干旱区生态环境知识资源中心(Arid): Drivers of change in vegetation and soil in the Gamka Karoo: grazing versus rainfall

Arid

DOI	10.2989/10220119.2021.1947373
	Drivers of change in vegetation and soil in the Gamka Karoo: grazing versus rainfall
	Saayman, N.; Morris, C. D.; Swart, R.; Botha, J. C.
通讯作者	Saayman, N (corresponding author), Western Cape Dept Agr, Directorate Plant Sci, Elsenburg, South Africa.
来源期刊	AFRICAN JOURNAL OF RANGE & FORAGE SCIENCE
ISSN	1022-0119
EISSN	1727-9380
出版年	2021-07
英文摘要	The Gamka Karoo is a low-lying vegetation type in the semi-arid Nama Karoo in the south-western part of South Africa with extensive rangelands used for livestock ranching and wildlife. Although the Nama Karoo is generally resilient to grazing and most responsive to variable rainfall, chronic overstocking, particularly in the driest regions and around water points, could degrade vegetation and soils. The interactive effects of rainfall (MAP) and grazing (stocking rate, percentage overstocking, resting system) on plant species composition and soil chemical characteristics were examined on 36 farms across a regional rainfall gradient (120-300 mm y(-1)) and around water points (n = 3) on farms. Multivariate direct gradient analyses revealed regional species compositional differences were related most strongly to MAP (r = 0.736), but not to grazing, with no MAP x grazing interaction. On a smaller scale, grazing intensity (1/distance from water point) had a weak negative impact on the vegetation (r = 0.36) and soil chemistry (r = 0.49) with nutrient enrichment around water points in paddocks. Our findings suggest that the Karoo is responsive to rainfall, but loosely coupled to grazing. Adaptive management with livestock numbers matched to rainfall and forage supply is recommended to sustain animal production, vegetation and soils.
英文关键词	overgrazing piosphere semi-arid stocking rate
类型	Article ; Early Access
语种	英语
收录类别	SCI-E
WOS记录号	WOS:000673773900001
WOS关键词	PLANT-SPECIES RICHNESS ; SOUTH-AFRICA ; SUBSHRUB/GRASS RANGELAND ; PHYSICAL IMPACT ; SUCCULENT KAROO ; ARID KAROO ; GRADIENTS ; DIVERSITY ; NONEQUILIBRIUM ; MANAGEMENT
WOS类目	Ecology ; Environmental Sciences
WOS研究方向	Environmental Sciences & Ecology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/367547
作者单位	[Saayman, N.; Swart, R.; Botha, J. C.] Western Cape Dept Agr, Directorate Plant Sci, Elsenburg, South Africa; [Morris, C. D.] Univ KwaZulu Natal, Agr Res Council Anim Prod ARC AP, Scottsville, South Africa
推荐引用方式 GB/T 7714	Saayman, N.,Morris, C. D.,Swart, R.,et al. Drivers of change in vegetation and soil in the Gamka Karoo: grazing versus rainfall[J],2021.
APA	Saayman, N.,Morris, C. D.,Swart, R.,&Botha, J. C..(2021).Drivers of change in vegetation and soil in the Gamka Karoo: grazing versus rainfall.AFRICAN JOURNAL OF RANGE & FORAGE SCIENCE.
MLA	Saayman, N.,et al."Drivers of change in vegetation and soil in the Gamka Karoo: grazing versus rainfall".AFRICAN JOURNAL OF RANGE & FORAGE SCIENCE (2021).