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Dinâmica da recomposição natural em bosques de mangue impactados: Ilha Barnabé (Baixada Santista), SP, Brasil; Dynamics of the natural recovery in impactes mangroves stands at Barnabé Island (Baixada Santista), SP, Brazil

Menghini, Ricardo Palamar
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 03/12/2008 PT
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A Baixada Santista encontra-se na região central do litoral de São Paulo (23o55S). É um típico ambiente costeiro tropical dominado por extensos manguezais. Entretanto, vem sofrendo intenso processo de alteração ambiental devido a atividades industriais e portuárias, além da ausência de planejamento urbano. A fim de avaliar a capacidade de recomposição natural dos manguezais na Ilha Barnabé foram realizados estudos em bosque impactado por derramamento e combustão de produto químico (DCPD) em 1998, monitorando a recomposição natural da vegetação (2002-2007); a produção de serapilheira (2002-2007) e a microtopografia (2004 e 2008). Também foram analisadas fotografias aéreas em escala multitemporal (1962, 1972, 1994 e 2003) e a caracterização estrutural de bosques em diferentes estágios sucessionais. No bosque impactado por produto químico, a recomposição natural se mostrou eficaz, porém lenta; a produção de serapilheira apresentou valores crescentes ao longo dos anos com grande contribuição de propágulos deformados ou abortados e a microtopografia mostrou intensa dinâmica sedimentar. A análise das fotografias aéreas mostrou os diversos impactos ocorridos na região com formação de clareiras na vegetação e recomposição natural parcial. A caracterização estrutural dos bosques em diferentes estágios sucessionais mostrou que a recomposição natural dos manguezais da Ilha Barnabé apresenta um mosaico de características estruturais refletindo as diferentes intensidades e tipos de tensores que atuam na região. A metodologia utilizada mostrou-se adequada para avaliação da capacidade de recomposição natural de bosques de mangue.; The Baixada Santista and Santos Estuary are located in the central portion of the São Paulo State coastline (23º55'S). It is a typical tropical coastal environment dominated by extensive mangroves areas despite the intensive harbor and heavy industrial activities...

Subtropical Brazilian mangroves as a refuge of crab (Decapoda: Brachyura) diversity

Colpo, Karine Delevati; Chacur, Monica Mungai; Guimaraes, Fernanda Jordao; Negreiros-Fransozo, Maria Lucia
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica Formato: 3239-3250
ENG
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Processo FAPESP: 94/4878-8; Processo FAPESP: 95/8520-3; Processo FAPESP: 98/3134-6; Processo FAPESP: 98/15292-5; This study characterized seven mangrove areas of different sizes, located on the southeastern Brazilian coast, with respect to their sediment and vegetation features. We also estimated the richness and composition of the brachyuran assemblages in these mangroves. Crab, vegetation and sediment data were collected during low tide. The larger mangroves showed richer and complex forests, and may be more ecologically stable than smaller mangroves. Twenty-eight species of crabs were recorded, members of nine families: Panopeidae, Pinnotheridae, Gecarcinidae, Grapsidae, Sesarmidae, Varunidae, Ocypodidae, Ucididae, and Portunidae. Ocypodoidea predominated over Grapsoidea in the smaller mangrove areas in pioneer stages of forest establishment, whereas the opposite was recorded for larger and more stable mangroves, where the forest can reach advanced stage of development. Comprido is a small mangrove, but its crab assemblage was similar to the larger ones, probably because of other factors not investigated here (e.g., megalopa settling rate). This study provided basic knowledge for developing conservation strategies for vulnerable mangrove ecosystems.

