Study On The Characteristics Of Carbon Storage And Pattern In The Secondary Succession Of Forest Communities In Karst Area

Forest is the largest carbon pool of terrestrial ecosystem, and it aslo the key link of the global carbon cycle, which has important significance for researching in the climate change. Regional forest is often composed of forest patches of different age or stage of succession. The different succession significantly impact on forest carbon trends. A vegetation community of forest determines the structure and function of ecosystem to a large extent. The vegetation succession on carbon absorption and transformation showed different ability. The typical karst rocky desertification vegetation recovery area of Zhongliang Mount is regarded as the selected research object in the study. Combining with the theory and research method of remote sensing process coupling model GLOPEM-CEVSA.According to the different land cover type adjustmented the initial value of model and preferred scheme input parameter, the study considers the effect of soil temperature and humidity and chemical composition of the soil, optimize Q10 values of the study area. By means of model simulated scale patches of forest vegetation net primary productivity、net ecosystem productivity and heterotrophic respiration.In order to explore ecological value of forest restoration project to increase carbon and assess the vegetation types of changes in carbon stocks and space-time variation. It provides a scientific basis and theoretical guidance for the management of karst rocky desertification area. Research results show that:1) The study considers the influence of the amount of soil organic matter, the temperature and humidity of the environment in Zhongliang Mount. In this paper, the Q10 value is localized to the parameters. The results showed that:The mean value of Q10 in 1996, 2001, 2007 and 2013 was 2.106, 2.210, 2.123, and 2.112. The Q10 value of Grassland was the largest, and the standard deviation is relatively small; The Q10 value of Forest Vegetation was relatively small, and the standard deviation was relatively low, The Q10 value of Farmland was the lowest, and the standard deviation was the highest; The Q10 value and standard deviation of the Shrub was between the Forest Vegetation and Farmland.2) The terrestrial ecosystem NPP maximum value appeared in August 1996, forest community Secondary Forest NPP average reached 501.223×107 g C ?month-1, Evergreen Coniferous Forest of the largest floor area ratio, the total NPP reached the 201.625×107g C·month-1. All kinds of vegetation NPP mean size relationship: Broad-Leaved Forest( 73.160 g C/m2·month-1)> Evergreen and Coniferous Forest(64.011 g C/m2·month-1)> Shrub(49.770 g C/m2·month-1)> Grassland(31.280 g C/m2·month-1) > Farmland( 28.430 g C/m2·month-1) > Construction Land(18.069 g C/m2·month-1) > Waters(13.265 g C/m2·month-1).3) The forest community secondary forest system NEP years mean in karst area of Zhongliang Mount is positive because of the performance for atmospheric CO2 carbon sink. It played a significant role in slowing down the carbon source effect of forest ecosystem. NEP negative area are mainly distributed in the mountainous central region, scattered distribution in mountain areas in the west wing, NEP positive area mainly distributed in Zhongliang Mount wings, especially in the east wing of the Zhongliang Mount. From the point of view of average value of terrestrial ecosystem in each vegetation type of unit area of NEP, the size relationship: Broad-Leaved Forest > Evergreen Coniferous Forest > Shrub> Farmland >Grassland> Construction Land > Waters.4) The heterotrophic respiration range in the study area in 2013 was 0.599~2.353 g C/m2?day-1, the average value was 0.602 g C/m2?day-1, the fluctuation range of heterotrophic respiration in 2007 was 0.595~2.35 g C/m2?day-1, the average value of 0.597 g C/m2?day-1, the fluctuation range of heterotrophic respiration in 2001 was 0.586~2.288 g C/m2?day-1, the average value of 0.588 g C/m2?day-1, heterotrophic breathing in 1996 changed between 0.605~2.373 g C/m2?day-1, the average value is 0.607 g C/m2?day-1, soil heterotrophic respiration change with the year is relatively stable, the daily total difference is not obvious. There was a significant positive correlation between soil heterotrophic respiration and temperature that temperature affects the forest ecosystem in the study area soil heterotrophic respiration rate to a certain extent.5) Communities in different successional stages in Zhongliang Mount karst forest region, including Herbaceous Community(Y1), Evergreen Shrub(Y2), Subtropical Bamboo Forest(Y3), Evergreen and Deciduous Broad-Leaved(Y4), Pinus Massonian and Cunninghamia Lanceolata evergreen coniferous forest(Y5), Cypress Evergreen Coniferous Forest(Y6). Forest community natural restoration secondary succession series of NPP values in relation to size is: Y1<Y2<Y6<Y5<Y4,NEP values showed Y1<Y6<Y2<Y5<Y4,with the advance of the natural restoration succession stage, the NEP value showed a trend of first increasing and then decreasing. The fluctuation range of soil heterotrophic respiration in Zhongliang Mount was 1.137~1.498 g C/m2? d-1, Cypress Evergreen Coniferous Forest(Y6) of heterotrophic soil respiration rate was the highest, and Subtropical Bamboo Forest(Y3) soil heterotrophic respiration rate of the lowest. As one of the important forest resources, the bamboo forest has a unique advantage in the forest restoration and enhancement of carbon sink capacity.