不同光环境下紫椴幼树树冠结构的可塑性响应

摘要/Abstract

摘要： 从冠形、侧枝和叶片在树冠中的空间分布角度对天然更新紫椴幼树的树冠结构进行了论述,认为紫椴幼树树冠对光照条件的变化有显著的可塑性响应.强光通过抑制主干的生长促进了侧枝的分化,庇荫则通过抑制1级侧枝的生长促进了侧枝的再分枝.随着光照水平的降低,紫椴幼树的数量叶片密度显著降低,且叶片逐渐集中于冠上层.林冠下的紫椴幼树通过这种侧枝和叶片的分布格局,在形态上提高其对光的截获能力在适度庇荫环境中,紫椴幼树垂直生长采取演替先锋种的"避荫”对策,侧枝生长采取中等耐荫种的"掠光”对策;在弱光环境中,紫椴幼树则采取典型的忍耐适应行为.这种树冠结构的变化是提高紫椴幼树对光的截获能力的一种有益适应.

关键词: 紫椴, 光, 树冠结构, 幼树, 亚精胺, 渗透调节, 光合特性, 玉米幼苗, 细胞膜透性, 干旱胁迫

Abstract: This paper studied the crown structure of Tilia amurensis saplings,e.g.the shape of crown,and the distribution of branch and leaf.It is shown that the crown structure of the saplings was modified plastically in response to different light conditions.The differentiation of the first order branches was promoted by strong radiation,due to the bole growth being inhibited under high light condition,whereas the bifurcation density of the first order branches whose growth was inhibited by shading was promoted in under canopy environment.The quantitative leaf densities of the saplings obviously decreased with the decrease of light level,while their leaves tented to distribute in upper corwn.The interception of the saplings was enhanced by the distribution pattern of branches and leaves in crown.Under adequate shade condition,the saplings had the strategy of shade avoidance of pioneer species in upward growth,and had the strategy of light forage of moderate shade tolerance in horizontal branch growth.The saplings expressed typically shade tolerant under weak light condition.Such a change of crown structure was an advantageous adaptation for enhancing light interception.

Key words: Tilia amurensis, Light, Crown architecture, Saplings, drought stress, cell membrane permeability., spermidine, maize seedling, osmotic adjustment, photosynthetic characteristics

中图分类号:

S718.42

徐程扬. 不同光环境下紫椴幼树树冠结构的可塑性响应[J]. 应用生态学报, 2001, 12(3): 339-343.

XU Chengyang. Response of structural plasticity of Tilia amurensis sapling crowns to different light conditions[J]. Chinese Journal of Applied Ecology, 2001, 12(3): 339-343.

参考文献

[1] Abrams MD. 1986. Physiological plasticity in water relations and leaf structure of understory versus open-grown Cercis canadensis in northeastern Kansas. Can J For Res, 16:1170～1174

[2] Caham CD. 1988. Growth and canopy architecture of shade-tolerant trees:response to canopy gaps. Ecology, 69(3):786～795

[3] Callawy RM. 1992. Morphological and physiological responses of three California oak species to shade. Int J Plant Sci, 153(3):434～441

[4] Chazdon RL, Kaufmann S. 1993. Plasticity of leaf anatomy of two rainforest shrubs in relation to photosynthetic light acclimation. Funct Ecol, 7:385～394

[5] Chen HTH, Klinka K, Kayahara GJ. 1996. Effects of light on growth,crown architecture, and specific leaf area for naturally established Pinus contorta var. latifolia and Pseudotsuga menziesii var. glauca saplings. Can J For Res, 26:1149～1157

[6] Cornelissen JHC. 1993. Aboveground morphology of shade-tolerant Castanopsis fargesii samplings in response to light environment. Int J Plant Sci, 154(4):481～495

[7] Gillespie AR, Allen HL, Vose JM. 1994. Amount and vertical distribution of foliage of young loblolly pine trees as affected by canopy position and silvicultural treatment. Can J For Res, 24:1337～1344

[8] Gilmore DW, Seymour RS. 1997. Crown architecture of Abies balsamea from four canopy positions. Tree Physiol, 17:71～80

[9] Givnish TJ. 1984. Leaf and canopy adaptations in tropical forests. In:Medina E, Moony HA, Vasquez-Yznez C eds. Physiological Ecology of Plants of the Wet Tropics. Junm, The Hague. 51～84

[10] Givnish TJ. 1988. Adaptation to sun and shade:a whole-plant perspective. Aust J Plant Physiol, 15:63～92

[11] Henry HAL, Aarssen LW. 1997. On the relationship between shade tolerance and shade avoidance strategies in woodland plants. Oikos, 80(3):575～582

[12] Igboanugo ABI. 1990. Effects of shading on shoot morphology, wood production and structure of Quercus petraea. For Ecol Man, 38:27～36

[13] Kozlowski TT, Pallardy SC. 1997. Growth control in woody plants.New York:Academic Press. 97～107

[14] Oliver CD, Larson BC. 1990. Forest stand dynamics. New York:McGraw-Hill, Inc. 41～88

[15] Poulson TL, Platt WJ. 1996. Replacement patterns of beech and sugar maple in Warren Woods, Michigan. Ecology, 77(4):1234～1253

[16] Tucker GF, Lassoie JP, Fahey TJ. 1993. Crown architecture of standgrown sugar maple (Acer saccharum Marsh. ) in the Adirondack Mountains. Tree Physiol, 13:297～310

[17] Veres JS, Pickett ST. 1982. Branching patterns of Lindera benzoin beneath gaps and closed canopies. New Phytol, 91:767～772

[18] Whitehead D et al. 1990. Architectural distribution of foliage in individual Pinus radiata interception. Tree Physiol, 7:135～155

[19] XU C-Y(徐程扬). 1999. Biomass allocation and assimilation efficiency of Tilia amurensis saplings in different light regimes. J For Res, 10(4):1～7(in Chinese)

[20] Ziegenhagen B, Kausch W. 1995. Productivity of young oaks ( Qercus robur L. ) as corresponding to shoot morphology and leaf anatomy.For Ecol Man, 72:97～108