The degradation of natural ecosystems triggers global environmental, economic, and social problems. To prevent this, it is necessary to identify the aptitude of priority areas for conservation or use by considering land fragility from multiple environmental and spatial perspectives. We applied the concept of environmental fragility to a hydrographic basin in southeastern Brazil that establishes (i) potential fragility levels according to slope, soil classes, geological domains, drainage hierarchy, and rainfall information using an algebraic map, and (ii) emerging fragility levels via the addition of the land-use parameters. The methodological approach involved the integration of the analytic hierarchy process (AHP) and weighted linear combination (WLC) into a geographic information system (GIS). The medium and slightly low fragility classes predominated in terms of potential (~60%), and emerging (~70%) environmental fragility models used to model the basin. The model indicated that high and extremely high potential fragilities were concentrated in the upper basin, a region that is considered a global biodiversity hotspot. The areas with high/extremely high classes of emerging fragility in the upper basin decreased, indicating that the natural cover classes and land-use types are not in danger. We also introduce acceptable conservation practices for land management and use according to the environmental fragility categories established in the present work. The methodology applied in this study can be replicated in other global ecoregions. It provides low-cost territorial and environmental zoning and flexible replication and can be adjusted by administrators who are interested in land-use planning.

Nitrogen (N) has commonly been applied in Eucalyptus stands in Brazil and it has a direct relation with biomass production and chlorophyll content. Foliar N concentrations are used to diagnose soil and plant fertility levels and to develop N fertilizer application rates. Normally, foliar N is obtained using destructive methods, but indirect analyses using Vegetation Indexes (VIs) may be possible. The aim of this work was to evaluate VIs to estimate foliar N concentration in three Eucalyptus clones. Lower crown leaves of three clonal Eucalyptus plantations (25 months old) were classified into five color patterns using the Munsell Plant Tissue Color Chart. For each color, N concentration was determined by the Kjeldahl method and foliar reflectance was measured using a CI-710 Miniature Leaf Spectrometer. Foliar reflectance data were used to obtain the VIs and the VIs were used to estimate N concentrations. In the visible region, the relationship between N concentration and reflectance percentage was negative. The highest correlations between VIs and N concentrations were obtained by the Inflection Point Position (IPP, r = 0.97), Normalized Difference Red-Edge (reNDVI, r = 0.97) and Modified Red-Edge Normalized Difference Vegetation Index (mNDI, r = 0.97). Vegetation indexes on the red edge region provided the most accurate estimates of foliar N concentration. The reNDVI index provided the best N concentration estimates in leaves of different colors of Eucalyptus urophylla × grandis and Eucalyptus urophylla × urophylla (R² = 0.97 and RMSE = 0.91 g kg⁻¹).

O presente trabalho teve como objetivo avaliar parâmetros fisiológicos de mudas de copaíba produzidas sob o efeito de diferentes níveis de sombreamento e tipos de substratos. O experimento teve a duração de 130 dias e foi conduzido em blocos casualizados no esquema fatorial 5x4, com cinco substratos: Bioplant®; 70% vermiculita + 30% casca de arroz carbonizada; 40% vermiculita + 30% casca de arroz carbonizada + 30% fibra de coco; 50% vermiculita + 30% casca de arroz carbonizada + 20% areia; 70% vermiculita + 15% casca de arroz carbonizada + 15% vermicomposto de resíduo de indústria têxtil; quatro níveis de sombreamento (100, 70, 50 e 30% do pleno sol) e três repetições. O nível de sombreamento de 50% em relação ao pleno sol possibilitou a produção de mudas de copaíba com maiores teores de clorofila b e clorofila total, além de proporcionar os menores valores de transpiração diária e ao longo do dia das plantas. A área foliar, os teores de clorofila e a transpiração das mudas de copaíba independem do tipo de substrato, podendo ser produzidas em qualquer um dos meios de crescimento avaliados.

