Terrestrial mesofauna in above- and below-ground habitats: Taylor Valley, Antarctica
Terrestrial mesofauna in above- and below-ground habitats: Taylor Valley, Antarctica
复制标题
地上和地下栖息地的陆地中型动物：南极洲泰勒谷
作者：
B. Simmons;D. Wall;B. Adams;E. Ayres;J. Barrett;R. Virginia
在南极洲的麦克默多干燥山谷地区，地面生产往往仅限于苔藓和藻类，这些藻类出现在季节性可用液态水附近，如短暂的溪流和冰盖的湖泊。与周围的干燥土壤相比，这些关键的过渡带生产力高，土壤动物的种类更多样化，包括轮虫、迟滞动物、线虫和微节肢动物。目前的降温趋势被变暖事件打断，并预测未来气候变暖，预计将影响该区域的水文，从而影响生物多样性和生态系统功能。地上群落暴露在更多变的温度、相对湿度和更大的紫外线辐射中，可能比下面的沉积物更容易受到气候变化的影响，后者受到短期变化的缓冲。在这项研究中，我们比较了生物复杂性(多样性、生产力和栖息地适宜性)不同的冰川河流和湖泊上与苔藓或蓝藻垫子相关的地上和地下群落。与地下沉积物相比，所有土壤动物类群在地上物质中的含量都更丰富。生境适宜性的常见指标(叶绿素a、土壤pH、土壤盐度和土壤氮)在不同植被类型之间没有差异，但在不同地点之间存在显著差异。与无脊椎动物丰度最相关的变量是沉积物盐度、叶绿素a含量和氮浓度。由于气候变化，麦克默多干旱河谷预计将变得更加温暖和潮湿。这可能会增加大多数土壤动物的适宜栖息地的面积，因为液态水的面积可能会增加，并在更长的时间内可用。
In the McMurdo Dry Valleys region of Antarctica, above-ground production is often limited to mosses and algae that occur near seasonally available liquid water such as ephemeral streams and ice-covered lakes. Compared to surrounding dry soils these critical transition zones are highly productive and harbor a more diverse assemblage of soil animals, including rotifers, tardigrades, nematodes and microarthropods. Current cooling trends punctuated by warming events, and predicted future climate warming are expected to affect the hydrology of this region and thereby biodiversity and ecosystem functioning. Above-ground communities are exposed to more variable temperature, relative humidity and greater UV radiation, and may be more vulnerable to climate change than sediments beneath, which are buffered from short-term changes. In this study, we compared above- and below-ground communities associated with either moss or cyanobacterial mats along glacial-fed streams and lakes differing in biological complexity (diversity, productivity and habitat suitability). All groups of soil fauna were more abundant in the above-ground material compared to the sediment beneath. Common indicators of habitat suitability (chlorophyll a, soil pH, soil salinity, and soil nitrogen) did not differ between vegetation types but were significantly different among sites. Variables most correlated with invertebrate abundances were sediment salinity, chlorophyll a content and nitrogen concentration. The McMurdo Dry Valleys are expected to become warmer and wetter as a result of climate change. This will likely increase the area of suitable habitat for most soil animals as areas of liquid water potentially increase and become available for longer periods of time.