Spatial and temporal variance of river discharge on Okinawa (Japan): inferring the temporal impact on adjacent coral reefs.
Spatial and temporal variance of river discharge on Okinawa (Japan): inferring the temporal impact on adjacent coral reefs.
复制标题
冲绳（日本）河流流量的时空变化：推断对邻近珊瑚礁的时间影响。
DOI：
10.1016/s0025-326x(01)00040-6
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发表时间：
2001
影响因子：
5.8
通讯作者：
R. van Woesik
中科院分区：
文献类型：
--
作者：
K. West;R. van Woesik
沿海热带地区土地使用的变化和相关的河流排放对珊瑚礁环境构成了全球性威胁。本研究调查了20年来日本冲绳七条河流河口的生物需氧量（BOD 5）和悬浮颗粒物（SPM）的时间变化。我们报告了河流集水区内的人口密度与河流口的平均BOD 5浓度（r2=0.968; p<0.001）和SPM（r2=0.659; p<0.003）之间的强正相关关系。在邻近的一条河流（Hija河，50.2 km 2集水区）的珊瑚礁，我们采用移动窗口分析，以评估最佳的采样策略，阐明从河口的珊瑚组成的过渡边界的河流排放的影响是最小的。冲绳河流的最佳窗口宽度为5个1 m2的样方，间隔超过5 m。这种采样策略清楚地表明，不同的峰值在珊瑚群落组成高达400米的Hija河口，超过这一点，珊瑚组成没有显着差异检测使用相似性分析（ANOSIM）。我们建立了一个简单的扩散模型，将河流的最大排放率、BOD 5和SPM的平均浓度与对珊瑚群落的空间影响联系起来。扩散模型有助于预测有害的土地使用变化预计将导致珊瑚群落的负面变化，是监测珊瑚礁的一个重要工具。
Land-use changes and associated river discharges in coastal tropical regions present a global threat to coral reef environments. This study investigated the temporal variation in biological oxygen demand (BOD5) and suspended particulate matter (SPM) at the mouths of seven rivers on Okinawa Island (Japan) over 20 years. We report strong positive relationships between human population densities within river catchment areas and both average BOD5concentration (r2=0.968; p<0.001) and SPM (r2=0.659; p<0.003) at the mouths of the rivers. At the reef adjacent to one river (Hija River, 50.2 km2catchment area) we applied moving window analysis to assess an optimal sampling strategy for elucidating transitional boundaries in coral composition from the river mouth to a point where the effect of river discharge was minimal. The optimal window width for Okinawan rivers was five 1 m2quadrats spaced over 5 m intervals. This sampling strategy clearly showed dissimilarity spikes in coral community composition up to 400 m from the Hija River mouth, beyond which no significant differences in coral composition were detected using analysis of similarities (ANOSIM). We developed a simple diffusion model linking the rivers' maximum discharge rate, and the average concentration of BOD5and SPM with the spatial impact on the coral communities. The diffusion model can aid in predicting negative shifts in coral communities expected to result from detrimental land-use changes and is an important tool for monitoring coral reefs.