切根和施掺混肥对草甸草原植物群落特征及物种多样性的影响

Effects of root cutting and mixed fertilizer application on plant community characteristics and species diversity in meadow steppe

摘要:

【目的】切根、施肥对改良草地、维持草原生态系统养分平衡有积极意义。探讨切根、切根+不同浓度掺混肥对草地植物群落的影响,为退化割草地的恢复和改良提供理论依据。【方法】采用切根、切根+不同浓度掺混肥处理,分析其对内蒙古呼伦贝尔退化草地植物群落物种组成及重要值、数量特征和物种多样性的影响。【结果】切根和施掺混肥共同调控可显著提高整体群落重要值、群落高度、密度及地上生物量,在切根+300 kg/hm2掺混肥处理下值最高,而植物群落α-多样性最低。禾本科植物重要值与其他科重要值之间存在显著负相关(P<0.05,R=-0.65*);Simpson优势度指数与Margalef丰富度指数(P<0.01,R=0.76**)、Shannon-Wiener多样性指数与Pielou均匀度指数(P<0.01,R=0.90**)均呈极显著正相关。【结论】退化草甸草原在改良过程中,切根和施掺混肥共同作用能够有效提高群落的重要值及生产力,其中切根+300 kg/hm2掺混肥处理下修复效果最好。

Abstract:

【Objective】Root cutting and fertilization measures have positive implications for grassland improvement and maintaining the nutrient balance of grassland ecosystems. This paper investigates the effects of root cutting and root cutting + different concentrations of mixed fertilizer on grassland plant communities through field trials,providing reference and theoretical basis for the restoration and improvement of degraded mowing grasslands.【Method】Root cutting and root cutting + different concentrations of mixed fertilizer were used to study their impacts on species composition, importance values, quantitative characteristics, and species diversity of plant communities in degraded mowing grasslands in Hulunbuir, Inner Mongolia.【Result】The co-regulation of root cutting and mixed fertilizer application significantly increased the overall importance value,community height,density,and above-ground biomass,with the highest values observed under the root cutting + 300 kg/hm2 mixed fertilizer treatment. In contrast, the trend in the α-diversity of the plant community was opposite. There was a significant negative correlation between the importance value of graminoids and that of other families (P<0.05,R=-0.65*). The Simpson dominance index was highly significantly and positively correlated with the Margalef richness index (P<0.01,R=0.76**),and the Shannon-Wiener diversity index was highly significantly and positively correlated with the Pielou evenness index (P<0.01,R=0.90**).【Conclusion】During the improvement process of degraded mowing grasslands in meadow steppes, the combined action of root cutting and mixed fertilizer application can effectively enhance the importance value and productivity of the community, with the best restoration effect observed under the root cutting + 300 kg/ha mixed fertilizer treatment.