journal6 ›› 2011, Vol. 32 ›› Issue (1): 79-84.

• Biological resources • Previous Articles     Next Articles

Relationship Between Understory Vegetation and Canopy Stratum Trees in Huitong Forest Region

  

  1. (1.Huitong Experimental Station of Forest Ecology,Chinese Academy of Sciences,Shenyang 110016,China;2.Jishou University,Jishou 416000,Hunan China;3.Forestry Bureau of Baojing,Baojing 416500,China;4.Department of Botany,Panjab University,Chandigarh 160014,India)
  • Online:2011-01-25 Published:2012-04-10

Abstract: Non-metric multidimensional scaling (NMS) analysis was used to get two direct gradients in canopy tree species-site relationships from canopy data set,then principal components analysis was used to extract two principal components (PC1 and PC2) from canopy variables including the two direct gradients and other canopy parameters as the environment variables of understory vegetation,and how the two principal components affect understory vegetation was studied,not only in species diversity and composition but also with reference to species assemblages.No significant effect of forest structure (represented by PC1 scores) on diversity of understory vegetation was found,however canopy composition (represented by PC2 scores) has a strong influence,explaining 36.9% variation in understory species diversity.DCCA (detrended canonical correspondence analysis) ordination to was used to explore the changes in understory species composition-canopy relationships,and canopy variables was found to significantly influence the distribution of the understory species.For example,Elaeocarpus decipiens,Aleurites Montana,Elaeagnus pungens,Cyclobalanopsis glauca,Diospyros kaki. var. sylvestuis and Cinnamomum parthenoxylon are strongly associated with forest structure,and Hemiboea henryi,Anisocampium sheareri,Akebia trifollata,Dendrobenthamia honghongensis and Phoebe sheareri are strongly associated with canopy composition.However forest structure is much weaker than canopy species composition in explaining understory composition.Null-model was also used to test the understory species co-occurrence patterns along three different forest structure and canopy composition scales.Only canopy composition significantly influences Stone and Roberts's C-score.The results suggest that canopy composition is among the most influential forces in ecosystem process,and imply that canopy composition might have played a major role in creating observed understory community patterns.

Key words: canopy composition, forest structure, ordination, evergreen broad-leaved forest

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