Van der Heyden F, Stock W D
Department of Botany, University of Cape Town, Private Bag, 7700, Rondebosch, South Africa.
Oecologia. 1995 May;102(2):238-245. doi: 10.1007/BF00333256.
Nonstructural carbohydrate allocation patterns in response to different frequencies of simulated browsing (leaf and twig removal) were studied in the following semi-arid shrubs: Osteospermum sinuatum, a dwarf deciduous shrub, Pteronia pallens, a dwarf evergreen shrub, and Ruschia spinosa, a dwarf leaf-succulent shrub. Simulated browsing at all frequencies resulted in the elevation, or had no effect, on total nonstructural carbohydrate (TNC) concentrations of O. sinuatum plant parts, and resulted in the decrease in TNC concentrations of R. spinosa plant parts. The responses of P. pallens were intermediate with elevations as well as declines in TNC concentrations of plant parts measured in response to various clipping frequencies. At the low frequency of simulated browsing (every 26 weeks) elevations in plant TNC content were measured in the two non-succulent shrubs O. sinuatum and P. pallens. It was concluded that the overcompensation with respect to TNC accumulation observed in the two non-succulent species represents one of the ways in which excess photosynthate is utilized by browsed shrubs with a limited regiowth potential. Simulated browsing was the least detrimental with respect to biomass production to the non-succulent O. sinuatum and P. pallens, and most injurious to the leaf-succulent shrub, R. spinosa. The observed TNC allocation patterns could not adequately explain the variation among species in the production of new growth and it was concluded that some factor(s) other than the carbon resource was limiting regrowth.
在以下半干旱灌木中研究了非结构性碳水化合物分配模式对不同频率模拟啃食（去除叶片和嫩枝）的响应：矮生落叶灌木南非万寿菊（Osteospermum sinuatum）、矮生常绿灌木苍白翼菊（Pteronia pallens）和矮生肉质叶灌木刺露子花（Ruschia spinosa）。所有频率的模拟啃食导致南非万寿菊植物各部分的总非结构性碳水化合物（TNC）浓度升高或无影响，导致刺露子花植物各部分的TNC浓度降低。苍白翼菊的响应处于中间状态，其植物各部分的TNC浓度在响应不同修剪频率时既有升高也有下降。在模拟啃食的低频（每26周一次）时，在两种非肉质灌木南非万寿菊和苍白翼菊中测量到植物TNC含量升高。得出的结论是，在两种非肉质物种中观察到的TNC积累的超补偿代表了具有有限区域生长潜力的被啃食灌木利用过量光合产物的方式之一。模拟啃食对非肉质的南非万寿菊和苍白翼菊的生物量生产危害最小，对肉质叶灌木刺露子花危害最大。观察到的TNC分配模式无法充分解释物种间新生长产量的差异，得出的结论是，除碳资源外的某些因素限制了再生。
