دورية أكاديمية

Recent increase in autumn temperature has stabilized tree growth in forests near the tree lines in Chilean Patagonia.

التفاصيل البيبلوغرافية
العنوان: Recent increase in autumn temperature has stabilized tree growth in forests near the tree lines in Chilean Patagonia.
المؤلفون: Gibson‐Carpintero, Stephanie, Venegas‐González, Alejandro, Urra, Vinci D., Estay, Sergio A., Gutiérrez, Álvaro G.
المصدر: Ecosphere; Oct2022, Vol. 13 Issue 10, p1-14, 14p
مصطلحات موضوعية: TIMBERLINE, DROUGHTS, AUTUMN, TREE-rings, TREE growth, FOREST dynamics, SNOW cover, TEMPERATE forests
مصطلحات جغرافية: PATAGONIA (Argentina & Chile), ANDES, CHILE
مستخلص: It is widely accepted that global warming is affecting forests near the tree line by increasing tree growth in these cold‐limited environments. However, since about 1970, a reduction in tree growth near the tree line has been observed in response to warming and increased drought stress. This reduction in tree growth has been mainly reported in forests of the northern hemisphere but less studied in southern forests. In this study, we investigated tree populations of Nothofagus pumilio located near the arboreal altitudinal limit in the central Patagonian Andes (45–47° S, Aysén region, Chile). In this region, warming has been accompanied by increased drought conditions since the 2000s. We explored whether this climatic variability has promoted or reduced tree growth at the regional scale in tree lines of these broadleaved temperate forests of central Patagonia. We constructed tree‐ring chronologies and determined common growth patterns and trends, and then analyzed the influence of recent climate. We detected a significant change in the slope of regional growth trends between the periods 1955–1985 and 1985–2015. We found that positive growth trends in the period 1955–1985 were associated with warmer and drier springs. However, after 1985, we found a stabilization in N. pumilio growth associated with a steady increase in temperature in autumn. Our results support the idea that more frequent warm autumns, with very thin or no snow cover, have stabilized tree growth due to water deficit at the end of the growing season of N. pumilio. The predicted climate change scenario of increasing temperatures and drought in central Patagonia may increase competition among trees for water, particularly at the end of the growing season. Consequently, we could expect a decreasing forest growth trend in central Patagonia, potentially impacting forest dynamics of these southern forests. [ABSTRACT FROM AUTHOR]
Copyright of Ecosphere is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
قاعدة البيانات: Complementary Index