In dry areas, natural and artificial ponds experience frequent water level fluctuation, affecting conditions for some aquatic and amphibiotic taxa. Water beetles, bugs, and dragonflies make up much of pond diversity, and are responsive to changes in environmental conditions. Using a drought-prone pondscape within the Greater Cape Floristic Region biodiversity hotspot, we determine (1) the relative extent to which species richness, abundance, and composition are affected by pond water level fluctuation, (2) the effects of environmental variables and vegetation characteristics relative to fluctuating water levels, and (3) make recommendations to improve pondscape conservation. We found that the degree of fluctuation had a significant effect on beetle species richness, but had no significant effect on the other focal taxa. Water temperature, pH, and conductivity, and vegetation cover and composition were drivers of aquatic insect species richness, abundances, and assemblage structures. Habitat heterogeneity supported rich aquatic insect assemblages. We recommend that a range of ponds with various degrees of water level fluctuation should be maintained, along with naturally diverse marginal vegetation. Such a dynamic pondscape can contribute greatly towards maintenance of local and regional aquatic insect diversity in drought-prone regions and should be considered as a main focus in conservation efforts.

中文翻译：

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易旱的地中海型气候中池塘水位的波动和水生昆虫的持久性

在干旱地区，天然和人工池塘的水位经常波动，影响一些水生和两栖类群的条件。水甲虫、臭虫和蜻蜓构成了池塘多样性的大部分，并对环境条件的变化做出了反应。使用大开普省植物区生物多样性热点内易干旱的池塘景观，我们确定 (1) 物种丰富度、丰度和组成受池塘水位波动影响的相对程度，(2) 环境变量和植被的影响与波动的水位相关的特征，以及 (3) 提出改善池塘景观保护的建议。我们发现波动程度对甲虫物种丰富度有显着影响，但对其他焦点分类群没有显着影响。水温、酸碱度、和电导率、植被覆盖和组成是水生昆虫物种丰富度、丰度和组合结构的驱动因素。栖息地异质性支持丰富的水生昆虫组合。我们建议应保持一系列水位波动程度不同的池塘，以及自然多样化的边缘植被。这种动态的池塘景观可以极大地促进干旱多发地区当地和区域水生昆虫多样性的维护，应被视为保护工作的主要重点。我们建议应保持一系列水位波动程度不同的池塘，以及自然多样化的边缘植被。这种动态的池塘景观可以极大地促进干旱多发地区当地和区域水生昆虫多样性的维护，应被视为保护工作的主要重点。我们建议应保持一系列水位波动程度不同的池塘，以及自然多样化的边缘植被。这种动态的池塘景观可以极大地促进干旱多发地区当地和区域水生昆虫多样性的维护，应被视为保护工作的主要重点。