【作者】 王辉；

【导师】 张硕新；

【作者基本信息】 西北农林科技大学 ， 生态学， 2008， 硕士

【摘要】 本文研究了西双版纳热带几种常见不同生态习性树种幼苗在不同光照和营养梯度下以及热带雨林耐荫顶极种玉蕊幼苗在不同光照梯度、不同环境、不同季节的生物量分配特征、结构特征、各器官TNC浓度与分配状况对植物幼苗受干扰破坏后萌生状况的影响。结果表明:1.耐荫性较强的玉蕊、翅子树具有较强的萌生能力,耐荫性很差的先锋种萌生能力很差,石灰山基质发育起来的尖叶闭花木萌生能力也较差。随着树种耐荫性的增加,萌生能力在逐渐增强。2.不论是耐荫的顶级种还是不耐荫的先锋种,在受干扰后在较高光强下的萌生能力都要显著高于在低光下的水平;树种的耐荫性越弱,受干扰后的萌生反应对光照的响应越敏感;玉蕊的萌生能力随着光照的减弱而降低。3.除不耐荫的先锋种团花和山黄麻在干扰后全部死亡以外,中平树在高光低肥处理组下也仅有20%的萌生率。高光下,其它几个耐荫树种在低肥处理组下的萌生能力显著高于高肥处理组的个体,但在低光下萌生成功率和其他萌生特征在营养梯度间的差异不显著。4.高光低肥处理组下所有树种都有着最高的萌生系数,高光低肥处理能显著提高树种的萌生能力。5.不论何种环境条件下,雾凉季干扰后玉蕊的萌生能力最强,干热季居中,而雨季干扰后的萌生能力最差。6.在野外三种不同环境下,不论那个季节大林窗环境中的个体都产生了最多的萌条数量、最大的萌枝总长和最大萌枝长度,因而大林窗中的个体拥有着最强的萌生能力。小林窗中的个体次之,生长在阴暗林下环境中个体的萌生能力最差。玉蕊在林窗中的萌生能力也随着林窗地面阳光有效性的降低而减弱。7.本文所观测的反映树种萌生能力的大多数指标与干扰后的残桩地径(OD)和干扰前个体的叶面积比(LAR)呈显著的正相关关系,但与非结构性碳水化合物在根系的分配比例(Percent of TNC allocation to root)、根生物量比(RMR)、根冠比(R/C)呈显著的负相关关系;但根系以及其他各器官中非结构性碳水化合物浓度水平(TNC concentration)、叶生物量比(LMR)、茎生物量比(SMR)、比叶面积(SLA)及TNC在叶和茎中的分配比例与树种萌生能力指标之间的相关性不显著。8.萌生叶片数量(NRL)、最大萌枝长度(MXRL)、总萌枝长度(TRL)、平均萌枝长度(MERL)以及总萌枝地径(TRBD)和最大萌枝地径(MRBD)对大多数影响萌生能力的因素的响应都非常显著,它们是反映萌生状况的重要评判指标。但相关性分析结果表明萌枝数量(NRB)、萌枝成功率(RR)以及最大萌枝地径与原始地径比(M/O-BD)三个指标与影响萌生的因素之间的相关性不显著。更多还原

【Abstract】 Six tropical woody species seedlings with different ecology habits were studied under two light and nutrient gradients on biomass allocation, structural characteristics, non-structure carbohydrate concentration and allocation in different organs and theirs effects on the subsequence re-sprouting ability after disturbance. The re-sprouting behaviors of shade tolerance climax tropical forest seedling--Barringtonia macrostachya was also studied under four different light gradients and under three different size of forest-gap in three different seasons. The results showed that:1.The shade-tolerance climax species B. macrostachya and Pterosperma lanceaefolium had higher re-sprouting capability than those of pioneers and the lime substrate specialization species. With the increase of shade tolerance, the re-sprouting ability also increased.2.Whether the shade tolerance climax species or the shade intolerance pioneer species, theirs re-sprouting capability were higher in high light than those in low light. With the decrease of shade tolerance, the capabilities to re-sprouting after disturbance were more sensitive to the decrease of light availability. Under the four light gradients, the re-sprouting ability of B. macrostachya increased with the increase of light availability.3.The shade-intolerance pioneer species Anthocephalus chinensis and Trema tomentosa all died after disturbance. The shade-intolerance species Macaranga denticulata had 20% re-sprouting rate in high-light*low-nutrient treatment, while subjectted a full mortality in other treatments. The other three shade-tolerance species had a higher re-sprouting ability in low nutrient treatment than that in high light, but the difference between nutrient gradients was not significant in low light.4.For all resprouters, high-light*low-nutrient treatment was the best treatment to promote their capability to re-sprouting.5.In the field, the cool season’s disturbance induced highest re-sprouting ability, followed by dry season, while rainy season was lowest.6.For any season, the big forest gap individuals produced the highest number of leaf, maximum number of re-sprouted stem, maximum re-sprouted branch length hence theirs contribution to re-sprouting ability. Followed by small forest gap and under-story environment. The sprouting capability decreased with the decrease of ground light availability. 7.Most of the re-sprouting indexes studied were positively correlated with the original stump base diameter (OBD) and the individuals leaf area ratio (LAR) previous the disturbance, and negatively correlated with the percent of TNC allocation to root (RTNCa), root mass ratio (RMR) and root-crown mass ratio (R/C). While the concentration of TNC in all organs, leaf mass ratio (LMR), stem mass ratio (SMR) and the percent of TNC allocation to leaf and stem (STNCa, LTNCa) had no correlation with re-sprouting indexes.8.Number of re-sprouted leaf(NRL), total re-sprouted branch length(TRL), maximum re-sprouted branch length(MXRL), mean re-sprouted branch length(MEBL), total re-sprouted stem base diameter(TRBD) and maximum re-sprouted base diameter(MXBD) were significantly respond to most of the factors, which could affect the re-sprouting behaviors potentially. The correlation analysis results showed that number of re-sprouted branch (NRB), re-sprouting successful rate (RR) and maximum re-sprouted base diameter to original base diameter ratio (M/O-BD) had no correlation with most of those factors, which could infulence the re-spouting ability.更多还原