Lawrence Flanagan

• PhD University of Toronto
• Chair at University of Lethbridge

Wetlands are economically valuable ecosystems, in part because they purify wastewater by retaining and processing nutrients, organic matter (OM), and other pollutants. While natural wetlands are highly productive and sequester large pools of carbon (C), it is unclear whether the C cycle of restored treatment wetlands is functionally consistent with...

Northern peatland stores a large amount of organic soil carbon and is considered to be one of the most significant CH4 sources among wetlands. The default wetland CH4 emission scheme in JULES (land surface model of the UK Earth System model) only takes into account the CH4 emissions from inundated areas in a simple way. However, it is known that th...

Natural and constructed wetlands have been successful in remediating municipal and industrial wastewater effluent before it is discharged to downstream watersheds. There are several wetland ecosystem processes that can contribute to retention or removal of elements input in wastewater, although their relative importance is uncertain and variable am...

Peatlands have acted as net CO2 sinks over millennia, exerting a global climate cooling effect. Rapid warming at northern latitudes, where peatlands are abundant, can disturb their CO2 sink function. Here we show that sensitivity of peatland net CO2 exchange to warming changes in sign and magnitude across seasons, resulting in complex net CO2 sink...

In semiarid regions, the growth and survival of cottonwoods (riparian Populus species) depend on river water supplementing the limited precipitation. Indicators of growth and productivity are needed to assess how altered streamflow regimes on regulated rivers impact cottonwood trees and the riparian forest ecosystems they support. We used satellite...

We compiled hydrogen and oxygen stable isotope compositions (δ²H and δ¹⁸O) of leaf water from multiple biomes to examine variations with environmental drivers. Leaf water δ²H was more closely correlated with δ²H of xylem water or atmospheric vapour, whereas leaf water δ¹⁸O was more closely correlated with air relative humidity. This resulted from t...

In the global methane budget, the largest natural source is attributed to wetlands, which encompass all ecosystems composed of waterlogged or inundated ground, capable of methane production. Among them, northern peatlands that store large amounts of soil organic carbon have been functioning, since the end of the last glaciation period, as long-term...

Rivers and their adjacent riparian forests are intimately linked by the exchange of water, nutrients, and organic matter. Both riparian cottonwood trees and adjacent river sediments host microbial communities including archeal methanogens, supporting methane production and emission to the atmosphere. Here we combine microbial community and in vitro...

In the global methane budget, the largest natural source is attributed to wetlands that encompass all ecosystems composed of waterlogged or inundated ground, capable of methane production. Among them, northern peatlands that store large amounts of soil organic carbon have been functioning, since the end of the last glaciation period, as long-term s...

Forest mortality has been widely observed across the globe during recent episodes of drought and extreme heat events. But the future of forest mortality remains poorly understood. While the direct effects of future climate and elevated CO2 on forest mortality risk have been studied, the role of lateral subsurface water flow has rarely been consider...

Methane emission from trees may partially or completely offset the methane sink in upland soils, the only process that has been regularly included in methane budgets for forest ecosystems. Our objective was to analyze multiple biogeochemical processes that influence the production, oxidation and transport of methane in a riparian cottonwood ecosyst...

Peatlands and forests cover large areas of the boreal biome and are critical for global climate regulation. They also regulate regional climate through heat and water vapour exchange with the atmosphere. Understanding how land-atmosphere interactions in peatlands differ from forests may therefore be crucial for modelling boreal climate system dynam...

The response of evapotranspiration (ET) to warming is of critical importance to the water and carbon cycle of the boreal biome, a mosaic of land cover types dominated by forests and peatlands. The effect of warming-induced vapour pressure deficit (VPD) increases on boreal ET remains poorly understood because peatlands are not specifically represent...

Riparian cottonwood forests in dry regions of western North America do not typically receive sufficient growing season precipitation to completely support their relatively high transpiration requirements. Water used in transpiration by riparian ecosystems must include alluvial groundwater or water stored in the potentially large reservoir of the un...

Within the grassland-dominated landscape of the North American Great Plains, riparian forest ecosystems exist along river floodplains. We compared cumulative evapotranspiration (ET) and ecosystem water-use efficiency (WUE) between a cottonwood forest and a nearby native grassland ecosystem in southern Alberta, using eddy covariance measurements dur...

