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1.
The present study was undertaken in moist temperate forest of Mandal-Chopta area in the Garhwal region of Uttarakhand, India. The aim of the present study was to understand the regeneration dynamics of the dominant tree species along an altitudinal gradient in naturally regenerating, restricted access forest. The overall regeneration status was fairly high in the study area. Most of the native canopy and undercanopy dominants had frequent reproduction and expanding populations, which suggests the stability of forest structure/composition and further expansion of dominant species. The overall regeneration of trees in the forest had a greater contribution of middle and understorey species. Because of infrequent reproduction and declining populations of some of the dominant native species viz., Abies pindrow, Alnus nepalensis and Betula alnoides, structural/compositional changes in the future are expected in respective forests dominated by them. Abies pindrow and Taxus baccata need immediate attention by forest managers for their survival in the area. Seedlings were found to be more prone to competition from herb and shrubs than saplings.  相似文献   

2.
为揭示喜马拉雅山蚂蚁群落的生态学规律,采用样地调查法对喜马拉雅山底雅段和札达段的蚂蚁群落进行调查。共观察蚂蚁5355头,隶属于2亚科5属7种,其中底雅段7种,札达段3种。对该地区蚂蚁物种丰富度进行估计,结果表明底雅段和札达段的蚂蚁物种丰富度较低。底雅段南坡的蚂蚁物种数目、Shannon-Wiener多样性指数、Fisherα指数和优势度指数表现出"中域效应"现象,而个体密度则表现出"多域效应"现象;札达段南坡的蚂蚁物种数目、个体密度和Fisherα指数均表现出"多域效应"现象。蚂蚁群落相似性系数显示各样地间的蚂蚁群落处于极不相似至极相似水平,表明该地区不同海拔蚂蚁群落既有差异又存在一定共性。在底雅段和札达段,海拔对蚂蚁物种的分布和多样性有较大影响,坡向和植被对蚂蚁群落分化有重要作用。  相似文献   

3.
In this study, we investigated the specific gravity of wood samples collected from a total of 31 woody species, consisting of 20 trees, 10 shrubs and one species of bamboo from sub-tropical regions of Garhwal Himalayas, India. Results show that among these woody species, the specific gravity of trees ranged from 0.34 for Erythrina suberosa to 0.83 for Albizia procera. For shrub species the specific gravity of Ricinus communis was 0.39 and that of Dodonaea viscosa 0.93. The average specific gravity of trees was 0.58 and of shrubs 0.66.  相似文献   

4.
Four forest stands each of twenty major forest types in sub-tropical to temperate zones (350 m asl–3100 m asl) of Garhwal Himalaya were studied. The aim of the study was to assess the stem density, tree diversity, biomass and carbon stocks in these forests and make recommendations for forest management based on priorities for biodiversity protection and carbon sequestration. Stem density ranged between 295 and 850 N ha−1, while total biomass ranged from 129 to 533 Mg ha−1. Total carbon storage ranged between 59 and 245 Mg ha−1. The range of Shannon–Wiener diversity index was between 0.28 and 1.75. Most of the conifer-dominated forest types had higher carbon storage than broadleaf-dominated forest types. Protecting conifer-dominated stands, especially those dominated by Abies pindrow and Cedrus deodara, would have the largest impact, per unit area, on reducing carbon emissions from deforestation.  相似文献   

5.
Agroforestry systems, though at subsistence level are well established in Garhwal Himalayas. The farmers undertake cultivation of various crops, seasonal and biennials crops with trees all in mixtures on the same piece of land. Farm animals and poultry form an essential component of the systems. The intimate association of different species provides both subsistence and commercial products which give additional income to the farmer. The paper describes the general scenario of socio-economic condition and existing agroforestry practices and some suggestions for their improvement in the Garhwal Himalayas.  相似文献   

