Lichen Biomass Research Articles

Vertical distribution and nitrogen content of epiphytic macrolichen functional groups in sub-boreal forests of central British Columbia

Vertical distribution, biomass abundance and nitrogen stocks of epiphytic macrolichens were examined in the two dominant tree species, interior hybrid spruce (Picea engelmannii Parry ex Engelm. x glauca (Moench) and subalpine fir (Abies lasiocarpa (Hook.) Nutt.), in sub-boreal spruce forest ecosystems of central British Columbia. Lichens were contrasted between two different site types containing either high (High Cyano) or low (Low Cyano) epiphytic cyanolichen abundance. A single rope technique was used for canopy access and a ‘clump’ method was used to estimate the abundance of arboreal lichens at different heights within both canopy tree species for five functional groups: Bryoria spp., Alectoria sarmentosa, foliose chlorolichens, bipartite cyanolichens, and Lobaria pulmonaria (the only tripartite cyanolichen). In this way, the relationship between average lichen biomasses and tree height for each tree species were assessed. We determined that biomass was dependent on tree height and species, with a greater abundance of lichen appearing on fir trees (mean±SD; 1588±428gtree−1) than the generally taller spruce trees (917±422gtree−1). Foliose chlorolichen biomass was more abundant in trees with low abundance of L. pulmonaria (777.1±365.9gtree−1) than those with a high abundance of L. pulmonaria (553.6±400gtree−1). Much of this increase in chlorolichen biomass in trees with low cyanolichen abundance was a result of greater chlorolichen abundances in lower canopy positions where cyanolichens would otherwise predominate. Although bipartite cyanolichens had a higher %N (∼3.2%N) than L. pulmonaria (2.3%N) of dry mass, there was a much higher abundance of L. pulmonaria in the canopy of High Cyano sites containing a larger amount of N (4.04±0.95kgNha−1) than in all bipartite cyanolichens combined (2.33±1.11kgNha−1) or any other lichen spp. Chlorolichens are poor competitors for lower branch positions when cyanolichens such as L. pulmonaria are abundant, the latter of potential importance for N inputs into N-limited sub-boreal forests of central BC.

Biosorption properties of zinc(II) from aqueous solutions by Pseudevernia furfuracea (L.) Zopf

Pseudevernia furfuracea (L.) Zopf biosorption efficiency for zinc(II) was determined. The biosorption efficiency of Zn(II) onto P. furfuracea was significantly affected by the parameters of pH, biomass concentration, stirring speed, contact time, and temperature. The maximum biosorption efficiency of P. furfuracea was 92% at 10 mg/L Zn(II), for 5 g/L lichen biomass dosage. The biosorption of Zn(II) ions onto biomass was better described by the Langmuir model and the pseudo-second-order kinetic. The obtained thermodynamic parameters from biosorption of Zn(II) ions onto biomass were feasible, exothermic, and spontaneous. The different desorbents were used to perform the desorption studies for Zn(II)-loaded biomass. Fourier transform infrared (FTIR) spectroscopy was used to determine the participating functional groups of P. furfuracea biomass in Zn (II) biosorption. The broad and strong bands at 3292–3304 cm−1 were due to bound hydroxyl (–OH) or amine (–NH) groups. The effective desorptions were obtained up to 96% with HNO3. P. furfuracea is an encouraging biosorbent for Zn(II) ions, with high metal biosorption and desorption capacities, availability, and low cost. It was believed that by using this new method in which biomass is used as a sorbent, the toxic pollutants could be selectively removed from aqueous solutions to desired low levels. The remarkable properties of lichens in the transformation and detoxification of organic and inorganic pollutants are well known, and many processes have received attention in the general area of environmental biotechnology and microbiology.Implications:The remarkable properties of lichens in the biosorption capacity of organic and inorganic pollutants are well known, and many processes have received attention in the general area of environmental biotechnology and microbiology.

