Study On Nutrient Dynamics And Enzyme Activity Of Forest Ecosystem In Changan Mountain Park,Fuzhou

The ecological environment is increasingly serious in the city,forest ecosystem plays an irreplaceable ecological,environmental and economic benefits,thus the nutrient cycling and the health status and development trend of forest ecosystem in the city more and more concern.Based on the Fuzhou city Cangshan District Changan mountain Forest Park community structure,species diversity,litter and forest surface soil nutrient and enzyme activity characteristics,litter decomposition and dynamic change of enzyme activity in the decomposition process are analyzed,in order to provide the basic data and scientific basis for reveal the status and influencing factors of nutrient cycling in forest ecosystem of the city and scientific and rational management and utilization of city forest,give full play to the benefits.The results of the study show that:1)The forest flora of Changan mountain is mainly tropical,which is in line with the subtropical climate zone.In the community structure,young individuals accounted for a large proportion.Biodiversity studies also show that the shrub layer(including tree seedlings)has the largest biodiversity.It shows that the forest community in Changan is in an overall growth pattern and can be sustained and healthy development.2)Within one year of monitoring,in the nutrient of the existing litter layer,the organic C content increased slightly in summer,but the total N content decreased slightly in summer.The total P content of fresh litter was higher than that in semi decomposed litter.In the enzyme activity in the litter layer,the activity of AP mainly within 1000 nmol·h-1·g-1,βG,CBH activity in half decomposition also showed higher levels of litter,NAG is higher in fresh litter,the activity of Perox in 2 kinds of litter type were lower than 50 nmol·h-1·g-1.The change trend is more consistent,the activity of PhOx is mainly below 4 nmol·h-1·g-1.Extracellular enzyme activity related to nutrient content and type,and soil enzyme activities were higher than fresh and semi decomposed litters.3)Under the condition of net method,Acacia confusa,Cinnamomum camphora and Pinus massoniana leaf litter decomposition half-life is 1 a,the basic decomposition process of organic C,total N,total P with decomposition time release,the release amount of K tends to be stable after 124 d,similar to those of the similar forest.Enzyme activities showed that the activities of enzymes in the 3 types of litters were different,and the activities of soil enzymes were larger than those of litters.Although Changan mountain Forest Park results of the level of nutrient cycling of forest was similar to the same type of community,maintain the existing park management level is conducive to the development of the community,but the combination of the park area is small,the stand structure is single,the soil nutrient content was low and disturbed many other issues,the forest ecosystem health should still be sustained attention and timely supply of nutrients.