6.
From March 2007 to March 2009 we quantified plant diversity at Chilapatta Reserve Forest in Terai Duars in the Indian eastern Himala-yas. We sampled stratified random nested quadrats. Species richness was 311, representing 167 genera and 81 families. The species diversity index and concentration of dominance of the forest were 2.20 and 0.0072, respectively. Shannon-Wiener index and evenness indices were 4.77 and 1.44, respectively. The Importance Value Index (IVI) of species ranged from 0.13 to 37.94. The estimated diversity indices indicated heterogene-ity of the forest in its composition, structure, function and dynamics. Rich forest plant diversity supports the need for continued conservation of tropical forests.  相似文献   

7.
薛煜  包立新  李淳 《林业研究》1996,7(3):19-22
INTRODUCTIoNSSPCCiesdiversityistheoneofthreekcysubjcctS(Theglobalweatherchange,speiesdiversltyandsustainedecologysystem)inccologicalandenvironmentalscienceinrecenttenyears.Williams(I943)firstputfonvardsPecicsdiversitywhenhestUdiedtherelationbctx`centhcabundanccandinsectspecicsofLcl,i`mptcra.In6()'s~7()'s-ccologicaIscicn-tistshadgotagreatofachicvementsonsPCcicsdlt'crslti'stud\.Sinccl98()-s.somcscientistsstartcdtostud}'sPCcicsdivcrsityinCl1ina.Thcy'havcgotsolnercsultsol1artl1roPOdcom…  相似文献   

8.
Tree species diversity and population structure at different community types were described and analyzed for primary and secondary lowland moist deciduous forests in Tripura.Overall 10,957 individual trees belonging to 46 family,103 genera and 144 species were counted at ≥30 cm DBH(diameter at breast height) using 28 permanent belt transects with a size of 1 ha(10 m × 1000 m).Four different tree communities were identified.The primary forests was dominated by Shorea robusta(mean density 464.77 trees ha-1,105 species) and Schima wallichii(336.25 trees ha-1,82 species),while the secondary forests was dominated by Tectona grandis(333.88 trees ha-1,105 species) and Hevea brasiliensis(299.67 trees ha-1,82 species).Overall mean basal area in this study was 18.01m 2 ·ha-1 ;the maximum value was recorded in primary Shorea forest(26.21 m 2 ·ha-1).Mean density and diversity indices were differed significantly within four different communities.No significant differences were observed in number of species,genera,family and tree basal cover area.Significant relationships were found between the species richness and different tree population groups across the communities.Results revealed that species diversity and density were increased in those forests due to past disturbances which resulted in slow accumulation of native oligarchic small tree species.Seventeen species were recorded with <2 individuals of which Saraca asoka(Roxb.) de Wilde and Entada phaseoloides(L.) Merr.etc.extensively used in local ethno-medicinal formulations.The present S.robusta Gaertn dominated forest was recorded richer(105 species) than other reported studies.Moraceae was found more speciose family instead of Papilionaceae and Euphorbiaceae than other Indian moist deciduous forests.Seasonal phenological gap in such moist deciduous forests influenced the population of Trachypithecus pileatus and capped langur.The analysis of FIV suggested a slow trend of shifting the population of Lamiaceae group by Moraceae species in secondary T.grandis L.dominated community.  相似文献   

9.
赣西油茶人工林土壤微生物群落的多样性   总被引:1,自引:0,他引:1  
为了解油茶林土壤微生物群落结构特征,揭示油茶林土壤微生物群落结构多样性变化特征对林龄和季节等环境因素的响应机制,为油茶林合理经营管理提供理论依据,以赣西地区新余市渝水区不同林龄油茶林24个土壤样品为研究对象,采用变性梯度凝胶电泳(PCR-DGGE)技术分析油茶林土壤细菌群落多样性。DGGE指纹图谱分析结果表明,油茶林土壤微生物类群的细菌多样性较丰富,各个样品的条带数目稳定分布在13~36条。10年龄油茶人工林细菌基因多样性较为丰富,集约经营10年龄油茶林的细菌物种数量多。细菌丰富度和Shannon-Wiener多样性指数在林龄变化上均表现为中龄林(2个10年龄)成熟林(30年龄、50年龄)幼龄林(1年龄、6年龄);其在季节变化上均呈一致的变化规律,为夏季秋、冬季春季。细菌16S rDNA的系统发育分析结果表明,大多数序列与未培养细菌的同源性较高,所有序列与数据库中16S rDNA序列的相似性在84%~99%。遗传关系研究得到主要的优势菌为泛菌属Pantoea sp.、肠杆菌属Enterobacter sp.。  相似文献   

