大沙鼠对肃南县山地荒漠化草原的危害现状调查及成因分析

Investigation and Analysis on Gerbil(Rhombomys opimus)Damages to the Mountainous Desert Steppe in Su'nan County

甘肃省肃南县近年突发大沙鼠(Rhombomys opimus)危害草地。为了掌握大沙鼠危害状况及成因,本研究选择肃南县大沙鼠危害区域,采用了路线调查法和大沙鼠栖息地生境要素调查法。结果显示,大沙鼠在肃南部分山地荒漠化草原危害严重,有明显的爆发性特点。2008-2012年之间,洞群系数、单位面积洞口数和绝对鼠密度几乎从零分别猛增到0.33、3 994洞口/hm2和526只/hm2,使生草面积损失率达40%,造成牧草损失量1 239.15×104 kg。导致大沙鼠成灾的主要原因为干旱的气候、退化封育的草原、大沙鼠适宜的生存环境、小范围防治的局限性以及宽松的生存空间,使大沙鼠种群繁殖力提高、死亡率下降、数量激增,并快速蔓延。

Recently, with the increasing number of gerbil, there was a serious damageto the steppe in Su＇nan county, Gansu province. In order to understand the current situation of gerbil damage and its causes, we conducted a survey with route investigation and habitat investigation in the gerbil damaging areas. The results showed that a serious and sudden gerbil damage was occurred in partial mountainous desert steppe. The hole group coefficient, hole number per unit area, and absolute population density were increased to 0, 33, 3 394 holes/hm^2 and 526 gerbil/hm^2 , respectively. The proportion of damaged grassland areawas 40% ,which resulted in 1 239.15 × 10^4 kg of forage lost. Drought climates, fenced grasslands, suitable habitats, limitation of local control, aswell as enough living space, which led to higher reproduction,lower mortality and high population, and more seriously, this situation is spreading rapidly.