Kluyveromyces aestuarii, a potential environmental quality indicator yeast for mangroves in the State of Rio de Janeiro, Brazil

Araujo,F.V; Hagler,A. N
Fonte: Sociedade Brasileira de Microbiologia Publicador: Sociedade Brasileira de Microbiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2011 EN
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Kluyveromyces aestuarii was found in sediments from 7 of 8 mangroves in Rio de Janeiro; and absent only at one site with heavy plastic bag pollution. Its presence suggests influence in other habitats from a mangrove and its absence in a mangrove suggests some non-fecal pollution or other habitat alteration.

Physiological responses of red mangroves to the climate in the Florida Everglades

Barr, Jordan G.; Fuentes, Jose D.; Engel, Vic; Zieman, Joseph C.
Fonte: FIU Digital Commons Publicador: FIU Digital Commons
Tipo: Artigo de Revista Científica Formato: application/pdf
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This manuscript reports the findings of physiological studies of red mangrove (Rhizophora mangle L.) conducted from June to August 2001 and from May to June 2003 in the Florida Everglades. In situ physiological measurements were made using environmentally controlled gas exchange systems. The field investigations were carried out to define how regional climate constrains mangrove physiology and ecosystem carbon assimilation. In addition, maximum carboxylation and photosynthetic active radiation (PAR) limited carbon assimilation capacities were investigated during the summer season to evaluate whether ecophysiological models developed for mesophyte plant species can be applied to mangroves. Under summertime conditions in the Florida Everglades, maximum foliar carbon dioxide (CO2) assimilation rates reached 18 μmol CO2 m−2 s−1. Peak molar stomatal conductance to water vapor (H2O) diffusion reached 300 mmol H2O m−2 s−1. Maximum carboxylation and PAR‐limited carbon assimilation rates at the foliage temperature of 30°C attained 76.1 ± 23.4 μmol CO2 m−2 s−1 and 128.1 ± 32.9 μmol (e−) m−2 s−1, respectively. Environmental stressors such as the presence of hypersaline conditions and high solar irradiance loading (>500 W m−2 or >1000 μmoles of photons m−2 s−1 of PAR) imposed sharp reductions in carbon assimilation rates and suppressed stomatal conductance. On the basis of both field observations and model analyses...

Sediment and Nutrient Deposition Associated with Hurricane Wilma in Mangroves of the Florida Coastal Everglades

Castañeda-Moya, Edward; Twilley, Robert R.; Rivera-Monroy, Victor H.; Zhang, Keqi; Davis, Stephen E., III; Ross, Michael
Fonte: FIU Digital Commons Publicador: FIU Digital Commons
Tipo: Artigo de Revista Científica
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The distribution of mangrove biomass and forest structure along Shark River estuary in the Florida Coastal Everglades (FCE) has been correlated with elevated total phosphorus concentration in soils thought to be associated with storm events. The passage of Hurricane Wilma across Shark River estuary in 2005 allowed us to quantify sediment deposition and nutrient inputs in FCE mangrove forests associated with this storm event and to evaluate whether these pulsing events are sufficient to regulate nutrient biogeochemistry in mangrove forests of south Florida. We sampled the spatial pattern of sediment deposits and their chemical properties in mangrove forests along FCE sites in December 2005 and October 2006. The thickness (0.5 to 4.5 cm) of hurricane sediment deposits decreased with distance inland at each site. Bulk density, organic matter content, total nitrogen (N) and phosphorus (P) concentrations, and inorganic and organic P pools of hurricane sediment deposits differed from surface (0–10 cm) mangrove soils at each site. Vertical accretion resulting from this hurricane event was eight to 17 times greater than the annual accretion rate (0.30± 0.03 cm year−1) averaged over the last 50 years. Total P inputs from storm-derived sediments were equivalent to twice the average surface soil nutrient P density (0.19 mg cm−3). In contrast...