10.
不同森林类型物种多样性及影响因子研究   总被引:2,自引:0,他引:2  
采用丰富度指数、多样性指数、均匀度指数对雾灵山不同森林类型灌木层和草本层的物种多样性进行了研究,并在此基础上用逐步回归方法研究影响森林物种多样性的主要因子。结果表明,在不同森林类型中灌木层和草本层物种多样性由高到低依次为:针阔混交林>落叶阔叶林>针叶林;多数森林类型草本层丰富度指数和多样性指数均高于灌木层,而均匀度指数则相反。影响灌木层物种多样性的主要因子包括林龄、郁闭度和坡向,影响草本层物种多样性的主要因子包括林分公顷株数、郁闭度和土层厚度。  相似文献   

11.
Accurate estimates of tree carbon,forest floor carbon and organic carbon in forest soils (SOC) are important in order to determine their contribution to global carbon (C) stocks.However,information about these carbon stocks is lacking.Some studies have investigated regional and continental scale patterns of carbon stocks in forest ecosystems;however,the changes in C storage in different components (vegetation,forest floor and soil) as a function of elevation in forest ecosystems remain poorly understood.In this study,we estimate C stocks of vegetation,forest floor and soils of a Pinus roxburghii Sargent forest in the Garhwal Himalayas along a gradient to quantify changes in carbon stock due to differences in elevation at three sites.The biomass of the vegetation changes drastically with increasing elevation among the three sites.The above-ground biomass (AGB) and below-ground biomass (BGB) were highest at site Ⅰ (184.46 and 46.386 t·ha-1 respectively) at an elevation of 1300 m followed by siteⅡ (173.99 and 44.057 t·ha-1 AGB and BGB respectively) at 1400 m and the lowest AGB and BGB were estimated at site Ⅲ(161.72 and 41.301 t·ha-1) at 1500 m.The trend for SOC stock was similar to that of biomass.Our results suggest that carbon storage (in both soil and biomass) is negatively correlated with elevation.  相似文献   

12.
We documented the status of fern diversity,biomass and carbon accumulation at Chilapatta Reserve Forest in Cooch Behar Wildlife Division,West Bengal.Stratified random nested quadrat sampling was adopted for analyzing the qualitative and quantitative characters.Nineteen fern species were recorded,of which two are yet to be identified.Identified species were of eight families and nine genera.Highest and lowest frequency recorded were 25.44 and 0.19 while relative frequency varied from 3.16 to 12.25.Fern density ranged from 93 to 13,403 individuals·ha-1.Most of the species were widely distributed.IVI values ranged from 7.54 to 37.45.The above ground portion of ferns accumulated the major portion of biomass and carbon.  相似文献   

13.
在喜玛拉雅嘎瓦耳(Garhwal Himalaya)地区,选择7种温带(1500 to 3100 m,a.s.l.)森林类型,研究不同坡面(东北,西北,东南,西南)对自然森林的森林成分、群落结构和土壤特性的影响。在每种森林中自由采样。为了阐明研究不同坡面(东北、西北、东南、西南)对天然森林的森林成分、群落结构和土壤特性的影响,利用标准统计软件计算多种指标,如,重要价值指标、Shannon-Wiener多样性指数、优势辛普森浓度、辛普森多样性指数、种均匀度和物种丰富度指数。在每种森林中采集复合土壤样品,分析土壤的物理化学特性、水分含量、持水量、pH、有机碳、磷、钾和有效氮含量。结果表明,北坡森林的总基盖度(高山栎林Quercus semecarpifolia为74.4 m2&#183;ha-1)、优势度(长叶松林Pinus roxburghii为0.85)和树种多样(石斛蟹Quercus floribunda为1.81)均高于其他坡位森林,北坡森林土壤中的水分含量(白橡树Quercusleucotrichophora为40.8%)、持水量(藏柏Cupressus torulos为48.9%)、有机碳(雪松Cedrus deodara为3.8%)、磷(白橡树Quercus leucotrichophora为31.9 kg&#183;ha-1)和氮(西藏长叶松林Pinus roxburghii为1.0%)均比其他坡位土壤值高。因此,北坡森林的生产力较高。  相似文献   

