title: Spatial variation in the storages and age-related dynamics of forest carbon sequestration in different climate zones-evidence from black locust plantations on the Loess Plateau of China.
abstract: Knowledge about the long-term influences of climate change on the amount of potential carbon (C) sequestration in forest ecosystems, including age-related dynamics, remains unclear. This study used two similar age-sequences of black locust forests (Robinia pseudoacacia L.) in the semi-arid and semi-humid zones of China's Loess Plateau to assess the variation in C stocks and age-related dynamics. Our results demonstrated that black locust forests of the semi-humid zone stored significantly more C than did forests in the semi-arid zone, across the chronosequence (p < 0.001). The C carrying capacity of the plantations was measured at 166.4 Mg C ha-1 (1 Mg = 106 g) in the semi-humid zone, while the semi-arid zone had a capacity of only 79.4 Mg C ha-1. Soil organic C (SOC) increased continuously with stand age in the semi-arid zone (R2 = 0.84, p = 0.010). However, in the semi-humid zone, SOC declined sharply by 47.8% after the initial stage (5 to 10 y). The C stock in trees increased continuously with stand age in the semi-humid zone (R2 = 0.83, p = 0.011), yet in the semi-arid zone, it decreased dramatically from 43.0 Mg C ha-1 to 28.4 Mg C ha-1 during the old forest stage (38 to 56 y). The shift from being a net C sink to a net C source occurred at the initial stage in the semi-humid zone versus at the old forest stage in the semi-arid zone after reforestation. Surprisingly, with the exception of the initial and later stages (55 y), the patterns of C allocation among trees, soils, understory and litter were not statistically different between the two climate zones. Our results suggest that climate factors can alter the potential amount and age-related dynamics of forest C sequestration.
authors: College of Forestry, Northwest Agriculture and Forestry University, Yang Ling, Shaanxi, China.
authors: Taijun
authors: T
authors: Li
authors: College of Forestry, Northwest Agriculture and Forestry University, Yang Ling, Shaanxi, China.
authors: Bowen
authors: B
authors: Ren
authors: College of veterinary medicine, Northwest Agriculture and Forestry University, Yang Ling, Shaanxi, China.
authors: Dahui
authors: D
authors: Wang
authors: College of Forestry, Northwest Agriculture and Forestry University, Yang Ling, Shaanxi, China; Institute of Water and Soil Conservation, Chinese Academy of Sciences, Yang Ling, Shaanxi, China.
authors: Guobin
authors: G
authors: Liu
mesh_terms: D057965:Carbon Sequestration; D002980:Climate; D057231:Climate Change; D065928:Forests; D006813:Humidity; D031301:Robinia / Q000378:metabolism*; D013997:Time Factors