64 research outputs found
Estimation of the Distribution of Tabebuia guayacan (Bignoniaceae) Using High-Resolution Remote Sensing Imagery
Species identification and characterization in tropical environments is an emerging field in tropical remote sensing. Significant efforts are currently aimed at the detection of tree species, of levels of forest successional stages, and the extent of liana occurrence at the top of canopies. In this paper we describe our use of high resolution imagery from the Quickbird Satellite to estimate the flowering population of Tabebuia guayacan trees at Barro Colorado Island (BCI), in Panama. The imagery was acquired on 29 April 2002 and 21 March 2004. Spectral Angle Mapping via a One-Class Support Vector machine was used to detect the presence of 422 and 557 flowering tress in the April 2002 and March 2004 imagery. Of these, 273 flowering trees are common to both dates. This study presents a new perspective on the effectiveness of high resolution remote sensing for monitoring a phenological response and its use as a tool for potential conservation and management of natural resources in tropical environments
Payments for ecosystem services in the tropics: a closer look at effectiveness and equity
We undertake a review of academic literature that examines the effectiveness and equity-related performance of PES initiatives targeting biodiversity conservation in tropical and sub-tropical countries. We investigate the key features of such analyses as regards their analytical and methodological approach and we identify emerging lessons from PES practice, leading to a new suggested research agenda. Our results indicate that analyses of PES effectiveness have to date focused on either ecosystem service provision or habitat proxies, with only half of them making explicit assessment of additionality and most describing that payments have been beneficial for land cover and biodiversity. Studies evaluating the impact of PES on livelihoods suggest more negative outcomes, with an uneven treatment of the procedural and distributive considerations of scheme design and payment distribution, and a large heterogeneity of evaluative frameworks. We propose an agenda for future PES research based on the emerging interest in assessing environmental outcomes more rigorously and documenting social impacts in a more comparative and contextually situated form
Relações empíricas entre características dendrométricas da Caatinga brasileira e dados TM Landsat 5
Effects of Habitat Structure and Fragmentation on Diversity and Abundance of Primates in Tropical Deciduous Forests in Bolivia
What evidence exists on the impact of governance type on the conservation effectiveness of forest protected areas? Knowledge base and evidence gaps
Conceptos básicos de cambios en el uso y cobertura de la tierra, ordenamiento territorial y sistemas de información geográficos. Notas de curso
Ilus. A la cabeza del título: Curso Modular No.
Costa Rica's payment for environmental services program: intention, implementation, and impact.
We evaluated the intention, implementation, and impact of Costa Rica's program of payments for environmental services (PSA), which was established in the late 1990s. Payments are given to private landowners who own land in forest areas in recognition of the ecosystem services their land provides. To characterize the distribution of PSA in Costa Rica, we combined remote sensing with geographic information system databases and then used econometrics to explore the impacts of payments on deforestation. Payments were distributed broadly across ecological and socioeconomic gradients, but the 1997-2000 deforestation rate was not significantly lower in areas that received payments. Other successful Costa Rican conservation policies, including those prior to the PSA program, may explain the current reduction in deforestation rates. The PSA program is a major advance in the global institutionalization of ecosystem investments because few, if any, other countries have such a conservation history and because much can be learned from Costa Rica's experiences
Replication Data for: Using visible-near-infrared spectroscopy to classify lichens at a Neotropical Dry Forest
This is the unprocessed spectra of lichens and their bark. In the excel file there are three sheets: i) IDs for species and samples, ii) lichen spectra, and iii) bark spectra. The link between samples and sheets is based on 'ID_sample'
Can terrestrial laser scanners (TLSs) and hemispherical photographs predict tropical dry forest succession with liana abundance?
Tropical dry forests (TDFs) are ecosystems with long drought periods, a mean
temperature of 25 °C, a mean annual precipitation that ranges from 900 to
2000 mm, and that possess a high abundance of deciduous species (trees
and lianas). What remains of the original extent of TDFs in the Americas
remains highly fragmented and at different levels of ecological succession.
It is estimated that one of the main fingerprints left by global
environmental and climate change in tropical environments is an increase in
liana coverage. Lianas are non-structural elements of the forest canopy that
eventually kill their host trees. In this paper we evaluate the use of a
terrestrial laser scanner (TLS) in combination with hemispherical
photographs (HPs) to characterize changes in forest structure as a function
of ecological succession and liana abundance. We deployed a TLS and HP
system in 28 plots throughout secondary forests of different ages and with
different levels of liana abundance. Using a canonical correlation
analysis (CCA), we addressed how the VEGNET, a terrestrial laser scanner, and HPs could predict TDF structure.
Likewise, using univariate analyses of correlations, we show how the liana
abundance could affect the prediction of the forest structure. Our results
suggest that TLSs and HPs can predict the differences in the forest structure at
different successional stages but that these differences disappear as liana
abundance increases. Therefore, in well known ecosystems such as the
tropical dry forest of Costa Rica, these biases of prediction could be
considered as structural effects of liana presence. This research
contributes to the understanding of the potential effects of lianas in
secondary dry forests and highlights the role of TLSs combined with HPs in
monitoring structural changes in secondary TDFs
- …