14.
湘中丘陵区3种林分林下植物多样性与土壤特性研究   总被引:1,自引:0,他引:1  
在湘中丘陵区选取针叶林、针阔混交林和阔叶林为研究对象,研究三种林分林下植被多样性、土壤理化性质及其相关关系。结果表明:三种林分林下植物多样性总体表现为灌木层明显高于草本层,阔叶林、针阔混交林高于针叶林。土壤有机质、全N和全P含量基本表现为随土层加深而下降的规律。土壤含水率与各项多样性指标不相关,土壤容重、p H值与灌草层各多样性指数呈负相关关系,有机质、全N与灌木层均匀度指数呈负相关关系,有机质与草本层均匀度指数呈极显著正相关关系(P0.01),全P、全K与灌木层多样性指数呈显著正相关关系(P0.05)。  相似文献   

15.
广州市森林群落特征与物种多样性研究   总被引:2,自引:0,他引:2  
广州市的天然次生林,其植物种类丰富,主要的植被类型有常绿季雨林、常绿阔叶林、针阔混交林和常绿灌丛,其地带性植被为南亚热带季风常绿阔叶林;植被组成种类丰富,具有较强的热带性,主要的科有豆科、茜草科、大戟科、樟科、桑科、山茶科、壳斗科、紫金牛科、芸香科、金缕梅科、冬青科等一些以热带亚热带为分布中心的类群;根据实地调查和收集的有关资料统计,目前一些珍稀濒危植物几乎都分布在森林公园内得以很好的保护;建议将兰花40种和另外52种植物列为广州市重点保护植物。    相似文献   

16.
More than 300 wild edible mushrooms are consumed in Mexico. They have been reported mainly from temperate forests in the center and southeast of the country. However, these valuable non-timber forest products are under-utilized because a lack of knowledge on their ecology and productivity. The objectives of this work were to compare the richness and fruit body production of wild edible mushrooms in temperate forests with a distinct vegetation composition in Amanalco, to describe species availability, and to test a new sampling approach in a heterogeneous environmental context. We designed a sampling method with random transects rather than traditional fixed sampling sites. Our method permits the acquisition of data from the highest number of environmental conditions. In 2009 and 2010, we collected and counted mushrooms in 248 transects distributed in five vegetation types (Abies, AbiesPinus, Pinus, PinusQuercus and Quercus). We calculated the ecological importance value of each species as a function of its relative abundance and relative spatial frequency and relative temporal frequency. Abies religiosa pure stands and A. religiosaPinus forests had the greatest richness of edible fungi (43.1 and 21.3 species ha?1, respectively) and produced most of the fruit bodies (1,160 and 820 ha?1, respectively). The most abundant species in Amanalco region (combining all the vegetation types), Clavulina cinerea, Clitocybe gibba and Russula brevipes, also had the highest ecological importance value (0.2312, 0.1709 and 0.1516, respectively). These temperate forests maintain a considerable diversity of valuable wild edible mushrooms that are heterogeneously distributed according to the type of vegetation.  相似文献   

17.
Three Pinus tabulaeformis populations which experienced tending, shelterwood cutting, and closed tending were separately investigated to study the effects of these three forest practices on the age structures, static life tables, survivorship curves, and species diversities of P. tabulaeformis populations in Huanglongshan Mountain. Time sequence model was adopted to predict the dynamic population numbers of different P. tabulaeformis populations with different forest practices. The results revealed that the three populations are essentially identical in population structure, their young and old individuals make up a small proportion and their mid-aged individuals make up a large proportion and consequentially P. tabulaeformis populations generally stand stable. In the P. tabulaeformis communities with three tending practices, the highest species abundance index appears with tending and shelterwood cutting and the highest evenness index and species diversity appears with closed tending. The P. tabulaeformis populations with tending and shelterwood cutting practices belong to one developmental type and the P. tabulaeformis populations with closed tending practices belong to a stable type. It indicated that in the future, closed tending as the major practice and tending and shelterwood cutting as the supporting practices should be applied for P. tabulaeformis populations in Huanglongshan Mountain so that the communities will develop continuously. __________ Translated from Acta Botanica Boreali-Occidentalia Sinica, 2006, 26(5): 1,007–1,013 [译自: 西北植物学报]  相似文献   

