摘要
博茨瓦纳北部及其毗邻地区分布着世界上最大的非洲象种群(Loxodonta africana),而在100年前,由于过度捕猎,大象的种群数量极为稀少。与此同时,有蹄类由于疾病,种群数量严重下降。大型草食性动物种群数量降低的生态学效应一定是显著的,但我们却知之甚少,不过,目前博茨瓦纳大象种群数量上升之后产生的生态系统变化却引起人们相当大的关注。调查大象种群和其它生态系统组分及过程相互作用的项目"BONIC"就是的基于这种背景。调查结果表明,生态系统随着大象和其它有蹄类的种群数量的增长而发生变化,并且可能向着原先大型草食性动物数量减少之前的方向变化。我们认为人为地改变大象的种群数量没有生态学理由,但控制大象数量有经济和社会道理,而且博茨瓦纳北部大象的分布区可能必须要受到人为限制。
Northern Botswana and adjacent areas,have the world's largest population of African elephant (Loxodonta africana).However,a 100 years ago elephants were rare following excessive hunting.Simultaneously,ungulate populations were severely reduced by decease.The ecological effects of the reduction in large herbivores must have been substantial,but are little known.Today,however,ecosystem changes following the increase in elephant numbers cause considerable concern in Botswana. This was the background for the 'BONIC' project,investigating the interactions between the increasing elephant population and other ecosystem components and processes.Results confirm that the ecosystem is changing following the increase in elephant and ungulate populations,and,presumably,developing towards a situation resembling that before the reduction of large herbivores.We see no ecological reasons to artificially change elephant numbers.There are,however,economic and social reasons to control elephants,and their range in northern Botswana may have to be artificially restricted.
