Bryophyte diversity patterns in flooded and tierra firme forests in the Araracuara Region, Colombian Amazonia

We investigated patterns of bryophyte species richness and composition in two forest types of Colombian Amazonia, non-flooded tierra firme forest and floodplain forest of the Caquetá River. A total of 109 bryophyte species were recorded from 14 0.2 ha plots. Bryophyte life forms and habitats were analyzed, including the canopy and epiphylls. Bryophyte species did not show significant differences between landscapes but mosses and liverworts were different and with opposite responses balancing the overall richness. Independence test showed differences in both life form and habitat use distribution between the two forest types with more fan and mat bryophytes species in the floodplains, and more epiphytic liverworts in the tierra firme forest. Correspondence analysis showed differences in the bryophyte species assemblage between the two forest types where they may be responding to the higher humidity provided by the flooding. Despite of, the environmental differences detected, epiphyll species assemblages were not strongly affected. Apparently, epiphyll habitat is stressful enough to hide the environmental differences between the flooded and Tierra firme forests.Investigamos los patrones de riqueza de especies y composición florística de briofitos en dos tipos de bosque en la Amazonía Colombiana. Bosques no inundados de Tierra firme y bosques periódicamente inundados en los planos inundables del Rió Caquetá. Encontramos 109 especies de briofitos en 14 parcelas de 0.2 ha. Nosotros analizamos diferencias en la distribución de formas de vida y hábitat de los briofitos entre los dos tipos de bosque incluyendo especies del dosel y epifilas. El número de especies de briofitos no mostró diferencias significativas entre los dos tipos de bosque. Pero musgos y hepáticas si tuvieron diferencias con respuestas opuestas balanceando el número total de especies. Pruebas de independencia mostraron diferencias en la distribución de formas de vida y uso de hábitat entre los dos tipos de bosque con más especies de abanicos y esteras en los planos inundables, y más especies de hepáticas epifitas en el bosque de Tierra firme. El análisis de correspondencia mostró diferencias en la composición florística de briofitos entre ambos tipos de bosque, donde las comunidades de briofitos pueden estar respondiendo a un gradiente de humedad aportada por la inundación periódica de los planos inundables. La composición florística de los briofitos epifilos no mostró una separación tan clara entre los tipos de bosque como si fue detectada en los otros hábitat donde los briofitos fueron encontrados. Aparentemente, el hábitat epifilo es suficientemente estresante para ocultar el efecto de las diferentes condiciones ambientales de los bosques inundables y de Tierra firme

The dangers of carbon-centric conservation for biodiversity: a case study in the Andes

Carbon-centric conservation strategies such as the United Nation’s program to Reduce CO2 Emissions from Deforestation and Degradation (REDD+), are expected to simultaneously reduce net global CO2 emissions and mitigate species extinctions in regions with high endemism and diversity, such as the Tropical Andes Biodiversity Hotspot. Using data from the northern Andes, we show, however, that carbon-focused conservation strategies may potentially lead to increased risks of species extinctions if there is displacement (i.e., “leakage”) of land-use changes from forests with large aboveground biomass stocks but relatively poor species richness and low levels of endemism, to forests with lower biomass stocks but higher species richness and endemism, as are found in the Andean highlands (especially low-biomass non-tree growth forms such as herbs and epiphytes that are often overlooked in biological inventories). We conclude that despite the considerable potential benefits of REDD+ and other carbon-centric conservation strategies, there is still a need to develop mechanisms to safeguard against possible negative effects on biodiversity in situations where carbon stocks do not covary positively with species diversity and endemism

¿Por qué implementar estudios de largo plazo en el bosque seco tropical del Caribe colombiano?

