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1.
The infill of abandoned river channels is the main information source on postglacial vegetation and landscape evolution in inland northern Belgium. Palynological studies of these deposits also contribute to a better understanding of the environmental context of the numerous archaeological sites in this area. The results are presented of palynological analyses, including pollen, spores, non-pollen palynomorphs and microcharcoal from the palaeochannel infill at seven sites in the Scheldt and Durme valleys in northern Belgium. Based on the regional vegetation evolution and radiocarbon dating, a biozonation for the Scheldt Basin is constructed encompassing the final Late-glacial and Holocene period. The local taxa show a hydroseral succession from open-water environment, through reed or sedge fen to carr forest. Salix and Viburnum opulus were important elements in the Early Holocene riparian and carr vegetation, but are often underrepresented in pollen diagrams from larger valleys. There are indications for human disturbance and agriculture between 7,000 and 6,400 cal bp. The simultaneous decline of elm and lime in the study area around 4,000 cal bp can be linked to human impact.  相似文献   

2.
The results of anthropological research into human evolution have been discussed. Only two research places in CSSR have been engaged with the human evolution: the Department Anthropos in the Moravian Museum in Brno and the Laboratory of Evolutionary Biology of the Czechoslovak Academy of Sciences in Praha. The first of them has been mainly concerned with the paleontological and archeological research reported elsewhere. In the second, the following main questions of human evolution have been discussed: the evolution of bipedal locomotion, the morphological aspects, both qualitative and quantitative ones, the locomotion in other primates and various aspects of their behaviour have been studied. In this connection also various questions of the evolution the of human mind and social consciousness were studied. Special attention has been paid to role of neoteny in the evolution of man and to the import of synergism of the main evolutionary factors. As one of the main results is the principle of sociogenesis viewed and its various aspects. Its top product is human consciousness integrating the most important results of human thinking. Much attention has been paid to its evolution on the basis of the principle of reflection. Also the philosophical and ideological consequences of the sociogenesis as the main trend in the evolution of organisms have been elaborated in detail.  相似文献   

3.
Four profiles were sampled from three mires situated near the town of Světlá nad Sázvou in the western forland of the Bohemian-Moravian Uplands. The sites were studied pollen analytically. In one of the profiles macroscopic analyses were also carried out. The aim of the analyses performed was to provide data for reconstructing the vegetational evolution in the area under study. A survey of vegetation changes from the Late Glacial (Alleröd) up to the present was obtained. Special attention was devoted to the composition of original forest stands and to their changes due to the impact of man. The results were compared with the conclusions of the geobotanical reconstruction mapping, of forest-type mapping, of the biogeographical mapping, and of archives of forest records.  相似文献   

4.
气候,地形,植被与西部环境重建   总被引:3,自引:1,他引:2  
植被是生态环境的标志,植被类型与气候和地形条件关系密切,重建西部生态环境,依据自然规律,因地制宜,做出长远规划,否则,将会事倍功半。  相似文献   

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The objective of our work was to verify the value of the vegetation corridor in the conservation of small mammals in fragmented tropical landscapes, using a model system in the southeastern Minas Gerais. We evaluated and compared the composition and structure of small mammals in a vegetation corridor, forest fragments and a coffee matrix. A total of 15 species were recorded, and the highest species richness was observed in the vegetation corridor (13 species), followed by the forest fragments (10) and the coffee matrix (6). The absolute abundance was similar between the vegetation corridor and fragments (F = 22.94; p = 0.064), and the greatest differences occurred between the vegetation corridor and the matrix (F = 22.94; p = 0.001) and the forest fragments and the matrix (F = 22.94; p = 0.007). Six species showed significant habitat preference possibly related to the sensitivity of the species to the forest disturbance. Marmosops incanus was the species most sensitive to disturbance; Akodon montensis, Cerradomys subflavus, Gracilinanus microtarsus and Rhipidomys sp. displayed little sensitivity to disturbance, with a high relative abundance in the vegetation corridor. Calomys sp. was the species least affected by habitat disturbance, displaying a high relative abundance in the coffee matrix. Although the vegetation corridors are narrow (4 m width), our results support the hypothesis in which they work as a forest extension, share most species with the forest fragment and support species richness and abundance closer to forest fragments than to the coffee matrix. Our work highlights the importance and cost-effectiveness of these corridors to biodiversity management in the fragmented Atlantic Forest landscapes and at the regional level.  相似文献   

