Long-term meteorological analyzes suggest an increase in air temperature and a decrease in rainfall over the Amazon biome. The effect of these climate changes on the forest remains unresolved, because field observations on functional traits are sparse in time and space, and the results from remote sensing analyses are divergent. Then, we analyzed the drought response in a ‘terra firme’ forest fragment in the southwestern Amazonia, during an extreme drought event influenced by ENSO episode (2015/2017), focusing on stem growth, litter production, functional traits and forest canopy dynamics. We use the Moderate Resolution Imaging Spectroradiometer (MODIS), corrected by Multi-Angle Implementation of Atmospheric Correction (MAIAC) to generate the enhanced vegetation index (EVI) and green chromatic coordinate (Gcc) vegetation indices. We monitor stem growth and measure the functional traits of trees in situ, such as the potential at which the plant loses 50% of hydraulic conductivity (P₅₀), turgor loss point (πTLP), hydraulic safety margin (HSM) and isohydricity. Our results suggest that: (a) during the dry season, there is a smooth reduction in EVI values (browning) and an increase in the wet season (greening); (b) in the dry season, leaf flush occurs, when the water table still has a quota at the limit of the root zone; (c) the forest showed moderate resistance to drought, with water as the primary limiting factor, and the thickest trees were the most resistant; and (d) a decline in stem growth post-El-Niño 2015/2016 was observed, suggesting that the persistence of negative rainfall anomalies may be as critical to the forest as the drought episode itself.

O objetivo desse trabalho foi avaliar a influência dos modelos de colonização (“espinha de peixe” e topográfico) nos diferentes estágios sucessionais: Inicial (SS1), Intermediário (SS2) e Avançado (SS3) na Amazônia Legal Brasileira, através de atributos fitossociológicos apoiados por imagens de satélite, e entender as variáveis que afetam os padrões de sucessão florestal e as diferenças existentes entre as variáveis biométricas dentro dos diferentes assentamentos localizados na porção Noroeste do Estado de Rondônia. Para isso foram amostrados 56 transectos de 10 x 250 m em áreas de estágio sucessional avançado, 64 transectos de 10 x 10 m em áreas de estágio sucessional intermediário, e 79 transectos de 2 x 2 m em áreas de estágio sucessional inicial.

O objetivo desse trabalho foi avaliar a influência dos modelos de colonização (“espinha de peixe” e topográfico) nos diferentes estágios sucessionais: Inicial (SS1), Intermediário (SS2) e Avançado (SS3) na Amazônia Legal Brasileira, através de atributos fitossociológicos apoiados por imagens de satélite, e entender as variáveis que afetam os padrões de sucessão florestal e as diferenças existentes entre as variáveis biométricas dentro dos diferentes assentamentos localizados na porção Noroeste do Estado de Rondônia. Para isso foram amostrados 56 transectos de 10 x 250 m em áreas de estágio sucessional avançado, 64 transectos de 10 x 10 m em áreas de estágio sucessional intermediário, e 79 transectos de 2 x 2 m em áreas de estágio sucessional inicial. No modelo de colonização denominado “espinha de peixe”, foram identificadas 23 famílias e 43 espécies - no estágio sucessional inicial; no estágio SS2 foram identificadas 20 famílias e 41espécies; já no estágio sucessional avançado, foram catalogadas 37 famílias com 42 espécies. No modelo de colonização cuja forma é conhecida como topográfico, foram catalogadas no estágio inicial - 32 famílias e 60 espécies; no estágio intermediário - 29 famílias e 54 espécies; e no estágio avançado - 43 famílias e 57 espécies. As famílias mais importantes neste processo de sucessão foram as Fabaceae, Caesalpiniaceae, Lauraceae e Bignoniaceae em ambos os modelos.Palavras-chave: colonização da Amazônia, fitossociologia, sucessão florestal. PHYTOSOCIOLOGICAL ANALYSIS OPEN RAINFOREST COLONIZATION IN DIFFERENT MODELS OF THE AMAZON ABSTRACTThe aim of this study was to evaluate the influence of colonization models (fishbone and topographic) in different successional stages: Initial (SS1), Intermediate (SS2) and Advanced ( SS3) in the Brazilian Amazon, through phytosociological attributes supported by satellite images, and understand the variables that affect the patterns of forest succession and the differences between biometric variables within the different settlements located in the northwestern portion of the state of Rondônia. For that were sampled 56 transects of 10 x 250m in areas of advanced successional stage , 64 transects of 10 x 10 m in areas of intermediate successional stage, and 79 of 2 x 2 m transects in areas of early initial successional stage. In the colonization model called fishbone, were identified 23 families and 43 species - in initial successional stage; in intermediate successional stage were identified 20 families and 41 species already; in advanced successional stage - were cataloged 37 families with 42 species. In the colonization model whose shape is known as topographic, were cataloged on stage SS1, 32 families and 60 species- stage SS2, 29 families and 54 species and stage SS3, 43 families and 57 species. The most important families in the process of succession were the Fabaceae, Caesalpiniaceae, Lauraceae and Bignoniaceae in both models.Keywords: colonization of the Amazon, phytosociology, forest cuccession. DOI: http://dx.doi.org/10.5935/2318-7670.v05n02a07

