Page 19 - 《广西植物》2025年第11期
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11 期           黄振宇等: 入侵与本地菊科植物种子功能特征差异及其对局域扩散的影响                                          1 9 6 3

                 Abstract: To investigate the effect of Asteraceae seed (achene) morphology and functional traits on plant dispersalꎬ we
                 selected nine Asteraceae species (five invasive species and four native species) from the Ailao Mountain area as study
                 species. We measured the density and frequency of each species along roads in the study site using a plot method.
                 Furthermoreꎬ settling velocityꎬ pappus radiusꎬ pappus lengthꎬ seed lengthꎬ seed widthꎬ seed massꎬ seed germination
                 rateꎬ and pappus loading of each species were measured. The results were as follows: (1) Along the surveyed roadsꎬ
                 differences in species frequency were primarily observed among species with no significant differences between invasive
                 and native speciesꎻ howeverꎬ invasive plants exhibited significantly higher plant densities compared to native plants. (2)
                 Regarding seed traitsꎬ invasive plants had a significantly higher germination rate than native plantsꎬ while variations in
                 other seed traits were predominantly species ̄specific. (3) Correlation analysis showed that no significant correlation was
                 found between seed germination rate and seed massꎬ whereas seed sedimentation velocity was significantly correlated with
                 seed length and widthꎬ and pappus loading. (4) Correlations between seed traits differed between invasive and native
                 plants. For instanceꎬ among native speciesꎬ seed germination rate was negatively correlated with sedimentation velocityꎬ
                 but this trade ̄off was not observed in invasive speciesꎬ indicating differing seed ecological strategies between invasive
                 and native plants. (5) For all tested Asteraceae plantsꎬ species density was significantly positively correlated with seed
                 germination rateꎬ and no significant correlation was found between species frequency and seed traits. These results
                 suggest that seed morphological traits significantly influence seed dispersal potentialꎬ yet they do not fully reflect the
                 actual dispersal outcomes. The higher seed germination rates of invasive Asteraceae plants is an important reason for their
                 high field density formation.
                 Key words: Asteraceaeꎬ invasive plantsꎬ seed morphological traitsꎬ pappus characteristicsꎬ seed dispersal




                种子作为植物繁殖与扩散的关键器官ꎬ其传                            型的种子在入侵植物与本地植物之间的特征差异
            播过程在植物生态学研究中具有重要意义ꎮ 种子                             难以通过单一性状加以概括ꎮ 植物功能性状之间
            的传播策略与植物的分布格局密切相关ꎬ尤其是                              的相互关系是其协同进化的结果ꎬ塑造植物的表
            对积极向新区域扩张的入侵物种更为显著ꎮ 种子                             型整 合 模 式ꎬ 反 映 了 物 种 的 生 态 策 略 ( Legras et
            的扩散能力与其特征密切相关ꎬ包括种子的大小                              al.ꎬ 2020ꎻ Sobralꎬ 2021)ꎮ 种子特征之间亦表现
            和质量等(Tamme et al.ꎬ 2014)ꎮ 种子质量不仅影                  出类似的 相 关 性ꎮ 然 而ꎬ也 有 研 究 指 出ꎬ种 子 质
            响植物的定殖能力、竞争能力ꎬ而且还影响扩散能                             量、萌发率与扩散能力之间并不总是呈现权衡关
            力(Chen et al.ꎬ 2018ꎻ Bu et al.ꎬ 2019)ꎮ 通常情况        系ꎮ 例如ꎬ入侵植物豚草能够打破传统权衡机制ꎬ
            下ꎬ大种子具有更高的萌发率和幼苗成活率ꎬ但其                             兼具较小的种子质量和较高的萌发率ꎬ在保持高

            传播能力相对较低( Jakobsson & Erikssonꎬ 2003ꎻ              繁殖潜力的同时不牺牲传播能力ꎬ从而实现扩散
            Morin & Chuineꎬ 2006ꎻ Hahn et al.ꎬ 2013)ꎮ 此外ꎬ      与定殖两个阶段的优势(Zhou et al.ꎬ 2021)ꎮ 这些
            大种子在形成和传播过程中均需消耗更多的能量                              研究结果表明了种子特征及其共变关系对植物扩

            资 源 ( Mukherjee et al.ꎬ 2019ꎻ Akaffou et al.ꎬ      散效果的重要影响ꎮ
            2021)ꎮ 种子传播附属结构有助于提升种子的传                               种子传播体结构和形态特征对种子的传播效
            播效率ꎮ Murray 和 Phillips(2010) 研究表明ꎬ种子               率具有重要的影响ꎮ 在各类种子中ꎬ风媒种子( 如
            传播附属物的投资程度与其地理分布范围呈正相                              带有 冠 毛 的 种 子) 已 受 到 广 泛 关 注 和 被 研 究
            关ꎬ并且这种现象在引入物种中比本地物种更为                              (Andersenꎬ 1993ꎻ Minami & Azumaꎬ 2003)ꎮ 种子

            普遍ꎬ但也有一些例外情况( Flores ̄Moreno et al.ꎬ                冠毛 形 态 特 征 与 其 传 播 力 密 切 相 关ꎮ Schurr 等
            2013)ꎮ 关于种子大小的研究显示ꎬ在某些生态系                          (2005)通过建立力学模型且结合野外实验发现ꎬ
            统中ꎬ入侵物种的种子大于本地物种( McIntyre et                      附属结构(如冠毛、翅、伞状结构) 能够有效降低起
            al.ꎬ 2005ꎻ Daws et al.ꎬ 2007)ꎬ而在其他生态系统             动风速、提高风拦截效率ꎬ并调节其与障碍物交互
            中则 表 现 为 更 小 ( Cadotte & Lovett ̄Doustꎬ 2001ꎻ       作用ꎬ 从 而 显 著 提 升 种 子 的 地 表 传 播 能 力ꎮ
            Maron et al.ꎬ 2012)ꎮ 由于植物种类多样ꎬ不同类                  Cummins 等(2018) 通过流体力学实验证实ꎬ蒲公
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