Antonio Carlos Ferraz Filho

Spatial Distribution of Aboveground Carbon Stock of the Arboreal Vegetation in Brazilian Biomes of Savanna, Atlantic Forest and Semi-Arid Woodland.

The objective of this study was to map the spatial distribution of aboveground carbon stock (using Regression-kriging) of arboreal plants in the Atlantic Forest, Semi-arid woodland, and Savanna Biomes in Minas Gerais State, southeastern Brazil. The database used in this study was obtained from 163 forest fragments, totaling 4,146 plots of 1,000 m2 distributed in these Biomes. A geographical model for carbon stock estimation was parameterized as a function of Biome, latitude and altitude. This model was applied over the samples and the residuals generated were mapped based on geostatistical procedures, selecting the exponential semivariogram theoretical model for conducting ordinary Kriging. The aboveground carbon stock was found to have a greater concentration in the north of the State, where the largest contingent of native vegetation is located, mainly the Savanna Biome, with Wooded Savanna and Shrub Savanna phytophysiognomes. The largest weighted averages of carbon stock per hectare were found in the south-center region (48.6 Mg/ha) and in the southern part of the eastern region (48.4 Mg/ha) of Minas Gerais State, due to the greatest predominance of Atlantic Forest Biome forest fragments. The smallest weighted averages per hectare were found in the central (21.2 Mg/ha), northern (20.4 Mg/ha), and northwestern (20.7 Mg/ha) regions of Minas Gerais State, where Savanna Biome fragments are predominant, in the phytophysiognomes Wooded Savanna and Shrub Savanna.

Dominant Height Model for Site Classification of Eucalyptus grandis Incorporating Climatic Variables

This study tested the effects of inserting climatic variables in Eucalyptus grandis as covariables of a dominant height model, which for site index classification is usually related to age alone. Dominant height values ranging from 1 to 12 years of age located in the Southeast region of Brazil were used, as well as data from 19 automatic meteorological stations from the area. The Chapman-Richards model was chosen to represent dominant height as a function of age. To include the environmental variables a modifier was included in the asymptote of the model. The asymptote was chosen since this parameter is responsible for the maximum value which the dominant height can reach. Of the four environmental variables most responsible for database variation, the two with the highest correlation to the mean annual increment in dominant height (mean monthly precipitation and temperature) were selected to compose the asymptote modifier. Model validation showed a gain in precision of 33% (reduction of the standard error of estimate) when climatic variables were inserted in the model. Possible applications of the method include the estimation of site capacity in regions lacking any planting history, as well as updating forest inventory data based on past climate regimes.

The coppice-with-standards silvicultural system as applied to Eucalyptus plantations — a review

We review the management of Eucalyptus species under a coppice-with-standards (CWS) silvicultural system. CWS management results in product diversification, permitting production of small and large scale timber from the same stand. Eucalyptus species are suitable candidates for CWS management because: there are large worldwide plantation areas, sprouting capacity is high, and eucalypts are multipurpose species. We discuss (1) short rotation Eucalyptus coppice management for energy and pulping and (2) Eucalyptus seedling management for solid wood products. We review the literature and discuss experiences with Eucalyptus managed under the CWS system. We also assess projects dealing with Eucalyptus coppice management, stand density regulation, pruning, and stand and wood quality. The growth environment of the standard trees (heavy competition up to the first harvest, free growth afterwards) coupled with long rotations (>20 years) results in high quality logs for solid wood products. Early pruning should be applied to enhance wood quality. We propose a system for the silvicultural management of Eucalyptus under the CWS system, elaborating on the consequences of initial planting density, site productivity, and standard tree densities as well as timing of basic silvicultural applications.

Dominant height projection model with the addition of environmental variables

This study investigated the behavior of climatic variables inserted as inclination modifiers of the Chapman-Richards model for estimating dominant height. Thus, 1507 data pairs from a Continuous Forestry Inventory of clonal eucalyptus stands were used. The stands are located in the States of Espirito Santo and southern Bahia. The climatic variables were inserted in the dominant height model because the model is a key variable in the whole prognosis system. The models were adjusted using 1360 data pairs, where the rest of the data was reserved for model validation. The climatic variables were selected by using the Backward model construction method. The climatic variables indicated by the Backward method and inserted in the model were: mean monthly precipitation and solar radiation. The inclusion of climatic variables in the model resulted in a precision gain of 19.8% for dominant height projection values when compared with the conventional model. The advantage of the method used in this study is the actualization of inventory data contemplating climatic history and productivity estimates in areas without prior plantation.

Viability of Puccinia psidii urediniospores stored in different environments

The objective of this study was to evaluate the viability and infectivity of urediniospores stored in liquid nitrogen (-196oC), deep-freezer (-80oC), modified-refrigerator (5oC), biochemical oxygen demand (BOD 25oC) and herbarium specimens (25oC), for 150 days. The urediniospores were multiplied in Rose Apple plants (Syzygium jambos) and stored in the above conditions. Every 30 days, the germination and infectivity were evaluated, the first in vitro and the second on Eucalyptus grandis plants. The viability and infectivity of urediniospores stored in BOD and herbarium specimens were not preserved. The maximum germination (24.9%) and infectivity (162 pustules/leaf) occurring in modified-refrigerator environment were higher at 17.6 and 30 days, respectively. Urediniospore germination was highest when preserved in deep-freezer (34.3%) and liquid nitrogen (36.3%), at 45 and 40 days, respectively. The highest infectivity occurred at 60 days for the deep-freezer (77 pustules/leaf) and 90 days for the liquid nitrogen (67 pustules/leaf). Urediniospores kept in deep-freezer, liquid nitrogen, and modified-refrigerator maintained their viability and infectivity for 150 days.

