No description available.

Testate amoebae (Protozoa: Rhizopoda) are particularly abundant in peatlands. Previous studies have used testate amoebae in palaeoenvironmental studies, but have used qualitative data only, so that results are expressed only in terms of 'wet', 'dry' or 'moist'. This study uses testate amoebae to derive quantitative reconstructions of mire surface wetness for part of the Holocene and is split into two parts. The first part of this study modelled the responses of individual testate amoebae species to environmental variables on ombrotrophic mires, since the peatland-climate link makes these habitats the one of the most useful in palaeoclimate reconstructions. 163 samples of modern testate amoebae faunas were obtained from 9 ombrotrophic mires across Britain. Environmental variables (mean annual water table, moisture content, dissolved organic carbon, pH, Ca2+ , Mg2+ , SO42- , Cl-, conductivity and host plant species) were measured. A hydrological monitoring programme on an ombrotrophic mire on Dartmoor provided a detailed record of hydrology and selected water chemistry over a year and identified the season most representative of mean annual environmental conditions. Weighted averaging regression applied to the faunas provided absolute moisture content and mean annual water table optima for 38 common testate amoebae species. In the second part of the study weighted averaging calibration was used to derive transfer functions from the modern species' optima. From these, mean annual water table and substrate moisture content were reconstructed for the top 100 cm of a selected fossil peat core from Bolton Fell Moss, Cumbria. These reconstructions were compared with those derived from plant macrofossil and peat humification analyses. Testate amoebae provided a further insight into the decline of Sphagnum imbricaturn, clarified noisy areas of the existing palaeohydrological record and suggested that hydrological changes at Bolton Fell Moss were likely to have been gradual, rather than the sudden event implied by the plant macrofossil record. This study demonstrates the future potential of testate amoebae as palaeohydrological indicators. Expansion of the modern data set in terms of species composition and geographical extent, further applications of testate amoebae into multi-proxy palaeohydrological reconstructions and taxonomic refinements are suggested to improve the technique further.

Human activity has affected metal emissions to the atmosphere on a global scale for several thousand years, resulting in widespread contamination of the environment with toxic heavy metals such as Pb and Hg, thereby threatening both human and environmental health. In recent years ombrotrophic peat bogs have been used to study the changing rates and sources of atmospheric metal deposition, as they receive all their water and nutrients from the atmosphere by dry and wet deposition alone. Cores from such bogs have proved especially useful as archives of atmospheric Pb deposition as Pb is essentially immobile in ombrotrophic peat. The work described in this thesis is primarily concerned with the use of ombrotrophic peat bogs to investigate environmental contamination in Scotland during pre-industrial, industrial and post-industrial (i.e. ca. post-1970 A.D.) times. Cores were collected from ombrotrophic peat bogs at four different geographical locations (Carsegowan Moss, SW; Flanders Moss, W Central; The Red Moss of Balerno, E Central; Turclossie Moss, NE) in Scotland. Air-dried peat samples were dry-ashed and dissolved using microwave-assisted HF IHN03 digestion. Elemental concentrations (e.g. AI, As, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, P, Pb, S, Sb, Sc, Se, Ti, V, Y, Zn and Zr) and Pb isotope ratios (e.g. 206PbP07Pb) were determined using ICP-OES and ICP-MS as appropriate. For Hg determination, samples were digested with HN03/H2S04 and then analysed by CV AAS. Certified reference materials (e.g. Ombrotrophic Peat (NIMT/UOE/FM001), Canadian Peat (1878 P), Bush Branches and Leaves (DC73349), Peach Leaves (GBW 08501) and Coal (BCR CRM No. 40 and NBS SRM 1635) were used for quality control purposes. The distribution and behaviour of the potentially toxic trace elements (As, Cd, Co, Cr, Cu, Hg, Ni, Sb, Se, V and Zn) and