TF第68篇Human_Impacts_on_Biogeography
生物学家通常研究植物和动物物种在不同环境中的分布——他们的生物地理学——努力对物种分布模式进行解释或解释，但如果不考虑人类的影响，这些可能是不正确的。在某些情况下，这些影响可能是偶然的；例如，一些老鼠被无意中从欧洲的船只运到了南太平洋的岛屿上。在其他情况下，物种分布可能已被人类故意修改。南太平洋的波利尼西亚人故意将 kumara（红薯）转移到该地区的岛屿上，为人们提供新的粮食作物。
人类对物种的迁移（以及最近通过国家控制和世界公约对迁移施加的限制）主要是出于经济原因和环境保护。例如，人类将西加云杉树从北美引入苏格兰和英格兰，将其用作木材作物。同样，蒙特利松树于 19 世纪从加利福尼亚引入新西兰，并已成为该国木材生产行业中使用最广泛的树种。马铃薯是从其位于南美洲安第斯山脉高地的故乡运来的，经过改良和发展成为许多品种，并因可以用作粮食作物而运往世界各地。
我们扩大了某些物种的分布范围，因为某些有用的特性使这些物种超出了它们以前已知的范围。例如，柳树具有广泛的根系，可以相对较快地生长，现在在全球多个国家被用于稳定河流边缘作为防洪措施。因此，柳树的分布在很大程度上受到河岸管理中人类使用的影响。
The effects of introduced species can be many and varied and can include effects on the distribution of other species. For example, the North merican gray squirrel was introduced into England and has now largely displaced the native red squirrel. The accidental introduction of organisms to new areas may have major pest implications. The South frican bronze butterfly, the larvae(immature insect forms) of which feed on buds and other parts of geraniums and similar flowers, was accidentally introduced into the alearic Islands via imported geraniums. In its native South frica, the distribution and abundance of the butterfly are affected in part by a native wasp that parasitizes(feeds on) the larvae. In the absence of the parasite wasp on the alearic Islands off the coast of Spain, the butterfly has now spread to mainland. Spain where its rapid spread has been accentuated by trade in garden plants and modern transport. The species has become a major pest due to the lack of natural predator and is now causing great problems for the horticultural industry in Spain. Human-driven changes in the distribution of some species may result in hybridization (interbreeding) with other species and so have a genetic effect. For example, the North merican cord grass was accidentally introduced to the south coast of England in the early nineteenth century. It hybridized with the European cord grass and resulted in the production of a new species, which in this case is also a major pest plant of estuaries in England where it became dominant and extensive.
Information about a species distribution(prior to human modification) may be applied in pest control programs for the introduced species. Studies of the species in its native habitat may yield information about the factors that limit or influence its distribution and population dynamics. That information may then be applied in the development of strategies to contain and control the spread of pest species. For example, information about the role of the parasitic wasp in the ecology of the bronze butterfly may be utilized in the process of finding control strategies for that species on mainland Spain.
1.iologists, who commonly study the distribution of plant and animal species in different environments-their biogeography-strive to develop interpretations or explanation of the patterns of species distribution, but these may be incorrect if the effects of human beings are not taken into consideration. In some cases, these effects may be accidental; for example, some species of rat were unintentionally transported aboard ships from Europe to the islands of the South Pacific. In other cases, species distributions may have been deliberately modified by human beings. The Polynesians in the South Pacific intentionally moved the kumara(sweet potato) to islands in that region to provide the population with a new food crop.
