任豆林的生物量和光能利用率

 本文研究了粤北石灰岩地区以任豆(Zenia insignis)为主的自然林(萌生34年)的生产能力，并与任豆人工林(6年生)作对照。结果表明，在1992年7月调查时，自然林和人工林的现存生物量分别是125.38和10.34t·hm-2；平均增长量为3.69和1.72t·hm-2·a-1；木材蓄积量为86.35和9.93m3·hm-2；其乔木层总生产力为84284和21510kJ·m-2·a-1；对光合有效辐射能的利用效率为5.43％和1.39％。反映了任豆自然林现存生物量和生产力比鼎湖山南亚热带常绿阔叶林(同龄萌生林，在1991年11月调查)现存生物量196t·hm-2低，而比热带和亚热带半干早区森林植物量分别107和98.7t·hm-2高。任豆人工林因盖度和叶面积指数比自然林低，故总生产力和光能利用率也比较低，说明任豆人工林尚有较高的生产潜力。

THE BIOMASS AND SOLAR ENERGY UTILIZATION EFFICIENCYIN ZENIA INSIGNIS FOREST

The productive capacity of the natural forests that dominated by Zenia insignis in North Guangdong limestone region was investigated, and compared to that of a 6-year-old artificial Zenia insignis forest. The results show that the biomass, stocking, increment, gross primary productivity of arbour layer and PAR energy use efficiency in the natural forest in natural Zenia insignis forest was 125.38t·hm-2, 86.35m3·hm-2,3.69t·hm-2,84284kJ·m-2·a-1 and 1.39%,respectively, suggesting that its biomass and productivity were lower than those of the evergreen broad leaf forest in humid region [1 ,2,10], but were higher than those of forest in subtropical semi-arid region [9]. The photosynthesis rates of Zenia insignis was higher, but the crown density and leaf area index of artificial forest was lower as compared to those of natural forest. So the gross productivity and solar energy utilization ratio of the artificial forest was low. All above indicate the higher productivity potential of the artificial forest.