Effects of reindeer grazing and forestry on ground lichens in Finnish Lapland

Reindeer husbandry and forestry are practiced in the same areas in northern Fennoscandia. Reindeer pastures have largely deteriorated. We aimed to quantify the separate and combined effects of reindeer grazing and forestry on the amount of ground lichens. To do this, we mapped and inventoried all larger enclosures (49) in Finnish Lapland where forest management practices were similar in both sides of the fence. The average time since fencing was 43 years. We recorded the cover and estimated dry biomass of ground lichens, as well as parameters describing forest stand characteristics. The effect of reindeer grazing on both the cover and estimated dry biomass of lichens was clear: in the ungrazed (fenced) sites, the lichen cover (35.8%) was on average 5.3-fold and the dry biomass (1929 kg ha) 14.8-fold compared with the corresponding estimates in the grazed sites (6.8% and 130 kg ha). The effect of forestry on lichens was smaller. In the grazed stands the cover and biomass of lichens were higher in the mature stands compared to the younger stand development classes, whereas in the ungrazed stands there were no significant differences between the development classes. Both reindeer grazing and forestry affect the cover and biomass of ground lichens. The influence of reindeer grazing is, however, much heavier than that of forestry. The decrease of not only the biomass, but also the lichen cover, is alarming. The decrease of lichen cover may hinder the recovery of reindeer pastures, which in the long run endangers the sustainability of reindeer husbandry.–1–1

Erratum to: Both reindeer management and several other land use factors explain the reduction in ground lichens (Cladonia spp.) in pastures grazed by semi-domesticated reindeer in Finland

Roles of intensive reindeer grazing and several additional land use factors in the reduction in ground lichens (Cladonia spp.) in pastures grazed by the semi-domesticated reindeer have been argued in Finland. Our analysis showed that several factors and processes explain the standing biomass of lichens (during 2005–2008) and the recent changes in this biomass (after 1995–1996) on lichen pastures located in the 20 northernmost herding districts in Finland. The higher the long-term reindeer densities on the lichen pastures the lower was the lichen biomass. The lichen biomass was also strongly affected by the grazing system; the lowest biomass values of lichens were measured in all grazing areas that were used in the snow-free seasons. The lichen biomass in pine forests less than 80 years old and in all mountain type lichen pastures was lower than that in mature and old pine forests. The lichen biomass also decreased as the proportion of arboreal lichen pastures within a district decreased and the proportion of human infrastructure increased. The aerial drift of heavy metals from the Kola Peninsula appeared to reduce lichens in a small north-eastern part of the study area. Increases in summer precipitation and winter temperatures increased the amount of lichens, but increases in summer temperatures and winter precipitation had the opposite effect. Reindeer densities, grazing system, pasture type and the previous abiotic factors were also associated with the reduction in lichen biomass between the inventories. We conclude that several local, regional and even global factors and processes affect the state of reindeer pastures in large and complex grazing ecosystems. Therefore, more comprehensive research and management strategies for the entire reindeer herding environment are needed.

Variable retention management influences biomass of Misodendrum and Usnea in Nothofagus pumilio southern Patagonian forests

Variable retention systems (retention of some existing trees in different densities along with significant elements of the original forest after logging) aim to mitigate the impact of harvesting in native temperate forests, improving biodiversity conservation in managed stands. This study evaluates the effect of variable retention harvesting on epiphytic lichens (Usnea barbata) and mistletoes (Misodendrum punctulatum) in Nothofagus pumilio forests. The abundance of these canopy-dwelling species can be estimated by measuring their litter fall. We quantified mistletoe, lichen and tree litter fall monthly for 3 years. Tree and lichen biomasses were influenced by canopy cover, being higher in primary forests than in harvested stands. However, aggregated retention showed the highest mistletoe biomass production. Furthermore, mistletoe biomass increased while lichen biomass decreased over the years after harvesting. Variable retention was useful in maintaining both lichen and mistletoe biomass after harvest, but aggregates were not enough to maintain the original level of lichen populations. Forest harvesting with variable retention generates positive (litter input) and negative (decline of host growth) effects of mistletoes and epiphytic lichens at community level, which should be evaluated during conservation and management planning.

Evaluation of different isotherm models, kinetic, thermodynamic, and copper biosorption efficiency of Lobaria pulmonaria (L.) Hoffm.