Carbon (d13c) and Nitrogen (d15n) Isotopic Discrimination in Mangroves in Florida Coastal Everglades as a Function of Environmental Stress

Mancera- Pineda, Josè Ernesto; Twilley, Robert R.; Rivera-Monroy, Victor H.
Fonte: FIU Digital Commons Publicador: FIU Digital Commons
Tipo: Artigo de Revista Científica
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Isotope signatures of mangrove leaves can vary depending on discrimination associated with plant response to environmental stressors defined by gra­dients of resources (such as water and nutrient limitation) and regulators (such as salinity and sul­fide toxicity). We tested the variability of man­grove isotopic signatures (d13C and d15N) across a stress gradient in south Florida, using green leaves from four mangrove species collected at six sites. Mangroves across the landscape studied are stressed by resource and regulator gradients repre­sented by limited phosphorus concentrations com­bined with high sulfide concentrations, respec­tively. Foliar d13C ratios exhibited a range from ­ 24.6 to –32.7‰, and multiple regression analysis showed that 46% of the variability in mangrove d13C composition could be explained by the differ­ences in dissolved inorganic nitrogen, soluble reac­tive phosphorus, and sulfide porewater concentra­tions. 15N discrimination in mangrove species ranged from –0.1 to 7.7‰, and porewater N, salin­ity, and leaf N:Pa ratios accounted for 41% of this variability in mangrove leaves. The increase in soil P availability reduced 15N discrimination due to higher N demand. Scrub mangroves (<1.5 m tall) are more water-use efficient...

Allocation of Biomass and Net Primary Productivity of Mangrove Forests along Environmental Gradients in the Florida Coastal Everglades, USA

Castañeda-Moya, Edward; Twilley, Robert R.; Rivera-Monroy, Victor H.
Fonte: FIU Digital Commons Publicador: FIU Digital Commons
Tipo: Artigo de Revista Científica
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27.59%
Vegetation patterns of mangroves in the Florida Coastal Everglades (FCE) result from the interaction of environmental gradients and natural disturbances (i.e., hurricanes), creating an array of distinct riverine and scrub mangroves across the landscape. We investigated how landscape patterns of biomass and total net primary productivity (NPPT), including allocation in above- and below-ground mangrove components, vary inter-annually (2001–2004) across gradients in soil properties and hydroperiod in two distinct FCE basins: Shark River Estuary and Taylor River Slough. We propose that the allocation of belowground biomass and productivity (NPPB) relative to aboveground allocation is greater in regions with P limitation and permanent flooding. Porewater sulfide was significantly higher in Taylor River (1.2 ± 0.3 mM) compared to Shark River (0.1 ± 0.03 mM) indicating the lack of a tidal signature and more permanent flooding in this basin. There was a decrease in soil P density and corresponding increase in soil N:P from the mouth (28) to upstream locations (46–105) in Shark River that was consistent with previous results in this region. Taylor River sites showed the highest P limitation (soil N:P > 60). Average NPPT was double in higher P environments (17.0 ± 1.1 Mg ha−1 yr−1) compared to lower P regions (8.3 ± 0.3 Mg ha−1 yr−1). Root biomass to aboveground wood biomass (BGB:AWB) ratio was 17 times higher in P-limited environments demonstrating the allocation strategies of mangroves under resource limitation. Riverine mangroves allocated most of the NPPT to aboveground (69%) while scrub mangroves showed the highest allocation to belowground (58%). The total production to biomass (P:B) ratios were lower in Shark River sites (0.11 yr−1); whereas in Taylor River sites P:B ratios were higher and more variable (0.13–0.24 yr−1). Our results suggest that the interaction of lower P availability in Taylor River relative to Shark River basin...

