Page 40 - 《广西植物》2025年第8期
P. 40

1 4 0 6                                广  西  植  物                                         45 卷
                 Abstract: To identify the key temperature and precipitation factors influencing the growth of Pinus sylvestris var.
                 mongolica at different stand agesꎬ this study focused on middle ̄aged (33 a)ꎬ mature (48 a)ꎬ and overmature (64 a)
                 P. sylvestris var. mongolica stands in Zhanggutaiꎬ Liaoning Provinceꎬ and analyzed the growth patterns ( basal area
                 incrementꎬ BAI) of these stands during 2003 - 2022. In additionꎬ the Climwin model was used to determine the
                 temperature and precipitation seasonal windows with the strongest influence on growth at different stand ages. The results
                 were as follows: (1) The BAI of the three stands significantly increased from 2003 to 2022. (2) The current July-
                 August mean temperature had the strongest influence on the growth of middle ̄aged stand. When the July-August mean
                 temperature reached 23.7 ℃ꎬ the growth ̄climate relationship of middle ̄aged stand turned from positive to negativeꎻ
                 precipitation from last November to current May showed the strongest impact on both middle ̄aged and mature stands. The
                 thresholds of precipitation at which the growth ̄climate relationship of middle ̄aged and mature stands shifted from positive
                 to negative were 124 mm and 122 mmꎬ respectively. (3) Temperature had no significant impact on the growth of mature
                 standꎻ converselyꎬ the temperature in the current July and the precipitation from last August to current May were
                 significantly positively correlated with the growth of overmature stand. (4) Precipitation was proved to be more important
                 than temperature across all stand agesꎬ with its relative importance increasing as the stands aged. Thereforeꎬ in the
                 context of a warming and drying climate trendꎬ developing forest management strategies that consider water balance and
                 vary with stand age will facilitate the growth of P. sylvestris var. mongolica plantations.
                 Key words: Pinus sylvestris var. mongolicaꎬ growth ̄climate relationshipꎬ key climate factorsꎬ seasonal windowꎬ stand
                 age difference




                樟子松( Pinus sylvestris var. mongolica) 是我国      建难度ꎮ 此外ꎬ这些研究大多重点分析树木生长
            北方干旱半干旱沙地主要的防风固沙树种ꎬ在生                              与气候间的线性关系ꎬ而自然中树木生长与气候
            态恢复、固碳增汇和改善社会宜居环境方面贡献                              关系不稳定ꎬ可能为非线性关系ꎬ甚至存在生长-
            突出(朱教君和郑晓ꎬ2019)ꎮ 然而ꎬ由于管理措施                         气候关系发生转变的气候阈值ꎬ这一偏差可能影
            未能适应当地气候环境ꎬ加上气候变化等多因素                              响气候变化背景下树木生长的预测ꎬ但相关研究
            的共同作用ꎬ樟子松存在生长衰退和成片死亡等                              较少 ( Anderson ̄Teixeira et al.ꎬ 2022ꎻ Xue et al.ꎬ
            退化问题( 于丰源等ꎬ2022)ꎮ 研究樟子松生长对                         2023)ꎮ
            气候变化的响应有助于预测森林生长变化并为森                                  樟子松径向生长与气候关系存在林龄差异ꎮ
            林可持 续 经 营 提 供 科 学 依 据ꎬ 遂 成 为 研 究 热 点               例如ꎬ张晓等(2022) 发现辽宁章古台地区樟子松

            (Sun et al.ꎬ 2021)ꎮ                                径向生长对气候的敏感性随林龄增大而增强ꎬ并
                 降水和温度是决定沙地樟子松生长和分布的                           且发现影响低龄树木生长的降水季节比高龄树木
            关键气候因子(张世林等ꎬ2023)ꎬ也是建立树木生                          晚ꎻ周凤艳等(2025)发现ꎬ影响不同林龄樟子松生

            长模型最常用的气候预测变量ꎮ 在沙地环境中ꎬ                             长的极端气候因子发生在不同季节ꎻLiu 等(2023)
            降水可调节土壤和空气水分条件进而调控樟子松                              发现中龄樟子松的气候适应性明显强于幼龄ꎮ 樟
            水分可利用性ꎬ温度可以通过改变植物生理活动                              子松生长对气候因子的响应模式( 线性 vs 非线

            和调节水文循环来影响植物的生长( Wen et al.ꎬ                       性)是否随林龄发生改变ꎬ以及影响不同林龄的关
            2023)ꎮ 已有研究报道了对沙地樟子松生长具有                           键气候因子是否存在差异ꎬ有待进一步探索ꎮ

            显著影响的降水和温度的月份( Song et al.ꎬ 2017ꎻ                      本文以辽宁章古台樟子松中龄林(33 a)、成
            Sun et al.ꎬ 2021)ꎬ但受研究方法或所选样本的影                    熟林(48 a)和过熟林(64 a) 为例ꎬ利用树木年轮
            响ꎬ不同研究最终确定的月份存在差异ꎮ 同时ꎬ这                            学方法ꎬ旨在探讨以下 3 个问题:(1) 樟子松生长
            些研究没有明确对树木生长影响最强的温度和降                              速度和趋势的林龄差异ꎻ(2) 影响不同林龄樟子松
            水因子季节窗口ꎬ导致构建包含气候因子的树木                              径向生长的关键温度和降水发生的季节窗口ꎻ(3)
            生长模型时需考虑的潜在气候变量较多ꎬ而且所                              关键温度和降水因子的相对重要性随林龄变化
            用季节窗口不确定ꎬ在一定程度上增加了模型构                              特征ꎮ
   35   36   37   38   39   40   41   42   43   44   45