Carapa Guianensis Research Articles

Inhibition of allergen-induced eosinophil recruitment by natural tetranortriterpenoids is mediated by the suppression of IL-5, CCL11/eotaxin and NFκB activation

The present study reports the anti-allergic activity of a group of six different tetranortriterpenoids (TNTP) isolated from the seeds of Carapa guianensis Aublet: 6a-acetoxygedunin, 7-deacetoxy-7-oxogedunin, andirobin, methyl angolensate, 6a-acetoxyepoxyazadiradione and gedunin. Oral pretreatment with TNTP significantly inhibited total leukocyte and eosinophil accumulation in C57BL/10 mice pleural cavities 24 h after the intrathoracic (i.t.) injection of ovalbumin (OVA), but had no effect on CD4, CD8 or γδ T lymphocyte accumulation. Pleural washes recovered from 6 h OVA-stimulated mice (OPW) pretreated with TNTP failed to induce shape change in eosinophil in vitro, indicating the inhibition of eosinophilotactic chemokines by TNTP. In accordance with such results, ELISA assays showed decreased levels of CCL11/eotaxin and IL-5 in OPW recovered from TNTP pretreated mice within 6 h. TNTP oral pretreatment inhibited nuclear factor-κB (NFκB) translocation into the nucleus in pleural leukocytes recovered from previously sensitized mice after antigenic challenge. In addition, the incubation of splenocytes recovered from previously sensitized mice with TNTP also inhibited NFκB activation after OVA stimulation. Taken together, these results indicate that the inhibition of allergic eosinophilia by TNTP is correlated with the inhibition of CCL11/eotaxin and IL-5 generation through NFκB signaling pathway impairment in mice.

Morfologia da copa para avaliar o espaço vital de quatro espécies nativas da Amazônia

O objetivo deste trabalho foi o de definir diretrizes para o desbaste de quatro espécies nativas: a castanha-do-pará ou castanheira-do-brasil (Bertholletia excelsa), a andiroba (Carapa guianensis), o ipê-roxo (Tabebuia avellanedae) e o jatobá (Hymenaea courbaril), plantadas em plantios homogêneos no Estado de Roraima. Foi feita a análise das relações entre os principais índices morfométricos da copa e o crescimento em diâmetro e altura; para isso foram medidos o diâmetro à altura do peito, altura total, altura de inserção e diâmetro da copa de 87 árvores. Na análise dos parâmetros de copa, a castanheira-do-brasil demonstrou superioridade em diâmetro e área, o que indica que essa espécie necessita de um maior espaço vital e maiores espaçamentos iniciais; no entanto, sua copa foi menos eficiente em manter um mesmo incremento médio anual em diâmetro.

Anti-allergic effects of natural tetranortriterpenoids isolated from Carapa guianensis Aublet on allergen-induced vascular permeability and hyperalgesia

We investigated the anti-allergic and analgesic properties of an oil and a derived fraction of tetranortriterpenoids (TNTP) obtained from the seeds of Carapa guianensis Aublet. Pleurisy, paw and ear edema were induced in Swiss and C57/Bl10 mice mice, whereas thermal hyperalgesia was assessed in Wistar rats (n = 6-10 per group). Values of p < 0.05 were regarded as significant. C. guianensis oil (100 to 400 mg/kg, p.o.) and TNTP (12.5 to 100 mg/kg, p.o.) inhibited pleural exudation, paw and ear edema induced by ovalbumin (OVA) in sensitized mice. TNTP (12.5 to 100 mg/kg, p.o.) also inhibited paw edema induced by histamine, PAF and bradykinin. TNTP (100 mg/kg, p.o.) inhibited prostaglandin E(2) generation in the pleural cavity in response to antigenic challenge. Moreover, C. guianensis oil (100 to 400 mg/kg) and TNTP (12.5 to 100 mg/kg) decreased OVA- and histamine-induced hyperalgesia. Taken together, these findings demonstrate the anti-edematogenic and analgesic effects of C. guianensis oil, and points out TNTP as the responsible bioactive compounds.

