Luís Cláudio de Oliveira

Rapid tree carbon stock recovery in managed Amazonian forests

While around 20% of the Amazonian forest has been cleared for pastures and agriculture, one fourth of the remaining forest is dedicated to wood production. Most of these production forests have been or will be selectively harvested for commercial timber, but recent studies show that even soon after logging, harvested stands retain much of their tree-biomass carbon and biodiversity. Comparing species richness of various animal taxa among logged and unlogged forests across the tropics, Burivalova et al. found that despite some variability among taxa, biodiversity loss was generally explained by logging intensity (the number of trees extracted). Here, we use a network of 79 permanent sample plots (376 ha total) located at 10 sites across the Amazon Basin to assess the main drivers of time-to-recovery of post-logging tree carbon (Table S1). Recovery time is of direct relevance to policies governing management practices (i.e., allowable volumes cut and cutting cycle lengths), and indirectly to forest-based climate change mitigation interventions.While around 20% of the Amazonian forest has been cleared for pastures and agriculture, one fourth of the remaining forest is dedicated to wood production [1] . Most of these production forests have been or will be selectively harvested for commercial timber, but recent studies show that even soon after logging, harvested stands retain much of their tree-biomass carbon and biodiversity [2,3] . Comparing species richness of various animal taxa among logged and unlogged forests across the tropics, Burivalova et al. [4] found that despite some variability among taxa, biodiversity loss was generally explained by logging intensity (the number of trees extracted). Here, we use a network of 79 permanent sample plots (376 ha total) located at 10 sites across the Amazon Basin [5] to assess the main drivers of time-to-recovery of post-logging tree carbon ( Table S1 ). Recovery time is of direct relevance to policies governing management practices (i.e., allowable volumes cut and cutting cycle lengths), and indirectly to forest-based climate change mitigation interventions.

Cultivo de espécies alimentares em quintais urbanos de Rio Branco, Acre, Brasil

(Cultivation of food species in urban gardens in Rio Branco, Acre, Brazil). Home gardens are urban spaces that guarantee human interaction with elements from the natural word, and the cultivation of food plants in these gardens can be important in complementing the diet of city residents. Th e goal of this work was to make an assessment of the eatable food plants grown in home gardens in the city of Rio Branco. In 2009 and 2010, on-site interviews were carried out using a questionnaire, which recorded the plant species of each kind of food, area of the gardens and the socioeconomic factors, for 132 gardens in Rio Branco. Th e neighborhoods selected for this study, Aeroporto Velho, Novo Horizonte and Placas, were located in the outskirts of the city. Seventy-seven food plants were recorded, which belong to 34 plant families. Of these, Solanaceae (12.6%) and Myrtaceae (11.3%) with 62.0% of the kinds of fruits and 38.0% of the vegetables. Of the total number of plants recorded, 82.3% were exotic, 34.1% were medicinal and 18.9% were ornamental. No signifi cant statistical association was detected between species and socioeconomic factors. Nonparametric analysis of variance indicated signifi cant diff erences between neighborhoods, showing that Placas had a higher quantity of species. Th e quantity of species correlated positively in the home gardens. Food plants cultivated in Rio Branco gardens conserve agrobiodiversity and aid in the health and well-being of the residents by improving the landscape, ambience and leisure space of the city.

Reactive Oxygen Species and Cellular Interactions Between Mycosphaerella fijiensis and Banana

Globally, the banana plant (Musa spp) is the fourth most important crop after rice, wheat and corn (based on production in tons). It is cultivated in more than 100 tropical and subtropical countries, mainly by small producers and is a fundamental food source for millions of people. Black leaf streak disease (BLSD), caused by Mycosphaerella fijiensis Morelet (sexual phase) or Paracercospora fijiensis (Morelet) Deighton (asexual phase), is the main disease affecting the world’s banana culture. This disease has a wide geographical distribution accounting for losses exceeding 50% of global banana production. We conducted a comparative histocytological study on the kinetics of the infection process using three banana genotypes with phenotypes that differ in resistance to BLSD: Grand Naine (Susceptible), Pisang Madu (Partially Resistant) and Calcutta 4 (Resistant). Experiments were conducted under controlled conditions with the objective of characterizing the cellular interaction processes between M. fijiensis and Musa acuminata. Conidia germination occurred 24 hours after inoculation. Germination rates were high (97%) and there were no significant differences between the three genotypes (P > 0.147). The Peroxidase enzyme and H2O2 were associated with a hypersensitivity-like reaction in the resistant genotype Calcutta 4, indicating a possible role of the enzyme or its product as defense mechanisms against M. fijiensis in banana plants.