of major elements (Ca, Fe, Mg, Mn, P and S) within the four ombrotrophic peat bogs was investigated and there was strong evidence that Ca, Fe, Mg, Mn, P, S, Se and Zn were mobile in ombrotrophic peat, while As, Cd, Co, Cr, Cu, Hg (at least during industrial and post-industrial periods), Ni, Sb and V, like Pb, were essentially immobile in ombrotrophic peat. Deposition records of conservative lithogenic elements (e.g. concentrations of AI, Sc, Ti, Y and Zr) that occur predominantly in soil dust were also investigated and the chosen conservative elements Sc, Ti and Zr were used in calculations to estimate anthropogenic enrichments of As, Cd, Co, Cr, Cu, Ni, Pb, Sb and V in peat bog profiles. 210Pb- and 14C- dated peat cores were used to reconstruct historical records of atmospheric anthropogenic As, Cd, Co, Cr, Cu, Ni, Pb, Sb and V deposition (since the pre-Roman (i.e. to ca. 380 B.C.)/Roman period) and atmospheric Hg deposition (since the onset of the industrial period) across Scotland. For Pb, on the basis of Pb isotopic composition (e.g. 206PbP Pb), clear indications of contamination during the preRoman/Roman and Mediaeval periods were attributed to the mining and smelting of Pb ores (from Britain and elsewhere in Europe). During the industrial and post-industrial periods, variations in the relative importance of contributions of anthropogenic Pb from different sources were apparent. From ca. the early 17th century A.D. at three of the peat bog sites, the mining and smelting of indigenous Scottish Pb ores, until the early 20th century A.D., were found to be the most important sources of anthropogenic Pb deposition. In contrast, at the most southerly site (Carsegowan Moss), influences from the use of both British Ph ores and imported Australian Ph ores (in more southern parts of Britain) since the late 19th century A.D. were evident. At each of the sites, the increasing importance of Australian-Ph-influenced car-exhaust emissions from the 1930s to late 1990s A.D., along with significant contributions from coal combustion (until the late 1960s A.D.) was evident. For Sb, in general, similarities between the major trends in the concentration profiles of anthropogenic Sb and Ph suggested common sources of these two elements. Perturbations in the anthropogenic Sb/Pb ratios since ca. 1800 A.D., however, were attributed to temporal variations in the relative importance of atmospheric emissions from different sources such as Ph ore mining/smelting, coal combustion and, in recent decades, automobile-related use of compounds of Ph (in leaded petrol) and of Sb (in brake linings). For Hg, in general, during the industrial and post-industrial periods, coal combustion and waste incineration, respectively, were likely to be the most important sources of Hg. For As, clear indications of contamination during the Mediaeval period were probably attributable to the mining and smelting of Ph and Cu ores, and for As, Cd, Co, Cr, Cu, Ni and V, during the industrial and post-industrial periods, a variety of sources (e.g. metallurgical activities, coal and oil combustion, use of phosphate fertilisers and waste incineration) were important to varying extents. Also, in recent years, atmospheric Cu emissions from automobile-related use of compounds of Cu (in motor oil, brake linings and tyres) may have been important. Inter-site and inter-elemental comparison of records of atmospheric metal deposition across Scotland indicated that, in general, atmospheric As, Cr, Hg, Ph and Sb deposition was greatest during the industrial period (between the late 1880s and late 1960s A.D.) and atmospheric Cd, Co, Cu, Ni and V deposition was greatest during the industrial and post-industrial periods (between ca. 1900 and the early 2000s A.D.), although increases in As, Co, Cr, Hg, Ph and Sb deposition were earliest (during the late 19th and early 20th century A.D.) at the most southerly site (Carsegowan Moss). During the industrial and post-industrial periods, levels of As, Ph and Cd contamination were generally highest in the south of Scotland, Cu, Co and Sb in south and central Scotland, and Cr, Ni and V in central Scotland. Overall, the existence of a south to north As, Cd, Co, Cr, Cu, Ni, Ph, Sb and V pollution gradient in Scotland was evident.

No description available.