Episodic precipitation pulses are important for driving biological activity in desert ecosystems. The pattern of precipitation, including the size of rain events and the duration of time between events, can influence ecosystem net CO2 exchange (NEE) by shifting the balance between ecosystem photosynthesis and respiration. Our objective was to measu...

The mechanistic understanding of drought‐induced forest mortality hinges on improved models that incorporate the interactions between plant physiological responses and the spatiotemporal dynamics of water availability. We present a new framework integrating a three‐dimensional groundwater model, Parallel Flow (ParFlow), with a physiologically sophi...

Peatlands store substantial amounts of carbon and are vulnerable to climate change. We present a modified version of the Organising Carbon and Hydrology In Dynamic Ecosystems (ORCHIDEE) land surface model for simulating the hydrology, surface energy, and CO2 fluxes of peatlands on daily to annual timescales. The model includes a separate soil tile...

Water table depth (WTD) effects on net ecosystem CO2 exchange of boreal peatlands are largely mediated by hydrological effects on peat biogeochemistry and the ecophysiology of peatland vegetation. The lack of representation of these effects in carbon models currently limits our predictive capacity for changes in boreal peatland carbon deposits unde...

Peatlands store substantial amount of carbon, are vulnerable to climate change. To predict the fate of carbon stored in peatlands, the complex interactions between water, peat and vegetations need more attention. This study describes a modified version of the ORCHIDEE land surface model for simulating the hydrology, surface energy and CO2 fluxes of...

Diurnal and seasonal changes of δ 13 C and δ 18 O in carbon dioxide measured by eddy covariance over an urban surface The isotopic composition of the greenhouse gas CO 2 can provide valuable information about its sources. For example , linear mixing models have been used to identify the sources of enhanced CO 2 in the urban atmosphere using urban a...

The survival of riparian forests depends on water input from their adjacent rivers. There are multiple, additional demands on river water that threatens to reduce the water supply, prompting the question, how much water must be left flowing within a river to sustain the native riparian ecosystems? To address this, we made eddy covariance measuremen...

Improved predictive capacity of hydrology and surface energy exchange is critical for conserving boreal peatland carbon sequestration under drier and warmer climates. We represented basic processes for water and O2 transport and their effects on ecosystem water, energy, carbon and nutrient cycling in a process-based model ecosys to simulate effects...

Grassland productivity is regulated by both temperature and the amount and timing of precipitation. Future climate change is therefore expected to influence grassland phenology and growth, with consequences for ecosystems and economies. However, the interacting effects of major shifts in temperature and precipitation on grasslands remain poorly und...

In the Great Plains, grassland carbon dynamics differ across broad gradients of precipitation and temperature, yet finer-scale variation in these variables may also affect grassland processes. Despite the importance of grasslands, there is little information on how fine-scale relationships compare between them regionally. We compared grassland C ex...

The light-use efficiency (LUE) model of photosynthesis is widely used to estimate ecosystem photosynthesis and net primary production from remote sensing measurements. The fraction of absorbed photosynthetically active radiation (fAPAR) is a dominant term in this model, and it is fundamentally important for model calculations of ecosystem productiv...

Significance Wetlands are unique ecosystems because they are in general sinks for carbon dioxide and sources of methane. Their climate footprint therefore depends on the relative sign and magnitude of the land–atmosphere exchange of these two major greenhouse gases. This work presents a synthesis of simultaneous measurements of carbon dioxide and m...

Significance Terrestrial gross primary productivity (GPP), the total photosynthetic CO 2 fixation at ecosystem level, fuels all life on land. However, its spatiotemporal variability is poorly understood, because GPP is determined by many processes related to plant phenology and physiological activities. In this study, we find that plant phenologica...

Photosynthesis in moss contributes significantly to carbon gain in northern peatland ecosystems. In turn, these northern peatland ecosystems contain a large fraction of the global soil carbon stock, which has been suggested to be vulnerable to warming and drying associated with climate change. The fate of this vast peatland carbon stock depends on...

Ecosystem phenology plays an important role in carbon exchange processes and can be derived from continuous records of carbon dioxide (CO2) exchange data. In this study we examine the potential use of phenological indices for characterizing cumulative annual CO2 exchange in four contrasting northern peatland ecosystems. We used the approach of Jons...

Measurements of the carbon (δ(13) Cm ) and oxygen (δ(18) Om ) isotope composition of C3 plant tissue provide important insights into controls on water-use efficiency. We investigated the causes of seasonal and inter-annual variability in water-use efficiency in a grassland near Lethbridge, Canada using stable isotope (leaf-scale) and eddy covarianc...

