Biomagnetic monitoring of urban air pollution using moss bags (Sphagnum girgensohnii)

Active moss biomonitoring is widely applied in polluted areas for monitoring of airborne particle-bound trace element pollution. This study explored the suitability of the moss Sphagnum girgensohnii for biomagnetic monitoring in cities. To this end S. girgensohnii moss bags were exposed at three different microenvironments characterized by heavy traffic – street canyons, a city tunnel and parking garages during the summer and autumn of 2011 in the city of Belgrade. The ferro(i)magnetic PM fraction in the moss samples was quantified by Saturated Isothermal Remanent Magnetization (SIRM) and the measured values were compared with the trace element concentration in the moss samples. SIRM values were significantly different across the considered urban microenvironments. Moreover, a high correlation between moss SIRM values and concentrations of Al, Ba, Co, Cr, Cu, Fe, Ni and Pb was found. These results demonstrate that moss bags can be effectively applied for biomagnetic monitoring of the spatio-temporal distribution of road traffic and vehicles derived pollutants in urban areas.     

Lead adsorption capacity of some moss species used for heavy metal analysis

Mosses, covering about 23,000 species of all land plants in the world, have been widely used as an indicator of heavy metal pollution in many studies. A crucial part in these researches is to regularize the adsorption capacities of different moss species obtained from different regions to objectively compare the pollution levels. In this study, we have first analyzed the lead adsorption capacities of six different moss species by means of using column filled with Amberlite XAD-2000 resin method. The adsorption capacities of the studied six mosses are found in descending order as Eurhynchium striatum, Hypnum cupressiforme, Pleurozium schreberi, Eurhynchium striatulum, Homalothecium sericeum and Thuidium tamariscinum. Then, we have regularized the Pb adsorption levels for the moss species obtained from different regions along one of the important coast highway in Turkey, namely Sarp-Samsun highway, with respect to the determined adsorption capacities.     

黄山藓类植物区系

对黄山进行了多次实地调查、考察和标本采集,经分类鉴定,收集整理有关黄山藓类的研究资料,目前黄山藓类植物有46科、135属、401种（包括7亚种和22变种）,与20世纪50年代陈邦杰等以及后来对黄山的调查研究结果相比,藓类植物增加了4科、28属、184种;科内种数（≥15种）优势科有10个,属内种数（≥6种）的优势属有18个。黄山藓类植物地理成分类型复杂,东亚成分（包括中国特有）占37.82%,温带成分占35.13%,热带、亚热带成分占26.75%,表现出明显的由亚热带向温带过渡的特性。     

固定沙丘结皮层藓类植物多样性及固沙作用研究

 根据对沙坡头固定沙丘生物结皮的物种调查、鉴定及盖度和生物量的研究,藓类植物共2科,7属,16种,以真藓（Bryum argenteum）为优势种。随着固沙时间的延长,生物结皮中藓类和藻类总盖度呈上升趋势;沿不同年代固定沙丘坡面向上等距离梯度,藓类盖度显著下降,而藻类盖度则平稳上升。对不同年代固定沙丘生物结皮优势种真藓的生物量和固沙量的测定表明,随沙丘固定年代的增加,真藓的生物量和固沙量增加,50年代固沙区结皮层真藓生物量是944.03 kg·hm-2,固沙量是3.925×104 kg·hm-2,但固沙率随时间的增加而减少。真藓的饱和吸水量与生物量呈正相关,50年代固定沙丘藓类结皮层可吸水7.06×103 kg·hm-2,说明藓类结皮层具有很强的吸水和保水能力,对于干燥少雨的沙漠地区具有十分重要的生态学意义。     

Response of the moss Racomitrium lanuginosum to changes in sheep grazing and snow‐lie due to a snow‐fence

