Land use dynamics under the Bolsa Floresta Program: a case study of the Uatumã Sustainable Development Reserve (Amazonas, Brazil)

Original ArticleThe effectiveness of a program of payment for environmental services (PES) in the Brazilian Amazon was analyzed through an accurate mapping of deforested areas. The Bolsa Floresta Program (BFP) in Amazonas state (Brazil) was chosen as an example of a PES program that aims to compensate farmers for their commitment to zero deforestation of primary forests while opening swiddens only in secondary vegetation areas. However, the official measurement of opened swiddens is not effective since only deforested areas larger than 6.25 ha are mapped, whereas most areas opened for cassava crops are approximately 1 ha in size. The effectiveness of the BFP was evaluated in the Uatumã Sustainable Development Reserve (SDR). We tested a methodology for mapping areas from 0.45 ha upwards that have been opened for cassava swiddens. The years 2006 (before the implementation of the BFP), 2011, 2015 and 2019 were analyzed. The results indicated that 88% of the areas opened for swiddens were between 0.45 and 6.25 ha in size. After the implantation of the BFP, the cumulative total deforested area decreased, and there was a reduction in deforested areas in primary forests. An intensification of swidden cultivation was also observed, which could cause a decline in productivity. The monitoring by land-use zoning showed that the majority of opened areas were located in intensive use zones, following the rules of the SDR management plan. The results show the efforts of local families to fulfill the BFP rulesinfo:eu-repo/semantics/publishedVersio

Formation of babassu in degraded areas by human action in Southeast Pará, Brazil: its importance for recovery of legal reserve areas.

ISEE 2012

Infrared L Band Observations of the Trapezium Cluster: A Census of Circumstellar Disks and Candidate Protostars

We report the results of a sensitive near-infrared JHKL imaging survey of the Trapezium cluster in Orion. We use the JHKL colors to obtain a census of infrared excess stars in the cluster. Of (391) stars brighter than 12th magnitude in the K and L bands, 80 +/- 7% are found to exhibit detectable infrared excess on the J-H, K-L color-color diagram. Examination of a subsample of 285 of these stars with published spectral types yields a slightly higher infrared excess fraction of 85%. We find that 97% of the optical proplyds in the cluster exhibit excess in the JHKL color-color diagram indicating that the most likely origin of the observed infrared excesses is from circumstellar disks. We interpret these results to indicate that the fraction of stars in the cluster with circumstellar disks is between 80-85%. Moreover, we find that the probability of finding an infrared excess/protoplanetary disk around a star is independent of stellar mass over essentially the entire range of the stellar mass function down to the hydrogen burning limit. We identify 78 stars in our sample characterized by K-L colors suggestive of deeply embedded protostellar objects. If even a modest fraction fraction (i.e., ~ 50%) of these objects are protostars, then star formation could be continuing in the molecular ridge at a rate comparable to that which produced the foreground Trapezium cluster.Comment: 33 pages plus 3 separate color figures. For higher resolution color figures and a single file containing the entire paper, figures and tables see http://cfa-www.harvard.edu/~gmuench/thesis/clusters/TRAP/traplband.html Used AASTEX macros v 5.0. Paper will appear in December A

Compact Radio Sources in Orion: New Detections, Time Variability, and Objects in OMC-1S

We present the analysis of four 3.6 cm radio continuum archival observations of Orion obtained using the Very Large Array in its A-configuration, with $0\rlap.{''}3$ angular resolution. The observations were made during the period 1994-1997. In a region of $4' \times 4'$, we detect a total of 77 compact radio sources. Of the total of detected sources, 54 are detected in one or more of the individual observations and 36 of these show time variability (by more than 30%) between the observed epochs. A deep image made from averaging all data shows an additional 23 faint sources, in the range of 0.1 to 0.3 mJy. Of the total of 77 sources, 39 are new centimeter detections. However, only 9 of the 77 sources do not have a previously reported counterpart at near-infrared, optical, or X-ray wavelengths. In particular, we detect three faint sources in the OMC-1S region that may be related to the sources that power the multiple outflows that emanate from this part of the Orion nebula. %We discuss the nature of these sources and its relation with the %near-infrared, optical, and X-ray objects in the region.Comment: 29 pages, 9 figure

Chandra Observations of Variable Embedded X-ray sources in Orion. Paper I: Resolving Orion Trapezium

We used the High Energy Transmission Grating Spectrometer (HETGS) onboard the Chandra X-ray Observatory to perform two observations, separated by three weeks, of the Orion Trapezium region. The zeroth order images on the Advanced CCD Imaging Spectrometer (ACIS) provide spatial resolution of 0.5" and moderate energy resolution. Within a 160"x140" region around the Orion Trapezium we resolve 111 X-ray sources with luminosities between 7x10^{28} ergs/s and 2x10^{32} ergs/s. We do not detect any diffuse emission. Many sources appear much more heavily absorbed, with N_H in the range of 10^22 to 10^23 cm^-2. The main objective of this paper is to study the Orion Trapezium and its close vicinity. Most spectra of the very early type members can be fit with a two-temperature thermal spectrum with a soft component of kT ~ 0.8 keV and a hard component of kT ~ 2 to 3 keV. We discuss these results in the context of stellar wind models. We detect eight additional, mostly variable X-ray sources in the close vicinity of the Trapezium. Five of these X-rays sources are identified with proplyds and we argue that the X-ray emission originates from class I, II and III protostars at the cores of the proplyds.Comment: 12 pages, 3 figures, accepted for publication in The Astrophysical Journa

Spatialisation de la biodiversité en Amazonie brésilienne pour appréhender l'influence de la colonisation des terres et des politiques publiques.

Este artigo propõe uma abordagem de acompanhamento das dinâmicas espaciais da biodiversidade que ocorreram durante os 40 últimos anos na Amazônia brasileira, na comunidade agrícola de Benfica (Estado do Pará). Ela é projetada para estimar « aonde » acontecem as mudanças, « quando » acontecem, de « quanta » superfície se trata e « porque » elas acontecem ? O objectivo apontado é de contribuir para a avaliação do impacto de políticas de colonização sobre estas dinâmicas. Os dados produzidos sobre as disparidades espaciais e sobre os ritmos destas transformações, são uma contribuição que deve enriquecer os conhecimentos sobre a evolução da biodiversidade em frentes pioneiras. No estado atual das pesquisas, a abordagem propõe avaliar a biodiversidade usando uma escala de valores combinando diversos indicadores. Cada um deles contribui para avaliar mudanças que acontecem durante o cultivo das terras florestais. A biodiversidade é depois avaliada em dois níveis : o nível das diferentes formas de exploração dos recursos calculando a medida da biodiversidade ao nível do componente da paisagem (floresta, capoeira, cultivo/pastagem), e ao nível da categoria de ator (do colono, ao pequeno fazendeiro), calculando a medida da biodiversidade da unidade de território que cada um explora preferencialmente. O processo de acompanhamento deste território no tempo é facilmente realizável. De fato ele somente depende da disponibilidade de imagens de satélites. Ainda que esta abordagem seja em validação, ela poderia ser reutilizada em outras regiões florestais antropizadas201