环境因子与新疆野苹果幼苗生长和存活的相关性分析

Correlation analysis of environmental factors with the growth and survival of Malus sieversii seedlings

关键词:  野果林, 新疆野苹果, 幼苗, 微气候, 土壤酸碱度

Key words:  wild fruit forest, Malus sieversii, seedling, microclimate, soil pH

摘要:

幼苗期是资源植物整个生活史中最脆弱的时期,也是对外界环境变化最敏感的时期。然而,以往的研究在探讨植物幼苗的生长和存活时,主要依赖于气象站提供的宏观气候数据,未能充分考虑林下微气候的动态变化对幼苗生长的潜在影响。该研究以国家二级重点保护野生植物新疆野苹果(Malus sieversii)为研究对象,通过连续3年和监测其幼苗和微气候,并结合林下土壤酸碱度、草本盖度和林冠郁闭度等环境因子的调查,探究生物和非生物环境因子对新疆野苹果幼苗生长和存活的影响。结果表明:(1)生长季平均温度和土壤湿度的增加,有助于提高幼苗存活率并促进生长,并且生长季平均温度与新疆野苹果幼苗的叶片数呈显著的正效应。(2)土壤酸碱度是影响新疆野苹果幼苗的死亡率与存活率最重要的环境因子,其贡献率均是47.6%。(3)林冠郁闭度作为影响幼苗株高、基径和叶片数的关键因子,其贡献率分别达到了32.5%、61.0%和52.4%,并且幼苗性状随着郁闭度的增加而呈现出下降的趋势。(4)生长季平均温度是影响幼苗盖度的最重要环境因子,其贡献率是39.5%。综上认为,新疆野苹果幼苗的生长和存活主要受林冠郁闭度及其林下温度和土壤酸碱度的影响,在后期的保护与管理中应重点关注这些环境因子。该研究为新疆野苹果资源的科学保护与管理提供了理论依据。

Abstract:

The seedling stage is the most vulnerable and environmentally sensitive period in the life history of plant resources. However, previous studies on the growth and survival of plant seedlings mainly relied on the macroclimate data provided by meteorological stations, but failed to fully consider the potential impact of dynamic changes in the understory microclimate on seedling growth. In this study, Malus sieversii, the category Ⅱ key protected wild plants in China, was used as the research object. The effects of biotic and abiotic environmental factors on the growth and survival of seedlings for M. sieversii were investigated by monitoring their seedlings and microclimate for three consecutive years, combined with the investigation of environmental factors such as soil pH, herbaceous coverage and canopy cover. The findings provide a theoretical foundation for the scientific conservation and management of this wild plant resource. The results were as follows:(1)The increase of mean temperature and mean soil moisture of growing season was helpful to improve the survival rate and promote the growth of seedlings, and the mean temperature of growing season had a significant positive effect on the number of leaves of seedlings for M. sieversii.(2)Soil pH was the most important environmental factor for the death rate and survival rate of seedlings for M. sieversii, and the contribution rate was 47.6%.(3)Canopy cover was the key factor affecting the height, basal diameter and leaf number of seedlings, and the contribution rates were 32.5%, 61.0% and 52.4%, respectively. Furthermore, the seedling traits had a downward trend with the increase of canopy cover.(4)The mean temperature of growing season was the most important environmental factor affecting seedling coverage, and its contribution rate was 39.5%. In all, canopy cover, understory temperature and soil pH mainly affect the growth and survival of M. sieversii seedlings, which should be focused on in the later protection and management. This study provides a theoretical basis for the scientific protection and management of M. sieversii in Xinjiang.