Chin J Plan Ecolo ›› 2013, Vol. 37 ›› Issue (1): 26-36.DOI: 10.3724/SP.J.1258.2013.00003

• Research Articles • Previous Articles     Next Articles

Environmental factors correlated with species diversity in different tropical rain forest types in Jianfengling, Hainan Island, China

XU Han1,2, LI Yi-De2*, LUO Tu-Shou2, CHEN De-Xiang2, and LIN Ming-Xian2   

  1. 1State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing 100191, China;

    2Research Institute of Tropical Forestry, Chinese Academy of Forestry, Guangzhou 510520, China
  • Received:2012-05-14 Revised:2012-12-25 Online:2013-01-01 Published:2013-01-15
  • Contact: LI Yi-De

Abstract:

Aims Environmental factors are key factors impacting species distribution and determining species richness. An important question is whether the major environmental factor are the same in old-growth forests and secondary forests produced by logging. This question is very important for monitoring long-term changes in secondary tropical rain forests.
Methods A unique, robust data set consisting of 164 625 m2 quadrats in a 160 km2 tropical rainforest was set up from August 2007 to June 2009 in the middle of the Jianfengling Natural Reserve, Hainan Island, China. Forest logging history was determined and 17 environmental factors were measured for each quadrat. First, we analyzed the relationship among these 17 factors. Then, these quadrats were classified into three forest types with different logging history: old-growth forests, diameter-limit logged forests and clear-cut forests. Canonical correspondence analysis (CCA) was used to analyze the environmental factors impacting species distributions. Step-forward multiple regression was used with and without considering spatial autocorrelation in the data set to disclose which environmental factors determined species richness.
Important findings The environmental factors impacting species distribution and determining species richness changed because of differences of forests logging history. Elevation is the second most important factor influencing patterns of species diversity. CCA showed that species distribution in old-growth forests is closely related to elevation, soil exchangeable calcium content, soil exchangeable magnesium content and four soil physical factors (soil density, maximum water holding content, capillary water-holding content and capillary porosity). Importance of soil total phosphorous content and available phosphorous content was greater in logged forests, but the importance of soil exchangeable calcium content and exchangeable magnesium content was lower in clear-cut forests. Multiple regression analysis also showed that species richness was significantly correlated with elevation and soil exchangeable calcium in the old-growth forests. While species richness was correlated with elevation, soil total phosphorous content and soil available potassium content in the diameter-limit logged forests and was only correlated with elevation in the clear-cut forests. Furthermore, it is suggested it is better to compare the spatial autocorrelation models with other models to describe the relationship between environmental factors and species richness, even it does not always exist in the ecological data set with spatial characteristics.