针叶树形成层活动及径向生长监测研究进展

Research progress on cambium activity and radial growth dynamics monitoring of coniferous species

树木径向生长是森林固碳的主要方式,明确树木生长动态及其与环境要素的响应关系对于预测气候变化背景下森林固碳能力具有重要意义。针叶树生长对气候变化非常敏感,其生长动态能够快速响应气候变化。本文收集了1975—2023年的99篇文献,评述了外源因素(温度、水分和光周期)和内在因素(树龄、树种)对针叶树形成层活动和径向生长的影响及其机制。结果表明:气候变暖可能会导致温带和北方针叶树木质部分化的各阶段开始时间提前,生长停止时间推迟;水分条件参与调控形成层活动的开始并通过影响水势和细胞膨压进而调节树木生长;光周期除了可以参与调节生长开始、结束时间外,也对最大生长速率发生时间产生重要影响。未来气候变暖可能会使北方针叶树生长季延长、生长量增加,并使森林向更高海拔或高纬度地区迁移。同时,未来降水格局改变以及温度升高导致的蒸散发加剧可能会使干旱区树木生长季提前结束,生长速率下降。在未来研究中,还需进一步开发树木生长过程模型,量化径向生长与气候要素的关系,以便进一步明确树木生长对气候要素响应的生理机制。

The radial growth of trees plays a crucial role in determining forest carbon sequestration capacity.Understanding the growth dynamics of trees and their response to environmental factors is essential for predicting forest's carbon sink potential under future climate change.Coniferous forest trees are particularly sensitive to climate change,with growth dynamics responding rapidly to environmental shifts.We collected and analyzed data from 99 papers published between 1975 and 2023,and examined the effects of exogenous factors(such as temperature,water,and photoperiod)and endogenous factors(including tree age and species)on cambial activity and radial growth in conifers.We further explored the mechanisms underlying these effects.The results showed that climate warming had the potential to advance the onset while delayed the end of xylem differentiation stages in conifers in temperate and boreal regions.Water availability played a crucial role in regulating the timing of cambial phenology and wood formation by influencing water potential and cell turgor.Additionally,the photoperiod not only participated in regulating the start and end times of growth,but also influenced the timing of maximum growth rate occurrence.Future climate warming was expected to extend the growing season,leading to increase in growth of conifers in boreal regions and expanding forests to higher altitudes or latitudes.However,changes in precipitation patterns and increased evapotranspiration resulting from temperature increases might advance the end of growing season and reduce growth rate in arid areas.To gain a more comprehensive understanding of the relationship between radial growth and climatic factors,it is necessary to develop process-based models to elucidate the physiological mechanisms underlying wood formation and the response of trees to climatic factors.