Vulnerability in the offer of ecosystem services (SE) and the conservation of biodiversity in Antioquia

RESUMEN: La constante demanda de área para la producción y uso de Servicios Ecosistémicos, como consecuencia de la creciente población y consumo de recursos, conlleva a la pérdida de bosques y el declive de la biodiversidad. Con el objetivo de determinar el posible futuro de los bosques y la biodiversidad en el departamento de Antioquia (Colombia). En este artículo analizamos variables que generan presiones a los ecosistemas y su relación con las estrategias de conservación a través de áreas protegidas. Para conocer la conexión entre el mantenimiento de la oferta de Servicios Ecosistémicos, los incrementos entre los sectores productivos y algunas medidas de disminución de los servicios, dividimos las variables en tres grupos: i.) Variables para cuantificar la oferta de servicios de los ecosistemas; ii.) Variables de desarrollo económico; iii.) Variables de medición de la pérdida de funciones ecosistémicas. Mediante el uso de mapas de las subregiones de Antioquia, se pudieron conocer los porcentajes de ocupación de Servicios Ecosistémicos, entre ellos, la provisión de maderas y alimentos, la regulación (mitigación de emisiones de CO2, seguridad hídrica y fertilidad del suelo) y los servicios culturales (representatividad natural). Encontramos, a partir de todas las variables de consumo de Servicios Ecosistémicos consideradas, que ninguna variable presenta mayor peso respecto a las demás y que parece existir una relación entre pérdidas y ganancias de bosques con los niveles de las estrategias de conservación: en las subregiones donde las medidas de preservación son estrictas se presentan ganancias de bosque; y, por el contrario, en las subregiones donde predominan estrategias de desarrollo sostenible, como los Distritos de Manejo Integrado –DMI–, son constantes y mayores las tasas de deforestación. Los resultados obtenidos indican que los ecosistemas estratégicos son muy vulnerables al desarrollo económico y que las políticas de planeación del territorio fundamentadas en áreas protegidas con carácter de conservación estricta son una estrategia apropiada para disminuir las pérdidas de diversidad y el consecuente desabastecimiento de Servicios Ecosistémicos esenciales para la humanidad, como lo son la seguridad hídrica, el clima sostenible y el equilibrio global.ABSTRACT: The constant demand of area for the production and use of Ecosystem Services, as a consequence of the growing population and consumption of resources, determines the losses of forests and the decline of biodiversity. In order to determine the possible future of forests and biodiversity in the department of Antioquia (Colombia), in this article we analyze variables that generate pressures on ecosystems and their relationship with conservation strategies through protected areas. To know the link between maintaining the supply of ecosystemic services, productive clusters increase, and some actions to reduce such services, we divide the variables into three groups: i.) Variables to quantify the supply of ecosystemic services; ii.) Economic development variables; iii.) Variables for measuring the loss of ecosystemic functions. Through the use of maps of the subregions of Antioquia, it was possible to know the occupancy rates of ecosystemic services as follows: deforestation and the loss of food provision services, regulation (mitigation of CO2 emissions, water supply provision and fertility of soil) as well as cultural (natural representativeness). We found, from all the variables of consumption of ecosystemic services considered, that no variable has a greater weight in relation to the others and that there seems to be a relationship between losses and gains of forests driven by the levels of the conservation strategies, since, in the subregions where the preservation measures are strict, forest gains are present; and, on the contrary, in subregions where sustainable development strategies predominate, such as the Integrated Management Districts –DMI–, deforestation rates are constant and higher. The results obtained indicate that the strategic ecosystems of the planet are very vulnerable to economic development and that territorial planning policies based on protected areas with a strict conservation nature are an appropriate strategy to reduce diversity losses and the consequent shortage of ecosystemic services, essential for humanity such as water supply provision, sustainable climate and global equilibrium

Variable thermal plasticity of leaf functional traits in Andean tropical montane forests

