Calophyllum Brasiliense Research Articles

Transplanting naturally regenerated tree seedlings for tropical forest restoration: a case study of Calophyllum brasiliense and Vochysia guatemalensis in Mexico

Plant species produce far more seedlings than those surviving to adulthood. It would seem reasonable to take advantage of that excess production, by relocating seedlings to desired restoration sites. There is, however, little information available on this issue. In the present study, we collected naturally regenerated seedlings of two native species, Calophyllum brasiliense (“barí”) and Vochysia guatemalensis (“corpo”), in old‐growth forest patches, and transplanted them for the enrichment of a secondary tropical forest in Veracruz, Mexico. For transplanted C. brasiliense seedlings, overall survival was 32% after 20 months, and for V. guatemalensis seedlings it was 66% after 26 months. The mean height (±standard error) of all C. brasiliense and V. guatemalensis seedlings that survived until the end of the study, was 33 ± 2 cm (from initially 12.9 ± 0.2 cm) and 52 ± 5 cm (from 4.6 ± 0.1 cm), respectively. We applied a cost–benefit model to assess the trade‐off between initial‐investment costs and the resulting survival of transplanting naturally regenerated seedlings in the current study, in comparison with direct seeding (with and without the protection of seeds and emerged seedlings) reported in a previous study for the same area and species. For C. brasiliense, the success of transplanting naturally regenerated seedlings was always inferior to direct seeding without protection, whereas for V. guatemalensis it was always superior. Comparing the transplantation of naturally regenerated seedlings with direct seeding with protection, the best propagation strategy depended on the (monetary) value that a treelet is expected to be worth after 2 years.

Initial growth and physiology of guanandi (Calophyllum brasiliense Cambess) seedlings treated with humic acids and aqueous vermicompost extract

ABSTRACT The guanandi is a tropical tree from the American continent suitable to compose agroforestry systems and forest-farming-livestock integration whose growth and development stages can be enhanced with the use of biostimulants. In this work, humic acids (HA) and aqueous extracts produced from vermicomposting cattle manure (AEVC), biostimulants commonly employed in short-cycle crops, were characterized and evaluated for initial growth and gas exchange in guanandi seedlings. The HA showed higher levels of C and N and lower H and O compared to AEVC, in addition to three times higher total acidity, higher aromaticity index, and clearer signals regarding symmetric stretching in carboxyl groups and C-O stretching of polysaccharides. Greater stimulation of guanandi growth, via the concentration-response test, was observed for concentrations of 22.24 mg L−1 for HA and 25.55 mg L−1 for AEVC. Increases in net CO2 assimilation, stomatal conductance and transpiration were detected only in seedlings receiving HA. Main root diameter, leaf area and aboveground wet mass increased for both treatments with HA (19.9, 11.0, and 22.8%) and AEVC (16.9, 11.2, and 18.6%). The set of responses associated with the use of HA and AEVC allow categorizing these materials as biostimulants capable of enhancing the initial growth of guanandi seedlings.

Mineral fertilization in tropical reforestation: seedling growth and survival of ten native tree species in Tabasco, Mexico

A reforestation trial was carried out with ten native tree species under four different doses of mineral fertilizer in the lowland tropics in Tabasco, Mexico. In six one-hectare plots, 2415 seedlings of Brosimum alicastrum, Calophyllum brasiliense, Ceiba pentandra, Colubrina arborescens, Diphysa americana, Enterolobium cyclocarpum, Handroanthus chrysanthus, Pimenta dioica, Pouteria sapota, and Tabebuia rosea were planted in a randomized design. The mineral fertilizer consisted of a single initial dose of 0 g, 150 g, 375 g or 750 g nitrogen-phosphorus-potassium (NPK), as well as micronutrients (Ca, Cu, Fe, Mg, Mn, Zn, S). First-year survival and median height increment of transplanted seedlings were analyzed with statistical confidence intervals. Whereas overall first-year survival for Ceiba pentandra for all fertilization doses combined was 66%, it was only 12% for Brosimum alicastrum. On the other hand, median height increment was 102 cm for Enterolobium cyclocarpum, whereas it was only 7 cm for Pimenta dioica. The survival of six of the planted species was apparently affected by the salinity effect caused by mineral fertilization. The only species that benefited from mineral fertilization in a statistically significant way was C. pentandra. In conclusion, mineral fertilization in tropical reforestation is not recommended in general. Appropriate species selection is far more important for favorable survivorship and height increment.

