干旱区生态环境知识资源中心(Arid): Soil organic carbon and nitrogen in soil physical fractions in woody encroached grassland in South African savannas

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DOI	10.1071/SR20245
	Soil organic carbon and nitrogen in soil physical fractions in woody encroached grassland in South African savannas
	Mureva, Admore; Chivenge, Pauline; Ward, David
通讯作者	Ward, D (corresponding author), Univ KwaZulu Natal, Sch Life Sci, P Bag X01, ZA-3209 Scottsville, South Africa. ; Ward, D (corresponding author), Kent State Univ, Dept Biol Sci, Kent, OH 44242 USA.
来源期刊	SOIL RESEARCH
ISSN	1838-675X
EISSN	1838-6768
出版年	2021
英文摘要	Woody plant encroachment has transformed land-cover patterns in savannas and grasslands throughout the world, with implications for changes in soil organic carbon (SOC) dynamics. However, our understanding of the effects of woody encroachment on SOC is very limited. In a study of pairs of neighbouring, woody encroached and grassland plots along a rainfall gradient (300-1500 mm mean annual precipitation, MAP) in South African savannas, we quantified the changes in SOC and nitrogen pools to a depth of 100 cm, in three soil physical fractions (coarse particulate organic matter, macroaggregates and silt and clay) and bulk soil. The 0-10 cm soil layer of the 1500 mm MAP site lost 26% of SOC stocks due to shrub encroachment. Contrastingly, the 300 and 350 mm MAP sites gained 24% and 27% total SOC, respectively, due to shrub encroachment. In the soil fractions, the largest changes in SOC, ranging within 2.64-464%, were in the coarse particulate organic matter (unprotected organic matter > 250 mu m), and the lowest in the silt and clay fraction (6 32%) across all sites and depths. Soil nitrogen increased across all encroached sites compared with open grasslands, regardless of MAP. For every 1-unit increase in MAP and soil fraction size there was a change of -0.06 and 0.1 SOC (gC/kg soil) in encroached grasslands, respectively. We conclude that shrub-encroached grasslands potentially sequester more C in soils of arid regions than in humid regions. At three of our sites, we were unable to differentiate SOC between encroached and open-grassland soils from bulk soil but could do so from soil fraction analysis. Thus, soil fraction analysis is a more effective way to assess changes in soil C than bulk soil.
英文关键词	grasslands macroaggregates rainfall gradient savanna shrub encroachment soil nitrogen soil organic carbon soil physical fractions
类型	Article ; Early Access
语种	英语
收录类别	SCI-E
WOS记录号	WOS:000629920400001
WOS类目	Soil Science
WOS研究方向	Agriculture
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/352454
作者单位	[Mureva, Admore; Chivenge, Pauline; Ward, David] Univ KwaZulu Natal, Sch Life Sci, P Bag X01, ZA-3209 Scottsville, South Africa; [Mureva, Admore] Bindura Univ Sci Educ, P Bag 1020, Bindura, Zimbabwe; [Chivenge, Pauline] Int Rice Res Inst, DAPO Box 7777, Manila 1301, Philippines; [Ward, David] Kent State Univ, Dept Biol Sci, Kent, OH 44242 USA
推荐引用方式 GB/T 7714	Mureva, Admore,Chivenge, Pauline,Ward, David. Soil organic carbon and nitrogen in soil physical fractions in woody encroached grassland in South African savannas[J],2021.
APA	Mureva, Admore,Chivenge, Pauline,&Ward, David.(2021).Soil organic carbon and nitrogen in soil physical fractions in woody encroached grassland in South African savannas.SOIL RESEARCH.
MLA	Mureva, Admore,et al."Soil organic carbon and nitrogen in soil physical fractions in woody encroached grassland in South African savannas".SOIL RESEARCH (2021).