Perilous
Times and Climate Change
Forest fires around the world, are becoming larger and more
frequent
Posted On: October 24, 2011 - 3:01pm
The study, recently published in the journal Climatic Change, is
the result of an interdisciplinary collaboration between two
researchers: one is UC3M Professor Santiago Fernández Muñoz, who
has worked in the area of geographic history under the direction
of the Universidad Autónoma de Madrid Professor Josefina Gómez
Mendoza; the other is Consejo Superior de Investigaciones
Científicas (CSIC – Spanish National Research Council) ecologist
Juli Pausas. Specifically, the authors constructed a complete
database of historical fires in the province of Valencia in order
to relate them to the evolution of the climate and societal and
territorial transformations in the region. The research that was
carried out provides the most complete series of data on the
evolution of fires in the Mediterranean basin to date.
The conclusion they have reached is that a significant change in
the number and, especially, size of forest fires took place during
the decade of the seventies. This change can be directly related
to the rural exodus and transformation of land use that took place
during that decade. "The depopulation of rural areas resulted in
the abandonment of agricultural spaces that had historically been
interspersed among the forests. Because of this, in the space of a
few years, spaces where there had previously been grain fields
were invaded by highly flammable vegetation in a series of steps
leading toward the Mediterranean forests", explains Professor
Fernández Muñoz.
Research in which scientists from Universidad Carlos III de Madrid
(UC3M) are participating analyzes the causes and characteristics
of fires that have occurred in the Mediterranean basin in recent
decades, and determines that rural exodus and changes in land use
have increased the number and size of these fires.
At the same time, the extraction of firewood decreased drastically
as a consequence of the incorporation of other sources of energy,
and the country witnessed a very relevant transformation in its
rural landscapes, which became "less populated and with fewer
patchworks of land for agricultural use, with more continuous
forest masses and more highly flammable vegetation", clarifies the
expert. In spite of the fact that depopulation and the changes in
land use were gradual, this research has detected a number of
thresholds after which a very significant increase in the number
of fires took place; these numbers fall around a population
density of 0.6 inhabitants per square kilometer.
To carry out this study, the scientists first did basic research
on the incidence of forest fires in the province of Valencia
beginning in 1875. To do this, they reviewed the forest
administration's archives and identified every news item regarding
fires that had appeared in the local newspapers. Thanks to this
work, they were able to elaborate a database with thousands of
records of fires identified by date, location and the surface area
that had burned. Finally, they related all of this information to
socioeconomic variables (evolution of the population, land use,
etc.) and climatic variables (precipitation, temperature), by
applying complex statistical methods to find the connection among
the different variables.
To sum up, what they have found is that the change in the
occurrence of fires that are recorded in the historical research
cannot be explained by the gradual change in climate, but rather
that it corresponds to changes in the availability of fuel, the
use of sources of energy and the continuity of the landscape. This
research, which attempts to explain the evolution of fires, may be
very useful for the management of forest areas prone to fires in
the middle and long term, according to the authors.