Natural Resource Use in Madagascar
| Autor: | Reuter, Kim E. |
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| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: | |
| Druh dokumentu: | Text |
| DOI: | 10.34944/dspace/3449 |
| Popis: | The anthropogenic use of natural resources has become a major cause of biodiversity loss and habitat degradation throughout the world. Deforestation - the conversion of forests to alternative land covers - has led to a decrease in local biodiversity directly through a decrease in habitat, and indirectly through habitat fragmentation. Likewise, defaunation – the loss of animals both directly through hunting and indirectly through deforestation – has led to the empty forest syndrome and subsequent deterioration of forest ecosystems. In many cases, areas where anthropogenic use of natural resources is high overlap with areas of high biodiversity value. Therefore, the present series of studies aims to better understand the impacts that different types of natural resources use and habitat degradation have on biodiversity. This dissertation details the results of five studies, which aimed to: 1) examine the effects of habitat degradation on plant-frugivore networks; 2), understand the live capture and extent of ownership of lemurs in Madagascar; 3) understand the micro- and macro-level drivers of wild meat consumption in Madagascar; 4) describe the capture, movement, and trade of wild meat in Madagascar; and 5) the impacts of habitat changes on the diets and vertical stratification of frugivorous bats. For the first study, our objectives were to understand the effects of habitat degradation on (1) community structure, (2) network structure, and (3) seed dispersal services. We focused on fruit-bearing trees and frugivores (two lemur and five bird species) across a three-point gradient of habitat degradation in a tropical dry forest in Madagascar. Our objectives were to understand the effects of habitat degradation on (1) community structure, (2) network structure, and (3) seed dispersal services. We focused on fruit-bearing trees and frugivores (two lemur and five bird species) across a three-point gradient of habitat degradation in a tropical dry forest in Madagascar. Data on fruit consumption by frugivores were collected over 592 hours of observations at 13 fruiting tree species. We found that as habitat became more degraded: (1) the community structure of both frugivores and fruiting tree communities changed; (2) the mutualistic network structure became less complex and less connected; (3) the interaction strengths of pair-wise interactions changed and the asymmetries of these interactions shifted; and (4) seed dispersal decreased by 91% in the secondary forest, compared to the primary forest. In addition, we show that frugivores: (1) sometimes stopped eating fruit in the degraded forest, even when they had consumed it in other forests; and (2) appeared to avoid some fruiting tree species while showing preference for others. The mutualistic network studied in this paper appeared sensitive to anthropogenic disturbance and a novel measure of effectiveness helped quantify these changes. For the second study, our objectives were to provide the first quantitative estimates of the prevalence, spatial extent, correlates and timing of lemur ownership, procurement methods, within-country movements, and numbers and duration of ownership. Using semi-structured interviews of 1,093 households and 61 transporters, across 17 study sites, we found that lemur ownership was widespread and affected a variety of taxa. We estimate that 28,253 lemurs have been affected since 2010. Most lemurs were caught by owners and kept for either short (≤1 week) or long (≥3 years) periods. The live capture of lemurs in Madagascar is not highly organized but may threaten several endangered species. For the third study, we investigated the role of wild meat in food security in Madagascar, a country where wild meat consumption is poorly understood in urban areas and at regional scales. Using semi-structured interviews (n = 1339 heads-of-households, 21 towns), we aimed to: 1) quantify the amount and purpose of; 2) understand the drivers behind; and, 3) examine recent changes in wild meat consumption in Madagascar. Few respondents preferred wild meat (8 ± 3%) but most had eaten it at least once (78 ± 7%), and consumption occurred across ethnic groups, in urban and rural settings. More food insecure areas reported higher rates of recent consumption of wild meat. However, consumption was best explained by individual preferences and taboos. Few respondents Biology Ph.D. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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