Changes in stand structure due to the cessation of traditional land use in wooded meadows impoverish epiphytic lichen communities

Abstract

Wooded meadows with a history of traditional land use over thousands of years support a great diversity of various taxa. Today, however, high-species-rich communities in wooded meadows are threatened because of the cessation of traditional management in large areas. We studied lichen communities on 136 deciduous trees (Betula spp., Fraxinus excelsior and Quercus robur) in 12 wooded meadows in three regions of Estonia, and assessed the effect of habitat change due to the abandonment of traditional management on epiphytic lichen species composition, considering factors on three spatial scales: regional, habitat and individual tree. The variation partitioning approach in partial Canonical Correspondence Analysis (pCCA) revealed that most of the variation in species composition is described by the species of host tree and tree bark pH. Other tree level variables, foremost tree diameter, described as much of the compositional variation as geographic location (region) or environmental conditions in wooded meadows. Of the environmental factors studied, woodland canopy cover is the strongest predictor of the change in epiphytic lichen species composition from the community type of semi-open wooded meadows to species-poor communities characteristic of secondary forest. General Linear Model (GLM) analysis of the abundance of the 35 most frequently observed lichen species revealed that more than half of them (21) are influenced by site openness (canopy cover and/or undergrowth density), showing that increasing canopy cover has a negative effect on the abundance of epiphytic lichen species characteristic of traditionally managed semi-open wooded meadows. The results emphasize that the preservation of large old deciduous trees of various species and the maintenance of the semi-open structure of stands are vitally important for the protection of epiphytic lichen communities in wooded meadows.

Ecological pattern of lichen species abundance in mixed forests of Eastern Romania

“…Similar results have been obtained by Bollinger et al (2007) in Switzerland, Leppik et al (2011) in Estonia and Ekman et al (2013) in Sweden, who found that crustose lichen species are related to trees with smooth bark, among which Fagus sylvatica is one of the host trees.…”

“…At the tree level, the bark morphology, diameter, competition with other epiphytes (Leppik et al 2011), bark pH (Mistry & Berardi 2005, Thor et al 2010) and aspect (Morley & Gibson 2010) are attributes which influence epiphytic lichen species.…”

Synecological structure of the lichen synusiae within forest natural reserves from the Moldavian Plateau (Romania)

“…Thus, lichens make up ecological groups based upon their shared requirements for a particular rhytidome texture. Leppik et al (2011) emphasized that the most probable causes of such differentiation among tree species are lichen Table 2. The values of Mann-Whitney U test for investigated natural reserves based on relative abundance of lichen species.…”

Sampling and Interpreting Lichen Diversity Data for Biomonitoring Purposes

“…Bark-pH was not found as discriminant parameter among the two tree species. On the contrary, many studies have demonstrated a strong epiphyte response to barkpH, explaining epiphyte community variation compared among tree species in both boreal and temperate systems (Hyvärinen et al 1992;Gauslaa 1995;Kuusinen 1996;Jüriado et al 2009;Lewis and Ellis 2010;Leppik et al 2011). Moreover, intraspecific studies, among boles of the same tree species, have indicated that barkpH/nutrient status may be modified by an interaction with the soil environment (Gauslaa 1995; Gustafsson and Eriksson 1995; Kermit and Gauslaa 2001) and with a subsequent effect on epiphyte community composition.…”