The Impact To Carbon Stocks Of Artificial Pine Forest Ecosystems With Different Management Measures

The increasing of atmospheric CO₂ concentration and temperature as the main characteristics of global climate change,which profoundly changing the landing ecosystem structure and functions,threatening to the survival of human health and safety, the governments and scientists become to the most significant concern about the global ecological and environmental science issues so.To reduce the increasing of atmospheric CO₂ concentration,the "Kyoto Protocol" clearly putting forward that by the effective management,the carbon sequestration capacity of terrestrial ecosystems can be increased, and the effectiveness of management can partially offset the carbon emission reduction share of the country which committing to emission reduction mandate.China is the world's largest area of the plantation,not only the increase in plantations can improve China's ecological environment,but also in favor of fixing the atmospheric CO₂.Masson pines was one of the most important pioneer reforestation species of the Sichuan Province and the whole China's,the research of carbon stocks in artificial pine forest was large at present,but including Sichuan,the western region in this regard is still relatively limited, and the literature on the relationship of carbon stocks and management in artificial pine forest is lacking also.The carbon stocks and its distribution characteristics of artificial pine forest ecosystem in different management measures were studied in this paper,the results show that:(1) Tree species composition took different degrees of impacts to carbon stocks in artificial pine forest ecosystem and its all layers.Compared to pure pine forest(128.3 MgC·hm^-2),the carbon stocks of pine and broad-leaved mixed forest ecosystem grow substantially,its growth amounted to 16.9 MgC·hm^-2,but the carbon stocks of pine and fir mixed forest ecosystem was only 132.3 MgC·hm^-2,showed unobvious trend of growth. In pine～broad-leaved and pine～fir mixed forest ecosystems,the carbon stocks of arbor layer were 50.4 MgC·hm^-2 and 45.4 MgC·hm^-2,both below than pure pine forest(53.8 MgC·hm^-2),it mainly because of the shorter updated mixed species,which is also a important reasons for the unobvious growth of carbon stocks in pine and fir mixed forest ecosystem,relative to arbor layer,the carbon stocks of shrub and litter layer of pine～ broad-leaved and pine～fir mixed forest were higher than pure pine forest(2.5MgC·hm^-2), which amount to 7.5 MgC·hm^-2 and 7.1 MgC·hm^-2 respectively,and the carbon stock of soil layer was also higher than pure pine forest(72.0 MgC·hm^-2),its growth amounted to 15.3MgC·hm^-2 and 7.8MgC·hm^-2.Choose appropriate tree species to construct artificial mixed forest,would played an important role to increased the carbon sequestration of plantation ecosystems(2) Exclusion management effective enhanced the carbon accumulation capacity of artificial pine forest ecosystem.After exclusion,the carbon stocks of artificial pine forest ecosystem grow substantially,compared to comparison(128.3 MgC·hm^-2),the carbon stocks of pure pine forest ecosystem was increased of 35.2 MgC·hm^-2,and the pine～broad-leaved mixed forest ecosystem was also increased of 32.5MgC·hm^-2 compared to comparison(139.6MgC·hm^-2).In pure pine forest and pine～broad-leaved mixed forest ecosystems,the carbon stocks of arbor layer were 70.5MgC·hm^-2 and 67.4MgC·hm^-2, respectively increased of 20.1MgC·hm^-2 and 17.6MgC·hm^-2 compared to comparison,the carbon stocks of shrub and litter layer were 6.8MgC·hm^-2 and 11.7MgC·hm^-2,respectively increased of 4.4MgC·hm^-2 and 5.0MgC·hm^-2 compared to comparison,the carbon stocks of soil layer were 82.8MgC·hm^-2 and 93.0MgC·hm^-2,respectively increased of 10.7MgC·hm^-2 and 9.9MgC·hm^-2 compared to comparison.(3) The management of compound planting patterns would be one of the effective ways to increase carbon "sink" of plantations.Compared to pure pine forest (129.5MgC·hm^-2),the carbon stocks of pine～tea and pine～bamboo compound planting patterns forest ecosystems grow substantially,the growth amounted to 27.7 MgC·hm^-2 and 35.4 MgC·hm^-2 respectively.In the pine～tea compound planting patterns forest ecosystems,the carbon stocks of arbor and soil layer were 66.4 MgC·hm^-2 and 89.5MgC·hm^-2,increased of 10.6MgC·hm^-2 and 18.5MgC·hm^-2 compared to pure pine forest,but for the impacts of human activities,the carbon stocks of shrub and litter layer decreased of 1.4 MgC·hm^-2,were only 1.3MgC·hm^-2.However,compared to pure pine forest,the carbon stocks in all layers of pine～bamboo compound planting patterns forest ecosystems grow obviously,the growth amounted to 13.7 MgC·hm^-2(arbor layer),3.0 MgC·hm^-2(shrub and litter layer) and 17.7 MgC·hm^-2(soil layer).(4) The management led the artificial pine forest become to the carbon "sink" in atmosphere.The "sink" created by different management measures were 1.7～9.4 MgC·hm^-2·a^-1,corresponding,the ecological value up to 255～1410 yuan·hm^-2·a^-1,and through management of compound planting patterns,the artificial pine forest would got additional economic benefits.So,try to carry out various forms of management activities to plantations,would be positive to increase carbon "sink",ecological and economic value of plantations,enhance the use standard of plantations,and increase the income of the farmers.