The biosorption characteristics of Cu(II) ions from aqueous solution using Lobaria pulmonaria (L.) Hoffm. biomass were investigated. The biosorption efficiency of Cu(II) onto biomass was significantly influenced by the operating parameters. The maximum biosorption efficiency of L. pulmonaria was 65.3% at 10 mg/L initial metal concentration for 5 g/L lichen biomass dosage. The biosorption of Cu(II) ions onto biomass fits the Langmuir isotherm model and the pseudo-second-order kinetic model well. The thermodynamic parameters indicate the feasibility and exothermic and spontaneous nature of the biosorption. The effective desorption achieved with HCl was 96%. Information on the nature of possible interactions between the functional groups of the L. pulmonaria biomass and Cu(II) ions was obtained via Fourier transform infrared (FTIR) spectroscopy. The results indicated that the carboxyl (–COOH) and hydroxyl (–OH) groups of the biomass were mainly involved in the biosorption of Cu(II) onto L. pulmonaria biomass. The L. pulmonaria is a promising biosorbent for Cu(II) ions because of its availability, low cost, and high metal biosorption and desorption capacities. Implications: Lobaria pulmonaria is a promising biosorbent for Cu(II) ions because of its availability, low cost, and high metal biosorption and desorption capacities. To the best of our knowledge, this is the first paper on the biosorption Cu by L. pulmonaria.

Lichen Conservation in Heavily Managed Boreal Forests

Lichens are an important component of the boreal forest, where they are long lived, tend to accumulate in older stands, and are a major food source for the threatened woodland caribou (Rangifer tarandus caribou). To be fully sustainable, silvicultural practices in the boreal forest must include the conservation of ecological integrity. Dominant forest management practices, however, have short-term negative effects on lichen diversity, particularly the application of herbicides. To better understand the long-term effects of forest management, we examined lichen regeneration in 35 mixed black spruce (Picea mariana) and jack pine (Pinus banksiana) forest stands across northern Ontario to determine recovery following logging and postharvest silvicultural practices. Our forest stands were 25-40 years old and had undergone 3 common sivilcultural treatments that included harvested and planted; harvested, planted, and treated with N-[phosphonomethyl] glycine (glyphosate); and harvested, planted, and treated with 2,4-dichlorophenoxyacetic acid (2,4-D). Forest stands with herbicide treatments had lower lichen biomass and higher beta and gamma diversity than planted stands that were not treated chemically or control stands. In northwestern Ontario, planted stands that were not treated chemically had significantly greater (p < 0.05) alpha diversity than stands treated with herbicides or control stands. Our results show that common silvicultural practices do not emulate natural disturbances caused by wildfires in the boreal forest for the lichen community. We suggest a reduction in the amount of chemical application be considered in areas where lichen biomass is likely to be high and where the recovery of woodland caribou is an objective.

The influence of fire history on selection of foraging sites by barren-ground caribou

We used an information-theoretic model comparison approach to investigate the influence of forest stand attributes resulting from wildfire on the occupancy of winter habitats by barren-ground caribou (Rangifer tarandus groenlandicus) in the Northwest Territories, Canada. We used field data describing forest stand and understory attributes to develop multinomial regression models. These analyses identified a combination of ground cover type and tree volume (i.e., stand basal area) as best able to describe the observed selection of feeding sites. An observed increase in the percent ground cover of lichen had a positive influence on site selection, while an increase in the percent rock cover and basal area of conifer trees had a negative influence on selection of feeding sites by caribou. The most parsimonious regression model predicted site use with an accuracy of 87%. Lastly, we used published equations to determine the biomass of fruticose lichens on experimental and control sites classified as unburned. Our data indicated that fruticose lichen biomass on the winter range of the Bathurst herd of barren-ground caribou was high compared to winter habitats of caribou in Alaska and the Yukon Territory, and falls in the general range of lichen values reported for winter habitats of the more easterly Beverly herd, as well as portions of Saskatchewan, Manitoba, and Ungava. Overall, the analyses of feeding-site selection suggest that Bathurst caribou forage in areas with a high percentage cover and biomass of lichen, and that future increased incidence and severity of forest fires could cause a temporary decrease in the quality of winter habitat available to the Bathurst herd.

