Environmental factors and ground disturbance affecting the composition of species and functional traits of ground layer lichens on grey dunes and dune heaths of Estonia

Abstract

A unique, species-rich and endangered lichen biota can be found on European coastal and inland sand dunes. However, it is increasingly affected by natural succession as well as by anthropogenic disturbances. We studied lichen diversity on the grey dunes and dune heaths of coastal and inland regions of Estonia. A total of 28 study plots were investigated; in each 0.1 ha study plot general environmental variables and anthropogenic disturbances were described and all epigeic lichen species were identified. We found 66 lichenized fungus (lichen) species, including several rare and ten red-listed lichens. Multivariate analysis (DCA, CCA) was performed to examine gradients in species composition and to relate variation in species data to environmental factors. In addition, we used redundancy analysis (RDA) to relate variation in species' trait composition to environmental factors. Species composition on grey dunes differed significantly from that on dune heaths. The characteristic species for grey dunes are, besides several Cladonia species, foliose lichens, e.g. Hypogymnia physodes, Parmelia sulcata and Peltigera spp. Also species' traits composition was different for either habitat, indicating that sorediate lichens, foliose lichens, lichens with cyanobacterium as the main photobiont, and sparsely branched Cladonia species dominate on grey dunes, while esorediate, green-algal, crustose and richly branched fruticose lichens are common on dune heaths. Soil pH was the most essential environmental variable for determining both species composition and species' traits composition. The composition of lichen species was also significantly influenced by forest closeness, soil Mg content and cover of bare sand; the effect of ground disturbances was low compared to the effect of these environmental factors. To protect and conserve the species-rich lichen biota, it is necessary to protect the dune habitats from building activity, to avoid overtrampling in recreation areas and to regularly remove shrubs and trees.

Specialist taxa restricted to threatened habitats contribute significantly to the regional diversity of Peltigera (Lecanoromycetes, Ascomycota) in Estonia

“…Dunes supported the high diversity of Peltigera species, presumably partly because of the highly variable Ca content of sand (Fig. S4E) but also because of favourable light conditions and weak competition from vascular plants (Jun and Rozé 2005;Ketner-Oostra et al 2012;Jüriado et al 2016). Also the relatively high Peltigera diversity in roadside habitats may be largely explained by the presence of limestone as limestone gravel is widely used for road construction in Estonia.…”

“…The dune grasslands were located along the seashore in Western Estonia and along the shores of Lake Peipsi in the northeast. The pioneer grasslands and the herb-rich grasslands prevailed on grey dunes (called 'grey' partly because of their dense lichen cover); communities of Calluna vulgaris and Empetrum nigrum were found on dune heaths (Jüriado et al 2016). The roadside grasslands were mesic and xeric grasslands in the immediate vicinity of paved or unpaved roads.…”

“…Both roadsides and dunes are affected by relatively high levels of disturbance and human activity. Periodic removal of trees from dunes (Riksen et al 2006;Jüriado et al 2016) and mowing of roadside meadows (Parr and Way 1988) is needed for the long-term preservation of these habitats and the species diversity of their terricolous lichen communities.…”

Red List of Estonian lichens: revision in 2019

“…Jüriado et al, 2003;Lõhmus & Kruustük, 2010;Lõhmus & Lõhmus, 2011;Degtjarenko et al, 2016;Marmor et al, 2017;Jüriado & Paal, 2019), while dry alvar grasslands with very thin soil layer and sand dunes are suitable for ground layer community taxa (e.g. Leppik et al 2013Leppik et al , 2015Jüriado et al, 2016). Therefore, the main threat factors of Estonian lichens tend to be forest cutting (important factor for 96 species) and overgrowing of dunes and alvars due to the cessation of traditional management (important for 70 species).…”

The pros and cons of being broad: recent and future progress of Nordic Journal of Botany

“…Likewise, our taxonomic contributions cover all major vascular plant groups from orchids (Hall et al , Sanguinetti , Szlachetko and Kolanowska , Kumar et al ) and bamboos (Nguyen and Tran ) to Asteraceae (Øllgaard , Attar et al , Negaresh and Rahiminejad , Nilsson and Tyler ). Mycology and lichenology also has a natural position in our content, with important recent contributions such as those by Ekman (), Jüriado et al (, ), Hestmark (), Liu and He () and Spirin et al (). Algaeology has been represented by contributions about chrysophytes (Němcová , Wei et al ), and bryology by a description of a new species of Didymodon (Kou et al ).…”