Lichen Biomass Research Articles

СОВЕРШЕНСТВОВАНИЕ СПОСОБА ПОЛУЧЕНИЯ УСНИНОВОЙ КИСЛОТЫ ИЗ РАСТИТЕЛЬНОГО СЫРЬЯ ИСЛАНДСКОГО МХА

Relevance. Contemporary pharmaceutical industry requires constant search and development of new technologies for the production of pharmacological products. At the same time, the processing of plants, which contain substances with a therapeutic effect, is a promising direction. Their use in terms of economic and therapeutic effectiveness is sometimes very beneficial. It has been proven that lichen plants contain substances that have a therapeutic effect. Organisms of the genus Cladonia, which synthesize usnic acid, among them have a special significance and application. The extraction of usnic acid from lichen biomass is carried out using various organic solvents. At the same time, it is preferable to use techniques with the lowest cost with a high quantitative yield of extractives. In addition, extracts containing bioactive substances should exhibit significant biological activity. The aim is improving the technology of extraction of usnic acid from the vegetable raw materials of Cladonia rangiferina Hoff by determining the optimal components for its extraction. Materials and methods. The material for the study is raw material of Yagel (Deer Moss)/Cladonia rangiferina Hoff. The extractive properties of the most commonly used solvents (purified water, ethyl alcohol 40, 70 and 95%) were studied, among which the most effective was identified. The content of extractive substances was determined by the gravimetric analysis method. The results of the study. According to the results of a series of experiments to study extractive capabilities, of all solvents, the maximum extractive ability of extractive substances from Cladonia rangiferina Hoff was noted for 95% ethyl alcohol (7.38%). Ethyl alcohol 70% was produced with a high extraction capacity, however, it turned out to be less effective. The conclusion was made about these methods can be used to detect biologically active substances obtained from the raw materials of Cladonia rangiferina Hoff. The obtained developments create prerequisites for the development of regulatory documentation on the procedure and position of the relevant standard or a temporary pharmacopoeia article.

Himalayan lichen biomass for green synthesis of silver nanocolloids: growth kinetics, effect of pH and metal sensing.

Lichen is one of the most abundant non-vascular biomasses; however, a systematic study on the application of biomass in nanomaterial synthesis is very limited. In this study, an aqueous lichen extract was obtained from Hypotrachyna cirrhata, one of the most abundant Himalayan lichen biomasses, using a simple cold percolation method. The effects of extract-to-silver nitrate mixing ratio, pH and waiting time on the growth and stability of nanoparticles were systematically explored. The rate constant for bio-reduction was found to be 5.3 × 10-3 min-1. Transmission electron microscopy showed a narrow particle size distribution with a mean particle size of 11.1 ± 3.6 nm (n = 200). The X-ray diffraction and selected area electron diffraction techniques confirmed the formation of cubic crystals. The synthesized colloidal solution showed excellent response to Hg2+ and Cu2+ ions in spiked water samples. The limit of detection and calibration sensitivity for Hg2+ and Cu2+ ions were found to be 1 and 5 mg l-1 and 2.9 × 10-3 and 1.6 × 10-3 units ppm-1, respectively. These findings suggested that spherical silver nanoparticles with a narrow particle size distribution can be synthesized on a laboratory scale using an aqueous H. cirrhata lichen extract, and the colloidal solution can be used for the detection of selected heavy metals in water samples.

Multi-isotope analysis of bone collagen of Late Pleistocene ungulates reveals niche partitioning and behavioural plasticity of reindeer during MIS 3

