干旱区生态环境知识资源中心(Arid): Applying two remotely-sensed methods for monitoring grazing impacts in the Australian arid zone

Arid

DOI	10.1071/RJ23030
	Applying two remotely-sensed methods for monitoring grazing impacts in the Australian arid zone
	Bastin, Gary; Cowley, Robyn; Friedel, Margaret; Materne, Chris
通讯作者	Bastin, G
来源期刊	RANGELAND JOURNAL
ISSN	1036-9872
EISSN	1834-7541
出版年	2023
卷号	45 期号:4 页码:141-159
英文摘要	Objective monitoring methods that reliably identify grazing impact are required for long-term sustainable management in the arid rangelands. In Australia such methods must contend with highly unpredictable rainfall and large paddocks incorporating spatially complex land types with differing grazing preferences. Retrospective analysis of data collected following very dry and very wet periods removes vegetation dynamics generated by lesser rainfall events and should increase our ability to separate grazing effects from seasonal variability. Two remote-sensing methods were tested for their capacity to quantify trends over 30 years in vegetation-cover dynamics on a pastoral lease in central Australia with a history of heavy grazing. Following destocking by 2002, one section became a conservation reserve and another transitioned to a research station. During drought, the Dynamic Reference Cover Method (DRCM) showed that ground-cover deficit was less negative on both areas towards the end of the study. This improvement was attributable to increased ground cover after removal of grazing, followed by a reduced, but variable, grazing intensity on the research station and the spread of an introduced palatable perennial grass. Ground-cover response following rainfall was highest in 2011. Likewise, increased ground cover meant that the percentage Cover Production Loss (%CPL) index, calculated using grazing gradient methods (GGMs), was considerably less than a decade earlier following similar rainfall. Results from an associated recovery index (R) were inconclusive. Landscape heterogeneity potentially affected calculation of cover deficit using DRCM but, because heterogeneity was stable over time, reported change between dry years reliably indicated a trend owing to grazing. Interpreting trend from successive %CPL values in wet periods was complicated on the research station by altered waterpoint locations being superimposed on pre-existing degradation; however, the method should be effective in large paddocks with stable waterpoint locations. Despite their limitations, both methods can assist in objectively judging the long-term sustainability of grazing practices in contrasting seasonal conditions. The rainfall experienced in Australia's arid rangelands can be so unpredictable that remote-sensing methods depending on regular growing seasons to detect grazing impacts are ineffective. We tested two methods that assess ground cover in the wettest and driest years respectively, across a 32-year period, for detecting trends in impacts. Despite limitations created by spatial variability and small paddocks, the methods provide an objective means of assessing trends in management impacts independent of arid Australia's erratic climate.
英文关键词	cover production loss ground-cover deficit ground-cover response grazing gradients landscape heterogeneity rainfall variability remote sensing stocking rate trend monitoring
类型	Article
语种	英语
收录类别	SCI-E
WOS记录号	WOS:001196526500002
WOS关键词	LAND DEGRADATION ; RAINFALL VARIABILITY ; RECOVERY PROCESSES ; VEGETATION COVER ; GROUND-COVER ; RANGELANDS ; TRENDS
WOS类目	Ecology
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/2XILL650/398214
推荐引用方式 GB/T 7714	Bastin, Gary,Cowley, Robyn,Friedel, Margaret,et al. Applying two remotely-sensed methods for monitoring grazing impacts in the Australian arid zone[J],2023,45(4):141-159.
APA	Bastin, Gary,Cowley, Robyn,Friedel, Margaret,&Materne, Chris.(2023).Applying two remotely-sensed methods for monitoring grazing impacts in the Australian arid zone.RANGELAND JOURNAL,45(4),141-159.
MLA	Bastin, Gary,et al."Applying two remotely-sensed methods for monitoring grazing impacts in the Australian arid zone".RANGELAND JOURNAL 45.4(2023):141-159.