Durabilidade de madeira de eucalipto citriodora (Corymbia citriodora (Hook.) K.D. Hill & L.A.S. Johnson) tratada com CCA em ambiente amazônico

The intense economic exploration has caused a decrease of the original stock of Amazon woody species, including those of high natural durability used in soil contact. The lack of those species results in increased price that makes economically unfeasible of the use, an alternative is the replacement by planted species of fast-growing treated with preservatives. Another advantage of to use species planted to replace the traditional species is environmental, because this will reduce the exploratory pressure on these species. The objective of this study is to evaluate the degree of biological degradation of eucalyptus citriodora wood (Corymbia citriodora (Hook.) K.D. Hill & L.A.S. Johnson) treated with chromated copper arsenate (CCA) under vacuum and pressure process and exposed in field experiment in Rio Branco-AC. The experiment was implemented in May 2005 with cuttings treated with CCA and not treated. The variables evaluated were: 1) degradation by fungi, 2) degradation by termites, and 3) region or part of the piece affected. After the 3rd evaluation (47 months of test), 100% of the specimens without treated were classified with the maximum degree of degradation and, in contrast, 100% of the specimens treated with CCA, after 60 months of test, were classified with the minimum degree of degradation. The parties of the pieces without treatment with the higher and the lesser degrees of degradation were, respectively, the inferior head and the aerial part above 10 cm of soil. The degradation caused by fungi was slightly lower than that of termites. The field experiment has shown that is technically feasible the use of eucalyptus wood to replace the traditional species of the Amazon.

Manejo da estrutura diamétrica remanescente de florestas tropicais

O incremento de uma floresta sob uma exploracao madeireira depende nao apenas do ritmo de crescimento das especies como tambem da distribuicao diametrica remanescente que devera permanecer pos corte. O trabalho avaliou, mediante simulacao, a estrutura diametrica remanescente de um talhao de floresta ombrofila no estado do Amazonas, visando a garantia de ter incremento que recupere a extracao. A simulacao do crescimento da floresta pos-exploracao, respeitando a taxa calculada e a estrutura, permitiram um incremento que pode recuperar o volume comercial inicial durante o ciclo considerado (25 anos). Observouse nas simulacoes que a remocao de todo volume comercial disponivel das especies estudadas impede a recuperacao da floresta no ciclo considerado. Observou-se tambem que as classes diametricas comerciais remanescentes (acima do centro de classe de 45 cm) sao responsaveis por 81 % do incremento necessario para recuperacao do volume comercial removido. Identificou-se um ponto otimo de classe diâmetro a ser mantida na floresta, acima do qual o retorno do volume comercial e nulo. O ponto crucial da recuperacao do volume extraido e o potencial de incremento da estrutura que deve permanecer no compartimento.

Plantas ornamentais em quintais urbanos de Rio Branco, Brasil

Ornamental plants are important in the culture and welfare of city dwellers in the Amazon. This study aimed to perform a characterization of species of ornamental use in urban backyards of Rio Branco and relation with social aspects of the respondents. Semi-structured interviews featuring ornamental species along with analysis of social aspects of urban respondents of the 132 backyards in Rio Branco, Acre, Amazon between 2009 and 2011. Selected for this study were neighborhoods Aeroporto Velho, Placas and Novo Horizonte, located on the periphery of the municipality. Were detected 140 ornamental species belonging to 49 different botanical families, especially Euphorbiaceae (7%), Arecaceae (6.4%) and Araceae (5%). Ornamental species recorded, 57.5% are exotic, 16% have medicinal use and 44% herbaceous. Regression analysis of data across the diversity of species, area and social parameters of the respondents was not significant. The cultivation of ornamental plants in urban backyards Rio Branco assists in the ambience of the residence, landscape improvement, generates welfare for residents at leisure space beyond the conservation of genetic resources.

ESTIMATES OF GENETIC PARAMETERS USING RELM/BLUP FOR INTRAPOPULATIONAL GENETIC BREEDING OF Platonia insignis Mart.

The aim of this study was to estimate genetic parameters to support the selection of bacuri progenies for a first cycle of recurrent selection, using the REML/BLUP (restricted maximum likelihood/best linear unbiased prediction) procedure to estimate the variance components and genotypic values. Were evaluated twelve variables in a total of 210 fruits from 39 different seed trees, from a field trial with an experimental design of incomplete blocks with clonal replies among subplots. The three variables related with the fruit development (weight, diameter, length) showed strong correlation, and where fruit length showed higher heritability and potential to be used for indirect selection. Among the 39 progenies evaluated in this study, five present potential to compose the next cycle of recurrent selection, due they hold good selection differential either to agrotechnological variables as to development of bacuri fruit.