Influence of habitat configuration on connectivity between fish assemblages of Caribbean seagrass beds, mangroves and coral reefs

Dorenbosch, M.; Verberk, W.; Nagelkerken, I.; van der Velde, G.
Fonte: Inter-research Publicador: Inter-research
Tipo: Artigo de Revista Científica
Publicado em //2007 EN
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The importance of seagrass beds and mangroves as juvenile habitats for coral reef fishes is still debatable. We hypothesised that the configuration of these habitats in the marine landscape in relation to the coral reef would influence accessibility from the reef (both for fishes that use these habitats for shelter or feeding, and their predators). In combination with differences in habitat complexity (related to habitat type) this could influence the utilisation of these habitats by juvenile reef fishes, and connectivity with the coral reef. Using underwater visual census, we studied the use by juvenile reef fishes of various seagrass and mangrove habitats situated differently in relation to the coral reef, on the Caribbean island of Aruba. Additionally, we studied fish assemblages on various coral reefs differing in proximity to seagrass Thalassia testudinum and mangrove Rhizophora mangle habitats at the scale of the whole island. In the seagrass and mangrove habitats, habitat configuration in relation to the reef was related to the composition of the fish assemblage, species richness, fish density and fish size. This was consistent with our expectations related to accessibility of these habitats from the reef, and habitat complexity. Most fish species that use seagrasses and mangroves as juvenile habitats were absent from or showed reduced densities on coral reefs located far (>9 km) from seagrass–mangrove habitats. At a smaller spatial scale...

Evaluation of nursery function of mangroves and seagrass beds for tropical decapods and reef fishes: patterns and underlying mechanisms

Nagelkerken, I.
Fonte: Springer; Netherlands Publicador: Springer; Netherlands
Tipo: Parte de Livro
Publicado em //2009 EN
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Shallow-water tropical coastal habitats, such as mangroves and seagrass beds, have long been associated with high primary and secondary productivity. The ubiquitous presence of juvenile fish and decapods in these systems has led to the hypothesis that they act as nurseries. Earlier studies mainly focused on the faunal community structure of these systems, leaving us with little detailed insight into their potential role as nurseries. Habitats are considered nurseries if their contribution, in terms of production, to the adult population is greater than the average production of all juvenile habitats, measured by the factors density, growth, survival, and/or movement. High food abundance and low predation risk form the most likely factors that contribute to the attractiveness of tropical nursery habitats. Here, the current state of knowledge on nursery function of shallow-water coastal habitats, particularly mangroves and seagrass beds, is reviewed for each of the above-mentioned factors. Most data show that mangroves and/or seagrass beds have high densities of various fish species and some of their food items, and a lower predation risk for fish and decapods due to factors such as low predator abundance, high water turbidity, and complex habitat structure. In contrast...

Mangroves Response to Climate Change: A Review of Recent Findings on Mangrove Extension and Distribution

Godoy,Mario D.P.; Lacerda,Luiz D. de
Fonte: Academia Brasileira de Ciências Publicador: Academia Brasileira de Ciências
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2015 EN
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Mangroves function as a natural coastline protection for erosion and inundation, providing important environmental services. Due to their geographical distribution at the continent-ocean interface, the mangrove habitat may suffer heavy impacts from global climate change, maximized by local human activities occurring in a given coastal region. This review analyzed the literature published over the last 25 years, on the documented response of mangroves to environmental change caused by global climate change, taking into consideration 104 case studies and predictive modeling, worldwide. Most studies appeared after the year 2000, as a response to the 1997 IPCC report. Although many reports showed that the world's mangrove area is decreasing due to direct anthropogenic pressure, several others, however, showed that in a variety of habitats mangroves are expanding as a response to global climate change. Worldwide, pole ward migration is extending the latitudinal limits of mangroves due to warmer winters and decreasing the frequency of extreme low temperatures, whereas in low-lying coastal plains, mangroves are migrating landward due to sea level rise, as demonstrated for the NE Brazilian coast. Taking into consideration climate change alone...

