The Effects of Light Quality and Quantity on the Developmental Ecology of Malaysian Rainforest Trees

地球上现存的热带雨林在未来10年将面临毁灭的威胁。其机制是农业转型、转向牧场、全球气候变化、工业化农业和伐木，其原因是人口过剩和短视。帮助这些森林再生和恢复的知识大多是缺乏的。特别是需要详细了解决定这些森林中单个树种生长的环境因素。不同的树木对森林荫蔽条件的耐受性不同，从而控制了这些树木的再生模式。生长在森林自然树荫下的树木会受到光强度降低和光的光谱质量变化的影响。在不考虑光质量变化的情况下，几乎所有树木的遮荫响应都被研究过。因此，以往对树木遮荫响应的研究可能低估了树木对遮荫条件的响应。这一建议的目的是研究光质量变化的影响独立于光强的降低，植物暴露在森林荫凉。马来西亚吉隆坡林业研究所将在专门建造的荫蔽室内研究十种马来西亚热带雨林树木幼苗对光照数量和光照质量的反应。这些树木将包括先锋树种、耐阴新生树种和不耐阴新生树种。这些幼苗将种植12个月，然后对它们的结构、叶片形态和解剖结构以及光合特性进行分析。这些结果将与在自然树冠树荫下生长的幼苗的结果进行比较，并将有助于了解这些树木如何对森林中的自然光气候做出反应。这些信息也可以用来帮助在苗圃中种植它们，以便以后移植到再生森林中。

The earth's remaining tropical rainforests are threatened with destruction in the next 10 years. The mechanisms are shifting agriculture, conversion to pasture, global climate changes, industrial agriculture and logging, and the reasons are over-population and short-sightedness. Knowledge which would assist in the regeneration and restoration of these forests is mostly lacking. In particular detailed knowledge of the environmental factors that determine the growth of the individual tree species in these forests is needed. Different trees vary in their tolerance to shade conditions in the forest, controlling the patterns of regeneration of these trees. Trees growing in the natural shade of forests are subjected to a reduction in light intensity and a change in the spectral quality of the light. Virtually all of the shade responses of tree have been studied at varying light levels without regard to these shifts in light quality. Thus, previous studies on shade responses of trees probably underestimate responses of trees to shade conditions. The purpose of this proposal is to study the effects of shifts in light quality independently of the reduced light intensity to which plants are exposed in the forest shade. The responses of seedlings of ten Malaysian rainforest trees to light quantity and quality will be studied in specially constructed shadehouses at the Forestry Research Institute in Kuala Lumpur, Malaysia. These trees will include pioneer species, shade-tolerant emergent and shade-intolerant emergent. The seedlings will be grown for twelve months and then be analysed for their architecture, leaf morphology and anatomy, and photosynthetic properties. The results will be compared to those from seedlings grown under natural canopy shade, and will help in understanding how these trees respond to natural light climates in the forest. Such information can also be used to help grow them in nurseries for later transplanting into regenerating forests.