Usnea lichen community biomass estimation on volcanic mesas, James Ross Island, Antarctica

Ground macrolichens dominated by several species of fruticose Usnea spp. with foliose Leptogium puberulum constitute an important component of the terrestrial ecosystem of James Ross Island. Long-term monitoring of lichen communities in respect to their reaction to ongoing climatic changes in this part of Antarctica became a research task for scientists in recent years. The non-destructive estimation of lichen biomass provides data necessary for the management and protection of Antarctica. We have developed and tested the methodology of non-destructive estimation of biomass of fruticose Usnea species, which predominate in the ice-free tertiary basalt outcrop areas on James Ross Island. In 38 experimental squares (non-destructive measurements), the density and height of lichen thalli were measured and digital photography with ground cover evaluation was performed. Lichen biomass was harvested from 14 experimental squares and analysed for dry mass, chlorophyll a, b content, and thalli surface area (TSA). Predictive linear models were constructed from available non-destructively measured variables with the aim to maximize predictive accuracy for the destructively measured attributes. A total of 82.3 % of variability in the TSA values was explained (87.5 % for biomass determination). Cross-validated prediction error for lichen TSA estimation was 423 cm2 (11.5 % of the average TSA). In the case of lichen dry mass determination, cross-validated prediction error was 4.53 g m−2 (7.3 % of the average dry mass). This study proves that macrolichens in maritime Antarctica can be monitored non-destructively by simple field methods combining digital photography and measurements of lichen thalli in botanical squares.

Features of the biomass distribution of epiphytic lichens on scotch pine (Lower Angara Region)

The biomass of epiphytic lichens growing on Scots pine varies from 130 to 1090 g and is composed mainly of lichens from three genera: Bryoria (45%), Hypogymnia (34%), and Evernia (12%). The majority of lichens (66%) grow on tree branches (96%) in the zone of maximum development, located at a height of 9–13.5 m. The lichen biomass on tree trunks is insignificant (4%) and located mainly at their bottom part (70%).

Biosorption of Pb(II) by Nonliving Lichen Biomass of Cladonia rangiformis Hoffm

Environmental contamination by toxic metals is a serious problem due to their extreme toxicity towards aquatic life and humans. Biosorption is an alternative technology to conventional processes for the removal of metals. Biosorption of Pb(II) ions on the lichen biomass of Cladonia rangiformis Hoffm. is presented in this research. Batch experiments were conducted to study the biosorption properties of lichen biomass for Pb(II) and the effects of initial metal ion concentration, initial pH, biosorbent concentration, stirring speed and contact time on biosorption efficiency. The optimum pH value was found out 5.0 which was the native pH value of solution. Concentrations ranging from 30 to 150 mg/L Pb(II) were studied and the biosorptive removal efficiency of the metal ions was obtained as 99.5%. The experimental biosorption data were fitted to the Freundlich adsorption model and the regression constants were determined at 15oC. The results indicated that the biomass of Cladonia rangiformis is a suitable biosorbent for removing Pb(II) from aqueous solutions.

High belowground biomass allocation in an upland black spruce (Picea mariana) stand in interior Alaska

The root system of forest trees account for a significant proportion of the total forest biomass. However, data is particularly limited for forests in permafrost regions. In this study, therefore, we estimated the above- and belowground biomass of a black spruce (Picea mariana) stand underlain with permafrost in interior Alaska. Allometric equations were established using 4–6 sample trees to estimate the biomass of the aboveground parts and the coarse roots (roots >5 mm in diameter) of P. mariana trees. The aboveground biomass of understory plants and the fine-root biomass were estimated by destructive sampling. The aboveground and coarse-root biomasses of the P. mariana trees were estimated to be 3.97 and 2.31 kg m−2, respectively. The aboveground biomass of understory vascular plants such as Ledum groenlandicum and the biomass of forest floor mosses and lichens were 0.10 and 0.62 kg m−2, respectively. The biomass of fine roots <5 mm in diameter was 1.27 kg m−2. Thus, the above- and belowground biomasses of vascular plants in the P. mariana stand were estimated to be 4.07 and 3.58 kg m−2, respectively, indicating that belowground biomass accounted for 47% of the total biomass of vascular plants. Fine-root biomass was 36% of the total root biomass, of which 90% was accumulated in the surface organic layer. Thus, this P. mariana stand can be characterized as having extremely high belowground biomass allocation, which would make it possible to grow on permafrost with limited soil resource availability.

