Resumo em Inglês:

ABSTRACT In Santa Catarina State, forest classification in successional stages is supported by the National Council of the Environment (CONAMA) Resolution. However, this classification presents several inconsistencies. This study aimed to evaluate the classification accuracy of three classifications schemes of successional stages proposed for the Subtropical Atlantic Evergreen Rainforest of the Santa Catarina State. All schemes are based on threshold values of mean height, mean diameter at breast height, and basal area to distinguish between stages. We used structural and diversity data from 207 sample plots within the Santa Catarina’s State Subtropical Rainforest region to classify the respective stands according to the schemes. The classification accuracy of each scheme was evaluated through the application of linear discriminant analysis (LDA). We constructed a predictive equation using the results of the LDA, from the scheme that presented highest classification accuracy. The current classification (CONAMA Resolution) showed an average of 81.87% of classification accuracy, while Scenario A presented 83.73% and Scenario B 78.67%. From Scenario A, we created a predictive equation based on structural and diversity variables. This equation may be used to classify other forest sites, constituting a new proposal for the secondary vegetation classification in Santa Catarina’s State Subtropical Rainforest.

Resumo em Inglês:

ABSTRACT Selecting predictors for species distribution models (SDMs) is a major challenge. In this study, we evaluated a comprehensive set of 62 environmental predictors that may be related to the occurrence of Fagus hayatae. We modeled F. hayatae as a case study to compare model performance through different environmental predictor subsets according to three selection procedures, namely correlation coefficients between predictors, contribution level of predictors, and expert choice of biologically relevant predictors. The three selection procedures provided satisfactory results with high performance using about 6-10 valid predictors but had their respective limitations. Consequently, we suggest a synthetic strtegy of predictor selection. Accordingly, the first step was identifying and eliminating ineffective variables with nonidentifiability by using bivariate scatterplots. Next, calculate the correlation coefficients between other candidate predictors. Finally, comprehensively select the applicable environmental predictors with lower correlation coefficient on the basis of highly contribution level and expert knowledge for SDM of target species.

Resumo em Inglês:

ABSTRACT Equations express that height-diameter relationships are used to estimate tree heights that were not measured in the plots, as well as to calculate their volumes. In this study, we modelled height for Eucalyptus grandis Hill ex. Maiden stands using nonlinear mixed effect models in Mocuba District, Central Mozambique. Models were tested from 1414 trees measured, in 40 plots with dimensions of 20 x 20 m. Model one (M1) was the best in relation to the others according to the evaluated criteria (R2 = 0.9183; RMSE = 0.558; AIC = -1234.8; BIC = -1224.9). The inclusion of the variables dominant height (h100, m), basal area (G, m2.ha-1) and mean basal area diameter (dg, m) in model 1 (M1) within the scope of mixed effect model structures that involved both fixed and random effect parameters (Model 7) provides better fitting and more precise predictions. For calibration of random effects according to plot, height measurement of at least five trees is required (four dominant trees + one tree randomly selected in plot). Our model is site-specific and its application should therefore be limited to the stands with characteristics that were the basis of this study. Further works on recalibration, validation, and verification of our model using a larger dataset collected from a wider range of species distribution will be more interesting.

Resumo em Inglês:

ABSTRACT Water erosion is one of the main problems faced by the Furnas Lake Surrounding Watershed, located in southeast Brazil. The erosive process is intensified by inadequate land occupation of the lake margins where should be riparian forests, or permanent preservation areas (APP), in order to protect water resources. In this context, our work aimed to estimate the soil losses of this watershed using the Revised Universal Soil Loss Equation (RUSLE) in two different scenarios: I - considering the actual occupation of the area, and II - building an alternative scenario where permanent preservation areas were present. Therefore, we considered physical, edaphoclimatic, and land use and management factors. To simulate the presence of preservation areas, we based it on the Brazilian Forest Code (Bill no. 12.651/2012). In the real scenario (I), the total soil loss estimated was 31,580,907.47 Mg.year-1 (32% over the Soil Loss Tolerance) with an average loss of 19.00 Mg.ha-1.year-1, while in the conservationist scenario (II), there was 10% decrease, which means the mitigation of the erosion process as well as of the negative environmental impacts that can be generated by soil degradation.

