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181.
徐州王庄煤矿山西组孢粉植物群及其地层意义   总被引:1,自引:0,他引:1  
徐州王庄煤矿山西组中、下部产有丰富的孢粉化石,保存完好,共计55属132种(包括3新种)2个未定型孢子及1个疑源类未定类型。根据孢粉属种组成及其含量的变化,自下而上分为两套组合:Cyclogranisporites-Gulisporites-Laevigatosporites-Florinites组合(简称组合1)和Calamospora-Gulisporites-Vesiculatisporites-Florinites组合(简称组合2)。根据组合内一些重要分子的地质时限讨论及其与相关组合的对比,将组合1的地质时代归为早二叠世早期,组合2的时代归为早二叠世晚期。文中描述孢子3新种,图示孢子花粉91种。  相似文献   
182.
本文首次报道了山西省五倍子资源现状及分布规律 ,讨论了影响山西省五倍子生产的关键因素及应采取的对策。  相似文献   
183.
浙江淡水维管束植物的区系特点与地理分布   总被引:17,自引:1,他引:16  
根据15年的调查结果,对浙江省水生维管束植物的区系与地理分布特点进行了研究。已知浙江有水生维管束植物150种,隶属于78属,42科。将78属归纳为11个分布区类型,以世界分布类型所占比例最高,热带分布属总数多于温带分布属,泛热带分布和北温带分布比例非常高。将150种植物归纳为13个分布区类型,温带分布远多于热带分布,以东亚分布类型最为突出,体现了中国-日本植物区系的明显特征,探讨了浙江水生植物的水平地带性和垂直地带性分布规律,其分布不仅与气候带有关,更与水生的生境的分布格局有关。最后,报浙江水生植物濒危种的受威胁状况。  相似文献   
184.
陕北黄土高原森林植被数量分类及环境解释   总被引:22,自引:0,他引:22  
相辉  岳明 《西北植物学报》2001,21(4):726-731
通过对陕北黄土高原森林群落的系统聚类分析和因子分析(FA)及其与5个土壤变量的多元统计分析。定量研究了该地区森林植被的类型及土壤特征之间的相互关系。结果表明,陕北黄土高原森林植被可分为5个群系,即油松林、辽东栎林、山杨林、白桦林和侧柏林,聚类分析结果与传统分类的结果完全一致。该地区森林植被格局可由群落土壤条件的差异来解释,土壤因子中含水量、全氮和有机质是主导性因素,各群落沿此梯度呈现出一定的分布格局,其它土壤因子的作用并不明显。  相似文献   
185.
《植物生态学报》2016,40(9):861
Aims Spatial distribution patterns and formation mechanisms of species diversity are fundamental issues in community ecology. The objectives of this study are to assess the species diversity patterns at the different spatial scales in Jianfengling, Hainan Island, China.
Methods Based on the dataset from the 60 hm2 plot in the tropical montane rain forest in Jianfengling, Hainan Island, the spatial distribution patterns of species richness, species abundance, Shannon-Wiener, Simpson and Pielou’s evenness indices were analyzed at six spatial scales, including 5 m × 5 m, 10 m × 10 m, 20 m × 20 m, 40 m × 40 m, 100 m × 100 m, and 200 m × 200 m, respectively.Important findings
Results showed that spatial distribution patterns of species richness, species abundance and Shannon-Wiener index were much more obviously changed with the spatial scales than Simpson and Pielou’s evenness indices. Change of variance of the species richness with the increase of spatial scales was unimodal, which had the maximum value at the 20 m × 20 m scale. Variance of the species abundance showed a linear relationship with the increase of spatial scales. The positive relationship between species richness and abundance gradually decreased and even disappeared with the increase of sampling scales, which may be correlated with the increase of habitat heterogeneity. The effects of spatial scales on Shannon-Wiener, Simpson, and Pielou’s evenness indices may be also correlated with the composition of rare species in the plot.  相似文献   
186.
Aims Modelling potential distribution ranges of threatened species is of great significance for their conservation. In this paper, the distribution of potential suitable habitat of Impatiens hainanensis, a limestone-endemic and endangered plant in Hainan Island, was studied to provide scientific basis for their effective in situ conservation and re-introduction of I. hainanensis. Methods Based on eight occurrence sites and 12 environmental variables, the Maximum Entropy (MaxEnt) algorithm and GIS technology were used to create a model linking the distribution ranges of I. hainanensis with environments. With data on five actual distribution sites and five non-occurrence sites, four model evaluation metrics (area under the receiver operating characteristic curve (AUC), kappa coefficient, true skill statistic (TSS), overall accuracy) were used to evaluate the predictive performance and accuracy of this model. Important findings The results indicated that the indicative value of all four evaluation metrics were above 0.9, indicating that the MaxEnt model can effectively predict the potential suitable habitats of I. hainanensis. Slope, precipitation of the driest quarter and coefficients of precipitation variation were the three main environmental factors influencing the distribution of I. hainanensis. At present, the most suitable habitat includes western and southern parts of Baisha County, the central and southern parts of Changjiang County, the eastern part of the Dongfang City and northeastern Ledong County, accounting for 1.8% of land area on Hainan Island. Since the potential suitable habitat of I. hainanensis is rare and severely fragmented, the protection of this species is urgent. We suggest to collect the seeds of various geographic populations of I. hainanensis to establish a germplasm resource bank. The most suitable habitat of the species, including Tian’an Village and Jiangbian Village in Dongfang City, northeast of Ledong County (Jiaxi Reserve), should be selected as the priority places for future extensive field surveys and re-introduction. © Chinese Journal of Plant Ecology.  相似文献   
187.
