Vertical distribution of epiphytic bryophytes and lichens emphasizes the importance of old beeches in conservation

Abstract

During storms in 2005, a number of beech trees fell over at Biskopstorp, SW Sweden, offering the opportunity to study epiphytes along entire stems. In total 16 beech trees in four beech stands representing three different age classes were included. For each tree, 2 m segments from the base to the top were surveyed. In total 115 species were found (76 lichens, 39 bryophytes), of which 30 were considered to be of conservation concern (22 lichens, 8 bryophytes). For lichens significantly more species were recorded above 2 m in height, whereas more bryophytes were recorded below 2 m in height. Certain red-listed lichens were recorded only above 2 m in height on old trees. In a second data set from the same area 140 age-determined beech trees were surveyed for species of conservation concern at the heights 0-2 and 2-5 m, respectively. These species were found almost exclusively on old beech trees, and presence at 2-5 m was recorded, with one exception, only on those trees which also had species of conservation concern at 0-2 m. Records of these species correlated significantly to microhabitat variables, i.e. the presence of rough bark and moss cover higher up the stems on the old trees. This study indicates that surveying only the base in really old beech forests can underestimate both the number of species of conservation concern and their population sizes. However, surveys restricted to the base in rather even-aged beech stands catch a large proportion of the trees with species of conservation concern.

Arthropod vertical stratification in temperate deciduous forests: Implications for conservation-oriented management

“…Because tree bark inevitably becomes rougher and more epiphyte-laden with age ( Fig. 1A), old trees provide more canopy habitats than young trees (Elton, 1966;Fritz, 2009) and are no doubt of greater importance to bark dwelling arthropods.…”

“…In addition, epiphytic fungi or "sooty molds" often grow on leaves covered by honeydew excreted by sap-sucking insects. It has long been known that epiphytes are not distributed evenly in the canopies of these forests (Billings and Drew, 1938;Hale, 1952Hale, , 1965Elton, 1966;Stubbs, 1989;Fritz, 2009). In an old-growth Wisconsin forest, for example, Hale (1952) recorded epiphytes along the entire lengths of 10 wind-thrown trees belonging to seven species.…”

Fine spatial pattern of an epiphytic lichen species is affected by habitat conditions in two forest types in the Iberian Mediterranean region

“…We found that, the smooth bark of young beech trees made propagule attachment very difficult, whereas large colonized trees were located close to a focal tree. Thus, beech tree diameter is a key parameter, because bark becomes coarser with age and larger trees have been available for colonization for a longer time period (Barkman 1958;Sillett et al 2000;Gu et al 2001;Belinchón et al 2009;Fritz 2009). However, the characteristic rough bark of oak trees, even when young, seemed more suited to the establishment of L. pulmonaria.…”

Protective management of trees against debarking by deer negatively impacts bryophyte diversity

“…Ohdaigahara. This is because bryophytes contribute significantly to the species richness and biomass of tree trunks (Fritz 2009;Hale 1952;Lyons et al 2000), as well as for ecosystem functions such as rainfall interception and nutrient cycling (Coxson 1990;Nadkarni 1984;Pypker et al 2006a, b).…”