Question: What are the responses of Racomitrium lanuginosum moss to altered snow‐lie and sheep use? Location: ACarexbigelowii‐Racomitrium lanuginosum heath on a Scottish montane plateau affected since 1986 by a fenced ski corridor. Methods: Permanent quadrats were set up along transects 45 m long perpendicular to the snow‐fence. Cover was assessed over a 12‐year period from 1990. Pellet‐group clearance counts provided data on sheep usage between 1990 and 1996. Snow‐lie was mapped in the springs of 1991–1996. Results: The snow‐fence created a gradient in sheep use and altered the duration of snow‐lie. At the start of monitoring Racomitrium cover was lower immediately adjacent to the fence, and after 12 years its cover was significantly reduced within 10 m of the fence. Further away from the fence Racomitrium cover was relatively stable. The loss of Racomitrium was correlated both with increased snow‐lie and heavier sheep usage. Grass cover increased near the fence and was related to sheep use. Dicranum fuscescens responded differently to Racomitrium, increasing significantly near the fence. Conclusions: We found that changes in snow‐lie and grazing pressure quickly brought about vegetation change in this montane ecosystem. Racomitrium was the most sensitive species to the changes in grazing and snow‐lie caused by the fence, having the biggest initial changes. Loss of Racomitrium permitted increases of species more resistant to grazing including Dicranum fuscescens and grasses.     

Characterization of diverse plant communities in Aspen Parkland rangeland using LiDAR data

Question: How effective is high-resolution airborne LiDAR technology for quantifying biophysical characteristics of multiple community types within diverse rangeland environments? Location: Native Aspen Parkland vegetation in central Alberta, Canada. Methods: Vegetation within 117 reference plots stratified across eight types, including forest, shrubland, upland grassland and lowland meadow communities, were assessed in 2001 for the height, cover and density of vegetation within various strata (herb, shrub and tree layers). Actual ground data were subsequently compared against modelled values for each community type and strata derived from the analysis of airborne LiDAR data obtained in 2000. Results: LiDAR data were effective for quantifying vegetation height, cover and density of the overstory within closed- and open Populus forest communities. However, LiDAR measurements typically underestimated the height and cover of shrublands, as well as most of the herbaceous communities. Analysis of LiDAR intensity data indicated reflectance generally decreased as LiDAR sampling points moved upwards from the ground to the vegetation canopy. Conclusions: While LiDAR technology is useful for characterizing deciduous forest properties, the quantification of understory vegetation characteristics, as well as those of individual shrublands and grasslands, was more limiting. Further refinements in analysis methods are necessary to increase the reliability of characterizing these communities.     

Host-specificity of moss-associated fungal communities in the Ny-Ålesund region (Svalbard,High Arctic) as revealed by amplicon pyrosequencing

Fungal communities play a significant role in regulating ecological processes in the Arctic tundra. However, the extent to which the Arctic moss species and host types (moss, lichen and vascular plant) determine the richness, diversity, and composition of fungal communities at a local scale has not been quantitatively explored. Using 454 pyrosequencing in the current study, we characterized the fungal communities associated with six moss species (Andreaea rupestris, Bryum pseudotriquetrum, Hymenoloma crispulum, Polytrichastrum alpinum, Racomitrium lanuginosum, and Sanionia uncinata) and compared them with fungal communities associated with lichens and vascular plants in the Ny-Ålesund region (High Arctic). Host-species preference had greater explanatory power than geographical factors (longitude, latitude, elevation) in shaping moss-associated fungal communities. Fungal communities associated with mosses differed significantly from those associated with vascular plants and lichens, suggesting specificity of the fungal communities among three host types. Pairwise comparison analysis also indicated that the relative abundance of many taxonomic groups (e.g., Chaetothyriales, Leotiales, Catenulifera, Alatospora, and Toxicocladosporium) significantly differed between mosses and the other two host types. These results suggest host factors significantly affect the distribution of the fungal species associated with these moss species in the local-scale Arctic tundra.     

Nitrogen cycling in an Antarctic ecosystem 2. Estimation of the amount of nitrogen fixation in a moss community on East Ongul Island

Nitrogen fixation by cyanobacteria in a moss community on East Ongul Island (69°00'S 39°35'E), Antarctica was investigated using the acetylene reduction method. The mean acetylene reduction rate at 10°C and 200 μE·m⁻²·s⁻¹ photosynthetically active radiation was 7.12 nmol C₂H₄ per square centimeter of moss community per hour. The effects of temperature, radiation, desiccation and rehydration on the acetylene reduction rates were examined. A simple predictive model was constructed in order to estimate the amount of nitrogen fixed in the field. Using this model, the daily amount of nitrogen fixation was calculated from microclimatic data (temperature and radiation) measured in the experimental field at Syowa Station on East Ongul Island between 1983 and 1984. The cumulative amount of nitrogen fixation in the growing season during this period was estimated to be 329 mg N per square meter of moss community. It is suggested that nitrogen fixation by cyanobacteria in the moss community is important as a nitrogen source for the community growth on East Ongul Island.