| Southwest China, including three provinces of Yunnan, Guizhou andGuangxi, is the largest karst concentrative area in the world. In this area, largepopulation, low land productivity and weak economic power, result in ruiningforests for farmlands objectively. In karst areas, topsoil is so thin that it willeasily be washed away if the vegetations are ruined, and it causes the decline ofland productivity and the existence of bare rocks, which has formed rockydesertification. Rocky desertification has made land productivity descend,environmental capacity decline and water resources decrease, so that humancan't live in such areas. So, the restoration and reconstruction of vegetations inrocky desertification areas are the first in the integrated control work. This paperattaches importance on the ecological control techniques and, according tocharacteristics of ecological system and the effects of ecology, economy andsociety, combines ecological construction with anti-poverty measures, in orderto restore the vegetations and ecological system in rocky desertification areasand build up a demonstration area with strong demonstrative effect, for thedevelopments of society and economy and the ecological balance in karst areas. With Huajiang area as the studying object and from theory foundation,restoration technique and demonstrative research, this paper studies controlmodels of agriculture-forestry industry in the serious and typical areas. Based onthe theories of ecological economics, restoration ecology, landscape ecology,sustainable development, anti-poverty and regional system in human-landrelationship and combined with the last policies and market changes, the paperstudies the ecological integrated control model in serious and typical rockydesertification. On the basis of the summary of experiences and techniquesbefore and through fieldwork in the sample plots, this paper studies structureand function of artificial woods in the areas with different rocky desertificationranks and explores the ecological control model and forestation techniques toestablish the demonstration area in subtropical karst areas which is fit for localconditions. There are 24 plots with every standard area 20×10 m2 in the experiment, ofwhich there are 3 strong-rank plots, 9 medium-rank plots, 3 light-rank plots, 8potential-rank plots and 1 original plot. In addition, selecting these plots hasconsidered local effect factors and their location combination, so these plots canstand for the whole studying area. Through the survey and observation ofbio-diversity and microclimate, the paper points out the concrete structure andfunction changes of artificial woods in rocky desertification areas, proves thefeasibility of Huajiang model through the experiment and explores the plantingtechniques of artificial woods in the demonstration area. Firstly it establishes the differentiated standards of rocky desertificationrating with a large scale in the demonstration area. The rocky desertificationrating is based on the characteristics of TM images, the remote sensing datasource, and fieldwork, with the rates of vegetation cover and bare rock as thedifferentiated standards of remote sensing images. The rocky desertification inHuajiang is divided into three ranks, that is, strong rank, medium rank and lightrank. In strong rank, vegetation cover rate is low than 20% and the bare rockrate is higher than 61%; in medium rank, vegetation cover rate from 21% to40%, bare rock rate from 40% to 60%; in light rank, vegetation cover rate from40% to 60%, bare rock rate from 21% to 40%. Secondly it is for the first time that the paper surveys, studies, monitors andevaluates the structure and functions of artificial woods in karst rockydesertification areas. By the comparison of the structure and characteristics ofartificial vegetations, the paper thinks that the introduction of arboreal trees andherbaceous plants has formed a primary stereo structure with arboreal layer,bush layer and grass layer in the demonstration area and the structure isreasonable in total and bio-divers... |
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