106
higher number of vascular and heart diseases, which were fatal in a considerable
number of cases (WHO 2017). Subsequent studies, published in over 500 scientific
publications, confirmed Nylander’s conclusions.
To date, several different methods of lichen indication of air quality were developed and accepted. However, each of these methods has the same goal of precisely
assessing the quality of the air; therefore all of the abovementioned methods show
identical results. The lichen community approach is one of the widely used
approaches.
Lichen communities are made up of a number of different lichen species and a
whole range of biotic interactions that take place between them. The richness and
number of species in lichen communities depend on the ecological conditions of the
environment as well as the habitat itself. In altered habitat conditions, often caused
by the presence of a pollutant, lichen communities may be composed of individual
species, and such communities are called monospecific communities. The composition of a community also depends on the species’ ability to respond to various conditions of the habitat (Parmesan and Yohe 2003; Root et al. 2003). While some
species, which are distinguished by a pronounced presence and frequency even in
altered environmental conditions, are characterized as tolerant and do not have any
specific requirements, such as Xanthoria parietina, others are very rare and relatively poorly represented and therefore do not require specific environmental
conditions.
Some lichens have limited dispersal abilities. The patterns of distribution, abundance, and interactions of species occur on different spatial scales and are influenced by ecological processes which also operate on multiple scales (Chase and
Leibold 2002). There are two types of scales: local and regional. At the local scale,
key factors for the composition of different lichen communities are niche differentiation, resource heterogeneity, and the interactions between competing species. On
the other hand, the regional scale includes interactions of species that affect colonization and extinction dynamics among local communities.
Analyses of the lichen community show lichen responses to environmental factors (Koch et al. 2019; Aragon et al. 2019). The lichens shown react to environmental factors that operate on different spatial scales, and each factor has a particular
range of influence, which is a consequence of different pollutant scattering patterns
(Pinho et al. 2011). The composition of the lichen community depends on the variation of the microclimate. The microclimate is determined by the interactions
between the regional climate, tree architecture, and bark properties. Furthermore, if
we study the epiphytic lichen communities, we can notice that the bark of the tree,
where the lichens can be found, has a major impact on the composition of the communities. The bark on the upper part of the trunk is generally smoother than the bark
on the base of the tree. Most studies show that the pH value of the bark is a very
important factor which affects the composition of lichen communities (van Herk
2001). Gombert et al. (2004) found that higher IAP (index of atmospheric purity)
values were associated with nitrophytic and neutrophytic species, while sites with
lower IAP values showed a predominance of acidophytic or oligotrophic species.
S. Ristić et al.
higher number of vascular and heart diseases, which were fatal in a considerable
number of cases (WHO 2017). Subsequent studies, published in over 500 scientific
publications, confirmed Nylander’s conclusions.
To date, several different methods of lichen indication of air quality were developed and accepted. However, each of these methods has the same goal of precisely
assessing the quality of the air; therefore all of the abovementioned methods show
identical results. The lichen community approach is one of the widely used
approaches.
Lichen communities are made up of a number of different lichen species and a
whole range of biotic interactions that take place between them. The richness and
number of species in lichen communities depend on the ecological conditions of the
environment as well as the habitat itself. In altered habitat conditions, often caused
by the presence of a pollutant, lichen communities may be composed of individual
species, and such communities are called monospecific communities. The composition of a community also depends on the species’ ability to respond to various conditions of the habitat (Parmesan and Yohe 2003; Root et al. 2003). While some
species, which are distinguished by a pronounced presence and frequency even in
altered environmental conditions, are characterized as tolerant and do not have any
specific requirements, such as Xanthoria parietina, others are very rare and relatively poorly represented and therefore do not require specific environmental
conditions.
Some lichens have limited dispersal abilities. The patterns of distribution, abundance, and interactions of species occur on different spatial scales and are influenced by ecological processes which also operate on multiple scales (Chase and
Leibold 2002). There are two types of scales: local and regional. At the local scale,
key factors for the composition of different lichen communities are niche differentiation, resource heterogeneity, and the interactions between competing species. On
the other hand, the regional scale includes interactions of species that affect colonization and extinction dynamics among local communities.
Analyses of the lichen community show lichen responses to environmental factors (Koch et al. 2019; Aragon et al. 2019). The lichens shown react to environmental factors that operate on different spatial scales, and each factor has a particular
range of influence, which is a consequence of different pollutant scattering patterns
(Pinho et al. 2011). The composition of the lichen community depends on the variation of the microclimate. The microclimate is determined by the interactions
between the regional climate, tree architecture, and bark properties. Furthermore, if
we study the epiphytic lichen communities, we can notice that the bark of the tree,
where the lichens can be found, has a major impact on the composition of the communities. The bark on the upper part of the trunk is generally smoother than the bark
on the base of the tree. Most studies show that the pH value of the bark is a very
important factor which affects the composition of lichen communities (van Herk
2001). Gombert et al. (2004) found that higher IAP (index of atmospheric purity)
values were associated with nitrophytic and neutrophytic species, while sites with
lower IAP values showed a predominance of acidophytic or oligotrophic species.
S. Ristić et al.