Dinámica y estructura en ecosistemas forestales y su aporte al ciclo del carbono en la Península de Osa, Costa Rica

[ES] La siguiente investigación se enfocará a caracterizar la dinámica de ecosistemas de formaciones forestales en función de la diversidad florística, estructura forestal, los cambios espacio-temporales y el rol del carbono contenido en la biomasa, necromasa y suelos, en los sitios de Agua Buena de Rincón y Piro, en la Península de Osa, Costa Rica. De esta manera se busca comprender el aporte que hacen estos bosques en cuanto a la diversidad de árboles, palmas y bejucos con un diámetro ≥ 10 cm de Dap, así como determinar las diferencias espacio-temporales en los componentes vegetacionales, la dinámica del crecimiento, los procesos ecológicos por mortalidad y reclutamiento, la cuantificación del carbono contenido en la biomasa aérea y subterránea y suelo que caracterizan las formaciones forestales en la Península de Osa, Costa Rica. Dentro de los alcances de la investigación en función de sus metas se buscará: a. Describir y comparar los componentes vegetacionales para aquellas especies de árboles, palmas y bejucos con un diámetro ≥ 10 cm de Dap, en función de su estructura, composición florística, riqueza de especies y diversidad con el fin de comprender la influencia de los factores a nivel de sitio sobre la presencia de las especies. b. Comprender la dinámica de las especies presentes mediante la cuantificación y comparación de los patrones de crecimiento en función de su estructura y la relación de estos con el sitio y el tipo de bosque. c. Estimar y comparar la productividad en función de la cuantificación del carbono contenido en la biomasa, necromasa y suelo y su distribución en las formaciones forestales, con el fin de comprender la dinámica del carbono a nivel de ecosistema. d. Comprender la dinámica de la biodiversidad de los bosques primarios y secundarios evaluados, como un medio para entender el rol e importancia de los bosques en la Península de Osa como estrategia de conservación

Does the persistence of sweet chestnut depend on cultural inputs? Regeneration, recruitment, and mortality in Quercus- and Castanea-dominated forests

[EN]Quercus secondary forests show a gradual transition toward mixed forests, with sweet chestnut (Castanea sativa) becoming increasingly abundant in the western Spanish Central System.It shows a certain resistance to competitive displacement by Quercus pyrenaica.Sweet chestnut, Castanea sativa, is a component of European broadleaf forests and is one of the most managed trees.Our work aimed to identity the main factors that limit the establishment of C. sativa and to analyze the recruitment and mortality processes of C. sativa trees. The age, growth ring patterns, regeneration density, and the spatial structure of trees and saplings in 11 plots in the Spanish Central System were analyzed.s Chestnut seedling density increased with C. sativa basal area, but transition toward the sapling stage appeared limited owing to light availability. In Quercus pyrenaica secondary forests, sparse canopies did not constrain chestnut regeneration, and in old chestnut stands, C. sativa showed a certain resistance to competitive displacement. By contrast, mixed young coppices showed a high mortality, most likely due to competition with other vigorous resprouter

Climatic and edaphic controls over tropical forest diversity and vegetation carbon storage

Tropical rainforests harbor exceptionally high biodiversity and store large amounts of carbon in vegetation biomass. However, regional variation in plant species richness and vegetation carbon stock can be substantial, and may be related to the heterogeneity of topoedaphic properties. Therefore, aboveground vegetation carbon storage typically differs between geographic forest regions in association with the locally dominant plant functional group. A better understanding of the underlying factors controlling tropical forest diversity and vegetation carbon storage could be critical for predicting tropical carbon sink strength in response to projected climate change. Based on regionally replicated 1-ha forest inventory plots established in a region of high geomorphological heterogeneity we investigated how climatic and edaphic factors affect tropical forest diversity and vegetation carbon storage. Plant species richness (of all living stems >10 cm in diameter) ranged from 69 to 127 ha-1 and vegetation carbon storage ranged from 114 to 200 t ha-1. While plant species richness was controlled by climate and soil water availability, vegetation carbon storage was strongly related to wood density and soil phosphorus availability. Results suggest that local heterogeneity in resource availability and plant functional composition should be considered to improve projections of tropical forest ecosystem functioning under future scenarios

Dinámica y estructura en ecosistemas forestales y su aporte al ciclo de carbono en la Península de Osa, Costa Rica

Tesis doctoral para aspirar al Grado de Doctor Biología y Conservación de la Biodiversidad.Caracteriza la dinámica de ecosistemas de formaciones forestales en función de la diversidad florística, estructura forestal, los cambios espacio-temporales y el rol del carbono contenido en la biomasa, necromasa y suelos, en los sitios de Agua Buena de Rincón y Piro, en la Península de Osa, Costa Rica. De esta manera se busca comprender el aporte que hacen estos bosques en cuanto a la diversidad de árboles, palmas y bejucos con un diámetro ≥ 10 cm de Dap, así como determinar las diferencias espacio-temporales en los componentes vegetacionales, la dinámica del crecimiento, los procesos ecológicos por mortalidad y reclutamiento, la cuantificación del carbono contenido en la biomasa aérea y subterránea y suelo que caracterizan las formaciones forestales en la Península de Osa, Costa Rica