Here we present stable carbon, nitrogen and sulfur isotope ratios of collagen extracted from Rangifer, Equus and Bison bone (n = 128) from different stratigraphic levels at the chronologically well-constrained Middle and Upper Palaeolithic site of Les Cottés, France. Samples were taken from five phases of site use (US08, US06, US04 [upper and lower], and US02; ~ 45.8–35.3 ka cal BP) to explore the dietary and spatial palaeoecology of these ungulate species during MIS 3, and the contemporary climate. Temporal trends in δ15N values of all species broadly align with other climatic indicators at the site and the lowest values in US04 correspond to the Heinrich 4 cooling event, reflecting changes in the composition of soil/plant nitrogen at this time. Rangifer collagen is 13C-enriched compared to the other species throughout, consistent with lichen consumption. However, this isotopic niche partitioning between Rangifer and Equus/Bison is most extensive during US04, indicating plasticity in reindeer feeding behaviour, and potentially overall increased lichen biomass during this cooler/more arid phase. Rangifer δ34S values are consistently lower than Equus and Bison, which could be indicative of their more extensive spatial ranges incorporating greater inland areas. Equus and Bison demonstrate a significant decrease in δ34S values through time, which may be linked to contemporary climatic decline.

Cryptogamic Biomass in Pannonic Acidic Sand Steppes Subject to Changing Land-Use.

Cryptogams, often neglected in vegetation dynamics studies, compose a large part of biomass and contribute to the biodiversity of sandy grasslands. Since the work of Verseghy (1970s), their productivity has not been analyzed in Hungary. We studied the lichen and bryophyte dynamics (hereinafter called cryptogams) at two Eastern Hungarian dry sandy grassland sites. The sites of Corynephorus canescens and of Festuca vaginata dominance, respectively, belonging to the community Festuco vaginatae-Corynephoretum have been monitored. We aimed at (1) quantifying the diversity and biomass of the cryptogamic communities; (2) exploring the cryptogamic response to management changes; and (3) studying the effect of experimental management (fencing) on the cryptogamic assemblages. The sites have been compared in 2013 and 2018, respectively. Forty microplots per site per management have been analyzed in both years. Samples of lichens and bryophytes were hand-sorted, dried and then measured. Fencing has led to increased biomass of cryptogams within a few years. Lichens in general benefited comparatively more from exclosure than bryophytes. The increase in lichen biomass (especially that of Cladonia rangiformis) is clearly due to the over 10-year absence of grazing. The only lichen favored by moderate grazing is the legally protected C. magyarica. Short spells of low-intensity grazing can promote the species richness of cryptogams in the community.

The Efficiency of Lichens in Air Biomonitoring in Teleorman County

In this work, we collected samples of lichens from the oaks of Pădurea Troianul, in the area of Teleorman county, to analyze the air quality, using the lichen biodiversity index and its determining factor. We transplanted them to the points to be monitored and analyzed them to detect and quantify the concentration of heavy metals or other toxic substances accumulated in the lichen biomass. This research was conducted at transplant sites, where five sample sites were chosen. We investigated the concentrations of the heavy metals Cd, Pb and Hg, making a comparison between the concentrations indicated by lichens and conventional measurements. The sampling, observation and analysis of lichens, we carried out in the months of September, October and November 2021, because in September the temperatures are higher and the degree of precipitation is lower than in November, so we followed a development of lichens covering different periods in terms of temperature and humidity. The comparison was made starting from the contamination factors obtained and measured in the sampling station. The application of the biomonitoring method allows obtaining an exact index of the purity of the atmosphere based on the tolerance of the transplanted lichens, the results being obtained quickly.

Understanding heavy metal distribution in timberline vegetations: A case from the Gongga Mountain, eastern Tibetan Plateau

To quantify impacts of vegetation and topographic factors on heavy metal accumulation in montane forests, we assessed the spatial distribution and determined the sources of mercury (Hg), cadmium (Cd), lead (Pb), chromium (Cr), copper (Cu) and zinc (Zn) in timberline forests of Gongga Mountain. Our results show that vegetation type has little impact on the soil Hg, Cd and Pb concentrations. The soil concentrations of Cr, Cu and Zn are controlled by litter return, moss and lichen biomass, and canopy interception, with the highest concentrations in shrub forest. In contrast to other forests, the soil Hg pool in coniferous forest is significantly high due to the elevated Hg concentration and greater biomass production in litter. However, the soil pool sizes of Cd, Cr, Cu and Zn show a distinct increase along the elevation, which are attributed to the elevated heavy metal inputs from litter and moss, as well as the greater cloud water-induced atmospheric heavy metal depositions. The highest Hg concentrations of the aboveground parts of plant are in the foliage and bark, while the concentrations of Cd, Pb, Cr, Cu and Zn in the branch and bark are the highest. The decreased biomass density leads to a downward trend in the total vegetation pool sizes of Hg, Cd, Pb, Cr, Cu and Zn by 0.4–4.4 times with increasing elevation. The statistical analysis finally suggests that Hg, Cd and Pb mainly originate from anthropogenic atmospheric deposition, whereas Cr, Cu and Zn are mainly from natural sources. Our results highlight the importance of vegetation types and terrain conditions on distribution patterns of heavy metal in alpine forests.

