Effects Of Slash Burning On Ecosystem Long-term Productivity Of Chinese Fir Plantation

Chinese fir(Cunninghamia lanceolata(Lamb.)Hook.)In southern China's most important fast-growing plantation species,has long been planted fir plantation stocks led to a significant decline.Current research reports on fir trees planted in soil productivity and more,many scholars have pointed fir plantation unreasonable measures led to a decline in productivity stand and soil physical,chemical nature of the major external deterioration.Therefore the use of reasonable and effective management measures to solve the fir plantations in the production process of important issues.Southern forest before planting is often used to clean up the mountain woodland refining,refining the mountain is more economical and convenient ground clearance,short bowel after slash burning fat can increase the role of plantation survival rate,the short term can promote the growth of Cunninghamia.But Slash cleanup approach will lead to woodland soil erosion,soil properties deteriorate,environmental degradation and other issues,is not conducive to long-term productivity of plantations maintained.Some scholars believe that five years after the slash burning of forest vegetation cover increases,reducing the amount of forest soil erosion,improve the ecological environment will not cause too much impact on the long-term productivity of plantations.Slash impact on Chinese fir plantations on basic research study only young forest stage,basic research is not more than 10 years of years,which can not effectively evaluate the long-term impact on refining the mountain fir plantations.In view of this,the study of artificial mature forest for the study,comparative study of Chinese fir or not slash burning plantation,forest in Youxi County,Fujian Institute of Forestry siltstone parent materials mountain fir forest and Ondo test granite parent material fir impact of vegetation,soil fertility and other indicators,analysis of slash burning fir forest ecosystems,long-term impact of the law.The main findings are as follows:(1)Slash affect the results of the granite parent material fir plantations and siltstone parent materials more consistent fir plantation.After refining the mountain before planting treated fir plantation test cell average tree height,mean diameter,the average volume was less than before planting without Slash treated fir forest,and the difference was significant(P<0.05).Fir woodland area not slash burning biomass is also greater than Slash handling cell,where the dry biomass and leaf area of slash burning difference was significant(P<0.05).Slash handling cell fir tree height,diameter annual increment is less refined mountain area also decreased rapidly,did not show good long-term growth capacity.Tree layer nutrient content and the carbon content in the mountains with no refining refining processing small difference between the mountains,and nutrient accumulation of the more obvious differences,and refining the forest branches,roots,leaves and other organs of each nutrient accumulation of points and no differences were refining mountains more obvious.Distribution ratio of the different treatment of various organs stand nutrients also had some differences.(2)Slash burning forest understory vegetation species richness to the mountains just above points are not refining,but not refining forest understory vegetation biomass points,etc.cover more than refining forest land and forest land biomass and refining the difference was significant between.Nutrient accumulation of forest land without refining understory vegetation is also slightly higher than refining forest land.(3)Different levels of soil bulk density greater than refining forest land not refining forest land,its natural moisture content,water holding capacity,capillary water,substantially below field capacity refining forest land,forest land without refining surface soil aeration performance superior refining forest land.Differences in soil moisture different physical properties are obvious differences in the surface,Slash has little effect on the physical properties of deep soil moisture.In two experimental forest land to non-refining each soil layer pH values were greater than refining the mountains,the refining more acidic forest soils,soil acidification phenomenon is more serious,but also hindered the growth of Chinese fir.Chinese fir soil total nutrient content increased with soil depth fundamental decline.Refining forest soil total N,total P content of less than non-burning forests,the differences are not large refining and forest land,and the difference in the surface level were significant(P<0.05),while soil total K,C content in whole Slash Slash and no obvious difference between treatment.Available nutrient content of the soil decreases with the increase.Hydrolysis refining forest soil nitrogen,phosphorus content is substantially less than the non-burning forest land,and the hydrolysis of the nitrogen content in the soil and not mixing between the mountains to reach the differences were significant(P<0.05).The potassium in the mountains with no refining treatments was smaller.(4)In different soil parent material test fir forest,not the more refining refining forest land forest land have shown better long-term productivity,stand productivity caused mainly due to differences Slash destroy the forest environment,so reducing forest coverage community structure is destroyed,resulting in deterioration of soil physical and chemical properties,long-term erosion of the entire ecosystem nutrient deprivation.So before planting clean up logging residues should not try to use slash burning mode,slash burning of forest land in order to maintain long-term productivity,preventing forest because every generation before planting both Slash gradually lost productivity,relevant laws and regulations should be enacted as soon as possible,improve the compensation mechanism active promotion of non-burning mountain afforestation,reforestation before Slash can not effectively prevent soil erosion,maintain the stability of ecosystems to ensure long-term supply of forest soil nutrients in order to maintain long-term productivity of Chinese fir plantation ecosystem.