Mangroves Response to Climate Change: A Review of Recent Findings on Mangrove Extension and Distribution

Godoy,Mario D.P.; Lacerda,Luiz D. de
Fonte: Academia Brasileira de Ciências Publicador: Academia Brasileira de Ciências
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2015 EN
Relevância na Pesquisa
27.55%
Mangroves function as a natural coastline protection for erosion and inundation, providing important environmental services. Due to their geographical distribution at the continent-ocean interface, the mangrove habitat may suffer heavy impacts from global climate change, maximized by local human activities occurring in a given coastal region. This review analyzed the literature published over the last 25 years, on the documented response of mangroves to environmental change caused by global climate change, taking into consideration 104 case studies and predictive modeling, worldwide. Most studies appeared after the year 2000, as a response to the 1997 IPCC report. Although many reports showed that the world's mangrove area is decreasing due to direct anthropogenic pressure, several others, however, showed that in a variety of habitats mangroves are expanding as a response to global climate change. Worldwide, pole ward migration is extending the latitudinal limits of mangroves due to warmer winters and decreasing the frequency of extreme low temperatures, whereas in low-lying coastal plains, mangroves are migrating landward due to sea level rise, as demonstrated for the NE Brazilian coast. Taking into consideration climate change alone...

Physiologic sexual maturity of the fiddler crab Uca rapax (Smith, 1870) (Crustacea, Ocypodidae) from two mangroves in Ubatuba, Brazil

Castiglioni,Daniela da Silva; Negreiros-Fransozo,Maria Lucia
Fonte: Instituto de Tecnologia do Paraná - Tecpar Publicador: Instituto de Tecnologia do Paraná - Tecpar
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2006 EN
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The gonad development of Uca rapax was studied to achieve the size at onset of its sexual maturity. Crabs were sampled from April/2001 to March/2002 in the Itamambuca and Ubatumirim mangroves in Ubatuba, São Paulo, Brazil. The specimens were grouped in 10 size classes. Juveniles and adult crabs frequencies were assessed for each class. The size of carapace width in which 50% of males and females were considered mature was 14.8 and 12.1 mm (Itamambuca) and 13.6 and 11.4 mm (Ubatumirim), respectively for males and females. Males matured at higher sizes than females, probably due to a major investment in their somatic growth, while females spend their energy in the reproductive process, saving energy for eggs' production.

Variation in hydraulic conductivity of mangroves: influence of species, salinity, and nitrogen and phosphorus availability

Lovelock, Catherine; Ball, Marilyn; Feller, Ilka C; Engelbrecht, Bettina; Ewe, Mei Ling
Fonte: Blackwell Publishing Ltd Publicador: Blackwell Publishing Ltd
Tipo: Artigo de Revista Científica
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37.09%
We investigated how species identity and variation in salinity and nutrient availability influence the hydraulic conductivity of mangroves. Using a fertilization study of two species in Florida, we found that stem hydraulic conductivity expressed on a lea

Mangroves in Ecuador: An application and comparison of ecosystem service models

Burgess, Paul; Li, Xiangyi; Qin, Siyu
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Masters' project
Publicado em 21/04/2015 EN_US
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Mangroves provide an abundant supply of ecosystem services such as coastal protection, fish nursery, recreation, and carbon sequestration. After a severe loss of mangroves predominately due to shrimp farming from 1969 to 2000, Ecuador realized the importance of mangroves and their related ecosystem services. In response, the government’s interest grew to understand ecosystem services valuation (ESV) models that provide robust valuation for the ecosystem services(ES). Working with the Conservation Strategy Fund (CSF), this report identified and evaluated applicable ESV models, valued and mapped the ecosystem services values of Ecuadorian mangrove with ESV models. This report aims to calculate the value of ecosystem services of mangroves with the existing modeling tools. The following models were initially considered: InVEST, AIRES, MIMES, Co$ting Nature, EcoServ, LUCI, and SolVES. Each model is different, and therefore likely to generate a different valuation of ecosystem services for the same area. In addition, the report compared the variance within models for four different scenarios: status-quo, lose-all, reforestation, full-recovery. Results include both numerical information and highlight the usefulness of each different modeling tool. Based on results and analyses...

