The Study On Evolutional History Of Hainan Islang's Eclogical Environment

The problem of ecological environment is one of the greatest issues in today's world, Chinese ecological environment has also gradually become grave day to day. Some experts assert that Chinese ecological environment is still entirely exacerbating. Ecological environment of Hainan island is also not optimistic, as investigations indicates, the coverage rate of forest in Hainan island was around 90 percent before West Han dynasty, it has been sharply worsening since Ming and Qing dynasty, especially by latest one hundred years the declining speed has immensely accelerated. The coverage rate of natural forest has declined to 25.5 percent till 1956, 18.19 percent in 1964, and 7.2 percent in 1987, in 1999 it was merely 4 percent; During forty-three years from 1956 to 1999, Hainan island has also lost 80 percent of coral reef, meanwhile the number of mangroves decreased from 150,000 mu to 72,000 mu. Moreover, biodiversity has gradually lost, the number of wildlife has increasingly decreases and their distributing areas have steadily shrunk. As aforementioned, the prospect of ecological environment in Hainan is worrying.The study aims to describe and expound process, reasons and ecological consequences of evolvement of Hainan's ecological environment under interference of human activities, and based on the research, bring about new concept to preserve Hainan's ecological environment: creation of Hainan special ecological zone. The spatial scope of the study is Hainan Island, and the main object is the evolvement of plants and animals. Time traces to the beginning of Quaternary Holocene (Hainan Island's first human activity site is Sanya Loubidong, ¹⁴C 10642±207aBP). Large-scale time seems to more possibly interpret cause and effect of evolution of ecological environment.As research perspectives, animal and plant are one of the most fundamental elements of ecological environment. Among biology, human is the centre, animal and plant bear first and direct brunt of environmental effect of human activities, and are important indicator of evolvement of ecological environment. The fastest and largest change of Hainan's ecological environment has been that of animal and plant by latest one hundred years.Being studying object, the evolution of Hainan's ecological environment possesses the most significant scientific value. Firstly, Hainan Island is rare tropical regions in China with...