Perspective of road ecology development
道路生态学研究进展

Road ecology, representing a new frontier of landscape ecology and just emerging in recent years, has both opportunities and challenges for landscape ecologists. Based on reviewing former research literature,this paper tried to explore a landscape eco network theory in detail to find a framework of eco road network construction. Road networks crossing landscape, yet except for their social and economical benefits, divide natural landscape into pieces, alter landscape spatial patterns, destroy wildlife habitats, interrupt horizontal ecological flows, completely change layer's structures of soils in roadbeds, spread out contaminants and noise through total networks, and therefore disturber or inhibit balance of natural ecosystems. This situation become more serious associated with extending road effect zones, which are usually much greater than the coverage areas of road networks. The structure of road effect zone can be further divided into node effect zone, corridor effect zone, node corridor effect zone, and therefore net effect zone based on a landscape eco network theory. The theory views a landscape ecosystem as a complex network system constructed with physical, economical and social networks. Both road networks and stream networks belong to physical networks for them constructed between natural and artificial networks, designed for carrying ecological flows among functional units of landscape, and still most often observed as major conspicuous objects in landscape. Original stream networks have been constructed by natural ecosystem for carrying ecological flows efficiently,but after road networks interrupt them and create sections with various road stream crossings and effect zones,the functions of stream networks have been partially or totally altered. One of the pilot projects chosen for this study was a process of urban landscape altering agriculture landscape associated with several small natural patches along the section of Jing Chang Highway in Beijing. Supported by Geographic Information System (GIS) and Remote Sensing (RS) techniques, three images of urban landscape structure were identified in the periods of 1975,1985 and 2000. The result demonstrated, after overly of the images, there were only small node effects on both sides of corridor section, Qinghe and Shahe, and almost no visual landscape indicated corridor effect along the section in 1975. Ten years later in 1985, node effects performed much stronger than that of before, especially on Qinghe site for it is closer to the central area of Beijing, and on the other hand several urban landscape patches connected with the corridor section indicated an increasing corridor effects. Those corridor effects could be observed from continuous growing urban patches along the section and almost connected each other in 2000. Therefore, this trend may lead to the result of complete dividing agriculture landscape in the study area. This process was further explained with several hypothesis