Danielle Mitja

Banco de sementes em cerrado sensu stricto sob queimada e sistemas de cultivo

The objective of this work was to evaluate the burning and cultivation effects on soil seedbanks originally under cerrado vegetation. Two areas under cerrado sensu stricto were sampled, one burned and the other one not burned, as well as areas under tilled crop and pasture. There was no reduction on seedbank, although lower number of species and families and diversity index (Shannon and Simpson) with burning were observed. There was also greater importance value index (IVI) and number of native species, in the non burned area, and of weeds in the burned one. It was observed that the crop area had higher seed density than the pasture and cerrado areas. The species with the highest IVI in the areas were those considered as weeds and forages. The crop area presented lower IVI of native species than the pasture and cerrado areas; besides, it presented diversity indexes (Shannon and Simpson) and native species percentage lower than pasture and cerrado. The cultivation with crop cause higher disturbance in the areas than burning.

Luz e Kno3 na germinação de sementes de Tridax procumbens sob temperatura constante e alternada

There are few studies available on germination of tropical weed species, Tridax procumbens included, despite its importance as a crop weed. This study was carried out at the Laboratory of Plant Biophysics of Embrapa Cerrados, Planaltina, DF, to evaluate the effect of light and KNO3 on T. procumbens seed germination at constant and alternating temperatures. Four sub-samples of 75xa0seeds were submitted to a factorial combination of light (darkness; 12 daily hours of light photoperiod) and substrate moistened with KNO3 solution (0% of KNO3; 0.2% of KNO3) for the assays at 25xa0°C constant and 15xa0oC/35xa0oC alternating temperatures, arranged in a completely randomized experimental design. Seed germination was daily counted based on emission of primary roots, with accumulated germination percentage, germination speed and accumulated germination curve being evaluated. Light contributed to increase germination percentage and speed at constant temperature, while at alternating temperatures, increase of germination percentage and speed occurred with KNO3 application, regardless of the presence or absence of light. The accumulated germination curves at 25xa0oC and 15xa0oC/35xa0oC were adjusted to the logistic model, showing seed germination asynchrony along time.

Caracterização florística de bancos de sementes em sistemas de cultivo lavoura-pastagem

The effect of cultivation systems, tillage and fertilization levels on the floristic composition of seedbanks was evaluated at three cultivation systems (continuous crop, crop-pasture-crop, pasture-crop-pasture), two tillage systems (tillage and no-tillage) and two fertilization levels (corrective and maintenance), and a continuous pasture area under no-tillage and corrective fertilization. Cultivation and tillage system were the most important factors affecting the floristic structure of seedbanks. Besides, corrective fertilization increased the number of families and species in relation to maintenance fertilization.

Pastagens arborizadas no projeto de assentamento benfica, município de Itupiranga, Pará, Brasil

Na microrregiao de Maraba, PA, as pastagens dos agricultores familiares apresentam alta diversidade de arvores e palmeiras que tem papel importante tanto para limitacao da degradacao da biodiversidade quanto para suas utilidades. O trabalho foi realizado em 26 propriedades, onde 62 pastagens foram visitadas junto com o agricultor. Em cada pastagem foram repertoriadas todas as arvores e palmeiras presentes. Setenta e uma especies foram encontradas, pertencentes a 32 familias, das quais nove se destacaram com maior numero de especies: Caesalpiniaceae (11), Mimosaceae (10), Arecaceae (4), Lecythidaceae (4), Bignoniaceae (3), Fabaceae (3), Moraceae (3), Sapotaceae (3) e Sterculiaceae (3); 20 familias apresentaram uma unica especie. Vinte e quatro especies (34% do total) pertenceram as tres familias Leguminosae (Fabaceae, Caesalpiniaceae e Mimosaceae). As especies arborescentes sao conservadas principalmente em razao dos usos diversos na propriedade. Das 21 especies, indicadas para arborizacao de pastagens de agricultores desta e de outras comunidades, nove especies sao particularmente recomendadas pela resistencia ao fogo e para muitos anos de pastagem, pelo fato de ter dois usos ou mais: Caryocar villosum (Aubl.) Pers., Bertholletia excelsa H. B. K., Attalea speciosa Mart. ex Spreng., Oenocarpus distichus Mart., Astrocaryum tucuma Mart., Swartzia flaemingii Raddi, Apeiba tibourbou Aubl., Cenostigma tocantinum Ducke e Spondias mombin L.

Estimating babassu palm density using automatic palm tree detection with very high spatial resolution satellite images

High spatial resolution images as well as image processing and object detection algorithms are recent technologies that aid the study of biodiversity and commercial plantations of forest species. This paper seeks to contribute knowledge regarding the use of these technologies by studying randomly dispersed native palm tree. Here, we analyze the automatic detection of large circular crown (LCC) palm tree using a high spatial resolution panchromatic GeoEye image (0.50xa0m) taken on the area of a community of small agricultural farms in the Brazilian Amazon. We also propose auxiliary methods to estimate the density of the LCC palm tree Attalea speciosa (babassu) based on the detection results. We used the Compt-palm algorithm based on the detection of palm tree shadows in open areas via mathematical morphology techniques and the spatial information was validated using field methods (i.e. structural census and georeferencing). The algorithm recognized individuals in life stages 5 and 6, and the extraction percentage, branching factor and quality percentage factors were used to evaluate its performance. A principal components analysis showed that the structure of the studied species differs from other species. Approximately 96% of the babassu individuals in stage 6 were detected. These individuals had significantly smaller stipes than the undetected ones. In turn, 60% of the stage 5 babassu individuals were detected, showing significantly a different total height and a different number of leaves from the undetected ones. Our calculations regarding resource availability indicate that 6870xa0ha contained 25,015 adult babassu palm tree, with an annual potential productivity of 27.4xa0t of almond oil. The detection of LCC palm tree and the implementation of auxiliary field methods to estimate babassu density is an important first step to monitor this industry resource that is extremely important to the Brazilian economy and thousands of families over a large scale.