Resumo em Inglês:

ABSTRACT Paratecoma peroba is a native forest species of great economic and ecological interest, currently at risk of extinction. In addition to the difficulty of finding adult individuals of this species, plant production is limited, so the use of mini-cuttings can facilitate the spread of P. peroba. Thus, the objective of this study was to analyse the effect of different doses of controlled release fertilizer (CRF) on rooting, growth, photosynthetic metabolism and nutritional balance of P. peroba clones propagated by mini-cuttings. Five doses of CRF (0, 2, 4, 6 and 8 kg.m-3) were tested, arranged in a completely randomized design with 12 repetitions and each repetition consisted of eight clones. Evaluations were carried out in the three stages of clones production: 1) Survival at 60 days in a greenhouse, 2) Rooting at 105 days in a shade house; and 3) Evaluation Productivity index, morphological variables, physiological metabolism, and nutritional through macronutrient contents, diagnosis and recommendation integrated system (DRIS) indices and the average nutritional balance index of clones at 120 days in the area of hardening. There was no influence of CRF on survival and rooting of mini-cuttings. The CRF favoured a higher productivity index, vegetative growth and physiological activity of the clones. The 6 kg.m-3 dose was sufficient to obtain nutritionally balanced clones.

Resumo em Inglês:

ABSTRACT Land-use change from herbaceous to woody cover -or vice versa- largely affects water fluxes, which in turn can mobilize existing salts dissolved in the soil, and thereby negatively affect soil and/or water quality and site productivity. Secondary salinization was observed after afforestation at the Northern and Eastern subregions of the Río de la Plata Grassland. Based on this, our objective was to determine the degree of association between the climatic (e.g. water balance), edaphic (e.g. texture, presence of petrocalcic horizons) and biological factors (age of plantation, stand density and stand basal area) with the secondary salinization processes under the particular environmental conditions of the Austral Pampas. The lowest electrical conductivity (EC, µS.cm-1) values were found in sites with sandy-textured soils and negative water balance, regardless of tree canopy cover. When EC differences did occur between land uses of the same site (50% of the sites), in most cases - but not in all of them - the highest EC was measured under tree cover. When salinization was significant, no pattern was observed in the salt distribution along the soil profile. An increase of EC was associated with the oldest-unmanaged plantations, with mean age of 40 years, a period much longer than the productive rotation recommended. Under similar edaphic conditions where salinization was observed (i.e. clayed soils, with naturally high salt level), salinization was not significant in relatively young plantations (<rotation period), demonstrating the key role of forest management to decrease its negative impacts on soils.

Resumo em Inglês:

ABSTRACT The objective of this study was to evaluate the germination potential of Aegiphila brachiata (peloteiro) and its propagation through stem-cuttings, as well as how the age of parental plants and the application indolebutyric acid (IBA) and inoculant of Azospirillum brasilense influence adventitious rooting of the species. Thus, the physical characterization of a seed lot and a germination test were performed, both with or without seed scarification and at three gibberellin concentrations (0, 50 and 100 mg.L-1 GA3). For stem-cuttings, two experiments were carried out with cuttings, one with young individuals and the other with adult trees. In both experiments, stem-cuttings were submitted to treatments with IBA (0, 1500, 3000 and 6000 mg.L-1) and a solution of Azospirillum brasilense (50% and 100% of the commercial concentration) for rooting in a greenhouse for 30 days. No seeds germinated and a barrier of radicle emission was identified in the endocarp. The inoculation of stem-cuttings with A. brasilense revealed no influence in rhizogenesis. The stem-cutting technique from young trees is recommended for plantlet production of this species (53.75% rooting), requiring 6000 mg.L-1 IBA application under the conditions that were adopted. Stem-cuttings from adult trees are not recommended for the production of plantlets of peloteiro (Aegiphila brachiata Vell.) due to the low rooting rates (10%) and high mortality (68.33%).

Resumo em Inglês:

ABSTRACT Toxic metals have become some of the main abiotic agents that influence the stress of organisms due to their numerous agricultural and industrial uses that result in bioaccumulation and toxicity at different levels, depending on the type and concentration in the environment. Aluminum and lead are present as a result of anthropogenic activities and cause soil contamination and, consequently, pollution effects on producers such as plants. In this review, we used meta-analysis techniques to assess the effect of aluminum and lead on plant physiology. We calculated the overall effect size for the response variables photosynthesis, maximum quantum efficiency of photosystem II and plastid pigments (chlorophyll a, chlorophyll b and carotenoids). Moreover, it was possible to test the the effect of each metal and the phylogenetic relationship for the probability of Fabaceae species to respond to the pollution caused by these heavy metals, due to the number of studies found using this family. Overall, exposure to the toxic metals at high magnitudes affects photosynthesis and chlorophyll b (by reducing its amount). When considering the effect of each metal separately, aluminum reduced the content of the chlorophyll a and chlorophyll b. However, lead reduced photosynthesis, maximum quantum efficiency of photosystem II and chlorophyll b. When considering the Fabaceae species, there was no reduction of the parameters analyzed under stress by toxic metals. Therefore, our results confirm that these toxic metals (aluminum and lead) are toxic to plant physiology, mainly affecting the efficiency of the photosynthetic system and the plastid content.