Exploring the non-traditional fluorescence emission of non-conjugated polymers dots for sensing pesticides

The chemical sensing of pesticides is a high priority for a broad range of areas, including public health and environmental sustainability, since the pesticides have expanded dramatically in various agrarian operations. In this sense, the optical properties of non-conjugated polymer dots (NCPDs) can be a decisive advantage for sensing since the high sensitivity, fast response, and excellent photostability are very convenient properties. Here, we present the unique emission of NCPDs based on- β-glucan polymer, the major polysaccharide from the Usnea lichen biomass, which was explored for the sensing of the methyl parathion and dicloran pesticides due to the inner filter effect mechanism quenching. The sensing performance of the low-cost and eco-friendly NCPDs from renewable resources can shed light on the recent advances and applications of carbon-based nanomaterials involving non-traditional fluorescent emission systems, especially to monitor biologically and environmentally important analytes.

Influence of prescribed burning on reindeer winter pastures at landscape scale in northern Sweden: A modelling approach.

Whilst the re-introduction of fire can contribute to biodiversity conservation in Fennoscandian forests, the effects on reindeer herding remain uncertain. To assess the short- and long-term effects of prescribed burning on lichen supply in a productive forest landscape, we developed a model simulating lichen biomass available for reindeer grazing, covering 300years and 1500 pine stands, under different soil preparation scenarios, including different prescribed burning regimes and mechanical scarification. Our simulations revealed that burning 25-50% of yearly clear-cuts has the potential to stop, or even reverse, reindeer lichen decline at landscape scale after 70years, greatly surpassing the short-term losses caused by burning. No burning or burning 5% of yearly clear-cuts, as required by the FSC certification, compounded the negative effects of fire suppression and scarification on lichen. Compared to the scenario with no soil preparation, all our simulations resulted in a continuous decrease of lichen supply in Lichen-type stands, indicating that any form of disturbance in these habitats can strongly limit future gains.

Winter condition variability decreases the economic sustainability of reindeer husbandry.

Wild and semidomesticated reindeer are one of the key species in Arctic and subarctic areas, and their population dynamics are closely tied to winter conditions. Difficult snow conditions have been found to decrease the calving success and survivability of reindeer, but the economic effects of variation in winter conditions on reindeer husbandry have not been studied. In this study, we combine state-of-the-art economic-ecological modeling with the analysis of annual reindeer management reports from Finland. These contain local knowledge of herding communities. We quantify the occurrence probabilities of different types of winters from annual management reports and analyze the effects of this variation in winter conditions on reindeer husbandry using an age- and sex-structured bioeconomic reindeer-lichen model. Our results show that difficult winters decrease the net revenues of reindeer husbandry. However, they also protect lichen pastures from grazing, thereby increasing future net revenues. Nonetheless, our solutions show that the variability of winter conditions overall decrease the net income of herders compared to constant winter conditions. Low lichen biomass appears to make reindeer management more sensitive to the effects of difficult winter conditions. We also found that it is economically sensible to use supplementary feeding during difficult winters, but the net revenues still decrease compared to average winters because of the high feeding costs. Overall, our analysis suggests that the increasing variability of winter conditions due to climate change will decrease net revenues in reindeer husbandry. This decrease will still occur even if the most extreme effects of climate change do not occur. This study shows that combining a state-of-the-art bioeconomic model and practitioner knowledge can bring compatible insights, ideas, results, and a bottom-up perspective to the discussion.