Methane is a radiatively active, naturally occurring atmospheric trace gas which is thought to account for as much as 19% of the enhanced greenhouse effect. Ice core studies have shown that the atmospheric concentration has more than doubled since pre-industrial times. Wetlands are the largest natural source of atmospheric methane, contributing around 21 % of the annual global flux. The magnitude of various sources of methane is still poorly defined. Stable isotope measurements are increasingly being used to constrain global budgets of atmospheric trace gases because isotopic analysis provides a much clearer picture of global atmospheric chemistry than C~ concentration measurements alone. Conventional analytical techniques for studying dual stable isotopic composition of methane (813e and 8D) require prohibitively large quantities of CH4 for analysis. At the Planetary Sciences Research Institute of the Open University, a highly sensitive static mass spectrometer has been developed which uniquely uses CH4 as the analyte. The method requires only 8 ng ofCH4 for analysis «10 ml ambient air), making replicated measurements of the isotopic composition of CH4 emissions from wetlands feasible for the first time. Methane emissions from an ombrotrophic mire in Snowdonia have been measured over 2 years, (1995-1997) and analysed for 817M. Parallel laboratory studies have also been conducted, to constrain the effects of environmental variables such as peat temperature and water table depth. The presence of vascular plants enhanced methane flux. In the field, methane flux showed seasonal variation. Peat temperature and water table depth could account for 68% of this variation. The isotopic composition of methane flux from the ombrotrophic mire also exhibited seasonal variation, with 817M ranging from -34 to -17%0. The lowest values were observed in summer and the highest in winter. Variations in the isotopic composition of peat water are unlikely to account for more than a 2%0 shift in 817M. Although there was a strong correlation between peat temperature and methane isotopic composition in the field, peat temperature is thought to be an indirect effect, because in laboratory studies this relationship was absent. There was no relationship between water table depth and 817M. It was concluded that the seasonal variation in the isotopic composition of methane emission is linked to the plant growth cycle. Comparison of 817M values determined for methane emissions in Snowdonia with published 813C and 8D data leads to the conclusion that methane is produced mainly by C02 reduction. Contrasting terrains in a paisa mire in the Arctic region of Finland exhibited methane _ emissions with distinct 817M values: lakes, +4.8 ±1.2%0; pools, -3.9 ±O.IO/oo and hummocks, -28.6 ±5.8%0 . From these isotope data it was concluded that in pool and lake sediments the methanogenic pathway is acetate fermentation, while in hummocks methane is produced by CO2 reduction. This study is the first investigation of the stable isotopic composition of methane emissions from wetlands in the UK. The data collected in Snowdonia, and in Finland, show the need for systematic, year round isotopic analysis of methane emissions, if isotope data are to be used in constraining the global methane budget.

Elevated levels of arsenic (As) in soils and water around the world are both a significant human health and environmental hazard. With increasing global water demands, there is a requirement to further the understanding of the biogeochemical cycling of As from soils and sediments. This thesis focussed on exploring the environmental controls on the occurrence and subsequent mobility of As in a range of natural environments. Arsenic was found to undergo mobilisation from both river sediments and upland peats under changing environmental conditions. The transport of As was found to be correlated with both iron (Fe) and organic carbon (OC), however temporal changes in both sediment/soil composition and movement of water through catchments have a important role in controlling the ultimate transport of As within the environment. A range of investigative methods were employed to study the occurrence and mobility of As within the river sediments of the Allier and Loire Rivers (France), including sequential extraction procedures and batch incubation studies. Arsenic was associated with the reducible phases of sediments, indicating the major role of Fe(oxy)hydroxides in the storage of As in river sediments. In addition to the presence of labile As, the rapid release of As was dependent on the initial sediment composition. Temporal changes in sediment composition may therefore play an important role in controlling the movement of As within fluvial systems. The combination of lead (Pb) and strontium (Sr) isotopic analysis with sequential extraction studies of sediments from the Loire and Allier Rivers was able to determine the relative dominance of granites and basalts within the sediments. This approach provided a first order study on which to better understand the mineral origins of the sediments. The analysis of multiple Pb isotopes was able to eliminate possible anthropogenic contribution to contamination within the sediments, confirming the importance of geogenic cycling of As within the rivers. Information on the origin of mineral formation was obtained through 87Sr/86Sr isotopic analysis, with the formation of Fe-minerals not occurring uniformly along the course of the rivers. While the Sr within the sediment phase targeting well-crystallised Fe(oxy)hydroxides was in equilibrium with the sampled river water, the formation of amorphous Fe minerals was likely occurring in waters upstream of the study sites, within the Massif Central. Total concentration profiles peat from two subcatchments within the Peak District (United Kingdom) provided evidence for both the retention and post depositional movement (PDM) of As within the solid phase, dependent on local conditions. For the first time, the partitioning of As was determined within ombrotrophic peat, and found to be in contrast to Pb, with oxidisible As (likely associated with organic matter) dominating, while Pb was found predominantly within the reducible sediment phase. High temporal resolution monitoring of the organic-rich streamwater draining the peat showed the transport of As was variable, with As found largely in the soluble form despite extensive peat erosion. The evidence for PDM, and the subsequent soluble transport of As demonstrated the importance of biogeochemical processes in releasing As from the solid phase. Once mobilised, both the ratio of Fe:OC and the form of Fe were found to be factors controlling transport of As, with the flushing of stored porewaters an important contribution to As transport from the peat. Despite OC-rich waters, the occurrence of high concentrations of Fe may dominate control of As within the aqueous phase. At relatively high (>0.2) Fe:OC ratios, the particle size distribution of As was closely correlated with that of >1um Fe, although the presence of dissolved and colloidal As was found even within these waters. Given the temporal variability of As transport within the streams, knowledge of the mixing order and ratio between Fe, OC, and As within natural waters may be required for prediction of the mobility and ultimate fate of As.

