Epiphytic bryophytes on European aspenPopulus tremulain old-growth forests in northeastern Finland and in adjacent sites in Russia

Abstract

We studied the occurrence and cover of epiphytic bryophytes and one lichen species (Lobaria pulmonaria (L.) Hoffm.) growing on Populus tremula L. trunks. Our aim was to explore the spatial scales where epiphyte species respond to their environment. At the landscape scale, fragmented Finnish old-growth forests close to the Russian border and farther west in a heavily fragmented landscape were compared with Russian sites with more continuous old-growth forest landscapes to assess the effect of landscape structure on epiphyte assemblages. We studied factors affecting populations at the level of individual sites and local habitat patches within the forests. Twelve sites were surveyed for epiphytes. We estimated epiphyte occurrence from 353 Populus tremula trunks. There seemed to be only minor differences in the structure of epiphyte assemblages between the three landscapes surveyed. Species richness varied also independently of the landscape structure but was positively related to regional Populus tremula abundance (alpha diversity) and the size of the substrate trunk (point diversity). At the regional scale, the most important factor affecting the occurrence of epiphytes was the abundance of Populus tremula. At the local scale, the size of the Populus tremula surveyed and tree density around the trunk surveyed correlated positively with the occurrence of some species. The size and abundance of Populus tremula as well as tree density are the most important factors for maintaining viable populations of the studied species.Key words: biodiversity, boreal forest, Bryophyte, forest management, landscape structure, Lobaria pulmonaria.

The Importance of Large Trees in Shrine Forests for the Conservation of Epiphytic Bryophytes in Urban Areas

“…Contrary to these results, several authors have reported that tree DBH does not strongly impact epiphytic bryophytes [32][33]. The possible explanations for the differences between this study and previous studies are as follow.…”

“…Epiphytic bryophytes are affected by environmental factors such as tree density [15,33], past landscape structure [18,34], bark type [39], silvicultural disturbance [40], air pollution [41], etc. By examining the influence of these factors on bryophytes in future studies, we can propose more effective methods for the conservation of these species.…”

Diversity and distribution of epiphytic lichens and bryophytes on aspen (Populus tremula) in the middle boreal forests of Republic of Karelia (Russia)

“…In addition, lichen epiphytes are useful indicators of forest health because they are sensitive to forest management practices and serve as indicators of air quality (Lesica et al, 1991;Richardson, 1992;McCune, 2000). According to literature, the most important factors influencing epiphytic bryophyte and lichen distribution are forest stand age (Fritz et al, 2008;Mežaka et al, 2010), host tree (Lõhmus et al, 2007;Mežaka et al, 2008;Strazdina, 2010), tree age (Barkman, 1958;Hedenås & Eriksson, 2000;Ojala et al, 2000) and microclimate (John & Dale, 1995).…”

Decreased Epiphytic Bryophyte Diversity on Mt. Odaigahara, Japan: Causes and Implications

“…High tree density and host tree DBH have been suggested to be beneficial for bryophyte diversity, as they provide better microclimates, e.g., humid conditions (Hazell et al, 1998;Ojala et al, 2000;Thomas et al, 2001). Further, the species richness and bryophyte cover may be positively correlated with high host tree DBH because DBH is correlated with bark features (e.g., bark thickness and bark roughness) (Boudreault et al, 2008;Ojala et al,2000).…”

“…Further, the species richness and bryophyte cover may be positively correlated with high host tree DBH because DBH is correlated with bark features (e.g., bark thickness and bark roughness) (Boudreault et al, 2008;Ojala et al,2000).…”