Carbon Sequestration Characteristics In Robinia Pseudoacacia Plantation In Loess Hilly Region, China

We studied the dynamic changes and allocation patterns of carbon storage in Robiniapseudoacacia plantation in loess hilly region. In addition, we explored carbon sequestrationrate and potential in R. pseudoacacia plantation ecosystem, and the affecting factors of R.pseudoacacia plantation carbon storage. The main results were as follows:(1) The range carbon contents were387.6–493.4g·kg-1in arbor layer,109.6–462.6g·kg-1in herb and litter layer, and1.7–28.0g·kg-1in soil layer in R. in loess hilly region, respectively.The maximum carbon storage values in arbor layer were44.8Mg·hm-2at the37-year-old R.in Ansai County. The branch was the major carbon pool in arbor layer of R. in each zone,accounted for38.1%–63.4%. The maximum carbon storage values in soil layer were110.9Mg·hm-2at the35-year-old R. in Yichuan County. And the0–50cm soil layer was the majorcarbon pool in the0–100cm soil layer of R. in each zone, accounted for56.7%–69.0%. Themaximum total carbon storage values were167.5Mg·hm-2at the35-year-old R.in Yichuan County. The0–50cm soil layer was the major carbon pool in the0–100cm soillayer of R. in each zone, accounted for56.7%–89.6%.(2) The maximum value were1.61Mg·hm-2·a-1and21.28Mg·hm-2for carbonsequestration rate and potential, in vegetable layer in R. pseudoacacia plantationin Yichuan County. Followed Ansai County, were1.16Mg·hm-2·a-1and16.86Mg·hm-2. Theminimum value were0.48Mg·hm-2·a-1and4.59Mg·hm-2for carbon sequestration rate andpotential, in vegetable layer in R. in Suide County. The research showed that the maximumvalue were2.68Mg·hm-2·a-1and40.08Mg·hm-2for carbon sequestration rate and potential, inR. pseudoacacia plantation ecosystem in Yichuan County. The carbon sequestration rate was2.27Mg·hm-2·a-1, in R. pseudoacacia plantation ecosystem in Suide County, was higher thanthe carbon sequestration rate which was2.15Mg·hm-2·a-1, in R. in Ansai County. But thecarbon sequestration potential was24.63Mg·hm-2, in R. pseudoacacia plantation ecosystemin Suide County, was lower than the carbon sequestration potential which was38.35Mg·hm-2,in R. in Ansai County. Obviously, the carbon sequestration rate and potential in R. pseudoacacia plantation in Yichuan County was better than Ansai and Suide County.(3) The main affecting factors of carbon storage in R. across various vegetation zoneswere different. The main affecting factors R.in Yichuan County were included average contentof soil total phosphorus, biomass in vegetable layer, biomass in litter layer, forest age, altitude,slope, aspect and temperature. The main affecting factors R. in Ansai County were includedaverage content of soil total nitrogen, average soil bulk density, crown density, biomass invegetable layer, rainfall and temperature. And the main affecting factors R.in Suide Countywere included average content of soil total nitrogen, biomass in vegetable layer, biomass inlitter layer, forest age, altitude, slope, aspect and temperature. The results showed thatbiomass in vegetable layer, forest age and temperature were the main affecting factors ofcarbon storage in R. pseudoacacia plantation ecosystem of various vegetation.