The interacting effects of altered temperature and precipitation are expected to have significant consequences for ecosystem net carbon storage. Here we report the results of an experiment that evaluated the effects of elevated temperature and altered precipitation, alone and in combination, on plant biomass production and soil respiration rates in...

Water table fluctuation is one of the key controls governing peatland carbon balance under current and future climatic conditions. Seasonal and inter-annual variations in water table depths can alter the balance between peatland primary production and respiration and so cause a peatland to change between a sink and a source of carbon. Water table f...

There is a continued need for models to improve consistency and agreement with observations [Friedlingstein et al., 2006], both overall and under more frequent extreme climatic events related to global environmental change such as drought [Trenberth et al., 2007]. Past validation studies of terrestrial biosphere models have focused only on few mode...

Northern peatlands are likely to be important in future carbon cycle-climate feedbacks due to their large carbon pools and vulnerability to hydrological change. Use of non-peatland-specific models could lead to bias in modeling studies of peatland-rich regions. Here, seven ecosystem models were used to simulate CO2fluxes at three wetland sites in C...

Metabolic theory and body size constraints on biomass production and decomposition suggest that differences in the intrinsic potential net ecosystem production (NEP(POT) ) should be small among contrasting C(3) grasslands and therefore unable to explain the wide range in the annual apparent net ecosystem production (NEP(APP) ) reported by previous...

We describe a pragmatic approach for evaluating the spatial representativeness of flux tower measurements based on footprint climatology modeling analyses of land cover and remotely sensed vegetation indices. The approach was applied to the twelve flux sites of the Canadian Carbon Program (CCP) that include grassland, wetland, and temperate and bor...

Accurately simulating gross primary productivity (GPP) in terrestrial ecosystem models is critical because errors in simulated GPP propagate through the model to introduce additional errors in simulated biomass and other fluxes. We evaluated simulated, daily average GPP from 26 models against estimated GPP at 39 eddy covariance flux tower sites acr...

Hydrology is one of the key controls governing peatland carbon balance under current and future climatic conditions. Seasonal variations in soil water content and water table depths can alter the balance between peatland primary production and respiration and so cause a peatland to change between a sink and a source of carbon. Seasonal and interann...

Tree species response to climate change-induced shifts in the hydrological cycle depends on many physiological traits, particularly variation in water relations characteristics. We evaluated differences in shoot water potential, vulnerability of branches to reductions in hydraulic conductivity, and water source use between Pinus contorta Dougl. ex...

The effects of climatic factors and vegetation type on evapotranspiration (E) and water use efficiency (WUE) were analyzed using tower-based eddy-covariance (EC) data for nine mature forest sites, two peatland sites and one grassland site across an east-west continental-scale transect in Canada during the period 2003-2006. The seasonal pattern of E...

The regular monitoring of evapotranspiration from satellites has been limited because of discontinuous temporal coverage, resulting in snapshots at a particular point in space and time. We developed a temporal upscaling scheme using satellite-derived instantaneous estimates of evapotranspiration to produce a daily-sum evapotranspiration averaged ov...

Droughts are among the world's most costly natural disasters and collectively affect more people than any other form of natural disaster. The Canadian Prairies are very susceptible to drought and have experienced this phenomenon many times. However, the recent 1999–2005 Prairie drought was one of the worst meteorological, agricultural and hydrologi...

In this study, reflectance measurements gathered over an alfalfa crop, and matching the scale of the flux tower footprint, were used to develop a LUE model driven entirely from optical measurements. The modeled carbon fluxes accurately track the seasonal dynamics in fluxes and provide a continuous time series enabling a novel approach for gap filli...

Ecosystem models are important tools for diagnosing the carbon cycle and projecting its behavior across space and time. Most assessments of model performance occur at individual temporal scales, but ecosystems respond to drivers at multiple time scales. Spectral methods, such as wavelet analyses, present an alternative approach that enables the ide...

In this study we investigated the causes of annual variability in peak aboveground biomass production, net ecosystem productivity (NEP) and gross ecosystem productivity (GEP) during an 8-year period (1999–2006) in a northern Great Plains grassland near Lethbridge, Alberta, Canada. In particular, we tested for a significant relationship between grow...