The functional hydrological components of the ombrotrophic mire water balance are, considered in terms of their ecological relevance. It is proposed that numerical models provide a suitable framework for mire hydro-systems and their potential as quantitative tools for mire restoration and conservation management is demonstrated. Existing models previously applied to mires are reviewed. The USGS 3-D groundwater model MODFLOW is selected and a new shallow surface and groundwater model GSHAW5 is developed for application to mires. Extensive ecohydrological case studies are undertaken at two mire sites and the models are tested using data collected at the sites. Field studies at Wedholme Flow, Cumbria, extended over four years and the data collected were combined with historical records to form a 10-year hydrological data set. Studies at Trough End Bog, Northumbria, extended over a 3-year period. Topographic, soil and vegetation surveys were carried out at both sites. Watertable fluctuation was recorded manually on a weekly basis and electronically at a 20-minute interval along with automatic meteorological records. New hydrometric techniques were developed in the Surface Water Monitoring Plot, SWaMP, constructed at Trough End to record hydrological exchanges within the hummock-hollow complex of the mire acrotelm. The models operate on very different spatial and temporal scales. GSHAW5 is applied to reproduce ground and surface exchanges in the acrotel. MODFLOW is used to simulate large-scale exchanges in undisturbed areas and between regenerating and active peat cutting areas. Predictive MODFLOW simulations are used to examine the impact of different peat cutting regimes on mire hydrology and potential regeneration. Both models produce simulations strongly correlated to observed hydrological exchanges. The usefulness of numerical models as tools for mire management is considered in light of the model test results from both case studies. It is concluded that both models provide insight and quantitative estimates of hydrological exchanges not possible by other means. MODFLOW simulations reveal considerable water loss from the Wedholme Flow mire reserve to an active peat cutting area. Simulations of Trough End bog reveal hydrological acrotelm processes strongly related to vegetation assemblages. An extensified GSHAW5 acrotelm model is recommended for the simulation of intact ombrotrophic mires.

Peatlands in the sub-humid Boreal Plains of Alberta exist at the limit of their climatic tolerance and are vulnerable to wildfire. This is especially true at the interface between the peatland and forestland (margins) due to water table fluctuation resulting in high peat bulk density and low moisture content during dry periods in some peatland systems. Deep burning at the margins may reduce a peatland's ability to recover to its previous state, leading to a reduction in area and/or collapse following fire, and bringing into question the long-term stability of Boreal Plains peatlands on the landscape under current and future climate predictions. Previous research has identified small peatlands located at a mid-topographic position on coarse sediments as hotspots for deep burning, as these peatlands are not regularly connected to regional groundwater flow. The ability of these peatland systems to recover lost carbon from both the interior and margin within the fire return interval, however, has not yet been investigated. This thesis further examines the relationship between surficial sediment assemblages and the impact of wildfire on overlying peatlands through assessment of organic soil carbon accumulation following wildfire across the Boreal Plains landscape. Peatland organic soil recovery along a chronosequence was assessed in the interior and margin of 26 ombrotrophic bogs located at various positions on the post-glaciation landscape of Northern Alberta using estimates of organic soil carbon accumulation calculated through loss on ignition of peat above the uppermost charcoal layer in peat cores from each site, as well as characterization of peat properties along a transect from the adjacent forestland into the peatland interior. Soil organic carbon accumulation with time since fire was greater in studied peatland interiors than margins. Underlying sediments were found to have little effect on total soil organic carbon accumulation in the interior and margins of the studied peatlands, indicating that organic soil carbon accumulation rates following wildfire estimated in this study can be extended to ombrotrophic bogs across the Boreal Plains landscape. Though total soil organic carbon accumulation following wildfire does not appear to be influenced by hydrogeological setting, the ability of a peatland to recover the quantity of carbon lost within the fire return interval will be dependent on the amount of carbon which was released through smouldering, which