that used a Before–After Control–Impact (BACI) design and was analysed by mixed-effects models. Treatments included two patch-burned control catchments (fire but no grazers) and patch-burn grazing in two riparian fenced and two unfenced catchments. We assessed the effectiveness of riparian fencing for mitigating potential water quality impacts by monitoring water quality and use of riparian by cattle via Global Positioning System.
3. Riparian fences effectively excluded cattle, while in unfenced pastures cattle aggregated along streams 10–20% of the grazing season.
4. After initiation of patch-burn grazing, we detected large increases in some nutrients, Escherichia coli, algal biomass, primary productivity, and community respiration in all catchments with patch-burn grazing. Some water quality variables, such as E. coli concentrations, recovered quickly which indicated resiliency.
5. Riparian fencing moderately reduced the impacts to stream variables, indicating either overland flow or subsurface flow allowed nutrients and bacteria to enter the streams.
6. Synthesis and applications. Patch-burn grazing is a measurable disturbance that can alter the ecological condition of streams. Riparian fencing lessened the degree of impact, yet some water quality variables still exceeded regional reference conditions. Managers will need to assess the costs of riparian fencing compared to the moderate benefits that fencing provides to water quality.

1. 火烧与放牧是全球草原生态系统中维持草地覆盖、保障畜牧生产的常见管理手段。目前在流域（catchment）尺度上，火烧、家畜放牧以及河岸围栏（riparian fencing）的效能对草原溪流生态的影响尚未得到充分阐明。
2. 本研究依托一项为期5年、设置重复的流域尺度野外控制实验，采用前-后对照-影响（Before–After Control–Impact, BACI）设计，并通过混合效应模型（mixed-effects models）进行数据分析，探究了高草草原（tallgrass prairie）斑块火烧放牧（patch-burn grazing）对溪流水质与水生生物的影响。实验设置包括2个仅实施斑块火烧的对照流域（有火烧但无家畜放牧），以及2个设置河岸围栏和2个未设置河岸围栏的斑块火烧放牧流域。本研究通过监测水质，并借助全球定位系统（Global Positioning System, GPS）追踪家畜对河岸带的利用情况，以评估河岸围栏缓解潜在水质影响的效能。
3. 河岸围栏可有效阻隔家畜进入溪流区域，而在未设置围栏的牧场中，放牧季内有10%~20%的时间家畜会聚集在溪流周边。
4. 在斑块火烧放牧实施后，所有实施该管理措施的流域中，部分营养盐、大肠杆菌（Escherichia coli, E. coli）、藻类生物量、初级生产力以及群落呼吸水平均出现显著升高。部分水质指标（如大肠杆菌浓度）可快速恢复，这表明溪流生态系统具备一定的恢复力。
5. 河岸围栏可适度降低该管理措施对溪流相关指标的影响，这表明营养盐与细菌可通过地表径流或地下径流进入溪流。
6. 研究总结与应用展望：斑块火烧放牧属于可量化的干扰因素，能够改变溪流的生态状态。河岸围栏可降低该干扰的影响程度，但部分水质指标仍超过区域参照标准。管理者需要权衡河岸围栏的建设成本与该措施对水质带来的适度增益。