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Forest structure and live aboveground biomass variation along an elevational gradient of tropical Atlantic moist forest (Brazil)

ALVES, Luciana F.; VIEIRA, Simone A.; SCARANELLO, Marcos A.; CAMARGO, Plinio B.; SANTOS, Flavio A. M.; JOLY, Carlos A.; MARTINELLI, Luiz A.
Fonte: ELSEVIER SCIENCE BV Publicador: ELSEVIER SCIENCE BV
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
56.5%
Live aboveground biomass (AGB) is an important source of uncertainty in the carbon balance from the tropical regions in part due scarcity of reliable estimates of live AGB and its variation across landscapes and forest types. Studies of forest structure and biomass stocks of Neotropical forests are biased toward Amazonian and Central American sites. In particular, standardized estimates of aboveground biomass stocks for the Brazilian Atlantic forest are rarely available. Notwithstanding the role of environmental variables that control the distribution and abundance of biomass in tropical lowland forests has been the subject of considerable research, the effect of short, steep elevational gradients on tropical forest structure and carbon dynamics is not well known. In order to evaluate forest structure and live AGB variation along an elevational gradient (0-1100 m a.s.l.) of coastal Atlantic Forest in SE Brazil, we carried out a standard census of woody stems >= 4.8 cm dbh in 13 1-ha permanent plots established on four different sites in 2006-2007. Live AGB ranged from 166.3 Mg ha(-1) (bootstrapped 95% CI: 1444,187.0) to 283.2 Mg ha(-1) (bootstrapped 95% CI: 253.0,325.2) and increased with elevation. We found that local-scale topographic variation associated with elevation influences the distribution of trees >50 cm dbh and total live AGB. Across all elevations...

Differences in throughfall and net precipitation between soybean and transitional tropical forest in the southern Amazon, Brazil

Baese, Frank; Elsenbeer, Helmut; Neill, Christopher; Krusche, Alex V.
Fonte: ELSEVIER SCIENCE BV; AMSTERDAM Publicador: ELSEVIER SCIENCE BV; AMSTERDAM
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
66.32%
The expansion of soybean cultivation into the Amazon in Brazil has potential hydrological effects at local to regional scales. To determine the impacts of soybean agriculture on hydrology, a comparison of net precipitation (throughfall, stemflow) in undisturbed tropical forest and soybean fields on the southern edge of the Amazon Basin in the state of Mato Grosso is needed. This study measured throughfall with troughs and stemflow with collar collectors during two rainy seasons. The results showed that in forest 91.6% of rainfall was collected as throughfall and 0.3% as stemflow, while in soybean fields with two-month old plants, 46.2% of rainfall was collected as throughfall and 9.0% as stemflow. Hence, interception of precipitation in soybean fields was far greater than in intact forests. Differences in throughfall, stemflow and net precipitation were found to be mainly associated with differences in plant structure and stem density in transitional forest and soybean cropland. Because rainfall interception in soybean fields is higher than previously believed and because both the area of cropland and the frequency of crop cycles (double cropping) are increasing rapidly, interception needs to be reconsidered in regional water balance models when consequences of land cover changes are analyzed in the Amazon soybean frontier region. Based on the continued expansion of soybean fields across the landscape and the finding that net precipitation is lower in soy agriculture...

Soil seed banks in tropical forest fragments with different disturbance histories in southeastern Brazil