Dry forests represent almost half of the world’s tropical forests and they are the most threatened ecosystems by human activities. The growing a knowledge in preservation of the few remaining underlines the significance of establishing monitoring strategies for dry forests which would illustrate their role in the context of the tropical forests’ preservation. In 2001, we began to establish permanent monitoring parcels in the Caribe dry forest. Today, with the support of both, national and international institutions and local actors, a network of 11 widely spread across the region parcels has been established to cover the most important remnants of dry forest from the Caribbean coast, accounting all climatic gradients present. The results obtained by the network include: contents of carbon and forest diversity in relation with climatic variables, carbon fixation rates and population dynamics of important species for the restoration. However, the lack of institutional support at regional and national levels, with some important exceptions, puts at risk the continuity of this important project for the dry forest preservation in context of climatic change adaptation. Nowadays, other institutions have replied to this initiative and have made advances on their own, establishing new monitoring sites in the Caribbean forests. It is of high priority to work for the integration of these efforts in order to create a more ambitious strategy for monitoring the Caribbean forests. For this, interest and compromise from regional institutions and researchers are requiredLos ecosistemas secos ocupan casi la mitad del área total de franja tropical y están entre los más amenazados por las actividades humanas a escala global. El reconocimiento creciente de la importancia de conservar los pocos remanentes que quedan y de iniciar actividades de restauración, resalta la importancia de establecer programas de monitoreo del bosque seco. En 2001 se inició el establecimiento de parcelas permanentes de monitoreo del bosque seco Caribe, con el apoyo de instituciones nacionales e internacionales; a la fecha existen 11 ampliamente distribuidas en algunos de los remanentes de bosque seco más importantesnde la costa Caribe. Los resultados provenientes de la red incluyen el contenido de carbono y la diversidad del bosque en relaciónncon variables climáticas, tasas de fijación de carbono y dinámica de poblaciones de especies importantes para la restauración. No obstante, la falta de apoyo institucional a nivel nacional y regional, con algunas excepciones importantes, pone en peligro la continuidad de este proyecto de alta importancia para la conservación del bosque seco en el contexto de la adaptación al cambio climático. Actualmente, otras instituciones han replicado esta iniciativa y avanzado aisladamente en el establecimiento de nuevos sitios de monitoreo de los bosques del Caribe. Es altamente prioritario trabajar por la integración de estos esfuerzos ya que pueden ser la base para un programa de monitoreo más ambicioso de los bosques del Caribe. Para ello se requiere el interés y el compromiso de instituciones e investigadores de la región Caribe.

Intra- and interannual changes in isoprene emission from central Amazonia

Isoprene emissions are a key component in biosphere-atmosphere interactions, and the most significant global source is the Amazon rainforest. However, intra- and interannual variations in biological and environmental factors that regulate isoprene emission from Amazonia are not well understood and, thereby, are poorly represented in models. Here, with datasets covering several years of measurements at the Amazon Tall Tower Observatory (ATTO) in central Amazonia, Brazil, we (1) quantified canopy profiles of isoprene mixing ratios across seasons of normal and anomalous years and related them to the main drivers of isoprene emission - solar radiation, temperature, and leaf phenology; (2) evaluated the effect of leaf age on the magnitude of the isoprene emission factor (Es) from different tree species and scaled up to canopy with intra- and interannual leaf age distribution derived by a phenocam; and (3) adapted the leaf age algorithm from the Model of Emissions of Gases and Aerosols from Nature (MEGAN) with observed changes in Es across leaf ages. Our results showed that the variability in isoprene mixing ratios was higher between seasons (max during the dry-to-wet transition seasons) than between years, with values from the extreme 2015 El Niño year not significantly higher than in normal years. In addition, model runs considering in situ observations of canopy Es and the modification on the leaf age algorithm with leaf-level observations of Es presented considerable improvements in the simulated isoprene flux. This shows that MEGAN estimates of isoprene emission can be improved when biological processes are mechanistically incorporated into the model.This research was supported by the German Federal Ministry of Education and Research, BMBF funds 01LB1001A; Brazilian Ministry of Science, Technology, Innovation and Communication; FINEP/MCTIC contract 01.11.01248.00); UEA; FAPEAM; LBA/INPA; and SDS/CEUC/RDS-Uatumã. It was also supported by grant nos. NSF-PRFB-1711997 and NSF-1754163. The article processing charges for this open-access publication were covered by the Max Planck Society.Peer reviewe

Isidodendron, un nuevo género neotropical de árboles de la familia Trigoniaceae

Se describe e ilustra un nuevo género de la familia Trigoniaceae, que crece en el bosque húmedo tropical, en la cuenca media del río Magdalena (Colombia). La única especie hasta ahora conocida,presenta hojas alternas, inflorescencias racemosas simples y frutos samaroides. Su posición taxonómica dentro de la familia Trigoniaceae y la implicación fitogeográfica del hallazgo, apenas empieza a ser evaluada.Peer reviewe

¿Por qué implementar estudios de largo plazo en el bosque seco tropical del Caribe Colombiano?

