INVESTIGADORES
PIÑEIRO Gervasio
artículos
Título:
Land cover and precipitation controls over long-term trends in Carbon gains in Uruguay
Autor/es:
TEXEIRA, M.; OYARZABAL, M.; PIÑEIRO, G.; BAEZA, S.; PARUELO, J.M.
Revista:
Ecosphere
Editorial:
Ecological Society of America
Referencias:
Año: 2015
ISSN:
2150-8925
Resumen:
Carbon gains are a key aspect of ecosystem functioning since they represent approximately the energy available for heterotrophs. Carbon gains (or gross primary production) are strongly correlated with other ecosystem attributes such as secondary production and also provide the basis for the provision of many ecosystem services. Given the documented dependency of carbon gains with annual precipitation, we expect that altered precipitation regimes, such as those projected by climate models, will have a significant impact on carbon gains, but also depending on land use cover changes. We constructed, derived from different sensors on board satellites, a novel spectral long-term (1981-2011) database of the fraction of photosyntetically active radiation intercepted by vegetation (fPAR). We used fPAR as a proxy of carbon gains in order to study long-term trends in carbon gains and its spatial (?spatial models?) and temporal (?temporal models?) relationships with precipitation and land cover patterns in Uruguay. We found that carbon gains of native forests and afforestations exhibited the strongest positive spatial response to precipitation, whereas crops and rangelands the weakest. In addition, we found that the temporal response of carbon gains to precipitation was strong and positive for all land uses.. Besides these relationships between precipitation and carbon gains, and considering that there was no clear trend in precipitation during the period analysed, we found a strong negative trend in carbon gains through time, particularly in rangelands of the ?Northern Campos? of Uruguay, where these trends represent a decrease between 10% and 25% of the annual aboveground net primary production. On the other hand, positive trends in carbon gains through time were associated to crops, afforestation and native forests in other regions of the country. Therefore, during the period analyzed, land cover had a stronger influence on the observed trends in carbon gains than precipitation.