Development of microsatellite markers for Carapa guianensis (Aublet), a tree species from the Amazon forest

Abstract Carapa guianensis is a timber species found in Central America and the north of South America. We have developed microsatellite primers which will allow analysis of gene flow and population genetic structure in natural populations of this tree species. Polymorphism of five microsatellite loci was evaluated using a total of 12 adult trees from a natural population. An average of 4.2 alleles per locus was detected, and expected heterozygosity ranging from 0.397 to 0.806. These loci are being used for genetic population analysis in a managed forest in the state of Pará, in Amazonian Brazil, as part of the Dendrogene project.

Comparative study of the topical effectiveness of the andiroba oil (Carapa guianensis) and DEET 50% as repellent for Aedes sp

DEET (N,N-diethyl-3-methylbenzamide) is nowadays the most effective mosquito repellent available, however, its use can present some topical and systemic side effects. Some botanical compositions, as Andiroba (Carapa guianensis), have been proved repellent properties at low cost and toxicity. An experimental study was driven involving four volunteers submitting their forearms covered with Andiroba oil at 100%, DEET 50%, refined soy oil, Andiroba oil 15% and in the absence of products, directly to healthy females of Aedes sp. The times of first and third bites were checked. The results showed that the median of the first bite without any product was 17.5s and the third bite, 40.0s. In the soy oil, the bites happened in 60.0s and 101.5s, in the presence of Andiroba oil 100%, in 56.0s and 142.5s and in Andiroba oil 15%, in 63.0s and 97.5s. The volunteers using DEET 50% had not received bites after 3600s in most of the experiments (p < 0.001 Wilcoxon). Pure Andiroba oil compared to the soy oil, forearm without product and Andiroba oil 15%, showed discreet superiority (p < 0.001 Wilcoxon). Our conclusion is that this study demonstrated that the pure Andiroba oil presents discreet repellent effect against bite of Aedes sp., being significantly inferior to DEET 50%.

Effect of earthworm addition on soil nitrogen availability, microbial biomass and litter decomposition in mesocosms

The aim of the study was to determine the effect of adding two tropical earthworm species, Rhinodrilus contortus and Pontoscolex corethrurus, to mesocosms on the availability of mineral N (NH4+ and NO3−concentrations), soil microbial biomass (bio-N), and the decomposition rates of three contrasting leaf litter species, in a glasshouse experiment. The mesocosms were filled with forest soil and covered with a layer of leaf litter differing in nutritional quality: (1) Hevea brasiliensis (C/N=27); (2) Carapa guianensis (C/N=32); (3) Vismia sp., the dominant tree species in the second growth forest (control, C/N= 42); and, (4) a mixture of the former three leaf species, in equal proportions (C/N=34). At the end of the 97-day experiment, the soil mineral N concentrations, bio-N, and leaf litter weight loss were determined. Both earthworm species showed significant effects on the concentrations of soil NO3−(p<0.01) and NH4+ (p<0.05). Bio-N was always greater in the mesocosms with earthworms (especially with R. contortus) and in the mesocosms with leaf litter of H. brasiliensis (6 µg N g−1 soil), the faster decomposing species, than in the other treatments (0.1–1.6 µg N g−1). Thus, earthworm activity increased soil mineral-N concentrations, possibly due to the consumption of soil microbial biomass, which can speed turnover and mineralization of microbial tissues. No significant differences in decomposition rate were found between the mesocosms with and without earthworms, suggesting that experiments lasting longer are needed to determine the effect of earthworms on litter decomposition rates.

Determinação de compostos de massa molecular alta em folhas de plantas da Amazônia

The fractIons of dichloromethane extracts of leaves from andiroba (Carapa guianensis - Meliaceae), caapi (Banisteriopsis caapi - Malpighiaceae), cocoa (Theobroma cacao - Sterculiaceae), Brazil nut (Bertholletia excelsa - Lecytidaceae), cupuacu (Theobroma grandiflorum - Sterculiaceae), marupa (Simaruba amara - Simaroubaceae) and rubber tree (Hevea brasiliensis - Euphorbiaceae), were analyzed by HT-HRGC and HT-HRGC-MS. Esters of homologous series of fatty acids and long chain alcohols, phytol, amyrines and tocopherols were characterized. The characterization of the compounds was based mainly in mass spectra data and in addition by usual spectrometric data (1H and 13C NMR, IR).

