A NON-DESTRUCTIVE METHOD FOR ESTIMATING LEAF AREA OF Ceiba glaziovii (Kuntze) K. Schum.

The determination of leaf area is of fundamental importance in studies involving ecological and ecophysiological aspects of forest species. The objective of this research was to adjust an equation to determine the leaf area of Ceiba glaziovii as a function of linear measurements of leaves. Six hundred healthy leaf limbs were collected in different matrices, with different shapes and sizes, in the Mata do Pau-Ferro State Park, Areia, Paraíba state, Northeast Brazil. The maximum length (L), maximum width (W), product between length and width (L.W), and leaf area of the leaf limbs were calculated. The regression models used to construct equations were: linear, linear without intercept, quadratic, cubic, power and exponential. The criteria for choosing the best equation were based on the coefficient of determination (R²), Akaike information criterion (AIC), root mean square error (RMSE), Willmott concordance index (d) and BIAS index. All the proposed equations satisfactorily estimate the leaf area of C. glaziovii, due to their high determination coefficients (R² ≥ 0.851). The linear model without intercept, using the product between length and width (L.W), presented the best criteria to estimate the leaf area of the species, using the equation 0.4549*LW

Aspectos morfofisiológicos de mudas de Erythroxylum pauferrense Plowman submetidas ao sombreamento

Sunlight directly influences on the development of forest species by affecting the attributes of plant growth and physiology. Among these species, Erythroxylum pauferrense Plowman is considered a rare species, as its distribution is restricted only to the state of Paraíba. Therefore, studies are needed that seek to evaluate the adaptation, development and propagation of the species under different environmental conditions. This study aimed to evaluate morphophysiological aspects of Erythroxylum pauferrense seedlings submitted to different levels of shading. The experiment was carried out under greenhouse condition in a completely randomized design with five treatments (0, 30, 50, 70, and 90% shading) and eight replicates. Growth characteristics, morphofunctional attributes, gas exchange, chlorophyll (Chl) a fluorescence, and Chl content were evaluated. Data were submitted to analysis of variance followed by polynomial regression analysis. Results showed that plants grown under 30 to 50% shading showed higher plant height, stem diameter, absolute growth rate for plant height, leaf dry mass, stem dry mass, total dry mass, Dickson’s quality index, leaf area, and leaf area index, as well as net assimilation rate of CO2, stomatal conductance, transpiration, instantaneous water use efficiency, and Chl a, b, and a+b contents. Therefore, levels from 30 to 50% shading are the most recommended for the production of Erythroxylum pauferrense seedlings. We recommend using Erythroxylum pauferrense to reforest the understory in disturbed areas in Brejos de Altitude and large-scale production of seedlings under intermediate levels of shading.A luz solar influencia diretamente no desenvolvimento das espécies florestais, afetando os atributos de crescimento e fisiologia das plantas. Dentre essas espécies, Erythroxylum pauferrense Plowman é considerada uma espécie rara, pois sua distribuição é restrita apenas ao estado da Paraíba. Diante disso, são necessários estudos que busquem avaliar a adaptação, desenvolvimento e propagação da espécie em diferentes condições ambientais. Este trabalho teve como objetivo avaliar os aspectos morfofisiológicos de mudas de Erythroxylum pauferrense submetidas a diferentes níveis de sombreamento. O experimento foi conduzido em casa de vegetação, em delineamento inteiramente casualizado, com cinco tratamentos (0, 30, 50, 70 e 90% de sombreamento) e oito repetições. Foram avaliadas as características de crescimento, atributos morfofuncionais, trocas gasosas, fluorescência da clorofila (Chl) a e teor de Chl. Os dados foram submetidos à análise de variância seguida de análise de regressão polinomial. Os resultados mostraram que as plantas cultivadas sob 30 a 50% de sombreamento apresentaram maior altura da planta, diâmetro do caule, taxa de crescimento absoluto para altura da planta, massa seca da folha, massa seca do caule, massa seca total, índice de qualidade de Dickson, área foliar e índice de área foliar, bem como a taxa de assimilação líquida de CO2, condutância estomática, transpiração, eficiência instantânea do uso da água e conteúdo de Chl a, b e a+b. Portanto, níveis de 30 a 50% de sombreamento são os mais recomendados para a produção de mudas de Erythroxylum pauferrense. Recomenda-se o uso de Erythroxylum pauferrense para reflorestar o sub-bosque em áreas perturbadas nos Brejos de Altitude e a produção em larga escala de mudas em níveis de 30 a 50% de sombreamento

