Subjects: Biology >> Botany >> Applied botany submitted time 2022-04-29 Cooperative journals: 《广西植物》
Abstract： The Lijiang River Basin covers great variation in altitude, soil and vegetation types. In order to study its soil nutrients and extracellular enzymes activities, we determined soil nutrient contents and activities of several extracellular enzymes (amylase, sucrose, urease, protease and catalase) of the surface soils (0-20 cm) of typical vegetation types (natural forest, bamboo (Phyllostachys pubescens) forest, Pinus massoniana forest, orchard and rice paddy field) with calcareous soils and acid soils in the Lijiang River Basin). The results were as follows: (1) The soils at high altitude had greater total nitrogen (TN), total phosphorus (TP), available phosphorus (AP) contents as well as amylase, sucrose, urease and protease activities, whereas the catalase activity was to the contrary. (2) Compared to the acid soils, the calcareous soils had higher contents of total phosphorus (TP) and available phosphorus (AP). Among the acid soils, vegetation types had greater impact to soil nitrogen and phosphorus content. In general, anthropogenic vegetation resulted in decrease in nitrogen contents and increases in phosphorus content. The nutrients in the calcareous soils had relatively little variation among different vegetation covers. (3) Compared to the natural forest soils, soils from the anthropogenic vegetation had lower nitrogen related enzyme activities; whereas the carbon related enzyme activities was less impacted. The enzymatic stoichiometry revealed that soils of natural forests were nitrogen limited whereas those of anthropogenic vegetation was carbon limited. (4) The results of canonical correspondence analysis (CCA) showed that soil physiochemical properties in the first and second axes could explain 86.56% of the variation of soil enzyme activities with the contribution order of TN>pH>NH4+>AP>TP>NO3-, with the first three as the main impacts. All the above results indicate that acid soils in the Lijiang River Basin has great ecological sensitivity; vegetation changes easily resulted in nutrient imbalance, therefore, in order to improve the sustainable utility of landscape resources of the Lijiang River Basin, special attention should be paid to the conservation of soil nutrients and prevention of the loss of soil organic matter; and this study can provide theoretical base on the scientific conservation and development of local ecosystem.
Hits
Hits
Downloads
Comment