Soil fauna is responsible for one-quarter of all species on Earth, and these organisms play crucial roles in many ecosystem functions and services; however, these communities are facing several threats related to human activities, especially in the Cerrado ecoregion, the second largest biome. We aimed to evaluate the soil mesofauna communities in a native savanna (Cerrado) and two l eucalyptus stands to verify differences and infer possible impacts on soil mesofauna abundance and diversity through land-use changes, as well as find correlations between soil chemical parameters and soil mesofauna groups. Pitfall traps were installed in each one of the 12 plots per land-use type to evaluate soil mesofauna abundance and diversity in the dry and rainy seasons, and soil chemical analyses were performed at 0–20 and 20–40 cm depth per plot. We found that Collembola, Isoptera, and Diptera during the dry season collections, and Formicidae, Isoptera, and Diptera in the rainy season collection were more abundant in the Cerrado. The eucalyptus plantations have reduced the abundance of these groups, in addition to also representing a possible loss of biodiversity promoted by these monocultures. The organic matter, Potassium, Calcium, Phosphorous, and pH contents can be used as good soil mesofauna indicators in the Cerrado.
29 February 2020 in iForest - Biogeosciences and Forestry
The use of artificial intelligence to generate information of the savanna’s energy capacity may support sustainable management of those areas. We assessed the efficacy of artificial neural networks (ANNs) combined with satellite data to estimate the energy potential (Pe) for cerradão, a dense savannah-like vegetation type in Brazil. We conducted a forest inventory for measuring dendrometric variables and sampling woody materials and barks in a cerradão area in the state of Tocantins, Brazil. The Pe of cerradão biomass was estimated based on the observed higher calorific power and drier biomass values. Six vegetation indices were retrieved from a RapidEye image and tested for correlation to choose the optimum vegetation index for biomass modeling. The basal area and the Normalized Difference Vegetation Index were used as predictors in the Pe modeling. We estimated an average of 19.234 ± 0.411 GJ ton-1 and 19.878 ± 1.090 GJ ton-1 for higher heating values of the wood species and barks, respectively, and an average Pe of 1022.660 GJ ha-1. The best ANN showed an error of 11.3% by using a structure of two, eight, and one neurons in the input layer, in the hidden layer, and in the output layer, respectively, as well as activation functions of the tangential and sigmoidal types. The validation tests showed no significant difference between the observed and ANN-predicted values. Based on our results, we concluded that Pe can be efficiently predicted by combining ANNs and remotely sensed data, which ultimately is a promising tool for forest sustainable management of the cerrado ecosystems.
The prediction of biological processes, which involve growth and plant development, is possible via the adjustment of mathematical models. In forest areas, these models assist in management practices, silviculture, harvesting, and soil fertility. Diameter, basal area, and height are predictors of volume and biomass estimates in forest stands. This study utilized different non-linear models for estimating biomass and nutrient values in the aerial biomass and roots of an unmanaged eucalypt stand in Cerrado dystrophic soil. It was hypothesized that the models would estimate the nutrients of the aboveground biomass and roots after meeting the selection and validation criteria. By statistical analysis of the parameters and subsequent validation, the Schumacher–Hall model was presented to be the best fit for biomass and nutrients. This result confirmed the ability of different variables, including diameter, basal area, and height, to be predicted. Estimating the nutrient values in the aboveground biomass and roots allowed a better understanding of the quality of the vegetal residues that remained in the soil. For dystrophic soils, which occur in the Cerrado, these estimates become even more relevant.
Em sistemas florestais, a forma natural de aporte de nutrientes se dá através da serapilheira, a qual compreende todo material vegetal depositado ao solo. Logo, vista a importância do tema, o presente trabalho objetivou realizar uma revisão sistemática sobre as diferentes metodologias utilizadas na temática da serapilheira e ciclagem de nutrientes nas diversas fitofisionomias do bioma Cerrado. Foram avaliadas todas as publicações, independentemente do período de publicação, e catalogadas as que se enquadraram na temática: quantificação da produção e decomposição da serapilheira no bioma Cerrado, por meio de buscas no portal periódicos CAPES. Foram selecionados 26 artigos com estudos nas seguintes formações florestais: Cerrado sentido restrito; Cerradão; Matas de Galeria; Florestas de transição Cerrado-Amazônia e plantios homogêneos. A respeito das metodologias, os coletores mais comuns nos trabalhos de produção foram os de formato quadrado (0,25 m²) e o número de coletores variou bastante entre os trabalhos (de 10 a 60 coletores). As folhas contribuíram em torno de 70% ou mais do total da serapilheira. A decomposição apresentou grande variação na massa acondicionada nas bolsas e nos tempos de coleta. Com exceção de um trabalho, os manuscritos avaliados não apresentaram estudos sobre a decomposição de outros componentes da serapilheira, que não a foliar, evidenciando assim a necessidade de estudos nesta temática. Os trabalhos apresentaram tempo total de um ano de avaliação em quase sua totalidade, o que evidencia a necessidade dos monitoramentos de longo prazo, pois estudos com breve duração não permitem avaliar os efeitos de alterações interanuais. As metodologias utilizadas nos trabalhos avaliados apresentaram alto grau de variação, evidenciando a necessidade de padronização que permita a comparação entre estes. Por fim, pôde-se observar que algumas fitofisionomias não possuem nenhuma publicação sobre os temas avaliados, o que reforça a necessidade de estudo da dinâmica da ciclagem de nutrientes nestes locais.
Brazil has a vast reserve of natural forests that belong to the state; hence, the state is responsible for supplying native wood to the market. However, the management in public forests has only begun recently; thus, much research is needed to know about its profitability. This study analyzed the financial feasibility of public forest management by addressing the following aspects: state concession, federal concession, and community forest management. We used the Net Present Value, Annual Equivalent Value, and Average Cost of Production methods to assess financial feasibility and applied the Monte Carlo simulation to estimate the probability of occurrence of NPV values. Community forest management showed profitability and a low occurrence of positive NPV values. The initial subsidies and the absence of royalty payments contributed to their good financial performance. The state and federal forest concessions showed financial unfeasibility and a low probability of profitability, which were justified by a low harvested volume of forest management, a high number of hollow individuals with small dimensions, poor volume estimates, and a high occurrence of species with low commercial values. Financial viability is a critical aspect of public forest management, and the achievement of good results depends on the consideration of several factors and aspects of public forests. Characteristics such as species composition, the distance between the managed areas, and the place of consumption must be considered. Areas that are not financially viable in the current period can be considered for future management and maintenance.