The effects of artificial soil frost on cambial activity and xylem formation in Norway spruce
The effects of artificial soil frost on cambial activity and xylem formation in Norway spruce
复制标题
人工土壤霜对挪威云杉形成层活性和木质部形成的影响
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
T. Repo
中科院分区：
文献类型：
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作者：
T. Jyske;M. Manner;H. Mäkinen;P. Nöjd;Heli Peltola;T. Repo
以47年生挪威云杉（Piceabies（L.）喀斯特。生长在芬兰东部（62°42′N; 29°45′E）中等肥沃的土地类型（有冰碛土）上的乔木。不同的土壤霜冻处理是：（1）自然积雪和融化（控制，CTRL）;（2）人工清除雪从土壤表面连续两个冬天（开放）;（3）积雪清除和绝缘（FROST），这是在其他方面类似于开放，但地面绝缘早春，以延迟土壤解冻。每个处理重复3块，在每个小区的两个样品树在2006-2007年的生长季节重复微芯的木质部形成的开始，停止和持续时间的分析。管胞分化的阶段（管胞径向扩大，次生细胞壁的形成，和成熟的管胞）从2007年的微芯进行了测量。年轮内生长和木材密度变量进行了分析的基础上X射线密度测定。在2006年的霜冻中，木质部的形成比其他处理晚一周。在2007年，没有发现治疗之间的差异。两个研究年度之间的结果差异可能是由于年度之间的天气变化，即，2005/2006年的冬季比2006/2007年寒冷。土壤霜冻处理对管胞分化和大多数环内生长和密度变量没有影响。我们的研究结果表明，冰碛土的延迟解冻可能会轻微影响挪威云杉木质部形成的开始，时间和持续时间。然而，延迟土壤霜冻的影响也可能取决于土壤类型，并随着土壤持水量的增加而变得更加明显。
We studied the effects of artificial soil frost on cambial activity and xylem formation on 47-year-old Norway spruce [Picea abies (L.) Karst.] trees grown on medium fertile site type (with moraine soil) in eastern Finland (62°42′N; 29°45′E). Different soil frost treatments applied were: (1) natural snow accumulation and melting (control, CTRL); (2) artificial removal of snow from soil surface during two consecutive winters (OPEN); and (3) snow clearing and insulation (FROST), which was in other ways similar to OPEN, but the ground was insulated in early spring to delay soil thawing. Each treatment was replicated in three blocks, and two sample trees in each plot were repeatedly microcored during growing seasons of 2006–2007 for the analysis of the onset, cessation and the duration of xylem formation. The phases of tracheid differentiation (tracheids in radial enlargement, secondary cell wall formation, and mature tracheids) were measured from the microcores of 2007. The intra-ring growth and wood density variables were analysed based on X-ray densitometry. In FROST in 2006, xylem formation started a week later than in the other treatments. In 2007, no difference was found between the treatments. The discrepancy in results between the two study years may be explained by between-years variation in weather, i.e., the winter was colder in 2005/2006 than in 2006/2007. No effects of soil frost treatments on tracheid differentiation and on most of the intra-ring growth and density variables were discovered. Our results suggest that the delayed thawing of moraine soil may slightly affect the onset, timing and duration of xylem formation in Norway spruce. However, the effects of delayed soil frost may depend also on the soil type and become more evident with increasing water holding capacity of the soil.