Madrid, 13 feb ( EFE).-A team of researchers, with Spanish participation, has concluded that forest ecosystems suffer the consequences of disruption, such as the cutting of trees, for decades, even centuries, and that the current effects of climate change overlapped in the past sequels.
These are some of the findings of a study that publishes the magazine “PNAS”, which also confirms the difficulty to discern, in systems that have been subjected to shocks for a long time between the effects of current climate change and those of past human actions.
Susana Bernal, one of the authors of this paper, explained to Efe that the interesting thing about the study is that it is an “effect clear” of climate change on forest ecosystems, but “not enough” to explain the changes observed.
This is, according to Bernal, because ecosystems have “inertia” and respond slowly to disturbances that have already suffered in the past, and the felling of trees in the early 20th century.
To arrive at these conclusions, researchers analyzed data from the past 50 years – climate, atmospheric deposition, and export of nutrients – and forest inventories of Hubbard Brook Experimental basins, in the northeast of the us for two years.
One of the analyzed variables was the change in the efficiency of inorganic nitrogen, in particular nitrate retention.
According to Bernal, nitrogen is an essential nutrient for all living beings in a system.
In addition to the growth of forests, influencing the capacity of absorption of carbon in ecosystems.
“The ability of forest ecosystems to retain more carbon in the atmosphere is limited by the availability of other essentials, such as nitrogen or phosphorus”, said the researcher, who undertook this work with a scholarship to Princeton University.
American basins mentioned, “perhaps the most studied in the world and that more information is available”, have experienced a drastic decline in the export of nitrogen in recent decades (around 90 per cent), according to Bernal.
Scientists have estimated that as much climate change could explain a 40 per cent of the decline in the export of nitrogen, which usually occurs through the water of the rivers, and that in contrast at least 60 per cent could be result of the long term effects of logging.
Understand the complexity of the interactions between these disturbances and past is today one of the most difficult scientific challenges, said Bernal.
The study also participated the Cary Institute of ecosystem studies (USA). EFE
