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CAS Workshop on Ecosystem Succession Theory and Practice of Ecological Restoration 植物光合结构与非光合结构的功能平衡： 来自三种亚热带乔木树种的实验证据 曾波 （西南师范大学生命科学学院，重庆
400715） 摘要：植物的地上部分和地下部分存在功能性平衡现已十分清楚，但植物的地上部分是否在其光合结构（叶组织）和非光合结构（枝和茎）之间也存在功能性平衡尚不明晰。本文提出两个研究假设并检验之：（1）
植物地上部分在其光合与非光合结构之间存在功能性平衡；（2）
此功能性平衡的维持依赖于对光合和非光合结构生物量分配的调节。为验证此假设，采用枝叶修剪的方式（连续两年修剪，四个修剪强度：0%，20%，50%，70%）对三种亚热带乔木树种榕（Ficus microcarpa）、黄桷树
(Ficus virens)和樟
(Cinnamomum camphora )）进行了研究。结果表明，修剪使所有树种地上部分的光合与非光合结构生物量比率立即下降，下降程度随修剪强度的升高而增大。但不论是首次修剪还是第二次修剪，修剪处理一年后，修剪株地上部分的光合与非光合结构生物量比率升高，且此生物量比率不低于非修剪株的光合与非光合结构生物量比率。此研究结果证实了植物地上部分光合与非光合结构间存在功能性平衡的假设。与假设一致，植株的生物量分配在修剪后发生了改变：修剪株加大了对光合结构（叶组织）的生物量分配（大量的新生产地上部分生物量被分配到光合结构），同时却减少了对非光合结构（枝和茎）的分配。此分配格局的改变保证了光合与非光合结构功能性平衡的恢复与维持。可以认为，通过改变生物量分配格局以维持光合与非光合结构功能平衡是植物抵御外来干扰和/或损伤的一种有效策略。 关键词：生物量分配；功能平衡；非光合结构；光合结构；乔木 Functional equilibrium between photosynthetic and
aboveground non-photosynthetic structures of plants: evidence from a
pruning experiment with three subtropical tree species Zeng Bo (Faculty of
Life Science, Southwest China Normal University, Chongqing 400715,
China) Abstract:
It is well known that plants have functional equilibriums between
their aboveground parts (shoots) and belowground parts (roots), but
whether the aboveground parts of plants have functional equilibriums
between their photosynthetic structures (leaves) and
non-photosynthetic structures (branches and stem) is unknown. This
paper aims to test the hypotheses that: (a) the aboveground parts of
plants have functional equilibriums between their photosynthetic
structures and non-photosynthetic structures; (b) the maintenance of
the equilibriums is guaranteed by the alteration of biomass
partitioning to photosynthetic and non-photosynthetic structures. To
test these hypotheses, a pruning experiment with four pruning
intensities (0%, 20%, 50%, and 70%) and three subtropical Chinese
tree species (Ficus microcarpa, Ficus virens,
Cinnamomum camphora) was
carried out. Pruning treatments were conducted in two successive
years. In conformity with the hypothesis, the aboveground parts
(shoots) of trees had functional equilibriums between photosynthetic
and non-photosynthetic structures. Pruning decreased instantaneously
the mass ratios of leaves to branches and stem of all tree species,
the reduction in mass ratio was strengthened with pruning intensity.
However, one year after pruning, the mass ratios of leaves to
branches and stem of all pruned trees increased and were not smaller
than those of unpruned trees. In agreement with the expectation, the
biomass partitioning of pruned trees was altered, more newly
produced aboveground biomass was partitioned to leaf growth and less
to branch and stem growth, which enabled the damaged trees to
restore their functional equilibriums between photosynthetic and
non-photosynthetic structures. It is clear that the maintenance of
functional equilibriums between photosynthetic and
non-photosynthetic structures guaranteed by the alteration of
biomass partitioning provides plants a good strategy to resist
external disturbances and damages.
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