The changes of community components and their horizontal patterns caused by highway construction in the Longitudinal Range-Gorge Region

Taking Dabao (from Dali City to Baoshan City) and Sixiao (from Simao City to Xiaomengyang Town) highways in the Longitudinal Range-Gorge Region as examples, the changes of community components and their horizontal patterns caused by highway construction were discussed in this article with some mathematic methods, such as contrast analysis, difference analysis and so on. Results indicate: 1) Under the disturbances of highway construction, the predominant species and sub-predominant species’ quantities of arbor and shrub plants on roadsides would decrease to some extent, that of herbaceous plants would increase a lot, and some invading species would appear and distribute. 2) Influenced by highway construction, the distributions of predominant species and sub-predominant species on roadsides would change from uniform or random pattern to aggregate pattern, and their aggregate degrees and diffusivities would increase obviously. 3) The average coverage degrees and heights of Ageratina adenophora and Chromolaena odorata near roads are higher than that far away from roads, but the frequencies of the 2 species have no obvious change on roadsides within 200 m. 4) The positions and landforms of road sections are also important factors influencing community components, the calculated result shows that the influencing intensities on community components caused by Dabao highway are higher than that caused by Sixiao highway, and the compared result of the influencing intensities between the 2 different landforms meet: mountainside > mountaintop.