BADARAU, ALEXANDRU - SABIN*, MIHAI CONSTANTINESCU, STEFAN DEZSI, and FLORIN PENDEA. Babesh - Bolyai University, Faculty of Geography, str. Clinicilor 5-7, 3400 Cluj-Napoca, Romania. - Biogeography and degradation of the grasslands dominated by Stipa sect. Stipa species in the Transylvanian forest - steppe. Consequences upon the evolution of the regional landscape.
The Transylvanian Basin is a tectonic depression in central Romania
that has a hilly relief and is surrounded by the Carpathian Mountains.
The western part of this basin, because it is in the rain shadow of
the mountains, is semiarid and has forest-steppe type landscape. Among
the typical components of the area vegetation are grasslands dominated
by Stipa sect. Stipa. These grasslands fall into two
categories: xerophytic grasslands dominated by Stipa
pulcherrima and St. lessingiana and mesophytic grasslands
with S. stenophylla that have a "meadow steppe" type
of vegetation. These grasslands are similar to those in other portions
of the western Palearctis, but have a unique mixture of
Submediterranean and Central European species. In addition, our data
suggest that they are not saturated, possibly because some species
have failed to cross the Carpathian Mountains. In the past, botanists
have not distinguished between these two types of grasslands, whether
in relatively pristine condition or in various stages of degradation.
We shall demonstrate that they are distinct, using ordination
techniques and a database containing more than 350 releves sampled by
our team. In addition, we shall show that indices of biodiversity
provide clear indications of the extent to which such grasslands have
been degraded and the entropy of their structure increased by human