Utilization of metal complexes as catalysts in the transesterification of Brazilian vegetable oils with different alcohols

Abstract This article reports the use of Sn(3-hydroxy-2-methyl-4-pyrone) 2 (H 2 O) 2 ( 1 ), Pb(3-hydroxy-2-methyl-4-pyrone) 2 (H 2 O) 2 ( 2 ), and Zn(3-hydroxy-2-methyl-4-pyrone) 2 (H 2 O) 2 ( 3 ) as catalysts in the transesterification reaction of different alkyl-chain triglycerides and alcohols. The methanolysis of native oils from Brazilian’s Savannah and Amazonian regions, such as Andiroba ( Carapa guianensis ), Babassu ( Orbignia sp. ), Cumaru ( Dipteryx odorata ), Palm tree ( Elaeis sp. ), Piqui ( Caryocar sp. ), and Soybean oil as well as the alcoholysis of Soybean oil with several alcohols (ethanol, propanol, iso -propanol, n -butanol, terc -butanol and cyclo -hexanol) was studied. Activities of the tin and lead pyrone complexes were observed in all the alcohol studies. For linear alcohols, the reaction activities decrease with increasing carbonic chain length. It was also shown that the catalytic activities are higher when vegetable oil with short chain fatty acids or with a high unsaturated degree and short and linear chain alcohols are used.

Soil microbial activities in tree-based cropping systems and natural forests of the Central Amazon, Brazil

Little information is available about the factors controlling soil C and N transformations in natural tropical forests and tree-based cropping systems. The aim of this work was to study the effects of single trees on soil microbiological activities from plantations of timber and non-timber species as well as species of primary and secondary forests in the Central Amazon. Soil samples were taken in the primary forest under Oenocarpus bacaba and Eschweilera spp., in secondary regrowth with Vismia spp., under two non-timber tree species (Bixa orellana L. and Theobroma grandiflorum Willd.), and two species planted for wood production (Carapa guianensis Aubl. and Ceiba pentandra). In these soils, net N mineralization, net nitrification, denitrification potential, basal and substrate-induced respiration rates were studied under standardized soil moisture and temperature conditions. Individual tree species more strongly affected N transformations, particularly net nitrification, than C respiration. Our results suggest that soil C respiration can be affected by tree species if inorganic N becomes a limiting factor. We found a strong correlation among almost all microbiological processes suggesting close inter-relationship between C and N transformations in the studied soils. Correlation analysis between soil chemical properties and microbiological activities suggest that such strong inter-relationships are likely due to competition between the denitrifying and C-mineralizing communities for NO3−, which might be an important N source for the microbial population in the studied soils.

Seed germination during floatation and seedling growth of Carapa guianensis, a tree from flood-prone forests of the Amazon

Carapa guianensis Aubl. (Meliaceae), a hard wood tree from the Brazilian Amazon, has large recalcitrant seeds that can germinate and establish in both flood-free (terra-firme) and flood-prone (varzea) forests. These seeds, although large, can float. This study was designed to experimentally examine seed longevity under floating conditions ex-situ and its effects on subsequent germination and seedling growth. Many seeds germinated while floating, and radicle protrusion occurred from 3 to 42 d after the start of the floating treatment (tap water, room temperature 20–30 °C). Shoots of newly germinated floating seedlings may elongate up to 37.0 cm in 20 d without loss of viability. Epicotyl and first leaf emergence were delayed by floating. Seeds that did not germinate while floating were then placed on vermiculite and watered daily, where many seeds resumed germination. Germination during and after floating was affected by the length of the floating treatment: 88% germinated after 1 mo, 82% germinated after 2 mo and 70% germinated after 2.5 mo. These results indicate that Carapa guianensis has physiological variation regarding dormancy in response to seed floatation. The fact that floatation induces dormancy in recalcitrant seeds of this economically important species can be relevant to initiatives of ex situ storage of seeds.

