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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

The recovery of tropical lowland rainforest after clearfell logging in the Gogol Valley, Papua New Guinea

Saulei, Simon M. January 1985 (has links)
Recovery of tropical rain forest in Gogol Valley, Papua New Guinea was monitored for 2 years following clear-fel1ing in the wet and dry seasons. Further redevelopment, reconstructed by measurements of regrowth of known ages from 1.5-10.8 years, were compared with forest heavily disturbed by fire 55 years ago and primary forest. The vegetation, survey was assessed principally by Counting and measuring trees. Because of the importance of soil seed bank in influencing vegetation recovery processes, special attention was given to the spatial and temporal changes in the soil seed bank and the seed rain which supplies it. The major findings were: (1) vegetation recovery was rapid and 97% of all colonizing trees regenerated from seeds while 3% were resprouts; (2) regrowth after felling in the dry-season differed from that following wet-season felling in having lower density, slower growth and mostly comprised resprouting tree species; (3) after 10 years, regrowth is composed principally of large pioneer trees (65% of basal area or 64% of stems); (4) the 55 year-old forest also had many (48%) pioneer trees: much of the forest in the area is of this kind and may be classified as advanced secondary forest; (5) forest soil seed bank following felling was rapidly depleted due to germination, but was rapidly replaced as early pioneer herbs matured and set seed. Trees in soil seed bank do not approach that of primary forest until after 10 years of regrowth; (6) the intensity of pioneer trees' seed rain was correlated with the fecundity of nearby parent trees and clearly controlled soil seed bank redevelopment. There was evidence of dispersal of pioneer seeds several hundred metres into an isolated area of closed forest; (7) trees left uncut following felling contribute significantly to seed rain and therefore to soil seed bank.
12

Genetic and ecological studies relevant to the conservation and management of some Bornean Calamus species

Fah, Lee Ying January 1995 (has links)
Genetic variation in Calamus subinermis was investigated in a provenance cum progeny trial and a study on some quantitative morphological traits. These studies show that variation occurs within and among populations of the species. Genetic gain was estimated for provenance and family selection at a range of selection intensity based on some economic traits. A karyomorphological study on C. subinermis and C. caesius reveals little variation in the chromosome morphology between and within species. The flowering and fruiting phenology of C. subinermis, C. caesius, C. manan and C. trachycoleus was elucidated. Except for the relatively opportunistic C. subinermis, in which floral initiation occurred at about four-month intervals, flowering and fruiting of the Calamus species investigated exhibited a regular annual pattern. Unravelling of the pollination mechanism and floral biology of C. subinermis and C. caesius in this project enables understanding of the breeding system and is important in breeding programmes. Pollination mainly by small noctuid and pyralid moths, which have small foraging ranges, partly accounts for the observed divergence among geographically isolated populations of C. subinermis. The discovery of andromonoecy in C. subinermis, together with the potential bisexuality in the other generally dioecious calamoid genera, calls for modification in the present system of classification for the tribe Calameae, and has implications for natural and artificial pollination. Several rattan mensuration techniques were developed. Growth and yield models based on the Richards function were constructed for C. caesius. These techniques and models will contribute to the conservation with wise use of rattan resources. Recommendations for further research are given for attaining the goal of the project.
13

The pre-dispersal insect fruit-predators of Dipterocarpaceae in Malaysian rain forest

Toy, Robin J. January 1988 (has links)
This study examines fruit predation of species in the family Dipterocarpaceae. It was conducted in Pasoh Forest Reserve, a Lowland Dipterocarp Rain Forest in West Malaysia. The work concentrates upon the pre-dispersal weevil predators, whose larvae develop within dipterocarp fruit. After describing the pre-dispersal predators the host specificity of their larvae is examined. A comparison of host records determined in this study with records in the literature demonstrates statistically significant generic specialization by the larvae of some weevil species. The larvae of other species are also restricted to hosts within one genus, but sampling effort was insufficient to demonstrate generic specialization. The most abundant pre-dispersal weevil predator was <i>Nanophyes shoreae</i>. Aspects of the biology of this species are described. These include: the activity of the adult weevils during dipterocarp flowering events; the timing of oviposition; the length of the pre-imaginal development period; the survivorship of adult beetles kept under laboratory conditions. The period of pre-imaginal development varied between host species but was consistent between trees of one species. Quantitative analyses of <i>Nanophyes shoreae's</i> pre-imaginal mortality are also described. The primary mortality factors were abortion of fruit containing eggs and consumption of pupae and III instar larvae by vertebrates. Adaptations that may reduce losses to these primary mortality factors are considered. They include oviposition within those fruit that are least likely to abort and variability in the length of the pre-imaginal development period, causing synchronous development in larvae developing from eggs that were deposited on different dates. None of the dipterocarp fruit predators could be located during periods when dipterocarp fruit were not available. Analyses of their population recruitment during fruiting events and of the availability of fruiting trees (as determined by a phenological survey of Pasoh Forest Reserve) indicates that they are unlikely to have dispersed widely in search of fruiting dipterocarps. The existence of an alternative larval or adult host is discussed.
14

