Caves are the best studied aquatic subterranean habitat, but there is a wide variety of these habitats, ranging in depth below the surface and size of the spaces (pore or habitat size). Both factors are important in setting limits to species composition and richness. In addition to caves, among the most important shallow aquatic subterranean habitats are the hyporheal (underflow of rivers and streams), the hypotelminorheal (very superficial drainages with water exiting in seeps), epikarst, and calcrete aquifers. Although it is little studied, both body size and species composition in the different habitats is different. Because of high levels of endemism and difficulty in access, no subterranean habitats are well sampled, even caves. However, there are enough data for robust generalizations about some geographic patterns. Individual hotspot caves are concentrated in the Dinaric region of southern Europe, and overall, tropical regions have fewer obligate aquatic cave dwellers (stygobionts). In all subterranean aquatic habitats, regional diversity is much higher than local diversity, but local diversity (especially single cave diversity) may be a useful predictor of regional species richness. In Europe there is a ridge of high aquatic subterranean species richness basically extending east from the French–Spanish border. Its cause may be either high productivity or that long-term temperature oscillations are at a minimum. With increased collecting and analysis, global and continental trends should become clearer.

中文翻译：

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地下宏观淡水无脊椎动物的栖息地和多样性：主要差距和未来趋势

洞穴是研究得最好的水生地下栖息地，但这些栖息地种类繁多，从地表以下深度和空间大小（孔隙或栖息地大小）不等。这两个因素对于设定物种组成和丰富度的限制都很重要。除了洞穴之外，最重要的浅水地下栖息地包括下流层（河流和溪流的底流）、下层流层（非常浅的排水系统，水从渗流中流出）、表层岩溶和钙质含水层。虽然研究很少，但不同栖息地的体型和物种组成是不同的。由于高度的地方性和难以进入，没有对地下栖息地进行充分采样，即使是洞穴也是如此。但是，有足够的数据可以对某些地理模式进行可靠的概括。个别热点洞穴集中在南欧的第纳尔地区，总体而言，热带地区的专性水生洞穴居民（stygobionts）较少。在所有地下水生栖息地中，区域多样性远高于局部多样性，但局部多样性（尤其是单个洞穴多样性）可能是区域物种丰富度的有用预测指标。在欧洲，有一条水生地下物种丰富度高的脊，基本上从法国-西班牙边界向东延伸。其原因可能是生产率高或长期温度波动最小。随着收集和分析的增加，全球和大陆趋势应该变得更加清晰。在所有地下水生栖息地中，区域多样性远高于局部多样性，但局部多样性（尤其是单个洞穴多样性）可能是区域物种丰富度的有用预测指标。在欧洲，有一条水生地下物种丰富度高的脊，基本上从法国-西班牙边界向东延伸。其原因可能是生产率高或长期温度波动最小。随着收集和分析的增加，全球和大陆趋势应该变得更加清晰。在所有地下水生栖息地中，区域多样性远高于局部多样性，但局部多样性（尤其是单个洞穴多样性）可能是区域物种丰富度的有用预测指标。在欧洲，有一条水生地下物种丰富度高的脊，基本上从法国-西班牙边界向东延伸。其原因可能是生产率高或长期温度波动最小。随着收集和分析的增加，全球和大陆趋势应该变得更加清晰。其原因可能是生产率高或长期温度波动最小。随着收集和分析的增加，全球和大陆趋势应该变得更加清晰。其原因可能是生产率高或长期温度波动最小。随着收集和分析的增加，全球和大陆趋势应该变得更加清晰。