Medicinal plants with potential antihypertensive properties: emphasis on natural products from the Brazilian Cerrado

ABSTRACT Arterial hypertension is a worldwide public health problem and the search for new medicines is one of the biggest challenges for the treatment of this pathology. Secondary metabolites of plants exhibit pharmacological properties of great phyto therapeutic interest. Cerrado is one of the largest biomes in Brazil and research with Cerrado plants as therapeutic resources is of growing interest. Our objective was to compile data regarding the Cerrado plants that already have some of their active compounds described and may potentially be used to treat arterial hypertension. We concluded that flavonoids, tannins, steroids and saponins exhibit important properties to low blood pressure. Thus, the species from Cerrado Brazilian such as pau-paraíba (Simarouba versicolor), pau-santo (Kielmeyera coriacea), abiu-do-cerrado (Pouteria torta), guarandi (Calophyllum brasiliense), bacaba (Oenocarpus bacaba), puçá-amarelo (Mouriri elliptica), fava-de-anta (Dimorphandramollis), murici (Byrsonima crassifolia) and cereja-do-cerrado (Eugenia calycina) are strong candidates for future herbal studies in this field.

Taro production, phytomass input by Sesbania and Flemingia and improvement in soil fertility in agroforestry systems in floodplains

Floodplains were the first deforested areas for agriculture use all over the world. In Brazil these areas can be restored by the growth of guanandi Calophyllum brasiliense, a slow-growing native forest species adapted to flooding. The aims of this study were to: (i) evaluate the taro, Colocasia esculenta, management under two agroforestry systems (AFS) (Simple and Biodiverse) in succession to a reforestation with guanandi, (ii) evaluate the contribution of macronutrients from the green manure Flemingia macrophylla and Sesbania virgata, both managed using pruning for green manure in the respective AFSs, and (iii) the effects on soil nutrients levels compared to monoculture of guanandi (control). The randomized block was designed with eight replication and 216.0 m² plots with four rows of six guanandi trees in each line. In the simple AFS (SAFS), the taro was intercropped with Flemingia and in the biodiverse AFS (BAFS), Sesbania, banana shrub (Musa sp.), edible palm (Euterpe edulis) and fourteen species of native trees were included. Production was evaluated in seasons with high rainfall and water scarcity. With floods the taro has produced around 15 Mg ha-1 of marketable corms in the SAFS and 9 Mg ha-1 in the BAFS, but the drought has made commercial production unfeasible, with no differences between cormels and corms planting. However, enough rhizomes were harvested for a new planting. Flemingia has accumulated 17 Mg ha-1 of fresh matter and Sesbania contributed with 2 Mg ha-1. Soil pH and macronutrient content, especially K, were significantly higher in AFSs areas compared to guanandi monoculture.

NMR and X-ray studies of apetalic acid isolated from Calophyllum brasiliense and of its chiral amides

The tropical tree Calophyllum brasiliense Cambess. (Clusiaceae) grows in rain forests from Brazil to Mexico. Its leaves, as well as those of other Calophyllum species, are rich sources of chromanone acids, such as apetalic acid, isoapetalic acid, and their derivatives. Apetalic acid has shown significant antimycobacterial activity. The biological activity of apetalic acid has been related to the configuration of three asymmetric centers and the stereochemistry of the molecule; however, the C-19 configuration in the acidic side chain has not been fully resolved. For this reason, the unequivocal determination of the absolute configuration by means of X-ray crystallography in a sample of unique homogeneous apetalic acid stereoisomer was the most important point to start this study. Chiral amides were prepared using the carboxyl group. We determined the C-19 stereochemistry of apetalic acid and its specific chiral derivatives using NMR, X-ray diffraction, and molecular mechanics. Finally, we observed that steric hindrance in the side chain of apetalic acid leads to restriction of rotation around the pivotal linkage C-10–C-19, establishing chiral centers at C2(R), C3(S), and C19(R). We were able to separate the derivatives of these two high-rotatory-barrier conformers of apetalic acid by forming diastereoisomeric amides with phenylglycine methyl ester having a chiral center at C-2′. Our results confirmed the existence of atropisomerism in the apetalic acid molecule.

