scholarly journals The invention of biodiversity: social perspectives on the management of biological variety in Africa

Africa ◽  
1996 ◽  
Vol 66 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Jane Guyer ◽  
Paul Richards
Keyword(s):  
Genetic Diversity ◽  
Rain Forest ◽  
Tropical Rain Forest ◽  
Social Perspectives ◽  
Number Of Species ◽  
Unknown Species ◽  
Object Of Study ◽  
Or Genes ◽  
Species Biodiversity

Biodiversity means, in its broadest sense, the variety of life. More specifically it can refer to the number of species, genetic diversity or the variety of environments in which species or genes are to be found. The concept is in some ways an odd one, since biodiversity is quantitative without necessarily being quantifiable. As an object of study biodiversity is a bit like an iceberg—most of it is hidden from view, and (like the underwater portion of an iceberg) indefinite in shape and extent. The notion of global species biodiversity is often expressed in the form (estimates vary): 1·5 million species known to science, 5 million (or 30 million) yet remaining to be discovered (Primack, 1993). The rider to this surprising formulation is that most of the unknown species are probably insects in the tropical rain forest.

Genetic diversity among natural populations of Agathis borneensis (Araucariaceae), a tropical rain forest conifer from Brunei Darussalam, Borneo, Southeast Asia

1992 ◽  
Vol 70 (10) ◽  
pp. 1945-1949 ◽  
Author(s):  
Keiko Kitamura ◽  
Mohamad Yusof Bin Abdul Rahman
Keyword(s):  
Genetic Diversity ◽  
Southeast Asia ◽  
Rain Forest ◽  
Tropical Rain Forest ◽  
Natural Populations ◽  
Conservation Strategy ◽  
Restricted Gene Flow ◽  
Isozyme Electrophoresis ◽  
Brunei Darussalam ◽  
Population Component

Agathis is a genus of tropical conifers that occurs mainly in Southeast Asia. Because of its production of good softwood, many stands of Agathis have been harvested. We provide an estimate of genetic variation within and among populations of Agathis borneensis in Brunei Darussalam, Southeast Asia. Five populations were investigated using isozyme electrophoresis. We investigated a total of 17 putative loci, five of which were polymorphic. Estimated total heterozygosity was 0.122. Heterozygosity within populations was 0.106. The population structure did not deviate significantly from Hardy–Weinberg expectations. Nei's coefficient of gene differentiation indicated that the among-population component of genetic diversity represents 14% of the total population component. The low level of genetic diversity and the large diversity among populations were the opposite of that for conifers in the temperate zone, because of the small size of each population. The large diversity among populations indicated the restricted gene flow resulting from the asynchronous flowering of this species. The genetic distance indicated that A. borneensis in Brunei could be classified in two groups, with one isolated population considerably different from the others both genetically and ecologically. The conservation strategy is discussed from the viewpoint of genetic resources. Key words: Agathis borneensis, Araucariaceae, Brunei Darussalam, genetic diversity, isozyme, tropical rain forest.

scholarly journals Scientific Results of the BRYOTROP Expedition to Zaire and Rwanda 2. The altitudinal zonation of the bryophytes on Mt. Kahuzi, Zaire

1994 ◽  
Vol 9 (1) ◽  
pp. 153-167 ◽  
Author(s):  
Jan-Peter Frahm
Keyword(s):  
Rain Forest ◽  
Tropical Rain Forest ◽  
Montane Forest ◽  
Tropical Montane Forest ◽  
Subalpine Forest ◽  
Altitudinal Zonation ◽  
Number Of Species ◽  
Ecological Parameters ◽  
Scientific Results ◽  
Different Altitudes

The altitudinal zonation of the tropical rain forest at Mt. Kahuzi has been studied using bryophytes. The study is based on floristic parameters such as the number of species per hectarplot in different altitudes and the calculation of floristic discontinuities extracted from and evluation of altitudinal ranges. The results are compared and correlated to ecological parameters, especially data on the phytomass of epiphytic bryophytes per m² and per hectare. Based on these data, the tropical rain forest is classified as submontane forest (-1500 m), lower tropical montane forest (1500-2000 m), upper tropical montane forest (2100-2800 m), and subalpine forest (2900-3200 m). Except for the terminology, the vegetation belts derived from bryophytes can be correlated with those presented in general vegetatioinal schemes for tropcial Africa.

scholarly journals The Passalidae (Coleoptera, Scarabaeoidea) from Bolivia, with the descriptions of three new species

ZooKeys ◽  
2019 ◽  
Vol 882 ◽  
pp. 51-85
Author(s):  
Larry Jiménez-Ferbans ◽  
Pedro Reyes-Castillo ◽  
Jack C. Schuster
Keyword(s):  
New Species ◽  
Rain Forest ◽  
Tropical Rain Forest ◽  
New Records ◽  
Montane Forest ◽  
Field Trip ◽  
Number Of Species ◽  
Systematic Exploration ◽  
Three New Species ◽  
Eleven Species