Resumo em Inglês:

ABSTRACT The Atlantic Forest is a biome that has suffered anthropic actions, such as the extraction of hardwood, which can lead to the extinction of endemic species of great economic and ecological value, such as Dalbergia nigra. In this perspective, large-scale multiplication studies are necessary to contribute to the conservation of this species. The objective of this work was to establish a protocol for the in vitro production of axenic seedlings of D. nigra. Four experiments were performed: I. Immersion times in NaOCl. II. Disinfecting agents in seed germination of D. nigra. III. NaOCl toxicity in seeds of the model species Lactuca sativa L. IV. Culture media and glutamine in the germination and initial growth of D. nigra. All experiments were arranged in a completely randomized design. For a better disinfestation and less harmful effects to the seedlings, it is recommended that the seeds be treated with 70% alcohol (1 min) and NaOCl (14 min). NaOCl has a high phytotoxic, cytotoxic, and genotoxic effect, and its mechanism of action in the L. sativa cell cycle is clastogenic and aneugenic, suggesting the formation of abnormal seedlings in D. nigra. The WPM medium and its supplementation with glutamine (0.75 mg.L-1) are recommended.

Resumo em Inglês:

ABSTRACT A resource balance comprises a method to monitor sources and uses of a given material. The wood resource balance analyses origins of wood resources used in the production of semi finished forest products. At the same time, the resource balance helps tracking wood processing residues and its further uses. A primary survey with 113 companies was conducted and official statistics were consulted to carry out the first wood resource balance for Brazilian plantation forests. The balance sheets were analysed for 2008 and 2018. Wood resources consumption increased from 208 to 231 million m³. Wood processing residues volumes had grown by 19 % in the same period. Round wood demand for material use accounted to 66 % in 2018 whilst 99 % of residues were used energetically. The sector’s supply and production sides have shown to be in an exceptional balance. An increase on resource efficiency and cascading uses was observed in Brazil during the analysed period. The plantation forests supplied the greater domestic demand for round wood which relieves use pressure on natural forests.

Resumo em Inglês:

ABSTRACT The objective of this study was to evaluate the effect generated by a thermal treatment on the dimensional changes and compression behavior of three wood species from commercial plantations (Eucalyptus nitens, Tectona grandis and Gmelina arborea). To accomplish the goal, dilatometric and compression tests were performed in the three directions of wood. It was found a high anisotropy of the coefficient of linear thermal expansion (CTE) as well as of the compression strength of the woods. Higher values of CTE in the tangential direction than in the radial direction were measured, meanwhile in the longitudinal direction were null. In terms of mechanical strength, the longitudinal direction showed the highest strength. The radial strength was slightly higher than the tangential one. Thermal treatment increased the strength to compression and the resistance to deformation in the elastic region. The modulus of elasticity increased up to 30.9%, the stress at proportional limit up to 27.3% and the modulus of rupture up to 30.3%, in the longitudinal direction. The thermal treatment had a higher effect on the mechanical properties of the lowest density wood. On the contrary, the mass loss increased for these species, finding values around twice than those obtained for the denser wood.

Resumo em Inglês:

ABSTRACT Cordia (Cordia trichotoma (Vell.) Arrab. ex Steud.) is a native species that has high quality wood and potential for the establishment of commercial plantations. However, its propagation by seeds is difficult, and vegetative propagation is a good alternative. The aim of this study was to evaluate the vegetative propagation of cordia by cuttings from shoots and roots. In one experiment, cuttings from shoots of adult plants were treated with 0 and 40 mM of indolbutyric acid (IBA). In other experiment, cuttings from roots of adult plants were classified by diameter as thick (2.0-3.0 cm) and thin (<2.0 cm) and treated with 0, 20, 40 and 60 mM of IBA. In other experiment, cuttings from roots of three-year-old plants were treated with 0, 20 and 40 mM of IBA. In all experiments, the percentages of survival, rooting and shooting, the number and length (cm) of shoots and roots were evaluated. Cuttings from roots and shoots of adult plants were not responsive to propagation, because they produced new shoots without rooting. Cuttings from roots of young plants differentiate roots, even without AIB application, enabling the production of cordia new plantlets.

