Chin J Plan Ecolo ›› 2008, Vol. 32 ›› Issue (3): 582-590.DOI: 10.3773/j.issn.1005-264x.2008.03.007

• Research Articles • Previous Articles     Next Articles


ZHANG Liang1; XING Fu1,2*; YU Li-Li1; XU Kun1; SUN Zhong-Lin1; Lü Xian-Guo2   

  1. 1Key Laboratory of Vegetation Ecology, Ministry of Education, Changchun 130024, China; 2 Northeast Institute of Geography and Agricultural Ecology, Chinese Academy of Sciences, Changchun 130012, China
  • Online:2008-05-30 Published:2008-05-30
  • Contact: XING Fu

Abstract: Aims Island forest is a major vegetation type of the Sanjiang Plain in northeastern China. However, its species diversity is at risk of decline. Our objectives were to 1) describe the flora, 2) determine the level of plant diversity, and 3) determine relationships between diversity indices and patch characteristics (area, perimeter and shape index). 
Methods We used Quick Bird satellite image data to identify a 65 km2 study site . The quadrat method was used to investigate community patch characteristics such as area, perimeter and shape index, which were analyzed with Erdas Imagine 8.7. Four indices were selected to describe plant diversity: richness (R), Simpson (D), Shannon-Wiener (H′), and Pielou (Jsw).
Important findings The 19 patches of the island forest had 140 species of vascular plants of 44 families and 102 genera dominated by cosmopolitan and temperate genera. Our data suggested that, compared with the neighboring community in the Honghe Nature Reserve, some plant species had disappeared. The diversity indices were significantly different among shrub layers of the Populus davidiana, Betula platyphylla and P. davidiana + B. platyphylla communities (p<0.05). Additionally, R, D and H′indices of different layers were as follows: herb layer > shrub layer > tree layer, with significant differences among them (p<0.01). While statistically significant correlations were observed between the R index and patch area (r=0.591, p<0.01), perimeter (r=0.674, p<0.01) and shape index (r=0.584, p<0.01), no correlations were noted for the D, H′ and Jsw indices. Diversity levels remained relatively high after human disturbance. The greatest difference among patches was noted in herb layers. Our data also suggested that gap disturbance was an important cause of higher understory diversity. Plant species richness increased with patch area, perimeter and shape index, most likely resulting from edge effects. Our results demonstrated that the island forest plays an important role in preserving plant diversity in the region.