The large belowground carbon stocks in northern peatland ecosystems are potentially susceptible to release because of the expected differential responses of photosynthesis and respiration to climate change. This study compared net ecosystem CO2 exchange (NEE) measured using the eddy covariance technique at two peatland sites in northern Alberta, Ca...

Measurements of the stable carbon isotope composition of leaf tissue were made on Piceamariana (Mill.) B.S.P trees from four full-sib families grown on three different field sites at the Petawawa National Forestry Institute, Ontario, Canada. The four families chosen exhibited genetic variation for growth characteristics. Genetic variation was also...

The pattern of 14C assimilate distribution was studied in Aralia nudicaulis L. to determine the extent of physiological integration among individual shoots in a clone. The experiments showed that most of the carbon assimilated by an individual shoot remained within that shoot after 24 h. Most of the carbon exported by a shoot was translocated basip...

Surveys of the spectral photon distribution of light in the understory of eight boreal forest stands in northern Alberta were made during 1984. Two seasonal patterns of change in the red:far-red (R:FR) ratio and in the amount of photosynthetically active radiation (expressed as a percentage of full sun, %PAR) were observed. In stands dominated by b...

Peatland ecosystems have been consistent carbon (C) sinks for millennia, but it has been predicted that exposure to warmer temperatures and drier conditions associated with climate change will shift the balance between ecosystem photosynthesis and respiration providing a positive feedback to atmospheric CO2 concentration. Our main objective was to...

Photosynthetic capacity in boreal coniferous forests varies on a seasonal basis in response to the strong fluctuations in environmental conditions, and this contributes significantly to temporal changes in the concentration and stable isotope composition of atmospheric carbon dioxide. Our objectives in this study were to compare measurements of sea...

Data from tower-based sensors measuring incident and reflected shortwave and photosynthetically active radiation (PAR) are used to calculate a broad-band Normalized Difference Vegetation Index (BBNDVI) for five different high latitude sites: sedge tundra at Barrow, AK; shrub tundra at Ivotuk,AK; mixed tundra at Daring Lake in Northwest Territories;...

This study compares eddy-covariance measurements of carbon dioxide fluxes at six northern temperate and boreal peatland sites in Canada and the northern United States of America, representing both bogs and fens. The two peatland types had opposite responses of gross ecosystem photosynthesis (GEP) and ecosystem respiration (ER) to inter-annual fluct...

Climate models predict rising temperatures and more frequent and prolonged droughts, particularly in the northern hemisphere and in the Canadian Prairies. However, few studies have examined the interannual variation in evapotranspiration (E) of northern terrestrial ecosystems in relation to drought. This study analyses multi-year (1998-2006), eddy-...

We describe an approach for evaluating the representativeness of eddy covariance flux measurements and assessing sensor location bias (SLB) based on footprint modelling and remote sensing. This approach was applied to the 12 main sites of the Fluxnet-Canada Research Network (FCRN)/Canadian Carbon Program (CCP) located along an east-west continental...

Remote sensing studies are affected by the inherently anisotropic nature of reflectance from natural surfaces. The objective of this study was to investigate the effect of anisotropic reflectance on the 970 nm water band index (WBI) for Pleurozium schreberi moss from the Fluxnet Canada Western Peatland site in northern Alberta. A series of hyperspe...

Winter CO2 fluxes represent an important component of the annual carbon budget in northern ecosystems. Understanding winter respiration processes and their responses to climate change is also central to our ability to assess terrestrial carbon cycle and climate feedbacks in the future. The factors influencing the spatial and temporal pattern of win...

Understanding the relationships between climate and carbon exchange by terrestrial ecosystems is critical to predict future levels of atmospheric carbon dioxide because of the potential accelerating effects of positive climate–carbon cycle feedbacks. However, directly observed relationships between climate and terrestrial CO2 exchange with the atmo...

Spectral Network (SpecNet) began as a Working Group in 2003 with the goals of integrating remote sensing with biosphere-atmosphere carbon flux measurements and standardizing field optical sampling methods. SpecNet has evolved into an international network of collaborating sites and investigators, with a particular focus on matching optical sampling...

Winter weather on the Canadian prairies is now warmer and drier than 50 years ago and this has implications for soil water re-charge in montane ecosystems with consequences for tree and ecosystem function. We used measurements of the hydrogen isotope ratio of tree stem water to analyze the use of different water sources (winter snow melt, ground wa...

