浑善达克沙地中部斑块格局影响植物多样性及功能性状

景观格局与植物多样性之间的关系已被广泛研究,然而,斑块格局如何影响植物多样性,以及这些影响的边缘类型差异尚不清楚。为从植物功能性状角度揭示斑块格局影响植物多样性的机制,该研究采用不同边缘类型的斑块,利用两年调查的705个样方数据,结合遥感卫星图像解译和空间信息分析,根据植物群落的空间位置和斑块格局,按照向内、向外、向内成核和向外成核4种边缘类型将浑善达克沙地中部的斑块进行分类,采用Duncan新复极差法比较了4种边缘类型斑块格局与植物功能性状多样性关系的差异,应用Pearson相关系数和冗余分析(RDA)法量化了斑块格局对植物多样性的影响。结果发现,植物丰富度和多样性指数与斑块格局密切相关,这些关系存在着边缘类型的显著差异,表现出不同的功能性状。对于向内边缘,边缘指数与丰富度负相关,和C₄植物比例正相关;对于向外边缘,边缘指数与C₄植物比例正相关;对于向内成核边缘,边缘密度与多年生植物和虫媒植物比例正相关;对于向外成核边缘,边缘角度和指数与物种Shannon-Wiener指数和Simpson指数正相关,与Pielou指数、丰富度和动物传播植物...

Effects of patch pattern on plant diversity and functional traits in center Hunshandak Sandland

Aims We address the issue of adapting patch pattern for improved plant biodiversity conservation in sandy grasslands by assessing the role of edge type in the influences of patch pattern on plant diversity and functional traits. We test the hypotheses that plant richness, alpha and beta diversity would vary according to patch pattern but that these effects would vary according to edge type, through adaptation of plant functional traits. Methods Jointing satellite imagery interpretation, 705 plots from two-year surveys and spatial analysis, patch edges in center Hunshandak Sandland were categorized into four types. Duncan’s differences were tested across four edge types. Pearson’s correlation and redundancy analysis (RDA) were used to discern the patch contributions. Important findings Plant richness and diversity indices are closely related with patch patterns, these relations vary significantly across edge types, demonstrating different functional traits. For inward edge, edge metrics attributes to richness reduction and C₄ plant proportion, mean perimeter-area ratio (MPAR) positively related to nitrogen-fixed species proportion. For outward edge, mean patch fractal dimension (MPFD) negatively related to richness, MPAR positively related to the proportion of nitrogen-fixing species, edge metrics positively related to C₄ proportion. For inward nucleating edge, MPAR, total edge (TE) and landscape area (TLA) positively related to perennial plants, TE and TLA positively linked to insect-pollination plants. For outward nucleating edge, angle and pattern metrics positively related to Shannon-Wiener and Simpson index, negatively related to Pielou index, richness and animal-seed dispersing plants. Patch pattern distressing plant diversity through edge effects can be moderately interpreted by plant practical qualities and edge metrics. It must be well thought-out in landscape management, vegetation restoration and biodiversity conservation.