Knowledge Resource Center for Ecological Environment in Arid Area
DOI | 10.1007/s10021-010-9384-8 |
Biotic and Abiotic Changes in Ecosystem Structure over a Shrub-Encroachment Gradient in the Southwestern USA | |
Turnbull, Laura1; Wainwright, John2; Brazier, Richard E.3; Bol, Roland4 | |
通讯作者 | Turnbull, Laura |
来源期刊 | ECOSYSTEMS
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ISSN | 1432-9840 |
出版年 | 2010 |
卷号 | 13期号:8页码:1239-1255 |
英文摘要 | In this study, we investigate changes in ecosystem structure that occur over a gradient of land-degradation in the southwestern USA, where shrubs are encroaching into native grassland. We evaluate a conceptual model which posits that the development of biotic and abiotic structural connectivity is due to ecogeomorphic feedbacks. Three hypotheses are evaluated: 1. Over the shrub-encroachment gradient, the difference in soil properties under each surface-cover type will change non-linearly, becoming increasingly different; 2. There will be a reduction in vegetation cover and an increase in vegetation-patch size that is concurrent with an increase in the spatial heterogeneity of soil properties over the shrub-encroachment gradient; and 3. Over the shrub-encroachment gradient, the range at which soil properties are autocorrelated will progressively exceed the range at which vegetation is autocorrelated. Field-based monitoring of vegetation and soil properties was carried out over a shrub-encroachment gradient at the Sevilleta National Wildlife Refuge in New Mexico, USA. Results of this study show that vegetation cover decreases over the shrub-encroachment gradient, but vegetation-patch size increases, with a concurrent increase in the spatial heterogeneity of soil properties. Typically, there are significant differences in soil properties between non-vegetated and vegetated surfaces, but for grass and shrub patches, there are only significant differences for the biotic soil properties. Results suggest that it is the development of larger, well-connected, non-vegetated patches that is most important in driving the overall behavior of shrub-dominated sites. Results of this study support the hypothesis that feedbacks of functional connectivity reinforce the development of structural connectivity, which increases the resilience of the shrub-dominated state, and thus makes it harder for grasses to re-establish and reverse the vegetation change. |
英文关键词 | ecohydrology spatial autocorrelation grassland shrubland structure function land degradation |
类型 | Article |
语种 | 英语 |
国家 | USA ; England |
收录类别 | SCI-E |
WOS记录号 | WOS:000284156700008 |
WOS关键词 | NORTHERN CHIHUAHUAN DESERT ; SEMIARID LAND DEGRADATION ; SOUTHERN NEW-MEXICO ; LANDSCAPE CONNECTIVITY ; TERRESTRIAL ECOSYSTEMS ; CONCEPTUAL-FRAMEWORK ; SPATIAL VARIABILITY ; NATURAL-ABUNDANCE ; OVERLAND-FLOW ; NITROGEN |
WOS类目 | Ecology |
WOS研究方向 | Environmental Sciences & Ecology |
来源机构 | Arizona State University |
资源类型 | 期刊论文 |
条目标识符 | http://119.78.100.177/qdio/handle/2XILL650/163948 |
作者单位 | 1.Arizona State Univ, Global Inst Sustainabil, Tempe, AZ 85287 USA; 2.Univ Sheffield, Dept Geog, Sheffield Ctr Int Drylands Res, Sheffield S10 2TN, S Yorkshire, England; 3.Univ Exeter, Dept Geog, Exeter EX4 4RJ, Devon, England; 4.Rothamsted Res, Sustainable Soils & Grassland Syst Dept, Biogeochem Soils & Water Grp, Okehampton EX20 2SB, England |
推荐引用方式 GB/T 7714 | Turnbull, Laura,Wainwright, John,Brazier, Richard E.,et al. Biotic and Abiotic Changes in Ecosystem Structure over a Shrub-Encroachment Gradient in the Southwestern USA[J]. Arizona State University,2010,13(8):1239-1255. |
APA | Turnbull, Laura,Wainwright, John,Brazier, Richard E.,&Bol, Roland.(2010).Biotic and Abiotic Changes in Ecosystem Structure over a Shrub-Encroachment Gradient in the Southwestern USA.ECOSYSTEMS,13(8),1239-1255. |
MLA | Turnbull, Laura,et al."Biotic and Abiotic Changes in Ecosystem Structure over a Shrub-Encroachment Gradient in the Southwestern USA".ECOSYSTEMS 13.8(2010):1239-1255. |
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