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991.
Romain Glèlè Kakaï T. Jean Didier Akpona Achille E. Assogbadjo Orou Gandé Gaoué Sebastian Chakeredza P. Césaire Gnanglè Guy Apollinaire Mensah Brice Sinsin 《African Journal of Ecology》2011,49(4):440-449
The ecological adaptation of shea butter trees was assessed based on their dendrometric and production traits in four shea butter tree parks occurring in different climatic zones of Bénin. A total of 99 rectangular plots of 50 × 30 m were established within the four parks according to a random sampling scheme. In each plot, all trees with a diameter at breast height (dbh) >10 cm were inventoried and measured for stem and crown diameters, and total height. The production of 120 productive shea butter trees was quantified. Collected data were used to compute structural parameters for each park. Moreover, stem diameter and height structures of the trees were established. Principal component analysis was performed on the dendrometric variables, and the first three components were correlated with the climatic parameters. Results revealed significant differences between parks in most of the dendrometric and production parameters of shea butter trees. For all the four parks, stem diameter and height structures present a Gaussian shape with left dissymmetry. In the Guinean zone, shea butter trees develop large crowns but produce little quantities of fruits, whereas in the Sudanian regions, the opposite trend was observed. 相似文献
992.
Honam Komina Atsri Kouami Kokou Komla Elikplim Abotsi Adzo Dzifa Kokutse Aida Cuni-Sanchez 《African Journal of Ecology》2020,58(4):733-745
Despite the increasing interest in the role of African savannah and woodlands on the global carbon cycle, little is known about the above-ground biomass (AGB) and the factors affecting it in these ecosystems in West Africa. We estimated AGB in different vegetation types of a forest–savannah mosaic in Togo, and we investigated the relationship between AGB, structural and diversity attributes. We also assessed the effects of using the ≥5 or ≥10 cm diameter threshold on AGB estimates. We sampled tree diameter, height and species of all trees ≥5 cm diameter following standardised protocols in 160 plots of 50 × 20 m (50 × 10 m for riparian). Above-ground biomass (AGB) (all trees ≥5 cm diameter) ranged from 6.2 Mg/ha in shrub savannah to 292 Mg/ha in riparian forest and showed significant differences between vegetation types. Differences in AGB were related to structural attributes, with little influence of diversity attributes. The effects of minimum tree diameter size (5 or 10 cm) on AGB estimates were negligible. At a landscape level, closed-canopy and open forests stored important quantities of carbon. We highlight the importance of the forest–savannah mosaic as a large carbon pool, which could be released if converted to another land cover type. 相似文献
993.
我国北方地区在旧石器晚期偏晚阶段新出现了一类加工复杂且修理精美的石器类型,可称为“小型两面器”。本文对旧大陆东西方晚更新世考古材料进行对比,结果显示这类“小两面器”在旧大陆西侧拥有更为悠久的历史。距今约7万年前南非旧石器时代中期的Still Bay文化已经出现,蕴含热处理技术和压制技术并已作为投射尖状器使用。到了距今4万年前,小型两面器技术在欧洲开始兴起,逐渐形制变的多样化。我国地处旧大陆东侧,发现的小两面器无论是时代还是器形均显示与旧大陆西侧密切关联,应当是旧石器时代晚期旧大陆东西方文化交流的产物。 相似文献
994.
Ibrahima Diouf Abdoulaye Deme Jacques-André Ndione Amadou Thierno Gaye Belén Rodríguez-Fonseca Moustapha Cissé 《Comptes rendus biologies》2013,336(5-6):253-260
The aim of this work, undertaken in the framework of QWeCI (Quantifying Weather and Climate Impacts on health in the developing countries) project, is to study how climate variability could influence malaria seasonal incidence. It will also assess the evolution of vector-borne diseases such as malaria by simulation analysis of climate models according to various climate scenarios for the next years. Climate variability seems to be determinant for the risk of malaria development (Freeman and Bradley, 1996 [1], Lindsay and Birley, 1996 [2], Kuhn et al., 2005 [3]). Climate can impact on the epidemiology of malaria by several mechanisms, directly, via the development rates and survival of both pathogens and vectors, and indirectly, through changes in vegetation and land surface characteristics such as the variability of breeding sites like ponds. 相似文献
995.