Resumo em Inglês:

ABSTRACT The seasonally dry subtropical forest, especially the Espinal forest in central Argentina (one of the most fragmented ecoregions), is affected by intensive agricultural activity. These activities are the main anthropogenic sources of atmospheric nitrogen compounds and their effects on lichens have been extensively studied, making them excellent ecological indicators. However, in the Espinal forest, the agricultural emissions are not monitored therefore analysis of the response of lichen diversity to these activities has a fundamental role in providing baseline data for monitoring. We analyzed changes in the frequency of families and genera of epiphytic lichen communities in 39 circular buffer areas at different scales comprising crop production, stock farming (feedlots), grazing and forest. Significant correlations at different taxonomic levels were detected in relation to land use. Frequency of Physciaceae increased with an increasing area of cropland to a distance of 600 m. Likewise a positive correlation was observed between the frequency of Collemataceae and the forest area. At genus level, Physcia presented a different response to livestock according to the intensity of production, since the frequency of these species increased in forest patches surrounded by grazing but decreased in areas with livestock farming where the stocking density is higher. This result could indicate an eutrophication process in the Espinal ecosystem, even for Physcia species. Our results can be used to start a list of indicator species to impact of agricultural in forest ecosystems.

Resumo em Inglês:

ABSTRACT The present study presents the application of artificial neural network (ANN) to predict the modulus of rupture (MOR) and mass loss (ML) of the fire retarded fiberboard. Hence, the effect of adding the fire retardants including boric acid, borax and ammonium sulfate was evaluated on MOR and ML of fiberboard manufactured at different press temperatures. At first, the experimental design was created based on the Response Surface Methodology, and then the significance of each independent variable with respect to its effect on the responses was evaluated through ANOVA test. It was determined that the positive effects of increasing press temperatures on MOR compensated the negative effects of fire retardant content on it. However, ML decreases more at the same time. ANN results exhibited a good agreement with experimental results. It was shown that the prediction error was in an acceptable range. The results indicated that the developed ANN model can predict the MOR and ML of the fiberboard with an acceptable accuracy. Therefore, applying the proposed model can lead to obtain the desirable outputs of MOR and ML by performing fewer experiments, and spending less time and cost.

Resumo em Inglês:

ABSTRACT Tree-level growth models are being more used in heterogeneous forests, for they can take underlying processes, such as competition, into account. Although it is common in the forest literature to test several indices in order to define the most suitable for each study, the evaluation of plot sizes or competition radii is poorly addressed in competition studies. The objective of this work was to assess the effect of different plot sizes and competitor selection radii on distance-independent and distance-dependent competition indices, as well as test several modifications in previously created indices. We used data of diameter, canopy stratum and crown quality from two stem mapped measurements carried out in a six-year period. Both distance-dependent and independent indices were calculated for different plot sizes and competitor selection radii. The performance of plot sizes and neighborhood radii was evaluated via Spearman’s rank correlation with the annual growth in diameter, and those with the largest correlation coefficient were included in a stepwise regression to estimate diameter growth. For almost all the indices the correlation increased as the plot size or radius increased. A 50 m x 50 m square plot generated the strongest correlation for distance-independent indices. A 20 m radius resulted the largest correlation for the distancedependent indices. Modifications in some of the indices also improved their performance. The stepwise regression selected BAL and Hegyi indices to describe the diameter growth, which means that using only one competition index might not be enough to fully explain the overall competition.

Resumo em Inglês:

ABSTRACT This study aimed to evaluate changes in germination and in the amount of carbohydrates, starch, proteins, and lipids of A. angustifolia seeds at different stages of development. Seeds were collected in the Cotyledonary Stage and Stages I, II, III and IV. Germination, moisture content, dry matter amount, and levels of carbohydrates, starch, proteins, lipids and fatty acids were determined. Both embryo and megagametophyte contained the starch as the large reserve content, while proteins and mainly lipids represented only a small proportion. During seed development, the highest values for germination, starch and soluble carbohydrate content were observed at stage IV. Although, soluble protein content had decreased from Cotyledonary Stage to Stage III, an increase at Stage IV was observed in the embryo. No difference was observed in lipid content. Linoleic acid was more abundant in fatty acids. Thus, A. angustifolia embryo showed an increase soluble protein content, an accumulation of dry matter and soluble carbohydrate content at Stage IV. It seems that these compounds collaborate to faster and higher germination.