Plant functional type aboveground biomass change within Alaska and northwest Canada mapped using a 35-year satellite time series from 1985 to 2020

Changes in vegetation distribution are underway in Arctic and boreal regions due to climate warming and associated fire disturbance. These changes have wide ranging downstream impacts—affecting wildlife habitat, nutrient cycling, climate feedbacks and fire regimes. It is thus critical to understand where these changes are occurring and what types of vegetation are affected, and to quantify the magnitude of the changes. In this study, we mapped live aboveground biomass for five common plant functional types (PFTs; deciduous shrubs, evergreen shrubs, forbs, graminoids and lichens) within Alaska and northwest Canada, every five years from 1985 to 2020. We employed a multi-scale approach, scaling from field harvest data and unmanned aerial vehicle-based biomass predictions to produce wall-to-wall maps based on climatological, topographic, phenological and Landsat spectral predictors. We found deciduous shrub and graminoid biomass were predicted best among PFTs. Our time-series analyses show increases in deciduous (37%) and evergreen shrub (7%) biomass, and decreases in graminoid (14%) and lichen (13%) biomass over a study area of approximately 500 000 km2. Fire was an important driver of recent changes in the study area, with the largest changes in biomass associated with historic fire perimeters. Decreases in lichen and graminoid biomass often corresponded with increasing shrub biomass. These findings illustrate the driving trends in vegetation change within the Arctic/boreal region. Understanding these changes and the impacts they in turn will have on Arctic and boreal ecosystems will be critical to understanding the trajectory of climate change in the region.

Lowland tundra plant stoichiometry is somewhat resilient decades following fire despite substantial and sustained shifts in community structure

ABSTRACT The Arctic is experiencing the greatest increase in average surface temperature globally, which is projected to amplify wildfire frequency and severity. Wildfire alters the biogeochemical characteristics of arctic ecosystems. However, the extent of these changes over time—particularly with regard to plant stoichiometries relative to community structure—is not well documented. Four years after the Yukon-Kuskokwim Delta, Alaska, experienced its largest fire season, aboveground plant and lichen biomass was harvested across a gradient of burn history: unburned (“reference”), 2015 burn (“recent burn”), and 1972 burn (“historic burn”) to assess the resilience of tundra plant communities to fire disturbance. Fire reduced aboveground biomass in the recent burn; early recovery was characterized by evergreen shrub and graminoid dominance. In the historic burn, aboveground biomass approached reference conditions despite a sustained reduction of lichen biomass. Although total plant and lichen carbon (C) and nitrogen (N) were reduced immediately following fire, N stocks recovered to a greater degree—reducing community-level C:N. Notably, at the species level, N enrichment was observed only in the recent burn. Yet, community restructuring persisted for decades following fire, reflecting a sustained reduction in N-poor lichens relative to more N-rich vascular plant species.

The synergism of lytic polysaccharide monooxygenases with lichenase and their co-immobilization on silica nanospheres for green conversion of lichen biomass

Enzyme-assisted valorization of lichenan represents a green and sustainable alternative to the conventional chemical industry. The recently discovered lytic polysaccharide monooxygenases (LPMOs) are essential components of state-of-the-art enzyme cocktails for lichenin bioconversion. The LPMOs named SpyTag fused LPMOs (AST) from Chaetomium globosum was functionally expressed in E. coli and exhibited 1.25-fold synergism with lichenase, whereas AST alone produced no detectable reducing sugars. HPLC results further confirm that AST does not alter the endogenous hydrolysis mode of lichenase but rather enhances its hydrolysis efficiency by disrupting the long chain of lichenan and releasing more reducing ends. To the best of our knowledge, this was the first report on the synergistic effect of LPMOs and lichenase, which may have great synergistic potential in the conversion of lichen biomass. Furthermore, a novel strategy for the covalently immobilizing AST and lichenase on silica nanoparticles (SNPs) from the cell lysate in a single step was proposed, which exhibited high activity recovery (82.9%) and high immobilization yield (94.8%). After 12 independent runs, about 67.4 % of the initial activity of the immobilized enzymes was retained. The resulted biocatalyst systems exhibited the green and sustainable strategy in the bioconversion of lichen biomass as well as other diverse polysaccharides.

