Terrestrial lichen response to partial cutting in lodgepole pine forests on caribou winter range in west-central British Columbia

Abstract

In west-central British Columbia, terrestrial lichens located in older, lodgepole pine (Pinus contorta) forests are important winter forage for woodland caribou (Rangifer tarandus caribou). Clearcut harvesting effectively removes winter forage habitat for decades, so management approaches based on partial cutting were designed to maintain continuous lichen-bearing habitat for caribou. This study tested a group selection system, based on removal of 33% of the forest every 80 years in small openings (15 m diameter), and two irregular shelterwood treatments (whole-tree and stem-only harvesting methods) where 50% of the stand area is cut every 70 years in 20 to 30 m diameter openings. The abundance of common terrestrial lichens among the partial cutting and no-harvest treatments was compared across five replicate blocks, pre-harvest (1995) and post-harvest (1998, 2000 and 2004). The initial loss of preferred forage lichens (Cladonia, Cladina, Cetraria and Stereocaulon) was similar among harvesting treatments, but there was greater reduction in these lichens in the openings than in the residual forest. After eight years, forage lichens in the group selection treatment recovered to preharvest amounts, while lichen in the shelterwood treatments steadily increased from 49 to 57% in 1998 to about 70% of pre-harvest amounts in 2004. Although not part of the randomized block design, there was substantially less lichen in three adjacent clearcut blocks than in the partial cuts. Regression analysis pre-and post-harvest indicated that increased cover of trees, shrubs, herbs, woody debris and logging slash corresponded with decreased forage lichen abundance. In the short-term, forestry activities that minimize inputs of woody debris, control herb and shrub development, and moderate the changes in light and temperatures associated with canopy removal will lessen the impact on lichen. Implementation of stand level prescriptions is only one aspect of caribou habitat management. A comprehensive approach should consider all factors and their interactions to maintain a viable population of woodland caribou in west-central British Columbia.

Can partial‐cut harvesting be used to manage terrestrial lichen habitat? A review of recent evidence

“…He observed that environmental conditions under piles and at pile edges were moderated, and appeared to provide suitable microenvironments for lichens, whereas lichens present in road-side delimbed sites without cover often appeared to be suffering damage from exposure. Waterhouse et al (2011) observed that slash on the ground and suspended low above the ground adversely affected lichens, but high suspended slash and areas adjacent to slash piles may provide refugia for lichens. An important point raised by Waterhouse et al (2011) was that whole-tree (WT) and stem-only (SO) harvesting systems have the potential of affecting lichens differently.…”

“…Waterhouse et al (2011) observed that slash on the ground and suspended low above the ground adversely affected lichens, but high suspended slash and areas adjacent to slash piles may provide refugia for lichens. An important point raised by Waterhouse et al (2011) was that whole-tree (WT) and stem-only (SO) harvesting systems have the potential of affecting lichens differently. Whole tree skidding is likely to cause more damage to the lichen mat than skidding of delimbed stems, and results in roadside processing areas that are severely disturbed.…”

“…In the northeastern portion of the Itcha-Ilgachuz range, mean lichen cover declined from 20.5% on plots established in 2005 and 2006 to 16.4% in 2008 (Cichowski et al, 2009). In the western portion of the Itcha-Ilgachuz, terrestrial lichen cover in the no-harvest controls for the silvicultural systems study of Waterhouse et al (2011) declined from the 2004 pre-mountain pine beetle cover of 11.3% to 9.7% in 2008, but this change was not statistically significant (Waterhouse, 2011). At Kennedy Siding, terrestrial lichen cover was 24% in 2006, 17% in 2007, and 12% in 2008(Cichowski, 2011.…”

“…A separate examination of trends between 2005 and 2007 indicated that changes in light transmission or interception had a significant effect on changes in lichen abundance, suggesting that by seven to eight years after the initial attack, increased light was beginning to create favourable conditions for lichen recovery (Cichowski et al, 2009). Armleder and Waterhouse (2008) and Waterhouse et al (2011) have asserted that lichen morphotypes that have been growing in subdued light are adversely affected by a sudden increase in exposure to light. Lichens of the same species growing under different light conditions exhibit both morphological and physiological differences.…”

Variability and patterns in forest soil and vegetation characteristics after prescribed burning in clear-cuts and restoration burnings

“…Biomass and cover of dwarf-shrubs and most mosses decrease due to disturbance, while lichens, forbs and graminoids are often regenerating abundantly in sites disturbed by fire and/or clearcutting (Fig. 3;Foster 1985;Shevtsova et al 1995;Schimmel and Granström 1996;NguyenXuan et al 2000;Parlane et al 2006;Waterhouse et al 2011;Turtiainen et al 2013;Johnson et. al.…”