Phorophyte specificity and environmental parameters versus stochasticity as determinants for species composition of corticolous crustose lichen communities in the Atlantic rain forest of northeastern Brazil

Abstract

A transect of 47 mature trees was studied within an Atlantic rain-forest plot in northeastern Brazil to determinate effects of phorophyte specificity and environmental parameters vs. stochasticity on the structure of corticolous, crustose microlichen communities. A total of 150 lichen species was found, most being rare to extremely rare. Multivariate analysis of sample plots indicated subtle phorophyte preferences among certain lichen species, corresponding to differences in bark pH, degree of bark shedding, density and size of bark lenticels, and presence of milk sap. Individual and multiple regressions revealed correlations between lichen species richness; respectively, area cover and bark pH (negative); density and size of bark lenticels (negative); degree of bark shedding (negative); presence of milk sap (positive); and diffuse site factor (positive). No strongly delimited lichen communities were detected, but cluster analysis revealed three main groups and six subgroups with slightly different lichen species composition, each one with characteristic indicator species but with highly variable overall species composition. Beta diversity was high among samples and lacked spatial structure. However, beta diversity was significantly lower among samples belonging to the same tree species, independent of their spatial arrangement. It was concluded that community formation in tropical rain-forest understory lichens subtly correlates with two main environmental factor complexes-phorophyte bark characteristics and microclimate-but is to a large extent determined by the stochastic effects of species dispersal, especially of rare species.Lichens occur in practically all ecosystems-from hot and cold deserts, to lush tropical rainforests and even in aquatic and marine environments (Henssen and Jahns

How diverse is the lichenized fungal familyTrypetheliaceae(Ascomycota: Dothideomycetes)? A quantitative prediction of global species richness

“…We assigned each vegetation type (Bailey province) a score corresponding to the richness of Trypetheliaceae expected within that vegetation type (Table 2; see Supplementary Material B, available online), using data from quantitative studies that include Trypetheliaceae to rank vegetation types (provinces) according to expected diversity (Cornelissen & ter Steege 1989;Montfoort & Ek 1990;Komposch & Hafellner 1999, 2003Nöske & Sipman 2004;Holz & Gradstein 2005;Lakatos et al 2006;Cáceres et al 2007Cáceres et al , 2008Aptroot et al 2008;Rivas Plata et al 2008). In Graphidaceae, vegetation types that contribute uniquely and substantially to overall species richness are the rainforest and rainforest mountain divisions and the savannah and savannah mountain divisions where they are found mainly in the rainforest canopy (Lücking et al 2014a).…”

“…The most species-rich lichen communities are found in tropical rainforests and various types of dry forest and climatic and edaphic savannah vegetation, including the Brazilian Cerrado and Caatinga, where they cover the bark and leaves of trees and shrubs from the shady understorey to the exposed canopy (Cornelissen & ter Steege 1989;Sipman & Harris 1989;Montfoort & Ek 1990;Marcelli 1992;Wolf 1993;Biedinger & Fischer 1996;Komposch & Hafellner 1999, 2003Lücking 2001Lücking , 2008Nöske & Sipman 2004;Holz & Gradstein 2005;Lakatos et al 2006;Cáceres et al 2007Cáceres et al , 2008. Such communities hold various 'richness' records, from the most species on single leaves (50-82 in Costa Rica and Ecuador; Lücking & Matzer 2001), to the most species on a single tree (173 in Papua New Guinea; Aptroot 1997), to the most species within a given plot (up to 600 in Costa Rica; Lücking et al 2011).…”

Epiphytic microlichens as indicators of phytosociological differentiation between Caatinga and Brejos de Altitude

“…The sampling method was adapted from Cáceres et al (2007), according to which five 100 m long parallel transects were delimited in each locality, and each transect was placed 25 m apart from one another. Along each transect a sampling point was marked every 10 m, totaling 50 points for each studied area.…”

Sampling and Interpreting Lichen Diversity Data for Biomonitoring Purposes

“…Bark-pH may decrease with increasing tree circumference (Bates 1992;Kuusinen 1994) and/or age (Ellis and Coppins 2007), or pH may increase with circumference (Jüriado et al 2009) and/or tree age (Fritz et al 2009). Also, bark texture was found to be an important tree species factor influencing lichen diversity (Bates 1992;Cácares et al 2007;Ranius et al 2008;Fritz et al 2009). This is subject to an effect of tree age/size (dbh) and an interaction with vertical height on the trunk (Johansson et al 2007;Ranius et al 2008;Fritz 2009), and it is related with a species-specific relationship between bark roughness and tree age/size (Uliczka and Angelstam 1999).…”