Cryptogams and dwarf evergreen shrubs are vulnerable to nitrogen addition in a boreal permafrost peatland of Northeast China

AbstractAimBoreal peatlands are very sensitive to nitrogen (N) enrichment due to the low soil N availability. Our aim was to reveal how increased N availability altered plant composition in boreal permafrost peatlands with dense vascular plants (>50%).LocationGreater Khingan Mountains, Northeast China.MethodsA nitrogen addition experiment with four N addition levels (0, 3, 6, and 12 g N m−2 year−1) was conducted in a poor fen in the continuous permafrost zone with vascular plant coverage above 60%. Plant diversity, community composition, and above‐ground biomass were investigated after four, six, and eight years of N addition.ResultsNitrogen addition decreased species richness and diversity but enhanced total above‐ground biomass. Plant height determined the plants’ responses to N addition, and the magnitudes increased with N addition level and experimental duration. The relative coverage of high‐stature (>50 cm) species increased, but the relative coverage of low‐stature (<50 cm) species decreased with elevating N addition levels. When N addition proceeded, the relative coverage and above‐ground biomass of tall deciduous shrubs and nitrophilous grasses increased, whereas the relative coverage and above‐ground biomass of dwarf evergreen shrubs, mosses, and lichens declined. Regardless of N addition levels, cryptogams (i.e., mosses and lichens) and a dwarf evergreen shrub (Chamaedaphne calyculata) disappeared after eight‐year N addition.ConclusionsCryptogams and dwarf evergreen shrubs are highly vulnerable to increased N availability, and N enrichment‐induced biodiversity loss, especially the disappearance of cryptogams, will deteriorate ecosystem structure and function in boreal permafrost peatlands.

Host Density Influence on Regularly Fallen Lichen Species in Temperate Forests of Kumaun Himalaya

Lichens are very slow growing plants and play a significant role in forest ecosystem. In temperate areas lichens occur abundant on Quercus trees. After falling down lichens decompose into the soil and contribute in nutrient cycling. In the present study nine regularly fallen lichen species were recorded in three altitudinal zones. The density of fallen lichen was found maximum 95625 ind. ha -1 yr -1 at lower altitude followed by 70125 at higher altitude. The lichen biomass ranged between 5375 g ha -1 yr -1 to 7862.5 g ha -1 yr -1 in all the studied sites. Across the study sites seasonal highest biomass (11687 g ha -1 ) of fallen lichens was estimated in summer followed by 3198 in winter and 2950 during rainy season. Minimum biomass was recorded in spring season of about 2262 g ha -1 . Similarly, annual highest biomass of fallen lichens was recorded 7862.5 g ha -1 at lower altitude. Quercus leucotrichophora , Pinus roxburghii and Rhododendron. arboreum trees were observed as luxuriant lichens particularly in lower altitude. Parmotrema praesorediosum contributes a maximum 85.37% biomass of all species at lower altitude. At higher altitude R. conduplicans contributes maximum 31.13% followed by P. tinctorum (27.70%) and E. cirrhatum (19.31%) of the total fallen lichen biomass.

