我国幅员辽阔,地势西高东低,起伏较大,由北向南跨越寒温带到热带各种气候带。由于自然条件复杂,全国生物种类繁多,资源丰富。我国人民对自然资源的开发利用历史悠久,尤其是近年科学技术的进步和工农业生产的发展,使自然界面貌的变化无论在深度、广度,还是在速度上都达到了前所 With a vast territory, our country is high in the west and low in the east, with a great ups and downs. It stretches from north to south to all tropical climates in the tropics. Due to the complex natural conditions, the country has a great variety of species and abundant resources. Our people have a long history of exploiting and utilizing natural resources. In particular, in recent years, advances in science and technology and the development of industry and agriculture have made the changes in the outlook of nature reach the forefront in terms of depth, breadth and speed