摘要
热带高海拔立地可能对气候的快速变化特别敏感。通过对树木线种群的样本分析,我进行了热带北美的首次长期(>300年)年轮年代学研究。样地位于墨西哥新火山带西端的科利马(Nevado de Colima),研究树种为墨西哥山松(Pimus hartwegii)。尽管该地区过去曾进行过采伐,但在现有树木线以下约300m,海拔3600～3700m处发现有300～500年生的老龄松树。科利马(Nevado de Coolima)年轮年代从1600年至1997年。用科利马气候记录进行校准,表明夏季季风降雨为最明显的树木气候标志。大多数树木在1913年和1914年都表现出极端低生长,而这以前1913年1月科利马火山(Volcan de Colima)曾经突然爆发。由于P.hartwegii见于由墨西哥至瓜地马拉的高山山顶,所以有可能建成热带树木线年代学网络。
High-elevation sites in the tropics may be particularly sensitive to rapid climate change. By sampling treeline populations, I have developed the first extensive (> 300 years) tree-ring chronology in tropical North America. The site is Nevado de Colima, at the western end of the Mexica Neovolcanic Belt, and the species studied is Mexican mountain pir (Pinus hartwegii). Despite past logging in the area, 300 to 500-year pines were found at 3600-3700 m elevation, about 300 m below present treeline. The Nevado de Colima tree-ring chronology is we replicated from 1600 to 1997. Calibration with Colima climatic record points to summer monsoon precipitation as the strongest dendroclimati signal. Most trees also exhibit extremely low growth in 1913 and 1914, following the January 1913 Plinian eruption of the Volcan de Colima Because P. hartwegii is found on top of high mountains from Mexico to Guatemala, there is potential for developing a network of tropical treeline chronologies.
