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Patterns of composition, richness and phylogenetic diversity of woody plant communities of Quillaja saponaria Molina (Quillajaceae) in the Chilean sclerophyllous forest
No full textABSTRACT Sclerophyllous forest is among the most representative types of woody plant communities in central Chile where Quillaja saponaria is considered to be one of the most important species. In this study, we analysed the main factors that explain the geographical patterns of variation in composition, richness and phylogenetic diversity of woody plant communities in the Chilean sclerophyllous forest where Quillaja saponaria is present. Vegetation surveys were performed for trees and shrubs in thirty-nine sites from 30° to 38° of latitude South in the Mediterranean biome of Chile. Composition, richness, alfa diversity and phylogenetic diversity metrics of the communities were calculated and associated with spatial (latitude, longitude and altitude), climate (annual mean temperature, annual precipitation, aridity), and disturbance variables (type of adjacent vegetation matrix) using multiple regression models. Sixty taxa were identified, distributed in 29 families, including 23 trees and 37 shrubs. A significant effect of the type of adjacent vegetation matrix (i.e. agricultural land, commercial forestry plantation or natural forest) on diversity and composition of the sampled communities was found. Significant effects of latitude on diversity, and altitude, latitude and annual mean temperature on composition were also found. Metrics of phylogenetic diversity and structure were only associated with altitude and latitude. In conclusion, diversity, composition and phylogenetic structure patterns of sclerophyllous forest communities are associated with spatial and climate variables, and anthropogenic disturbance has also caused important changes in these communities
Frugivory of Persea lingue (Lauraceae) and its effect on seed germination in southern Chile
No full textFrugivory is a common interaction mechanism between plants and animals in the temperate rainforest of southern South America. In this study, we examined primary dispersal and predation stages of Persea lingue (Ruiz et Pav.) Nees (Lauraceae), an endemic large-seeded tree of these forests. The main goal was to determine the identity of vertebrate seed dispersers of P. lingue, to distinguish legitimate seed dispersers, pulp consumers and seed predators, and their influence on seed germination. In order to know which birds and small mammals were feeding P. lingue seeds, we observed 20 P. lingue canopies, and live traps baited with P. lingue seeds were installed in fragment forests in south-central Chile. To determine whether birds could be legitimate dispersers of P. lingue, we collected regurgitated and fecal samples. We examined whether rodents removed the fruit pulp, the seeds, or the whole fruit. Additionally, we studied if seeds placed on the forest floor were removed by rodents. In a final experiment we conducted germination trials to establish whether pulp removal (by birds, rodents, or artificially-removed) influenced germination rates. We found six bird species feeding on P. lingue seeds. None of them defecated intact seeds, but, Turdus falcklandii Quoy & Gaimard (Turdinae) and Xolmis pyrope (Kittlitz) (Tyrannidae) regurgitated intact seeds. We captured five species of rodents in Sherman traps. Four of them left intact seeds. We did not find any effect of the seed handling types (pulp consumption vs. seed regurgitation) in seed germination rates. However, pulp removal was an important factor for germination success. We conclude that T. falcklandii and X. pyrope are legitimate seed dispersers of P. lingue, since they swallow the whole fruit and regurgitate the intact seed. Abrothrix olivaceus (Waterhouse) (Cricetidae) and probably Oligoryzomys longicaudatus (Bennett) (Cricetidae) are potential secondary dispersers of P. lingue seeds, as they prefer to eat the fruit pulp rather than the seeds
Water transport and gas exchange in the non-vascular plant Dendroligotrichum dendroides (Brid. ex Hedw.)Broth. (Polytrichaceae, Bryophyta)
No full textSe midió la conductancia hidráulica específica (Ks) y el intercambio de gases en individuos de D. dendroides (Polytrichaceae, Musci). Ks fue más alta que en algunas coníferas y comparable con algunas angiospermas leñosas, pero la fotosíntesis (Amax) fue relativamente baja. Los resultados muestran que una planta no vascular puede alcanzar altos valores de Ks, sugiriendo un funcionamiento "vascular" similar a las traqueófitas
Water crisis in Petorca basin, Chile: The combined effects of a mega-drought and water management