Besides Erasipteroides valentini (Brauckmann in Brauckmann, Koch & Kemper, 1985), Zessinella siope Brauckmann, 1988, and Namurotypus sippeli Brauckmann & Zessin, 1989, Rasnitsynala sigambrorum
gen. et sp. n. is the fourth species of the Odonatoptera from the early Late Carboniferous (Early Pennsylvanian: Namurian B, Marsdenian) deposits of the important Hagen-Vorhalle Konservat-Lagerstätte in Germany. With its wing-span of about 55 mm it is unusually small even for the “Eomeganisoptera”. Its venation resembles other small “Eomeganisoptera”, in particular Zessinella siope. This is why it is here assigned to the probably paraphyletic “Erasipteridae” Carpenter, 1939. 相似文献
996.
We give a first account of our ongoing barcoding activities on Bavarian myriapods in the framework of the Barcoding Fauna Bavarica project and IBOL, the International Barcode of Life. Having analyzed 126 taxa (including 122 species) belonging to all major German chilopod and diplopod lineages, often using four or more specimens each, at the moment our species stock includes 82% of the diplopods and 65% of the chilopods found in Bavaria, southern Germany. The partial COI sequences allow correct identification of more than 95% of the current set of Bavarian species. Moreover, most of the myriapod orders and families appear as distinct clades in neighbour-joining trees, although the phylogenetic relationships between them are not always depicted correctly. We give examples of (1) high interspecific sequence variability among closely related species; (2) low interspecific variability in some chordeumatidan genera, indicating that recent speciations cannot be resolved with certainty using COI DNA barcodes; (3) high intraspecific variation in some genera, suggesting the existence of cryptic lineages; and (4) the possible polyphyly of some taxa, i.e. the chordeumatidan genus Ochogona. This shows that, in addition to species identification, our data may be useful in various ways in the context of species delimitations, taxonomic revisions and analyses of ongoing speciation processes. 相似文献
997.
Narwade S Kalra M Jagdish R Varier D Satpute S Khan N Talukdar G Mathur VB Vasudevan K Pundir DS Chavan V Sood R 《ZooKeys》2011,(150):407-417
The northeast region of India is one of the world's most significant biodiversity hotspots. One of the richest bird areas in India, it is an important route for migratory birds and home to many endemic bird species. This paper describes a literature-based dataset of species occurrences of birds of northeast India. The occurrence records documented in the dataset are distributed across eleven states of India, viz.: Arunachal Pradesh, Assam, Bihar, Manipur, Meghalaya, Mizoram, Nagaland, Sikkim, Tripura, Uttar Pradesh and West Bengal. The geospatial scope of the dataset represents 24 to 29 degree North latitude and 78 to 94 degree East longitude, and it comprises over 2400 occurrence records. These records have been collated from scholarly literature published between1915 and 2008, especially from the Journal of the Bombay Natural History Society (JBNHS). The temporal scale of the dataset represents bird observations recorded between 1909 and 2007. The dataset has been developed by employing MS Excel. The key elements in the database are scientific name, taxonomic classification, temporal and geospatial details including geo-coordinate precision, data collector, basis of record and primary source of the data record. The temporal and geospatial quality of more than 50% of the data records has been enhanced retrospectively. Where possible, data records are annotated with geospatial coordinate precision to the nearest minute. This dataset is being constantly updated with the addition of new data records, and quality enhancement of documented occurrences. The dataset can be used in species distribution and niche modeling studies. It is planned to expand the scope of the dataset to collate bird species occurrences across the Indian peninsula. 相似文献
998.
Nitzan Shoshan 《Ethnos》2013,78(1):24-49
This article reconsiders the question of nostalgic consumption in East Germany as embedded not within a national or a regional (post-socialist) politics of time, as much literature has done, but rather within a global post-Fordist reconfiguration of the relation between time, consumption, and politics. Examining an underclass East Berlin neighborhood that has come to epitomize ‘pastness’, I show the salience of material prosperity – or its lack – in shaping the senses of time of its inhabitants. Especially for the younger generation, nostalgic commodities mediate the growing abyss between loss and accumulation, futures and pasts, nostalgic longings and unrealistic aspirations. I argue that the nexus of time, politics, and consumption has been transformed with the fading away of what has been called the future perfect (the political temporality of utopian projects) and its metamorphosis into what I term here the past conditional, the temporality of lost futures, irredeemable opportunities, and vanquished political imaginaries. 相似文献
999.
1000.