Dung beetle activity had no positive effect on nutrient concentration or performance of established rainforest seedlings

AbstractDung beetle activity causes many changes in the soil when they remove feces from the surface. In temperate grasslands and in greenhouse experiments, these changes have been found to positively affect established plants, but information about these effects under natural conditions in tropical forests is practically nonexistent. In a tropical rainforest (Los Tuxtlas, Mexico), we carried out field experiments with seedlings of six tree species (Brosimum alicastrum, Calophyllum brasiliense, Cymbopetalum baillonii, Diospyros digyna, Omphalea oleifera, and Poulsenia armata), to assess whether feces burial by dung beetles had any positive effect on them. We estimated foliar nitrogen and phosphorus, seedling survival, growth and resource allocation, under three treatment levels: (a) feces added and beetles active, (b) feces added and beetles excluded, and (c) no feces added (and consequently no beetles active). We analyzed data at two levels: community (all plant species together) and individual species. Dung beetle activity did not increase the concentration of foliar nutrients or seedling performance (survival, growth); in one species, it modified resource allocation. At the community level and for two species, dung beetle activity decreased the probability of seedlings growing in height. Our study provides evidence on how extrapolating the effects of dung beetle activity from other study systems into tropical forests can be problematic. More studies will be needed before we can have a clearer idea of the effects that feces burial by dung beetles have on established plants in tropical forests.Abstract in Spanish is available with online material.

Sapling Survival and Growth in a Restoration Project of a Drained Wetland Forest in Southeastern Brazil

Abstract The aim of this research was to evaluate the survival and growth of native tree saplings planted in a drained Mauritia flexuosa palm swamp (vereda) in southeastern Brazil, and to identify suitable species for restoration projects in these hygrophilous environments. Total sapling survival at one-year post-planting was 48%. The species with highest sapling survival and growth were Croton urucurana, Cecropia pachystachya, Erythroxylum citrifolium, Hirtella gracilipes and Tapirira guianensis. Lowest survival and growth were found in Mauritia flexuosa, Piper aduncum, Calophyllum brasiliense, Calyptranthes brasiliensis, Myrsine umbellata, Ladenbergia cujabensis and Ficus sp. We indicate the high-survival species for the restoration of these environments. Typical wetland species attained low survival and growth, indicating the negative influence of anthropization on this ecosystem’s resilience, and highlighting the importance of studies investigating suitable strategies to restore them.

Comparative herbaceous phytosociology in agroforestry and Calophyllum brasiliense monoculture on a river terrace

Invasive forage grasses, especially the Urochloa genus, impact reforestation worldwide. The aim of this study was to evaluate management influence on phytosociology of the herbaceous layer, defined as the layer of herbs, sub-shrubs, shrubs and vines, in two agroforestry systems (AFS) (Simple and Biodiverse) in succession to a reforestation of guanandi (Calophyllum brasiliense), compared to monoculture of this specie taken as control. The experiment was conducted in Pindamonhanga (SP), Brazil, from 2011 to 2014, in a randomized block design with eight replications and 144.0 m² plots. In Simple SAF area, food crops were grown alongside C. brasiliense rows: sweet cassava (Manihot esculenta) in rotation with arrowroot (Maranta arundinacea), pigeon pea (Cajanus cajan), banana shrub (Musa sp.), and juçara palm (Euterpe edulis). In Biodiverse AFS, fourteen native tree species were also planted alongside the food crops. Altogether 41 non-stratified species, 38 genera and 24 botanical families were identified; the most abundant families were: Asteraceae, Poaceae e Cyperaceae. The similarity between the areas diverged after three years of management, with the predominance of Commelina benghalensis and M. arundinacea in the AFS areas and Urochloa decumbens in the monocultive, mainly, due to the shadow gradient established for the three systems.