No full textSince 2010, Chile has experienced one of the most severe droughts over the last century, the so-called mega-drought (MD). The MD conditions, combined with intensive agricultural activities and the current water management system, have led to water scarcity problems in Mediterranean and Semi-arid regions of Chile. An emblematic case is the Petorca basin, where a water crisis is undergone. To characterize this crisis, we analyzed water provision by using tree-ring records, remote sensing, instrumental data, and allocated water rights within the basin. Results indicate that the MD is the most severe dry period over the last 700-years of streamflow reconstruction. During the MD, streamflow and water bodies of the upper parts of the basin have been less affected than mid and low areas of this valley, where consumptive withdrawals reach up to 18% of the mean annual precipitation. This extracted volume is similar to the MD mean annual precipitation deficits. The impacts of the current drought, along with the drier climate projections for Central Chile, emphasize the urgency for faster policy changes related to water provision. Climate change adaptation plans and policies should enhance the current monitoring network and the public control of water use to secure the water access for inhabitants and productive activities
RISK ASSESSMENT OF AGRICULTURAL INTENSIFICATION ON N DEPOSITION ON PRISTINE FORESTS AND PLANTATIONS IN SOUTHERN CHILE
No full textTECOPHILAEA CYANOCROCUS LEYB. (TECOPHILAECEAE) REDESCUBIERTA EN SU HABITAT NATURAL
No full textTecophilaea cyanocrocus Leyb., es una geófita altoandina endémica de la región Metropolitana de Chile. Fue descrita en 1862. Debido al potencial ornamental de sus flores azules, sus cormos fueron extraídos en grandes cantidades y exportados a Europa. Actualmente es cultivada en muchos países. A partir de la mitad del siglo XX se la considera extinguida en la naturaleza. Se da a conocer el descubrimiento de una población de la especie en las montañas de la Región Metropolitana, en la primavera de 200
EFFECT OF DENSITY AND FLOWER SIZE ON THE REPRODUCTIVE SUCCESS OF NOTHOSCORDUM GRAMINUM (ALLIACEAE)
No full textThe size, form and color are signals used by flowers to attract their pollinators. Large and showy color flowers usually receive higher pollinators visitation rates. According to the optimal forage theory, pollinators would tend to visit flower patches where they obtain the maximum reward regarding the energy expenditure in flower search. In high density patches, flowers are very close each other, hence, flower discrimination by pollinators would tend to be low. In low density patches, however, where the forage effort is greater, larger flowers are usually associated with higher rewards and would receive higher pollinators visitation achieving greater fitness than co-especifics with smaller flowers. In the present study we assessed the effects of flower density and size on the reproductive success (RS) of Nothoscordum gramineum. Four patches of different densities were delimited and the flowers size of the half of individuals at each patch was manually reduced. Results showed that RS was significantly greater in individuals with larger flowers. Additionally, density has a positive effect on RS, especially in large size flowers. Nevertheless, fruition success reached maximum values in patches of intermediate density. Individuals with cut flowers did not varied the RS with the variation of the density, suggesting that flower size is the most important attribute measured as advertisement by pollinators in N. gramineum. Our results do not support the hypothesis that in high density patches, flower displays have low importanc
Importancia de la vegetación ribereña de Nothofagus dombeyi (Mirb.) Oerst. en el régimen térmico de sistemas fluviales andinos del sur de Chile
No full textA nivel global la temperatura de los ríos sigue siendo tema de investigación en ecología fluvial, pero el conocimiento de su variabilidad espacio-temporal en diversos sistemas fluviales aún es limitada y en algunos casos desconocida. Este estudio tuvo por objetivo comparar el régimen térmico natural de dos ecosistemas fluviales andinos con diferente vegetación ribereña (estepa y bosque de Nothofagus dombeyi). La temperatura en ambos sitios fue registrada con una resolución de 15 min desde enero a julio de 2011. La temperatura media, máxima y rango diario del agua mostraron diferencias significativas, con valores más bajos en el río con presencia de N. dombeyi. En relación al ciclo diario, se observó un leve retraso en la temperatura mínima y adelanto en la máxima para el río con bosque nativo. La realización de monitoreos continuos mediante sensores de temperatura permitió determinar contrastes en el régimen térmico y sugiere que la sombra generada por el dosel reduce la radiación solar que recibe el río y la temperatura máxima (± 4 °C) en ríos andinos. Asimismo, la conservación de la cobertura boscosa de N. dombeyi en la zona andina podría ser importante para moderar y mitigar la ocurrencia de temperaturas más altas a consecuencia de los escenarios de calentamiento global proyectados para la zona
Maqui: el fruto silvestre de mayor importancia en Chile
No full text248 páginasCon el objetivo de contribuir al conocimiento de las formaciones de maqui, así como al rescate cultural de la recolección y a la generación de nuevas oportunidades de negocios, el Instituto Forestal a través de su Línea de Investigación de PFNM, entrega estos antecedentes para orientar a quienes quieran explorar y emprender en forma sustentable, en este interesante ámbito de las ciencias forestales