Tropical montane forests (TMFs) are biodiversity hotspots and provide vital ecosystem services, but they are disproportionately vulnerable to climate warming. In the Andes, cold-affiliated species from high elevations are being displaced at the hot end of their thermal distributions by warm-affiliated species migrating upwards from lower elevations, leading to compositional shifts. Leaf functional traits are strong indicators of plant performance and at the community level have been shown to vary along elevation gradients, reflecting plant adaptations to different environmental niches. However, the plastic response of such traits to relatively rapid temperature change in Andean TMF species remains unknown. We used three common garden plantations within a thermosequence in the Colombian Andes to investigate the warming and cooling responses of key leaf functional traits in eight cold- and warm-affiliated species with variable thermal niches. Cold-affiliated species shifted their foliar nutrient concentrations when exposed to warming, while all other traits did not significantly change; contrastingly, warm-affiliated species were able to adjust structural, nutrient and water-use efficiency traits from acquisitive to conservative strategies in response to cooling. Our findings suggest that cold-affiliated species will struggle to acclimate functional traits to warming, conferring warm-affiliated species a competitive advantage under climate change

¿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.

PATRONES DE FRECUENCIA Y ABUNDANCIA DE SISTEMAS DE DISPERSIÓN DE PLANTAS EN BOSQUES COLOMBIANOS Y SU RELACIÓN CON LAS REGIONES GEOGRÁFICAS DEL PAÍS

The study of plant dispersal systems allows to go in depth in aspects that define the regeneration of forests, being essential to understand not only the population dynamics of plants but also the ecological relationships that emerge within ecosystems. In Colombia there is not a broad scale study showing the patterns of frequency and abundance of dispersal systems in different geographical regions (Amazonian, Andean, Caribbean, Upper Magdalena, Middle Magdalena, Orinoco, Pacific). Based on information of the identity and abundance of plants found in 101 vegetation plots of 1-ha, we explored the differences and associations in the frequency and abundance of dispersal systems between geographic regions. Additionally, we explored the importance value of families and genera per dispersal system, and the association between genera and geographic regions. The results show that environmental factors would be more important than the biogeographic history of the region in determining patterns of dispersal systems, reinforcing the importance of seed dispersal mediated by animals in tropical forests of different biogeographic regions.El estudio de los sistemas de dispersión de las plantas permite entender la regeneración de los bosques, la dinámica poblacional de las plantas y las relaciones ecológicas que emergen dentro de los ecosistemas. En el presente estudio analizamos los patrones de sistemas de dispersión de semillas para Colombia, en relación con las regiones geográficas Amazónica, Andina, Caribe, Magdalena Alto, Magdalena Medio, Orinoquía y Pacífica. A partir de la información sobre la identidad y abundancia de plantas encontradas en 101 parcelas de vegetación de 1-ha, se exploraron los cambios en la frecuencia relativa y abundancia relativa de sistemas de dispersión entre las regiones geográficas. Adicionalmente, se determinaron las afinidades florísticas entre las regiones, así como la representatividad de las familias y géneros por sistema de dispersión. La endozoocoria fue altamente representativa en diferentes niveles taxonómicos (especie, género y familia), y su representatividad cambió entre las distintas regiones geográficas. Estos cambios podrían explicarse a partir de diferencias ecológicas entre las regiones

Hyperdominance in Amazonian Forest Carbon Cycling

While Amazonian forests are extraordinarily diverse, the abundance of trees is skewed strongly towards relatively few ‘hyperdominant’ species. In addition to their diversity, Amazonian trees are a key component of the global carbon cycle, assimilating and storing more carbon than any other ecosystem on Earth. Here we ask, using a unique data set of 530 forest plots, if the functions of storing and producing woody carbon are concentrated in a small number of tree species, whether the most abundant species also dominate carbon cycling, and whether dominant species are characterized by specific functional traits. We find that dominance of forest function is even more concentrated in a few species than is dominance of tree abundance, with only ≈1% of Amazon tree species responsible for 50% of carbon storage and productivity. Although those species that contribute most to biomass and productivity are often abundant, species maximum size is also influential, while the identity and ranking of dominant species varies by function and by region

The pace of life for forest trees.

