Carbon storage in biomass, litter, and soil of different plantations in a semiarid temperate region of northwest China.

摘要

Context: A large area of abandoned land in the semiarid temperate region of China has been converted into plantations over the past decades. However, little information is available about the ecosystem C storage in different plantations. Aim and methods: Our objective was to estimate the C storage in biomass, litter, and soil of four different plantations (monospecific stands of Larix gmelinii, Pinus tabuliformis, Picea crassifolia, and Populus simonii). Tree component biomass was estimated using allometric equations. The biomasses of understory vegetation and litter were determined by harvesting all the components. C fractions of plant, litter, and soil were measured. Results: The ecosystem C storage were as follows: Picea crassifolia (469 t C/ha) > Larix gmelinii (375 t C/ha), Populus simonii (330 t C/ha) > Pinus tabuliformis (281 t C/ha) (P<0.05), 59.5-91.1% of which was in the soil. The highest tree and understory C storage were found in the plantation of Pinus tabuliformis (247 t/ha) and Larix gmelinii (1.2 t/ha) respectively. The difference in tree C fraction was significant among tree components (P<0.05), following the order: leaf > branch > trunk > root. The highest soil C (SC) was stored in Picea crassifolia plantation (411 t C/ha), while Populus simonii plantation had a higher SC sequestration rate than others. Conclusion: C storage and distribution varied among different plantation ecosystems. Coniferous forests had a higher live biomass and litter C storage. Broadleaf forests had considerable SC sequestration potential after 40 years establishment.