Martins, Andreza Maria; Engel, Vera Lex
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 165-174
ENG
Relevância na Pesquisa
66.47%
Soil seed banks are considered an important mechanism for natural regeneration in tropical forest ecosystems. This paper investigated the soil seed bank in two semideciduous seasonal tropical forest fragments with different disturbance histories in Botucatu, southeastern Brazil. In each study site, 40 superficial soil samples (30 cm × 30 cm × 5 cm) were taken at the end of both the dry and rainy seasons. The seeds were estimated by the germination method. Average soil seed density was 588.6 and 800.3 seeds m-2, respectively, for site 1 (less disturbed) and site 2 (more disturbed). Seed density and diversity (H′) were significantly higher in site 2 in both seasons. Non-woody taxa predominated in both fragments, but pioneer tree species were better represented in the less disturbed forest. Both ecosystems have a potential for regeneration from soil seed banks, but this potential is higher in the less disturbed site. Low richness and density of pioneer tree species in the seed bank indicate that the ecosystem has lost its resilience. The seed bank is not as important in these ecosystems as in other forests. Results indicate that management strategies to restore these forests should take into account the possibility of recovering soil seed bank processes and dynamics. © 2007 Elsevier B.V. All rights reserved.

Forest structure and live aboveground biomass variation along an elevational gradient of tropical Atlantic moist forest (Brazil)

ALVES, Luciana F.; VIEIRA, Simone A.; SCARANELLO, Marcos A.; CAMARGO, Plinio B.; SANTOS, Flavio A. M.; JOLY, Carlos A.; MARTINELLI, Luiz A.
Fonte: ELSEVIER SCIENCE BV Publicador: ELSEVIER SCIENCE BV
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
56.5%
Live aboveground biomass (AGB) is an important source of uncertainty in the carbon balance from the tropical regions in part due scarcity of reliable estimates of live AGB and its variation across landscapes and forest types. Studies of forest structure and biomass stocks of Neotropical forests are biased toward Amazonian and Central American sites. In particular, standardized estimates of aboveground biomass stocks for the Brazilian Atlantic forest are rarely available. Notwithstanding the role of environmental variables that control the distribution and abundance of biomass in tropical lowland forests has been the subject of considerable research, the effect of short, steep elevational gradients on tropical forest structure and carbon dynamics is not well known. In order to evaluate forest structure and live AGB variation along an elevational gradient (0-1100 m a.s.l.) of coastal Atlantic Forest in SE Brazil, we carried out a standard census of woody stems >= 4.8 cm dbh in 13 1-ha permanent plots established on four different sites in 2006-2007. Live AGB ranged from 166.3 Mg ha(-1) (bootstrapped 95% CI: 1444,187.0) to 283.2 Mg ha(-1) (bootstrapped 95% CI: 253.0,325.2) and increased with elevation. We found that local-scale topographic variation associated with elevation influences the distribution of trees >50 cm dbh and total live AGB. Across all elevations...

Maximum leaf photosynthetic light response for three species in a transitional tropical forest in Southern Amazonia

Miranda,Eduardo J.; Priante Filho,Nicolau; Priante,Pedro C.; Campelo Jr.,José H.; Suli,George S.; Fritzen,Clóvis L.; Nogueira,José de S.; Vourlitis,George L.
Fonte: Departamento de Engenharia Agrícola - UFCG Publicador: Departamento de Engenharia Agrícola - UFCG
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2004 EN
Relevância na Pesquisa
66.32%
Measurements of CO2 and water vapor flux using eddy covariance are being made from a 40 m tower located in a transitional tropical forest near Sinop Mato Grosso. As complementary information to this study, the photosynthetic light response curves of three species located near the tower were measured at different heights in the forest canopy and light conditions with the objective of understanding seasonal and spatial (height in the forest canopy and gap or shade located plants) trends in the photosynthetic light response. The measurements were made in a canopy emergent tree (30 m tall) identified as Brosimum lactescens, and in two relatively short plants (0.6 to 1.6 m height) identified as Quiina pteridophylla and Diniszia excelsa located in different light condition. Measurements were made from the end of 2000 dry season to January 2002. These data suggest that species response to seasonal variations in rainfall are variable. In addition, shade plants have a higher quantum yield (A) and a lower estimated gross photosynthesis at saturating (photosynthetic active radiation - PAR) (Amax) than gap plants, presumably because shade plants are adapted to lower average light levels.

