Afforestation impacts microbial biomass and its natural (13)C and (15)N abundance in soil aggregates in central China.
We investigated soil microbial biomass and its natural abundance of δ(13)C and δ(15)N in aggregates (>2000μm, 250-2000μm, 53-250μm and <53μm) of afforested (implementing woodland and shrubland plantations) soils, adjacent croplands and open area (i.e., control) in the Danjiangkou Reservoir area of central China. The afforested soils averaged higher microbial biomass carbon (MBC) and nitrogen (MBN) levels in all aggregates than in open area and cropland, with higher microbial biomass in micro-aggregates (<250μm) than in macro-aggregates (>2000μm). The δ(13)C of soil microbial biomass was more enriched in woodland soils than in other land use types, while δ(15)N of soil microbial biomass was more enriched compared with that of organic soil in all land use types. The δ(13)C and δ(15)N of microbial biomass were positively correlated with the δ(13)C and δ(15)N of organic soil across aggregates and land use types, whereas the (13)C and (15)N enrichment of microbial biomass exhibited linear decreases with the corresponding C:N ratio of organic soil. Our results suggest that shifts in the natural (13)C and (15)N abundance of microbial biomass reflect changes in the stabilization and turnover of soil organic matter (SOM) and thereby imply that afforestation can greatly impact SOM accumulation over the long-term.
Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, PR China.
Junjun
J
Wu
Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, PR China.
Qian
Q
Zhang
Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, PR China.
Fan
F
Yang
Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, PR China.
Yao
Y
Lei
Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, PR China.
Quanfa
Q
Zhang
Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, PR China. Electronic address: xlcheng@fudan.edu.cn.
Xiaoli
X
Cheng
D001419:Bacteria / Q000378:metabolism; D018533:Biomass; D002247:Carbon Isotopes / Q000032:analysis*; D002681:China; D003247:Conservation of Natural Resources; D016468:Forestry; D065928:Forests; D009587:Nitrogen Isotopes / Q000032:analysis*; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology
D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; C000615243:Nitrogen-15; D012987:Soil; C000615229:Carbon-13
Afforestation; Microbial biomass; Natural abundance of (13)C and (15)N; Soil aggregates