| In south slope of Xiaoxing'an Mountains,applying transect survey and sampling investigation,analyzing the collected data with SPSS13.0 statistic software as criteria of scale, and adopting indices(W_i) and Vanderploeg & scavia indices(E_i),the systemic survey on seasonal habitat selection by wild boars was conducted from April 2007 to April 2008; Moreover,in the farm belt lying to the south of forest,using GPS technique and sampling investigation,combining SPSS statistic software,the cut-and-try research on pattern of crop raiding by wild boars was developed.Based on the techniques of wildlife field investigation and analyses of SPSS 13.0 statistic software,the principal result was obtained as follows:Seasonal migration have been found in the wild boars in south,slope of Xiaoxing'an Mountains.In the horizontal position,the wild boars migrated to the north from the south of the forest in spring and summer,even furthest to the Wulahun Forest,which is on the north of the Longkou forest.When in fall back again,the wild boars sought for food in the south of the forest in winter.In the vertical direction,wild boars chose low altitude and slope as habitats in spring,and migrated to the higher altitude and showed selectivity to the middle slope in summer,untill fall wild boars avoided the high altitude and went back to the low slope,but in winter they avoided low altitude and slope,and randomly selected slope location.Food distribution was the most important factor.The habitat selections by wild boar changed with the differences of food distribution in different seasons,which was reflected on the changes in the principal components of factor analysis in different seasons.In spring,terrain factor was the chief factor in habitat selection by wild boars,including slope location,altitude,distance to water source and slope angle,in addition,sheltering factor, vegetation factor and the slope direction factor also worked.The broadleaf forest and conifeorus broadleaved forests were prefererd,and coniferous forest,farmland and meadow were avoided by wild boars.Subjecting to the food distribution in the terrain,canyons and pools in low altitude and slope location,which were abundant in herbage and invertebrates, were often preferd,and humid areas with fallen logs were also selected as food habitats,and the shady slope in shortage of food was avoided to select.The habitats with high canopy, moderate tree and shrub density and moderate distance to disturbance were also selected,but there was no selectivity in sheltering class.In summer,The broadleaf forest and conifeorus broadleaved forests were perfererd to coniferous forest,farmland and meadow wild boars.Subjecting to the food distribution, canyons and pools in low altitude and slope location were continued to select,and the higher altitude and middle slope location,which were affluent in berries,were more prefered.In and that of the rice was least(3.68±1.556%).Each factor of crop types,distance to water source and bed sites had the significantly influence on the damage area of a single foray.The damage area of maize was biggest(99.49±6.924 m~2),which of the rice was followed(77.90±41.159m~2),and the soybean was smallest(44.95±5.679 m~2);With the increasing distance to the water source(＜100m,100-200m,＞200m),the damage area of a single foray was declining,which was 115.97±11.130 m~2, 73.09±7.266 m~2 and 31.57±2.008 m~2,respectively;With the increasing distance to the bed site(＜1000m,1000-2000m,＞2000m),the damage area of a single foray was also,declining, which was 1108.17±10.204 m~2,80.73±7.724 m~2 and 66.16±18.763 m~2,respectively.In the analysis level of farmland,taking the frequencies as dependent variables and 4 environmental factors(mean distances of the foray events to the nearest bed sites,water sources and disturbance sources and crop types) as independent variable,the predicting model was established and the frequencies of crop raiding event caused by wild boars could be predicted with model. |
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