The latest paper
of our research team is about the contribution of Quaternary
paleoecology to nature conservation, and will be published soon in Quaternary Science Reviews
as an invited review. This paper analyzes the role of paleoecology, as
an ecological discipline, in the understanding of ecological processes
ocurring at time scales beyond human observation capacity, and the
application of this knowledge to nature conservation. Emphasis is on the
responses of organisms and ecosystems to climate changes and fire, as
two of the main current and near-future threats. The review is not
limited to the usual theoretical aspects of the problem -which are also
considered- but it is an attempt to show how paleoecology can contribute
to address real environmental problems. At the end, several case
studies from our own experience in the Neotropics are provided, in order
to illustrate the usefulness of the main proposals discussed the
general part. The paper is dedicated to Margaret Bryan Davis, one of the pioneers and more influential reserachers in the field. The summary of the paper is reproduced below.
Summary: Palaeoecology,
as an ecological discipline, is able to provide relevant inputs for
conservation science and ecosystem management, especially for issues
involving long-term processes, such as ecological succession, migration,
adaptation, microevolution, and extinction. This use of palaeoecology
has been noted for several decades, and it has become widely accepted,
especially in the frame of ongoing and near-future global warming and
its potential biotic consequences. Selected palaeoecological insights of
interest for conservation include the following: 1) species respond in
an individualistic manner to environmental changes that lead to changes
in community composition, suggesting that future ecosystems would have
no modern analogues; 2) in the short-term, acclimation is more likely a
response of species that are expected to persist in the face of global
warming, but the possibility of evolutionary change linked to the
existence of pre-adapted genomes cannot be dismissed; 3) species unable
to acclimate or adapt to new conditions should migrate or become
extinct, which has been observed in past records; 4) current extinction
estimates for the near-future should be revised in light of
palaeoecological information, which shows that spatial reorganisations
and persistence in suitable microrefugia have been more common than
extinction during the Quaternary; 5) biotic responses to environmental
changes do not necessarily follow the rules of equilibrium dynamics but
depend on complex and non-linear processes that lead to unexpected
“surprises”, which are favoured by the occurrence of thresholds and
amplifying positive feedbacks; 6) threshold responses can cause the
movement of ecosystems among several potentially stable states depending
on their resilience, or the persistence of transient states; 7) species
and their communities have responded to environmental changes in a
heterogeneous fashion according to the local and regional features,
which is crucial for present and future management policies; 8) the
global warming that occurred at the end of the Younger Drays cold
reversal (ca. 13.0 to 11.5 cal kyr BP) took place at similar rates and
magnitudes compared to the global warming projected for the 21st
century, thus becoming a powerful past analogue for prediction
modelling; 9) environmental changes have acted upon ecosystems in an
indirect way by modifying human behaviour and activities that, in turn,
have had the potential of changing the environment and enhancing the
disturbance effects by synergistic processes involving positive
feedbacks; 10) the collapse of past civilisations under climate stress
has been chiefly the result of inadequate management procedures and
weaknesses in social organisation, which would be a warning for the
present uncontrolled growth of human population, the consequent
overexploitation of natural resources, and the continuous increase of
greenhouse-gas emissions; 11) the impact of fire as a decisive
ecological agent has increased since the rise of humans, especially
during the last millennia, but anthropic fires were not dominant over
natural fires until the 19th century; 12) fire has been an
essential element in the development and ecological dynamics of many
ecosystems, and it has significantly affected the worldwide biome
distribution; 13) climate-fire-human synergies that amplify the effects
of climate, or fire alone, have been important in the shaping of modern
landscapes. These general paleoecological observations and others that
have emerged from case studies of particular problems can improve the
preservation of biodiversity and ecosystem functions. Nature
conservation requires the full consideration of palaeoecological
knowledge in an ecological context, along with the synergistic
cooperation of palaeoecologists with neoecologists, anthropologists, and
conservation scientists.
 |
| Fire in the Gran Sabana (SE Venezuela) |
Reference:
Vegas-Vilarrúbia, T., Rull, V., Montoya, E. & Safont, E. 2011. Quaternary palaeoecology and nature conservation: a general review with some examples from the Neotropics. Quaternary Science Reviews, doi: 10.1016/j.quascirev.2011.05.006.
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