【作者】 李荣生；

【导师】 许煌灿； 黄世能； 徐大平；

【作者基本信息】 中国林业科学研究院 ， 森林培育， 2003， 博士

【摘要】 棕榈藤是棕榈科的藤本植物，天然分布于热带和亚热带森林中，其生长对水分要求较高，据研究，水分是棕榈藤生长的第一影响因子。但在现实林业生产中，由于全球温室气体的大量排放、大气侯的变化、季节变换、坡位差异和人为活动干扰等因素的影响，棕榈藤人工林在生长过程中不可避免地会遭遇供水不足甚至干旱的情况，从而降低藤林产量，给藤林经营者造成损失。因此如何减少甚至避免供水不足或干旱带来的产量损失成为人们关注的焦点。采取集约经营和其它造林措施可以减少甚至避免供水不足或干旱对藤林生长的影响，减低藤林经营者的损失，但这些措施劳动强度大而且成本很高；而如果能够选用抗旱能力强和水分利用效率高的藤种，则可以避免上述不足。基于上述目的，本论文选择黄藤、单叶省藤和白藤等3种我国主要栽培藤种为研究对象，研究这3个藤种的抗旱能力和水分利用效率，研究结果将为营林藤种的选择和藤林的经营提供理论依据和指导，对于提高藤林经营管理水平和产量具有现实的指导意义。 在3个棕榈藤种的水分利用效率方面，论文首先通过测定3个藤种苗木和成年植株的有关生理指标，结果表明黄藤、单叶省藤和白藤等3个藤种苗木和成年植株的叶绿素a/b值、叶片上下表面气孔数比、磷酸烯醇式丙酮酸羧化酶（PEPCase）活性、丙酮酸磷酸双激酶（PPDK）活性和稳定碳同位素比等指标与其它C3植物相近，而与常见C4植物差别很大，因此作者认为黄藤、单叶省藤和白藤等3个藤种是C3植物。根据前人研究，稳定碳同位素比可作为衡量C3植物水分利用效率高低的指标，因此本研究将其应用到广东省金鸡坑林场1990年营造的杉藤混交林中3个藤种水分利用效率的比较上，通过测定杉藤混交林中3个藤种的叶片稳定碳同位素比，结果表明单叶省藤叶片稳定碳同位素比最，黄藤次之，白藤最小，这也意味着单叶省藤水分利用<WP=3>效率最高，黄藤次之，白藤最小。随后对3个藤种的生长情况进行调查，结果表明，单叶省藤藤茎生物量最大，黄藤次之，白藤最小。综合杉藤混交林的调查结果，可以得到水分利用效率高的棕榈藤种在同样生长环境下具有较高的藤茎产量的结论。此外，通过苗木盆栽试验结果表明，18个月生的单叶省藤苗木水分利用效率高于18个月生的黄藤苗木，18个月生的黄藤苗木水分利用效率高于8个月生的白藤苗木。 在3个棕榈藤种的抗旱能力方面，通过苗木盆栽试验，结果表明18个月生的黄藤苗木生长所需的临界土壤含水量与18个月生的单叶省藤苗木相当，但两者均高于8个月生的白藤苗木。而耐旱试验表明，虽然在湿区生长的黄藤和单叶省藤苗木没有死亡，但黄藤苗木在自然干旱处理一段时间后死亡株数和死亡率比单叶省藤高，而试验期间内白藤苗木在旱区和湿区均有苗木死亡，且湿区死亡株数还略高于旱区。因此作者认为，8个月生的白藤苗木抗旱高于黄藤苗木和单叶省藤苗木；18个月生的单叶省藤苗木抗旱能力高于同样年龄的黄藤苗木。根据这种试验结果，作者建议在林业生产中，不要供给白藤苗木太多的水，但要给黄藤和单叶省藤充足的水分。同时联系结论2，作者认为抗旱能力高的藤种其水分利用效率不一定高。 此外，在3个藤种苗木水分利用效率试验中还发现，随着土壤相对含水量的减少，3个藤种苗木的水分利用效率会呈现出上升或下降的变化，虽然它们变化原因是不一样的，但都有一种趋势，就是当土壤相对含水量降低到70%以后，虽然水分利用效率有所提高，但苗木制造的干物质量开始下降，即产量可能发生下降，这是林业生产所不愿看到的；而当土壤相对含水量上升到70%以后，水分利用效率开始下降，而且苗木制造的干物质量没什么变化，这意味着供给更多的水也只是浪费。因此建议林业生产上要加以人工调节，以避免干旱或供水过多，以减少干旱降低产量或供水过多浪费水资源。更多还原