Regulation of xylem sap flow in an evergreen, a semi-deciduous, and a deciduous Meliaceae species from the Amazon

The significance of phenological characteristics, stomatal conductance of the leaves, and stem water storage fluctuations for the regulation of xylem sap flow in an evergreen (Carapa guianensis Aubl.), in a semi-deciduous (Swietenia macrophylla King), and in a deciduous (Cedrela odorata L.) Meliaceae species was studied in a 7-year-old plantation near Manaus, Brazil. The study responds to the increasing demand for knowledge on the water relations of highly exploited timber trees of the Amazon. Xylem sap flow measurements indicated that the daily sap flow of Carapa (3.8 l day–1 tree–1 to 16.4 l day–1 tree–1) exceeded the daily sap flow of Swietenia (2.4 l day–1 tree–1 to 7.0 l day–1 tree–1) and Cedrela (1.6 l day–1 tree–1 to 11.6 l day–1 tree–1) during the entire year, although the highest flux densities were measured in Cedrela. The decrease in xylem sap flow observed in periods with low soil water potentials and high atmospheric vapor saturation deficits was more pronounced in the deciduous (Cedrela) and semi-deciduous species (Swietenia) than the evergreen species (Carapa). Carapa, which has the highest daily sap flow, had the highest biomass and sapwood portion. The high flux densities measured in Cedrela most likely result from the large earlywood vessels in this species. The seasonal variation of xylem sap flow of the three species was correlated with the stomatal conductance of the leaves measured by infiltration experiments. Stem water storage fluctuations in Carapa and Swietenia were predominantly due to transpiration; in Cedrela it was predominantly due to evaporative water loss on the stem surface during dry periods.

Nutrient fluxes and growth of Carapa guianensis Aubl. in two plantation systems in the central Amazon

The K, Mg, and P fluxes as well as the growth dynamics of the important timber tree Carapa guianensis Aubl. were compared in a monoculture and in an enrichment plantation on a “terra firme” site near Manaus, central Amazon. During the 7 years experimental period, the K, Mg, and P fluxes and the balance of the soil were quantified for monthly intervals. The nutrient input into the soil was calculated from the wet and dry deposition as well as from litter decomposition. The nutrient output out of the soil was calculated from the net nutrient uptake of the vegetation and the nutrient leaching from the soil. The growth dynamics of the planted trees were studied by means of biomass data obtained from dendrometric measurements and total tree harvesting. After 7 years of growth, the K, Mg, and P balance of the soil of the enrichment plantation was stabilised, whereas a significant deficit of the K, Mg, and P balance of the soil of the monoculture became obvious, caused by high leaching of K and Mg from the soil and low litter decomposition rates. Due to strong competition during the first 5 years of growth, a reduced biomass production of the planted Carapa trees was found in the enrichment plantation compared to trees grown in the monoculture. After that period tree growth was strongly reduced in the monoculture, whereas after 7 years, growth of Carapa grown in the enrichment plantation was still steady. From this study, it was concluded that due to the balanced K, P, and Mg input and output of the soil and more sustainable growth of the planted trees in the enrichment plantation compared to the traditional monoculture, the cultivation of Carapa for timber production is recommended in diverse plantations, such as enrichment plantations on this study site.