HERITABILITY, REPEATABILITY, AND GENETIC GAINS IN A IMPROVEMENT POPULATION OF CAJUÍZEIRO

O cajuizeiro (Anacardium spp) e uma das muitas especies frutiferas arboreas endemicas da regiao Nordeste do Brasil. O objetivo deste trabalho foi estimar os coeficientes de herdabilidade e repetibilidade das variaveis agrotecnologicas e predizer os ganhos geneticos de uma populacao de melhoramento de cajui da Embrapa Meio Norte. Os dados das variaveis estudadas de cada safra foram avaliados no programa Selegen-REML/BLUP. A ordem das variaveis analisadas foi: V1: peso do fruto (PF, em g), V2: peso do pedunculo (PP, em g), V3: peso da castanha (PC, em g), V4: diâmetro basal (DB, em cm), V5: diâmetro apical (DA, em cm), V6: comprimento do fruto (CP, em cm), V7: firmeza do endosperma (FIRMEZA, em N), V8: teor de vitamina C (VitC, em mg/100g), V9: teor de solidos soluveis totais (SST, em %), V10: pH do endosperma (pH), V11: acidez total titulavel (ATT, em %) e V12: relacao STT/ATT (adimensional). O peso do fruto e teor de vitamina C podem ter seus valores preditos a partir do diâmetro basal e/ou comprimento do pedunculo cujas medidas sao de facil mensuracao. As medianas e altas estimativas dos coeficientes de herdabilidade e repetibilidade possibilitaram selecionar precocemente um dos genotipos, 4, com acuracia a partir de duas medicoes (anos). O genotipo 4 apresentou as maiores medias para os atributos fisicos e tecnologicos do fruto, podendo ser considerado candidato a selecao para reproducao assexuada no cultivo com objetivo duplo (consumo in natura e industrializado).

EFEITO DO SOMBREAMENTO NA ANATOMIA FOLIAR DE PLANTAS JOVENS DE ANDIROBA (Carapa guianensis Aubl.)

The ability to use light varies between species and the success of each individual depends on his morphoanatomical adaptations. The aim of this study was to evaluate the influence of different light intensities on leaf anatomy of seedlings of Carapa guianensis Aubl. Healthy leaves of the second and third nodes were collected from young plants grown in four levels of shading: 30%, 50%, 70% and 0% (full sun) during the eight months of the experiment. Anatomical analyzes were made under Optical Microscopy (OM), from temporary and permanent slides, and Scanning Electron Microscopy (SEM). The stomatal density showed no significant differences. The dimensions of stomata and thicknesses of the leaf tissue were greater with increasing light intensity. C. guianensis presents anatomical plasticity enabling survival in the forest under different lighting

Danos provocados pelo fogo sobre a vegetação natural em uma floresta primária no estado do Acre, amazônia brasileira

The emission of CO2 is an important cause of the greenhouse effect and the Amazonian burns contribute to it. Because of the high moisture retained, the primary Amazon forest is considered immune to fire, however, under abnormal climate conditions it is vulnerable. The objective of this study is to evaluate the effects of fire, originated from forest-fires occurred in 2005, in a natural primary forest in the state of Acre, Brazilian Amazon region. The effects of fire on trees, palm trees and lianas were evaluated in three levels of size: I-DBH≥5 cm; II-5 cm>DBH≥2 cm; and III-DBH<2 cm and height ≥1,0 m. The individuals were evaluated for General Condition (levels I and II), Bark and Cup (Level I) and budding. Five evaluations were made, the first in November 2005 and last in January 2009. The results showed that the smallest subjects were the most impacted ones and showed the highest mortality rates, reaching 80.1 % for Level II and decreasing according to the increasing size of the tree and it is null (0 %) in higher classes. It was observed a growing number of individuals with no apparent damage in all diameter classes and a 43 % increase in the number of species in regeneration, indicating a recovery process of the forest. It was observed a significant reduction of species diversity (15 % in Level I and 33 % in Level II), showing that the forest was modified in its floristic composition. Based on the significant damage caused by only one fire, the case of study, it is expected the incidence of new fires, at short intervals insufficient for the recovery and it will promote the irremediable degeneration of forest.