Effects Of Selection Cutting On Carbon Density And Net Primary Productivity Of The Mixed Broadleaved-Korean Pine Forest

Forest is the main body of life support system (terrestrial ecosystem), which be the foundation of the survival and development of human being and sustainable development. Four-fifths of the carbon storage in aboveground and two-fifths of the carbon storage in belowground belongs to forest resources. The subtle variations generate by forest ecosystem carbon, will produce a significant influence on global climate change tendency in the future. As an important part of the carbon cycle, net primary production (NPP) can reflect the change of vegetation structure and function; embody the ecosystem structure and function, meanwhile, the net primary production (NPP) of forest ecological system can also reflect the management level of forest and the complex relationship of mass transfer and energy flow between forest and its surroundings, and makes it become the foundation and the important basis of ecological problem research. Mixed broadleaved-Korean pine forest is the zonal forest vegetation community in the eastern mountainous region of northeast China, also is the representative of temperate mixed forest with unique constructive species and magnificent species diversity. Accurate quantifying forest carbon density and net primary productivity (NPP) is essential for estimating the role of forest ecosystems in global carbon cycle. We measured carbon density and NPP using forest inventory and allometry approaches in virgin broadleaved-Korean pine (Pinus koraiensis) forest and selection cutting forest (which was measured34years after commercial selection cutting), which provide scientific basis for forest management in thisrogion.The results showed that:1) Total carbon density of virgin forest and selection cutting forest were397.95±93.82tC·hm-2and355.61±59.37tC·hm-2, the carbon density of vegetation, detritus and soil accounted was respectively127.25±52.2tC·hm-2and114.88±37.60tC·hm-2,13.09±8.17tC·hm-2and10.17±2.94tC·hm-2、257.6±37.89tC·hm-2and230.57±23.74tC·hm-2, accounting for30.96%,3.11%,65.93%and31.68%,2.93%,65.39%of the total carbon pool. The total carbon density and the proportion of each component had no significant differences in two study sites (P>0.05).2) Total NPP of virgin forest and selection cutting forest were36.27±0.36tC·hm-2·y-1and6.35±0.70tC·hm-2·y-1, tree layer, shrub and herb layer, fine root was respectively3.79±0.40tC·hm-2·y-1and4.18±0.50tC·hm-2·y-1、0.12±0.03tC·hm-2·y-1and0.17±0.01tC·hm-2·y-1、2.36±0,12tC·hm-2·y-1and1.99±0.58tC·hm-2·y-1,accounted for60.31%,1.97%,37.72%and66.11%,1.97%,31.18%of the total NPP, respectively. There were no significant differences in the total NPP and the proportion of each component in two study sites (P>0.05). However, the ratio of needle NPP and broadleaf NPP of virgin forest and selection cutting forest were47.24:52.76and20.48:79.52, respectively, which differed significantly (P <0.05). The results indicated that the carbon density and NPP have recovered to the level before cutting after34years.