Diversität und Zusammensetzung tropischer Pflanzengesellschaften in der Golfo Dulce Region

The Golfo Dulce region located in southwestern Costa Rica represents one of the remnant global biodiversity hotspots containing the largest Pacific lowland tropical forest in Central America. Recent biogeographical analyses revealed a close relation of taxonomic tree species composition to northern South America. However, the underlying factors leading to the extraordinary taxonomic richness of the region have so far remained elusive. In this study, we analyzed the composition of tropical forest plant communities (trees, lianas and palms with a diameter at breast height ≥10 cm) occurring in one-hectare permanent forest inventory plots. To that end, we established 20 forest sites across the Golfo Dulce region, i.e. 5 geographic locations each comprising 4 forest habitat types in ridge, slope and ravine positions, as well as in secondary forest stands. Our study highlights the oligarchic dominance of tropical forest plant communities in the Golfo Dulce region, and further suggests that plant species composition is associated with topography, disturbance history and edaphic properties. The finding that oligarchic and rare species are affected by environmental filtering has important implications for assessment and modeling of important ecosystem functions, such as carbon storage and productivity, as well as nutrient cycling and trophic interactions and thus could potentially improve biodiversity conservation and management strategies.Die Golfo Dulce-Region im Südwesten von Costa Rica ist einer der letzten globalen Biodiversitäts-Hotspots mit dem größten verbliebenen tropischen Wald im pazifischen Tiefland in Mittelamerika. Jüngste biogeografische Analysen der taxonomischen Baumartenzusammensetzung zeigten eine enge Beziehung zu den Pflanzengesellschaften Südamerikas. Die zugrundeliegenden Faktoren, die zu dem außerordentlichen taxonomischen Reichtum der Region führten, sind jedoch bislang schwer fassbar. In dieser Studie haben wir die Zusammensetzung der tropischen Vegetation (Bäume, Lianen und Palmen mit einem Durchmesser in Brusthöhe ≥ 10 cm) auf 20 Inventarflächen von jeweils 1ha Größe (5 geografische Standorte mit jeweils 4 Habitatstypen in Kamm-, Hang- und Schlucht- Position, sowie einem Sekundärwald) analysiert. Unsere Studie beschreibt die Dominanz häufiger tropischer Pflanzenarten und legt nahe, dass die Zusammensetzung der Vegetation mit der Topographie, der Störungsgeschichte und den edaphischen Eigenschaften zusammenhängt. Die Feststellung, dass die Zusammensetzung von sowohl häufig vorkommenden als auch eher seltenen, Großteils endemischen Arten von denselben Umweltfaktoren beeinflusst wird, birgt interessante Erkenntnisse über wichtige Ökosystemfunktionen wie die Kohlenstoffspeicherung und die Produktivität des Ökosystems und könnte somit helfen Strategien zur Erhaltung und Bewirtschaftung der Artenvielfalt in tropischen Ökosystemen zu entwickeln.UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biologí

Data from: Beta diversity and oligarchic dominance in the tropical Forests of Southern Costa Rica

Recent studies have reported a consistent pattern of strong dominance of a small subset of tree species in Neotropical forests. These species have been called ‘hyperdominant’ at large geographical scales and ‘oligarchs’ at regional-landscape scales when being abundant and frequent. Forest community assembly is shaped by environmental factors and stochastic processes, but so far the contribution of oligarchic species to the variation of community composition (i.e. beta diversity) remains poorly known. To that end, we established 20 1-ha plots, i.e. 5 sites with 4 forest types (ridge, slope and ravine primary forest, and secondary forest) per site, in humid lowland tropical forests of southwestern Costa Rica to (1) investigate how community composition responds to differences in topography, successional stage and distance among plots for different groups of species (all, oligarch, common and rare/very rare species) and (2) identify oligarch species characterizing changes in community composition among forest types. From a total of 485 species of trees, lianas and palms recorded in this study only 27 species (i.e. 6%) were nominated as oligarch species. Oligarch species accounted for 37% of all recorded individuals and were present in at least half of the plots. Plant community composition significantly differed among forest types, thus contributing to beta diversity at the landscape-scale. Oligarch species was the component best explained by geographical and topographic variables, allowing a confident characterization of the beta diversity among tropical lowland forest stands

tree_abundance_data_GolfoDulce_BITR-18-091R2

Abundance (individuals per hectare) of tree and palm species in the Golfo Dulce region, Costa Ric

README

Description of the tree abundance data file (.xlsx