Spatial distribution of single specie dominant forests of Erythrina fusca Lour. at the Taiamã Ecological Station, Pantanal, Mato Grosso, Brazil

The Pantanal biome has a great variety of habitats where plant species are distributed according to their particularities. This study aimed at evaluating the spatial distribution of arboreal/shrub vegetation in areas of single specie dominance Erythrina fusca forests. An aggregation test (K(t)) for E. fusca and spatial dependence tests (K(12)) between E. fusca and Calophyllum brasiliense, as well as Alchornea discolor and Banara arguta were performed. The correlation of the distance from the beginning of the plots (riverbank) to the abundance of individuals was tested, and finally, the Kernel density was estimated. We found that E. fusca is randomly distributed throughout the area, that the distribution of C. brasiliense and A. discolor is dependent on E. fusca, and that of B. arguta is not. The correlation analysis pointed to a decrease in the abundance of the community from the riverbank to the interior of the island, with a smaller reduction in the population of E. fusca. The density was higher in the regions close to the river. In addition, sites with a high concentration of individuals close to the elevations created by the roots of E. fusca were verified. The distribution of individuals was related to the flood pulse and the adaptive processes of plant establishment, where the flooding selects the species most tolerant to this type of environment, and the formation of higher microrelief in the landscape can increase the dispersion of the species. This points out that any disturbance that may occur in the flood pulse will change the environmental balance.

Mammea type coumarins isolated from Calophyllum brasiliense induced apoptotic cell death of Trypanosoma cruzi through mitochondrial dysfunction, ROS production and cell cycle alterations.

Chagas Disease is a neglected tropical disease caused by the protozoan parasite Trypanosoma cruzi which affects 6-8 million people, mostly in Latin America. The medical treatment is based on two nitroimidazole compounds, which have limited effectiveness in the chronic phase of the disease and produce several adverse effects; consequently, there is an urgent need to develop new, safe, and effective drugs. Previous reports had shown that natural coumarins, especially mammea A/BA isolated from the tropical tree Calophyllum brasiliense, is a promissory molecule for developing new drugs, due to its potent activity, higher than benznidazole, selectivity, and its low toxicity in mice. However, its mode of action is still unknown. In the present work, we evaluated the mechanism of action of the coumarin mammea A/BA (93.6%), isolated from the tropical tree C. brasiliense on Querétaro strain (Tc1) of T. cruzi. This compound was tested in vitro on epimastigotes and trypomastigotes of T. cruzi for intracellular esterase activity, plasma membrane integrity, phosphatidylserine exposure, ROS production, mitochondrial membrane potential, caspase-like activity, DNA integrity, cell cycle and autophagy. Mammea A/BA showed a 50% lethal concentration (LC50) of 85.8 and 36.9μM for epimastigotes and trypomastigotes respectively. It affected intracellular esterase activity, produced important plasma membrane damage and induced phosphatidylserine exposure. An increase in reactive oxygen species (ROS) and decrease in mitochondrial membrane potential were detected. Caspase-like activity was present in both parasite forms producing DNA integrity damage. This compound also induced a cell cycle arrest in the G1 phase and the presence of autophagy vacuoles. The above data suggest that mammea A/BA induce cell death of T. cruzi by autophagy and apoptosis-like phenomena and support our suggestion that mammea A/BA could be a promising molecule for the development of new drugs to treat Chagas Disease.

Calophyllum brasiliense Cambess: An alternative and promising source of shikimic acid

Shikimic acid is the starting material for the synthesis of the antiviral oseltamivir phosphate, a front-line combatant against the human influenza A and B viruses. Nowadays, the demand for shikimic acid is met by seeds of Chinese star anise (Illicium verum), which grows exclusively in southern China. In the current work, the Calophyllum brasiliense plant is suggested as an alternative source of natural shikimic acid, which was extracted, purified and quantified by high performance liquid chromatography. The presence of shikimic acid in the extract of C. brasiliense was confirmed by nuclear magnetic resonance and mass spectrometry analysis. By using a simple and rapid extraction procedure, we showed that the content of shikimic acid in C. brasiliense leaves is 3.79%. Because C. brasiliense has some additional advantages over Chinese star anise, such as geographical distribution, ecological plasticity, natural regeneration, and versatility regarding large-scale cultivation, it may be a viable and promising source of shikimic acid, with potential industrial uses.