Estrutura populacional de Microgramma vacciniifolia (Langsd. & Fisch.) Copel em um fragmento de Floresta Ombrófila Aberta no Nordeste Brasileiro

The species Microgramma vacciniifolia (Polypodiaceae) is found as corticicolous and/or growing-rock plant, with a wide geographic distribution, occurring throughout the Americas. The study was conducted in an Open Ombrophylous Forest fragment, located in the municipality of Areia, Paraiba State, aiming to collect data regarding the populational structure of M. vacciniifolia. To make the survey, 10 transects with six plots each with dimensions of 10 x 10 m were established. For the quantitative study, two types of analysis were focused: (I) the horizontal distribution, where were calculated the absolute density (AD), absolute frequency (AF) and Morisita Index of Dispersion (Id); (II) and vertical distribution, where were calculated the absolute frequency of individual phorophytes (AFi), the absolute frequency of specific phorophytes (AFj) and absolute frequency strata (AFe). The number of individuals was correlated with the species, height, and CBH (circumference at 1.3 m above the ground) of phorophytes, edge distance and luminosity. An analysis was made to visualize the spatial distribution of the number of individuals in the studied fragment. The interpolation of the data was made using Natural Neighbor method (NaN). The results showed that the species is well adapted to the environmental conditions of the fragment, present in its different regions. The species was found in phorophytes with different ages (CAP and height), and in all pre-established strata; The results suggest that the taxon has a wide ecological valence for different climatic factors and is able to withstand harsh environments with very different states of conservation.Microgramma vacciniifolia (Langsd. & Fisch.) Copel. pertence à família Polypodiaceae e é encontrada como corticícola e/ou rupícola, com ampla distribuição geográfica, ocorrendo em todas as Américas. O estudo foi conduzido em um fragmento de Floresta Ombrófila Aberta, situado no município de Areia, Paraíba, visando levantar dados referentes à estrutura populacional de M. vacciniifolia. Para o levantamento da espécie, o fragmento foi dividido em 6 regiões com 10 parcelas de 10 x 10 m cada. Para o estudo quantitativo foram feitas dois tipos de análises: (I) a distribuição horizontal, onde foram calculadas a densidade absoluta (DA), frequência absoluta (FA) e Índice de Dispersão de Morisita (Id); (II) e a distribuição vertical, onde foram calculadas as frequência absoluta sobre os forófitos individuais (FAi), frequência absoluta sobre os forófitos específicos (FAj) e freqüência absoluta por estratos (FAe). O número de indivíduos foi correlacionado com a espécie, altura, e CAP (circunferência a 1,3 m do solo) dos forófitos, distância da borda e luminosidade. Também foram feitas análises para a visualização espacial da distribuição do número de indivíduos no fragmento estudado, através de interpolação pelo método Natural Neighbor (NaN). Os resultados obtidos demonstraram que a espécie é bastante adaptada as condições ambientais do fragmento, estando presente em distintas regiões do mesmo. A espécie foi encontrada em forófitos, com diferentes idades (CAP e altura), e em todos os estratos preestabelecidos. Os resultados sugerem que o táxon possui uma ampla valência ecológica para diferentes fatores microclimáticos e é capaz de suportar ambientes com distintos estados de conservação

IMPACTOS DA INVASÃO POR Cryptostegia madagascariensis Bojer ex Decne. (Apocynaceae Juss.) EM REMANESCENTES DE CAATINGA NO MUNICÍPIO DE IBARETAMA, CEARÁ, BRASIL