Seedling growth of understorey species of a Southeast Brazilian tropical forest

Válio,Ivany Ferraz Marques
Fonte: Instituto de Tecnologia do Paraná - Tecpar Publicador: Instituto de Tecnologia do Paraná - Tecpar
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2003 EN
Relevância na Pesquisa
66.24%
Thirteen understorey species of a mesophyllous tropical forest were studied under two different photosynthetic photon flux densities (PPFD). Seedlings were grown in the glasshouse under 51% and 2.6% solar PPFD. Growth of the seedlings was evaluated by 1-) total height; 2-) leaf number; 3-) leaf dry mass;4-) stem dry mass; 5-) root dry mass; 6-) stem length/mass; 7-)shoot/root mass; 8-) percent allocation to leaf, stem and roots. For most of the parameters recorded, low PPFD drastically reduced growth. It seemed that the strategy of these understorey species was a reduction of growth under low PPFD saving energy for survival.

Patterns of Water and Heat Flux Across a Biome Gradient From Tropical Forest to Savanna in Brazil

Wofsy, Steven; Maia, Jair F.; Aguiar, Renata G.; von Randow, Celso; Freitas, Helber C.; Kruijt, Bart; Nobre, Antonio D.; Cardoso, Fernando L.; Nogueira, José S.; Vourlitis, George; Artaxo, P.; Borma, Laura S.; Coupe, Natalia R.; Saleska, Scott R.; Goulde
Fonte: American Geophysical Union Publicador: American Geophysical Union
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
66.42%
We investigated the seasonal patterns of water vapor and sensible heat flux along a tropical biome gradient from forest to savanna. We analyzed data from a network of flux towers in Brazil that were operated within the Large-Scale Biosphere-Atmosphere Experiment in Amazonia (LBA). These tower sites included tropical humid and semideciduous forest, transitional forest, floodplain (with physiognomies of cerrado), and cerrado sensu stricto. The mean annual sensible heat flux at all sites ranged from 20 to 38 Wm−2, and was generally reduced in the wet season and increased in the late dry season, coincident with seasonal variations of net radiation and soil moisture. The sites were easily divisible into two functional groups based on the seasonality of evaporation: tropical forest and savanna. At sites with an annual precipitation above 1900 mm and a dry season length less than 4 months (Manaus, Santarem and Rondonia), evaporation rates increased in the dry season, coincident with increased radiation. Evaporation rates were as high as 4.0 mm d−1 in these evergreen or semidecidous forests. In contrast, ecosystems with precipitation less than 1700 mm and a longer dry season (Mato Grosso, Tocantins and São Paulo) showed clear evidence of reduced evaporation in the dry season. Evaporation rates were as low as 2.5 mm d−1 in the transitional forests and 1 mm d−1 in the cerrado. The controls on evapotranspiration seasonality changed along the biome gradient...

Global tropical forest cover change assessment with medium spatial stellite imagery using a systematic sample grid - data, methods and first results.

BEUCHLE, R.; EVA, H. D.; MIRANDA, E. E. de; HOLLER, W. A.; OSHIRO, O. T.; ACHARD, F.
Fonte: In: SIMPÓSIO BRASILEIRO DE SENSORIAMENTO REMOTO, 15., 2011, Curitiba. Anais... São José dos Campos: INPE, 2011. Publicador: In: SIMPÓSIO BRASILEIRO DE SENSORIAMENTO REMOTO, 15., 2011, Curitiba. Anais... São José dos Campos: INPE, 2011.
Tipo: Artigo em anais de congresso (ALICE) Formato: p. 2981-2988.
PT_BR
Relevância na Pesquisa
66.37%
At the Joint Research Centre (JRC) of the European Commission, a methodology has been developed to monitor the pan-tropical forest cover with remote sensing data for the years 1990-2000-2005 in Latin America, Southeast Asia and Africa on the basis of over 4000 sample units sample units with a dimension of 20 km by 20 km located at every full latitude and longitude degree confluence. From the Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper (ETM) instruments, images with low cloud impact from the epochs around the years 1990, 2000 and 2005 were selected and subsets covering the sample units were cut-out, pre-processed, segmented and classified in five different land cover classes in order to build global and regional statistics on tropical forest cover change. The data was validated in three steps, internal correction of wrongly classified objects, external (national or regional) expert validation and internal harmonization of the data. In this paper, the data collection and the workflow of the forest cover change assessment for the epochs 1990 and 2000 is presented. Parts of the results for the Brazilian Amazon have been validated by comparing with interpretations of corresponding samples carried out by the Instituto Nacional de Pesquisas Espaciais (INPE)...

