Chin J Plant Ecol ›› 2007, Vol. 31 ›› Issue (5): 814-824.DOI: 10.17521/cjpe.2007.0103

• Research Articles • Previous Articles     Next Articles

IMPACTS OF TOPOGRAPHY ON THE SPATIAL PATTERN OF THE AGE OF FOREST COMMUNITY

HU Zhi-Wei1, SHEN Ze-Hao1,*(), LÜ Nan1, ZHAO Jun1, LI Dao-Xing2, CHEN Hua3, WANG Gong-Fang2   

  1. 1Department of Ecology, College of Environmental Sciences, and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing 100871, China
    2Dalaoling National Forest Park, Yichang, Hubei 443000, China
    3Yichang Forest Inventory and Design Institute, Yichang, Hubei 443000, China
  • Received:2006-05-25 Accepted:2006-12-08 Online:2007-05-25 Published:2007-09-30
  • Contact: SHEN Ze-Hao

Abstract:

Aims Our objective is to assess the impacts of topography, a main source of spatial and temporal environmental heterogeneity, on the dynamics of mountain forest communities.

Methods We sampled a 200 m×100 m plot of mixed evergreen broad-leaved and deciduous forest at Mt. Dalaoling in the Three Gorges Region of China using a 10 m×10 m grid. We measured the topography and set up a digitalized elevation model with resolution of 1∶500. We then took tree ring samples of 16 common tree species, fitted species specific diameter-age models and estimated community age in each of the 200 grids. Multivariate linear regression and ANOVA were applied to analyze the relationship between community age and habitat variables.

Important findings Power model successfully describes the quantitative relationship between DBH and age in all species. Community ages of the grids range from 14 to 179 years old, with a mean of 95 years old. The oldest individuals in the grids include 24 tree species, but the top 5 species make up the oldest individuals in 68.5% of the grids. Significant correlations exist between estimated community age and stream impact index, position, slope, sum of basal area of disturbed trees, and growth rate index, implying that soil erosion critically impacts community development, although species-specific potential age is a constraint of community age. We suggest that topography impacts on community age by controlling the spatial pattern of disturbance regime (by surface erosion), and habitat choice of species with diversified ecological strategies. However, our quantitative estimate of community age has considerable uncertainty due to the complexity of the object studied and the method applied.

Key words: topography, mixed evergreen broad-leaved and deciduous forests, community age, spatial pattern, disturbance, Mt. Dalaoling