Research On The Quantitative Change And Its Driving Forces Of Forests In Beijing City

Urban forests have been a important index to evaluate a city civilization development and sustainable development. Takes Beijing City as a study area to study the quantitative change and its driving force of forests. The main research ways used in this paper are the methods combing the qualitative analysis and the quantitative study, combing the static analysis and the dynamic analysis, and combing RS investigation and the indoor analysis. This paper studies the changes and its regional types of forests quantity in Beijing City. The development trend of quantitative change of forests in Beijing City is predicted through establishing cubic equation.The driving forces and the function of influence factors of quantitative change of forests in Beijing City is analyzed. The main research results in this paper as follows: The quantity of forests in Beijing City has changed very fast in recent ten years. From 1994 to 2004, the forests area in Beijing City increase from 893159hm2 to 1030686 hm2. The net increase area of forests are 137526.7 hm2. The average annual increase rate is 15.40%. Forest coverage rate net increase 7.59. The average annual increase rate is 0.759%. Trees coverage rate net increase 13.73. The average annual increase rate is 1.37%. Forest stock increase 154619.2 hm2. It increase 56.6%. In the future the quantity of forests in Beijing City will increase more. Trees coverage rate will reach our expecting target.The quantitative change of forests in Beijing City had clearly time and space features. In the time of forests quantity change, the fast increase of forests area in Beijing City is the time from 1999 to 2004, which is fast than the time from 1994 to 1999. In the space of forests quantity change, the different towns and districts had different speed and directions of forests quantitative change in Beijing City. Firstly four city zones reduce fast. Then the zones whose industry are forest and herd products are increase fast. Thirdly the zones whose industry are farming and herd...