Dendroclimatological studies in a dry inner Alpine environment (750 m a.s.l.) revealed different growth response of co-occurring coniferous species to climate, which is assumed to be caused by a temporal shift in wood formation among species. The main focus of this study therefore was to monitor intra-annual dynamics of radial increment growth of mature deciduous and evergreen coniferous species (Pinus sylvestris, Larix decidua and Picea abies) during two consecutive years with contrasting climatic conditions. Radial stem growth was continuously followed by band dendrometers and modelled using Gompertz functions to determine time of maximum growth. Histological analyses of tree ring formation allowed determination of temporal dynamics of cambial activity and xylem cell development. Daily fluctuations in stem radius and radial stem increments were extracted from dendrometer traces, and correlations with environmental variables were performed. While a shift in temporal dynamics of radial growth onset and cessation was detected among co-occurring species, intra-annual radial growth peaked synchronously in late May 2011 and early June 2012. Moist atmospheric conditions, i.e. high relative air humidity, low vapour pressure deficit and low air temperature during the main growing period, favoured radial stem increment of all species. Soil water content and soil temperature were not significantly related to radial growth. Although a temporal shift in onset and cessation of wood formation was detected among species, synchronous culmination of radial growth indicates homogenous exogenous and/or endogenous control. The close coupling of radial growth to atmospheric conditions points to the importance of stem water status for intra-annual growth of drought-prone conifers.

中文翻译：

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内高山地区易干旱混合针叶林中小气候和土壤水分的径向茎生长

在干燥的高山内部环境（750 m asl）中进行的树木气候学研究揭示了同时发生的针叶树物种对气候的不同生长反应，这被认为是由物种间木材形成的时间变化引起的。因此，本研究的主要重点是监测成熟落叶和常绿针叶树（樟子松、落叶松和云杉）在气候条件不同的连续两年内径向增量生长的年内动态。径向茎生长由带状树状仪连续跟踪，并使用 Gompertz 函数建模以确定最大生长时间。树轮形成的组织学分析允许确定形成层活动和木质部细胞发育的时间动态。从测树仪轨迹中提取了茎半径和径向茎增量的每日波动，并与环境变量进行了相关性分析。虽然在同时出现的物种中检测到径向生长开始和停止的时间动态变化，但年内径向生长在 2011 年 5 月下旬和 2012 年 6 月上旬同步达到峰值。潮湿的大气条件，即高相对空气湿度，低蒸汽压赤字主要生长期气温偏低，有利于各品种径向茎增。土壤含水量和土壤温度与径向生长无显着相关。尽管在物种之间检测到木材形成的开始和停止的时间变化，但径向生长的同步高潮表明同质的外源和/或内源控制。