桂西南岩溶区不同恢复模式群落生物量及林下植物多样性

目的]研究桂西南岩溶区不同恢复模式群落的生物量及其林下植物多样性的特点,为该区域的生物多样性保护、生态功能恢复效果评价积累基础数据。方法]以桂西南岩溶区4种不同恢复模式为研究对象,采用样方法对林下植物多样性进行研究;采用收获法研究灌木层与草本层的地上、地下生物量及凋落物层现存量;采用异速生长模型来估算乔木层的地上生物量,并参考IPCC根茎比来量化乔木的地下生物量。结果]表明:共调查记录林下植物85种,隶属于46科,81属,其中,灌木植物25科,46属,50种;草本植物21科,35属,35种;不同恢复模式群落生物量的变化趋势为自然恢复林(166.66 t·hm-2)任豆林(48.61 t·hm-2)吊丝竹林(36.54 t·hm-2)灌草坡(0.96 t·hm-2)。结论]不同恢复模式灌木层物种丰富度差异不显著,最高的为灌草坡(16种),其次为任豆林(15种),最低为自然恢复林(12种);草本层物种丰富度最高的为任豆林(12种),其次为灌草坡(10种),最低为自然恢复林(4种)。自然恢复林乔木不同组分生物量与任豆林、吊丝竹林之间差异显著(P0.05);灌草坡的灌木、草本地上生物量与吊丝竹林、任豆林、自然恢复林之间差异显著(P0.05)。吊丝竹林、任豆林的灌草生物量表现为草本层灌木层,而灌草坡与自然恢复林的灌草生物量则表现为灌木层草本层。

Community Biomass and Understory Plant Diversity under Different Vegetation Restoration Models of Karst Region in Southwest Guangxi

Objective]To investigate the community biomass and understory plant species diversity in four different restoration models in karst region of Southwest Guangxi in order to accumulate information for biodiversity conservation and the restoration of ecological function in the region. Method]Four different restoration models were selected as the research object, and the understory plant species diversity were studied by samples, the ground and underground biomass of shrub layer and herb layer was studied by the harvest method; the arbor layer biomass were studied by using allometic models and the ratio of root and stem recommended by IPCC. Result]85 species belonging to 81 genera of 47 families were recorded, among of which, 50 species belonging to 46 genera of 25 families were shrubs and 35 species belonging to 35 genera of 22 families were herbs. The biomass of different vegetation restoration models showed that the highest was the natural restoration forests (166.66 t·hm^-2) followed by Zenia insignis forest (48.61 t·hm^-2), Dendrocalamus minor forest (36.54 t·hm^-2), and the lowest was the shrub grassland (0.96 t·hm^-2).Conclusion]The richness of shrub species showed no significant difference among different models, the highest richness was the shrub grassland (16 species), and then the Zenia insignis forest (15 species), the lowest was the natural restoration forests (12 species). The highest in herb was the Zenia insignis forest (12 species), then the shrub grassland (10 species), and the lowest was the natural restoration forests (4 species). In the tree layer, the biomass of different components of the natural restoration forest was significant different with Zenia insignis and Dendrocalamus minor forests (P<0.05). The aboveground biomass in the shrub-grassland was significant different with that of the others (P<0.05). The litter biomass was not significant (P<0.05). The biomass of herb layer was higher than that of the shrub layer in the Zenia insignis and Dendrocalamus minor forests; but in natural restoration forest and shrub-grassland, it showed the opposite. The precaution management for four different restoration models in the karst area of Southwest Guangxi is put forward based on this result.