An artificial intelligence approach to remotely assess pale lichen biomass

Although generally given little attention in vegetation studies, ground-dwelling (terricolous) lichens are major contributors to overall carbon and nitrogen cycling, albedo, biodiversity and biomass in many high-latitude ecosystems. Changes in biomass of mat-forming pale lichens have the potential to affect vegetation, fauna, climate and human activities including reindeer husbandry. Lichens have a complex spectral signature and terricolous lichens have limited growth height, often growing in mixtures with taller vegetation. This has, so far, prevented the development of remote sensing techniques to accurately assess lichen biomass, which would be a powerful tool in ecosystem and ecological research and rangeland management. We present a Landsat based remote sensing model developed using deep neural networks, trained with 8914 field records of lichen volume collected for >20 years. In contrast to earlier proposed machine learning and regression methods for lichens, our model exploited the ability of neural networks to handle mixed spatial resolution input. We trained candidate models using input of 1 × 1 (30 × 30 m) and 3 × 3 Landsat pixels based on 7 reflective bands and 3 indices, combined with a 10 m spatial resolution digital elevation model. We normalised elevation data locally for each plot to remove the region-specific variation, while maintaining informative local variation in topography. The final model predicted lichen volume in an evaluation set (n = 159) reaching an R2 of 0.57. NDVI and elevation were the most important predictors, followed by the green band. Even with moderate tree cover density, the model was efficient, offering a considerable improvement compared to earlier methods based on specific reflectance. The model was in principle trained on data from Scandinavia, but when applied to sites in North America and Russia, the predictions of the model corresponded well with our visual interpretations of lichen abundance. We also accurately quantified a recent historic (35 years) change in lichen abundance in northern Norway. This new method enables further spatial and temporal studies of variation and changes in lichen biomass related to multiple research questions as well as rangeland management and economic and cultural ecosystem services. Combined with information on changes in drivers such as climate, land use and management, and air pollution, our model can be used to provide accurate estimates of ecosystem changes and to improve vegetation-climate models by including pale lichens.

Estimating lichen biomass in forests and peatlands of northwestern Canada in a changing climate

ABSTRACT Climate warming in the North could lead to lichen decline within critical woodland caribou habitat. We used repeat measurements of sixty-nine plots over ten years (2007–2008 and 2017–2018) to assess lichen biomass changes under a warming climate along a latitudinal/climatic gradient in northwestern Canada. We compared lichen biomass on sensitive landscape features, including peat plateaux (permafrost-containing bogs), areas of permafrost thaw within the peat plateaux (collapse scars), and low-productivity upland forests occurring on mineral soils. Field-based measures of lichen cover and height were coupled with samples of lichen biomass to develop biomass prediction equations. The optimal model incorporated both cover and height, with landscape feature as a covariate. Although height significantly improved the equation fit, models were successfully developed with cover alone. Modeled lichen biomass differed significantly between landscape features, declining from peat plateau (502 g m−2) to upland forest (54.0 g m−2) and collapse scar (0.690 g m−2) environments. In the absence of permafrost collapse at any monitoring location, lichen biomass declined significantly over the ten years for peat plateaux (−75.6 g m−2) and upland forests (−17.5 g m−2). These results will be important for quantifying landscape-level lichen biomass changes under climate warming in boreal and subarctic environments.

Abundance and accessibility of forage for reindeer in forests of Northern Sweden: Impacts of landscape and winter climate regime.

The survival of reindeer during winter, their period of greatest food stress, depends largely on the abundance and accessibility of forage in their pastures. In Northern Sweden, realized availability of forage is notably affected by snow conditions and the impacts of forestry. While these factors have been examined in isolation, their combined effect has, to the best of our knowledge to date, not been researched. In this study, vegetation surveys and analysis of snow conditions were undertaken in forest stands at various stages of recovery from clear‐cutting. The variation in abundance and growth of understory species edible by reindeer, such as lichen, was noted as forests matured. The barrier effect of ice lenses in the snow was also measured in these stands. Lichen biomass was significantly affected by a combination of stand maturity, understory vegetation height, and lichen height. Soil disturbance from the processes of felling and competition in the vegetation communities recovering from this disturbance were identified as key drivers of change in lichen biomass. Overall, clear‐cut forests had some of the greatest prevalence of ice lenses in the snow column, and forage availability at these sites was up to 61% less than in mature stands over 58 years in age. It is suggested that alternative silviculture methods are investigated for use in this reindeer herding region, as frequent clear‐cutting and consequent reduction in the average forest stand age and maturity class may be detrimental to reindeer grazing, reducing both abundance of forage, and access to it during winter.

Use of Fungal Mycelium as Biosupport in the Formation of Lichen-like Structure: Recovery of Algal Grown in Sugarcane Molasses for Lipid Accumulation and Balanced Fatty Acid Profile.