【Abstract】 Rattan is a group of climbing plants belonging to the family of Palmae, occurring naturally in different forests in tropical and subtropical areas. As its habitat implying, rattan grows well when water supply is plentiful. It was also reported that water is the most important factor controlling rattan growth. However, the productivity of rattan plantations is reduced for occurrence of deficiency of water or drought inevitably caused by green-house gas emission, changes of climate and season, sites and human activities. How to minimize the decrease of productivity caused by water deficiency or drought is the essential for rattan plantation industry. Intensive management and other sylviculture methods can resolve the problem to some extent,<WP=5>but it is hard and expensive. To select the drought resistance species with a high water use efficiency is the alternative way which resolve the problem without intensive management or other sylviculture actions. This paper is to select such sought-after rattan species by comparisons of drought resistance and water use efficiency of Daemonorops margaritae, Calamus simplicifolius and C. tetradactylus, which are widely used rattan species. Completely randomized block designs was used in the experiment of studying drought resistance of three rattan species, with soil water content 45.0±5%, 57.5±5%, 70.0±5%, 82.5±5% and 95.0±5% of field capacity. The data about recruitment leaf, length of plant part above ground-level, length of root and biomass of each seedling were measured and processed by analysis of variance and tested by q test. The results showed that significant difference occurred in the length of D. margaritae above ground plant and the length of C. simplicifolius root when the soil water content decreased from 95.0±5% to 82.5±5% of field capacity, so did other indices when soil water content decreased further to 70.0±5%. However, differences were not significant in any indices of C. tetradactylus<WP=6>seedlings growing under different water regimes. It was concluded from above that drought resistance of D. margaritae seedlings is similar to that of C. simplicifolius seddlings, but both are inferior to that of C. tetradactylus seedlings. Another experiment was carried out to investigate seedlings grown with two water regimes, one was to water seedlings everyday to keep soil moisture, the other was not to water at all. The results showed that C. tetradactylus seedlings watered everyday died as well as those not watered at all, and even the number of dead seedlings grown with water was higher than that of dead seedlings grown without water. D. margaritae seedlings grown without water had a higher mortality than C. simplicifolius seedlings. Thus together with results from the last paragraph, it was concluded that the seedlings of C. tetradactylus was more tolerance to water drought than the seedlings of C. simplicifolius and D. margaritae, D. margaritae seedlings was less tolerance to water drought than C. simplicifolius seedlings. Water use efficiency of three rattan species was studied as following. Firstly, indices of chlorophyll a/b, ratio of stomata on top<WP=7>surface to that on below surface, PEPCase, PPDK and isotopic carbon ratio were assayed and the results showed that the three rattan species were plant with C3 photosynthesis pathway, which was the basis for employing isotopic carbon ratio in comparing water use efficiency between rattan species. Secondly, based on the experiment conducted for comparison of drought resistance, the isotopic carbon ratio of both the leaves and roots of seedlings, the biomass and its consumption of water of the seedlings were recorded and assayed, the results showed that water use efficiency of C. simplicifolius seedlings was a little higher than that of D. margaritae, but both were larger than that of C. tetradactylus. Both isotopic carbon ratio of leaves and roots were relevant positively to the water use efficiency of rattan seedlings, however, the isotopic carbon ratio of leaves was更多还原