7.
廖梦娜  谭斌  倪健  李凯 《生态学报》2019,39(21):8027-8037
立地尺度植被定量重建是对利用孢粉进行古气候和古环境研究的一个重要补充。一些新的定量重建模型相继提出,但其适用性仍需进一步验证。以柴达木盆地24个样方表土孢粉及4个湖泊表层沉积孢粉为研究对象,利用MARCO POLO模型重建立地尺度植被盖度并分析该模型的适用性。研究结果表明,由于地形开阔且风力较大,干旱区的大型湖泊沉积物中往往容易富集超代表性孢粉,使这些孢粉的区域信号增强,从而降低孢粉类型筛选的正确率。若湖泊与样方间的距离较近,湖泊表层孢粉能够更好地反映样方所在区域的孢粉特征,则有利于提高孢粉类型筛选的正确率。MARCO POLO模型中的孢粉代表性R值是将孢粉含量转化为植被盖度的关键参数。由于受到孢粉自身生产、传播、保存以及外部环境等多方面因素的影响,不同样方的R值可能差异很大。因此在运行该模型前需保证R值能够准确反映立地尺度中各孢粉类型与植被盖度的关系。仅在以柴达木盆地为代表的干旱区对该模型进行检验,今后仍需要在不同植被或气候区进行深入研究以全面了解该模型的适用条件。  相似文献   

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系统研究了南方5个亚热带森林生态系统地表植被的动态变化情况.研究方法是:在每个研究区域内,按照地形梯度分别布设50个1m2 的样方,记录样方内所有物种的频度及相关的环境变量,5个研究区域共设250个样方,每个样方分别调查两次.通过单元及多元统计方法分析表明:维管植物物种频度在一个区域明显下降,另二个区域显著增加;苔藓物种频度在一个区域有明显下降,另一个区域明显增加;苔藓物种数量在3个区域显著增加,另二个区域显著下降;维管植物物种数量显著增加在二个区域;物种组成沿着第一个植被梯度轴DCA 1没有显著变化,沿着第二个植被梯度轴DCA 2在二个区域有显著变化.综合分析表明,苔藓对气候变化及其波动反映敏感,是较好的气候变化及气候波动生物指示因子,而管植物数量及频度的变化没有明显证据显示与土壤酸化和大气污染有紧密关系.  相似文献   

10.
汉江上游金水河流域森林植被对水环境的影响   总被引:3,自引:0,他引:3  
卜红梅  党海山  张全发 《生态学报》2010,30(5):1341-1348
以汉江上游金水河流域为研究区域,分析了流域森林植被对水环境的影响。利用年降水量、林冠截留率和不同森林类型面积的数据,计算了金水河流域森林生态系统的水源涵养量,分析了流域森林植被对水量的影响;采用监测的方法,分别对金水河流域阔叶林森林生态系统的大气降水、枯落物层、土壤层和出口河水的水质进行了比较分析,探讨流域森林植被对水质的影响。结果表明,(1)金水河流域森林生态系统的水源年涵养总量为466.79×106m3,(2)流域阔叶林森林生态系统能够调节pH值,缓解大气降水的酸性环境;降低了大气降水中TDS、CODMn、HCO3、SO4、Cl、NO3、NH4-N、NO3-N、PO4-P、TDP、As、Ba、Cr、Na、Pb、Fe、K、Mn、V和Zn的含量,净化了水质。(3)根据各贮水层的水质分析,推断了河水中各物质的不同来源。研究为南水北调中线工程水源地的管理和建设提供了参考。  相似文献   

11.
森林植被与大气颗粒物的关系   总被引:4,自引:0,他引:4       下载免费PDF全文
近年来,大气颗粒物成为我国城市大气的主要污染物,其中细颗粒物(PM2.5)粒径小、沉降困难,对环境的危害已成为亟待解决的问题。森林植被可显著消减空气颗粒物,有效改善空气环境质量。本文概述了植被对颗粒物的移除过程和方法,探讨了大气颗粒物与森林植被的相互关系。从单叶、单木及群落3个尺度,结合气象因素讨论了植被对移除大气颗粒物的影响,分析了颗粒物的后续再悬浮过程及对植被的危害。最后,从植被吸附颗粒物的能力测定和评价、本土高吸附PM2.5能力植被的筛选及综合研究不同植被配置结构的吸附效应等方面提出了植被吸附颗粒污染物,尤其是细颗粒物的研究重点与趋势。  相似文献   

