Global warming impacts the main species of shrubs in Serra da Estrela and the growth of pastures in the region, indicating the first results of the ESTRELA research project, led by a team from the University of Coimbra (UC).
The project “ESTRELA – Effect of global warming on the diversity and functioning of the alpine ecosystems of Serra da Estrela” is coordinated by Susana Rodríguez Echeverría, Cristina Nabais and Marta Correia, from the Functional Ecology Center of the Department of Life Sciences, Faculty of Sciences and Technology at the University of Coimbra (FCTUC), and has as a partner the Serra da Estrela Interpretation Center (CISE) of the Municipality of Seia. It also has the support of Geopark Estrela and the Institute for the Conservation of Nature and Forests (ICNF).
The objective is to study the effect of global warming, a primary factor of climate change, on the functioning and diversity of the ecosystems of the Serra da Estrela upper plateau, especially in the communities of shrubs and cervunais (pastures where cervum, a plant of the family grasses that grow spontaneously in Serra da Estrela).
The coordinators of the project, which started in 2020, explain that their work has focused on the study of the «growth rings of juniper (Juniperus communis ssp alpina) and Pyrno (Cytisus oromediterraneus), typical species of a high mountain in the Iberian Peninsula and which in Portugal appear almost exclusively in Serra da Estrela».
The results obtained so far indicate «a greater growth of these shrubs (juniper and pygmy) in recent years due to the increase in minimum temperature in spring and autumn, which results in a longer growing season», reports Susana Rodríguez Echeverría, clarifying that, yet, «there are differences between species. Juniper starts to grow earlier due to the spring temperature rise, while the pygmy does not respond to the spring temperature, but delays the end of growth due to the autumn temperature rise. The increase in the minimum temperature in summer and the decrease in precipitation in winter negatively affect the juniper growth».
This means, adds the researcher from the Center for Functional Ecology at FCTUC, that «it is necessary to take into account the seasonal pattern of climate change to understand the effects on the diversity and functioning of ecosystems».
The team is also carrying out an experimental study of temperature manipulation in five cervunais, having already proven that «the increase in temperature leads to greater growth of pastures, but that depends on the availability of water and soil conditions. It is still being studied whether this rapid growth, in response to higher temperatures, affects the nutritional quality of these pastures», reveals Susana Rodríguez Echeverría.
The researcher also mentions that, in addition to the rapid response of these plant species to warming, the team has observed «the need to carry out small-scale monitoring of climatic conditions in parallel with ecological studies that allow a better inference of the responses of ecosystems to the climate», noting that «there are few ecological and functional studies in Serra da Estrela, and the data provided by the Penhas Douradas observatory or by current climate models cannot collect the diversity of top climates and microclimates in Estrela».
The ESTRELA project is co-financed by the European Regional Development Fund (ERDF), through the Portugal 2020 program, under the Center’s Regional Operational Programme, and by the Foundation for Science and Technology (FCT) through national funds (PIDDAC).