Soil carbon stocks after forest conversion to tree plantations in lowland Amazonia, Brazil

The large-scale conversion of Amazonian forest to other land-uses is altering carbon (C) stocks in this important eco-region, and these changes will in turn influence global C cycling. In this study, we evaluated changes of forest floor and surface soil C storage caused by converting primary Amazonian forest to tree plantations at the Curuá-Una Forest Reserve, Pará, Brazil. The plantations were established between 1959 and 1973 and they consisted of replicated plots of Pinus caribaea var. hondurensis Barrett and Golfari, Carapa guianensis Aubl., Euxylophora paraensis Hub., and a Leguminosae combination ( Parkia multijuga Benth., Dinizia excelsa Ducke, Dalbergia nigra Fr. All. In surface soils (0–20 cm), mean C stocks ranged from 7 ( P. caribaea) to 11 kg m −2 ( E. paraensis). Fine litter C inputs ranged from 380 g m −2 ( E. paraensis) to 513 g m −2 ( P. caribaea), and forest floor C stocks (fine material) ranged from 359 ( E. paraensis) to 542 g m −2 ( P. caribaea). P. caribaea had the smallest fine root biomass–C (≤2 mm diameter) in the forest floor and surface soils (101 g m −2). Relative to adjacent terra firme forest, total C stocks in the surface mineral soil, forest floor, and fine roots (live+dead) in the plantations ranged from a net decrease of 13% ( P. caribaea) to a net increase of 7% ( E. paraensis).

Water balance and water potentials of a monoculture and an enrichment plantation of Carapa guianensis Aubl. in the Central Amazon

The water balance and the water potential of the soil and the atmosphere as well as the leaf water potential of an 1-year-, a 5-year- and an 8-year-old monoculture and enrichment plantation of the important timber tree Carapa guianensis Aubl. were compared on a “terra firme” site near Manaus, Central Amazon. The water balances of the plantations were quantified in monthly intervals. As to quantify the water input into the plantations, the precipitation, the interception, the throughfall, and the stemflow were measured. The transpiration of the vegetation was studied by means of xylem flux measurements. The water runthrough in the soil was quantified by means of tensiometer measurements carried out in 5, 15, 35, 65 and 125 cm depths and the pF relationship of the soil studied in the laboratory. The evaporation from the soil was calculated as the difference between the water input, the transpiration and the water runthrough in the soil. The water potential of the atmosphere was monitored continuously during the experiment. The water potential of the leaves of the planted Carapa trees was quantified by means of a Scholander pressure bomb. The annual precipitation varied between 2451 and 3193 mm with maximum values from December until May. In the 1-year- and the 5-year-old monoculture high interception (up to 40% of the precipitation) of the cover crops was found. During the wet season sequestration of water from the air contributed significantly to the water balance of the enrichment plantation. In the monoculture transpiration contributed with 21–27% to the water balance of the plantation, while approximately 50% of the water balance of the enrichment plantation was caused by transpiration. In addition high water runthrough (24–31% of precipitation input) was found in the monoculture compared to the enrichment plantation (7–10% of precipitation input). The intra-annual variation of the water fluxes was lower in the enrichment plantation compared to the monoculture. Consequently, the water potential of the leaves of the planted Carapa trees grown in the enrichment plantation was lower compared to trees grown in the monoculture, indicating that the stabilisation of the water balance in the enrichment plantation caused more favourable conditions for the water supply of the planted Carapa trees.

Tree Seed Fate in a Logged and Fragmented Forest Landscape, Northeastern Costa Rica1

We compared the seed fate of two animal-dispersed, large-seeded timber species (Dipteryx panamensis [Fabaceae] and Carapa guianensis [Meliaceae]) in logged and fragmented forests with that for continuous forest in northeastern Costa Rica. For both species, we quantified rates of seed removal (an index of vertebrate predation) and the fate of dispersed seeds (those carried away from their original location that either germinated or were not subsequently removed within three months). We predicted that (1) fewer seeds would be dispersed by vertebrates in fragmented forest than in continuous forest due to low population abundances after hunting and/or loss of suitable habitat, and (2) seed predation rates would be higher in forest fragments than in continuous forest due to high abundance of small-bodied seed consumers. We compared three forest fragments currently managed for timber (140–350 ha) and a large reserve of continuous forest (La Selva, 1500 ha and connected to a national park). An exclusion experiment was performed (seeds placed in the open vs. seeds within semipermeable wire cages; 5 cm mesh size) to evaluate the relative roles of large and small animals on seed removal. Seed germination capacity did not differ among all four sites for both species. Removal of Dipteryx seeds was higher in forest fragments (50% removal within 10 days and related to the activity of small rodents) compared to La Selva (50% removal after 50 days). Also, more Dipteryx seeds were dispersed at La Selva than in fragmented forests. Contrary to our predictions, removal of Carapa seeds was equally high among all four sites, and there was a trend for more seeds of Carapa to be dispersed in fragments than in La Selva. Our results suggest that fragmentation effects on tree seed fate may be specific to species in question and contingent on the animal biota involved, and that management strategies for timber production based on regeneration from seed may differ between forest patches and extensive forests.