Ghana - High Forest Biodiversity Conservation Project

Mastri, Lawrence
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Relevância na Pesquisa
56.49%
The Global Environment Facility (GEF) supported High Forest Biodiversity Conservation Project intended to increase the ecological security of globally significant biological resources, especially within threatened tropical moist forest ecosystems. The project aimed to establish effective systems for the protection of 30 Globally Significant Biodiversity Areas (GSBAs) in all tropical forest biomes in Ghana in four regions within the high forest zone - namely, Ashanti, Eastern, Central, and Western regions. The project focused on communities living at the periphery of these GSBAs.

Biodiversity Conservation in the Context of Tropical Forest Management

Putz, Francis E.; Redford, Kent H.; Robinson, John G.; Fimbel, Robert; Blate, Geoffrey M.
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
EN_US
Relevância na Pesquisa
56.58%
This paper disaggregates the term "biodiversity" into components (landscapes, ecosystems, communities, species/populations, and genes) and attributes (structure, composition, and function). It then disaggrgates "logging" by detailing the vast range of activities subsumed under the term including variation of logging intensities, logging methods, collateral damage, and silvicultural approaches. Using the richness present in both terms, a framework for considering the impacts of logging and other forest management activities on the various components and attributes of biodiversity is presented. This framework is, in turn, used to evaluate the extensive literature covering different studies of logging in tropical forests. This paper does not conclude with uncritical support for sustainable forest managmement of timber as a conservation strategy. Such an endorsement is unwarranted given widespread illegal logging in the tropics, widespread frontier logging and logging of areas of high priority for biodiversity protection...

Community Forest Management and REDD+

International Forestry Resources and Institutions Research Network
Fonte: Washington, DC: Program on Forests (PROFOR) Publicador: Washington, DC: Program on Forests (PROFOR)
EN_US
Relevância na Pesquisa
56.48%
The urgent need to limit anthropogenic carbon emissions has led to a global initiative to Reduce Emissions from Deforestation and forest Degradation (REDD+). But designing national architectures for REDD+ that integrate local actions on forests with national-level outcomes and do so effectively, efficiently, and equitably continues to be challenging. One option to facilitate the design and implementation of REDD+ is to learn from the experience of other programs that have historically been successful in achieving sustainable tropical forest management, such as community forest management (CFM). Lessons about the factors that contribute to CFM success will be useful in designing REDD+ programs. REDD+ may also benefit from harnessing the capital developed by CFM. Of course, REDD+ and CFM represent both opportunities and challenges for each other. Identifying how CFM can contribute to REDD+ goals, and the potential benefits and risks in using CFM to achieve REDD+ implementation requires careful analysis of available evidence because the two sets of interventions do not have a complete overlap in terms of their objectives and mechanisms.