Cryptostegia madagascariensis Bojer ex Decne. is a shrubby species capable of forming populational massifs in several niches of caatinga and its related ecosystems, especially in the most humid sites, that may change the characteristics of native vegetation, triggering the disappearance of autochthonous species. This study aimed to identify the impacts caused by the invader on the floristic composition and the structure of the shrub-arboreal component. Three areas of investigation were selected, they were termed by: Ambience I – area with a high intensity of invasion, Ambience II – the transition area between I and III (medium intensity), and Ambience III – area with a low intensity of invasion. For the inventory of those areas, it was used the point-centered sampling method (Quarter Method), considering adults those plants that presented the diameter at ground level (DGL) greater than or equal to 3 cm, and height greater than or equal to 1m. For the evaluation of the structure the conventional phytosociological parameters were analyzed, beyond indices of Diversity, Equitability and Environmental Impact of Exotics (IEIE). In the Ambience, I Cryptostegia madagascariensis was responsible for 82% of density, while in the Ambiences II and III, the density of the species was severally reduced (14.2% and 9.6%, respectively).  The diversity, according to the Shannon-Weiner index, was low for the Ambience I (0.85) and higher for the Ambiences II and III (2.67 e 2.50, respectively). Results demonstrate that Cryptostegia madagascariensis affects severely the diversity and the structure of invaded communities, causing loss in the autochthonal biodiversity of caatinga.Cryptostegia madagascariensis Bojer ex Decne. é uma espécie de porte arbustivo capaz de formar maciços populacionais em diversos nichos da caatinga e ecossistemas associados, sobretudo nos sítios mais úmidos, podendo alterar as características da vegetação nativa, causando o desaparecimento das espécies autóctones. Este estudo teve como objetivo identificar os impactos causados pela invasora sobre a composição florística e a estrutura do componente arbustivo-arbóreo. Foram selecionadas três áreas de investigação, sendo denominadas de Ambiente I – área com forte intensidade de invasão, Ambiente II – área de transição entre o I e o III (média intensidade) e o Ambiente III – área com baixa intensidade de invasão. Para o inventário dessas áreas foi empregado o método de amostragem por pontos (Método dos Quadrantes), sendo considerados adultos os indivíduos com diâmetro ao nível do solo (DNS) maior ou igual a 3 cm e altura maior ou igual a 1 m. Para a avaliação da estrutura foram analisados os parâmetros fitossociológicos convencionais, além dos índices de Diversidade, de Equabilidade e de Impacto Ambiental de Exóticas (IIAE). No Ambiente I, Cryptostegia madagascariensis foi responsável por 82% da densidade, enquanto que nos Ambientes II e III, a densidade da espécie foi bastante reduzida (14,2% e 9,6%, respectivamente). A diversidade, pelo Índice de Shannon-Weiner, foi baixa para o Ambiente I (0,85) e maior para os Ambientes II e III (2,67 e 2,50, respectivamente). Os resultados demostram que Cryptostegia madagascariensis afeta drasticamente a diversidade e a estrutura das comunidades invadidas, ocasionando perda da biodiversidade autóctone da caatinga

Estimation of leaf area of Erythroxylum citrifolium from linear leaf dimensions

Erythroxylum citrifolium is a neotropical plant species recorded in all regions of Brazil. Determining leaf area is of fundamental importance to studies related to plant propagation and growth. The objective was to obtain an equation to estimate the leaf area of E. citrifolium from linear dimensions of the leaf blade (length and width). A total of 200 leaf blades were collected in Parque Estadual Mata do Pau-Ferro in the municipality of Areia, state of Paraíba, Northeast Brazil. The models evaluated were: linear, linear without intercept, quadratic, cubic, power and exponential. The best model was determined by the criteria of: high coefficient of determination (R²), low root mean square error (RMSE), low Akaike information criterion (AIC), high Willmott concordance index (d) and a BIAS index close to zero. All of the models constructed satisfactorily estimated the leaf area of E. citrifolium, with coefficients of determination above 0.9050, but the power model using the product between length and width (L*W) ŷ = 0.5966 * LW1.0181 was the best, with the highest values of R² and d, low values of RMSE and AIC, and a BIAS index closest to zero

Características morfofisiológicas em plantas de Erythroxylum pauferrense Plowman sob estresse hídrico

