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PLANT LIFE FORMS AS INDICATORS OF THE CONSERVATION STATUS OF SEMINATURAL DRY GRASSLANDS
R. LABADESSA, P. MAIROTA
Department of Agro-Environmental and Territorial Sciences, University of Bari "Aldo Moro", Via Orabona
4, 70125 Bari, Italy, [email protected]
The impact of land use change, threatening many ecosystems of high conservation value, has
stimulated studies aiming at developing effective strategies for habitat monitoring. In this regard,
the use of synthetic indicators as proxy measures of ecosystem conditions and impacts due to
human pressures represent an alternative and efficient method to monitor change.
This study is aimed at examining the usefulness of Raunkiaer's plant life form classification to
identify habitat changes in semi-natural dry grasslands of Alta Murgia National Park (southeast
Italy).
Cover values of herbaceous plant species were surveyed within 30 grassland sites, representative of
different degrees of habitat degradation and fragmentation. Species were classified according to
their life form and main syntaxonomic category to which they belong. Bivariate correlation was
then performed between the cover value of life forms and that of the characteristic species of the
syntaxonomic groups.
As a result, life forms provided significant inferences on the conservation status of plant
communities. High cover values of chamaephytes and perennial grasses were correlated with well
preserved sub-mesophilic grasslands, while biennial forbs and annual grasses were associated with
degraded ruderal communities. Based on these significant relationships, a synthetic index (Q) of the
conservation state of perennial grasslands was thus devised by summing the cover value of
chamaephytes and perennial grasses and subtracting that of biennials and annual grasses.
Q index resulted effective in describing the relative quality of sub-mesophilic perennial
communities, mostly referred to endemic vegetation of conservation concern. With regard to its
applicability, this index may provide a readily recorded and consistent method of obtaining
information on plant community characteristics, which is needed for planning cost-effective and
replicable protocols for habitat monitoring. Indeed, this is relevant from an operational perspective,
as life forms can be monitored in the field without the need for standard vegetation surveyed.
These results are of particular importance within the context of biodiversity and habitat change
mapping, underlining the usefulness of morpho-functional classifications of species for the
interpretation of ecosystem dynamics.