Department of Geography, University of the Balearic Islands, Palma, Balears, Spain.
School of Environmental and Geographical Sciences, University of Nottingham Malaysia Campus, Jalan Broga, Selangor, Malaysia.
Sci Total Environ. 2017 Feb 15;580:1453-1459. doi: 10.1016/j.scitotenv.2016.12.119. Epub 2016 Dec 24.
Here we provide the first evidence of long term reductions in flow in temporary streams on the Mediterranean island of Mallorca and use a simple metric of the degree of water permanence (the number of days with water) to highlight the implications of flow change for aquatic invertebrate diversity. Analysis of a 33year data set for 13 streams on the island yielded evidence of consistent downward trends in water permanence, particularly in spring and summer. Data from 27 relatively undisturbed mountain streams indicate that the diversity of benthic invertebrates in temporary streams across the island is directly related to water permanence. Streams with lower values of water permanence support few species overall and have less abundant invertebrate assemblages; the abundance and species richness of sensitive mayfly, stonefly and caddisfly taxonomic groups is also reduced in streams with lower water permanence. Although developed using spatial data, these flow-invertebrate relationships suggest that future reductions in water permanence may lead to reduced diversity. We argue that the 'number of days with water' is a simple but ecologically-relevant metric of water permanence that can be used effectively to monitor change in threatened temporary streams worldwide.
我们提供了在地中海马略卡岛的临时溪流中长期流量减少的第一个证据，并使用一个简单的水持续时间指标（有水的天数）来突出流量变化对水生无脊椎动物多样性的影响。对该岛 13 条溪流的 33 年数据集进行的分析表明，水持续时间的持续下降趋势明显，尤其是在春季和夏季。来自 27 条相对未受干扰的山区溪流的数据表明，整个岛屿临时溪流底栖无脊椎动物的多样性与水持续时间直接相关。水持续时间值较低的溪流总体上支持的物种较少，无脊椎动物组合也不丰富；在水持续时间较低的溪流中，敏感的蜉蝣、石蝇和石蛾分类群的丰度和物种丰富度也降低。尽管这些流-无脊椎动物关系是使用空间数据开发的，但它们表明未来水持续时间的减少可能导致多样性降低。我们认为，“有水的天数”是水持续时间的一个简单但具有生态相关性的指标，可以有效地用于监测全球受威胁的临时溪流的变化。
