Abstract

Miocene, Pliocene and Pleistocene changes to the geomorphology, climate and vegetation of southern Africa are considered responsible for radical differences between southwest and northeast dung beetle assemblages (Coleoptera: Scarabaeidae: Scarabaeinae) leading to current endemism in Namibia, Botswana and South Africa. This bias is supported by distributional analysis of 437 species across vegetation regions and 2° × 2° squares of latitude and longitude using non-metric multidimensional scaling (NMDS) and minimum spanning trees (MST). The ordinal values for six NMDS dimensions showed significant correlations with annual rainfall, annual temperature, rainfall seasonality and altitude. Significant climatic differences were also shown between six regional centres defined and modelled for the subcontinent: winter/bimodal rainfall, southwest arid, southeast highlands, savanna, sandy savanna and east coast. Twenty-one, principal, subregional centres defined from further NMDS and MST analyses of regional data showed significant intra-regional differences in climatic attributes although published data suggest that soil, vegetation and dung type associations were frequent additional influences. Species showing the smallest ranges were centred primarily around the coast and bordering escarpments, which coincide with regions and subregions showing unique environmental conditions characterized by many endemic genera and species. Published land use data indicate that large parts of these regions are highly transformed or degraded, so that some species are facing strong current threats. Furthermore, published global climatic change data suggest that many endemic species could be further threatened, especially to the southwest where the late Cenozoic trend to unique climatic and environmental conditions could, potentially, be reversed in the future.

中文翻译：

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南部非洲的甲虫保护生物地理学：气候变化的当前挑战和潜在影响

摘要

南部非洲的地貌，气候和植被的中新世，上新世和更新世的变化被认为是西南和东北甲虫组合（鞘翅目：Scarabaeidae：Scarabaeinae）之间根本不同的原因，这导致了纳米比亚，博茨瓦纳和南非目前的特有性。使用非度量多维标度（NMDS）和最小生成树（MST）对437种植物在植被区域和2°×2°纬度和经度平方上的分布进行分析，可以支持这种偏差。六个NMDS维度的序数值与年降雨量，年温度，降雨季节和高度显着相关。在为该次大陆定义和建模的六个区域中心之间也显示出显着的气候差异：冬季/双峰降雨，西南干旱，东南高地，热带稀树草原，沙质稀树草原和东海岸。通过进一步的NMDS和MST区域数据分析确定的二十一个主要子区域中心显示了气候属性的区域内显着差异，尽管已发表的数据表明土壤，植被和粪便类型的关联是频繁的附加影响。显示最小范围的物种主要集中在沿海和毗邻的悬崖上，这与具有独特的环境条件的区域和次区域一致，这些环境条件具有许多特有的属和物种。公布的土地利用数据表明，这些地区的大部分地区都已高度转化或退化，因此某些物种正面临强大的当前威胁。此外，已发布的全球气候变化数据表明，许多特有物种可能会受到进一步威胁，