| 秦岭中段不同恢复阶段弃耕农田植物多样性变化及其驱动因素 |
| 摘要点击 1080 全文点击 158 投稿时间：2023-03-01 修订日期：2023-04-25 |
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| 中文关键词 植被恢复 植物多样性 生态化学计量学 土壤胞外酶 土壤养分 枯落物养分 |
| 英文关键词 vegetation restoration plant diversity ecological stoichiometry soil extracellular enzymes soil nutrient litter nutrient |
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| 中文摘要 |
| 植被恢复过程往往伴随着显著的地上植物多样性的变化，探讨枯落物养分-土壤养分-酶活性化学计量对地上植被变化的驱动机制，对于维持区域生物多样性保护和生态稳定至关重要.以秦岭不同恢复年限（1、8、16、31和50 a）的典型弃耕农田为研究对象，通过野外调查分析了植被恢复过程中植物群落多样性的变化特征，测定了枯落物养分、土壤养分、β-1，4-葡萄糖苷酶（BG）、纤维二糖水解酶（CBH）、β-1，4-N-乙酰基氨基葡萄糖苷酶（NAG）、亮氨酸氨基肽酶（LAP）和酸性磷酸酶（AP）这5种胞外酶活性等指标，探讨了植被恢复过程中枯落物养分、土壤养分和酶活性化学计量比的变化特征及其对植物多样性变化的驱动机制.结果表明：植物群落多样性指数随植被恢复年限增加均呈先减小后增大的趋势，在恢复16 a时最小；主成分分析结果表明，植被恢复不同年限植物群落多样性指数及枯落物-土壤-酶化学计量特征之间有显著区别，植物群落多样性指数与枯落物碳磷比及枯落物氮磷比具有强烈的正相关关系，而与土壤酶碳磷比（EEA C∶P）具有明显的负相关关系；冗余分析结果表明EEA C∶P对植被恢复过程中植物多样性变化的解释率最高，为25.93%，其次为土壤全磷（TP），解释率为5.94%，是调控植物多样性变化的关键因子.综上所述，秦岭中段弃耕农田植被恢复后期植物种类和数量明显增多，土壤环境的变化影响了微生物的代谢活动从而改变了酶活性，枯落物-土壤-土壤胞外酶通过反馈与调节对群落环境和植物多样性产生影响，EEA C∶P和TP是植被恢复过程中地上植物多样性变化的主要驱动因素. |
| 英文摘要 |
| The process of vegetation restoration is often accompanied by significant changes in aboveground plant diversity. To explore the driving mechanism of litter nutrient-soil nutrient-enzyme activity stoichiometry on aboveground vegetation change is of great importance for maintaining regional biodiversity conservation and ecological stability. Taking typical abandoned farmland of different restoration years （1， 8， 16， 31， and 50 a） in the Qinling Mountains as the research object， the variation characteristics of plant community diversity during vegetation restoration were analyzed through field investigation. Litter nutrients， soil nutrients， and the activities of five extracellular enzymes， including β-1，4-glucosidase （BG）， cellobiohydrolase （CBH）， β-1，4-N-acetylglucosaminidase （NAG）， leucine aminopeptidase （LAP）， and acid phosphatase （AP）， were determined. The characteristics of litter nutrients， soil nutrients， and enzyme stoichiometric ratios during vegetation restoration and the driving mechanism of plant diversity changes were discussed. The results showed that the plant community diversity index firstly decreased and then increased with the increase in vegetation restoration years， and the minimum was reached at 16 years after restoration. The results of principal component analysis showed that there were significant differences between total plant community diversity index and litter-soil-enzyme stoichiometric characteristics in different years of vegetation restoration. The plant community diversity index had a strong positive correlation with litter C∶P ratio and litter N∶P ratio but had a negative correlation with soil enzyme C∶P ratio （EEA C∶P）. The results of redundancy analysis showed that soil EEA C∶P had the highest explanation rate of plant diversity changes during vegetation restoration （25.93%）， followed by soil TP （5.94%）， which was the key factor regulating plant diversity changes. In conclusion， plant species and quantity increased significantly in abandoned farmland in the middle part of the Qinling Mountains at the late stage of vegetation restoration. Changes in the soil environment affected microbial metabolic activities and thus changed enzyme activities. Litter-soil-soil extracellular enzymes affected the community environment and plant diversity through feedback and regulation. EEA C∶P and TP were the main driving factors of aboveground plant diversity change during vegetation restoration. |
