Carbon isotope discrimination of C3 vegetation in Central Asian grassland as related to long-term and short-term precipitation patterns
Carbon isotope discrimination of C3 vegetation in Central Asian grassland as related to long-term and short-term precipitation patterns
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DOI：
10.5194/bg-5-913-2008
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发表时间：
2008-01-01
期刊：
影响因子：
4.9
通讯作者：
Schnyder, H.
中科院分区：
文献类型：
--
作者：
Wittmer, M. H. O. M.;Auerswald, K.;Schnyder, H.
研究了C3植被碳同位素判别（(13)δ）与长期（30年）和短期（生长期）降水的关系。2005年在内蒙古（11个样地，71个样地）和2006年在蒙古共和国（40个样地，45个样地）沿干旱梯度采集了亚洲（半）干旱草原的优势草属针茅和其他C3种。利用已发表和未发表的针虫和其他C3物种的数据（11项研究，8年，其中针虫64次，其他C3物种103次）和C3群落大样本（11个样本）对数据集进行扩展。对所有采样地点和年份的天气数据进行地质统计学插值。（13）由于年平均降水模式与长期平均降水模式之间存在较大的距平，针茅的三角洲与年平均降水的关系在各年之间存在差异。然而，当（长期）平均年降水量被生长期特定年平均日降水量取代时，(13)δ对降雨的响应收敛(（P) /柱(G)）。值得注意的是，C3物种（包括草本菊科植物、半灌木和禾草）对(P) / (G)的(13)δ响应以及C3群落水平的响应几乎与针茅相同。这种关系在其发展的地理和气候范围之外也是有效的，证明了它的稳健性。
The relationship between carbon isotope discrimination ((13)Delta) of C3 vegetation and long-term (30 years) and short-term ( growing period) precipitation was investigated. Different species of Stipa, a dominant grass genus in the (semi-) arid Asian steppes, and other C3 species were collected along aridity gradients in Inner Mongolia in 2005 ( 11 sites, 71 samples) and in the Republic of Mongolia in 2006 ( 40 sites, 45 samples). The data set was expanded with published and unpublished data of Stipa and other C3 species ( 11 studies covering 8 years, including 64 observations of Stipa, and 103 observations of other C3 species) and C3 community bulk-samples ( 11 samples). Weather data were geostatistically interpolated for all sampling sites and years. (13)Delta of Stipa followed different relationships for the individual years when related to mean annual precipitation due to large anomalies between annual and long-term average precipitation patterns. However, the (13)Delta response to rainfall converged when the (long-term) mean annual precipitation was replaced by year-specific mean daily precipitation during the growing period ((P) over bar (G)). Remarkably, the (13)Delta-response to ((P) over bar (G)) for C3 species as a whole (including herbaceous dicots, semi- shrubs and grasses) and also the C3 community-level response were virtually identical to that of Stipa. The relation was also valid outside the geographical and climatic range where it was developed, giving proof of its robustness.