Prolonged Soil Frost Affects Hydraulics and Phenology of Apple Trees.
Prolonged Soil Frost Affects Hydraulics and Phenology of Apple Trees.
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DOI：
10.3389/fpls.2016.00867
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发表时间：
2016
影响因子：
5.6
通讯作者：
Mayr S
中科院分区：
文献类型：
--
作者：
Beikircher B;Mittmann C;Mayr S
在温带地区，春季恢复充足的水分供应是被子植物生存的先决条件。树木必须重新获得土壤水分，恢复木质部功能。因此，我们假设，长期的土壤霜冻损害恢复和影响苹果的水力学和物候。金冠。为了验证这一假设，在连续两个冬天的一些树木周围的土壤被绝缘，以延长土壤霜冻，从仲冬到初夏，本地栓塞的水平，木材，树皮和芽的水和淀粉含量进行了定量，定期和调查结果与各种物候参数，木质化和细根生长。研究结果证实，长期土壤霜冻影响树木的水力学和物候，但影响的严重程度取决于气候条件。在这两个研究年，百分比损失的水力传导率（PLC）从约70%，在冬季结束时，在5月下降到约10%。因此，木质部再填充强烈一致的木材和树皮淀粉的减少。同样经过处理的树木能够在5月前恢复其液压系统，但在2012年温暖的春天，木质部重新填充，含水量增加和淀粉解聚被推迟。相比之下，在2013年寒冷的春天，仅观察到对照和处理树之间的微小差异。延长土壤霜冻也导致延迟物候，木质部，细根生长。我们的结论是，减少从冻结或寒冷的土壤水分吸收损害回填，从而对树水力学和苹果树在春季的生长产生负面影响。在不利的情况下，这可能会导致严重的冬季损害，甚至枯死。
Restoration of an adequate water supply in spring is a prerequisite for survival of angiosperm trees in temperate regions. Trees must re-establish access to soil water and recover xylem functionality. We thus hypothesized that prolonged soil frost impairs recovery and affects hydraulics and phenology of Malus domestica var. ‘Golden Delicious.’ To test this hypothesis, over two consecutive winters the soil around some trees was insulated to prolong soil frosting, From mid-winter to early summer, the level of native embolism, the water and starch contents of wood, bark and buds were quantified at regular intervals and findings correlated with various phenological parameters, xylogenesis and fine root growth. The findings confirm that prolonged soil frost affects tree hydraulics and phenology but the severity of the effect depends on the climatic conditions. In both study years, percentage loss of hydraulic conductivity (PLC) decreased from about 70% at the end of winter to about 10% in May. Thereby, xylem refilling strongly coincided with a decrease of starch in wood and bark. Also treated trees were able to restore their hydraulic system by May but, in the warm spring of 2012, xylem refilling, the increases in water content and starch depolymerization were delayed. In contrast, in the cold spring of 2013 only small differences between control and treated trees were observed. Prolongation of soil frost also led to a delay in phenology, xylogenesis, and fine root growth. We conclude that reduced water uptake from frozen or cold soils impairs refilling and thus negatively impacts tree hydraulics and growth of apple trees in spring. Under unfavorable circumstances, this may cause severe winter damage or even dieback.