Several abiotic factors, such as water availability, significantly affect the development of forest species found in the understory. This research aimed to evaluate morphophysiological characteristics in plants of Erythroxylum pauferrense submitted to different water regimes. The experiment was developed in a greenhouse at the Federal University of Paraíba, Campus II, Areia, Paraíba, Brazil. The experimental design was in randomized blocks, with five water treatments [100%, 80%, 60%, 40% and 20% of the pot capacity (PC)] and four replications. Growth attributes, morphofunctional aspects, gas exchange, chlorophyll fluorescence and chlorophyll indices were evaluated. The data were submitted for analysis of variance, and in cases of significance, polynomial regression analyses were performed. The plants of Erythroxylum pauferrense submitted to 100% and 80% water levels of the PC present greater development and morphophysiological performance. In comparison, the evaluated parameters were significantly reduced in the regime of greater water stress (20% of the PC). Thus, the water regime of 80% of PC is the most recommended for producing seedlings of Erythroxylum pauferrense, promoting greater growth and significant changes in morphofunctional aspects, gas exchange, chlorophyll fluorescence and chlorophyll indexes.Vários fatores abióticos, como a disponibilidade de água, afetam significativamente o desenvolvimento das espécies florestais encontradas no sub-bosque. Esta pesquisa teve como objetivo avaliar características morfofisiológicas em plantas de Erythroxylum pauferrense submetidas a diferentes regimes hídricos. O experimento foi desenvolvido em casa de vegetação na Universidade Federal da Paraíba, Campus II, Areia, Paraíba, Brasil. O delineamento experimental foi em blocos ao acaso, com cinco tratamentos hídricos [100%, 80%, 60%, 40% e 20% da capacidade do vaso (PC)] e quatro repetições. Foram avaliados atributos de crescimento, aspectos morfofuncionais, trocas gasosas, fluorescência da clorofila e índices de clorofila. Os dados foram submetidos à análise de variância e, nos casos de significância, análises de regressão polinomial. As plantas de Erythroxylum pauferrense submetidas a regimes hídricos de 100% e 80% da PC apresentam maior desenvolvimento e desempenho morfofisiológico. Em comparação, os parâmetros avaliados foram significativamente reduzidos no regime de maior estresse hídrico (20% da PC). Assim, o regime hídrico de 80% de PC é o mais recomendado para produção de mudas de Erythroxylum pauferrense, promovendo maior crescimento e alterações significativas nos aspectos morfofuncionais, trocas gasosas, fluorescência da clorofila e índices de clorofila

Physiological changes in Solanum lycopersicum L. in the presence of root-knot nematodes and salicylic acid

Nematodes of the genus Meloidogyne spp. are one of the tomato culture’s main pathogens. According to their soil infestation level, physiological changes may occur. Consequently, it is extremely important to employ given products to minimize their effect. A feasible option is the salicylic acid, a phytohormone that can induce into resistance due to its ability to increase the production level of some pathogenicity proteins. Therefore, the purpose hereof was to assess the effect of salicylic acid on the physiology of tomato plants subject to different populational densities of Meloidogyne javanica. The design employed was one of randomized blocks, in an incomplete factorial scheme, using the Box Central Compound (BCC) matrix with five nematode populational densities (PD) (0; 5815; 20000; 34184; and 40000 eggs per plant) and five salicylic acid doses (0.0; 0.29; 1.0; 1.71; and 2.0 mM), with four repetitions and two plants per experimental patch. The gas exchanges, fluorescence, and chlorophyll levels were evaluated 45 days after the transplant and soil infestation. The data were submitted for analysis of variance through the F test and, in the significance cases, the polynomial regression analysis was performed. For stomatal conductance, a greater reduction was seen at the PD of 21755 eggs per plant, a fact that might have decreased the liquid assimilation of CO2 and the efficiency of carboxylation. The salicylic acid (SA) affected the CO2 liquid assimilation and the efficiency of carboxylation. The infestation of M. javanica in tomato plants negatively affected the gas exchange and the chlorophyll levels because the SA application did not mitigate the negative effect thereof