文档介绍：大连理工大学本科外文翻译绿色景观规划的基础设施 Green Infrastructure for Landscape Planning 大连理工大学 Dalian University of Technology 世纪性的城市设计– 1– Chapter Three Ecosystem functions and health Maintaining biological diversity One of several goals of the following chapters is to show how to maintain or enhance biodiversity at the landscape and municipal level through the use of green infrastructure. Maintaining biodiversity isa challenge, since many species are negatively impacted by human activity or require large territories. In fact, some species require huge territories virtually undisturbed by humans in order to sustain viable populations (Figure ). For example, grizzly bears occupy overlapping home ranges, but their density in the Yellowstone ecosystem is about one bear per 34 square Other species are extremely sensitive to human presence and activity (Figure ). For these species, a country residence in the forest can reduce the presence of these species for as much as600 feet into the 世纪性的城市设计– 2– Figure The hermit thrush (Catharus guttatus) isa forest interior species and highly sensitive to human presence and activity. Its presence is reduced around country residences in the forest for as much as600 feet. In contrast, many species do adapt to the presence of people and the land-use changes they establish. Some species seem to adapt to fragmentation of their habitat. The scarlet tanager isan interior forest bird, but it seems to breed in forest fragments less than 25 acres (10 ha) in size when its preferred interior habitat is Some species, such as crows, are even pletely urbanized and flourish in cities even to the point of ing pests, as is the case with rats and cockroaches. Biological diversity within urban areas can be higher than it is within the surrounding, more natural, ecosystems. This is explained by the many exotic or invasive species that are encouraged or supported by human activities. Exotic plants, whose original habitats are