Журнал Сибирского федерального университета: Серия Биология (Dec 2015)
Fixing of Warming of Climate in Ring Chronologies of Shrubs in the North of Yamal and Gyda Peninsula
Abstract
The tree ring chronology (TRC) of a gray willow (Salix glauca) growing on a northern limit of the distribution on the Yamal Peninsula (the lake Langatibeyto, 71°04’35” N, 70°22’09” E) and Gyda Peninsula (lake Goltsovoye, 71°24’84” N, 78°50’58” E) was constructed. The maximum datings of shrubs correspond to 1965 and 1954. It was also constructed the integrated century (1874-2011) TRC of the shrubs of Northern Yamal – a gray willow, shaggy willow (Salix lanata), a dwarfish birch (Betula nana), which includes TRC of both Langatibeyto’s point and the territory of the Bovanenkovskoe gas-condensate field (70°21’45” N, 68°26’49” E). Owing to biological features of growth of tundra shrubs the chronologies of absolute width of their rings show good compliance with the general trend of climate warming of the region in XX – the beginning of the XXI centuries. The compliance isn’t traced if indexation is used, for example, by the method of negative exponential smoothing because it demands the larger extent of chronologies. The greatest response of an absolute radial gain of shrubs is noted on the air temperature of summer months of the current year, first of all July (on Gyda), and also June (on Yamal). Correlation of TRC with summer air temperatures of the nearby meteorological stations (Antipayuta on Gyda Peninsula, Kharasavey on Yamal) reaches +0,72. Correlation of TRC of Northern Yamal with summer temperatures of Salekhard makes 0,65-0,68 that allows to use widely its long set of meteodata (since 1882) on Yamal, and to use a meteodata of Dickson (since 1916) on Gyda. A response of the studied TRC to the spring air temperatures making the greatest contribution to the warming of climate of the region is low and in general negative (correlation coefficient is about –0,3), a response to the previous winter temperatures is low and in general positive (about 0,3). On Yamal in comparison with Gyda the curve of responses to monthly air temperatures is displaced for earlier calendar terms. Determination of parameters of multiple regression of TRC of Northern Yamal on average monthly air temperatures of Salekhard and Marre-Sale using models with different number of the months-predictors showed high (0,7-0,9) and significant by all criteria correlation, both for training, and for control part of chronology. It is indicative that the high correlation is found in models of regression of TRC on three months of the summer season (0,74-0,78) which is on the second place on a contribution to warming of climate of the region after the spring period. The similar picture is shown by TRC of an shrubby alder (Duschekia fruticosa) and a shaggy willow from a northern limit of a zone of the shrubby tundra of Yamal (68°29’41 “N, 72°27’10” E) where the century trend of increase in width of rings is more, but multiple correlation with temperatures of summer months is slightly weaker (0,63–0,68)