Continuous half-hourly net CO(2) exchange measurements were made using nine automatic chambers in a treed fen in northern Alberta, Canada from June-October in 2005 and from May-October in 2006. The 2006 growing season was warmer and drier than in 2005. The average chamber respiration rates normalized to 10 degrees C were much higher in 2006 than in...

Many wetland ecosystems such as peatlands and wet tundra hold large amounts of organic carbon (C) in their soils, and are thus important in the terrestrial C cycle. We have synthesized data on the carbon dioxide (CO2) exchange obtained from eddy covariance measurements from 12 wetland sites, covering 1–7 years at each site, across Europe and North...

Eddy covariance measurements of methane (CH4) net flux were made in a boreal fen, typical of the most abundant peatlands in western Canada during May–September 2007. The objectives of this study were to determine: (i) the magnitude of diurnal and seasonal variation in CH4 net flux, (ii) the relationship between the temporally varying flux rates and...

This chapter represents a case study of seasonal and annual variation in above-ground biomass production in a northern temperate grassland during a 9 year period (1998–2006). I describe the relationship between variation in biomass production and the major environmental factor controlling this variation, precipitation inputs. Annual peak biomass pr...

Les plantes ligneuses démontrent en général des caractéristiques d'utilisation de l'eau plus conservatrices que celles des plantes herbacées vivaces et annuelles, y compris des valeurs inférieures de conductance stomatale, de photosynthèse nette et de transpiration, mais une plus grande efficacité photosynthétique d'utilisation de l'eau. Habituelle...

Many wetland ecosystems such as peatlands and wet tundra hold large amounts of organic carbon (C) in their soils, and are thus important in the terrestrial C cycle. We have synthesized eddy covariance data of the carbon dioxide (CO2) exchange from twelve wetland sites across Europe and North America, ranging from ombrotrophic and minerotrophic peat...

We developed and applied an ecosystem-scale model that calculated leaf CO2 assimilation, stomatal conductance, chloroplast CO2 concentration and the carbon isotope composition of carbohydrate formed during photosynthesis separately for sunlit and shaded leaves within multiple canopy layers. The ecosystem photosynthesis model was validated by compar...

Many current models of ecosystem carbon exchange based on remote sensing, such as the MODIS product termed MOD17, still require considerable input from ground based meteorological measurements and look up tables based on vegetation type. Since these data are often not available at the same spatial scale as the remote sensing imagery, they can intro...

We conducted measurements of seasonal variation in net ecosystem methane flux using the eddy covariance technique in a moderately-rich fen in northern Alberta, Canada during May-October 2007 as part of the Canadian Carbon Program (a follow-on program to the Fluxnet-Canada Research Network). Mid-day fluxes increased from near zero in May to a peak o...

A litter decomposition study was established in 16 sites at 7 stations of the Fluxnet Canada Research Network. These sites included paired mature and clearcut forest sites at 5 upland stations (BC, SK, ON, QC, NB) as well as one site at each of two wetland stations (AW, QW) . All sites are instrumented for in situ measurements of soil moisture and...

We conducted measurements of seasonal and inter-annual variation in the carbon isotope composition of ecosystem respired CO2 (deltaR) in aspen, black spruce and jack pine dominated ecosystems in northern Saskatchewan during 2004-2006 as part of the Fluxnet-Canada Research Network. All three sites showed relatively small variation (approximately -26...

We compared the carbon isotope composition of ecosystem-respired CO2 (δ13CR) from 11 forest ecosystems in Canada and the USA and examined differences among forest δ13CR responses to seasonal variations in environmental conditions from May to October 2004. Our experimental approach was based on the assumption that variation in δ13CR is a good proxy...

Moss samples from the Fluxnet-Canada western peatland flux station in the Boreal Region of Alberta were measured in the laboratory to obtain the net photosynthesis rate and chlorophyll fluorescence of the moss under controlled environmental conditions, including the regulation of moss water content, simultaneously with measurements of moss spectral...

[1] The confidence with which we can model water deficit effects on grassland productivity is limited by uncertainty about the mechanisms, stomatal and nonstomatal, by which soil water deficits reduce CO2 uptake. We propose that these reductions can accurately be modeled from a combination of stomatal effects on gaseous CO2 diffusion and nonstomata...

Here we present the within-site, seasonal, and interannual variations of the carbon (δ13C) and nitrogen (δ15N) isotope ratios of leaves, wood, bark and litter from four sites in the Amazon region, Brazil. Samples were collected in Manaus (3° 06′07″ S; 60°01′30″ W), Ji-Paraná (10°53′07″ S; 61°57′06″ W), and Santarém (2°26′35″ S; 54°42′30″ W) with me...

