干旱区生态环境知识资源中心(Arid): Soil characteristics within vegetation patches are sensitive indicators of savanna rangeland degradation in central Namibia

Arid

DOI	10.1016/j.geodrs.2024.e00771
	Soil characteristics within vegetation patches are sensitive indicators of savanna rangeland degradation in central Namibia
	Zimmer, Katrin; Amputu, Vistorina; Schwarz, Lisa-Maricia; Linstaedter, Anja; Sandhage-Hofmann, Alexandra
通讯作者	Zimmer, K
来源期刊	GEODERMA REGIONAL
ISSN	2352-0094
出版年	2024
卷号	36
英文摘要	Savanna rangelands are threatened by increased grazing pressure, with the risk of desertification and woody plant encroachment. In this context, sensitive early -warning indicators for irreversible shifts toward degraded rangelands are urgently needed. We hypothesize that soil properties, in particular soil organic carbon (SOC) and carbon isotopes (delta 13C) are suitable to detect degradation in different land management systems. We conducted a natural experiment on arid savanna rangelands on Arenosols in Namibia. As treatments, we considered two land management systems (freehold farms with rotational grazing and systematic bush thinning, and communal rangelands with free grazing without systematic bush thinning), with different grazing intensities (grazing gradients), and four vegetation patch types (dominance of bare soil, annual plants, perennial grasses, or woody plants) with four replications per land management system. Clay was considered a system -inherent confounder. SOC stocks were lower on communal rangelands (8.2 +/- 2.8 Mg ha -1) than on freehold farms (9.7 +/- 2.6 Mg ha -1). Besides clay content, SOC stocks correlated with perennial grass cover (r = 0.6) in freehold farms, and with woody plant cover (r = 0.54) in communal rangelands. delta 13C values were higher by 2.15 parts per thousand on freehold farms, indicating greater origin of C4 grass derived SOC. Distance to the nearest water point - as an estimate of local grazing intensity - had a small effect on SOC stocks compared to clay. SOC was a sensitive degradation indicator in savanna rangelands when considered together with the patchy character of savanna vegetation. Under current land management and tenure, communal rangelands faced higher degradation threats than freehold farms, but were also more vulnerable due to lower clay contents.
英文关键词	Arenosols Arid savanna Soil organic carbon Carbon isotopes Land tenure Rangeland management Ecological thresholds
类型	Article
语种	英语
开放获取类型	hybrid
收录类别	SCI-E
WOS记录号	WOS:001173922000001
WOS关键词	ORGANIC-CARBON ; GRAZING GRADIENTS ; FREEHOLD FARMLANDS ; ENCROACHMENT ; MANAGEMENT ; INTENSITY ; DRIVERS ; IMPACTS ; ECOSYSTEMS ; FRACTIONS
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/2XILL650/403928
推荐引用方式 GB/T 7714	Zimmer, Katrin,Amputu, Vistorina,Schwarz, Lisa-Maricia,et al. Soil characteristics within vegetation patches are sensitive indicators of savanna rangeland degradation in central Namibia[J],2024,36.
APA	Zimmer, Katrin,Amputu, Vistorina,Schwarz, Lisa-Maricia,Linstaedter, Anja,&Sandhage-Hofmann, Alexandra.(2024).Soil characteristics within vegetation patches are sensitive indicators of savanna rangeland degradation in central Namibia.GEODERMA REGIONAL,36.
MLA	Zimmer, Katrin,et al."Soil characteristics within vegetation patches are sensitive indicators of savanna rangeland degradation in central Namibia".GEODERMA REGIONAL 36(2024).