is influenced by hydrogeological setting for peatland margins. Based on published measurements of organic soil carbon loss during wildfire and organic soil carbon accumulation rates estimated in this thesis, peatlands located at topographic lows on coarse grained glaciofluvial outwash sediments or on low-relief, fine grained sediment deposits from glaciolacustrine or subglacial paleoenvironments are predicted to be resilient to wildfire on the Boreal Plains landscape. Peatlands which experience severe smouldering at the margins, such as ephemerally perched systems on glaciofluvial outwash sediments, will likely undergo permanent loss of legacy carbon stores. The resilience of peatlands which are perched above regional groundwater on glaciofluvial outwash or stagnant ice moraine deposits is unknown at this time; further investigation into water table dynamics, margin peat properties, and smouldering depths in these systems is required. Identification of peatland systems which are at risk of permanent carbon loss at the margins and those which are most resilient to wildfire in this thesis can be applied to wildfire management strategies and the design of peatland systems for reclamation of oil sands leases. The stability of natural and created peatlands through time on a landscape where wildfire is frequent is an important consideration in terms of both lasting ecosystem services and the potential risk to fire suppression and community safety that vulnerable systems pose. / Thesis / Master of Science (MSc)

L’usage des véhicules tout-terrain (VTT) est largement répandu en Minganie, municipalité régionale de comté reconnue pour ses grandes étendues de tourbières. Ce mémoire vise à comprendre les effets de cette perturbation linéaire en déterminant la distance d’influence des sentiers de VTT sur la végétation et les caractéristiques physiques des tourbières. De plus, il vise à déterminer l’ampleur de l’impact en fonction des caractéristiques des sentiers (largeur, profondeur et nombre de sillons). Répartis dans un rayon de 200 km autour de la municipalité de Havre-Saint-Pierre, 18 transects d’échantillonnage ont permis de constater un effet localisé et limité des sentiers de VTT sur la végétation et les variables abiotiques. Un sol dénudé et une plus grande densité de la tourbe ont été observés à l’emplacement du sentier. De plus, une couverture végétale plus faible a été constatée dans les sentiers, car près du quart des espèces ne résistent pas aux passages des VTT. Quatre espèces indicatrices associées aux placettes hors sentier (K. angustifolia, R. groenlandicum, C. rangiferina et S. fuscum) semblent partager des caractéristiques communes (p. ex. : forme érigée, branches basses et ligneuses, thalle friable) les rendant moins tolérantes aux passages des VTT. Certains sentiers couvrent des zones très étendues, surtout s’ils sont dans des zones fortement humides, de sorte que l'impact global du passage des VTT, bien que limité aux sentiers eux-mêmes, peut être très important localement. Puisque l'utilisation des VTT est une pratique en croissance dans la région, une gestion de leur utilisation dans les milieux sensibles ou une sensibilisation des utilisateurs de VTT sur les conditions des tourbières pourrait réduire les effets négatifs et assurer un usage durable pour maintenir les services écologiques fournis par les tourbières. / All-terrain vehicles (ATVs) are widely used in Minganie, a region known for its vast expanses of peat bogs. This thesis aims to understand the effects of this linear disturbance by determining the distance of influence of ATV trails on the vegetation and physical characteristics of the peatlands. In addition, it aims to determine the magnitude of the effect based on trail characteristics (width, depth, and number of ruts). Located within a 200 km radius of the municipality of Havre-Saint-Pierre, 18 sampling transects revealed a localized and limited effect of ATV trails on vegetation and abiotic variables. Bare soil and higher peat density were observed at the trail location. In addition, lower vegetation cover was observed on the trails, as nearly a quarter of the species did not survive the ATV passages. Four indicator species associated with the off-trail plots (K. angustifolia, R. groenlandicum, C. rangiferina, and S. fuscum) appear to share common characteristics that make them less tolerant of ATV traffic (i.e., erect form, base-branched woody stems, brittle thallus). Some trails cover wide areas, especially if they are in very wet areas, hence the global impact of ATV passage, while limited to the trails themselves, can be quite severe locally. Since ATV use is a growing activity in the region, managing ATV use in sensitive areas or awareness among ATV users about peatland conditions could reduce negative impacts and ensure sustainable use to maintain the ecosystem services provided by peatlands.