Avian Habitat Preference in Tropical Forest Restoration in Southern Costa Rica

Reid, J. Leighton; Harris, J. Berton C.; Zahawi, Rakan A.
Fonte: Association of Tropical Biology Publicador: Association of Tropical Biology
Tipo: Artigo de Revista Científica
Publicado em //2012 EN
Relevância na Pesquisa
66.42%
An important question for tropical forest restoration is whether degraded lands can be actively managed to attract birds. We censused birds and measured vegetation structure at 27 stations in young (6–9‐yr old) actively and passively restored pasture and old growth forest at Las Cruces Biological Station in southern Costa Rica. During 481 10‐min point counts, we detected a high diversity—186 species— of birds using the restoration area. Surprisingly, species richness and detection frequency did not differ among habitats, and proportional similarity of bird assemblages to old growth forest did not differ between restoration treatments. Bird detection frequency was instead explained by exotic grass cover and understory stem density—vegetation structures that were not strongly impacted by active restoration. The similarity of bird assemblages in actively and passively restored forest may be attributed to differential habitat preferences within and among feeding guilds, low structural contrast between treatments, or the effect of nucleation from actively restored plots into passively restored areas. Rapid recovery of vegetation in this recently restored site is likely due to its proximity to old growth forest and the lack of barriers to effective seed dispersal. Previous restoration studies in highly binary environments (i.e....

Forest Loss Impac on River Flow Regimes of the Singkarak - Ombilin River Basin, West Sumatra, Indonesia

Jeanes, Kevin Wayne
Fonte: Universidade Nacional da Austrália Publicador: Universidade Nacional da Austrália
Tipo: Thesis (PhD)
EN
Relevância na Pesquisa
56.61%
The impact of forest loss on catchment watershed functions has been the subject of scientific and public debate since the 1840’s in the temperate world and since the 1920’s in the tropical world. The thesis seeks to explore this debate and the impact of tropical native forest loss and soil degradation on catchment hydrologic response and the related river basin hydrological regimes. Evidence on these hydrological topics has been sought from a literature review, wet tropical case study and a combined bio-physical science, social survey and numerical analysis and modelling approach. The thesis identifies the impact of forest loss on aquifer recharge, low flows, flood patterns and flow seasonality, and the existence of the soil degradation-induced ‘infiltration trade-off’ effect (Bruijnzeel, 1988 ; Bruijnzeel, 1989), these being the main disputed issues of the science and debate. The stakeholders in the debate are identified to have a mismatch of perceptions stemming from their science or observations having been derived from sites with different hydroclimatic and soil conditions and different spatial and temporal scales. The rift exists between: ‘mainstream’ predominantly temperate hydrologists who had focussed on short-term and small-scale research studies on non-degraded soils; and ‘soil-focused’ tropical hydrologists and the tropical public...

Mapping, quantifying and assessing the effects of different social factors underlying recent trends in tropical forest cover change and biocultural conservation a case study on the ancestral lands of Tsimane' Amerindians (Bolivian Amazon) /

Paneque-Gálvez, Jaime
Fonte: [Barcelona] : Universitat Autònoma de Barcelona, Publicador: [Barcelona] : Universitat Autònoma de Barcelona,
Tipo: Tesis i dissertacions electròniques; info:eu-repo/semantics/doctoralThesis Formato: application/pdf
Publicado em //2012 ENG; ENG
Relevância na Pesquisa
56.56%
Los bosques tropicales juegan un papel clave en la conservación de la biodiversidad, la regulación hidrológica, el clima regional y global, y son vitales para el sustento de sus habitantes. Sin embargo, la extensión actual y la intensidad de los cambios de usos del suelo y de cobertura en los bosques tropicales están propiciando su pérdida, fragmentación y degradación a un ritmo alarmante. Por lo tanto, comprender los factores subyacentes a la pérdida y al empobrecimiento de los bosques tropicales es un asunto de enorme importancia para que se puedan implementar políticas de conservación más eficaces. En esta tesis doctoral llevo a cabo un estudio de caso sobre las tierras ancestrales de indígenas Tsimane', una sociedad indígena de cazadores-recolectores y agricultores nativos de la Amazonía boliviana, con los objetivos principales de cartografiar, cuantificar y evaluar los efectos de diferentes factores sociales que subyacen a las tendencias recientes en el cambio de la cubierta forestal y los niveles de conservación biológica y cultural. En concreto, dedico el primer capítulo de investigación a elaborar un enfoque eficaz para mapear con precisión clases generales de usos del suelo/cobertura, que incluyen tanto los bosques en regeneración como los maduros...