Sustainable Forest Management of Native Vegetation Remnants in Brazil

A region’s species diversity is an important factor, resulting as a component of social and economical development when used wisely. The correct commercialization of a region’s natural resources guaranties the preservation of local culture and habitat maintenance by means of the obtained income. Hence, the idea of sustainability arises, a widespread theoretical theme which is beginning to gain force in Brazil’s consumer market. The principal conceptual shift was the erroneous notion that timber resources from forests are inexhaustible, since the processes of recomposition/restoration naturally occur after exploration. Indeed a system is capable of regeneration, but this is tied to a series of factors that are usually not respected in areas illegally explored. According to a conference realized in Melbourne by Raison et al. (2001), the concept of sustainability must encompass social and economic conditions such as: respect the forest growth rate; legislation based control; productive capacity; ecosystem’s health and vitality; soil and water resource protection; carbon balance and preservation of biological diversity. Under this scenario, Brazil presents great potential for the use of its natural resources. This is due to the country’s vast territorial extension (8.5 million km2) and high diversity of recurrent vegetation physiognomies. The country possesses about 5.2 million km2 of forest land (60% of its territory), of this total, 98.7% consists of natural forest formation and 1.3% of planted forests. The forest types found in Brazil can be classified as Cerrado (Brazilian savanna), Amazonia (tropical rainforest), Mata Atlântica (Atlantic rainforest), Pantanal (wetlands) and Caatinga (semi-arid forest) as well of transition areas which promotes a mixture of habitats. In many cases, the deforestation of these environments is associated with illegal logging practices coupled with agriculture and cattle-raising. The damage caused by this include modifications of the carbon cycle and consequential rise of CO2 emissions; forest fragmentation; alteration of the hydraulic cycle; species extinction; rural exodus and loss of local fauna and flora diversity. Possibly the most logical use of these forests is the application of sustainable forest management for wood production destined for fire wood, charcoal and logs for industrial purposes. The motives for this strategy are evident, involving aspects attached to the reduction

African Mahogany (Khaya spp.) Cultivation and the Increase of the Activity in Brazil

O setor florestal brasileiro esta em plena expansao e com um aumento gradativo de investidores florestais optando pelo cultivo de especies de madeira nobre. O mogno africano (Khaya spp.) e uma especie que vem se destacando na preferencia dos empresarios como opcao no investimento florestal. Porem, estudos e pesquisas sobre a especie, principalmente no Brasil, sao escassos. Assim, a presente revisao procurou reunir diversas fontes de publicacao, nacionais e internacionais, abordando aspectos historicos do mogno, buscando aclarar as caracteristicas da especie e a experiencia de outros paises no manejo dessa cultura.

SITE QUALITY CURVES FOR AFRICAN MAHOGANY PLANTATIONS IN BRAZIL

Site quality estimation is an important tool in forest management since it is useful for modeling growth and yield for even-aged stands. Data from African mahogany (Khaya ivorensis A. Chev.) Brazilian plantations were used to develop a model to predict dominant height growth, comparing dynamic base-age invariant site index models with the guide curve method (static models). For the evaluation of the candidate models qualitative and quantitative criteria were used. We also verified the stability of the candidate models, preferring a model providing fewer site class changes when predicting site index from different ages. The Lundqvist-Korf function fitted with the guide curve method proved to be effective and accurate for site classification and dominant height predictions of African mahogany stands. The range of observed site index, at a reference age of 15, was between 17 and 33 meters.

ESTIMATING PRECISION OF SYSTEMATIC SAMPLING IN FOREST INVENTORIES

A tecnica de amostragem comumente usada em inventarios florestais e a amostragem sistematica. Objetivou-se avaliar o estimador da variância da media proposto por Cochran, no procedimento de amostragem sistematica, em florestas com alto e baixo percentual da area amostrado. As areas contemplaram a vegetacao nativa de Minas Gerais. Para verificar o comportamento dos estimadores numa situacao com alto percentual de area amostrado, utilizou-se o fragmento onde foi efetuado o censo. Os demais se adequaram as situacoes de baixo percentual amostrado, observando-se o comportamento da precisao do inventario, a partir do uso do estimador de Cochran. Como resultado para o fragmento onde se fez o censo, a estrutura do coeficiente de correlacao proposto por Cochran se manteve, aproximadamente, constante para a area e, reduzindo a intensidade de amostragem, o impacto do estimador de Cochran diminuiu. Para os fragmentos com baixo percentual amostrado, a intensidade amostral e a chave para a correlacao proposta por Cochran: impactar na precisao do inventario florestal, sendo indicado o uso desse estimador para fragmentos onde ha uma intensidade amostral superior a 10% da area inventariada.

Determinação do volume de madeira em povoamento de eucalipto por escâner a laser aerotransportado

The objective of this work was to evaluate the possibility of estimating the diameter at breast height (DBH) with tree height and number data derived from airborne laser scanning (LiDAR, light detection and ranging) dataset, and to determine the timber volume of an Eucalyptus sp. stand from these variables. The total number of detected trees was obtained using a local maxima filtering. Plant height estimated by LiDAR showed a nonsignificant tendency to underestimation. The estimate for DBH was coherent with the results found in the forest inventory; however, it also showed a tendency towards underestimation due to the observed behavior for height. The variable number of stems showed values close to the ones observed in the inventory plots. LiDAR underestimated the total timber volume in the stand in 11.4%, compared to the total volume delivered to the industry. The underestimation tendency of tree height (5% mean value) impacted the individual tree volume estimate and, consequently, the stand volume estimate. However, it is possible to obtain regression equations that estimate DBH with good precision, from the LiDAR plant height derived data. The parabolic model is the one that provides the best estimates for timber volumetric yield of eucalyptus stands.