A Preliminary Assessment of the Blue Carbon Capacity of Belizean Mangroves with Ecological, Economic, and Policy Perspectives

Chang, Sylvia; Green, Ashley; Kelley, Emma
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Masters' project
Publicado em 24/04/2015 EN_US
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In recent years, mangrove forests have experienced increasing deforestation rates in Belize due to coastal development. Our client, the Belize Ministry of Forestry, Fisheries, and Sustainable Development, wants to determine the potential for Belizean mangrove blue carbon to provide funding opportunities through international financing schemes for the conservation and enhancement of mangroves. Mangrove forests are coastal wetlands along the intertidal zone of tropical and subtropical coastlines. Mangrove, salt marsh, and seagrass ecosystems have significant abilities to sequester and store carbon in their biomass and sediments – the carbon stored in these coastal ecosystems is referred to as “blue carbon.” The impact of mangrove deforestation on carbon sequestration in Belize could be significant, but little is known about how much carbon is stored in Belizean mangroves. The goal of this project was to provide a preliminary assessment of the potential of blue carbon in Belize. This project was broken down into three objectives: ecology, economic, and policy. The goal of the ecology portion of this study was to provide preliminary estimates of the blue carbon stocks of Belize’s mangroves. This required data on the extent of Belizean mangroves...

Ecological Assessment of the Flamingo Mangroves, Guanacaste, Costa Rica

Fedak, Derek; Windstein, Marie
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Masters' project
Publicado em 29/04/2011 EN_US
Relevância na Pesquisa
37.55%
Mangroves are tropical and subtropical ecosystems found in intertidal zones that provide vital ecosystem services including sustenance of commercially important fishery species, improvement of coastal water quality through nutrient cycling and sediment interception, and protection of coastal communities from storm surge and erosion. However, land use conversion and water pollution are threatening these ecosystems and their associated services worldwide. This master’s project conducted an ecological assessment on a mangrove forest adjoining the property of the Flamingo Beach Resort and Spa in Playa Flamingo, located in the Guanacaste province of Costa Rica. The project analyzed vegetation health, water and soil quality, bird species richness, and identified threats to the forest. It also assessed several options for the resort’s development of ecotourism, such as community involvement, the construction of an educational boardwalk, and the creation of a vegetation buffer adjoining the mangroves. The results indicate that the Flamingo Mangroves are generally in a healthy state. Vegetation structure like canopy height, biomass, vegetation importance values, and species distribution compares well with previous ecological studies on mature tidal mangroves. The ecosystem supports 42 resident bird species and likely up to 30 migratory species. However...

Evolution of the Sungei Buloh-Kranji Mangrove Coast, Singapore

Bird, Michael I; Chua, S; Sa Teh, Tiong; Fifield, L Keith; Lai, Joseph
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
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The mangroves from Sungei Buloh Wetland Reserve to Kranji Dam represent the largest intact mangrove forest left on mainland Singapore. Mangroves colonized the area around 6820 BP, as sea level rose following the last glacial maximum and a variable thickness of Holocene sands, muds and peats (generally ∼1 to >3.8 m thick) were deposited over the pre-transgression land surface. An analysis of a time series of photographs covering the period from 1946 to 2001 has revealed major changes in the distribution of mangroves in the area resulting from development-induced changes in the local hydrodynamic regime and clearance for aquaculture. Mangroves covered 117.3 ha in the study area in 1946 and were actively advancing over the coastal mudflats until 1980. Despite the addition of 6.24 ha from mangrove colonization, the total area covered by mangroves was reduced by ∼50% by 1980 due to clearance for aquaculture. Following 1980, a reduction in sediment supply possibly due to the construction of the Kranji Dam, immediately east of the study area, led to the initiation of erosion along much of the coastline, with the mangrove fringe having retreated by up to 50 m in 2001. Establishment of the wetland reserve in 1992 enabled the partial regeneration of mangroves in the area to 86.8 ha...