Employing data from literature, examination of specimens in collections, and a field trip, a list of the species of Passalidae from Bolivia is elaborated. A total of 38 species is reported, including new records of Passalus inca Zang, 1905 and P. lunaris (Kaup, 1871), and three new brachypterous species: Passalus bolivianussp. nov., P. canoisp. nov., and P. gonzalezaesp. nov. Most of the species (27) belongs to the Passalini tribe, especially to the genus Passalus Fabricius, 1792 (19 species); the Proculini tribe is represented by eleven species in three genera. The number of species of Bolivia is low and reflects the lack of a systematic exploration of this country; more surveys are needed, especially in ecosystems such as montane forest and tropical rain forest.

scholarly journals Genetic variation and outcrossing rate of Dipterocarpus dyeri in the Tan Phu tropical rain forest (Dong Nai), Vietnam

2019 ◽  
Vol 41 (1) ◽  
Author(s):  
Nguyen Minh Duc ◽  
Vu Dinh Duy ◽  
Dang Phan Hien ◽  
Tran Thi Viet Thanh ◽  
Nguyen Thi Phuong Trang ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Rain Forest ◽  
Tropical Rain Forest ◽  
Habitat Destruction ◽  
Outcrossing Rate ◽  
Conservation Strategy ◽  
Ex Situ ◽  
Mixed Mating ◽  
Mating Rate

Dipterocarpus dyeri (Dipterocarpaceae) is widely distributed in lowland rainforests in southeastern Vietnam. Due to over- exploitation and habitat destruction in the 1980s and 1990s, this species is listed as threatened. Understanding the genetic variation and mating rate among D. dyeri population that occurs in forest patches is necessary to establish effectively conservation strategies for this species. To conserve the species in tropical forests, genetic diversity and mating rate were investigated using eight microsatellites (single sequence repeat, SSR) as markers. All of the eight loci were polymorphic. A total of 36 different alleles were observed across the loci screened. The SSR data indicated high genetic diversity (NA = 4.5; HO = 0.542 and HE = 0.667) and high inbreeding value, FIS= 0,182. The mating system parameters were determined using the mixed mating model and the results indicated high outcrossing rate (tm=0.81 and ts=0.675) and lowselfing rate (0.19). Difference of tm-ts value indicated that inbreeding contributed to selfing rate for this species in the Tan Phu tropical rain forest. The results reflected that D. dyeri habitat in this area has been restored and the number of individuals was high, about 500 individuals. However, seedlings were not found so far in this study. These results indicated the importance of conserving of the genetic resources of Dipterocarpus dyeri species in the Tan Phu rain forest. The conservation strategy should include an establishment of an ex-situ conservation site with new big population for this species from all genetic groups, which might improve its fitness under different environmental stresses.  

The Effects of a Tropical rain Forest Cover on Airborne Gamma-Ray Spectrometry

2018 ◽  
Vol 1 (2) ◽  
Author(s):  
Enio B. Pereira ◽  
Daniel J.R. Nordemann
Keyword(s):  
Rain Forest ◽  
Tropical Rain Forest ◽  
Forest Cover ◽  
Gamma Ray ◽  
Gamma Ray Spectrometry

Para solicitação de resumo, entrar em contato com editor-chefe ([email protected]). 

scholarly journals (5d RG-flow) trees in the tropical rain forest

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Marieke van Beest ◽  
Antoine Bourget ◽  
Julius Eckhard ◽  
Sakura Schäfer-Nameki
Keyword(s):  
Large Class ◽  
Rain Forest ◽  
Tropical Rain Forest ◽  
Field Theories ◽  
Flavor Symmetry ◽  
Superconformal Field Theories ◽  
Hasse Diagrams ◽  
Flavor Symmetries ◽  
Rank 2 ◽  
Mass Deformation

Abstract 5d superconformal field theories (SCFTs) can be obtained from 6d SCFTs by circle compactification and mass deformation. Successive decoupling of hypermultiplet matter and RG-flow generates a decoupling tree of descendant 5d SCFTs. In this paper we determine the magnetic quivers and Hasse diagrams, that encode the Higgs branches of 5d SCFTs, for entire decoupling trees. Central to this undertaking is the approach in [1], which, starting from the generalized toric polygons (GTPs) dual to 5-brane webs/tropical curves, provides a systematic and succinct derivation of magnetic quivers and their Hasse diagrams. The decoupling in the GTP description is straightforward, and generalizes the standard flop transitions of curves in toric polygons. We apply this approach to a large class of 5d KK-theories, and compute the Higgs branches for their descendants. In particular we determine the decoupling tree for all rank 2 5d SCFTs. For each tree, we also identify the flavor symmetry algebras from the magnetic quivers, including non-simply-laced flavor symmetries.

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