Hydraulic traits and tree-ring width in Larix sibirica Ledeb. as affected by summer drought and forest fragmentation in the Mongolian forest steppe
Hydraulic traits and tree-ring width in Larix sibirica Ledeb. as affected by summer drought and forest fragmentation in the Mongolian forest steppe
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DOI：
10.1007/s13595-018-0701-2
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发表时间：
2018-03
影响因子：
3
通讯作者：
Elmira Khansaritoreh;B. Schuldt;C. Dulamsuren
中科院分区：
文献类型：
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作者：
Elmira Khansaritoreh;B. Schuldt;C. Dulamsuren
在北方森林南缘干旱限制的蒙古森林草原中，决定落叶松水力结构的木材解剖特征对夏季干旱有反应，但对取决于林分大小的小气候变化的反应很弱。sibiricaLedeb.）受夏季干旱的限制，蒙古森林草原的死亡率不断上升。树干材形成的气候敏感性随着林分规模的减小而增加。树木的水力结构对于抗旱性和应对气候变暖的能力是至关重要的。目的我们研究了水分供应的时间或森林大小依赖性变化是否会影响树木的水力结构，并与树木年轮宽度相关。（管胞直径，管胞密度，在30年（1985 - 2014年）的干材系列中研究了早材的潜在边材区域特定导水率），并与气候数据相关。在同一时期测量了树轮宽度。树木被选中的四个不同大小的类，增加干旱暴露与减少的立场size.ResultsTracheid直径和导水率下降，减少夏末降水的前一年，并与树轮宽度呈正相关。林分大小只有微弱的影响水力性状，尽管已知的影响stemwood increment.ConclusionDecreasing管胞直径，从而导水率是一个干旱驯化L。西伯利亚分布在蒙古森林草原。这些驯化发生作为一个响应干旱时期，但很少站点依赖于林分的大小。
Key messageWood-anatomical traits determining the hydraulic architecture ofLarix sibiricain the drought-limited Mongolian forest steppe at the southern fringe of the boreal forest respond to summer drought, but only weakly to variations in microclimate that depend on forest stand size.ContextSiberian larch (L. sibiricaLedeb.) is limited by summer drought and shows increasing mortality rates in the Mongolian forest steppe. The climate sensitivity of stemwood formation increases with decreasing forest stand size. The trees’ hydraulic architecture is crucial for drought resistance and thus the capability to deal with climate warming.AimsWe studied whether hydraulic traits were influenced by temporal or forest size-dependent variations in water availability and were related to tree-ring width.MethodsHydraulic traits (tracheid diameter, tracheid density, potential sapwood area-specific hydraulic conductivity) of earlywood were studied in stemwood series of 30 years (1985–2014) and were related to climate data. Tree-ring width was measured for the same period. Trees were selected in stands of four different size classes with increasing drought exposure with decreasing stand size.ResultsTracheid diameters and hydraulic conductivity decreased with decreasing late summer precipitation of the previous year and were positively correlated with tree-ring width. Forest stand size had only weak effects on hydraulic traits, despite known effects on stemwood increment.ConclusionDecreasing tracheid diameters and thus hydraulic conductivity are a drought acclimation ofL. sibiricain the Mongolian forest steppe. These acclimations occur as a response to drought periods but are little site-dependent with respect to stand size.