tailieunhanh - LANDSCAPE ECOLOGY in AGROECOSYSTEMS MANAGEMENT - CHAPTER 2

Phát triển Nông nghiệp và tác động của nó vào chức năng cảnh quan Có vẻ như rõ ràng rằng hoạt động của con người trong việc theo đuổi các nguồn cung cấp thực phẩm an toàn, thoải mái hơn nhà ở, tài nguyên khai thác, vận chuyển người và hàng hóa dễ dàng hơn, và vì vậy đã biến đổi bản chất. Long trước đây, khi mật độ dân số thấp và những người sống trong các nhóm nhỏ cách nhau bởi phạm vi rộng lớn của vùng hoang dã, có thể nhìn thấy tác động về môi trường. | CHAPTER 2 Development of Agriculture and Its Impact on Landscape Functions Lech Ryszkowski and Janusz Jankowiak CONTENTS Introduction Impacts of Agricultural Practices on Landscapes Agricultural Landscape Management for Control of Environmental Threats Prospects of Landscape Management in Programs of Sustainable Development References INTRODUCTION It seems obvious that human activities in pursuit of safe food supplies more comfortable housing resource exploitation easier transport of people and goods and so on have transformed nature. Long ago when population density was low and people lived in small groups separated by vast ranges of wilderness visible impact on environment appeared only locally and degraded sites eventually regenerated after their use was abandoned. Ecologically primeval people differed from other mammals by only one very important skill use of fire which sometimes had remarkable impact on the local landscape. The extinction of the large flightless birds about 50 000 years ago in Australia may be interpreted as the result of habitat destruction by fires ignited by primeval humans Miller et al. 1999 . Restricting living activities to a confined area for long periods of time resulted in landscape transformations evidenced for example by changes in animal communities under the pressure of hunting or gathering. Stiner et al. 1999 showed that the long-term dependence of paleolithic humans on relatively slow-maturing animals such as tortoises or edible mollusks 2002 by CRC Press LLC caused a decline in their size a possible sign of overexploitation. Ecologically such impacts are similar to the broad category of animal influences on habitat such as overgrazing of plant cover by ungulates confined to an island. Improvement of paleolithic technology led to development of tools that increased work efficiency and increased human options to change landscapes. To ensure prosperity people subjugated nature for profits that enabled higher standards of living. A