Data from: Influence of damming on anuran species richness in riparian areas: a test of the serial discontinuity concept

1. Almost all large rivers worldwide are fragmented by dams, and their impacts have been modelled using the serial discontinuity concept (SDC), a series of predictions regarding responses of key biotic and abiotic variables. 2. We evaluated the effects of damming on anuran communities along a 245-km river corridor by conducting repeated, time-constrained anuran calling surveys at 42 locations along the Broad and Pacolet Rivers in South Carolina, USA. 3. Using a hierarchical Bayesian analysis, we test the biodiversity prediction of the SDC (modified for floodplain rivers) by evaluating anuran occupancy and species diversity relative to dams and degree of urbanized land-use. 4. The mean response of the anuran community indicated that occupancy and species richness were maximized when sites were farther downstream from dams. Sites at the farthest distances downstream of dams (47.5 km) had an estimated ~ 3 more species than those just below dams. Similarly, species-specific occupancy estimates showed a trend of higher occupancy downstream from dams. 5. Synthesis and applications. Using empirical estimation within the context of a 245-km river riparian landscape, our study supports SDC predictions for a meandering river. We demonstrate that with increasing distance downstream from dams, riparian anuran communities have higher species richness. Reduced species richness immediately downstream of dams is likely driven by alterations in flow regime that reduce or eliminate flows which sustain riparian wetlands that serve as anuran breeding habitat. Therefore, to maintain anuran biodiversity, we suggest that flow regulation should be managed to ensure water releases inundate riparian wetlands during amphibian breeding seasons and aseasonal releases, which can displace adults, larvae, and eggs, are avoided. These outcomes could be achieved by emulating pre-dam seasonal discharge data, mirroring discharge of an undammed tributary within the focal watershed, or by basing real-time flow releases on current environmental conditions.

1. 全球绝大多数大型河流均因大坝建设而被碎片化，其生态影响的模拟常采用**序列间断性概念（serial discontinuity concept, SDC）**——该理论提出了一系列关于关键生物与非生物变量响应的预测。2. 本研究以美国南卡罗来纳州布罗德河与帕科莱河沿岸共42个点位为研究对象，通过开展重复定时的无尾两栖类（anuran）鸣唱调查，评估了大坝建设对245公里河流廊道内无尾两栖类群落的影响。3. 本研究采用**分层贝叶斯分析（hierarchical Bayesian analysis）**，通过对比不同点位距大坝的距离以及土地利用的城市化程度，评估无尾两栖类的占有概率与物种多样性，以此检验针对泛滥平原河流修正后的序列间断性概念的生物多样性预测结果。4. 无尾两栖类群落的整体响应结果显示，点位距大坝下游越远，其物种占有概率与物种丰富度越高。距大坝下游最远（47.5公里）的点位，预估物种数比大坝正下方的点位多约3种。类似地，物种特异性占有概率估算结果也呈现出下游点位占有概率更高的趋势。5. 综合与应用。本研究基于245公里河流河岸景观的经验估算结果，证实了序列间断性概念对蜿蜒河流的预测适用性。研究表明，距大坝下游距离越远，河岸带无尾两栖类群落的物种丰富度越高。大坝下游紧邻区域的物种丰富度降低，可能是由于水文情势改变导致维持无尾两栖类繁殖栖息地的河岸湿地所需径流减少甚至消失。因此，为保护无尾两栖类生物多样性，我们建议优化径流调度：一方面需确保在两栖类繁殖季放水淹没河岸湿地，另一方面应避免非季节性放水——此类放水会干扰、驱逐成体、幼体及蛙卵。上述目标可通过以下方式实现：复刻大坝修建前的季节性径流数据、模拟研究流域内未筑坝支流的径流过程，或基于当前环境条件制定实时放水方案。