不同浓度湿润剂对高寒草甸鼠害型秃斑地改良效果研究

Study on improvement effect of different concentrations of wetting agentson alpine meadowrodent-damaged bald land

摘要:

【目的】 秃斑地土壤斥水性是限制其植被恢复的重要因素。降低秃斑地土壤斥水性，增加土壤持水性是植被恢复的优选措施之一。【方法】 选取青藏高原东部碌曲县典型秃斑地，喷施100、200、300 和450 mL/m3 浓度的湿润剂，以未喷施湿润剂的秃斑地为对照（CK），对比分析喷施区和对照区土壤物理性状和植物群落特征，并采用相关性分析探讨土壤因子对植物群落特征的影响，灰色关联度分析法，评价改良效果。【结果】 1） 不同浓度湿润剂喷施后，土壤最大持水量（MC）、毛管孔隙度（CP）和总孔隙度（TP）均大于CK（P＜0. 05），各浓度处理间无显著差异；2） 湿润剂浓度为200 mL/m3的喷施区，多年生杂类草丰富度显著大于其他浓度处理，大于CK（P＜0. 05）；3）土壤最大持水量（MC）和毛管持水量（CC）与植物高度（ht）显著相关（P＜0. 05）。【结论】 秃斑地喷施湿润剂可提高土壤持水能力，增加植物物种丰富度，湿润剂浓度为200 mL/m3喷施效果最佳。

Abstract:

【Objective】 Soil water repellency is an important factor limiting vegetation restoration in bare land.Reducing soil water repellency and increasing soil water holding capacity are key measures foreffective vegetation restoration【Method】 A typical bald spot in Luqu County，eastern Qinghai-Tibet Plateau，was selected for the study.Wetting agents with concentrations of 100 mL/m³，200 mL/m³，300 mL/m³ and 450 mL/m³ were applied. An untreatedbald spot served as the control （CK）. The study compared and analyzed the soil physical properties and plantcommunity characteristics between the treated and control areas. Correlation analysis was used to explore the effectsof soil factors on plant community characteristics，and the grey correlation analysis method evaluated the improvementeffect.【Result】 （1） After spraying different concentrations of wetting agents，the soil maximum water holdingcapacity（MC），capillary porosity（CP） and total porosity（TP） were significantly higher than those in the control（ P＜0. 05），with no significant differences among the different concentrations（P＞0. 05）.（2） In the area treatedwith200 mL/m3 concentration ofwetting agent ，the richness of perennial forbs was significantly higher compared to otherconcentration treatments and CK（P＜0. 05）.（3） The soil maximum water holding capacity（MC） and capillary waterholding capacity（CC） were significantly correlated with plant height（ht）（P＜0. 05）.【Conclusion】 Spraying wettingagent on bald spot can improve soil water holding capacity and increase plant species richness. A concentration of200 ml/m³ is identified as the most effective for these improvements.