首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   5篇
  免费   0篇
地质学   1篇
综合类   1篇
自然地理   3篇
  2015年   1篇
  2006年   2篇
  1997年   1篇
  1994年   1篇
排序方式: 共有5条查询结果,搜索用时 15 毫秒
1
1.
本文论述了1992年采自浙江开化的一件羚羊头骨化石。标本经记述对比研究后,认为它代表了GazelleBlaimville的一个新种,命名为开化羚羊(新种)Gazellekaihuaensissp.nov,时代也属于晚更新世。尚系浙江首次发现,这对羚羊的分布范围及其古地理、古环境等方面的研究具有一定的意义。  相似文献   
2.
Perennial plants eaten by mountain gazelle (Gazella gazella) and Nubian ibex (Capra ibex nubiana) were examined during the 1994 growing season (May and June) in the Ibex Reserve, Saudi Arabia. Individual plants were assigned a browse rating based on extent of vegetative tissue removal. Gazelles and ibex were found to have a diverse diet, but were primarily browsers of woody plants.  相似文献   
3.
We report the impacts of human visits at a waterhole used by mountain gazelles, Gazella gazella, and Nubian ibex, Capra ibex nubiana, in the Ibex Reserve of Saudi Arabia. Our hypothesis was that the species that normally used the waterhole during the day, the typical period of human visits, would be negatively affected. The results did not support our hypothesis, as both the diurnal mountain gazelles and partly nocturnal Nubian ibex avoided the waterhole within 6 h after human visits. We found no significant difference of waterhole use by Nubian ibex and mountain gazelles within the period of 6–12 h or 12–24 h after human visits. Given the high conservation concern of these species and the rarity of waterholes, we suggest that human visits continue to be regulated by allowing visits on non-consecutive days to give the ungulates opportunities to drink, especially during the summer and droughts when heat stresses are higher, animals are less tolerant of water deprivation, and there are less alternative waterholes.  相似文献   
4.
文章记述了甘肃临夏盆地晚中新世杨家山动物群的瞪羚(Gazella)化石,将临夏材料归为保德瞪羚(Gazella paotehensis)、高氏瞪羚相似种(G.cf.gaudryi)和瞪羚未定种(G.sp.).G.paotehensis为有效种,与G.gaudryi区别在于G.paotehensis两角心分散度大,表面发育较深纵沟;与G.dorcadoides区别在于G.paotehensis角心向后外方伸出角度较高,侧视倾斜度小,脑颅部从额项缝开始呈弧形向后下方弯曲.依据临夏的瞪羚化石组合推测杨家山动物群的生活环境可能为温带开阔草原,有灌木丛为典型食叶者食用.依据脑颅轮廓,G.paotehensis应归入短头型,验证了G.paotehensis可能是G.blacki祖先的观点.  相似文献   
5.
新疆哈密盆地初冬鹅喉羚的地理分布与种群数量   总被引:8,自引:0,他引:8  
高行宜  姚军 《干旱区地理》2006,29(2):213-218
2004年11月2日至25日,采用截线抽样法,对新疆哈密盆地鹅喉羚的地理分布和种群数量进行了考察。结果证实:鹅喉羚广泛分布于哈密盆地及其周边各类地理环境中,并可分为高、中、低三级密度区,各密度区的栖息密度和种群数量分别为,3.33±0.24头/km2和12 431±896头,0.95±0.055头/km2和21 651±1254头,0.056±0.042头/km2和3 026±2 270头,资源总量为37 108±4 420头。并讨论了过牧对草场的破坏和鹅喉羚生存面临的环境压力,提出了改良家畜饲养模式,以草定畜,恢复天然植被,在高密度区和中等密度区计划猎取鹅喉羚,控制种群数量,合理利用的建议。  相似文献   
1
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号