Detecting changes in the state of reindeer pastures in northernmost Finland, 1995–2005.

ABSTRACTThe state of pastures in the Finnish reindeer management area has been monitored since 1995 using remote sensing and field inventory. The first inventory was made in 1995–1996, updated in the beginning of 2000s and repeated in 2005–2008. By comparing results from 1995–1996 and 2005–2008 we can observe clear changes in forest cover, structure and ground lichen abundance. To evaluate pasture/vegetation changes on the basis of separate classifications we have used a grid approach. By implementing a 500 by 500 m grid network and summarizing pasture classes for every grid cell we can visualize and quantify intensity of change. By comparing 1995–1996 and 2005–2008 we can see a clear decrease in the number of cells classified old growth dominated forest, and also an increase of fragmentation can be detected. With a 7.5 ha threshold the amount of old growth forest was reduced by 5%, for 20 ha the decrease was 21%. This indicates a significant change in forest landscape structure, fragmentation and reduction of reindeer winter pasture value in large areas. Pixel wise comparison showed no substantial changes in pasture areas. There is a degree of uncertainty in change detection; changes in remote sensing instrument, changes in processing software and methodology, changes in field methods and ancillary data, and obviously also bias introduced by differences between analysts. When comparing reindeer lichen biomass between 1995–1996 and 2005–2008 on the basis of field site data, the measured lichen biomass has declined in 19 out of the 20 reindeer management districts. Only one district showed slight improvement, in three districts there was a notable drop in lichen biomass, from over 1500 kg/ha to about 500 kg/ha. Also amount of arboreal lichens declined due to felling of old growth forest, confirming the findings on the grid cell level. Consequently grass, shrub and sapling stands increased as felled areas start to grow graminoids and herbs.

Current state of forage resources and feeding of reindeer (Rangifer tarandus) and musk oxen (Ovibos moschatus) in the arctic tundras of Wrangel Island

The species composition and aboveground biomass of plant and lichens and the composition of reindeer and musk ox diet in the arctic tundra of Wrangel Island were studied in 2004 to 2007. The above-ground phytomass in different areas of the island varied from 1105 to 2100 kg/ha. The composition of plants consumed by reindeer and musk oxen and their proportions in the diet were determined by standard micro-histological analysis of plant remains in their feces. The results showed that, either in winter or in summer, both species obviously preferred feeding on willows (Salicaceae), which comprised almost half of their diet. Moreover, their feeding was highly selective, especially with respect to sedges and rushes (Cyperaceae + Juncaceae) and legumes (Fabaceae). Although the contributions of these plant groups to the total aboveground phytomass were very small (less than 4 and 8%), their proportions in the diet reached 27 and 24%, respectively. Mosses were not a preferred forage: their proportion in the aboveground phytomass reached 40%, but that in the diets of both species was below 10% in summer and increased to 20% only in the winter diet of reindeer. At a high abundance of lichens (up to 20% of the aboveground phytomass), neither of the animals consumed them during the study period.

Rapid recovery of recently overexploited winter grazing pastures for reindeer in northern Norway

Abstract During the last 25 yr, Sami reindeer husbandry in parts of Finnmarksvidda in the Norwegian Arctic has been in a critical state because of overexploitation of lichen-dominated tundra, which serves as winter forage. To better understand the ecosystem’s capabilities for recovery we investigated vegetation cover changes over a 7-yr period, starting in 1998, at 52 sites dispersed over a large area at Finnmarksvidda. Two types of plots were established: one fenced from reindeer grazing and trampling and one open for reindeer. The investigations in 2005 showed that lichen cover had had a significant and rapid increase (up to 8.6-fold per year). The cover of vascular plants, mainly dwarf shrubs, also increased significantly, while barren areas and the cover of litter decreased significantly during the period. Mean relative growth rate of lichen biomass was 0.083 ± 0.011 per year in open plots, which is considered very rapid recovery compared to previous studies. Lichen recovery was significantly faster on leeward ridges than on exposed ridges, and fencing alone did not have any significant effects on lichen recovery, but in interaction with time, fencing contributed to increasing recovery rates. The lichen heath recovery was reciprocally correlated with reindeer density. In addition, lichen recovery was probably facilitated by recent climate changes, viz. shallower snow depths which made leeward tundra and forest floor vegetation accessible for reindeer, and increased summer precipitation rates which improved growth rates. The results from this study show that in a very short time there was a transition from an overexploited depauperate vegetation and barren ground state to a flourishing lichen-dominated vegetation state, suggesting that the injuries were repairable. The vegetation transitions which have taken place in the study area are considered to be reversible with fewer persistent effects.

