RESUMO
Deforestation in the Amazon has resulted in large areas of depleted soils on abandoned pastures and agricultural sites that present a restoration challenge central to protecting biodiversity and ecosystem function in the region. Biochar - charcoal made from waste materials - can improve soil physical, chemical, and biological properties, but the few tropical field trials to date do not give consistent results regarding tree growth. This study presents three years of soil performance and tree growth of a secondary forest shading nontimber forest product (NTFP) plantations of Ocotea quixos (Lauraceae), Myroxylon balsamum (Fabaceae), and their mixture. Open kiln and traditional mound biochars were added at 10 t ha-1 at two sites with contrasting soil types. Biochar additions resulted in pronounced effects on soil properties that varied over time and with depth in the soil profile. Biochar additions generally increased soil organic matter, electrical conductivity, and plant nutrients (in particular K, Ca, and N), but there were interactive effects of NTFP treatments, and stronger responses on the poorer soil type. Biochar amendments resulted in increased tree growth, with a 29 ± 12% increase in aboveground biomass (AGB) on plots amended with kiln biochar and a 23 ± 9% increase in plots with mound biochar compared to controls. Tree species also varied in growth responses to biochar additions, with the largest increases observed in Jaccaranda copaia and Piptocoma discolor. Significant interactions between biochar and NTFP treatments were also seen for tree growth responses, such as Cecropia spp., which only showed increased biomass on mound biochar plots planted with Ocotea quixos. Overall, our results demonstrate a stronger effect of biochar in less favorable soil conditions, and an overriding effect of the legume NTFP in richer soils, and suggest that additions of biochar and legumes are important options to increase productivity and ecological resilience in tropical forest restoration.
Assuntos
Fabaceae , Solo , Solo/química , Ecossistema , Carvão Vegetal/química , Equador , Florestas , Árvores , VerdurasRESUMO
Climate change, habitat loss, and harvesting are potential drivers of species extinction. These factors are unlikely to act on isolation, but their combined effects are poorly understood. We explored these effects in Catopsis compacta, an epiphytic bromeliad commercially harvested in Oaxaca, Mexico. We analyzed local climate change projections, the dynamics of the vegetation patches, the distribution of Catopsis in the patches, together with population genetics and demographic information. A drying and warming climate trend projected by most climate change models may contribute to explain the poor forest regeneration. Catopsis shows a positive mean stochastic population growth. A PVA reveals that quasi-extinction probabilities are not significantly affected by the current levels of harvesting or by a high drop in the frequency of wet years (2%) but increase sharply when harvesting intensity duplicates. Genetic analyses show a high population genetic diversity, and no evidences of population subdivision or a past bottleneck. Colonization mostly takes place on hosts at the edges of the fragments. Over the last 27 years, the vegetation cover has being lost at a 0.028 years(-1) rate, but fragment perimeter has increased 0.076 years(-1). The increases in fragment perimeter and vegetation openness, likely caused by climate change and logging, appear to increase the habitat of Catopsis, enhance gene flow, and maintain a growing and highly genetically diverse population, in spite of harvesting. Our study evidences conflicting requirements between the epiphytes and their hosts and antagonistic effects of climate change and fragmentation with harvesting on a species that can exploit open spaces in the forest. A full understanding of the consequences of potential threatening factors on species persistence or extinction requires the inspection of the interactions of these factors among each other and their effects on both the focus species and the species on which this species depends.
RESUMO
En Colombia se conoce la existencia de cerca de 120 especies de abejas nativas sin aguijón, muchas de las cuales tienen importantes usos y representaciones para diversos grupos sociales y culturales. A pesar de que su cría y manejo (meliponicultura), es una actividad que viene creciendo y tecnificándose en Latinoamérica y otras regiones del mundo, sus características y desarrollo en Colombia han sido poco documentados. Se presentan los resultados de entrevistas y visitas a 75 personas en 16 departamentos de Colombia, que cultivan 25 especies de abejas sin aguijón, agrupadas en 12 géneros. Se encontraron al menos nueve especies más sin identificación completa, se reportan cuatro nuevos registros para el país y se amplía la distribución para 21 taxones. Se presenta información sobre la distribución regional y altitudinal, el cultivo urbano y las denominaciones locales para las abejas. Se revisan algunas características de los géneros cultivados más comunes (Tetragonisca, Melipona, Paratrigona, Scaptotrigona y Nannotrigona) y se discute la importancia del vínculo entre diversidad biológica y cultural que se manifiesta en los nombres locales reportados. Ante un escenario mundial de expansión de la meliponicultura, se resaltan necesidades de investigación y riesgos para la conservación y manejo de la diversidad de abejas sin aguijón y los conocimientos asociados.
There are close to 120 species of native stingless bees in Colombia, many of them with important uses and meanings for diverse social and cultural groups. The stingless beekeeping (meliponiculture) is an activity in process of growth and technification in Latin America and other regions, but there are a little information about their characteristics and development in Colombia. Through information collected by interviews to 75 stingless beekeepers of 16 departments of Colombia, 25 species of stingless bees were identified, grouped in 12 genera. Approximately nine more uncertain species were also found, four new records for the country are presented, and geographical distribution, urban beekeeping and vernacular names reported. The characteristics of most common cultivated genera (Tetragonisca, Melipona, Paratrigona, Scaptotrigona and Nannotrigona) are presented, and the importance of the link between biological and cultural diversity revealed in vernacular names, are discussed. Facing a growing of meliponiculture in the world, some research needs and risks for the conservation and management of the diversity of stingless bees and related knowledge are remarked.
RESUMO
PREMISE OF THE STUDY: Microsatellite loci were isolated and characterized for Brazilian rosewood (Aniba rosaeodora), an endangered neotropical hardwood tree, to investigate population and conservation genetics of this highly valuable nontimber forest resource. ⢠METHODS AND RESULTS: We used an enriched genomic library method to isolate and characterize 11 nuclear microsatellite loci for A. rosaeodora, which exhibited an average of 9.6 and 8.7 alleles per locus in two populations from central Amazonia. Mean observed and expected heterozygosities over the 11 loci were 0.604 and 0.687, and 0.807 and 0.828, respectively, in the two populations. ⢠CONCLUSIONS: The polymorphic microsatellite loci developed for A. rosaeodora showed highly informative content and can be used as a powerful tool in genetic diversity and population structure, gene flow, and mating system studies for conservation purposes.