Dry forests represent almost half of the world’s tropical forests and they are the most threatened ecosystems by human activities. The growing a knowledge in preservation of the few remaining underlines the significance of establishing monitoring strategies for dry forests which would illustrate their role in the context of the tropical forests’ preservation. In 2001, we began to establish permanent monitoring parcels in the Caribe dry forest. Today, with the support of both, national and international institutions and local actors, a network of 11 widely spread across the region parcels has been established to cover the most important remnants of dry forest from the Caribbean coast, accounting all climatic gradients present. The results obtained by the network include: contents of carbon and forest diversity in relation with climatic variables, carbon fixation rates and population dynamics of important species for the restoration. However, the lack of institutional support at regional and national levels, with some important exceptions, puts at risk the continuity of this important project for the dry forest preservation in context of climatic change adaptation. Nowadays, other institutions have replied to this initiative and have made advances on their own, establishing new monitoring sites in the Caribbean forests. It is of high priority to work for the integration of these efforts in order to create a more ambitious strategy for monitoring the Caribbean forests. For this, interest and compromise from regional institutions and researchers are required.Los ecosistemas secos ocupan casi la mitad del área total de franja tropical y están entre los más amenazados por las actividades humanas a escala global. El reconocimiento creciente de la importancia de conservar los pocos remanentes que quedan y de iniciar actividades de restauración, resalta la importancia de establecer programas de monitoreo del bosque seco. En 2001 se inició el establecimiento de parcelas permanentes de monitoreo del bosque seco Caribe, con el apoyo de instituciones nacionales e internacionales; a la fecha existen 11 ampliamente distribuidas en algunos de los remanentes de bosque seco más importantesnde la costa Caribe. Los resultados provenientes de la red incluyen el contenido de carbono y la diversidad del bosque en relaciónncon variables climáticas, tasas de fijación de carbono y dinámica de poblaciones de especies importantes para la restauración. No obstante, la falta de apoyo institucional a nivel nacional y regional, con algunas excepciones importantes, pone en peligro la continuidad de este proyecto de alta importancia para la conservación del bosque seco en el contexto de la adaptación al cambio climático. Actualmente, otras instituciones han replicado esta iniciativa y avanzado aisladamente en el establecimiento de nuevos sitios de monitoreo de los bosques del Caribe. Es altamente prioritario trabajar por la integración de estos esfuerzos ya que pueden ser la base para un programa de monitoreo más ambicioso de los bosques del Caribe. Para ello se requiere el interés y el compromiso de instituciones e investigadores de la región Caribe

Disentangling the environmental heterogeneity, floristic distinctiveness and current threats of tropical dry forests in Colombia

Tropical dry forests (TDFs) have been defined as a single biome occurring mostly in the lowlands where there is a marked period of drought during the year. In the Neotropics, dry forests occur across contrasting biogeographical regions that contain high beta diversity and endemism, but also strong anthropogenic pressures that threaten their biodiversity and ecological integrity. In Colombia, TDFs occur across six regions with contrasting soils, climate, and anthropogenic pressures, therefore being ideal for studying how these variables relate to dry forest species composition, successional stage and conservation status. Here, we explore the variation in climate and soil conditions, floristic composition, forest fragment size and shape, successional stage and anthropogenic pressures in 571 dry forest fragments across Colombia. We found that TDFs should not be classified solely on rainfall seasonality, as high variation in precipitation and temperature were correlated with soil characteristics. In fact, based on environmental factors and floristic composition, the dry forests of Colombia are clustered in three distinctive groups, with high species turnover across and within regions, as reported for other TDF regions of the Neotropics. Widely distributed TDF species were found to be generalists favored by forest disturbance and the early successional stages of dry forests. On the other hand, TDF fragments were not only small in size, but highly irregular in shape in all regions, and comprising mostly early and intermediate successional stages, with very little mature forest left at the national level. At all sites, we detected at least seven anthropogenic disturbances with agriculture, cattle ranching and human infrastructure being the most pressing disturbances throughout the country. Thus, although environmental factors and floristic composition of dry forests vary across regions at the national level, dry forests are equally threatened by deforestation, degradation and anthropogenic pressures all over the country, making TDFs a top priority for conservation in Colombia. © 2018 The Author(s). Published by IOP Publishing Ltd