Estimating the biomass of woodland caribou forage lichens

Lichens are an important winter food source for woodland caribou ( Rangifer tarandus caribou ), but quantifying their abundance is difficult. Here, we present an efficient method for assessing lichen biomass at the stand level in boreal forests. We measured lichens occurring in high enough abundance to serve as a winter food source for woodland caribou in 51 boreal forest stands. Samples of each species or genus were collected from each stand and a mean abundance (cover) to biomass ratio was established. The method does not require samples to be collected or weighed, due to this predetermined relationship, and it also accounts for the variation in biomass among lichen species that are equally abundant. The variation in lichen growth between stands was assessed by means of five lichen abundance classes. The proposed method was tested in 34 stands with a wide range of ages and stem densities. The average time to complete a lichen biomass assessment was approximately 2 h. This method is an efficient and accurate tool that can assist forest managers and researchers with ecological studies on lichens or with monitoring changes in lichen biomass over time and with habitat assessments for organisms for which lichens are important, such as woodland caribou.

Contrasting sensitivity to extreme winter warming events of dominant sub‐Arctic heathland bryophyte and lichen species

Summary1. Climate change in northern high latitudes is predicted to be greater in winter rather than summer, yet little is known about the effects of winter climate change on northern ecosystems. Among the unknowns are the effects of an increasing frequency of acute, short‐lasting winter warming events. Such events can damage higher plants exposed to warm, then returning cold, temperatures after snow melt, and it is not known how bryophytes and lichens, which are of considerable ecological importance in high‐latitude ecosystems, are affected by such warming events. However, even physiological adaptations of these cryptogams to winter environments in general are poorly understood.2. Here we describe findings from a novel field experiment that uses heating from infrared lamps and soil warming cables to simulate acute mid‐winter warming events in a sub‐Arctic heath. In particular, we report the growing season responses of the dominant lichen, Peltigera aphthosa, and bryophyte, Hylocomium splendens, to warming events in three consecutive winters.3. While summertime photosynthetic performance of P. aphthosa was unaffected by the winter warming treatments, H. splendens showed significant reductions in net photosynthetic rates and growth rates (of up to 48% and 52%, respectively). Negative effects were evident already during the summer following the first winter warming event.4. While the lichen develops without going through critical phenological stages during which vulnerable organs are produced, the moss has a seasonal rhythm, which includes initiation of growth of young, freeze‐susceptible shoot apices in the early growing season; these might be damaged by breaking of dormancy during warm winter events.5. Synthesis. Different sensitivities of the bryophyte and lichen species were unexpected, and illustrate that very little is known about the winter ecology of bryophytes and lichens from cold biomes in general. In sharp contrast to summer warming experiments that show increased vascular plant biomass and reduced lichen biomass, these results demonstrate that acute climate events in mid‐winter may be readily tolerated by lichens, in contrast to previously observed sensitivity of co‐occurring dwarf shrubs, suggesting winter climate change may compensate for (or even reverse) predicted lichen declines resulting from summer warming.

