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| 1 | 濒危植物水青树的种群结构与数量动态显示文摘以种群生命表及生存分析理论为基础,将林木依胸径大小分级,以林木径级结构代表年龄结构,采用分段匀滑技术,编制四川草坡自然保护区水青树Tetracentron sinense种群特定时间生命表,绘制存活曲线、死亡率曲线、消失率曲线、生存函数曲线,分析种群数量特征;同时结合时间序列模型,分析该种群数量的动态变化。结果表明:(1)草坡自然保护区的水青树的年龄结构表现为稳定型,虽然幼苗较多,但幼树死亡率高,种群处于衰退早期;(2)水青树种群死亡率和消失率曲线变化趋势基本一致,均在第Ⅲ龄级出现一高峰,即幼树死亡率较高;存活曲线趋于Deevey-Ⅱ型;(3) 4个生存函数曲线表明,水青树种群具有前期锐减、中后期相对稳定和末期衰退的特点,其种群处于衰退早期;(4)种群的时间序列预测模型分析表明,在未来9年水青树种群数量将下降,老龄个体逐渐增多,幼龄株数更显不足,呈衰退势态。 | 李文英 李欣 甘小洪 | 2018 | 亚热带植物科学2018，47，3： | 22 |
| 2 | 福建天宝岩国家级自然保护区猴头杜鹃天然种群数量动态和稳定性分析显示文摘对福建天宝岩国家级自然保护区4个猴头杜鹃(Rhododendron simiarum Hance)天然种群进行调查,分析了猴头杜鹃种群的龄级结构、静态生命表、存活曲线和死亡率曲线以及猴头杜鹃林稳定性,并用时间序列模型和动态指数预测猴头杜鹃种群的发展和演变。结果显示:4个猴头杜鹃种群属于增长型和稳定型,基径在2.5 cm及以下的幼苗个体数较多,中高龄级个体数少但分布较均匀。随着龄级的增加,猴头杜鹃种群的生命期望先升高后逐步降低,死亡率则先降低后逐步升高。猴头杜鹃种群的存活曲线大致符合Deevey-Ⅲ型。稳定性分析结果显示:仅猴头杜鹃纯林相对稳定,其他3个猴头杜鹃混交林均不稳定。时间序列预测结果和动态指数显示:猴头杜鹃种群呈现逐步增加、发展稳定的特征;未来中低龄级个体数明显增加,高龄级个体数无明显变化,但易受外部环境影响。总体上看,虽然福建天宝岩国家级自然保护区猴头杜鹃种群呈增长型和稳定型,且生存环境较为稳定,但种群整体面临激烈的生存竞争,幼苗存活率较低,种群结构略失衡。 | 穆振北 陈妍 王李睿 李宁 游巍斌 刘进山 蔡昌棠 何东进 | 2021 | 植物资源与环境学报2021，30，1： | 4 |
| 3 | Plant diversity, population structure, and regeneration status in disturbed tropical forests in Assam, northeast India显示文摘We investigated the plant population structure and the phytosociological and regeneration status in two disturbed tropical forests in Assam Province, the Hojai Reserve Forest and Kumorakata Reserve Forest.A total of 166 species(80 trees, 20 shrubs and 66 herbs) of 136genera and 63 families were recorded in both study sites.The disturbance index at the two sites, Kumorakata Reserve Forest and Hojai Reserve Forest, were recorded at 11.4% and 3.70% respectively.Reverse J-shaped population curve and exploitation of tree species in higher girth classes were recorded at both study sites.In the girth classes(10 30 cm,30 60 cm, 60 90 cm and 90 120 cm in size) the percentage of cut stump density was higher than the percentage of individual living trees.The18%(Kumorakata Reserve Forest) and 7%(Hojai Reserve Forest) species were recorded as 'not regenerating.' Illegal felling and over-exploitation of forest resources may lead to species-specific changes in the population structure and can alter the future structure and composition of the forests. | Gitamani Dutta Ashalata Devi | 2013 | Journal of Forestry Research2013，24，4： | 3 |
| 4 | Structure and regeneration status of woody species in the Munessa Forest,Southern Ethiopia显示文摘This study evaluates the structure and regeneration status of woody species in the Munessa Forest,a dry Afromontane forest in southern Ethiopia.Vegetation data were collected using a systematic sampling method.Density and distribution of seedlings,saplings and mature trees were assessed along an altitudinal gradient using quadrats of different sizes.The number of individuals,frequencies,heights and DBH of species>1 m and DBH>2.5 cm were recorded in altitudinal bands of 100 m.Analysis of the vegetation structure shows that the density of woody species decreases as DBH and height class increases.Basal area of stems with DBH>2.5 cm was 53.4 m^(2)ha^(−1).Population structure and regeneration patterns indicate a significant degradation of the forest due to anthropogenic disturbances.Regeneration was better for less valuable woody species than for species with economic and ecological value.This suggests a discontinuous recruitment of these species due to selective cutting of middle and higher diameter classes.Therefore,enrichment planting of high value,endangered species is necessary to maintain them as part of this forest.There is a need to develop and implement an effective forest management plan for sustainable use of these forest resources. | Mengistu Gelasso Junqing Li | 2021 | Journal of Forestry Research2021，32，2： | 0 |
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