不同恢复措施下植被群落和土壤理化性质及酶活性的变化

Changes of Vegetation Community,Soil Physicochemical Properties and Enzyme Activities Under Different Vegetation Restoration Measures

不同植被恢复措施可直接影响植物群落和土壤特性,且植被群落特征与土壤特性之间密切相关。本研究以福建省长汀县历史上水土流失最严重的河田镇为研究区,采用野外植物群落调查法和实验测定法,研究不同恢复措施下植被、土壤以及土壤微生物酶活性等特征,评价其恢复情况。结果表明:1)从植物的群体生长情况来看,植物种类有明显增加,马尾松和芒萁占据优势地位。经过两个措施治理的样地的植物群落生长状况相差不大。在乔木层中,与裸地和风水林相比,不同治理样地植物群落的胸径差异较大,是裸地与风水林的1.72、0.54倍。在灌木层和草本层中,不同治理样地植物群落的冠幅和草层高与裸地和风水林的相比有显著差异。灌木层的冠幅分别是裸地和风水林的3.4、8.7倍。草层高分别为裸地和风水林的3.0倍。2)经过不同措施的植被恢复,土壤养分含量有不同程度的提高,其中有机质含量的最大值和最小值在风水林、裸地分别为22.79±19.32 g·kg^(-1)、3.33±0.25 g·kg^(-1),表明人工恢复措施可以改善土壤结构,但仍需一定的时间才能达到土壤自我生态平衡。另外土壤蔗糖酶活性与过氧化氢酶活性呈增加趋势,土壤微生物量碳(MBC)与氮(MBN)之间不存在显著性差异。3)措施1中的氮含量与土壤蔗糖酶显著正相关(P<0.05),可以看出蔗糖酶对植被群落恢复具有促进作用。措施2治理样地中土壤磷和钾含量与Simpson指数和Margalef指数也呈显著相关作用(P<0.05),表明该措施显著提升了植物物种的丰富度和物种优势性。

Different vegetation restoration measures can directly affect plant communities and soil properties,and the characteristics of vegetation communities and soil properties are closely related.In this research,Hetian Town,the most serious historical soil erosion area in Changting County,Fujian Province,was taken as the study area.The combination of field plant community survey method and experimental measurement method was used to study the vegetation,soil characteristics,soil microbial enzyme activity,and to evaluate the restoration situation under different restoration measures.The results showed that,1)from the overall plant growth,there was a significant increase in plant species,and Pinus massoniana Lamb and Dicranopteris pedata dominated.After the two different treatment,there was little difference in the growth status of the underground plant communities in the samples.In the three layer,the difference in diameter at breast height between the different treatments were 1.72 and 0.54 times greater than those in bare ground and the windswept forests.In the shrub layer and the herb layer,there was a significant difference in the crown width and the height of the grass layer of the different treatment samples compared with that of the bare ground and the windswept forest.The crown width in the shrub layer was 3.4 times that of bare ground and 8.7 times that of windswept forest,respectively.The height of the grass layer was 3.0 times higher than that of bare ground and windswept forest,respectively.2)The soil nutrient content increased to different degrees after different measures of restoration,among which the maximum and minimum values of organic matter content were 22.79±19.32 and 3.33±0.25 g·kg^(-1)in the wind-water forest and bare land,respectively,indicating that the artificial restoration measures can improve the soil structure,but it still needs a certain amount of time to reach the soil self-ecological balance.In addition,soil sucrase activity and catalase activity showed an increasing trend,and there was no significant difference between soil microbial biomass carbon(MBC)and nitrogen(MBN).3)Nitrogen content in Measure 1 was significantly positively correlated with soil sucrase(P<0.05),which can be seen that sucrase is beneficial to the recovery of vegetation communities and has a promotional effect.The soil phosphorus and potassium contents in the sample plots treated by Measure 2 were also significantly correlated with Simpson's index and Margalef's index(P<0.05),indicating that this measure significantly enhanced the richness and species dominance of plant species.