12.
Abstract. Compositional gradients of forest vegetation in Finland were determined using detrended correspondence analysis, and ecologically interpreted with regression analysis. The data were collected in association with the 8th National Forest Inventory, and they comprised 1514 samples and 472 species, covering the whole forested land area of Finland. In the ordination space the first, very stable axis (DCA1) was much stronger than the following three, more unstable axes (DCA2 - 4). Site fertility (reflected by the forest site type series) and latitude had strongest covariation with the ordination space, followed by a number of variables primarily related to forest age or tree stand volume. Fertility variables were most closely parallel with DCA1, latitudinal ones with DCA1 and DCA2, and successional variables with DCA3. The results indicate that compositional overlap of sites classified into different Caj ander site types is considerable.  相似文献   

13.
A 10 year study of forest communities on Silhouette island, Seychelles demonstrates stability of forest composition in most areas over this time-scale. Areas with heavy invasion by alien species were found to be regenerating, particularly with the rapid loss of Clidemia hirta. This is attributed to the abundance of well-adapted native plants allowing competitive exclusion to take place, throughout competition for light. It was noted that invasive plant species tend to be unstable on the rocky slopes covered by native high forest. A high rate of tree fall and limited seed dispersal may reduce the impact of the invasive tree Paraserianthes falcataria in the future. Other species such as Cinnamomum verum and Psidium cattleianum may persist as major invaders due to wider seed dispersal.  相似文献   

14.
The study was carried out in two sample plots which were set in two regions where the vegetation was protected for 8 and 3 years.The results of DCA (Detrended Correspondence Analysis) showed that the vegetation on the north or northwest aspects in Yunmeng Mountain (Quercus liaotungensis coppice and Spiraea trilobata scrubs) has no systematic floristic difference from the vegetation which existed in the same area in 1964 with the approximate aspect under human disturbance, no matter whether they were protected for 8 or 3 years. In south and southeast slopes (Vitex negundo var. heterophylla community), the protected shrublands have larger species diversities than that of the shrublands in 1964. In addition, there is no significant difference between the communities which were protected for different periods of time. However, the number of species in protected area is larger than that in unprotected area. Furthermore, the community which is under a longer period of protection developes larger diversity. The north slopes have more species than the south slopes.The protection is helpful for communities to develope their biomass. The biomass of scrubs on the north slope is much greater than that on the south in the site where the vegetation is protected for 8 years, as well as in the site under 3 years protection. In contrast, due to the larger coverage of the scrubs on north slopes, the biomass of herbage on the south slope is much greater than that on the north slope in both sites. When compared with the biomass of the shrublands in unprotected area, the increase of biomass shows the efficiency of protection. The aboveground biomass of scrubs in both site are 2.8 and 2.2 times greater than that in unprotected area. The ratio of the total aboveground biomass of Site 1, Site 2 and the unprotected area is 2.5:2.2:1 on south aspect.  相似文献   

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A simulated map of the potential natural forest vegetation of Switzerland   总被引:1,自引:0,他引:1  
Using empirical data (ca. 7500 phytosociological releves), a simple, probabilistic ‘vegetation-site’ model was developed, to simulate geographical distribution of 71 forest community types, representing the potential natural vegetation (PNV) of Switzerland. The model was interfaced to a geographic information system (GIS) and used to generate a numerical vegetation map, on the basis of digital maps of 12 environmental variables including climatic conditions (temperature and precipitation), topography (elevation, slope, aspect), and soil parameters (soil pH and physical soil parameters). The predicted distribution of forest communities was compared with several vegetation maps, prepared for some subregions of Switzerland by means of traditional field methods. Similarity ranged from 50 to 80 %, depending on the community type, level of vegetational hierarchy and the geographical region. The current resolution and accuracy of the simulated vegetation map allows us to study the vegetational patterns on the level of the entire country or its major geographical and climatic regions. The simulated vegetation map is potentially an important tool in ecological risk assessment studies concerning the possible impacts of climate change on the ecological potential of forest sites and biological diversity of forest communities.  相似文献   