Economic valuation of mangroves and decision-making in the Pacific

Lal, Padma
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
37.5%
Economists have always argued that only when people bear true economic costs of using natural resources, such as mangroves, that they will have appropriate incentives to use them efficiently and minimize their degradation and losses. More recently, non-economists, too, have started to call for the use of economic valuation information to argue for conservation of mangroves. This paper briefly examines the role economic valuation information can play, at least theoretically, in encouraging conservation of mangroves and increasing efficiency in resource use. In practice, the paper argues that a number of difficulties are likely to be encountered when determining true economic value of mangroves, particularly when small areas of mangroves are involved. A total reliance on economic valuation-based decision-making is questioned, particularly in the light of minimal ecological information often available in small island nations in the Pacific. An alternative decision-making process is proposed in which the relevance of economic valuation-based decision-making is recognized but at a second tier level.

Distribution of fish in seagrass, mangroves and coral reefs: life-stage dependent habitat use in Honduras

Jaxion-Harm,Jessica; Saunders,James; Speight,Martin R
Fonte: Revista de Biología Tropical Publicador: Revista de Biología Tropical
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2012 EN
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37.55%
Many coral reef fish exhibit habitat partitioning throughout their lifetimes. Such patterns are evident in the Caribbean where research has been predominantly conducted in the Eastern region. This work addressed the paucity of data regarding Honduran reef fish distribution in three habitat types (seagrass, mangroves, and coral reefs), by surveying fish on the islands of Utila and Cayos Cochinos off the coast of Honduras (part of the Mesoamerican barrier reef). During July 2nd - Aug 27th 2007 and June 22nd - Aug 17th, 2008, visual surveys (SCUBA and snorkel) were performed in belt transects in different areas: eleven coral reef, six seagrass beds, and six mangroves sites. Juvenile densities and total habitat surface area were used to calculate nursery value of seagrass and mangroves. A total of 113 fish species from 32 families were found during underwater surveys. Multi-dimensional analyses revealed distinct clusters of fish communities in each habitat type by separating fish associated with seagrass beds, mangroves, and coral reefs. Coral reefs showed the highest mean fish species richness and were dominated by adult fish, while juvenile fish characterized seagrass beds and mangrove sites. Habitat use differed widely at the fish species level. Scarus iseri (Striped Parrotfish)...

Photosynthetic efficiency in rhizophoracean mangroves with reference to compartmentalization of photosynthetic pigments

Moorthy,P.; Kathiresan,K.
Fonte: Revista de Biología Tropical Publicador: Revista de Biología Tropical
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/1999 EN
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37.09%
Photosynthetic pigments are localized in protein complexes of chloroplast membranes and their role in photosynthesis has long been established but their efficiency has not been measured in many species. The photosynthetic efficiency of four rhizophoracean mangroves, Rhizophora apiculata, R. mucronata, Bruguiera cylindrica and Ceriops decandra was studied in randomly collected propagules from Pichavaram mangrove forest (southeast coast of India) by estimating the concentration of photosynthetic pigments in protein complexes of the thylakoid membrane. Reaction centre chlorophyll (RC-chl) was maximum in B. cylindrica and minimum in R. mucronata. Of the total amount of chlorophylls, RC-chl constitutes about 50%. The light harvesting complex chlorophyll (LHC-chl) was highest in C. decandra and lowest in R. mucronata. Net photosynthesis was found to be higher in B. cylindrica and lower in R. mucronata with the respective CO2 fixation of 20.52 and 10.83 m mol m-2 s-1. A positive correlation was obtained between RC-chl and net photosynthesis. The stomatal conductance to CO2 influx was also found to be high and low in B. cylindrica and R. mucronata respectively. We refer the chlorophylls present in the reaction centre and light harvesting complex as " membrane bound chlorophyll" and propose to use this as an index for measuring the productivity of mangrove species.