Tim Moore

Tim Moore
McGill University | McGill · Department of Geography

PhD

About

321
Publications
58,820
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23,327
Citations
Additional affiliations
September 1971 - present
McGill University
Position
  • Professor (Full)

Publications

Publications (321)
Article
Full-text available
Northern peatlands are globally important carbon (C) and nitrogen (N) sinks due to slow decomposition rates resulting in long‐term organic matter accumulation. Despite their large N storage, peatlands depend on sources of bio‐available N to sustain their biomass production. Di‐nitrogen (N2) fixation represents an important biological N source in om...
Preprint
Full-text available
The carbon (C) dynamics of northern peatlands are sensitive to hydrological changes owing to ecohydrological feedback. We quantified and evaluated the impact of water level variations in a beaver pond (BP) on the CO2 flux dynamics of an adjacent, raised Sphagnum – shrub-dominated bog in southern Canada. We applied the CoupModel to the Mer Bleue bog...
Article
Full-text available
Peatlands both accumulate carbon and release methane, but their broad range in environmental conditions means that the diversity of microorganisms responsible for carbon cycling is still uncertain. Here we describe a community analysis of methanogenic archaea responsible for methane production in 17 peatlands from 36 to 53 N latitude across the eas...
Article
Peatlands both accumulate carbon and release methane, but their broad range in environmental conditions means that the diversity of microorganisms responsible for carbon cycling is still uncertain. Here we describe a community analysis of methanogenic archaea responsible for methane production in 17 peatlands from 36 to 53 N latitude across the eas...
Preprint
Full-text available
Northern peatlands are globally significant carbon stores, but the sink strength may vary from year-to-year due to variations in environmental and biogeochemical conditions. This variation is mainly brought about by changes in primary production and ecosystem respiration. The processes that relate to variations in autotrophic respiration (AR; respi...
Article
Full-text available
A Correction to this paper has been published: https://doi.org/10.1038/s41558-021-00991-1.
Article
Full-text available
Peatlands represent large terrestrial carbon banks. Given that most peat accumulates in boreal regions, where low temperatures and water saturation preserve organic matter, the existence of peat in (sub)tropical regions remains enigmatic. Here we examined peat and plant chemistry across a latitudinal transect from the Arctic to the tropics. Near-su...
Article
Full-text available
The carbon balance of peatlands is predicted to shift from a sink to a source this century. However, peatland ecosystems are still omitted from the main Earth system models that are used for future climate change projections, and they are not considered in integrated assessment models that are used in impact and mitigation studies. By using evidenc...
Article
Full-text available
Peatlands are important players in climate change–biosphere feedbacks via long-term net carbon (C) accumulation in soil organic matter and as potential net C sources including the potent greenhouse gas methane (CH4). Interactions of climate, site-hydrology, plant community, and groundwater chemical factors influence peatland development and functio...
Article
Rotifers are among the smallest metazoan animals living in lakes, ponds, rivers and in interstitial water within Sphagnum mats. When in sufficient numbers they are capable of regenerating large amounts of nitrogen (N) as NO3 and NH4 and phosphorus (P) as PO4; all of these nutrients are immediately available to bog plants. The ecological role of rot...
Article
Full-text available
Drier conditions caused by drainage for infrastructure development, or associated with global climate warming, may test the resilience of carbon-rich northern peatlands. Feedbacks among biological and hydrological processes maintain the long-term stability of peatlands, but if hydrological thresholds are passed, these feedbacks may be weakened, cau...
Article
Full-text available
Excess reactive nitrogen (N) is linked to a myriad of environmental problems that carry large societal costs. Nitrogen footprint tools can help institutions understand how their direct and indirect activities are associated with N release to the environment through energy use, food, and transportation. However, little is known about how geographic...
Article
Peat accumulation makes nutrient-limited ombrotrophic bogs important carbon sinks, while enhanced atmospheric nitrogen (N) deposition threatens this capacity. Here we show that the stoichiometry of peat and porewater, a control of plant growth and decomposition, has been altered in response to long-term N, phosphorus (P), and potassium (K) fertiliz...
Conference Paper
Full-text available
Peatlands are ecosystems that accumulate carbon (C) over long periods of time. The anoxic conditions created by prevailing water saturation, coupled with vegetation litter slow to decompose, reduces organic matter decay and allows net C accumulation. Open-water pools that cover many boreal and maritime peatlands are, however, net C sources to the a...
