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P. Matos et al. 2010. Can lichen functional diversity be a good indicator of macroclimatic conditions
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to be declining, while (sub)tropical species are invading, independent of nutrient demands and
decreasing SO 2 emissions (van Herk et al. 2002). In Western Europe, the number of epiphytic
species appears to be increasing rather than declining, as a result of global warming (Aptroot
and van Herk 2007). Model predictions indicate major shifts in the distribution of lichen species
(Ellis et al. 2007; Giordani and Incerti 2008).
Despite many authors consider that climate change will affect lichens by shifting their
communities, none of them tested this hypothesis explicitly, because these studies were
performed considering either total species richness or individual species response. Recent
studies (Giordani and Incerti 2008) focused on functional-diversity, but used posteriori selected
guilds, that were based on the pattern of environmental variables. Because it was based on
posteriori classification, it is strongly dependent on local communities, and thus cannot have a
broader applicability. To overcome this problem and find a more universal indicator, we have
made use of a priory classification of functional-diversity based on their humidity requirements.
The use of lichen functional groups was shown to be better related with several environmental
gradients than total biodiversity, at least for NH 3 air pollution (Pinho et al. 2009). Moreover,
functional-groups of species have been successfully used to disentangle or analyze in
simultaneous the influence of multiple environmental factors (Stofer et al. 2006; Pinho et al.
2008a).
In this work we propose to study the effect of macroclimate on total lichen richness, abundance
and on the shifts of lichen functional groups in a regional area ranging from the more humid
areas in coastal central Portugal to the SE of the Alentejo in semi-arid areas. This work intends
to be a first approach to find the best ecological indicators of macroclimatic changes for
Mediterranean areas.
2. Methodology
2.1 Study area
The study was conducted in three different areas of continental Portugal, covering three
different macroclimatic regions (Figure 1). The area A is a Quercus faginea wood located in the
west central part of Portugal, within the Natural Park of Serra d’Aire e Candeeiros. This area
belongs to the Mesomediterranean belt, from the Coastal Lusitano-Andalusian province (Rivas-
Martinéz and Rivas-Saenz 2009). It has an annual average temperature that ranges from 15 to
17.5 ºC and an annual average precipitation between 1400 and 1600 mm (averages from 1931 to
1960, (IA 2010)). The area B is located in the southwest coast of Portugal, facing the Atlantic
Ocean to the west. It’s a cork oak wood (Quercus suber) with annual average temperature
between 16 and 17.5 ºC, and average annual precipitation between 600 and 1000 mm (averages
from years 1931 to 1960 (IA 2010)). This area is in the Termomediterranean belt, within the
Coastal Lusitano-Andalusian province (Rivas-Martinéz and Rivas-Saenz 2009). The area C is a
holm oak wood (Quercus ilex) located southeast from the former area. This area belongs to the
Mesomediterranean belt and is placed in the Mediterranean West Iberian province (Rivas-
Martinéz and Rivas-Saenz 2009) and its climate is semi-arid warm, with annual average
precipitation between 500 and 600 mm and average temperatures ranging between 16 and 17.5
ºC.
2.2 Biodiversity data collection and calculation of lichen-diversity variables
Lichen diversity was sampled in 149 sites, 29 sampling sites in the area A, 77 sampling sites in
the area B (Pinho et al. 2008a,b) and 43 sampling sites in the area C. The sampling was carried
according to the method described in Asta et al. (2002).
For each site we calculated several lichen-variables: i) total number of species; ii) LDV, lichen
diversity value, which is the sum of all species frequency within the grid. Additionally LDV
Forest Landscapes and Global Change-New Frontiers in Management, Conservation and Restoration. Proceedings of the IUFRO Landscape Ecology
Working Group International Conference, September 21-27, 2010, Bragança, Portugal. J.C. Azevedo, M. Feliciano, J. Castro & M.A. Pinto (eds.)
2010, Instituto Politécnico de Bragança, Bragança, Portugal.