Cross Taxon Congruence Between Lichens and Vascular Plants in a Riparian Ecosystem

Abstract

Despite that congruence across taxa has been proved as an effective tool to provide insights into the processes structuring the spatial distribution of taxonomic groups and is useful for conservation purposes, only a few studies on cross-taxon congruence focused on freshwater ecosystems and on the relations among vascular plants and lichens. We hypothesized here that, since vascular plants could be good surrogates of lichens in these ecosystems, it would be possible to assess the overall biodiversity of riparian habitats using plant data only. In this frame, we explored the relationship between (a) species richness and (b) community composition of plants and lichens in a wetland area located in central Italy to (i) assess whether vascular plants are good surrogates of lichens and (ii) to test the congruence of patterns of species richness and composition among plants and lichens along an ecological gradient. The general performance of plant species richness per se, as a biodiversity surrogate of lichens, had poor results. Nonetheless, the congruence in compositional patterns between lichens and vascular plants varied across habitats and was influenced by the characteristics of the vegetation. In general, we discussed how the strength of the studied relationships could be influenced by characteristics of the data (presence/absence vs. abundance), by the spatial scale, and by the features of the habitats. Overall, our data confirm that the more diverse and structurally complex the vegetation is, the more diverse are the lichen communities it hosts.

Effect of Invasive Alien Species on the Co-Occurrence Patterns of Bryophytes and Vascular Plant Species—The Case of a Mediterranean Disturbed Sandy Coast

“…Despite this information, few examples deal with dune ecosystems [11]. Cross-taxon studies exploring covariation patterns between vascular plants and bryophytes are scarce and mainly focused on forest ecosystems [12][13][14][15][16] and nival and riverine habitats [17], showing contrasting results [14].…”

Practice Must Be Backed up by Theory! A Special Issue on Plant Community Ecology

“…Conservation requires a thorough knowledge of the spatial distribution of biodiversity, and this is still a work in progress for taxa such as cryptogams and lichens. Congruence across taxa has been proved as an effective tool to provide insights into the processes structuring the spatial distribution of taxonomic groups and it is useful for conservation purposes; yet, only a few studies on cross-taxon congruence have focused on the relationships among vascular plants and other groups [10,11]. In this SI, Marignani et al [12] estimate the congruence pattern between vascular plants and bryophytes' diversity in a coastal sand dune system, together with the assessment of the effects of the occurrence of invasive alien species on the two taxa.…”

Lichen and Lichenicolous Fungal Communities Tested as Suitable Systems for the Application of Cross-Taxon Analysis

“…There are case studies in which, using the cross-taxon method, weak evidence of consistent patterns justifies the use of one taxon as a surrogate to predict patterns for other taxonomic groups [26,32,33]. Only a pair of previous studies considered lichens in a cross-taxon analysis [34,35] but neither treated them as surrogate organisms. Here, we focus on the group of symptomatic lichenicolous fungi and their lichen host species and use the second as a predictor to infer the biodiversity of the first.…”