Riparian buffer zone site-specific factors significance review database

The factor significance review comprised 94 studies. This brought additional studies to those used earlier in the quantitative review (limited to 75 studies documenting mass load reductions) and queried the findings differently. Sediment, nitrate, dissolved and total P were well-studied (≥35 each), total N and runoff volume moderately studied (≥19 studies each) and pesticides, ammonium and coliforms least studied (&lt;19 studies each), with only one study dealing with colloidal P. Evidence comes primarily from warm temperate climate zones, less from snow zone climates and most limited from arid and tropical regions. Studies described effects dominantly in simulated (ie a plot or soil monolith isolated from its landscape context) and created RBZ (a land change to a buffer in a realistic environmental context), with fewer studies in semi-natural riparian zones. There was a mixture of simulated or natural rainfall; only sediment retention evidence draws heavily on studies using artificial plots and/or simulated rain applications. A mixture of temporal scales was used; artificial plot studies tended to be of shorter duration with few isolated rain events, whereas studies of buffers in their landscape context tended to exceed one year. Study spatial scale was dominated more by plot scale investigations with fewer at reach to catchment scales.本因子显著性综述共纳入94项研究，该综述补充了此前定量综述所纳入的研究（该定量综述仅纳入75项记录污染物负荷削减量的研究），并以差异化视角重新审视了相关研究结论。沉积物、硝酸盐、溶解态磷与总磷均得到了充分研究（单指标研究量≥35项），总氮与径流量的研究程度中等（单指标研究量≥19项），而农药、铵态氮与大肠菌群的研究相对匮乏（单指标研究量<19项），其中仅1项研究涉及胶体磷。相关证据主要来自暖温带气候区，少量来自雪带气候区，而干旱区与热带区域的相关证据最为匮乏。现有研究主要针对模拟场景（即脱离景观背景的样地或土壤整段标本）与人工构建的滨岸缓冲带（RBZ，在真实环境背景下通过土地改造形成的缓冲带）开展效应分析，针对半自然河岸带的研究相对较少。降雨设置涵盖模拟降雨与天然降雨两种类型；仅沉积物截留效应的相关证据大量来自采用人工样地和/或模拟降雨实验的研究。研究采用的时间尺度跨度不一：人工样地研究的周期通常较短，仅设置少量单次降雨事件，而针对景观背景下缓冲带的研究周期往往超过一年。研究的空间尺度以样地尺度为主，针对河段至流域尺度的研究相对较少。