Knowledge Resource Center for Ecological Environment in Arid Area
DOI | 10.1111/j.1365-2664.2012.02157.x |
Shifting thresholds and changing degradation patterns: climate change effects on the simulated long-term response of a semi-arid savanna to grazing | |
Lohmann, Dirk1; Tietjen, Britta2,3; Blaum, Niels1; Joubert, David F.4; Jeltsch, Florian1 | |
通讯作者 | Lohmann, Dirk |
来源期刊 | JOURNAL OF APPLIED ECOLOGY
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ISSN | 0021-8901 |
出版年 | 2012 |
卷号 | 49期号:4页码:814-823 |
英文摘要 | 1. The complex, nonlinear response of dryland systems to grazing and climatic variations is a challenge to management of these lands. Predicted climatic changes will impact the desertification of drylands under domestic livestock production. Consequently, there is an urgent need to understand the response of drylands to grazing under climate change. 2. We enhanced and parameterized an ecohydrological savanna model to assess the impacts of a range of climate change scenarios on the response of a semi-arid African savanna to grazing. We focused on the effects of temperature and CO2 level increase in combination with changes in inter- and intra-annual precipitation patterns on the long-term dynamics of three major plant functional types. 3. We found that the capacity of the savanna to sustain livestock grazing was strongly influenced by climate change. Increased mean annual precipitation and changes in intra-annual precipitation pattern have the potential to slightly increase carrying capacities of the system. In contrast, decreased precipitation, higher interannual variation and temperature increase are leading to a severe decline of carrying capacities owing to losses of the perennial grass biomass. 4. Semi-arid rangelands will be at lower risk of shrub encroachment and encroachment will be less intense under future climatic conditions. This finding holds in spite of elevated levels of atmospheric CO2 and irrespective of changes in precipitation pattern, because of the drought sensitivity of germination and establishment of encroaching species. 5. Synthesis and applications. Changes in livestock carrying capacities, both positive and negative, mainly depend on the highly uncertain future rainfall conditions. However, independent of the specific changes, shrub encroachment becomes less likely and in many cases less severe. Thus, managers of semi-arid rangelands should shift their focus from woody vegetation towards perennial grass species as indicators for rangeland degradation. Furthermore, the resulting reduced competition from woody vegetation has the potential to facilitate ecosystem restoration measures such as re-introduction of desirable plant species that are only little promising or infeasible under current climatic conditions. On a global scale, the reductions in standing biomass resulting from altered degradation dynamics of semi-arid rangelands can have negative impacts on carbon sequestration. |
英文关键词 | CO2 increase demographic bottleneck ecohydrology grid-based simulation model livestock precipitation pattern savanna resilience shrub encroachment soil moisture sustainable rangeland management |
类型 | Article |
语种 | 英语 |
国家 | Germany ; Namibia |
收录类别 | SCI-E |
WOS记录号 | WOS:000306477000008 |
WOS关键词 | TREE-GRASS COEXISTENCE ; ATMOSPHERIC CO2 ; ACACIA-MELLIFERA ; SOUTH-AFRICA ; LAND-USE ; VEGETATION ; DYNAMICS ; RANGELANDS ; ENCROACHMENT ; ECOSYSTEMS |
WOS类目 | Biodiversity Conservation ; Ecology |
WOS研究方向 | Biodiversity & Conservation ; Environmental Sciences & Ecology |
资源类型 | 期刊论文 |
条目标识符 | http://119.78.100.177/qdio/handle/2XILL650/173140 |
作者单位 | 1.Univ Potsdam, D-14469 Potsdam, Germany; 2.Free Univ Berlin, Inst Biol, D-14195 Berlin, Germany; 3.Potsdam Inst Climate Impact Res PIK, D-14412 Potsdam, Germany; 4.Polytech Namibia, Sch Nat Resource Management & Tourism, Windhoek, Namibia |
推荐引用方式 GB/T 7714 | Lohmann, Dirk,Tietjen, Britta,Blaum, Niels,et al. Shifting thresholds and changing degradation patterns: climate change effects on the simulated long-term response of a semi-arid savanna to grazing[J],2012,49(4):814-823. |
APA | Lohmann, Dirk,Tietjen, Britta,Blaum, Niels,Joubert, David F.,&Jeltsch, Florian.(2012).Shifting thresholds and changing degradation patterns: climate change effects on the simulated long-term response of a semi-arid savanna to grazing.JOURNAL OF APPLIED ECOLOGY,49(4),814-823. |
MLA | Lohmann, Dirk,et al."Shifting thresholds and changing degradation patterns: climate change effects on the simulated long-term response of a semi-arid savanna to grazing".JOURNAL OF APPLIED ECOLOGY 49.4(2012):814-823. |
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