Lúcia Helena de Oliveira Wadt

Liana loads and their association with Bertholletia excelsa fruit and nut production, diameter growth and crown attributes

We investigated the association between lianas and Bertholletia excelsa (Brazil nut), a long-lived, emergent tree of significant ecological and economic importance in Amazonia. Our objectives were: (1) to determine the relationship between crown liana load and liana number, basal area, and origin in relation to the B. excelsa host; and (2) to determine the relationship between liana load and B. excelsa fruit and nut production, diameter growth, and crown form, position and area. One hundred and forty trees (≥ 50 cm dbh) were selected with representatives of 10 diameter classes and four liana load categories. To quantify fruit and nut production, fruit counts and nut fresh weights per tree were measured in 2002 and 2003, and annual diameter growth was quantified using dendrometer bands. Trees with lianas produced significantly fewer fruits and had reduced nut fresh weights than liana-free trees. Trees with the most extensive liana loads (> 75% crown coverage) were 10.2 times more likely to have crown forms categorized as less than half-crowns or few branches than trees with reduced liana loads. No statistically significant relationship was found between liana load and tree diameter growth. Results suggest that liana cutting might increase B. excelsa fecundity and commercial nut yields.

Testing a silvicultural recommendation: Brazil nut responses 10 years after liana cutting

Summary 1. Lianas or woody vines can be detrimental to the trees that support them. Research on liana cutting for tropical timber management has demonstrated positive yet costly benefits, but liana cutting to enhance commercial outputs of nontimber forest products has not been examined. We implemented a controlled experiment to quantify the effects of cutting lianas on Brazil nut Bertholletia excelsa Bonpl. fecundity. 2. We conducted our 10-year experiment in a Brazilian extractive reserve where local harvesters collect fruits from this Amazonian canopy-emergent species as part of their forest-based livelihood system. We cut 454 lianas with a total basal area of 241 m 2 from 78 of 138 host trees ≥50 cm diameter at breast height. 3. Treated trees were significantly better producers 3 ½ years after liana cutting, and these differences increased dramatically in subsequent years, with consistent proportionally higher production in treated versus untreated individuals. 4. The number of lianas rooted within 5 m of the host tree significantly explained production levels, suggesting both above- and below-ground liana–host tree competition. Once host crowns were liana-free, branch regrowth was highly visible, particularly in heavily infested trees, and crown reassessments suggested that liana cutting improved crown form. Additionally, liana cutting may induce some nonproducing trees to become producers and may circumvent mortality of trees heavily infested with lianas (> 75% crown covered). 5. Liana removal can be implemented easily when harvesting Brazil nut fruits. Only lianas associated with B. excelsa trees should be cut to conserve liana ecosystem functions. 6. Synthesis and applications. We quantified effects of liana cutting on Brazil nut host tree fecundity and provided estimates of increased commercial yields. Our long-term (10-year) study permits understanding of biological variation and informs related management decisions. Findings suggest that liana cutting reduces above- and below-ground competition with individual trees, ultimately allowing mature host crowns to recover such that 9–10 years after liana cutting, treated trees produced on average three times more fruits than untreated trees. Application of liana cutting to other tropical species would likely boost fruit and seed production, increase host tree fecundity and potentially enhance future recruitment.

Potencial de produção de óleo-resina de copaíba (Copaifera spp) de populações naturais do sudoeste da Amazônia

O potencial de producao de oleo-resina extraido de Copaifera spp foi avaliado em duas populacoes naturais do sudoeste da Amazonia brasileira (municipios de Tarauaca e Xapuri), nos anos de 2000 e 2001. Foram selecionadas 388 arvores adultas de copaibas das duas populacoes, sendo identificados em cada arvore o diâmetro a altura do peito (DAP), a producao de oleo-resina, a posicao da arvore no relevo local (baixio ou terra firme) e a tipologia florestal local (floresta aberta ou densa), alem do nome regional da copaiba, com base em caracteristicas morfologicas da casca: Copaifera reticulata: copaiba-branca, vermelha, amarela e preta e Copaifera paupera: mari-mari. Os resultados indicam que a copaiba mari-mari possui maior proporcao de individuos produtivos (80%), enquanto os demais morfotipos apresentaram apenas de 22 a 40% de seus individuos produtivos. Com relacao a todas as arvores amostradas, a producao de oleo-resina variou de 0 a 18 L arvore-1, com a copaiba mari-mari tendo a maior producao media (1,33 L arvore-1), porem sem diferir significativamente dos demais morfotipos. Apos excluir da analise as arvores nao produtivas, a copaiba-preta apresentou significativamente a maior producao media de oleo-resina (2,92 L arvore-1). A tipologia florestal, posicao da arvore no relevo e o DAP nao se mostraram relacionados a producao de oleo-resina.

