Spatial patterns of desert annuals in relation to shrub effects on soil moisture
文献类型：期刊论文
| 作者 | Li ; J. ; Zhao ; C. Y. ; Song ; Y. J. ; Sheng ; Y. ; Zhu ; H. |
| 刊名 | JOURNAL OF VEGETATION SCIENCE
 |
| 出版日期 | 2010 |
| 卷号 | 21期号:2页码:221-232 |
| 关键词 | POSITIVE INTERACTIONS CHIHUAHUAN DESERT ARID ECOSYSTEMS PLANT-COMMUNITIES MOJAVE DESERT FACILITATION UNDERSTOREY GRASSLANDS DYNAMICS QUANTIFICATION |
| ISSN号 | 1100-9233 |
| 通讯作者 | Li, J, CAS, Key Lab Oasis Ecol & Desert Environm, Xinjiang Inst Ecol & Geog, Urumqi 830011, Peoples R China |
| 中文摘要 | Questions What are the effects of a shrub (Haloxylon ammodendron) on spatial patterns of soil moisture in different seasons? How does productivity of understorey annuals respond to these effects? Are such effects always positive for annuals under shrubs? Location South Gurbantunggut Desert, northwest China. Methods Using geostatistics, we explored seasonal patterns of topsoil moisture in a 12 x 9-m plot over the growing season. To determine spatial patterns of understorey annuals in response to H. ammodendron presence, biomass of annuals was recorded in four 0.2 x 5.0-m transects from the centre of a shrub to the space between shrubs (interspace). We also investigated vertical distribution of root biomass for annuals and soil moisture dynamics across soil profiles in shrub-canopied areas and interspaces. Results Topsoil moisture changed from autocorrelation in the wet spring to random structure in the dry season, while soil moisture below 20 cm was higher in shrub-canopied areas. Across all microhabitats, soil moisture in upper soil layers was higher than in deeper soil layers during the spring wet season, but lower during summer drought. Topsoil was close to air-dry during the dry season and developed a 'dry sand layer' that reduced evaporative loss of soil water from deeper layers recharged by snowmelt in spring. Aboveground biomass of understorey annuals was lowest adjacent to shrub stems and peaked at the shrub margin, forming a 'ring' of high herbaceous productivity surrounding individual shrubs. To acclimate to drier conditions, annuals in interspaces invested more root biomass in deeper soil with a root/shoot ratio (R/S) twice that in canopied areas. Conclusions Positive and negative effects of shrubs on understorey plants in arid ecosystems are commonly related to nature of the environmental stress and tested species. Our results suggest there is also microhabitat-dependence in the Gurbantunggut Desert. Soil water under H. ammodendron is seasonally enriched in topsoil and deeper layers. Understorey annuals respond to the effect of shrubs on soil water availability with lower R/S and less root biomass in deeper soil layers and develop a 'ring' of high productivity at the shrub patch margin where positive and negative effects of shrubs are balanced. |
| 学科主题 | 植物生态学 |
| 收录类别 | SCI |
| 公开日期 | 2011-08-19 |
| 源URL | [http://ir.xjlas.org/handle/365004/9990]  |
| 专题 | 新疆生态与地理研究所_中国科学院新疆生态与地理研究所(2010年以前数据) |
| 推荐引用方式 GB/T 7714 | Li,J.,Zhao,et al. Spatial patterns of desert annuals in relation to shrub effects on soil moisture[J]. JOURNAL OF VEGETATION SCIENCE,2010,21(2):221-232. |
| APA | Li.,J..,Zhao.,C. Y..,Song.,...&H..(2010).Spatial patterns of desert annuals in relation to shrub effects on soil moisture.JOURNAL OF VEGETATION SCIENCE,21(2),221-232. |
| MLA | Li,et al."Spatial patterns of desert annuals in relation to shrub effects on soil moisture".JOURNAL OF VEGETATION SCIENCE 21.2(2010):221-232. |
入库方式： OAI收割
来源：新疆生态与地理研究所
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