Table_3_Biodiversity Patterns of Macroinvertebrate Assemblages in Natural and Artificial Lentic Waters on an Oceanic Island.docx

The Azorean islands have been historically affected by human activities, mainly due to the combined effects of habitat degradation and fragmentation, and the introduction of exotic species. We here aim to analyze the role of environmental characteristics and spatial descriptors in supporting regional biodiversity of macroinvertebrates by considering natural ponds and artificial tanks. After the monthly variation of macroinvertebrate assemblages was assessed in three temporary and two permanent ponds in the Azorean island of Terceira during a complete inundation-desiccation annual cycle, the assemblage differences of 12 ponds (three temporary and nine permanent ponds) and 8 closely-located artificial tanks were analyzed across a range of landscape disturbances. Macroinvertebrate assemblages were found to differ according to hydroperiod and sampled months. Although the former explained the highest variance, macroinvertebrate differentiation by hydroperiod was also dependent on the study month. Our results also revealed a consistent monthly pattern of species replacement. However, the contribution of nestedness to the macroinvertebrate β-diversity was notable when temporary ponds were close to desiccation, probably indicating a deterministic loss of species due to the impoverished water conditions of the ponds facing desiccation. When the macroinvertebrate assemblages were analyzed in relation to physico-chemical variations and spatial descriptors, the artificial tanks were not clearly segregated from the natural ponds, and only differentiated by pH differences. In contrast, those natural ponds exhibiting high concentrations of total phosphorous (likely signs of anthropization) also discriminated the ordination of ponds in a distance-based redundancy analysis, and showed impoverished assemblages in comparison with well-preserved ponds. The macroinvertebrate assemblages of the natural ponds showed a significant spatial pattern, but this spatial influence was not significant when tanks and ponds were considered together. Our results suggest that tanks may act as possible reservoirs of biodiversity during the desiccation period of temporary ponds, but are unable to establish successful populations. These fishless permanent tanks can complement the conservation of a biodiversity that is largely maintained by the pristine high-altitude natural ponds. The establishment of a guideline for conservation management that also considers the artificial tanks is necessary to benefit the local and regional Azorean macroinvertebrate diversity.

亚速尔群岛历来深受人类活动的影响，主要由于栖息地退化和破碎化以及外来物种的引入所造成的综合效应。本研究旨在通过考虑自然池塘和人工池塘，分析环境特征和空间描述符在支持区域大型无脊椎动物生物多样性方面的作用。在亚速尔群岛特塞拉岛上的三个临时池塘和两个永久池塘中，对大型无脊椎动物群落的月度变化进行了评估，并在此完整的水淹-干燥年度周期内，分析了12个池塘（三个临时池塘和九个永久池塘）以及8个邻近的人工池塘在不同景观干扰范围内的群落差异。研究发现，大型无脊椎动物群落根据水文周期和采样月份存在差异，尽管水文周期解释了最大的方差，但大型无脊椎动物按水文周期进行区分也依赖于研究月份。研究还揭示了一种一致的物种替代月度模式。然而，当临时池塘临近干涸时，嵌套性对大型无脊椎动物β多样性的贡献显著，这或许表明了由于面临干涸的池塘水质贫瘠，物种因确定性损失而减少。在将大型无脊椎动物群落与物理化学变化和空间描述符相关联时，人工池塘并未与自然池塘明显分离，仅通过pH差异进行区分。相反，那些总磷含量高（可能是人类活动迹象）的自然池塘在基于距离的冗余分析中区分了池塘的排序，并且与保存完好的池塘相比，显示出生物群落的贫瘠。自然池塘中的大型无脊椎动物群落显示出显著的时空模式，但当将池塘和池塘一起考虑时，这种空间影响并不显著。我们的结果表明，在临时池塘的干涸期间，池塘可能作为生物多样性的潜在储存库，但无法建立成功的种群。这些无鱼的永久池塘可以补充保护由原始高海拔自然池塘维持的大多数生物多样性。有必要制定一项考虑人工池塘的 Conservation Management 指南，以造福当地和区域的亚速尔大型无脊椎动物多样性。