Crescimento do guanandi e produção de mandioca e araruta em sistemas agroflorestais

No Vale do Paraíba do Sul, entre os estados do Rio de Janeiro e São Paulo, a substituição da Mata Atlântica para o cultivo do café degradou os solos e os cursos d’água. O cultivo de espécies florestais pode ajudar a restaurar esse ambiente. O guanandi (Calophyllum brasiliense Cambess.) é uma espécie florestal nativa com grande potencial de exploração econômica da madeira. O seu cultivo em sistema agroflorestal – SAF pode tornar-se mais vantajoso devido o seu moderado crescimento. Os objetivos com essa pesquisa foram comparar o crescimento do guanandi em monocultura e na diversificação agroflorestal em SAFs simples e biodiverso, assim como avaliar o desempenho da mandioca (Manihot esculenta Crantz.) e araruta (Maranta arundinacea L.) nesses sistemas, em ciclos com alta precipitação pluvial e escassez hídrica. O SAF biodiverso foi acrescido de feijão guandu, bananeira, palmeira juçara e diversidade arbórea. Os sistemas agroflorestais não prejudicaram o crescimento do guanandi, que incrementou a circunferência a altura do peito no SAF simples após três anos de conversão. As culturas alimentares de mandioca e araruta apresentaram desempenho compatível com a densidade de plantio utilizada nos SAFs, com produções significativamente superiores no SAF simples. A araruta suportou o estresse ambiental em ambos SAFs e dispensa o replantio, ocupando naturalmente o sub-bosque. O SAF simples é um sistema para agricultores interessados em obter o máximo rendimento de cultivos anuais em associação com a espécie florestal. O SAF biodiverso é adequado para diversificar a produção agrícola e restaurar o ambiente concomitantemente.

Subsidies for propagation of native species in Brazil with medicinal potential: Calophyllum brasiliense Cambess

Abstract: Calophyllum brasiliense Cambess. (guanandi) is a native species with medicinal potential and also generates expectation for commercial use (wood) and for recovery of degraded areas. These seeds have physical and mechanical dormancy, requiring techniques for dormancy release; knowledge of seed and seedling morphology that assists laboratory analysis and propagation of the species is also necessary. The objective of this study was to describe the morphological structures of the seeds and normal and abnormal seedlings of guanandi, and also investigate if complete extraction of the endocarp and the seed coat to overcome dormancy will affect the morphology and initial plant development, and consequently production of transplants. Guanandi seeds are large (1000 seed weight of 1480.9 g) with a hard seed coat; cotyledons account for most of the embryo and serve as a reserve; the embryonic axis is small (1.0-2.0 mm) in relation to the seed, yet it is differentiated. The seedlings have hypogeal cryptocotylar germination, with cotyledonary petioles, taproot, and epicotyl developing into a long stem and a tip protected by cataphylls. The main abnormalities in seedlings are related to the root system. Extraction of the endocarp and seed coat does not alter the morphology of seedlings and promotes their greater development, which may be an advantageous strategy.

Nutritional evaluation of Guanandi seedlings fertilized with sewage sludge

The generation of sewage sludge and the concern with their fate has greatly increased. The objective of this study was to assess the effects of using in natura (SS) or composted sewage sludge (SSC) in comparison with mineral fertilizer (MF) application and a control (CT) treatment on the nutritional status of Guanandi (Calophyllum brasiliense Cambess.) seedlings in a typical Red Oxisol in Brazil. The leaf-level nutritional responses of the Guanandi seedlings to these three different fertilizers and the control were evaluated at 90 and 180 days after planting. Nutritional data of leaf variables were compared between the treatments by means of one-way analysis of variance using the F test and a pair-wise comparison of means done by Tukey’s test. The seedlings that received SS or SSC showed deficiencies in Ca, Mg, and Mn, which were confirmed by a visual diagnosis of their leaf symptoms. However, at 180 days after planting there were significant differences (p < 0.05) for K that was greater for MF, SS and SSC than CT, Mg, with SSC larger than SS, and for S that was greater with SS and SSC uses relative to MF. The results highlight the potential for using SS and SSC, after adding KCl and lime, although the Guanandi was highly demanding of Ca, Mg, and Mn. However, they were able to nutritionally supply seedlings, although the short-term cannot be conclusive as regards the exclusive use of them in place of mineral fertilizers.

