Carbon Storage Of Pinus Tabulaeformis Plantation At Different Stand Ages In Pingquan Of Hebei Province

Forest gives full play to the function of carbon sink, which is an effective measure to reduce the atmospheric CO2concentration and alleviate the greenhouse effect. As carbon storage is an important parameter in forest carbon sink function, it is significant to research carbon storage in forest ecosystem. At present, static research in forest carbon storage is so much, but dynamic process research is little. In this paper12sample plots of Pinus tabulaeformis plantation at30-,40-and50-year-old stand ages in Pingquan of Hebei Province were researched. Pinus tabulaeformis plantation and organs of Pinus tabulaeformis got overall and systematic classification, and biomass in every component was determined with biomass method, and carbon content rate in every component was determined with potassium dichromate concentrated sulfuric acid method. Then carbon storage in Pinus tabulaeformis plantation was evaluated accurately, and its change law in time series and spatial distribution pattern were explored. Finally we can evaluate carbon sink function in Pinus tabulaeformis plantation accurately and provide the theory basis to forest management measures for the sake of enhancement in forest carbon sink. Main results are as following:(1) Forest biomass increased obviously from half-mature stand to mature stand. Forest biomass in the30-,40-and50-year-old stands were25.88t-hm-2,49.89t-hm-2,80.11t-hm-2. Tree layer was the main component of forest biomass.(2) Single-tree biomass increased obviously from half-mature stand to mature stand. Single-tree biomass in the30-,40-and50-year-old stands were11.61kg,26.15kg,100.73kg. The order of biomass distribution in the main organs of Pinus tabulaeformis was truck> branch> root> leaf> bark> cone. The root-shoot ratio of Pinus tabulaeformis was0.18. In the canopy layer of Pinus tabulaeformis, dead branch mostly distributed in the lower layer, live branch mostly distributed in the lower and middle layer, leaf and cone both mostly distributed in the middle and upper layer.(3) Forest carbon storage increased obviously from half-mature stand to mature stand. Forest. carbon storage in the30-,40-and50-year-old stands were44.99t-hm-2,69.02thm-2,100.99t-hm-2. The order of carbon storage distribution in the stand was soil layer> tree layer> litter layer> understory vegetation layer. Soil layer and tree layer were the main components of forest carbon pool, and tree layer played an important role in forest carbon sink. The ability of forest carbon sink from half-mature stand to mature stand improved continuously.(4) Single-tree carbon storage increased obviously from half-mature stand to mature stand. Single-tree carbon storage in the30-,40-and50-year-old stands were6.00kg,14.51kg,54.89kg. The order of carbon storage distribution in the main organs of Pinus tabulaeformis was truck> root> branch> leaf> bark> cone. The mean carbon content rate of Pinus tabulaeformis was54.34%. The ability of carbon sink of Pinus tabulaeformis from half-mature stand to mature stand improved continuously.(5) Carbon storage of understory vegetation layer first increased and then decreased from half-mature stand to mature stand. Carbon storage of understory vegetation layer in the30-,40-and50-year-old stands were0.13t-hm-2,0.12t-hm-2,0.54t-hm-2. The mean carbon content rate of understory vegetation layer was29.25%. Litter carbon storage first decreased and then increased from half-mature stand to mature stand. Litter carbon storage in the30-,40-and50-year-old stands were0.61t-hm-2,0.92t-hm-2,0.81t-hm-2. The mean carbon content rate of litter layer was62.24%.(6) Soil carbon storage increased from half-mature stand to mature stand. Soil carbon storage in the30-,40-and50-year-old stands were31.14thm-2,40.56t-hm-2,56.94t-hm-2. The mean carbon content rate of soil layer was0.76%. The ability of soil carbon sink from half-mature stand to mature stand improved continuously.