Page 78 - 《广西植物》2026年第7期
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1 1 7 4 广 西 植 物 46 卷
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CHEN Fengfan ꎬ YANG Zhe ꎬ JIANG Haidu ꎬ WANG Yong ꎬ LIU Xiongsheng ꎬ
2 2ꎬ3 2∗ 2
PENG Lihui ꎬ WEI Lingzhi ꎬ CHAI Shengfeng ꎬ WEI Xiao
( 1. Guangxi Forestry Research Instituteꎬ Nanning 530002ꎬ Chinaꎻ 2. Guangxi Institute of Botanyꎬ Guangxi Zhuang Autonomous
Region and Chinese Academy of Sciencesꎬ Guilin 541006ꎬ Guangxiꎬ Chinaꎻ 3. College of Tourism and
Landscape Architectureꎬ Guilin University of Technologyꎬ Guilin 541006ꎬ Guangxiꎬ China )
Abstract: Craigia yunnanensisꎬ a plant species with extremely small populations (PSESP) endemic to Chinaꎬ is listed
as a National ClassⅡprotected wild plant. To clarify the causes of regeneration failure — particularly the lack of sapling
recruitment in natural populations — this study compared the photosynthetic characteristicsꎬ photosynthetic pigment
contentsꎬ leaf epidermal traitsꎬ leaf anatomical structuresꎬ and leaf functional traits between seedlings (6 ̄month ̄old)
and young trees (8 ̄year ̄old) cultivated in an experimental plantation. The results were as follows: (1) The maximum
 ̄2  ̄1  ̄2  ̄1
net photosynthetic rate (12.00 μmolm s ) and light saturation point (1 360.40 μmolm s ) of young trees
 ̄2  ̄1  ̄2
were extremely significantly higher (P<0.01) than those of seedlings (5.69 μmolm s and 839.61 μmolm
 ̄1  ̄2  ̄1
s ꎬ respectively)ꎬ whereas the light compensation point of seedlings was lower (11.37 μmolm s )ꎬ indicating a
shade ̄tolerant strategy in seedlings and a light ̄demanding strategy in young trees. (2) Chlorophyll and carotenoid
contents in young trees were significantly or extremely significantly (P<0.05 or P<0.01) higher than those in seedlingsꎬ
and their leaves were thickerꎬ with more developed palisade tissuesꎬ larger midrib vessel diametersꎬ and bigger leaf
areaꎬ higher specific leaf weightꎬ and leaf dry matter content. (3) Correlation analysis revealed significant (P<0.05) or
extremely significant ( P < 0.01) positive correlations between maximum net photosynthetic rate and leaf thicknessꎬ
chlorophyll contentꎬ specific leaf weightꎬ and leaf dry matter. In conclusionꎬ seedlings adapt to low ̄light understory
environmentsꎬ whereas young trees require higher light availability to sustain their elevated photosynthetic capacity.
Insufficient understory light in natural habitats likely hinders the transition from seedlings to young treesꎬ contributing to
the species’ endangered status. These findings provide essential scientific support for conservation and cultivation
practices. It is recommended that thinning or canopy ̄opening measures be implemented to improve understory light
conditions and promote population regeneration.
Key words: Craigia yunnanensisꎬ extremely small populationꎬ photosynthetic characteristicsꎬ leaf anatomical
structureꎬ chlorophyll
极小种群物种是生物多样性保护的重中之 模式种ꎬ其在植物系统演化研究中占据关键地位ꎬ
重ꎬ其生存状况直接关系到生态系统的完整性和 具有 重 要 的 科 学 研 究 价 值 ( 应 俊 生 和 张 玉 龙ꎬ
稳定性ꎮ 开展此类物种的保护研究ꎬ对于防范物 1994)ꎮ 然而ꎬ受分布区狭窄、生境片段化严重以
种灭绝、保护我国特有的生物遗传资源具有重大 及人为干扰等因素影响ꎬ滇桐野生种群数量持续
战略意义(臧润国等ꎬ2016ꎻ许玥和臧润国ꎬ2022)ꎮ 减少ꎬ呈现明显的衰退趋势ꎮ 野外调查显示ꎬ现存
滇桐(Craigia yunnanensis) 作为我国特有的极小种 种群多呈零星间断分布ꎬ且普遍存在“ 有大树、见
群野生植物ꎬ被列为国家二级重点保护野生植物 幼苗、缺幼树”的更新断档现象(叶红环等ꎬ2022)ꎬ
(国家林业和草原局 农业农村部ꎬ2021)ꎮ 该物种 表明其自然更新过程存在严重障碍ꎮ 这种更新障
主要分布于云南、广西、贵州等地的南亚热带常绿 碍不仅直接威胁种群的可持续生存ꎬ也反映了其
阔叶林区ꎬ常见于海拔 1 000 ~ 1 500 m 的山坡下 生活史过程中可能存在某些关键限制因子ꎮ 因
部、山脚和山谷地带( Tang et al.ꎬ 2007)ꎮ 滇桐树 此ꎬ深入研究滇桐幼苗与幼树的生理生态特性ꎬ揭
干通直ꎬ树体高大ꎬ材色美观ꎬ材质坚硬且耐磨ꎬ加 示其更新障碍的关键影响因子ꎬ对制定有效的保
工性能良好ꎬ是具有重要经济价值的珍贵用材树 护策略具有重要意义ꎮ
种ꎮ 同时ꎬ该物种对石灰岩岩溶生境表现出特殊 光合作用是植物生长发育的基础ꎬ也是植物
的适应性ꎬ是石漠化地区生态恢复的优良树种( 中 生长的重要生理过程ꎬ可根据植物光合特性确定
国科学院昆明植物研究所ꎬ2006)ꎮ 作为滇桐属的 其 最 适 宜 的 生 长 环 境 和 生 态 条 件 ( Adamecꎬ