18.
通过对石家庄山区石包垴核桃楸林中调查所涉及到的27种植物的数量特征进行分析,发现核桃楸、细叶苔草、全叶紫堇等植物的重要值较高,在群落中占据明显优势。运用物种丰富度指数(S)、Shannon-Wie-ner多样性指数(H)、Sinpson多样性指数(D)、Pielou均匀度指数(Jsw、Jsi)指标,研究了该区的物种多样性,结果表明:丰富度指数和多样性指数均表现为:草本层>乔灌层,均匀度指数表现为:乔灌层(Jsw)>草本层(Jsw)。研究中对天然林和人工林物种多样性进行了比较,结果为草本层:天然林>人工林,乔灌层:人工林>天然林,总体多样性指数为:天然林>人工林。瑙基耶尔(Raunkiaer,1934)生活型谱分析结果为:地面芽植物为44.44%,占居优势地位,隐芽植物次之,为33.33%,高位芽植物和1年生草本植物较少,无地上芽植物。  相似文献   

19.
以金洞林场杉木纯林、杉木-闽楠混交林为研究对象,对不同密度和混交比例的林分进行研究,将物种多样性指数作为衡量林分密度和混交比例是否合理的参考指标,为人工混交林的经营提供理论依据。采用典型抽样法,按其混交比例分为类型Ⅰ(10杉)、类型Ⅱ(9杉1楠)、类型Ⅲ(7杉3楠)、类型Ⅳ(5杉5楠)4种类型设置典型样地,同种类型林分设置3个密度等级,低密度(A:600~1000株/hm^2)、中密度(B:1200~1600株/hm^2)、高密度(C:2000~2400株/hm^2),对比分析其林下植被物种组成及多样性差异。结果表明:从类型Ⅰ至类型Ⅳ随着闽楠比例的增加其林下植被的物种数增加。林下灌木及草本Patrick丰富度指数、Shannon-Wiener多样性指数、Simpson优势度指数表现为类型Ⅳ>类型Ⅲ>类型Ⅱ>类型Ⅰ。林分密度及混交比例与林下灌木及草本层的物种多样性指数呈显著(P<0.05)或极显著相关关系(P<0.01);拟合曲线表明林下植被Shannon-Wiener多样性指数和Patrick丰富度指数达峰值时的闽楠比例为0.465~0.506,即闽楠比例在46.5%~50.6%之间其林下植被物种多样性达到最大值。物种多样性指数与密度及混交比例均具有显著或极显著相关关系,可将物种多样性作为确定杉木-闽楠混交林最适密度和混交比例的因子之一。当前阶段,金洞林场杉木-闽楠混交林最适密度为1200~1600株/hm^2,杉木与闽楠的株数比例控制在0.97~1.10之间。  相似文献   

20.
辽西地区水土保持林主要林分类型及结构特征分析   总被引:1,自引:0,他引:1  
对辽西地区现有几种主要的水土保持林分类型进行了结构特征分析,结果表明,混交类型的水土保持林,其林分层次结构、生长情况均好于油松纯林,物种我样性指数高于纯林;林分生物量以油松-刺槐形成的乔木混交林最高,达96.550t/hm^2,比油松纯林提高57.658t/hm^2;各类型混交林林地土壤理化性质有了很大的改善,混交类型林地土壤容重比纯林减小0.05-0.2g/cm^3、孔隙度提高0.76%-3.45%、有机质提高0.03%-0.73%、全氮含量提高0.004%-0.036%,说明油松阔叶混交林在改善土壤理化性质方面起了重要作用;林分枯枝落叶量及持水量也明显高于油松纯林,油松-刺槐形成的乔木混交林是辽西地区林分结构较为理想的混交类型。  相似文献   

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