The utility of linear riparian rainforest for vertebrates on the Atherton and Evelyn Tablelands, North Queensland /

Hausmann, Franziska. January 2004 (has links)
Thesis (M.Phil.) -- Griffith University, 2004. / Facsimile of the author's original dissertation. Pagination of document: x, 121 leaves. Includes bibliographical references. Also available online via the World Wide Web.
15

Population dynamics of tropical forest trees

Manokaran, N. January 1988 (has links)
Thesis (Ph.D.)--Aberdeen University, 1988. / Title from web page (viewed on Mar. 4, 2010). Includes bibliographical references.
16

Images and metaphor : an analysis of Iban collective representation

Davison, Julian January 1987 (has links)
The Iban of Sarawak, East Malaysia, are the inhabitants of a vast equatorial rain forest which not only plays a crucial role in satisfying their material needs, but also provides them with a rich source of imagery for the portrayal of key cultural concerns and social values. That is to say, one finds that Iban collective representations are characterized by a profusion of floral and botanical forms, while the ritual use of plants features strongly in Iban religious life. Often these 'sacred' and 'profane' aspects of the plant world coincide, as in the case of Iban rice farming which both provides them with their staple diet, and at the same time is imbued with a deeply religious significance. The primary interest of this study, then, lies in its examination of the special relationship between man and plant in Iban culture. The research is based on library materials and takes, as its epistemological starting point, the idea that an understanding of metaphor can be usefully employed in the interpretation of symbolic phenomena. This approach works on two levels. On the one hand, there is the idea that a systematic examination of recurrent metaphorical forms - be they expressed in mythological narrative, ritual imagery, or everyday language - can be linked to dominant cultural values and social orientations. On the other hand, there is also the idea that a theory of metaphor - as developed in the field of literary criticism and semantics - can provide valuable insight into the way in which so-called 'symbolic phenomena' are 'actualized', or 'understood', by those for whom they operate. In the last instance, the study seeks to transcend the formal strictures of conventional structural analysis by suggesting ways in which the elaborate structures that are revealed by the latter are actually realized, or at least represented, in daily life - whether it be in the rarefied atmosphere of a religious ceremony or the more mundane setting at some commonplace activity. In doing so, the study raises a number of issues that are of a metaphysical nature - among them the question of indigenous notions of causation - thereby providing not just simply a re-evaluation of the existing ethnographic record, but also a point of departure for future inquiries in the field.
17

Population dynamics of tropical forest trees

Manokaran, N. January 1988 (has links)
Tree population dynamics were monitored in three tropical rain forest sites in Peninsular Malaysia. The studies involved trees ≥ 10 cm dbh, over 36 years in hill dipterocarp forest at Bukit Lagong, and over 38 and 13 years in lowland dipterocarp forests at Sungei Menyala and Pasoh respectively. Trees were periodically measured for dbh, and mortality and recruitment recorded. Sapling populations at Sungei Menyala were also enumerated at periods separated by about 30 years. The major findings were: decline in tree density over the periods of study were offset by incremental growth in surviving trees, showing that the forests are fully stocked and structurally stable; mortality rates and 'half-life' values were 2.03%, 2.07% and 1.39% yr^-1, and 34.2, 33.5 and 49.9 years for Sungei Menyala, Pasoh and Bukit Lagong respectively; mortality was not correlated with size class for the lowland forests, but there was some evidence for higher mortality in the larger size classes for the hill forest, this possibly being related to soil instability on steep slopes; the risk of death was about 7-8 times greater for trees with negative or no growth, with suppression leading to higher mortality in canopy than in understorey species; recruitment rates to the 10 cm dbh class were 1.32%, 1.46% and 0.85% yr^-1 at Sungei Menyala, Pasoh and Bukit Lagong respectively; dbh increments were linear over long periods for most trees, future size of individuals therefore predictable from one set of measurements; fast-growing mature trees are estimated to be as young as 60 years; variation in species composition over time was slight compared with variation between sites; sapling composition and density at Sungei Menyala changed greatly over 30 years but that for adults remained constant over 38 years, showing that future canopy composition is unlikely to change without catastrophic disturbances occurring.
18

