Identificacion de especies vegetales potencialmente invasoras en la Antártica.
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Date
2025
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Universidad de Concepción
Abstract
El ecosistema terrestre antártico presenta una estructura relativamente simple, dominada por criptógamas y solo dos especies vasculares nativas: Colobanthus quitensis y Deschampsia antarctica. Sin embargo, la creciente presión humana y el cambio climático han aumentado la probabilidad de introducción de diásporas de especies vegetales no nativas con potencial invasor. El presente estudio tuvo como objetivo monitorear la presencia actual de diásporas en la Isla Rey Jorge a través del muestreo de suelo superficial y evaluar la capacidad de establecimiento de especies exóticas bajo condiciones de cambio climático simulado. Se recolectaron muestras en 15 sitios clasificados según su nivel de antropización. Diez sitios altamente intervenidos se ubicaron en Península Fildes; Ardley representó baja presión; Collins y las bases Arctowski, Carlini y Ferraz presentaron presión media a alta. En la identificación de semillas se encontraron cinco de C. quitensis, tres Poáceas (D. antarctica y Poa annua) y dos Juncáceas (Juncus sp.). El análisis palinológico identificó 10 taxones: dos nativas y siete correspondientes a angiospermas y una gimnosperma, coincidiendo con zonas de alta actividad humana, además de esporas. Complementariamente, los ensayos ecofisiológicos demostraron que la disponibilidad hídrica es el factor crítico para el éxito invasor. Especies como Poa annua, Trifolium repens y Juncus bufonius exhibieron una alta plasticidad fisiológica, manteniendo un contenido relativo de agua (CRA > 70%) incluso bajo condiciones de estrés, lo que indica un alto potencial de establecimiento ante futuros escenarios de deshielo. Esta tolerancia permitió a las especies mantener una acumulación de biomasa estable independientemente del tipo de sustrato o densidad de siembra, evidenciando un alto potencial de establecimiento inicial. Estos resultados evidencian el riesgo creciente de introducción de especies alóctonas, reforzando la necesidad de mejorar los protocolos de bioseguridad en la región
The Antarctic terrestrial ecosystem has a relatively simple structure, dominated by cryptogams and only two native vascular species: Colobanthus quitensis and Deschampsia antarctica. However, increasing human pressure and climate change have increased the likelihood of introducing diaspores of non-native plant species with invasive potential. The present study aimed to monitor the current presence of diaspores on King George Island through surface soil sampling and to evaluate the establishment capacity of exotic species under simulated climate change conditions. Samples were collected at 15 sites classified according to their level of anthropization. Ten highly disturbed sites were located on the Fildes Peninsula; Ardley represented low pressure; Collins and the Arctowski, Carlini and Ferraz bases presented medium to high pressure. Seed identification revealed five C. quitensis, three Poaceae (D. antarctica and Poa annua) and two Juncaceae (Juncus sp.). Palynological analysis identified 10 taxa: two native and seven corresponding to angiosperms and one gymnosperm, coinciding with areas of high human activity, in addition to spores. In addition, ecophysiological tests demonstrated that water availability is the critical factor for invasive success. Species such as Poa annua, Trifolium repens, and Juncus bufonius exhibited high physiological plasticity, maintaining a relative water content (RWC > 70%) even under stress conditions, indicating a high potential for establishment in future thaw scenarios. This tolerance allowed the species to maintain stable biomass accumulation regardless of substrate type or sowing density, demonstrating high initial establishment potential. These results highlight the growing risk of introducing alien species, reinforcing the need to improve biosecurity protocols in the region.
The Antarctic terrestrial ecosystem has a relatively simple structure, dominated by cryptogams and only two native vascular species: Colobanthus quitensis and Deschampsia antarctica. However, increasing human pressure and climate change have increased the likelihood of introducing diaspores of non-native plant species with invasive potential. The present study aimed to monitor the current presence of diaspores on King George Island through surface soil sampling and to evaluate the establishment capacity of exotic species under simulated climate change conditions. Samples were collected at 15 sites classified according to their level of anthropization. Ten highly disturbed sites were located on the Fildes Peninsula; Ardley represented low pressure; Collins and the Arctowski, Carlini and Ferraz bases presented medium to high pressure. Seed identification revealed five C. quitensis, three Poaceae (D. antarctica and Poa annua) and two Juncaceae (Juncus sp.). Palynological analysis identified 10 taxa: two native and seven corresponding to angiosperms and one gymnosperm, coinciding with areas of high human activity, in addition to spores. In addition, ecophysiological tests demonstrated that water availability is the critical factor for invasive success. Species such as Poa annua, Trifolium repens, and Juncus bufonius exhibited high physiological plasticity, maintaining a relative water content (RWC > 70%) even under stress conditions, indicating a high potential for establishment in future thaw scenarios. This tolerance allowed the species to maintain stable biomass accumulation regardless of substrate type or sowing density, demonstrating high initial establishment potential. These results highlight the growing risk of introducing alien species, reinforcing the need to improve biosecurity protocols in the region.
Description
Tesis presentada para optar al título de Ingeniero en Biotecnología Vegetal