Native Species Valuable timber plantations in Northern Guatemalan Humid Lowlands: ecological features and silvicultural feasibility

The North Humid Guatemalan Lowlands contains a significant diversity of tree species, incluiding some valuable-timber producers; these species are threatened by commercial overexploitation and habitat loss due to deforestation. The cultivation of these species in forest and agroforest plantations is a potentially viable optiontheir conservation and commercial harvesting, something that has been promoted with Government Incetemala during the past two decades. However, these species have not been widely planted, among othebecause knowledge on their ecological requirements and silviculture is scarce. A characterization of momixed plantations with 14 native valuable-timber species was made in the Humid Lowlands of Northeranalyzing for each species frequency of association and accompanying species, planted area, the main etures and growth rates. To gather information, we combined field observation and measurements with iliterature review. Based on our survey, main management challenges for cultivation of the species were described. Valuable-timber native trees could potentially be sustainably cultivated in the study zone in diffforest plantations and agroforestry schemes of coffee, cacao, cardamom and cattle; considering their suitdiversified systems, growth performance and farmer’s preferences, Swietenia macrophylla, Cedrela odordonnell-smithii, Calophyllum brasiliense and Cordia alliodora were the species with the higher potentiain plantations. However, several unsolved problems continue restricting the cultivation of these species itherefore, is essential a careful design and management.

DESENVOLVIMENTO INICIAL E EFICIÊNCIA DE USO DE ÁGUA E NITROGÊNIO POR MUDAS DE &lt;i&gt;Calophyllum brasiliense, Eucalyptus urograndis, Tabebuia impetiginosa &lt;/i&gt; E &lt;i&gt;Toona ciliata&lt;/i&gt;&lt;sup&gt;1&lt;/sup&gt;

O conhecimento sobre o desenvolvimento inicial das mudas é fundamental para o sucesso de atividades de reflorestamento e de plantio em florestas naturais. O objetivo deste trabalho foi avaliar o desenvolvimento inicial e a eficiência de uso de água e nitrogênio por mudas de quatro espécies florestais nativas e exóticas (Calophyllum brasiliense (nativa), Eucalyptus urograndis (exótica), Toona ciliata (exótica) e Tabebuia impetiginosa (nativa)) com idade de aproximadamente 120 dias após a semeadura por 120 dias após o transplante em condições de casa de vegetação. Foram realizadas amostragens destrutivas para avaliar a biomassa seca (folha, caule, raiz e total), área foliar, relação raiz/parte aérea e nitrogênio total nas mudas. Com base nessas variáveis, foram calculados os parâmetros fisiológicos de crescimento e a eficiência de uso de água, que foi obtida pela razão entre o total de biomassa seca acumulada e a evapotranspiração dos vasos no período, determinada através de pesagens diárias em balança de bancada. Ao final de 240 dias após a semeadura, Calophyllum brasiliense e Tabebuia impetiginosa apresentaram maior produção de biomassa seca total e Toona ciliata apresentou maior relação raiz/parte aérea. Não houve diferenças entre a taxa de crescimento relativo das espécies avaliadas. Eucalyptus urograndis, Toona ciliata e Calophyllum brasiliense apresentaram os maiores valores de razão de área foliar, Toona ciliata, Tabebuia impetiginosa e Eucalyptus urograndis apresentaram os maiores valores de área foliar específica, Eucalyptus urograndis e Calophyllum brasiliense apresentam os maiores valores para razão de massa foliar e Tabebuia impetiginosa, Toona ciliata e Eucalyptus urograndis apresentaram os maiores valores de taxa de assimilação líquida. Com base na quantificação do nitrogênio total, Tabebuia impetiginosa e Toona ciliata foram as espécies mais eficientes no uso do nitrogênio. Eucalyptus urograndis apresentou a maior evapotranspiração enquanto Calophyllum brasiliense e Tabebuia impetiginosa foram as espécies mais eficientes no uso de água.

Physiological Characteristics of Trees Recommended for the Phytoremediation of Soils Contaminated with Herbicides

ABSTRACT: Herbicides are inputs with a high volume of use in agricultural production systems for weed management; however, the environmental contamination they cause is a reality. The objective of this research was to evaluate the tolerance of tree species used for the phytoremediation of herbicides in the soil, to atrazine, clomazone and 2,4-D, through the evaluation of photosynthetic indices. Thus, a randomized block design experiment was conducted with four replications, in a 4 x 5 factorial arrangement, where the first factor represented the herbicides atrazine, clomazone and 2,4-D and the control treatment without herbicide (water). The second factor consisted in the use of pre-selected tree species for the phytoremediation of soils with residues of the products [Eremanthus crotonoides DC. (candeia), - Richeria grandis Vahl (richeria), Protium heptaphyllum (Aubl) Marchand, (breu-branco) Kielmeyera latrophyton Saddi, Kew Bull, (pau-santo) Calophyllum brasiliense Cambess (guanandi)]. The herbicides were applied through dishes placed under the culture containers of the plants, when they presented eight months of development. After 15 days from the herbicide application, the visual intoxication, stomatal conductance (Gs), transpiration rate (E), CO2 concentration in the substomatal chamber (Ci), and water use efficiency (WUE) were evaluated. The herbicides affected differently the physiological characteristics of the tree species; atrazine was the most harmful product. Individuals under the effect of 2,4-D and clomazone presented lower variation for their physiological characteristics, compared to the respective control treatments. Breu-branco, despite showing low visual intoxication provided by the herbicides, was the most affected species by the products. On the other hand, candeia was the most tolerant species to the action of the herbicides.

