地形异质性对尖峰岭热带山地雨林木本植物群落数量特征的影响

发布时间：2018-04-03 22:29

  本文选题：尖峰岭　切入点：热带山地雨林　出处：《中国林业科学研究院》2017年硕士论文

【摘要】：物种分布与共存一直是群落生态学研究的核心内容,评估各种环境因子对物种空间分布与共存的相对贡献越来越受到重视。本文以海南尖峰岭60 hm~2热带山地雨林原始林动态监测样地(大样地)首次调查数据为基础,通过对样地1500个20 m×20 m样方的平均海拔、坡度和凹凸度3个地形指标进行C-均值模糊聚类,将大样地划分为低海拔沟谷、陡坡、高海拔沟谷、山脊4等种地形类型;分析了不同地形条件下森林群落组成结构、物种多样性、地上部分生物量等数量特征的差异性;基于Torus转换检验,从多度和生物量两个方面比较了230种常见物种分布与地形的关联性;并以42种优势冠层乔木物种为对象,初步探讨不同生长阶段物种分布与地形的关联的变化规律;以期为进一步揭示热带森林物种的分布与共存规律提供科学依据。主要研究结果如下:(1)山脊与陡坡各径级植株密度都显著大于低海拔沟谷和高海拔沟谷(P0.05),这与山脊和陡坡较强的光照有关。山脊与陡坡阳生树种重要值更大,阴生树种柏拉木(Blastus cochinchinesis)、变色山槟榔(Pinanga baviensis)由于其耐阴特性出现在低海拔沟谷与高海拔沟谷重要值前10的物种中,但在陡坡和山脊中并未出现。表明光照可能是因地形条件不同而进一步影响尖峰岭大样地植物分布的一个关键环境因子。20 m×20 m样方尺度上,山脊与陡坡地形的物种丰富度及Shannon-Wienner指数显著高于低海拔沟谷和高海拔沟谷(P0.05),但两类沟谷地形之间、两类非沟谷地形之间则无显著差异(P0.05)。从Simpson指数来看,两类非沟谷地形显著大于高海拔沟谷;低海拔沟谷显著低于其他3类地形(P0.05)。Pielou's均匀度指数在陡坡中最大,而在低海拔沟谷中最低,两类非沟谷地形显著高于两类沟谷地形(P0.05)。种—面积曲线表明,当取样面积大于5000 m~2时,随着取样面积增加,同等面积条件下,低海拔沟谷的物种数始终最大,其他3类地形物种数基本位于陡坡地形估计值的±1.96íSE置信区间内,其种—面积曲线无明显差异;种—个体数累积曲线表明,随着取样个体数增加,低海拔沟谷物种累积速率最大。大样地中木本植物层的地上部分生物量、总生物量和碳库分别为368.8 Mg·hm~(-2)、457.3 Mg·hm~(-2)、228.6 Mg·hm~(-2),表明尖峰岭热带山地雨林具有较高的森林生物量;低海拔沟谷的地上部分生物量(322.3 Mg·hm~(-2))、总生物量(399.5 Mg·hm~(-2))与碳库(200.0 Mg·hm~(-2))最小;山脊地形中均最大,对应为408.5 Mg·hm~(-2)、506.5 Mg·hm~(-2)、253.3 Mg·hm~(-2);山脊与陡坡地上部分生物量、总生物量及碳库均显著大于低海拔沟谷和高海拔沟谷(P0.05)。(2)以230种常见种(胸径不小于1 cm的植株且种群独立植株数60)为研究对象,基于Torus转换检验,从物种多度这一群落数量指标来看,90%的物种与地形显著相关;地形导致的生境异质性对物种分布与共存贡献率为24.5%。从生物量这一数量指标来看,74.8%的物种与地形显著相关,地形导致的生境异质性对物种分布与共存贡献率为19.7%。基于物种多度和生物量两个方面,其与地形的显著相关的物种数显著不同,某地形中多度大的物种并非意味着大的生物量,反之亦然。因此研究环境因子对物种共存的影响时,应从不同角度考虑并进行对比分析。(3)以4类地形中各自生物量排序前30的优势冠层乔木物种(共42种)为对象,从不同生长阶段检验其与地形的关联性,结果表明基于多度指标,幼树、中龄树和成年树阶段与地形正相关的物种数分别为28、34、24,基于生物量指标,对应的种数为28、32、23;基于多度,幼树阶段、中龄树阶段、成年树阶段地形生境异质性对42种冠层乔木分布与共存的贡献分别为23.2%、29.2%、13.1%,基于生物量对应值为20.8%、28.0%、11.3%,贡献率均先增加后减少。幼树阶段物种与某地形的正相关或负相关的较大部分能够保持到中龄树阶段,但只有较少部分能够保持到成年树阶段,表明物种在不同生长阶段的生存策略不同。幼树至中龄树阶段,受地形条件及相应的水热等环境因子限制,物种主要受生境过滤的影响,进入成年树阶段,生态位分化则逐步起主导作用。
[Abstract]:Species distribution and coexistence has been the core contents of ecology, evaluation of various environmental factors on the relative contribution and spatial distribution of species coexistence and more attention. In this paper, 60 hm~2 tropical montane rainforest in Jianfengling of Hainan original forest dynamic plot (sample) first survey data as the foundation, through the average altitude on the sample 1500 a 20 m * 20 m plots, slope and roughness 3 topographic index C- fuzzy c-means clustering, the sample will be divided into low altitude valleys, steep slopes, high altitude ridge Valley, 4 types of terrain; analyzed the structure of forest communities under different terrain conditions, species diversity, different quantitative characteristics aboveground biomass; Torus conversion based on inspection, from the two aspects of abundance and biomass compared 230 common species distribution and the topography of the Association; and 42 species of arbor canopy advantage Like, preliminary to study the changes of related species distribution in different growth stages and terrain; so as to provide scientific basis for exploring the rules of distribution and coexistence of tropical forest species. The main results are as follows: (1) the ridge and slope of each diameter class plant density is significantly greater than the low altitude and high altitude gully Valley (P0.05). This strong and steep ridges and light. Ridges and steep heliophilousis species important values, shade tree species (Blastus cochinchinesis) Blastus, areca (Pinanga baviensis) discoloration due to its shade tolerance characteristics appear in low altitude and high altitude gully gully important value of 10 species, but did not appear in the the steep slope and ridge. The results showed that light may be due to different terrain conditions and further affect the distribution of several plants in a key environmental factor.20 m * 20 m scale, ridges and steep terrain. Species richness and Shannon-Wienner index were significantly higher than those of low altitude and high altitude gully Valley (P0.05), but two kinds of valley terrain between between the two types of non valley terrain showed no significant difference (P0.05). From the Simpson index, two kinds of non valley terrain was significantly greater than that in high altitude valleys; low altitude valley was significantly lower than that of the other 3 types of terrain (P0.05).Pielou's evenness index maximum on steep slopes, and in the low altitude Valley in the lowest, two non valley terrain was significantly higher than that of two kinds of valley terrain (P0.05). The species area curve shows that, when the sampling area is more than 5000 m~2, with the increasing sampling area, the condition of the same area, the low altitude valley. The species are always the biggest, the other 3 types of terrain species basically located in steep terrain to estimate the value of + 1.96 SE confidence interval, the species area curve had no significant difference; a cumulative number of individual curves show that with the sample number 澧炲姞,浣庢捣鎷旀矡璋风墿绉嶇疮绉�椋�

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