The Research On Plants' Protection Function On The Earthen Sites Of Han Yangling

Earthen sites are earth based historical sites,which are very rare and important heritage remaings.There have much developmemt on the conservation of earthern sites in the dried areas;however,the consiveration of earthen sites in humid area needs to be further studied.Based on vast field research,it has shown that earthen sites with plant protected are preserved relatively better.It would be very meaningful to study the conservation of earthen site with the application of vegetation slope protection techniques and soil erosion controlling techniques.The yearly amount of precipitation in Han Yangling is 563 mm.The types of the earthen sites include Mausoleum,walls and sha buried pits,which are the very typical earthen sites in semi-humid region.This thesis will mainly study on Hang Yangling earthen sites.Firstly the study will select the plants that fit for the conservation for earthen sites based on literature research and field investigation on vegetation communities and soil nutrients.Secondly the thesis will evaluate different plants' conservation effects on earthen sites by simulatation experienments.Lastly,the article will evaluate outward appearance for earthen historical sites,which will be of guidance of applying conservation to make it both functional and easthetically beautiful.The outcome of the research will be listed as the following.1)The bio conservation method has been applied into the historical sites of Mao ling,Du Ling,Changan city sites,Luoyang city sites,and so on.And it has good results.The survival rate of the plants are not very high,therefore,more reseach on selection of plants needs to be done.2)The thesis has made detail investigation on the Han Yangling earthen site.There are 47 species in total consists of 36 gnera and 20 families,in which contains a big section of herbs.By using the dominance analysis method,the advantage spicies are Heteropappus altaicus,Roegneria ciliaris,Poa annua,Stipa capillata and Artemisia scoparia.The main kind of shrub is Prinsepia uniflora,while the trees are Ziziphus jujube and Broussonetia papyrifera.The average vegetation coverage is 60-85%,under which the sites remain well.3)The result of soil nutrients tests shows that the soil is strong basic in Han Yangling district,which PH is between 8.29 and 9.43.The content of K is very high,while P,N and organic matters are lacking.Nutrient materials in shrub communities are more than them in herb communities.4)The simulation of raining experiements has shown that graminaceous plants with the height shorter than 40 cm,diameter smaller than 0.5mm,such as Poa annua,Cynodon dactylon;and compositae plants with the height taller than 70cm,diameter between 1.3 and 3mm,such as Artemisia dubia,Artemisia argyi,are more resistent to rain erosion.5)The conservation method should be in accordance with the appearance of historical sites.The selection of the plants for conservation should not only meed the needs for visitor's aethestic understanding,but complies with the site's historical meaning.