生物學(xué)家通常研究植物和動(dòng)物物種在不同環(huán)境中的分布——他們的生物地理學(xué)——努力對(duì)物種分布模式進(jìn)行解釋或解釋，但如果不考慮人類的影響，這些可能是不正確的。在某些情況下，這些影響可能是偶然的；例如，一些老鼠被無(wú)意中從歐洲的船只運(yùn)到了南太平洋的島嶼上。在其他情況下，物種分布可能已被人類故意修改。南太平洋的波利尼西亞人故意將 kumara（紅薯）轉(zhuǎn)移到該地區(qū)的島嶼上，為人們提供新的糧食作物。

???????人類對(duì)物種的遷移（以及最近通過(guò)國(guó)家控制和世界公約對(duì)遷移施加的限制）主要是出于經(jīng)濟(jì)原因和環(huán)境保護(hù)。例如，人類將西加云杉樹(shù)從北美引入蘇格蘭和英格蘭，將其用作木材作物。同樣，蒙特利松樹(shù)于 19 世紀(jì)從加利福尼亞引入新西蘭，并已成為該國(guó)木材生產(chǎn)行業(yè)中使用最廣泛的樹(shù)種。馬鈴薯是從其位于南美洲安第斯山脈高地的故鄉(xiāng)運(yùn)來(lái)的，經(jīng)過(guò)改良和發(fā)展成為許多品種，并因可以用作糧食作物而運(yùn)往世界各地。

???????我們擴(kuò)大了某些物種的分布范圍，因?yàn)槟承┯杏玫奶匦允惯@些物種超出了它們以前已知的范圍。例如，柳樹(shù)具有廣泛的根系，可以相對(duì)較快地生長(zhǎng)，現(xiàn)在在全球多個(gè)國(guó)家被用于穩(wěn)定河流邊緣作為防洪措施。因此，柳樹(shù)的分布在很大程度上受到河岸管理中人類使用的影響。

???????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.?