Birch stands growth increase in Western Siberia
Birch stands growth increase in Western Siberia
复制标题
西西伯利亚的桦树生长呈增长趋势
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
K. Ranson
中科院分区：
文献类型：
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作者：
V. Kharuk;V. Kuzmichev;S. Im;K. Ranson
根据西西伯利亚森林草原长期(1897-2006年)的调查数据(树高、胸径和林分蓄积量)，分析了白桦的生长情况。对生物计量参数的分析表明，与19世纪末的类似林分(林龄=40-60年)相比，21世纪初的林分生长速度更快。平均树高从14 m增加到20 m，胸径从16 cm增加到22 cm，平均材积从∼63增加到∼220m~3/ha。林分平均树高、胸径、材积与植被周期长度(r_s=0.71~0.74)、大气CO_2浓度(r_s=0.71~0.76)、干旱指数(标准化降水-蒸散指数，r_s=−0.33~−0.51)呈显著正相关。结果表明，气候对林分生长有明显的影响(如植被周期的延长和干旱导致的桦树生境干燥)。此外，桦树生物特征参数与环境空气中[CO2]的高度相关性表明了CO2施肥的影响。与此同时，进一步的干旱加剧可能会使白桦林的生长陷入衰退和更大的死亡率，就像已经在跨贝加尔河森林草原交错带观察到的那样。
Birch (Betula pendula Roth) growth within the Western Siberia forest-steppe was analyzed based on long-term (1897–2006) inventory data (height, diameter at breast height [dbh], and stand volume). Analysis of biometry parameters showed increased growth at the beginning of twenty-first century compared to similar stands (stands age = 40–60 years) at the end of nineteenth century. Mean height, dbh, and stem volume increased from 14 to 20 m, from 16 to 22 cm, and from ∼63 to ∼220 m3/ha, respectively. Significant correlations were found between the stands mean height, dbh, and volume on the one hand, and vegetation period length (rs = 0.71 to 0.74), atmospheric CO2 concentration (rs = 0.71 to 0.76), and drought index (Standardized Precipitation-Evapotranspiration Index, rs = −0.33 to −0.51) on the other hand. The results obtained have revealed apparent climate-induced impacts (e.g. increase of vegetation period length and birch habitat drying due to drought increase) on the stands growth. Along with this, a high correlation of birch biometric parameters and [CO2] in ambient air indicated an effect of CO2 fertilization. Meanwhile, further drought increase may switch birch stand growth into decline and greater mortality as has already been observed within the Trans-Baikal forest-steppe ecotone.