Land use, food production, and the future of tropical forest species in Ghana

Phalan, Benjamin Timothy
Fonte: University of Cambridge; Department of Zoology Publicador: University of Cambridge; Department of Zoology
Tipo: Thesis; doctoral; PhD
EN
Relevância na Pesquisa
66.39%
Agriculture is arguably the greatest threat to tropical forest species. Conservation scientists disagree over the relative importance of two opposing strategies for minimising this threat: enhancing on-farm biodiversity, through wildlife-friendly farming practices, or sparing land for nature by using high-yielding farming methods on the smallest possible area to reduce the need to convert natural habitats. Previous theoretical work shows that understanding the relationship between population density and yield for individual species is crucial for determining whether one of these strategies, or a mixed strategy, will maximise their populations for a given food production target. In this thesis, I aim to identify what land-use strategy will permit increases in food production with least impact on species in the forest zone of Ghana. Farm-fallow mosaic landscapes with shifting cultivation and native canopy trees produced only around 15% as much food energy per hectare as the highest-yielding oil palm plantations. In farm mosaics where perennial tree crops dominate, food production and profits were higher, but did not reach those of oil palm plantations. I surveyed birds and trees in forest, farm mosaic, and oil palm plantation, and combined these data with information on yields to assess the likely consequences of plausible future scenarios of land-use change. My results provide evidence of a strong trade-off between wildlife value and agricultural yield. Species richness was high in low-yielding farming systems...

Gabon’s Overlooked Carbon: A tropical forest study of coarse woody debris

Carlson, Ben
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Masters' project
Publicado em 26/04/2013 EN_US
Relevância na Pesquisa
66.39%
Large dead trees and other large forest detritus (collectively known as coarse woody debris, or CWD) play an important role in the global carbon cycle. In tropical systems, CWD stocks (necromass) have been found to constitute 5% to 33% of total biomass. Despite harboring the second largest rain forest on earth, in Central Africa there have been virtually no studies of coarse woody debris. In this study 15 plots were established in 5 forest zones in Gabon, Africa to measure CWD stocks and potential environmental and land-use determinants of CWD. Necromass of CWD was found to be positively correlated with precipitation and was higher in logged forests than in primary forests. Extrapolated to the entire country, Gabon is estimated to contain carbon CWD content of between 0.34 Pg C to 0.72 Pg C (14 Mg C ha-1 to 30.1 Mg C ha-1). The results of this study will help improve tropical forest carbon flux estimates.

Phenotypic plasticity of the basidiomata of Thelephora sp. (Thelephoraceae) in tropical forest habitats

Ramírez-López,Itzel; Villegas Ríos,Margarita; Cano-Santana,Zenón
Fonte: Revista de Biología Tropical Publicador: Revista de Biología Tropical
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2013 EN
Relevância na Pesquisa
66.35%
Phenotypic plasticity in macroscopic fungi has been poorly studied in comparison to plants or animals and only general aspects of these changes have been described. In this work, the phenotypic variation in the basidiomata of Thelephora sp. (Thelephoraceae) was examined, as well as some aspects of its ecology and habitat, using 24 specimens collected in the tropical forests of the Chamela Biological Station, Jalisco, Mexico. Our observations showed that this taxon has clavarioid basidiomata that can become resupinate during development and growth if they are in contact with rocks, litter or live plants, establishing in the latter only an epiphytic relationship. This tropical species may form groups of up to 139 basidiomata over an area of 32.2m2, and in both types of vegetation (tropical sub-evergreen and deciduous forest) were primarily located on steep (>20°) South-facing slopes. It is found under closed canopy in both tropical forests, but its presence in sub-evergreen forests is greater than expected.

