| DOI: | 10.2172/1158402
|
| 报告号: | DOE-UO--ER64719-1
|
| 报告题名: | Final Report for DOE Project: Climate Effects on Plant Range Distributions and Community Structure of Pacific Northwest Prairies |
| 作者: | Bridgham, Scott D. [Univ. of Oregon, Eugene, OR (United States)]; Johnson, Bart [Univ. of Oregon, Eugene, OR (United States)]
|
| 出版年: | 2013
|
| 发表日期: | 2013-09-26
|
| 总页数: | 16
|
| 国家: | 美国
|
| 语种: | 英语
|
| 英文关键词: | climate change
; biodiversity
; prairies
; Pacific Northwest
; climate gradient
; range distribution
; nutrient availability
; soil respiration
; carbon cycling
; mycorrhizae
|
| 中文主题词: | 土壤
; 碳
; 土壤呼吸
; 干旱
; 降水
; 土壤含水量
|
| 主题词: | SOILS
; CARBON
; SOIL RESPIRATION
; DROUGHT
; PRECIPITATION
; SOIL MOISTURE
|
| 英文摘要: | Pacific Northwest (PNW) prairies are an imperiled ecosystem that contain a large number of plant species with high fidelity to this habitat. The few remaining high-quality PNW prairies harbor a number of sensitive, rare, and endangered plant species that may be further at-risk with climate change. Thus, PNW prairies are an excellent model system to examine how climate change will affect the distribution of native plant species in grassland sites. Our experimental objectives were to determine: (i) how climate change will affect the range distribution of native plant species; (ii) what life history stages are most sensitive to climate change in a group of key indicator native species; (iii) the robustness of current restoration techniques and suites of species to changing climate, and in particular, the relative competitiveness of native species versus exotic invasive species; and (iv) the effects of climate change on carbon and nutrient cycling and soil-microbial-plant feedbacks. We addressed these objectives by experimentally increasing temperature 2.5 to 3.0 ÂşC above ambient with overhead infrared lamps and increasing wet-season precipitation by 20% above ambient in three upland prairie sites in central-western Washington, central-western Oregon, and southwestern Oregon from fall 2010 through 2012. Additional precipitation was applied within 2 weeks of when it fell so precipitation intensity was increased, particularly during the winter rainy season but with minimal additions during the summer dry season. These three sites also represent a 520-km natural climate gradient of increasing degree of severity of Mediterranean climate from north to south. After removing the extant vegetation, we planted a diverse suite of 12 native species that have their northern range limit someplace within the PNW in each experimental plot. An additional 20 more wide-spread native species were also planted into each plot. We found that recruitment of plant species within their ranges was negatively impacted by increased temperatures, but for species planted north of their current range, increased temperature was neutral. However, for surviving plants climate treatments and site-specific factors (e.g., nutrient availability) were the strongest predictors of plant growth and seed set. When recruitment and plant growth are considered together, increased temperatures are negative within a species current range but beyond this range they become positive. Germination was the most critical stage for plant response across all sites and climate treatments. Our results underscore the importance of including plant vital rates into models that are examining climate change effects on plant ranges. Warming altered plant community composition, decreased diversity, and increased total cover, with warmed northern communities over time becoming more like ambient communities further south. In particular, warming increased the cover of annual introduced species, suggesting that the observed biogeographic pattern of increasing invasion by this plant functional group in US West Coast prairies as one moves further south is at least in part due to climate. Our results suggest that with the projected increase in drought severity with climate change, Pacific Northwest prairies may face an increase of invasion by annuals, similar to what has been observed in California, resulting in novel species assemblages and shifts in functional composition, which in turn may alter ecosystem function. Warming generally increased nutrient availability and plant productivity across all sites. The seasonality of soil respiration responses to heating were strongly dependent on the Mediterranean climate gradient in the PNW, with heating responses being generally positive during periods of adequate soil moisture and becoming neutral to negative during periods of low soil moisture. The asynchrony between temperature and precipitation may make soils less sensitive to warming. Precipitation effects were minimal for all measured responses indicating the importance of increased temperatures in driving biotic responses to climate change in Mediterranean ecosystems. However, substantially increased precipitation during the dry season would almost certainly have profound effects, but the opposite is predicted by current climate change models for the PNW. A manipulative climate change experiment embedded within a natural climate gradient provides unique insights into the degree to which biotic responses to climate change are regionally consistent and site-dependent. Perhaps surprisingly, most climatic effects that we observed were either consistent in the three sites or could be readily interpreted in terms of the gradient of increasing intensity of the Mediterranean climate from north to south. |
| URL: | http://www.osti.gov/scitech/servlets/purl/1158402
|
| Citation statistics: |
|
| 资源类型: | 研究报告
|
| 标识符: | http://119.78.100.158/handle/2HF3EXSE/40984
|
| Appears in Collections: | 过去全球变化的重建
影响、适应和脆弱性
科学计划与规划
气候变化与战略
全球变化的国际研究计划
气候减缓与适应
气候变化事实与影响
|
| File Name/ File Size |
Content Type |
Version |
Access |
License |
|
|---|
| 1158402.pdf（2263KB） | 研究报告 | -- | 开放获取 | | View
Download
|
|
| Recommended Citation: | |
Bridgham, Scott D. [Univ. of Oregon, Eugene, OR ,Johnson, Bart [Univ. of Oregon, Eugene, OR . Final Report for DOE Project: Climate Effects on Plant Range Distributions and Community Structure of Pacific Northwest Prairies. 2013-01-01.
|
|
| Service | | | Recommend this item | | | Sava as my favorate item | | | Show this item's statistics | | | Export Endnote File | | Google Scholar | | | Similar articles in Google Scholar | | | [Bridgham, Scott D. [Univ. of Oregon, Eugene, OR (United States)]]'s Articles | | | [Johnson, Bart [Univ. of Oregon, Eugene, OR (United States)]]'s Articles | | 百度学术 | | | Similar articles in Baidu Scholar | | | [Bridgham, Scott D. [Univ. of Oregon, Eugene, OR (United States)]]'s Articles | | | [Johnson, Bart [Univ. of Oregon, Eugene, OR (United States)]]'s Articles | | CSDL cross search | | | Similar articles in CSDL Cross Search | | | [Bridgham, Scott D. [Univ. of Oregon, Eugene, OR (United States)]]‘s Articles | | | [Johnson, Bart [Univ. of Oregon, Eugene, OR (United States)]]‘s Articles | | Related Copyright Policies | | Null | | 收藏/分享 | | |
|