FORMATION OF INCREMENT ZONES AND INTRAANNUAL GROWTH DYNAMICS IN THE XYLEM OF SWIETENIA MACROPHYLLA, CARAPA GUIANENSIS, AND CEDRELA ODORATA (MELIACEAE)

The pattern of growth increment zones, the cambial growth dynamics and the structural variation in wood formation of Swietenia macrophylla King, Carapa guianensis Aubl., and Cedrela odorata L. (Meliaceae) were investigated in order to understand the relationship of site conditions and sustainable growth in Central Amazonian plantations. Trees were available from 8-, 17-, 23-, and 57-year-old plantations, and from primary forests in Manaus (Amazônia), Santarem (Pará), and Aripuanã (Mato Grosso). The wood anatomical structure and the annual increments of 61 Swietenia, 94 Carapa, and 89 Cedrela trees were studied for different tree heights. The curves of annual increments were cross-dated and tested for synchronisation. The cambial growth dynamics of up to 52 trees per species were dated by means of dendrometer measurements, monthly labelling by pinmarkers, and extracted cambium samples investigated using a microscope. The intraannual course of the growth and structural variation was compared with the water supply of the soil and insect attacks (Hypsipyla grandella (Zeller) Lep.). In Swietenia and Carapa parenchyma and vessel bands as well as bands of resin canals were observed. Within the xylem of Cedrela, alternating bands of fibres and vessels surrounded by paratracheal parenchyma were found; bands of resin canals were only occasional. In the juvenile wood of Swietenia and Carapa no synchronization of the increment curves was possible, whereas the increment curves obtained in the juvenile wood of Cedrela showed parallel run in growth. The increment curves obtained in adult wood of Swietenia and Cedrela indicate an annual formation of increment zones, whereas the number of increment zones in the xylem of Carapa was approximately 50% higher than the tree age (years) indicating that the growth increments of Carapa also were not annual during the adult phase of growth. The study of the intraannual growth dynamics of the trees showed that the formation of parenchyma bands in Swietenia is induced by dry periods before a cambial dormancy. The formation of parenchyma bands of Carapa was induced by extremely dry and extremely wet periods before a cambial dormancy, whereas fibre bands in Cedrela were induced by dry periods before a cambial dormancy and the formation of vessel bands embedded in paratracheal parenchyma was induced by wet periods after a cambial dormancy. In addition, insect attack (Hypsipyla grandella) induced locally restricted formation of parenchyma bands and bands of resin canals in Swietenia, Carapa and Cedrela.

NOTES ON THE NATURAL HISTORY OF THE PALE-MANDIBLED ARAÇARI

The little-known Pale-mandibled Araçari is endemic to wet forests of western Ecuador. I quantified population density, feeding ecology, reproductive biology, and vocalizations. Population density in the study area was one group (nine individuals) per 333 ha. They were observed to consume fruits of 34 species of plants, of which Lauraceae and Palmae were the most important. Pale-mandibled Araçaris fed their young fruits from at least eight species of plants, insects from five orders, adult and nestling birds, and bird eggs. Nests were made in cavities within live trees, typically Carapa guianensis, and clutches consisted of at least two eggs. At one nest, incubation lasted approximately 17 d. Nestling care in one nest lasted at least 44 d, and was shared by the female, the male and at least one helper. Pale-mandibled Aracaris roosted in groups of up to seven individuals. Ninety-five percent of primary forest in the range of this species had been cut by 1988, and less than 1% of its original habitat lies within protected areas.

