Objective Niche and interspecific association are the basis and main method to study community structure. The purpose of this paper was to study the structural characteristics and dynamic changes in herb layer of burned Pinus tabuliformis forest in the southern Taihang Mountains at different restoration stages.
Method We focus on the niche characteristics and interspecific associations of the dominant species of herb layer plants in four burned areas of 13 years (S1), 7 years (S2), 6 years (S3) and 1 year (S4), then we calculated the niche width and niche overlap, and studied the interspecific association through the overall association test, χ2 test and Spearman rank correlation test. Then the ecological species groups were divided.
Result The dominance, niche width, and niche overlap of dominant species Carex lanceolata, Chrysanthemum chanetii and Artemisia stechmanniana were larger in different restoration periods. The overall association test showed that S1 was a significantly positive association, S2 and S4 were a significantly negative association, and S3 was an insignificantly positive association. χ2 test showed that the positive and negative association ratios of S1, S2, S3 and S4 were 2.33, 0.69, 0.84 and 0.63. Spearman rank correlation test showed that the number of positive association pairs in S1was greater than that of negative association pairs, while the number of positive association pairs in S2, S3 and S4 was less than the number of negative association pairs. The dominant species in S1, S2 and S3 can be divided into three ecological species groups represented by Carex lanceolata + Chrysanthemum chanetii, Artemisia stechmanniana and other dominant species. And 10 dominant species in S4 can be divided into three ecological species groups represented by Carex lanceolata, Chrysanthemum chanetii and Artemisia stechmanniana.
Conclusion Herb plant community in the burned area of southern Taihang Mountain has the greatest stability after 13 years of recovery. The niche and interspecific association may illuminate the interaction mechanisms such as species coexistence, distribution, structure changes in burned area, which could provide theoretical support in burned area management and plant distribution.