Estrutura genética e sistema de acasalamento de Piper hispidinervum

Long pepper (Piper hispidinervum C. DC.) is a small tree with high commercial value found in areas under anthropic influence in the State of Acre, Brazil. The genetic structure and mating system of P. hispidinervum were evaluated using RAPD markers. The genetic diversity within and between natural populations were evaluated in 13 populations in the Basin Acre River - Western Brazilian Amazon. Twenty five open-pollinating families in a population located in Assis Brasil were evaluated to estimate the preferential crossing rate. Genetic diversity was observed, revealing that this species is spatially structured according to a pattern of isolation by distance. Most of the genetic variability was found within populations, and the variation between populations was also high (θP = 0.28). Two distinct groups were formed, based on genetic distances (φST), representing the Upper Acre and Lower Acre watersheds. By AMOVA, 20.61% of the total variability occurs between those two watershed regions. The multilocus crossing rate was estimated at 1.033, the estimate of the inbreeding coefficient (F) did not vary from zero, and the crosses preferentially occurred between unrelated individuals.

Genetic diversity of "Pimenta Longa" genotypes (Piper spp., Piperaceae) of the Embrapa Acre germplasm collection

The commonly known Pimenta longa is a commercially valuable natural resource found wild in Acre, Brazil. Specifically, three Piperaceae species with contested taxonomic status were studied, Piper hispidinervum, Piper aduncum, and Piper hispidum, to assesses the inter- and intra-specific genetic relationship of 49 Piper genotypes kept in the Pimenta longa germplasm collection at Embrapa Acre, using sixty six Random Amplified Polymorphic DNA (RAPD) markers. The DNA polymorphism level detected was high (96.97%), but the marker frequencies for each species showed polymorphism levels of 79.4% for Piper hispidinervum and 5.3% for P. aduncum. The genetic similarity clustering analysis resulted in three distinct groups corresponding to Piper hispidinervum, Piper aduncum, and Piper hispidum. Four and nine characteristic RAPD markers were identified for P. hispidinervum and P. aduncum, respectively, supporting the existence of two separate species. However, six genotypes collected in Tarauaca county formed a distinct subgroup within the P. hispidinervum group and may be considered as an ecotype of this species or an intermediate between the P. hispidinervum and P. aduncum groups. More extensive sampling of both P. hispidinervum and P. aduncum populations throughout the region are needed to further establish their relation and its implication for breeding efforts.

Diversidade genética de populações de andiroba no Baixo Acre

Abstract€–€The€objective of this work was to evaluate the genetic diversity of two Carapa guianensis Aubl.(crabwood) populations, in the S tate of Acre, Brazil, and to compare the diversity estimations with those obtainedin other populations of the species (in Brazil: Flona Tapajos, PA, Porto Acre, AC; and in Costa Rica). Seventy-seven individuals were assessed using seven polymorphic microsatellite loci. Fifty-one alleles were observed inthe two populations, in which the effective number of alleles per locus (A ^ e €=€3.2) was lower than the averagenumber of alleles per locus (A ^ €=€7.3), which indicates a high number of low frequency alleles. The estimatedf ^ values did not differ from zero, showing that inbreeding does not occur in these populations. The apparentoutcrossing rate was high for both populations ( t ^ a €=€1.1 1 in Porto Acre population, and t ^ a €=€0.88 in Rio Branco),indicating that this species reproduces by outcrossing. Comparing the estimates of A ^ e , H ^

Genetic structure of Bertholletia excelsa populations from the Amazon at different spatial scales

Population genetic structure and genetic diversity levels are important issues to understand population dynamics and to guide forest management plans. The Brazil nut tree (Bertholletia excelsa Bonpl.) is an endemic species, widely distributed through Amazonian upland forests and also an important species for the local extractive economy. Our aim was to analyze the genetic structure of Brazil nut trees at both fine and large scales throughout the Amazon Basin, contributing to the knowledge base on this species and to generate information to support plans for its conservation. We genotyped individuals from nine sites distributed in five regions of the Brazilian Amazon using 11 microsatellite loci. We found an excess of heterozygotes in most populations, with significant negative inbreeding coefficients (f) for five of them and the fine-scale structure, when present, was very small. These results, as a consequence of self-incompatibility, indicate that conservation plans for B. excelsa must include the maintenance of genetic diversity within populations to ensure viable amounts of seeds for both economic purposes and for the local persistence of the species.