CONSERVAÇÃO DAS FLORESTAS DO PROJETO DE ASSENTAMENTO BENFICA, SUDESTE DA AMAZÔNIA

Este trabalho teve como objetivo descrever e analisar a composicao floristica e a estrutura de remanescentes florestais do Projeto de Assentamento Benfica, no municipio de Itupiranga, Para. Foram selecionadas 11 areas de florestas localizadas em diferentes propriedades e com diferentes niveis de perturbacao. No interior de cada area foi inventariada a vegetacao em um transecto de 500 m2, considerando tres estratos: superior, medio e inferior. A vegetacao foi classificada em cinco formas de vida: arvores, arbustos, lianas, palmeiras e herbaceas; e dois grupos funcionais: pioneiras e florestais. Foram encontradas 286 especies, 173 generos e 68 familias. A maioria das especies lenhosas (51%) ocorreu em apenas um estrato. A riqueza de especies correspondeu a 70% da riqueza estimada por Jack-nife de primeira ordem (J1 = 418,45). A porcentagem de especies raras foi alta; 138 especies ocorreram em apenas uma area. Em todos os estratos, as arvores apresentaram maior densidade, exceto no estrato inferior, onde as herbaceas foram mais densas, seguida das arvores. As especies florestais predominaram em todos os estratos. Houve diferenca significativa entre as florestais e pioneiras em todas as formas de vida, em todos os estratos. A analise de componentes principais mostrou heterogeneidade entre os transectos estudados, formando tres grupos que parecem estar relacionados com os diferentes niveis de perturbacoes.

Análise fatorial multivariada aplicada a caracterização de áreas de ocorrência de babaçu (Attalea speciosa Mart. ex Spreng) na bacia do Rio Cocal

O presente artigo possui como objetivo avaliar a distribuicao espacial do babacu na bacia do rio Cocal, nestado de Tocantins. Os dados foram obtidos em levantamento de campo considerando 80 parcelas, nconsiderando os diferentes ambientes presentes na area de estudo. O estudo considerou 16 variaveis nreferentes as caracteristicas do babacu (quantidade de individuos, quantidade de cachos, altura maxima ndo fuste e altura media do fuste) e do meio ambiente (altitude, declividade, area de contribuicao, indice ntopografico, relevo, distância do rio, distância das casas, distância da estrada, declividade do relevo no ncampo, solo, uso do solo e vegetacao). A analise dos dados foi realizada utilizando tecnicas de sistema de ninformacoes geograficas e analise multivariada. O emprego da analise fatorial multipla permitiu classificar nas variaveis ambientais de maior significância para a ocorrencia do babacu e da quantidade de cachos. nO principal fator que controla a distribuicao do babacu e o manejo adotado pelos fazendeiros.

Satellite Images Combined with Field Data Reveal Negative Changes in the Distribution of Babassu Palms after Clearing off Amazonian Forests

When the Amazonian rain forest is cut to create pasture, some of the original vegetal species survive clearing, even expressing their ability to invade agro-systems. It is true of the babassu palm, which can be considered, paradoxically, a natural resource by the “Interstate Movement of Babassu Fruit Breaker Women” or as native weed by land owners-farmers. To manage potential conflict of land uses, we study here the current density of this palm tree in different habitats, based on a combination of field data and remote sensing data. Firstly, we checked that the field survey methodology (i.e., counting free-trunk palm trees over 20u2009cm in circumference) provides density values compatible with those stemming from satellite images interpretation. We can see then that, a PA-Benfica Brazilian territory revealed an average density of the babassu lower in pastures (2.86u2009ind/ha) than in the dense forest (4.72u2009ind/ha) from which they originate and than in fallow land (4.31u2009ind/ha). We analyze in detail density data repartition in three habitats and we discuss results from the literature on the density of this palm tree versus its resilience at different developmental stages after forest clearing, depending on anthropogenic—or not—factors, including solar radiation, fire, weeding, clear cutting, burying fruit, and competition with forage grass. All these results can be exploited for the design of future management plans for the babassu palm and we think that the linked methodology and interdisciplinary approach can be extended to others palms and trees species in similar problematic issues.

Family agriculture and local development: challenges to sustainable economic and ecological community of Palmares II Parauapebas city, Pará state in Brazil

This article aims to analyze the agricultural activities of family farmers and its impact on the environment in Palmares II Settlement, located in the municipality of Parauapebas, PA, and discuss the potential for local development. The economic and ecological sustainability of family farms can be achieved through the empowerment of families settled in farming techniques that conserve natural resources and training for the industrialization of the products being sold in local market.

Agricultura familiar e desenvolvimento local: os desafios para a sustentabilidade econômico-ecológica na comunidade de Palmares II, Parauapebas, PA

This article aims to analyze the agricultural activities of family farmers and its impact on the environment in Palmares II Settlement, located in the municipality of Parauapebas, PA, and discuss the potential for local development. The economic and ecological sustainability of family farms can be achieved through the empowerment of families settled in farming techniques that conserve natural resources and training for the industrialization of the products being sold in local market.