Biomass, diversity and composition of epiphytic macrolichens in primary and secondary forests in the subtropical Ailao Mountains, SW China

Epiphytic macrolichen litterfall was collected over 3 years from primary evergreen broad-leaved forests (PF), Populus bonatii secondary forests (PBSF), middle-aged oak secondary forests (MOSF) and old-aged oak secondary forests (OOSF) of the Ailao Mountains in SW China. To assess changes in the epiphyte communities of the subtropical forests, we compared the differences in biomass, species diversity and community structure of epiphytic lichens from the four forest types. A total of 51 species were recorded in this study. Species richness was highest in the PF, while α-diversity was highest in the MOSF. Lichen biomass differed markedly across the four forest types and was highest in the MOSF. The contribution of each dominant species to total biomass, except Nephromopsis ornata, was significantly different among forest types. Moreover, the percent contribution of foliose chlorolichens to litterfall tended to be higher in later-succession forest types, whereas the contributions of cyanolichens and fruticose chlorolichens were lower in these forest types. Compared to the PF, the lichen community structure in secondary forests differed significantly, implying that at least a few hundred years were needed for the restoration of these lichen communities. In particular, nineteen lichens were suggested as indicators, and eleven of them were present in the MOSF. Canonical correspondence analysis (CCA) indicated that the observed differences were mainly attributed to canopy openness and the size of the largest tree, which represented an environmental gradient from exposed to sheltered habitats. The diversity of host tree species was also important in determining the composition and distribution of macrolichens. Our findings support the idea that the maintenance of the forest landscape mosaic of heterogeneous forest types may be an important management practice to maintain or promote the epiphytic lichen community of the subtropical Ailao Mountains.

Assessing terrestrial lichen biomass using ecoforest maps: a suitable approach to plan conservation areas for forest-dwelling caribou

Terrestrial lichens are an important part of the winter diet of forest-dwelling caribou ( Rangifer tarandus caribou (Gmelin, 1788)), and developing forest management guidelines to support high lichen biomass could enhance both individual- and population-level health of this threatened species. Our objective was to develop an index to assess terrestrial lichen biomass available to caribou at the landscape scale using ecoforest maps based on forest characteristics (age, density, and height) and geographical variables (slope, altitude, and latitude). We sampled 439 sites within 8340 km2 of the spruce–moss domain located &gt;100 km north of the Saguenay River (Quebec, Canada). Since they are known to support terrestrial lichen, we sampled only spruce-dominated stands older than 50 years, representing 41.8% of the study area. Using a two-step approach, we first modeled lichen occurrence and thereafter lichen biomass in sites where lichens were found. Lichen occurrence was positively correlated with latitude but negatively with stand age, height, and density. Lichen biomass was primarily a function of altitude and tree density. Using this index could prioritize conservation of areas that are most likely to contain high lichen biomass, thus favoring caribou population maintenance in logged landscapes.

Fire, grazing history, lichen abundance, and winter distribution of caribou in Alaska's taiga

AbstractIn the early 1990s the Nelchina Caribou (Rangifer tarandus) Herd (NCH) began a dramatic shift to its current winter range, migrating at least an additional 100 km beyond its historic range. We evaluated the impacts of fire and grazing history on lichen abundance and subsequent use and distribution by the NCH. Historic (prior to 1990) and current (2002) winter ranges of the NCH had similar vascular vegetation, lichen cover (P = 0.491), and fire histories (P = 0.535), but the former range had significantly less forage lichen biomass as a result of grazing by caribou. Biomass of forage lichens was twice as great overall (P = 0.031) and 4 times greater in caribou selected sites on the current range than in the historic range, greatly increasing availability to caribou. Caribou on the current range selected for stands with &gt;20% lichen cover (P &lt; 0.001), greater than 1,250 kg/ha (P &lt; 0.001) forage lichen biomass and stands older than 80 yr postfire (P &lt; 0.001). After fires, forage lichen cover and biomass seldom recovered sufficiently to attract caribou grazing until after ≥60 yr, and, as a group, primary forage lichen species did not reach maximum abundance until 180 yr postfire. Recovery following overgrazing can occur much more quickly because lichen cover, albeit mostly fragments, and organic substrates remain present. Our results provide benchmarks for wildlife managers assessing condition of caribou winter range and predicting effects of fires on lichen abundance and caribou distribution. Of our measurements of cover and biomass by species, densities and heights of trees, elevation, slope and aspect, only percentage cover by Cladonia amaurocraea, Cladina rangiferina, Flavocetraria cuculata, and lowbush cranberry (Vaccinium vitis‐idaea) were necessary for predicting caribou use of winter range. © 2011 The Wildlife Society