17.
云南热带森林植被分类纲要   总被引:2,自引:0,他引:2  
朱华 《广西植物》2018,38(8):984-1004
热带森林是云南的重要植被类型,虽对云南热带森林植被的系统分类及研究在《云南植被》中有所体现,并发表了大量论文,但在植被类型的划分、命名及其解释上却不尽相同,特别是对群系的记录很不全面。该文总结已掌握的研究资料,参考世界类似热带森林植被的研究成果,系统地对云南热带森林植被的类型、分类、物种组成和群落特征等进行了归纳。结果表明:云南的热带森林植被包括3个主要的植被型,即热带雨林、季雨林、季节性湿润林。云南的热带雨林是在亚洲热带北缘季风气候下发育的在水分、热量和分布海拔上均到了极限条件的热带雨林类型,分为热带季节性雨林和其山地变型—热带山地雨林二个植被亚型,前者包括19个群系,后者包括12个群系。文中的热带季雨林是依据其原始定义指介于热带雨林与萨王纳之间的一种热带落叶至半常绿森林植被,其分布主要受水分条件制约,非纬向地带性植被;它们分为落叶季雨林和半常绿季雨林2个植被亚型,前者包括7个群系,后者包括3个群系。把分布于云南南部石灰岩山地的在一些植物学文献中称之为"石灰岩季雨林"的热带森林植被,考虑其常绿至半常绿的外貌特征、特殊的植物区系组成以及乔木层没有一个明显的无叶(落叶)期(其落叶现象可能主要由于局部生境的干燥和历史的原因,并非是由于地区性气候干旱所导致),它们与季雨林的原始定义不符;该文使用名称热带季节性湿润林来定义这类发生在石灰岩山中、上部,在热带季节雨林带之上的热带山地垂直带上的植被类型。季节性湿润林也分为季节性常绿湿润林及季节性半常绿湿润林2个植被亚型,各包括2个群系。  相似文献   

18.
城市化对森林植被、土壤和景观的影响   总被引:22,自引:3,他引:22  
用纽约市“城区-郊区-农区”140km长的森林态样带研究了城市化对森林植被,土壤重金属含量和森林景观的景响,随着距市中心的距离加大,森林植被的类型,种类组成及结构有明显的不同;土壤主要重金属含量逐渐降低。森林景观斑块数量减少,斑块面积在,景观异质性降低,这些变化与交通密度,道路密度,人口密度以及城市土地利用率有显著的相关性。  相似文献   

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Summary Eleven communities in limestone areas of Shikoku have been described and considered from a phytosociological point of view.The evergreen broad-leaved forests and scrubs in the warm temperate region are included in the Camellietea japonicae, and deciduous broad-leaved and coniferous forests excluding the Carpinus turczaninovii-Zabelia integrifolia association in the cool temperate region belong to the Fagetea crenatae. These classes are inclusive of climatic climaxes, and the major dominants are not characteristic of limestone areas. A noticeable fact, however, is the occurrence of the Quercus glauca-Nandina domestica association in limestone areas, where the Castanopsis cuspidata forests prevailing in climatic climaxes are replaced by this association.The limestone vegetation varies considerably with the situation and the physiographic factors, and the most characteristic community typified by the Carpinus turczaninovii-Zabelia integrifolia association appears in xeric sites. This association, having a wide altitudinal range, is not included in any known classes, and the floristic composition is particularized by a large number of endemic and disjunctive elements.
Zusammenfassung Als Ergebnis der pflanzensoziologischen Studien über Wälder und Sträucher in Kalkgegenden von Shikoku, Süd-Japan, wurden elf Pflanzengesellschaften beschrieben.Die immergrünen Wälder und Sträucher im warmtemperierten Gebiet werden in die Klasse Camellietea japonicae eingereiht, während im kalttemperierten Gebiet die Sommergrün- und Nadelwälder ausschließlich der Carpinus turczaninovii-Zabelia integrifolia-Assoziation, Klasse Fagetea crenatae, gehören.Diese Klassen bestehen aus klimatischen Klimaxgesellschaften, und die wichtigeren Dominanten sind keine Kalk-Spezialisten. Es ist aber zu bemerken, daß sich die Quercus glauca-Nandina domestica-Assoziation in Kalkgegenden befindet, wo die in klimatischen Klimaxgesellschaften überwiegenden Castanopsis cuspidata-Wälder durch diese Assoziation ersetzt werden.Mit dem Standort und den physiographischen Faktoren verändert sich die Kalkvegetation ansehnlich, und die durch die Carpinus turczaninovii-Zabelia integrifolia-Assoziation höchst charakteristisch dargestellte Pflanzengesellschaft erscheint in trockenen Standorten. Diese Assoziation wird in keine der bekannten Klassen eingeschlossen, die floristische Zusammensetzung kennzeichnet sich durch eine große Anzahl endemischer und disjunkter Elemente.
  相似文献   

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