Selection of an appropriate model for respiration (R) is important for accurate gap-filling of CO2 flux data, and for partitioning measurements of net ecosystem exchange (NEE) to respiration and gross ecosystem exchange (GEE). Using cross-validation methods and a version of Akaike's Information Criterion (AIC), we evaluate a wide range of simple re...

Carbon flux models based on light use efficiency (LUE), such as the MOD17 algorithm, have proved difficult to parameterize because of uncertainties in the LUE term, which is usually estimated from meteorological variables available only at large spatial scales. In search of simpler models based entirely on remote-sensing data, we examined direct re...

Northern peatlands are a diverse group of ecosystems varying along a continuum of hydrological, chemical, and vegetation gradients. These ecosystems contain about one third of the global soil carbon pool, but it is uncertain how carbon and water cycling processes and response to climate change differ among peatland types. This study examines midsum...

Grassland ecosystems typically exhibit very large annual fluctuations in above-ground biomass production and net ecosystem productivity (NEP). Eddy covariance flux measurements, plant stable isotope analyses, and canopy spectral reflectance techniques have been applied to study environmental constraints on grassland ecosystem productivity and the a...

Our objective was to compare the carbon isotope composition of respired CO2 (delta13CR) from 11 forest ecosystems in Canada and USA and to examine differences among forests in their response to seasonal variation in photosynthetic photon flux density (PPFD), soil and air temperature, vapor pressure deficit (VPD), precipitation, and soil moisture du...

Our main objective was to test whether the carbon isotope composition of ecosystem respired CO2 varied in response to environmental conditions in a manner consistent with well-known leaf-level studies of photosynthetic 13C discrimination. We developed an ecosystem-scale model that calculated leaf CO2 assimilation, stomatal conductance and chloropla...

The confidence with which we can model water deficit effects on grassland productivity is limited by uncertainty about the mechanisms, stomatal and non-stomatal, by which soil water deficits reduce CO2 uptake. We propose that these reductions can accurately be modelled from a combination of stomatal effects on gaseous CO2 diffusion and non-stomatal...

[1] Carbon flux models based on light use efficiency (LUE), such as the MOD17 algorithm, have proved difficult to parameterize because of uncertainties in the LUE term, which is usually estimated from meteorological variables available only at large spatial scales. In search of simpler models based entirely on remote-sensing data, we examined direc...

Peatlands cover about 21% of the landscape and contain about 80% of the soil carbon stock in western Canada. However, the current rates of carbon accumulation and the environmental controls on ecosystem photosynthesis and respiration in peatland ecosystems are poorly understood. As part of Fluxnet-Canada, we continuously measured net ecosystem carb...

Net ecosystem carbon dioxide exchange was measured in two contrasting peatlands in northern Alberta, Canada using the eddy covariance technique during the growing season (May–October). Sphagnum spp. made up approximately 66% of the total LAI (1.52 m2 m−2) at the poor fen and the total N content of Sphagnum capitula was 7.8 mg g−1 at the peak of the...

The Moderate Resolution Spectroradiometer (MODIS) sensor has provided near real-time estimates of gross primary production (GPP) since March 2000. We compare four years (2000 to 2003) of satellite-based calculations of GPP with tower eddy CO2 flux-based estimates across diverse land cover types and climate regimes. We examine the potential error co...

Photosynthetic gas exchange and the stable isotopic composition of foliage water were measured for a xylem tapping mistletoe, Phoradendron juniperinum, and its host tree, Juniperus osteosperma, growing in southern Utah. The observed isotopic composition of water extracted from foliage was compared to predictions of the Craig-Gordon model of isotopi...

Plantago maritima L. was grown at three levels of salinity, 50, 200, 350 mol m−3 NaCl, and the effects on growth, ion content and photosynthetic capacity were studied. Shoot and root dry weight, leaf production and leaf length were all substantially reduced in plants grown at high salinity. Total leaf area of plants grown at 350 mol m−3 NaCl was on...

The natural abundance of 13C (δ13C) generally increases with decomposition of organic matter. This is contrary to the expected decrease, as lignin is hypothesized to accumulate relative to isotopically heavier cellulose. Our objective was to test the hypothesis that 13C depletion should be observed for gymnosperm logs that typically develop advance...