CARACTERÍSTICAS MORFOFISIOLÓGICAS FOLIARES E ESTADO NUTRICIONAL DE SEIS ESPÉCIES LENHOSAS EM FUNÇÃO DA DISPONIBILIDADE DE ÁGUA NO SOLO

A redução da disponibilidade hídrica causa efeitos na fisiologia e morfologia das plantas, sendo responsável por alterações no metabolismo, com implicações no desenvolvimento de plantas arbóreas. O objetivo deste trabalho foi avaliar a influência do estresse hídrico no crescimento foliar e estado nutricional em plantas adultas de gonçalo-alves (Astronium fraxinifolium), guanandi (Calophyllum brasiliense Cambess.), ipê-amarelo (Handroanthus serratifolius (Vahl.), ipê-rosa (Handroanthus impetiginosa (Mart.) Matos.), marupá (Simarouba amara Aubl.) e mogno (Swietenia macrophylla King.), cultivadas em condições de sequeiro e irrigadas, no perímetro irrigado do Baixo Acaraú, Ceará. O delineamento experimental adotado foi o de medidas repetidas no tempo, num esquema de parcelas subsubdivididas (6 x 2 x 2), sendo a parcela principal composta por seis espécies, a subparcela por dois regimes hídricos (irrigado e sequeiro) e a subsubparcela pelas épocas de avaliação. Foram determinadas concentrações foliares de N, P e K, além de área foliar específica (AFE), grau de suculência (GS), índice relativo de clorofila (IRC) e eficiência fotossintética no uso de N (A/N) e P (A/P), nas estações seca e chuvosa. Os resultados mostraram que o ipê-amarelo foi a espécie mais sensível quanto à variação das concentrações de N, P e K nas folhas em resposta à disponibilidade de água no solo. Quanto à AFE, ipê-amarelo, ipê-rosa e mogno foram mais sensíveis às condições de déficit hídrico extremo. A restrição hídrica no solo ocasiona a diminuição da suculência foliar no gonçalo-alves e no mogno. O IRC é diretamente afetado pelo déficit hídrico e está relacionado ao maior GS e à menor AFE. Quanto a A/N e A/P, o gonçalo-alves foi a espécie mais eficiente, não sendo afetado pelas condições de disponibilidade hídrica do solo.

A cost–benefit evaluation of direct seeding with and without protector for two native tree species in a tropical rainforest

A priority in restoration research is to seek methods that reach high levels of plant establishment at the lowest possible cost. Here, we test how direct seeding works with and without a plastic protector that covers seeds and seedlings in an early‐successional rainforest in Veracruz (Mexico). Two native species, Calophyllum brasiliense (barí) and Vochysia guatemalensis (corpo), at three topographic positions, were used. Germination rates with and without the protector were 84 versus 79% for C. brasiliense, and 98 versus 89% for V. guatemalensis, respectively. The protector significantly improved the germination only of V. guatemalensis. Plant survivorship of V. guatemalensis 27 months after seeding was significantly higher with the protector (78%) than without it (46%). For C. brasiliense, there were no differences in survivorship after 22 months with (61%) and without (54%) protector. In both species, the protector had no effect on height growth, which was significantly larger for seedlings located at the toeslope position. We developed a cost–benefit model that provides a threshold value at which the investment for protectors is justified by a resulting higher survivorship: If 27 months after seeding a treelet of V. guatemalensis is worth at least 0.83 USD on our sites, then the effect of the protector is worth the cost of its implementation (for C. brasiliense, survivorship was statistically undistinguishable with and without protector). We suggest that direct seeding with a plastic protector could be a promising alternative for forest restoration with suitable tree species.