A new study led by Josep Peñuelas and published in Nature Ecology and Evolution reveals that CO2 abundance in the atmosphere no longer has a powerful fertilizing effect on vegetation. The greening that has been observed in recent years is slowing and this will cause CO2 levels in the atmosphere to rise, thus increasing temperatures and leading to increasingly severe changes in climate.
An extensive review of studies and databases reveals that drought and an increase in temperature are already causing species substitutions, greater aridity, higher forest fire risk, lower soil fertility, and lower water availability, among other negative impacts.
The COP21 set the maximum temperature increase for 2100 at 1.5° C. The only scenario which would allow achievement of this goal would require vastly reducing human CO2 emissions, significantly increasing the prominence of renewable energies, and the use of some type of artificial carbon sequestration technology.
The forest treeline shifts upward slower than temperature increase, and it can be hindered by densification of shrubs. A number of factors influence upward forest expansion, including the particular plant species growing near trees, climate change, human activity, and terrain morphology. The Tibetan Plateau, practically devoid of human pressures, offers a pristine area for study
This finding is described in an article including CREAF researchers and coauthors Aitor Ameztegui and Lluís Brotons. The study addresses how the superior limit of forest cover in the Pyrenees has changed over 50 years. According to the study, the tree line has advanced upward an average of 40 meters, one of the main causes of this being decreasing pressures from livestock. Contrary to common thinking to date, climate change may play a much lesser role than previously thought.
Leaf unfolding occurred on average about 4 days earlier every one degree increase in spring temperature between 1980 and 1994, whereas this value dropped to -2.3 days C-1 between 1999 and 2013, a decrease of over 40%. According to this study recently published in the jorunal Nature with the participaction of Josep Peñuelas, researcher from CSIC at CREAF, warmer winters and photoperiod are forcing plants to control their phenology calendars.
A study led by a CREAF-CSIC researcher has outlined a new methodology for describing changes in the life cycle of plants caused by planetary warmingwith higher precision. Daytime, rather than nocturnal temperatures determine phenological changes. The increase in temperatures, leading to an earlier spring, alters the global functioning of ecosystems.