Soil biological properties in damaged Picea abies (L.) Karst, ecosystems in Bohemia, Czech Republic

Ruzicka, Stepan January 1996 (has links)
No description available.
19

Valuing forests in tropical landscapes in the context of REDD+

Wilebore, Rebecca January 2015 (has links)
No description available.
20

Diversidade de vespas sociais (Hymenoptera, vespidae) na Mata Atlântica do litoral norte do estado de São Paulo /

Togni, Olga Coutinho. January 2009 (has links)
Orientador: Edilberto Giannotti / Banca: Fábio Prezoto / Banca: Maria José de Oliveira Campos / Resumo: A Mata Atlântica é um ecossistema muito relevante para a biologia da conservação e possui uma das maiores diversidades de espécies do continente, inclusive a de vespas sociais. Este grupo de insetos, que no Brasil está representado pelos Polistinae, causa grandes impactos nos ecossistemas, já que as vespas são importantes predadoras e coletoras de néctar. Tendo em vista que o inventário das espécies de uma área é o ponto inicial para a sua preservação, o objetivo do estudo foi efetuar um levantamento da diversidade de vespas sociais da Mata Atlântica da Serra do Mar do litoral norte do estado de São Paulo, enfatizando a importância desse grupo para avaliações de impacto ambiental e de efeitos de fragmentação florestal da região. Além disso, foi possível comparar a eficiência das metodologias utilizadas, verificando se ocorre preferência das vespas pelo conteúdo das armadilhas. As coletas foram realizadas na Fazenda Angelim Rainforest de maio de 2007 a maio de 2008, utilizando armadilhas atrativas de garrafa PET e coleta ativa. Foram encontradas 21 espécies pertencentes a oito gêneros e, dentre elas, algumas são raras na região sudeste do país, como Mischocyttarus parallelogrammus e Polybia catillifex. As espécies mais freqüentes foram Agelaia angulata (64,31%), A. sp. prox. centralis (10,08%) e Angiopolybia pallens (8,49%). Observou-se correlação entre a riqueza das espécies e a umidade relativa do ar. Analisando os distintos ambientes, verificou-se maior riqueza, abundância e índice de diversidade de Margalef na área antropizada (A=793, R=14, DMg=4,4839, H'=1,08), mas a maior diversidade obtida pelo índice de Shannon-Wiener foi na área de mata fechada (A=174, R=8, DMg=3,1242, H'=1,17). As armadilhas com atrativo glucídico obtiveram maior riqueza, igual a 16 espécies ou 76,19% da riqueza total coletada. As armadilhas... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The Atlantic Rain Forest is very relevant for conservation biology and has one of the greatest biodiversity in the continent, including social wasps diversity. This group of insects, which in Brazil is represented by Polistinae, causes major impacts on ecosystems, because the wasps are important predators and collectors of nectar. Bearing in mind that the inventory of species in an area is the starting point for its preservation, the goal of this study was to perform a survey of the social wasps diversity of the Atlantic Forest on the north coast of São Paulo State, emphasizing the importance of this group for environmental impact assessments and the effects of forest fragmentation in the region. Furthermore, it was possible to compare the efficiency of the methodologies, verifying if there is a preference of the wasps for the contents of the traps. The collections were made in Fazenda Angelim Rainforest from May 2007 to May 2008, using attractive PET bottles traps and active searching. We found 21 species belonging to eight genera and among them; some are rare in the southeast region of the country, such as Mischocyttarus parallelogrammus and Polybia catillifex. The most frequent species were Agelaia angulata (64.31%), A. sp. prox. centralis (10.08%) and Angiopolybia pallens (8.49%). Correlation was observed between species richness and relative air humidity. When analyzing the different environments, it was possible to verify a greater richness, abundance and Margalef diversity index in the anthropic area (A= 793, R= 14, DMg= 4.4839, H= 1.08), but the greatest diversity obtained by Shannon-Wiener index was in the area of dense vegetation (A= 174, R= 8, DMg= 3.1242, H'= 1.17). The traps with glucidic attractive obtained greater richness, equal to 16 species or 76.19% of total richness collected. Traps with protein content were the least effective (six species, 28.57% of total richness)... (Complete abstract click electronic access below) / Mestre

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