Tree growth and longevity trade-offs fundamentally shape the terrestrial carbon balance. Yet, we lack a unified understanding of how such trade-offs vary across the world's forests. By mapping life history traits for a wide range of species across the Americas, we reveal considerable variation in life expectancies from 10 centimeters in diameter (ranging from 1.3 to 3195 years) and show that the pace of life for trees can be accurately classified into four demographic functional types. We found emergent patterns in the strength of trade-offs between growth and longevity across a temperature gradient. Furthermore, we show that the diversity of life history traits varies predictably across forest biomes, giving rise to a positive relationship between trait diversity and productivity. Our pan-latitudinal assessment provides new insights into the demographic mechanisms that govern the carbon turnover rate across forest biomes

The number of tree species on Earth

One of the most fundamental questions in ecology is how many species inhabit the Earth. However, due to massive logistical and financial challenges and taxonomic difficulties connected to the species concept definition, the global numbers of species, including those of important and well-studied life forms such as trees, still remain largely unknown. Here, based on global groundsourced data, we estimate the total tree species richness at global, continental, and biome levels. Our results indicate that there are 73,000 tree species globally, among which ∼9,000 tree species are yet to be discovered. Roughly 40% of undiscovered tree species are in South America. Moreover, almost one-third of all tree species to be discovered may be rare, with very low populations and limited spatial distribution (likely in remote tropical lowlands and mountains). These findings highlight the vulnerability of global forest biodiversity to anthropogenic changes in land use and climate, which disproportionately threaten rare species and thus, global tree richness

The number of tree species on Earth.

One of the most fundamental questions in ecology is how many species inhabit the Earth. However, due to massive logistical and financial challenges and taxonomic difficulties connected to the species concept definition, the global numbers of species, including those of important and well-studied life forms such as trees, still remain largely unknown. Here, based on global ground-sourced data, we estimate the total tree species richness at global, continental, and biome levels. Our results indicate that there are ∼73,000 tree species globally, among which ∼9,000 tree species are yet to be discovered. Roughly 40% of undiscovered tree species are in South America. Moreover, almost one-third of all tree species to be discovered may be rare, with very low populations and limited spatial distribution (likely in remote tropical lowlands and mountains). These findings highlight the vulnerability of global forest biodiversity to anthropogenic changes in land use and climate, which disproportionately threaten rare species and thus, global tree richness

The number of tree species on Earth.

One of the most fundamental questions in ecology is how many species inhabit the Earth. However, due to massive logistical and financial challenges and taxonomic difficulties connected to the species concept definition, the global numbers of species, including those of important and well-studied life forms such as trees, still remain largely unknown. Here, based on global ground-sourced data, we estimate the total tree species richness at global, continental, and biome levels. Our results indicate that there are ∼73,000 tree species globally, among which ∼9,000 tree species are yet to be discovered. Roughly 40% of undiscovered tree species are in South America. Moreover, almost one-third of all tree species to be discovered may be rare, with very low populations and limited spatial distribution (likely in remote tropical lowlands and mountains). These findings highlight the vulnerability of global forest biodiversity to anthropogenic changes in land use and climate, which disproportionately threaten rare species and thus, global tree richness

Evenness mediates the global relationship between forest productivity and richness

1. Biodiversity is an important component of natural ecosystems, with higher species richness often correlating with an increase in ecosystem productivity. Yet, this relationship varies substantially across environments, typically becoming less pronounced at high levels of species richness. However, species richness alone cannot reflect all important properties of a community, including community evenness, which may mediate the relationship between biodiversity and productivity. If the evenness of a community correlates negatively with richness across forests globally, then a greater number of species may not always increase overall diversity and productivity of the system. Theoretical work and local empirical studies have shown that the effect of evenness on ecosystem functioning may be especially strong at high richness levels, yet the consistency of this remains untested at a global scale. 2. Here, we used a dataset of forests from across the globe, which includes composition, biomass accumulation and net primary productivity, to explore whether productivity correlates with community evenness and richness in a way that evenness appears to buffer the effect of richness. Specifically, we evaluated whether low levels of evenness in speciose communities correlate with the attenuation of the richness–productivity relationship. 3. We found that tree species richness and evenness are negatively correlated across forests globally, with highly speciose forests typically comprising a few dominant and many rare species. Furthermore, we found that the correlation between diversity and productivity changes with evenness: at low richness, uneven communities are more productive, while at high richness, even communities are more productive. 4. Synthesis. Collectively, these results demonstrate that evenness is an integral component of the relationship between biodiversity and productivity, and that the attenuating effect of richness on forest productivity might be partly explained by low evenness in speciose communities. Productivity generally increases with species richness, until reduced evenness limits the overall increases in community diversity. Our research suggests that evenness is a fundamental component of biodiversity–ecosystem function relationships, and is of critical importance for guiding conservation and sustainable ecosystem management decisions