Oribatid (Acari: Oribatida) diversity in natural and altered open arid ecosystems of South-Eastern Caucasus

Data was collected in arid and semi-arid areas of Kakheti Region (south western Georgia), which is characterized by low annual precipitation (600mm on average), cold winters and hot, dry summers. Field sampling was conducted in November 2017, and April and June of 2018 in three geographic units – Shiraki and Eldari valleysand Gareji semi-desert. These territories are (or have been) used for intensive agriculture like tillage and grazing for a long historical time. Only small patches (usually hardly accessible areas of the region) are preserved more or less in a natural condition either with domination of wormwood or saline semi-deserts. Semi-desert ecosystems are generally distributed on 150-700 m altitudes, while dry grassland vegetation can be found at foothills of 300-700 m a.s.l. (Sakhokia 1958). Oribatid mite communities were studied in three types of ecosystems with different disturbance class: (1) Arable lands with severe (ASE) and moderate (AME) erosion; (2) Pasture lands with heavy (PH) and moderate (PM) overgrazing; (3) Natural grasslands with severe (NSE), medium (NME) and no (N) erosion. For each disturbance class (7 in total) nested in three geographic unit (Shiraki, Eldari and Gareji) three sites of 50 m2 were established, and in each site three soil samples of 10cm3 volume were taken. In total 63 sites were investigated and 189 soil samples were collected three times seasonally.

本数据集采集于格鲁吉亚西南部卡赫季地区（Kakheti Region）的干旱与半干旱区域，该区域年均降水量约600毫米，冬季寒冷，夏季炎热干燥。野外采样工作于2017年11月及2018年4月、6月开展，覆盖三个地理单元：希拉基河谷（Shiraki Valley）、埃尔达里河谷（Eldari Valley）与加雷吉半荒漠（Gareji Semi-desert）。该区域历史上长期被用于集约化农业活动，包括耕作与放牧；仅存少量斑块状区域（多为区域内难以抵达的地段）大致保留自然原生状态，植被以苦艾占优或为盐生半荒漠生境。半荒漠生态系统主要分布于海拔150-700米区间，而干燥草原植被则见于海拔300-700米的山麓地带（a.s.l., Sakhokia 1958）。本研究针对三类不同干扰等级（disturbance class）的生态系统中的甲螨（Oribatid mite）群落展开调查：（1）存在严重侵蚀（ASE）与中度侵蚀（AME）的耕地；（2）存在重度过度放牧（PH）与中度过度放牧（PM）的牧草地；（3）存在严重侵蚀（NSE）、中度侵蚀（NME）以及无侵蚀（N）的天然草原。在嵌套于三个地理单元（希拉基、埃尔达里、加雷吉）的全部7个干扰等级中，每个等级均设置3个面积为50平方米的样地；每个样地内采集3个体积为10立方厘米的土壤样本。本研究共调查63个样地，分三次季节性采样，累计获取土壤样本189份。