The Impact Of Edge Effect On Population Number And Distribution Of Red Deer In The Wanda Mountain

Habitat edges have important effects on wildlife behavior and habitat selection, and different effects be produced by different habitat types. In the winters of 2003, 2004 and the spring of 2005, 11 habitat factors affecting population number and distribution of red deer, farmland-forest edge effect, frost-shrub edge effect were respectively studied with the line transect method in the Wanda Mt Forest Area, Heilongjiang province. The main findings are as follows:First , we conducted the investigation of forest-shrub edge effects. The width of forest-shrub edge is 110 meters. At the same time, we also studied the potential factors affecting population number and distribution of red deer in the habitats in different distances to the edge. The result show that, Forest-shrub edge had a positive effect on activity and distribution, which meant the activity and distribution density of red deer was higher than those in bordered on interior of shrub or forest, red deer selected habitat in the deep forests far from the forest-shrub edge and the behavior of habitat selection is not random. Red deer have higher activity traces' densities in the forest-shrub edge than in the forest and shrub. Red deer's preference index have difference to shrub, forest-shrub edge and forest and red deer's preference index is highest in forest-shrub edge (H_I=0.332), then shrub (H_I=0.021), lowest forest (H_I=0.004) . By studying the relationship between the vegetation factors with different distances to forest-shrub edges and red deer's activity traces'densities, we found that although arbor density and cover degree differed in the habitats with different distances to forest-shrub edges, red deer distribution and move mainly in the forest-shrub edges.And we also studied the farmland-forest edge effects. The width of farmland-forest edge attained was 50 meters. We also studied the potential factors affecting population number and distribution of red deer in the habitats in different distances to the edge. The result show that farmland-forest edge had a negative effect, namely the activity of red deer mainly were in a distance range of 200-680 m from forest interior to the edge, and little in the edge or farmland, arbor density differs significantly in the habitats with different distances to the edge, but coverage, crown closure and cover degree did not significantly differ. Habitat factors have little correlation with red deer's activity traces'densities. But the occurrence of such edges made red deer's use of different habitats not random. Red deer's preference index have difference to forest, farmland-forest edge and farmland, and red deer's preference index is highest in forest(H_I=0.043) , then farmland-forest edge (H_I=0.032) , lowest farmland (H_I=0.000) .By the comparison of effects between forest-shrub and farmland-forest edge, the habitat factors of forest-shrub edge that had a positive edge effect on activity, population number and distribution of red deer were shrub coverage and arbor crown density to the edge, not arbor density and cover degree. While the habitat factors of farmland-forest edge that had a negative edge effect were nearby human disturbance activity and foraging sites of red deer were mainlylocated the distance of 600- 800 m from forest interior to farmland. In the Wanda Mountains, red deer mainly distributed in the landscape mixed with forest and shrub, with low fragmentation. In the landscapes mixed with farmland and forest with high fragmentation, edges have negative effects on red deer's activities and there are rare distributions of red deer in such landscapes.