Article
Full-text available
Greenhouse Gases in Reservoirs
Article
Carbon (C), hydrogen (H), and oxygen (O) form ~90% by mass of peat, a product of the input of plant tissues and litter and the output of decomposition under aerobic and anaerobic conditions. We examined patterns of these elements, as the O:C and H:C atomic ratios, in over 1,300 peat samples collected from over 400 profiles in Ontario, Canada, repre...
Article
Full-text available
Peatlands represent large terrestrial carbon banks. Given that most peat accumulates in boreal regions, where low temperatures and water saturation preserve organic matter, the existence of peat in (sub)tropical regions remains enigmatic. Here we examined peat and plant chemistry across a latitudinal transect from the Arctic to the tropics. Near-su...
Article
Peatlands are one of the world’s most important ecosystems, storing approximately 30 % of all terrestrial soil carbon as peat. Rotifers living in interstitial water within Sphagnum mats and in pitchers of Sarracenia purpurea are capable of regenerating large amounts of nitrogen (NO3, NH4) and phosphorus (PO4). However, ecological research on rotife...
Poster
Full-text available
Open-water pools are common features in boreal peatlands but their biogeochemistry is poorly understood. Here, we focus on the relationship between vegetation and pool biogeochemistry in two distinct zones of a sub-boreal peatland in Québec, Canada. We assess the summer hydrological and biogeochemical connectivity between peat and pools in a moss-d...
Article
Full-text available
Peatlands play a fundamental role in climate regulation through their long-term accumulation of atmospheric carbon. Despite their resilience, peatlands are vulnerable to climate change. Remote sensing offers the opportunity to better understand these ecosystems at large spatial scales through time. In this study, we estimated water table depth from...
Article
Nutrient availability is an important control on the vegetation distribution, productivity and functioning of peatland ecosystems and we examined spatial and temporal patterns of nutrient availability through ion exchange at Mer Bleue bog, southeast Ontario, Canada. We installed ion exchange probes at 5-15cm for 4weeks and determined nutrient sorpt...
Article
Full-text available
Background and aims We examined changes in soil organic matter arising from conversion of a 45-year old pasture to a 10 yr. old native tree plantation in Panamá, to evaluate the effect of monoculture and mixtures. Methods We intensively sampled the soil 0–10 cm depth in the pasture in 2001 and in 22 plantation plots in 2011, ranging from 5 monocul...
Article
The fruticose lichens Cladina stellaris and Cladina rangiferina, form thick mats that can cover large areas of northern peatlands (above c. 50° latitude), including the extensive peatlands of the Hudson Bay Lowland (HBL) in Canada, where lichens may cover up to 50% of the landscape. Despite the abundance of lichens in northern peatlands, our unders...
Article
Full-text available
Peatlands are globally significant sources of atmospheric methane (CH4). While several studies have examined the effects of nutrient addition on CH4dynamics, there are few long-term peatland fertilization experiments, which are needed to understand the aggregated effects of nutrient deposition on ecosystem functioning. We investigated responses of...
Article
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Litter decomposition, a key process by which recently fixed carbon is lost from ecosystems, is a function of environmental conditions and plant community characteristics. In ice-rich peatlands, permafrost thaw introduces high variability in both abiotic and biotic factors, both of which may affect litter decomposition rates in different ways. Can t...
Article
While considerable attention has been given to the measurement of mercury (Hg) and lead (Pb) concentrations and accumulation in detailed peat cores in central Canada, the geographic distribution and density of sampling are generally limited. Here, we use the Ontario Peatland Inventory to examine broad patterns of Hg and Pb concentration with depth,...
Article
Full-text available
Background and aimsThe litter-bag technique has become common in the estimation of the rates of decomposition, but in many cases the bags are incubated for only a short period, raising the issue of the extent to which short-term incubations represent long-term litter decomposition. We addressed this using 12 years of data from the CIDET study. Meth...
Article
Full-text available
Determining the plant traits that best predict carbon (C) storage is increasingly important as global change drivers will affect plant species composition and ecosystem C cycling. Despite the critical role of peatlands in the global C cycle, trait-flux relationships in peatlands are relatively unknown. We assessed the ability of four non-destructiv...
Poster
Full-text available
