Download Conserving biodiversity and combating desertification: Achieving

Conserving biodiversity and combating
desertification: Achieving synergies
V. Detsis
Harokopio University, Greece
H. Briassoulis
University of the Aegean, Greece
Conserving biodiversity and combating desertification:
Achieving synergies
a Does a general scientific basis exists?
`Can conceptual links be established between these
two issues?
`Do these links correspond to the relevant policies
developed in these fields?
or
a Is a more instrumental approach addressing
the determinants of the two problems better
suited to the present situation and
knowledge status?
`Are there shared determinants of biodiversity
decline and desertification in the Northern
Mediterranean?
Conserving biodiversity and combating desertification:
Achieving synergies
Looking for conceptual links
Biodiversity:
the variability among living organisms from all
sources
a within species, between species and of
ecosystems
Conserving biodiversity and combating desertification:
Achieving synergies
Looking for conceptual links
Desertification:
the process of land degradation in arid, semiarid and dry-subhumid areas;
i.e.
loss
of
biological
and
economic
productivity, as well as loss of land use
complexity that is driven by weather
extremes and human actions
Conserving biodiversity and combating desertification:
Achieving synergies
Looking for conceptual links
Conserving biodiversity and combating desertification:
Achieving synergies
Looking for conceptual links
Disturbance
a Some level of disturbance is necessary for
creating high biodiversity patterns
a The relationship is unimodal making the
effect of altered disturbance patterns on
biodiversity dependent on the starting point
Conserving biodiversity and combating desertification:
Achieving synergies
Looking for conceptual links
a Declining productivity is a consequence
while increased disturbance is a cause of
desertification
a Expected responses of biodiversity to altered
productivity and disturbance patterns are non
monotonous and site specific
Conserving biodiversity and combating desertification:
Achieving synergies
Looking for conceptual links
a Experimental evidence originates from
systems limited in space and time. It is not
known whether the observed patterns can be
(and how) extrapolated to other scales
a Observed patterns tell us nothing about the
nature of species turnover
Conserving biodiversity and combating desertification:
Achieving synergies
Looking for conceptual links
Inconsistency between rersearch results and
policy making:
a Biodiversity policy is concerned with certain
species not with the maximisation of local
diversity - Essentially it concerns regional
diversity
a Biodiversity research is often directed
towards functional groups which are not an
object of biodiversity policy
Conserving biodiversity and combating desertification:
Achieving synergies
Looking for shared determinants in N. Mediterranean
Landscape homogenisation
a Land use change in agricultural areas leads
to a dichotomy between marginal land prone
to abandonment and productive land prone to
intensification.
a The fine-grained mosaic of past uses is
changing to a coarse grained one
Conserving biodiversity and combating desertification:
Achieving synergies
Looking for shared determinants in N. Mediterranean
Abandonment
a Neglect of traditional soil and water
conservation techniques leads to an
increased leakage of materials from the
ecosystem
a Loss of species associated with traditional
land use forms
Conserving biodiversity and combating desertification:
Achieving synergies
Looking for shared determinants in N. Mediterranean
Intensification
a Overexploitation of land resources
a Monoculture expansion leading to loss of
species associated with patchy landscapes
or land use forms that seized to exist in a
given area
Conserving biodiversity and combating desertification:
Achieving synergies
Looking for shared determinants in N. Mediterranean
Issues to be considered:
a How to establish the appropriate spatial
scale of any interventions taking into
account the natural and social mosaic of the
Mediterranean region
a How to elaborate compromises and
optimised solutions that will serve
reasonably well both targets
Conserving biodiversity and combating desertification:
Achieving synergies
Conclusion
a The present state of scientific knowledge
does not allow for the establishment of
generally valid links between biodiversity and
desertification issues
a The establishment of a set of shared
determinants that influence both issues is
possible for Northern Mediterranean
Conserving biodiversity and combating desertification:
Achieving synergies
Conclusion
Synergies can be achieved through mitigation
measures that focus on site-specific
manifestations of these determinants as well
as their possible combinations