甘肃景泰北部干旱荒漠区封育沙地植物生态位研究

利用Levins生态位宽度公式和Pianka生态位重叠公式,对甘肃省景泰县北部沙生植被主要植物种在不同恢复方式下的生态位宽度和生态位重叠进行计测分析。结果表明:在自然恢复沙地灌木层中,沙蒿的生态位宽度最大,BL值为0.966,其次是驴驴蒿,BL值为0.935。人工+自然恢复沙地灌木层中,仍是沙蒿的生态位宽度最大,BL值为0.962,其次是花棒和沙拐枣,BL值分别为0.900和0.897;在自然恢复沙地草被层中,禾草的生态位宽度最大,其次是五星蒿,BL值分别是0.989、0.959。人工+自然恢复沙地草本中,五星蒿的生态位宽度最大,其次是刺蓬,BL值分别是0.952、0.942;自然恢复沙地灌木种群间生态位重叠最大的是荒漠锦鸡儿与白沙蒿,NO值为1。人工+自然恢复沙地灌木种群间生态位重叠最大的是柠条与沙拐枣,NO值为0.980;具有较宽生态位的五星蒿、刺蓬、禾草、沙米等草本间均有较大的生态位重叠,生态位宽度和生态位重叠之间不是直接的线形关系。

Plant niche of enclosed sandy land in arid desert area in northern Jingtai County of Gansu

The study on the niche characteristics of main plant species in different vegetation types in desert area of northern Jingtai County,Gansu Province was conducted by using Levins index of niche breadth and Pi-anka index of niche overlap.The results showed that,In:,Artemisia arenaria had the widest niche breadth(B L value 0.966)which was followed by Artemisia dalai-lamae (B L value 0.935)on natural restoration sandy land in shrub layer.And Artemisia arenaria had the widest niche breadth(B L value 0.962)which was followed by Hedysarum scoparium and Calligonum mongolicum (B L value 0.900 and 0.897)on natural + artificial restora-tion sandy land.Grass had the widest niche breadth(B L value 0.989)which was followed by Bassia dasyphylla (B L value 0.959)on natural restoration sandy land in grass layer,And on natural+ artificial restoration sandy land,Bassia dasyphylla had the widest niche breadth(B L value 0.952)which was followed by Salsola ruthenica (B L value 0.942).Largest overlap value was between Caragana spp and Artemisia sphaerocephala on natural restoration sandy land in shrub layer(NO value 1).And on natural+ artificial restoration sandy land,the largest overlap value was between Caragana korshinskii and Calligonum mongolicum ,(NO value 0.980 ).All those species with wider niche breadth(Bassia dasyphylla ,grass,Salsola ruthenica and Agropyron cristatum )had larger niche overlap.The niche breadth and niche overlap did not show a linear relationship.