Ramírez Jorge Andrés, Ignacio del Valle Jorge
Département des Sciences Biologiques, Université du Québec a Montréal, Centre d'etude de la Forêt.
Rev Biol Trop. 2011 Sep;59(3):1389-405.
There is great concern about the effect of climate change in arid and subarid areas of the tropics. Climate change combined with other anthropogenic activities such as deforestation, fires and over-grazing can accelerate their degradation and, consequently, the increases in losses of biological and economic productivity. Climate models, both local and global, predict that rainfall in the arid Peninsula of La Guajira in the Colombian Caribbean would be reduced and temperature would be increased as a result of climate change. However, as there are only suitable climate records since 1972, it is not possible to verify if, indeed, this is happening. To try to verify the hypothesis of reducing rainfall and rising temperatures we developed a growth ring chronology of Capparis odoratissima in the Middle Peninsula of La Guajira with 17 trees and 45 series which attain 48 years back. We use standard dendrochronological methods that showed statistically significant linear relationship with local climatic variables such as air temperature, sea surface temperature (SST), annual precipitation and wind speed; we also reach to successful relationship of the chronology with global climatic variables as the indices SOI and MEI of the ENSO phenomenon. The transfer functions estimated with the time series (1955 and 2003) do not showed statistically significant trends, indicating that during this period of time the annual precipitation or temperatures have not changed. The annual nature of C. odoratissima growth rings, the possibility of cross-dated among the samples of this species, and the high correlation with local and global climatic variables indicate a high potential of this species for dendrochronological studies in this part of the American continent.
热带干旱和半干旱地区的气候变化影响备受关注。气候变化与森林砍伐、火灾和过度放牧等其他人为活动相结合,会加速这些地区的退化,进而导致生物和经济生产力损失增加。无论是局部还是全球气候模型都预测,由于气候变化,哥伦比亚加勒比地区瓜希拉半岛干旱地区的降雨量将减少,气温将升高。然而,由于自1972年以来才有合适的气候记录,因此无法核实这种情况是否真的正在发生。为了试图验证降雨量减少和气温上升的假设,我们在瓜希拉半岛中部地区以17棵树和45个序列建立了香花番荔枝的年轮年表,该年表可追溯到48年前。我们使用标准的树木年代学方法,结果表明其与当地气候变量(如气温、海表面温度(SST)、年降水量和风速)存在统计学上显著的线性关系;我们还成功地建立了该年表与全球气候变量(如ENSO现象的南方涛动指数(SOI)和多变量厄尔尼诺指数(MEI))的关系。利用时间序列(1955年和2003年)估算的传递函数未显示出统计学上显著的趋势,这表明在此期间年降水量或气温没有变化。香花番荔枝年轮的年度特征、该物种样本间交叉定年的可能性以及与当地和全球气候变量的高度相关性,表明该物种在美洲大陆这一地区进行树木年代学研究具有很高的潜力。