Les tourbières ombrotrophes, ou bogs sont particulièrement vulnérables à l’augmentation de la déposition atmosphérique d’azote. Cet apport d’un nutriment normalement limitant altère la capacité des tourbières à accumuler le carbone (C), en plus de mener à des changements de leur composition végétale. L’imagerie spectrale est une approche prometteuse puisqu’elle rend possible la détection des espèces végétales et de certaines caractéristiques chimiques des plantes, à distance. Toutefois, l’ampleur des différences spectrales intra- et interespèces n’est pas encore connue. Nous avons évalué la façon dont la chimie, la structure et la signature spectrale des feuilles changent chez Chamaedaphne calyculata, Kalmia angustifolia, Rhododendron groenlandicum et Eriophorum vaginatum, dans trois tourbières du sud du Québec et de l’Ontario, incluant une tourbière où se déroule une expérience de fertilisation à long terme. Nous avons mesuré des changements dans les traits fonctionnels dus aux différences dans la quantité d’azote disponible dans les sites. Toutefois, la déposition atmosphérique d’azote a eu relativement peu d’effet sur les spectres foliaires ; les variations spectrales les plus importantes étaient entre les espèces. En fait, nous avons trouvé que les quatre espèces ont un spectre caractéristique, une signature spectrale permettant leur identification au moyen d’analyses discriminantes des moindres carrés partiels (PLSDA). De plus, nous avons réussi à prédire plusieurs traits fonctionnels (l’azote, le carbone ; et la proportion d’eau et de matière sèche) avec moins de 10 % d’erreur grâce à des régressions des moindres carrés partiels (PLSR) des données spectrales. Notre étude fournit de nouvelles preuves que les variations intraspécifiques, causées en partie par des variations environnementales considérables, sont perceptibles dans les spectres foliaires. Toutefois, les variations intraspécifiques n’affectent pas l’identification des espèces ou la prédiction des traits. Nous démontrons que les spectres foliaires comprennent des informations sur les espèces et leurs traits fonctionnels, confirmant le potentiel de la spectroscopie pour le suivi des tourbières. / Abstract Bogs, as nutrient-poor ecosystems, are particularly sensitive to atmospheric nitrogen (N) deposition. Nitrogen deposition alters bog plant community composition and can limit their ability to sequester carbon (C). Spectroscopy is a promising approach for studying how N deposition affects bogs because of its ability to remotely determine changes in plant species composition in the long term as well as shorter-term changes in foliar chemistry. However, there is limited knowledge on the extent to which bog plants differ in their foliar spectral properties, how N deposition might affect those properties, and whether subtle inter- or intraspecific changes in foliar traits can be spectrally detected. Using an integrating sphere fitted to a field spectrometer, we measured spectral properties of leaves from the four most common vascular plant species (Chamaedaphne calyculata, Kalmia angustifolia, Rhododendron groenlandicum and Eriophorum vaginatum) in three bogs in southern Québec and Ontario, Canada, exposed to different atmospheric N deposition levels, including one subjected to a 18 years N fertilization experiment. We also measured chemical and morphological properties of those leaves. We found detectable intraspecific changes in leaf structural traits and chemistry (namely chlorophyll b and N concentrations) with increasing N deposition and identified spectral regions that helped distinguish the site-specific populations within each species. Most of the variation in leaf spectral, chemical and morphological properties was among species. As such, species had distinct spectral foliar signatures, allowing us to identify them with high accuracy with partial least squares discriminant analyses (PLSDA). Predictions of foliar traits from spectra using partial least squares regression (PLSR) were generally accurate, particularly for the concentrations of N and C, soluble C, leaf water, and dry matter content (<10% RMSEP). However, these multi-species PLSR models were not accurate within species, where the range of values was narrow. To improve the detection of short-term intraspecific changes in functional traits, models should be trained with more species-specific data. Our field study showing clear differences in foliar spectra and traits among species, and some within-species differences due to N deposition, suggest that spectroscopy is a promising approach for assessing long-term vegetation changes in bogs subject to atmospheric pollution.