干旱区生态环境知识资源中心(Arid): A comparative assessment of water use by Acacia longifolia invasions occurring on hillslopes and riparian zones in the Cape Agulhas region of South Africa

Arid

DOI	10.1016/j.pce.2018.10.002
	A comparative assessment of water use by Acacia longifolia invasions occurring on hillslopes and riparian zones in the Cape Agulhas region of South Africa
	Mkunyana, Y. P.; Mazvimavi, D.; Dzikiti, S.; Ntshidi, Z.
通讯作者	Mkunyana, YP (corresponding author), Univ Western Cape, Inst Water Studies, Bellville, South Africa. ; Mkunyana, YP (corresponding author), Univ Western Cape, Dept Earth Sci, Bellville, South Africa.
会议名称	18th WaterNet/WARFSA/GWPSA Symposium on Integrated Water Resources Development and Management - Innovative Technological Advances for Water Security in Eastern and Southern Africa
会议日期	OCT 25-27, 2017
会议地点	Swakopmund, NAMIBIA
英文摘要	The detrimental impacts of invasive alien plants on ecosystems and water resources have raised concerns in arid and semi-arid countries like South Africa where the average precipitation is approximately 500 mm/yr, which is below the world average of around 860 mm/yr. Several studies have examined the effects of invasive alien plants such as the Australian Acacias on the water resources. However, few studies have quantified the differences in water use between hillslope and riparian Acacia longifolia invasions. A. longifolia is one of the aggressive invader species in South Africa even on hillslopes that contribute substantially to runoff generation. Therefore, the encroachment of invasive alien plants has the potential to reduce runoff, thereby adversely affecting the available water downstream. This paper aims to; 1) compare transpiration rates of A. longifolia growing on hillslopes and along riparian areas, 2) establish the key drivers for water use by this species, and 3) estimate the hydrological impacts of the invasions at the catchment scale in the Heuningnes catchment, in the Western Cape Province of South Africa. Transpiration by the trees was measured using the heat pulse velocity sap flow method. Automatic weather stations and soil moisture sensors were used to monitor weather and soil water content variations at each site. The results showed that, at the stand level the riparian A. longifolia transpired two times more water ( similar to 596 mm/yr) than on the hillslope (similar to 242 mm/yr). During years with above average rainfall, the water use rates by the invasions was estimated to be similar to 579 mm/yr on the hillslope and could be as much as similar to 1348 mm/yr at the riparian site. Thus, the hypothesis that riparian trees use more water than invasions on non-riparian areas was accepted in this study. At the catchment scale (740 km(2)), the estimated water use by the invasions was 20.5 Mm(3). Clearing of all the invasions in the study catchment is likely to make 17 Mm(3)/yr of water available. Hence the clearing of A. longifolia along the riparian corridors should be prioritised as this will lead to water savings at the catchment scale.
英文关键词	Microclimate Profile soil moisture Sap flow Transpiration Western cape
来源出版物	PHYSICS AND CHEMISTRY OF THE EARTH
ISSN	1474-7065
EISSN	1873-5193
出版年	2019
卷号	112
页码	255-264
出版者	PERGAMON-ELSEVIER SCIENCE LTD
类型	Article; Proceedings Paper
语种	英语
收录类别	CPCI-S
WOS记录号	WOS:000491169000028
WOS关键词	ALIEN PLANTS ; WESTERN CAPE ; USE DYNAMICS ; TREES ; CATCHMENT ; RIVER ; GROUNDWATER ; VEGETATION ; REMOVAL ; IMPACTS
WOS类目	Geosciences, Multidisciplinary ; Meteorology & Atmospheric Sciences ; Water Resources
WOS研究方向	Geology ; Meteorology & Atmospheric Sciences ; Water Resources
资源类型	会议论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/369965
作者单位	[Mkunyana, Y. P.; Mazvimavi, D.; Ntshidi, Z.] Univ Western Cape, Inst Water Studies, Bellville, South Africa; [Mkunyana, Y. P.; Mazvimavi, D.; Ntshidi, Z.] Univ Western Cape, Dept Earth Sci, Bellville, South Africa; [Dzikiti, S.; Ntshidi, Z.] CSIR, Nat Resources & Environm, Stellenbosch, South Africa
推荐引用方式 GB/T 7714	Mkunyana, Y. P.,Mazvimavi, D.,Dzikiti, S.,et al. A comparative assessment of water use by Acacia longifolia invasions occurring on hillslopes and riparian zones in the Cape Agulhas region of South Africa[C]:PERGAMON-ELSEVIER SCIENCE LTD,2019:255-264.