A região norte do Brasil caracteriza-se pela ausência de complexos de indústria moveleira e de plantações florestais em escala comercial, que ainda está restrita a pequenas áreas. A espécie florestal Paricá [Schizolobium parahyba var. amazonicum (Huber ex. Ducke) Barneby] vem ganhando espaço no cenário nacional, ocupando área de 90.047 hectares em 2015, o que corresponde a 15,3% das florestas plantadas no Brasil. Embora exista incentivos para regularizar o corte desta espécie, a falta de difusão do conhecimento das técnicas silvícolas e de gestão comprometem a produtividade e dificulta seu mapeamento. O presente trabalho teve como objetivo mapear e quantificar as áreas de cultivo de Paricá nomunicipio de Ouro Preto do Oeste, Estado de Rondônia, para os anos de 2009 e 2013. A metodologia baseou-se nas informações orbitais coletadas pela série Landsat 5 (TM) e 8 (OLI), cujas imagens foram processadas em ambiente SIG, utilizando técnicas de processamento digital de imagens. A quantificação mostrou que houve redução de 6,2% da área cultivada no período de 2009 a 2013. Este resultado destaca a necessidade de incentivar o plantio de novas áreas ou a manutenção de áreas existentes. Os produtos orbitais e as técnicas de processamento de dados utilizadas neste trabalho, para fins de identificação e mapeamento das áreas de Paricá, não foram capazes de substituir os trabalhos de campo, devido a alta similaridade na resposta espectral.Palavra-chave: Landsat 8/OLI, processamento de imagens, mapeamento florestal, silvicultura. MAPPING OF PARTICAN PLANTS [Schizolobium parahyba var.amazonicum (HUBER ex. DUCKE) BARNEBY] in THE MUNICIPALITY OF OURO PRETO DO OESTE, RO The northern region of Brazil is characterized by the absence of furniture-industry complexes and forest plantations on a commercial scale still restricted to small areas. The Paricá forest species [Schizolobium parahyba var. amazonicum (Huber ex. Ducke) Barneby] has been gaining ground in the national scenario, occupying an area of 90,047 hectares in 2015, which corresponds to 15.3% of the planted forests in Brazil. Although there are incentives to regularize the cut of this species, the lack of knowledge diffusion of silvicultural techniques and management compromises the productivity, and hinder their mapping. The present work mapped and quantified the paricá growing areas in Ouro Preto do Oeste city, Rondônia state, for the years 2009 and 2013. The methodology was based on the orbital information collected by the Landsat 5 (TM) and 8 (OLI) series, whose images were processed in a GIS environment using digital image processing techniques. The quantification showed that there was a reduction of 6.20% of the cultivated area in the period from 2009 to 2013.This result highlights the need to encourage the planting of new areas or maintenance of existing areas. The orbital products and the data processing techniques used in this work, for the identification and mapping of Paricá areas, were not able to replace the field works, due to the high similarity in the spectral response.Keywords: Landsat 8/OLI, image processing, forest mapping, silviculture. DOI: http://dx.doi.org/10.5935/2318-7670.v05nespa20

Several colonisation projects were implemented in the Brazilian Legal Amazon in the 1970s and 1980s. Among these colonisation projects, the most prominent were those with the “fishbone” and “topographic” models. Within this scope, the settlements known as Anari and Machadinho stand out because they are contiguous areas with different models and structures of occupation and colonisation. The main objective of this work was to evaluate the dynamics of Land-Use and Land-Cover (LULC) in two different colonisation models, implanted in the State of Rondônia in the 1980s. The fishbone and topographic or Disorganised Multidirectional models were implemented in the Anari and Machadinho settlements, respectively. A 36-year time series of Landsat images (1984–2020) was used to evaluate the rates and trends in the LULC process in the different colonisation models. In the analysed models, a rapid loss of primary and secondary forests (anthropized areas) was observed, mainly due to the dynamics of its use, established by the Agriculture/Pasture relation with a heavy dependence on road construction. Understanding these two forms of occupation can help the future programs and guidelines of the Brazilian Legal Amazon and any tropical rainforest across the globe.