The effects of desiccation on seeds of Acer saccharinum and Aesculus pavia: recalcitrance in temperate tree seeds

This study was undertaken to determine how the results from lipid, moisture, and differential scanning calorimetry analyses conducted on silver maple (Aceraceae: Acer saccharinum L.) and red buckeye (Hippocastanaceae: Aesculus pavia L.) compared with those obtained from previous studies on white and water oaks (Fagaceae: Quercus alba and Q. nigra), and the tropical zone species American muskwood (Meliaceae: Guarea guidonia) and carapa (Meliaceae: Carapa guianensis). Seeds were air-dried at room temperature for 9–11 days. At intervals, germination was tested, moisture determined, and lipids extracted. It was found that, like the other recalcitrant seeds, (1) viability was greatly reduced or lost after 11 days of drying, (2) percentage changes in individual fatty acids were not related to seed viability, and (3) results from the differential scanning calorimetry studies revealed a strong relationship between enthalpy/onset data from the embryo and cotyledon tissues and loss of viability. Also, silver maple seeds experienced a 50% reduction in viability by day 5 of drying and retained an axis moisture content over 25% throughout the experiment. However, unlike the other recalcitrant seeds surveyed, both silver maple and red buckeye had a significant reduction in the total amount (mg/g) of cotyledon lipids as the experiment progressed. However, no decrease in the unsaturated/saturated fatty acid ratio was found, so we conclude that in these species lipid peroxidation is not a marker of declining seed viability. Also, red buckeye seeds did not lose 50% viability until after day 8 of the experiment, and axis moisture content fell well below 20% as the seeds dried.

COMPARISON OF GROWTH DYNAMICS AND WOOD CHARACTERISTICS OF PLANTATION-GROWN AND PRIMARY FOREST CARAPA GUIANENSIS IN CENTRAL AMAZONIA

This study responds to the demand for recultivation of degraded land areas in Central Amazonia and the desire to add long-lived trees for high-quality timber production to polyculture plantation systems. Carapa guianensis Aubl. from two monocultures (ages 4 and 17 years) and a primary forest were studied. The growth dynamics of the 4-yearold trees revealed 11 to 15 increments marked by tangentially oriented vessel rows. By the 5th year, parenchyma bands indicate mature wood. Monthly labelling by pin-markers revealed short dormancy periods during the dry season. The early formation of mature wood is shown by the pattern of percentage composition of vessels, fibres, and parenchyma. Fibre length reaches its plateau of 1.45–1.59 mm at about four years. Fibre lengths and average density (0.63 g /cm3) of plantation-grown trees correspond to those of primary forest trees. According to this study, Carapa guianensis can be recommended for plantations in order to produce high-quality timber with a decorative heartwood.

Population structure delineated with microsatellite markers in fragmented populations of a tropical tree, carapa guianensis (Meliaceae)

Deforestation and selective logging in the tropics may have serious consequences on genetic processes in tropical tree populations, affecting long-term survival of a given species as well as tropical forest communities. Because understanding the effects of human-induced changes on genetic processes is of utmost importance in formulating sound conservation and management plans for tropical forest communities, we developed microsatellite or simple sequence repeat (SSR) markers for the tropical tree Carapa guianensis (Meliaceae) and assessed the polymorphism of SSRs in adult and sapling populations in a large contiguous forest and in selectively logged and fragmented forests. The number of alleles in polymorphic loci ranged between 4 and 28. No inbreeding was detected in saplings or adult cohorts, but the allelic richness was lower in the sapling cohort of the isolated fragment. Genetic distances, Nei's D and (delta&mgr;)2, and RST values among saplings were greater than among adult cohorts, suggesting restriction of gene flow due to deforestation and habitat fragmentation. These SSR loci may be used to address many related questions regarding the population and conservation genetics of tropical trees.