Manganese as a site factor for epiphytic lichens

Abstract

Decreasing abundance of epiphytic lichens with increasing Mn supply from the substratum or from stemflow was found in several coniferous forests of Europe (Germany) as well as western (Montana, British Columbia) and eastern North America (New York State). Experiments carried out with Hypogymnia physodes and other species of chloro- and cyano-lichens suggest that these correlations are causal. High Mn concentrations e.g. reduce chlorophyll concentrations, chlorophyll fluorescence and degrade the chloroplast in lichen photobionts. Excess Mn inhibits the growth of soredia of H. physodes and causes damage in the fine- and ultra-structure of the soredia. Adult lichen thalli remain structurally unaffected by Mn. Manganese uptake does not result in membrane damage. Calcium, Mg, Fe and perhaps also Si alleviate Mn toxicity symptoms in H. physodes. Lecanora conizaeoides is not sensitive to Mn in laboratory experiments or in the field. The data suggest that high Mn concentrations are an important site factor for epiphytic lichens in coniferous forests that until recently has been overlooked. Manganese reaching the microhabitat of epiphytic lichens is primarily soil-borne and is usually not derived from pollution.

Interactions of lichens with heavy metals

“…Mikhailova (2007) found that Cu pollution caused growth abnormalities, distortion of apothecia and colour changes in thalli of Tuckermanopsis sepincola and decreased production of soredia in Hypogymnia physodes. Excess Mn caused ultrastructural damage and inhibited soredial growth in Hypogymnia physodes (Hauck and Paul 2005).…”

Epiphytic lichen diversity and its dependence on bark chemistry in the northern Mongolian dark taiga

“…A largely natural chemical site factor that has been figured out to be significant for epiphytic lichens in the recent past is the local Mn supply (Hauck and Paul, 2005). Trees deposit surplus amounts of Mn in the bark (Fink, 1999;Schmull and Hauck, 2003), after the metal has been taken up from the soil.…”

Effects of manganese on chlorophyll fluorescence in epiphytic cyano- and chlorolichens

“…Combination of field studies and experimental work showed that epiphytic chlorolichen abundance in coniferous forests of Europe and North America is, among other factors, controlled by the supply with Mn (Hauck, 2003;Hauck and Paul, 2005). Cover of many lichen species decreased with increasing Mn concentration in bark (Hauck et al, 2001;Schmull and Hauck, 2003) or stemflow (Hauck et al, 2002a;Schmull et al, 2002).…”