Population dynamics of the bat Dermanura tolteca (Chiroptera: Phyllostomidae) in a tropical forest in Mexico

García-García,José Luís; Santos-Moreno,Antonio; Rodríguez-Alamilla,Arisbe
Fonte: Revista de Biología Tropical Publicador: Revista de Biología Tropical
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2010 EN
Relevância na Pesquisa
66.31%
The fruit-eating bat, Dermanura tolteca, has a broad geographic distribution in Mexico and it is a very important seed dispersal of Neotropical plants. Nonetheless, information on the biology of this bat species is scarce, especially with regard to demography. We studied some ecological aspects and population dynamics of D. tolteca from Southeastern Mexican State of Oaxaca. The study was conducted in a perennial tropical forest, over a period of 80 nights, a sampling effort of 73 200 mist-net-hour, from May 2006 to August 2007. A total of 176 specimens were captured, 98 females and 78 males. Population size was estimated in 237 individuals in the study area, with a greater number during rainy season. The population density of this bat, in its range of distribution in Mexico is low compared to other nose-leaf bats. Captures were correlated with monthly precipitation, and this result may be linked to food resources abundance in tropical and subtropical areas. The reproductive pattern was bimodal polyestrous, with birth periods between August-September and April-June. Greater body mass was observed in females than males. The male-female ratio and age-related demographics were similar to other noseleaf bats. The biological characteristics of D. tolteca are typical of nose-leaf bats of the family Phyllostomidae. Rev. Biol. Trop. 58 (4): 1323-1334. Epub 2010 December 01.

Effect of saline solutions and salt stress on seed germination of some tropical forest tree species

Agboola,D. A.
Fonte: Revista de Biología Tropical Publicador: Revista de Biología Tropical
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/1998 EN
Relevância na Pesquisa
66.24%
The effect of several saline solutions (as given by six salts) and salt stress (as given by 0.1 - 2m sodium chloride solutions) on the germination of seeds of six selected tropical forest tree species was investigated. Saline solutions (0.2m) of the six salts used had highly significant effects on seed germination in most of the tree species. Sodium sulphate (Na2So4) permitted germination in the seeds of Ceiba pentandra and Tectona grandis presoaked in its 0.2m solution for 36 and 48h respectively. The Zinc sulphate (ZnSO4) solution enhanced the germination of seeds of Terminalia ivorensis and Terminalia superba. Solution of Potassium per Manganate favoured the germination of seeds of T. grandis, T. ivorensis and T. superba. In general, increase in molar concentration of NaCl adversely affected the germination rate of seeds. Sees of the two Terminalia species could withstand NaCl salt stress. Seeds of T. grandis have high ability to withstand salt stress comparatively.

Biogeography of the areas and Canthonini (Coleoptera: Scarabaeidae) of dry tropical forest in Mesoamerica and Colombia

Padilla-Gil,Dora Nancy; Halffter,Gonzalo
Fonte: Instituto de Ecología A.C. Publicador: Instituto de Ecología A.C.
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2007 EN
Relevância na Pesquisa
66.39%
This biogeographical analysis examines the historical, geological, climatic and ecological processes that have influenced the formation of the dry tropical forests (DTF) of Mesoamerica and Colombia, areas that are the setting for multiple biogeographical stories that in this case are illustrated by the patterns and evolutionary processes of Canthonini. In this study we test the hypothesis that the Canthonini fauna of dry tropical forests has a South American affinity. To this end, we compare extant species from a tract of dry tropical forest in Mexico, a second enclave in Costa Rica, four from the Caribbean region of Colombia and finally one from the north of Tolima in the Upper Magdalena River Valley, Colombia. The geomorphological characteristics of the enclaves of DTF are also compared, as are the geographical distribution and taxonomic affinities of each of the species found in these dry tropical forests. The biogeographical, historical and geological aspects of the enclaves were evaluated using a Parsimony Analysis of Endemicity (PAE), with two tropical rain forests as the outgroup: Leticia (Amazonas, Colombia) and Los Tuxtlas (Veracruz, Mexico). This study reveals the origin and distribution of Neotropical dry forests in the Pleistocene...