Effects of selection cutting on the abundance and fertility of indicator lichens Lobaria pulmonaria and Lobaria quercizans

Published source details Edman M., Eriksson A. & Villard M. (2008) Effects of selection cutting on the abundance and fertility of indicator lichens Lobaria pulmonaria and Lobaria quercizans. Journal of Applied Ecology, 45, 26-33.
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Summary

The effects of two contrasting silvicultural treatments designed in part for conservtion purposes, selection cutting and leaving uncut stands, on the abundance and fertility of two dominant species of epiphytic lichens, Lobaria pulmonaria and L. quercizans were investigated in a hardwood forest in New Brunswick, eastern Canada.

Study site: The study was conducted on land owned by Acadian Timber Income Fund, in north-western New Brunswick (47°10′N, 67°13′W). The dominant tree species was sugar maple Acer saccharum; 28 forest stands were selected representing i) selection cuts (felled during 1996-2000, i.e. 5-9 years old) and ii) ‘uncut’ stands subject only to low-intensity single-tree cutting at least 35 years previously.

Lichen sampling: From July to August 2005, within each stand along three 80 m transects (at least 120 m from forest edges), the abundance and fertility of the two study lichens (large foliose species that grow on the bark of deciduous trees, particularly maples Acer spp.) was quantified on 36 trees.

Forest structure: Forest structure was quantified by collecting data on selected variables along the transects in each stand. Species and d.b.h. were recorded for trees within 2 m either side of a transect. At the centre point and every 20 m along transects, canopy closure was estimated and sapling (>2 m high, ≤ 8 cm d.b.h.) density within a 2-m radius recorded; tree basal area was also estimated.

The abundance of L. quercizans and L. pulmonaria was four and five times higher, respectively, in uncut stands compared to selection cuts. Fertile lichens were also much less prevalent in the selection cuts: average numbers of maples hosting fertile L. pulmonaria was 10.4 in uncut stands and 0.4 in selection cuts; the average numbers of maples hosting fertile L. quercizans was 9.1 in uncut stands and 1.8 in selection cuts.

The most important predictive factors of lichen abundance at the stand level were total tree basal area (41% higher in uncut stands) and canopy closure (25% higher in uncut stands).

The fertility of both lichen species was strongly correlated with their abundance. These results suggest that studies ignoring lichen fertility may underestimate the negative effects of selective logging on lichens.

Note: The compilation and addition of this summary was funded by the Journal of Applied Ecology (BES). If using or referring to this published study, please read and quote the original paper, this can be viewed at: http://www3.interscience.wiley.com/cgi-bin/fulltext/119392024/PDFSTART