Тип публикации: доклад, тезисы доклада, статья из сборника материалов конференций
Конференция: Enviromis 2016; Томск; Томск
Год издания: 2016
Аннотация: Treeline ecotone in the Tropical Andes is characterized by a complex transition boundary between high mountain forest and grassland páramos vegetation, very sensitive to climate conditions. Current global warming trends may lead to an upslope shift of plant species in the treeline and modify its altitudinal position. In this work, Показать полностьюwe employed and adaptation of Herdberg´s (1964) life-form classification systemfor tropical alpine environments, to analyse the effect of altitude and slope orientation on plant life-form distribution and asses the dynamics and structure of the tropical treeline under climate change scenarios (focussed in temperature changes for the years 2040 and 2060). The study was carried out along and altitudinal gradient of 250 m (between 3300 to 3550 m of altitude) from the upper forest-line in the Venezuelan Andes. We found clear distributional patterns for each life- form in terms of altitude and slope orientation; trees decreased in abundance with altitude and distance to the continuous forest, being replaced by tussock grasses, small sclerophyllous shrubs and caulescent rosettes with elevation. Interestingly, pubescent and non-pubescent caulescent rosettes showed a contrasting distribution in terms of elevation and aspect, indicating that attributes affecting leaf thermal balance can influence plant spatial distribution patterns across the ecotone. Projection models under future climate scenario reflected differential responses on the rate of change for each plant life-form. Models suggest an upslope shift of woody species over tussockgrasses and caulescent rosettes, increasing their density and altitudinal range; this could be associated with a change in grassland páramo structure where woody species begin to dominate in warming scenarios. The analysis of plant life-form distribution facilitates the characterization of changes in the vegetation composition in the tropical treeline from a more functional perspective, allowing the assessment of the dynamics of dominant forest elements (such as trees and tall shrubs) above the treeline.
Журнал: Enviromis 2016
Номера страниц: 145-148
Издатель: Томский центр научно-технической информации