西藏羌塘自然保护区藏羚和藏原羚的生境选择

2000年和2001年初夏,在高海拔、低人口密度的阿鲁盆地内对同域分布的藏羚与藏原羚的生境选择进行了研究.以海拔高度、坡度、离山岗距离、坡向以及植被类型作为资源参数,利用Resource Selection Function对藏羚与藏原羚的潜在生态位分化进行检验.研究表明:藏羚和藏原羚对低海拔、相对平地、针茅-非禾本科群落以及北坡的资源选择具有相似性,但对低海拔苔草平地具有强烈的避开;藏原羚对山岗或斜坡生境的利用比藏羚大.以针茅-非禾本科群落为例研究,结果显示斑块植物群落可能是决定生境选择的主要原因.

Habitat selection by sympatric chiru and Tibetan gazelle in the Aru Basin, Chang Tang Nature Reserve, Tibet Autonomous Region, China

Habitat selection was examined between two sympatric ungulate species of the high Tibetan plateau, the chiru (Tibetan antelope) Pantholops hodgsoni and the Tibetan gazelle Procapra picticaudata. The study was conducted in a high elevation area of low human presence during the early part of two summers (2000-2001), within the Aru Basin, Tibet Autonomous Region, China. Potential niche divergence between chiru and Tibetan gazelle was assessed in relation to elevation, slope angle, distance to hills, aspect and vegetation type and resource selection functions were used to attempt to differentiate habitat selection between species. However, habitat selection by the two species was similar in most respects, with both selecting low elevation, relatively flat, northerly facing aspects in Stipa-forb vegetation. Both species strongly avoided Carex vegetation that was present in flat, low elevation sites. Differences between the two species were noted primarily in the gazelle's somewhat greater use of near-hill and hill habitats, possibly related to both food selection and predator avoidance. The results suggest that the scale on which habitat separation occurs between these two species is generally both larger and smaller than that measured here, with plant community patchiness, within the Stipa-forb vegetation type for example, probably a key factor in determining differential habitat selection within the study site.