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Ludwig Bergmann 《Die Naturwissenschaften》1958,45(6):121-123
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Ludwig Trepl 《Die Naturwissenschaften》1992,79(9):386-392
Historically, the biological concept of living organisms from the early 19th century was a precondition for the evolution of the modern concept of the environment. The connection with the hermeneutic concept of the environment qua “landscape” was made through A. v. Humboldt's “physiognomy of plants” and the geographical sciences. At the turn of the 20th century, ecology was established as the “science of communities”. These are primarily considered to have formed through the adaptation of organisms to one another, and, therefore, to an inner environment of a superordinate system. 相似文献
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Monitoring Australian Rangeland Sites Using Landscape Function Indicators and Ground- and Remote-Based Techniques 总被引:5,自引:0,他引:5
John A. Ludwig Gary N. Bastin Robert W. Eager Robert Karfs Pieter Ketner Graham Pearce 《Environmental monitoring and assessment》2000,64(1):167-178
If the goal for managing rangelands is to achieve a balance between production and conservation, then monitoring is essential to detect change and apply corrective action. In some range-land areas of northern Australia, monitoring has detected a tilt in the production-conservation balance towards excessive production. How big is this imbalance? Can it shift back? Robust monitoring is needed to answer these questions. The aim is to know what to monitor, and where. For example, to detect changes caused by livestock on rangeland forage production and soil erosion, indicators linking grazing disturbances to landscape function are needed, that is, indicators that signal how well landscapes are capturing, concentrating, and utilizing scarce water, nutrient, and organic resources. Studies in Australia and the USA document that simple vegetation and soil patch attributes can be measured as indicators of the 'state of health' of landscape function. For example, field and remote sensing-based grazing studies in Australia document that landscapes with a high cover of perennial plant patches function effectively to capture runoff water and nutrients in sediments, whereas landscapes with a low cover of these patches do not — they are dysfunctional — as indicated by large patches of bare soil. Aerial videography is proving to be a robust technique for measuring indicators of landscape function such as small patches of vegetation and the extent of bare soil. These indicators typically have a sigmoidal response to grazing impacts. We illustrate that if these indicators are measured on monitoring sites established near the sigmoidal 'point of inflection’ then small changes in these indicators can be detected. 相似文献