Xie Jin, Yan Qiao-Ling, Zhang Ting
Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shen-yang 110016, China.
Qingyuan Forest CERN, Chinese Academy of Sciences, Shenyang 110016, China.
Ying Yong Sheng Tai Xue Bao. 2020 Aug;31(8):2481-2490. doi: 10.13287/j.1001-9332.202008.010.
Understanding the temporal effects of thinning on the composition and growth of regene-rated broadleaved woody species in coniferous plantations can provide profound references for promoting the conversion of monoculture plantations into mixed conifer-broadleaved forests, which could solve the problem that the production and ecological functions of monoculture plantations cannot be balanced. We compared the composition of regenerated woody plant species in plantation with short-term (1-3 years), medium-term (4-9 years) and long-term (>9 years) after thinning. Furthermore, we selected three regenerated tree species with higher importance value and reciprocal symbiosis with , which differed in shade tolerance, including shade-intolerant species , intermediate shade-tolerant species , and shade-tolerant species . We analyzed the relationships between light conditions (., canopy density) and the growth (., base diameter and height) of those species in plantation with different terms after thinning. The results showed that 46 species of regene-rated broadleaved woody plants were recorded in thinned plantations. The common and dominant tree in different terms after thinning was , and the shrub species were and . With the increasing time after thinning, species richness of regenerated trees decreased, but the ratio of tree to shrub species increased and the intermediate shade-tolerant tree species took the dominant position. The temporal effect of thinning on the growth of three tree species was affected by shade tolerance ability. Basal diameter and height of were higher than those of and . With the increases of time after thinning, basal diameter of and height of were more sensitive to light, indicating that there were respectively "a shade tolerance strategy" and "a shade avoidance strategy" to adapt to the post-thinning environment. The effects of thinning on the composition and growth of regenerated broadleaved woody species in plantations were significantly time-sensitive. When deve-loping thinning measures to promote the regeneration of broadleaved trees in plantations, we should consider to extend the thinning interval appropriately to ensure the growth of broadleaved tree seedlings (., and ) and accelerate their migration into the canopy layer. This would promote the formation of mixed conifer-broadleaved forests and eventually realize the sustainable development of plantations.
了解间伐对针叶人工林中再生阔叶木质物种组成和生长的时间效应，可为推动单一栽培人工林转变为针叶 - 阔叶混交林提供深刻参考，这能够解决单一栽培人工林生产功能与生态功能无法平衡的问题。我们比较了间伐后短期（1 - 3年）、中期（4 - 9年）和长期（>9年）人工林中再生木本植物物种的组成。此外，我们选择了三种重要值较高且相互共生的再生树种，它们的耐荫性不同，包括不耐荫物种、中度耐荫物种和耐荫物种。我们分析了不同间伐期人工林中光照条件（如林冠密度）与这些物种生长（如基径和树高）之间的关系。结果表明，在间伐后的人工林中记录到46种再生阔叶木质植物。间伐后不同时期的常见优势树种为，灌木物种为和。随着间伐后时间的增加，再生树木的物种丰富度降低，但乔木与灌木物种的比例增加，中度耐荫乔木物种占据主导地位。间伐对三种树种生长的时间效应受耐荫能力影响。的基径和树高高于和。随着间伐后时间的增加，的基径和的树高对光照更敏感，表明分别存在“耐荫策略”和“避荫策略”以适应间伐后的环境。间伐对人工林中再生阔叶木质物种组成和生长的影响具有显著的时间敏感性。在制定促进人工林阔叶树再生的间伐措施时，应考虑适当延长间伐间隔，以确保阔叶树苗（如和）的生长并加速它们向林冠层迁移。这将促进针叶 - 阔叶混交林的形成并最终实现人工林的可持续发展。
