Relationship between soil physicochemical properties and soil enzyme activities in Huixian karst wetland system based on Canonical Correspondence Analysis
Wetland as an important ecological system plays an important role in regulating water and climate change,which was affected by human activities.Therefore,wetland degradation becomes a global phenomenon and the focus of many scientists.Huixian karst wetland system has the research base for comprehensive control of karst ecology and rocky desertification,belonging to original semi-disturbed wetland where in the past 20 years fertilizers have been applied to paddy field and dry land.In order to reveal the relationship between soil physicochemical properties and soil enzyme activities in Huixian karst wetland system,soil samples from three kinds of lands (wetland,paddy field and dry land) were collected.To gain a better understanding of the impact from the human and agricultural activities on the karst wetland system,a suitable evaluation method based on descriptive analysis,correlation analysis and canonical correspondence analysis (CCA) was employed.The highest content of soil organic carbon,total nitrogen,alkali-hydrolyzable nitrogen,cation exchange capacity,exchangeable calcium and exchangeable magnesium appears in the wetland,followed by the paddy field and dry land,respectively;the lowest content of available phosphorus and potassium occurs in the wetland.Therefore,the karst wetland system has an important function in the maintenance of soil carbon sink and nutrition cycle.The content of available phosphorus and potassium in wetland was lower than those in the paddy field and dry land,which was affected by human and agricultural activities.The concentrations of urease,invertase,alkaline phosphatase and cellulose are also quite high in the wetland and show a strong spatial heterogeneity.By analyzing soil factors and soil enzymes confined to wetland and paddy field of the study area,the CCA biplot shows a trend of land degradation in this area,from which it can be seen that the wetland is influenced by human activities.Wetland was first cultivated as paddy field,later it was eventually reclaimed into dry land with the decline of soil natural fertility.Therefore,among these three types of lands,the wetland has a high carbon storage function,while the paddy field has the similar one.If the ecological succession is irreversible,the best way to maintain the ecological environment of wetland system is to protect paddy field as constructed wetland.It is also important to regulate and promote carbon sequestration in karst area.
wetlandsoil organic carbonland use patternsoil enzymecanonical correspondence analysis
国家科技期刊平台
NSTL
万方数据
维普