Aims Our objective was to estimate the carbon storage in the forest tree layer in Qinghai Province, China. Methods Based on forest resource inventory data and field investigation data, we estimated the carbon storage, sequestration rate and potentials in the forest tree layer in the Qinghai Province. Important findings The carbon density and total carbon storage of forest tree layer in Qinghai Province was 76.54 Mg·hm-2 and 27.38 Tg, respectively, of which four forest types (Picea spp. forest, Cupressus funebris forest, Betula spp. forest and Populus spp. forest) accounted for 86.67% while their areas were 96.23% of total forest areas in Qinghai. The carbon density and carbon storage of Picea spp. forest was 106.93 Mg·hm-2 and 14.78 Tg, respectively, which was the largest among all forest types. The carbon storage of the forest tree layer at different stand ages followed the sequence of over-mature forest > middle-aged forest > mature forest > near-mature forest > young forest. In addition, the carbon storage of forest tree layer in the province increased from 23.30 Tg in 2003 to 27.38 Tg in 2011. The average annual growth of carbon and carbon sequestration rate were 0.51 Tg and 1.06 Mg·hm-2·a-1, respectively. The maximum and minimum of carbon sequestration rate were respectively found in Cupressus funebris forest (0.44 Mg·hm-2·a-1) and Betula spp. forest (-1.06 Mg·hm-2·a-1). The mean carbon sequestration potential reached 8.50 Tg in 2011, with the highest value found in Picea spp. forest (3.40 Tg). These findings suggested high carbon sequestration potential of forest tree layer in Qinghai Province. Therefore, the carbon storage in Qinghai Province could be increased through better forest management and utilization. © 2018 Editorial Office of Chinese Journal of Plant Ecology. All rights reserved.  相似文献   
188.
2017年5月分别在贵州省兴义市和安龙县用雾网采集到1只大体型雌性管鼻蝠和2只小体型雄性菊头蝠,经鉴定为毛翼管鼻蝠(Harpiocephalus harpia)和华南菊头蝠(Rhinolophus huananus),属贵州省翼手目新分布记录。所采集的毛翼管鼻蝠雌性个体可能为怀孕个体,故测量相关数据并鉴定后原地放归野外。华南菊头蝠标本保存于东北师范大学环境学院。毛翼管鼻蝠(1♀):鼻部呈短管状,全身被毛厚密而柔软,后足、翼膜和尾膜均被覆黄褐色绒毛;体重14.01 g,前臂长48.23 mm;回声定位声波为调频(FM)型,静止状态下声波峰频为(56.04±4.52)k Hz。华南菊头蝠(2♂):耳大,对耳屏相对较小;鼻叶之蹄状叶宽大,完全覆盖吻部;鞍状叶小,其高略超过其宽,近乎矩形;体毛烟褐色;2只样本体重分别为4.52 g、4.12 g,前臂长40.70 mm、40.00 mm;头骨狭长,颅全长16.35 mm、16.46 mm,颅宽8.11 mm、8.14 mm;回声定位声波属调频-恒频-调频(FM-CF-FM)型,静止状态下峰频分别为(68.48±0.08)k Hz、(67.18±0.06)k Hz。2种蝙蝠物种在贵州省为首次发现,扩大了其在国内的分布范围,丰富了生态资料,为进一步的研究和保护提供了基础资料。  相似文献   
189.
周氏啮小蜂(海南种群)对椰子织蛾的寄生功能反应   总被引:1,自引:0,他引:1  
【目的】周氏啮小蜂(海南种群)是寄生椰子织蛾蛹期的本土天敌。研究周氏啮小蜂(海南种群)对椰子织蛾的功能反应,能为该蜂室内扩繁和室外控害利用提供基础。【方法】在室内观察周氏啮小蜂(海南种群)寄生行为基础上,研究了营养(10%蜂蜜)、寄主蛹(初、中、晚)期对周氏啮小蜂(海南种群)寄生功能反应的影响。【结果】镜下观察1头周氏啮小蜂(海南种群)可寄生多头椰子织蛾蛹,寄生量随寄主密度的增大而增加,但当寄主密度达到一定程度后,其增长率随寄主密度的增大逐渐减缓,属于HollingⅡ功能反应。在无营养条件下,周氏啮小蜂(海南种群)对椰子织蛾初、中、晚期蛹的理论最大寄生量分别为1.5、1.4、1.2头·d~(-1);在10%蜂蜜饲喂条件下,周氏啮小蜂(海南种群)对椰子织蛾初、中、晚期蛹的理论最大寄生量分别为1.8、1.7、1.3头·d~(-1)。【结论】HollingⅡ型拟合结果表明,椰子织蛾初期蛹是周氏啮小蜂(海南种群)寄生的最佳时期,补充营养能够提高椰子织蛾的寄生力。  相似文献   
190.
【目的】云南是外来入侵生物的重灾区,了解外来有害生物入侵现状、加强防控尤为紧迫。【方法】从入侵云南外来有害生物类别、入侵途径、造成的损失等方面对云南省外来有害生物的入侵现状进行了阐述,对云南口岸疫情进行统计分析。【结果】按进境检疫物上截获有害生物批次及疫情货物批次统计的国家主要为缅甸、老挝、泰国、越南、荷兰5个国家;按检疫方式分类统计,货检截获批次最多,旅检次之,二者之和占总截获批次的99%;按有害生物类别分类统计,昆虫截获最多,占总截获批次的70.0%至73.9%,杂草、真菌居次,细菌、线虫、病毒、螨类、其他又次之;按货物类别统计,截获有害生物批次最多为粮豆类,占总截获批次的46%。【结论】提出了相应的检疫监管对策与建议,以期为口岸检疫提供参考,降低外来有害生物的入侵风险。  相似文献   
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