Pollen and seed flow patterns of Carapa guianensis Aublet. (Meliaceae) in two types of Amazonian forest

Various factors affect spatial genetic structure in plant populations, including adult density and primary and secondary seed dispersal mechanisms. We evaluated pollen and seed dispersal distances and spatial genetic structure of Carapa guianensis Aublet. (Meliaceae) in occasionally inundated and terra firme forest environments that differed in tree densities and secondary seed dispersal agents. We used parentage analysis to obtain contemporary gene flow estimates and assessed the spatial genetic structure of adults and juveniles. Despite the higher density of adults (diameter at breast height ≥ 25 cm) and spatial aggregation in occasionally inundated forest, the average pollen dispersal distance was similar in both types of forest (195 ± 106 m in terra firme and 175 ± 87 m in occasionally inundated plots). Higher seed flow rates (36.7% of juveniles were from outside the plot) and distances (155 ± 84 m) were found in terra firme compared to the occasionally inundated plot (25.4% and 114 ± 69 m). There was a weak spatial genetic structure in juveniles and in terra firme adults. These results indicate that inundation may not have had a significant role in seed dispersal in the occasionally inundated plot, probably because of the higher levels of seedling mortality.

Control of Carapa guianensis phenology and seed production at multiple scales: a five-year study exploring the influences of tree attributes, habitat heterogeneity and climate cues

During 5 y, we monitored reproductive activity and seed production of Carapa guianensis in two forest types to test the hypothesis that seed production is influenced by multiple factors across scales (regional climatic cues, local habitat heterogeneity and individual tree attributes). Variability in seed production was moderate at the population (CVp =1.25)andindividuallevel(xCVi =1.24).AmixedmodelwithaPoissonregressionrevealedthatseedproduction was explained by variables at all scales. Total seed production was significantly higher in occasionally inundated forests. Diameter at breast height, dbh 2 , crown cross-sectional area, liana load, density, dry-season rainfall and mean maximum temperature were also significant in explaining seed production variation. Seed production increased with dbh until 40-50 cm, then decreased. Liana load demonstrated a negative relationship with seed production, but only in terra firme forests. Climatic cues (rainfall and temperature parameters) were central to setting overall patterns in reproductive activity and seemed to best explain why years with high seed production were consistent across the two forest types (habitats) examined. Dry-season rainfall was positively correlated with seed production.

Mating system variation among populations, individuals and within and among fruits in Bertholletia excelsa

Abstract The aim of this study was to investigate variation in mating system among three Brazilian Amazon populations of the tree Bertholletia excelsa with different levels of anthropogenic interventions. We collected open-pollinated seeds from one natural population, remnant trees dispersed in a pasture, and trees from a plantation. Outcrossing rate not varied among the populations and indicates that all seeds were originated from outcrossing (tm=1.0). Mating among relatives was significant higher in the plantation than forest and pasture populations, probably due the fact that many trees are related in the plantation. Correlated mating was significantly higher in pasture (rp=0.47) and plantation (rp=0.51) than in the natural population (rp=0.22), suggesting that trees in natural population are pollinated by a higher number of pollen donors. The paternity correlation was significantly higher within (rp(w)=0.41) than among fruits (rp(a)=0.18), showing a higher probability to find full-sibs within than among fruits. The fixation index was generally lower in seed trees than in their seedlings, suggesting selection for heterozygous individuals from seedling to adult stages. Progeny arrays collected from the natural population had a lower proportion of pairwise full-sibs than in pasture and plantation and higher variance effective size (2.75) than trees in pasture (2.15) and plantations (2.22). Results highlight that seed collections for conservation, breeding and reforestation programs preferentially should be carried out in natural populations due low proportion highest variance effective size within progeny.