| 摘要: |
| 【目的】研究石漠化区域植被群落及土壤物理特征，为石漠化脆弱生态环境综合治理及植被恢复重建提供重要依据。【方法】在黔西南石漠化典型区域，选取重度、中度、轻度和无石漠化4个等级的样地，测定样地中植被盖度与生物量，计算植物群落的生物多样性指数（多样性指数、丰富度指数、均匀度指数、优势度指数）；采集0~10，10~20，20~30 cm土层的土样，测定土壤体积质量、含水量、田间持水量、毛管持水量、总孔隙度、毛管孔隙度；最后分析了6个土壤物理指标与植被盖度、生物量和生物多样性指数的相关性。【结果】1）随着石漠化程度的改善，草本生物量下降，灌木及乔木生物量均显著上升，植被总生物量和盖度均显著上升。2）随石漠化程度的改善，物种多样性指数、丰富度指数和均匀度指数均总体上升，其中无石漠化样地以上3个指标分别为2.26，10.50和1.01，显著高于其他等级石漠化样地（P<0.05）；而重度石漠化样地优势度指数达0.39，显著高于其他等级石漠化样地（P<0.05）。3）随着石漠化程度的改善，土壤含水量、毛管持水量、田间持水量、土壤总孔隙度和毛管孔隙度平均值均增加，而土壤体积质量则下降。4）相关性分析结果表明，植被生物量、盖度分别与土壤体积质量呈显著和极显著负相关关系，与土壤含水量、毛管持水量、田间持水量、总孔隙度和毛管孔隙度均呈显著或极显著正相关关系。多样性指数、均匀度指数与土壤体积质量呈显著的负相关关系（P<0.05），与田间持水量和总孔隙度呈显著的正相关关系（P<0.05），与土壤含水量呈极显著的正相关关系（P<0.01）；优势度指数仅与毛管孔隙度呈显著的正相关关系（P<0.05）；而丰富度指数与各土壤物理指标间均无显著相关关系。【结论】贵州省黔西南州石漠化演变过程中，植被、土壤物理特征均产生了显著改变，地表植被的演进对土壤物理特性产生了较为明显的促进作用。 |
| 关键词: 石漠化 植被群落 土壤物理特征 演变过程 黔西南 |
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| 基金项目:生态环境部生态保护红线专项；国家自然科学基金项目（21360122）;国家重点研发计划项目（2016YFC0500205） |
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| Characteristics of vegetation and soil physical properties in evolution processes of rocky desertification in Southwest Guizhou |
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WEN Linqin,LI Zhongfei,LI Mingyu,et al
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| Abstract: |
| 【Objective】The characteristics of vegetation and soil physical properties in rocky desertification areas were studied to provide basis for comprehensive management of fragile ecological environment and vegetation restoration and reconstruction.【Method】Four grades of severe,medium,slight and no rock desertification were selected in the typical rocky desertification area in southwest Guizhou.The vegetation coverage,biomass,biodiversity indexes (Shannon-Wiener index,richness index,evenness index and dominance index),and soil physical properties (soil water content,soil bulk density,field water capacity,capillary water holding capacity,total porosity,and capillary porosity in layers of 0-10,10-20 and 20-30 cm) were measured respectively.Also,the correlations between soil physical properties and vegetation characteristics were analyzed.【Result】1) With the improvement of rocky desertification,biomass of surface herbage vegetation decreased,while biomass of shrubs and trees increased significantly and total biomass and vegetation coverage increased significantly.2) Shannon-Wiener index, richness index and evenness index all increased,and reached to 2.26,10.50 and 1.01 in no rocky desertification sample plots and were significantly higher than those at other grades (P<0.05).While the dominance index was highest on severe rocky desertification sample plots (P<0.05),which reached to 0.39.3) The soil water content,capillary water capacity,field water capacity,total soil porosity and capillary porosity increased with the improvement of rocky desertification,while soil density decreased.4) The results of correlation analysis showed that vegetation biomass and coverage had significant negative correlation with soil bulk density,and significant positive correlation with soil water content,capillary water capacity,field water capacity,total porosity and capillary porosity.Shannon-Wiener index and evenness index had significant negative correlation with soil bulk density (P<0.05),significant positive correlation with field capacity and total porosity (P<0.05),and extremely significant positive correlation with soil water content (P<0.01).Dominance index had significant positively correlation with capillary porosity (P<0.05).However,there was no significant correlation between richness index and soil physical properties.【Conclusion】The characteristics of vegetation and soil physical properties improved significantly in the process of rocky desertification evolution in Southwest Guizhou.The evolution of above-ground vegetation played significant role in promoting soil characteristics. |
| Key words: rocky desertification vegetation community soil physical characteristics evolution process Southwest Guizhou |