In this study, a lichen-like structure was obtained through the production of a unique biomass, formed by algae cells of Scenedesmus obliquus adhering to the mycelium of filamentous fungal Mucor circinelloides. This structure was composed in two steps; in the first one, microalgal cells and spores were incubated separately, and in the second one, after 72 h of growth, isolated, mature mycelium was harvested and added to cell culture. For spores’ incubation, a culture medium containing only 2 g·L−1 of glucose and minerals was used. This culture medium, with low sugar content, provided a fungal biomass to the anchorage of microalgae cells. WC medium was used without and with sugarcane molasses supplementation for microalgae cells’ incubation. The lichen-type structure that was formed resulted in 99.7% efficiency in the recovery of microalgae cells and in up to 80% efficiency in the recovery of algae biomass in the lichen biomass composition. In addition, the resulting consortium attained a satisfactory lipid accumulation value (38.2 wt%) with a balanced fatty acid composition of 52.7% saturated plus monounsaturated fatty acids and 47.4% polyunsaturated fatty acids. Since fungal species are easy to recover, unlike microalgae, the lichen-like structure produced indicates an efficient low-cost bioremediation and harvesting alternative; in addition, it provides an oleaginous biomass for various industrial applications.

Sorption of cobalt and zinc from single and binary metal solutions by Evernia prunastri

Non-living lichen Evernia prunastri was studied as biosorbent material for zinc and cobalt removal from single and binary metal solutions. Sorption equilibrium of Zn2+ and Co2+ ions was reached within 1 hour. Both cobalt and zinc biosorption was not pH dependent within the range pH 4-6 and negligible at pH 2. The experimental results were fitted to the Langmuir, Freundlich, Redlich-Peterson and Langmuir-Freundlich adsorption isotherms to obtain the characteristic parameters of each model. The Langmuir, Redlich-Peterson and Langmuir-Freundlich isotherms were found to well represent the measured sorption data. According to the evaluation using the Langmuir equation, the maximum sorption capacities of metal ions onto lichen biomass were 112 μmol/g Zn and 97.2 μmol/g Co from single metal solutions. E. prunastri exhibited preferential uptake of zinc from equimolar binary Zn2+ - Co2+ mixtures within the range 50 – 4000 μM. Even thought mutual interference was seen in all Co-Zn binary systems. To evaluate the two-metal sorption system, simple curves had to be replaced by three-dimensional sorption surface. These results can be used to elucidate the behavior of lichens as bioindicators of cobalt and zinc pollution in water and terrestrial ecosystems.

Stand-Level Variation Drives Canopy Water Storage by Non-vascular Epiphytes Across a Temperate-Boreal Ecotone

Epiphytes, including bryophytes and lichens, can significantly change the water interception and storage capacities of forest canopies. However, despite some understanding of this role, empirical evaluations of canopy and bole community water storage capacity by epiphytes are still quite limited. Epiphyte communities are shaped by both microclimate and host plant identity, and so the canopy and bole community storage capacity might also be expected to vary across similar spatial scales. We estimated canopy and bole community cover and biomass of bryophytes and lichens from ground-based surveys across a temperate-boreal ecotone in continental North America (Minnesota). Multiple forest types were studied at each site, to separate stand level and latitudinal effects. Biomass was converted into potential canopy and bole community storage on the basis of water-holding capacity measurements of dominant taxa. Bole biomass and potential water storage was a much larger contributor than outer canopy. Biomass and water storage capacity varied greatly, ranging from 9 to >900kg ha–1 and 0.003 to 0.38 mm, respectively. These values are lower than most reported results for temperate forests, which have emphasized coastal and old-growth forests. Variation was greatest within sites and appeared to reflect the strong effects of host tree identity on epiphyte communities, with conifer-dominated plots hosting more lichen-dominated epiphyte communities with lower potential water storage capacity. These results point to the challenges of estimating and incorporating epiphyte contributions to canopy hydrology from stand metrics. Further work is also needed to improve estimates of canopy epiphytes, including crustose lichens.