Controls on Radial Growth of Mountain Big Sagebrush and Implications for Climate Change
Controls on Radial Growth of Mountain Big Sagebrush and Implications for Climate Change
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山艾树径向生长的控制及其对气候变化的影响
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
B. Enquist
中科院分区：
文献类型：
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作者：
R. Poore;C. Lamanna;J. J. Ebersole;B. Enquist
抽象的。山艾树（Artemisia tridentata Nutt. ssp. vaseyana）覆盖北美西部干旱地区的大片地区。气候变化模型预测山艾树的范围会减少，但很少有研究探讨山艾树生长的预测变化的细节以及这些变化对群落的潜在影响。我们分析了 1969 年至 2007 年科罗拉多州甘尼森盆地温度、降水和积雪深度对山艾树年轮宽度的影响。除冬季外，一年中所有时间的温度均与年轮宽度呈负相关；夏季气温负相关最强。除夏季外，各季节环宽与降水量呈正相关；冬季降水与生长的关系最强。最大积雪深度也与环宽度呈正相关且强烈相关。多元回归表明，夏季温度和冬季降水或最大雪深（可为更深的土壤层补给）对于控制生长都很重要。总体而言，水分胁迫，尤其是最大雪深似乎限制了该物种的生长。随着预计气温上升和积雪深度可能减少，山艾树的生长速度可能会下降。如果是这样，山艾树的数量和覆盖率可能会下降，这可能会对群落组成和碳平衡产生重大影响。
ABSTRACT. Mountain big sagebrush (Artemisia tridentata Nutt. ssp. vaseyana) covers large areas in arid regions of western North America. Climate-change models predict a decrease in the range of sagebrush, but few studies have examined details of predicted changes on sagebrush growth and the potential impacts of these changes on the community. We analyzed effects of temperature, precipitation, and snow depth on sagebrush annual ring width for 1969 to 2007 in the Gunnison Basin of Colorado. Temperature at all times of year except winter had negative correlations with ring widths; summer temperature had the strongest negative relationship. Ring widths correlated positively with precipitation in various seasons except summer; winter precipitation had the strongest relationship with growth. Maximum snow depth also correlated positively and strongly with ring width. Multiple regressions showed that summer temperature and either winter precipitation or maximum snow depth, which recharges deeper soil horizons, are both important in controlling growth. Overall, water stress and perhaps especially maximum snow depth appear to limit growth of this species. With predicted increases in temperature and probable reduced snow depth, sagebrush growth rates are likely to decrease. If so, sagebrush populations and cover may decline, which may have substantial effects on community composition and carbon balance.