O presente estudo objetivou avaliar a influência de diferentes níveis de sombreamento e tipos de substratos no desenvolvimento inicial de mudas de copaíba. O experimento foi conduzido no delineamento em blocos casualizados no esquema fatorial 5 x 4. Os tratamentos foram compostos pela combinação de cinco substratos, Bioplant®; 70% vermiculita + 30% casca de arroz carbonizada (70V+30CA); 40% vermiculita + 30% casca de arroz carbonizada + 30% fibra de coco (40V+30CA+30FC); 50% vermiculita + 30% casca de arroz carbonizada + 20% areia (50V+30CA+20A); 70% vermiculita + 15% casca de arroz carbonizada + 15% vermicomposto de resíduo de indústria têxtil (70V+15CA+15VC) e quatro níveis de sombreamento, (pleno sol (0%), 30; 50 e 70%) e três repetições. Foram avaliadas as seguintes variáveis: taxa de crescimento absoluto em altura e diâmetro; sobrevivência; massa seca de folhas, caule e raiz; massa seca total; razão entre massa seca da parte aérea e massa seca de raiz; e a razão de massa foliar. Os resultados demonstram que as mudas de copaíba necessitam de sombra em sua fase inicial de desenvolvimento, sendo o nível de 50% de sombreamento uma alternativa viável para produção de suas mudas. As mudas de copaíba crescidas no substrato 70V+30CA apresentaram maior produção de massa seca total, enquanto no Bioplant® observou-se características inferiores para a massa seca de folha, massa seca total e razão de massa foliar. This study aimed to evaluate the influence of different shade levels and types of substrates in the initial development of seedlings of Copaiba. The trial was conducted in a randomized block design in a factorial 5 x 4 with five substrates, Bioplant®; 70% vermiculite + 30% rice hulls (70V+30CA), 40% vermiculite + 30% rice hulls + 30% coconut fiber (40V+30CA+30FC), 50% vermiculite + 30% rice hulls + 20% sand (50V+30CA+20A), 70% vermiculite + 15% bark carbonized rice + 15% vermicompost residue of textile industry (70V+15CA+15VC); four levels of shading (full sunlight (0%), 30, 50 and 70%) and three replications. We evaluated the following variables: absolute growth rate in height and diameter, survival, dry mass of leaves, stem and root, total dry mass, dry mass ratio of shoot and root dry weight, and leaf weight. The results show that the seedlings need shade Copaiba in its early stage of development, and the level of 50% shading a viable alternative for production of its seedlings. The seedlings grown in Copaiba 70V+30CA produced more total dry mass, while in Bioplant® inferior characteristics observed for dry weight of leaves, total dry weight and leaf weight

Leaf hyperspectral reflectance has been used to estimate nutrient concentrations in plants in narrow bands of the electromagnetic spectrum. The aim of this study was to estimate leaf nutrient concentrations using leaf hyperspectral reflectance and verify the variable selection methods using the partial least squares regression (PLSR). Two studies were carried out using stands with Eucalyptus clones. Study I was established in Eucalyptus stands with three clones, classifying leaves into five colour patterns using the Munsell chart for plant tissues. Immediately after leaf collection, leaf reflectance was read and the chemical analysis was performed. Study II was carried out in commercial clonal stands of Eucalyptus performing the same leaf sampling and chemical analysis as used in Study I. All leaf reflectance spectra were smoothed and three more pre-processing procedures were applied. In addition, three methods of PLSR were tested. The first derivative was more accurate for predicting nitrogen ( R c v 2 = 0.95), phosphorous ( R c v 2 = 0.93), and sulphur concentration ( R c v 2 = 0.85). The estimates for concentrations of calcium ( R c v 2 = 0.81), magnesium ( R c v 2 = 0.22), and potassium ( R c v 2 = 0.76) were more accurate using the logarithm transformation. Only the estimates for iron concentrations were performed with higher accuracy ( R c v 2 = 0.35) using the smoothed reflectance. The copper concentrations were more accurate ( R c v 2 = 0.78) using the logarithm transformation. Concentrations of boron ( R c v 2 = 0.68) and manganese ( R c v 2 = 0.79) were more accurate using the first derivative, while zinc ( R c v 2 = 0.31) concentration was most accurate using the second derivative.

Clonal production of eucalyptus seedlings has made considerable progress in recent years. Significant developments have taken place in irrigation and fertilization systems as well as in management of clonal miniorchards. However, the proportion of leaf area in stem minicuttings remains almost the same as that used in macrocutting systems. This work aimed to evaluate the effect of leaf area reduction on seedling production of eight eucalyptus clones. The experiment was conducted over a period of 105 days using a randomized block design and three replicates in an 8 x 4 factorial arrangement, with eight clones and four leaf reduction levels (0%, 25%, 50% and 75%). Variables evaluated included height, root collar diameter, shoot and root dry matter and relationships between these variables. Experimental results demonstrated that clones behaved differently as to leaf reduction and that the 0% reduction level can be adopted in most clones being evaluated.