Adil GÜNER, Vehbi ESER - optima

Oral Lectures
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CONSERVATION OF MEDITERRANEAN GYPSUM STEPPES:
UNDERSTANDING COMMUNITY STRUCTURE AT HIERARCHIZED
SPATIAL AND TIME SCALES
Adrian ESCUDERO
Biodiversity and Conservation Unit, Dep. Biology and Geology. Universidad Rey Juan Carlos, Móstoles, Madrid,
Spain. adrian.escudero@urjc.es
In order to mitigate the impact of global change drivers on specialized soil systems such as those
occurring on semiarid gypsum outcrops, it is very critical to know how they vary in time and
space. Recently we have experimentally showed how gypsophytes respond to these changes and
more specifically how do different drivers interact on plant performance. However it is prioritary
to scale up this knowledge to the community level in order to develop a proper management at
the whole system level. With this in mind we have explored how the structure and composition of
different community attributes of these systems including biological soil crusts and plant
communities varies in space and time. We have studied a detailed chronosequence spanning for
almost 100 years with more than sixty sites with different ages from abandonment. In all these
sites the complete plant community was surveyed together with their permanent soil seed banks
and a complete set of predictors. In parallel we have surveyed the structure and composition of
the biological components of these communities at several spatial scales (regional to very local)
and related to different surrogates of ecosystem functioning.
Taken all together we found that these steppes are able to rapidly recover from disturbance.
Secondary succession on specialized Mediterranean soils does not follow the widely described
‘‘amelioration’’ process in which soil features and composition are closely related over time. In
addition we also concluded that restrictive soil conditions control both structure and functioning
of mature communities at hierarchized scales, independently of the nature of the community
compartment.
Keywords: Biotic interactions, Environmental filtering, Gypsum vegetation, Land abandonment,
Succession
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