| Daxing'anling is one of the most important forest areas in China, but it is also an area prone to suffering forest fire. In May 6, 1987, a catastrophic forest fire took place, which affected more than 1.33×l06 ha of natural forest and produced a strikingly heterogeneous mosaic of burn severities and islands of unburned vegetation across the landscape. After about ten years, due to natural succession and anthropogenic disturbance, the spatial pattern of the landscape in this area has changed greatly. In this dissertation a typical area was selected as a case study, which is the Tuqiang forest bureau, including two forestry farms, namely, Yuying and Fendou, covering more than 1.2× 10s ha, it is also one of the most severely burned bureaus during this fire.Based on the widely investigation of the background information in the study area, and supported by the Geographic Information System (GIS) and Remote Sensing(RS) , the two digital forest stand maps(1987 and 2000) and DTM data were overlaid and the spatial and attribute database were produced. According to this, basic characteristics and changing of landscape structure and spatial pattern were widely and thoroughly analysed. The relations of the topography and the change of the spatial pattern were also analysed by using Distribution Index and the Partial- Correlation Analysis. At last the study results show that:◆ The spatial pattern changed greatly, the reserved rate was only 22%. The change of landscape has not reached a stable equilibrium, but the trend is stable. To day, the burned blank was almost restored. The proportion of forest area increased 47.6% in 1987 to 81.3% in 2000, among the forest landscape patch types, coniferous is the dominant, about 47.6%, which is the result of the intensive planting after fire.◆ Topography is one of the most important factors for the characteristics and the change of the spatial pattern of the forest landscape. Topography decides the spatial distribution of the environmental sources and also affects natural succession and humans activity. In this dissertation three topographic factors were included, that is elevation, slope and aspect, among which the effect of slope was the strongest, elevation was the second and aspect was the last. ◆ Besides topography, burn severity and anthropogenic disturbance were also important to the spatial pattern and the change of the forest landscape. For example, on the burned blank, 49.4% of the area was converted to coniferous forest in a comparatively short time, which was resulted from the intensive human reforestation. The regressive succession from partial coniferous forest to needle -broad-leaved mixed forest was an obvious evident to show that the burn severity also has a strong effect on the variability in post fire landscape. ◆ Artificial reforestation and burn severity were controlled by the topography. The essential rule of artificial restoration is Matching tree by improving soil or Matching site by improving treespecies, and the livability of the regenerated coniferous forest reflected the affection of the topography on the artificial reforestation. According to the analytic results in this dissertation, we can find that slope was the pivotal factor for the conversion of the burned blank into coniferous forest, and the Partial Correlation Coefficients is -0.6835. Bum severity is also affected by the topography. The basic rule is that with the increasing of slope and elevation, the burn will become much severer. But to the aspect, it was contrarious (excluding the nonaspect).◆ Nondimensional distribution index was able to describe the spatial pattern of each landscape patch type and indicate the affection of the topography on the change of the pattern. For excluding the disturbance of the area, distribution index can describe the difference between the actual distribution and the standard distribution of each patch type on the topographic gradient. And according to this, kinds of comparative analyses were availed.
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