Dendroclimatic signals deduced from riparian versus upland forest interior pines in North Karelia, Finland
Dendroclimatic signals deduced from riparian versus upland forest interior pines in North Karelia, Finland
复制标题
从芬兰北卡累利阿河岸与高地森林内部松树推断出的树木气候信号
作者：
S. Helama;B. W. Arentoft;Olivier Collin;M. Hyslop;Charlotte K. Brandstrup;Hanna M. Mäkelä;Qinhua Tian;R. Wilson
在河岸生境中，北方树种的径向生长很少被研究。在这里，我们研究了生长在芬兰东部北方森林中的河岸湖岸和高地森林内部松树（Pinus sylvestris L.）的早材、晚材和年轮宽度和蓝色强度（BI；晚材密度的替代）的年表。对河岸和高地的年表进行比较，以检查两个栖息地松树生长变异性和生长对气候变化的响应的差异。研究发现，与树木年轮年表显示统计显着相关性的气候变量与生长季节开始时的降雪条件有关。更深的积雪导致高地松树生长减少，这可能是由于融雪延迟，从而推迟了生长季节的开始。温暖的冬末之后，由于融雪季节开始较早，河岸松树生长增加，因此初夏湖泊最高水位较低。此外，河岸松对六月降雨量增加产生负面反应，而高地松则表现出积极反应。晚材生长对夏季气温反应显着。 BI年代学显示与暖季温度有很强的相关性，这表明利用中/南针叶松年轮档案重建夏季温度的可能性令人鼓舞。
Radial growth of boreal tree species is only rarely studied in riparian habitats. Here we investigated chronologies of earlywood, latewood, and annual ring widths and blue intensity (BI; a surrogate to latewood density) from riparian lake shore and upland forest interior pines (Pinus sylvestris L.) growing in boreal forest in eastern Finland. Riparian and upland chronologies were compared to examine differences in the pine growth variability and growth response to climatic variation in the two habitats. It was found that the climatic variables showing statistically significant correlations with the tree-ring chronologies were related to snow conditions at the start of the growing season. Deeper snowpack led to reduced upland pine growth, possibly due to delayed snowmelt and thus postponed onset of the growing season. Warm late winters were followed by increased riparian pine growth because of earlier start of the snow-melt season and thus a lower maximum early summer lake level. Moreover, riparian pines reacted negatively to increased rainfall in June, whereas the upland pines showed a positive response. Latewood growth reacted significantly to summer temperatures. The BI chronology showed a strong correlation with warm-season temperatures, indicating an encouraging possibility of summer temperature reconstruction using middle/south boreal pine tree-ring archives.