Open-water pools are common features in boreal peatlands but their biogeochemistry is poorly known. We studied C, N and P biogeochemistry in open-water pools of a sub-boreal peatland in Québec, Canada. We assessed the relationship between pool physical characteristics and biogeochemistry, and quantified the temporal evolution of C, N and P concentr...
Article
Full-text available
Aims and Methods We measured changes in mass and in carbon (C), nitrogen (N) and phosphorus (P) concentrations and content of surface-placed and buried wood blocks decomposing over 12 years at 21 sites across Canada to evaluate the influence of the environment on C, N, and P dynamics. Results and Conclusions Carbon decomposition over time was best...
Article
We assess the importance of publisher conduct and journal quality in determining the price and cost-effectiveness of journals in geography. Drawing on a database of 136 journals in which geographers publish, we examine the price of journals, publishers' market share, the determinants of journal prices, and the cost-effectiveness of journals. We fin...
Article
Full-text available
Dissolved organic carbon (DOC) plays a key role in the peatland carbon balance and serves numerous ecological and chemical functions including acting as a microbial substrate. In this study, we quantify the concentration, biodegradability, and intrinsic properties of DOC obtained from peat, fresh material, and litter from nine species of ombrotroph...
Article
Full-text available
Ombrotrophic bogs are nutrient-poor systems and important carbon (C) sinks yet there remains a dearth of information on the belowground stoichiometry of C, nitrogen (N), phosphorus (P), and potassium (K), important determinants of substrate quality for microorganisms, in these systems. In this study, we quantified the C, N, P, and K concentrations...
Article
Full-text available
Background and aim Although ombrotrophic peatlands are nutrient deficient, it is not clear to what extent plants will respond to changes in nutrient availability. Methods We examined the changes in foliar stoichiometry and species abundance of four shrub species and moss after a decade of nitrogen (N), phosphorus (P) and potassium (K) fertilization...
Article
To examine where Canadian geographers publish their research, we used data on article publication compiled from the annual Directory of the Canadian Association of Geographers for 1981-82, 1991-92, 2001-02, and 2011-12. We find a very wide range of journals is used; many of them are rarely used. Papers published from 1981 to 2012 increased 3.7-fold...
Article
Full-text available
Previousstudies have shown that atmospheric nitrogen (N) deposition is detrimental to sphagna, which are a group of mosses that are important for carbon cycling in northern peatlands. Little is known about species interactions, such as relative responses of tall mossPolytrichum strictumMenzies ex Brid. and sphagna. We studied the effects of N depos...
Article
The relationship between spectral reflectance and foliar chlorophyll (Chl) and nitrogen (N) was examined for 19 species over a six-month growing period at Mer Bleue, an ombrotrophic bog located near Ottawa, Ontario, Canada. The goal of this study was to model total Chl and N concentration at the landscape-scale from remotely sensed data utilizing a...
Conference Paper
Lichen (Cladina stellaris) can be a dominant vegetation cover on bogs within the extensive peatland landscape of the Hudson Bay Lowlands (HBL), northern Ontario, Canada. The unique characteristics of lichens (growth structure and function as a symbiotic organism), their ability to form thick, dense mats across the HBL bogs, and their increased tole...
Article
Full-text available
Nitrogen (N) pollution of peatlands alters their carbon (C) balances, yet long-term effects and controls are poorly understood. We applied the model PEATBOG to explore impacts of long-term nitrogen (N) fertilization on C cycling in an ombrotrophic bog. Simulations of summer gross ecosystem production (GEP), ecosystem respiration (ER) and net ecosys...
Article
Full-text available
Twelve pig carcasses were buried in single, shallow and deep (30 and 90 cm, respectively) graves at an experimental site near Ottawa, Ontario, Canada, with three shallow and three deep wrapped in black plastic garbage bags. An additional six carcasses were left at the surface to decompose, three of which were bagged. Six reference pits without rema...
Article
Northern peatlands have stored large amounts (~500 Pg) of carbon (C) since the last glaciation. Combined with peat C are nutrients such as nitrogen (N), phosphorus (P), calcium (Ca), magnesium (Mg) and potassium (K), each of which plays an important role in plant production, litter decomposition and the biogeochemical functioning of peatlands. Yet...
Article
Full-text available
Radiative forcing feedbacks from wetlands have been an important component of past climate change and will likely be so in the future, so accurately assessing the carbon (C) and radiative balances of wetlands remains an important research priority. This commentary shows that the paper by Mitsch et al. (Landscape Ecol 28:583–597, 2013) seriously und...
Article
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This study investigated differences in the magnitude and partitioning of the carbon (C) and greenhouse gas (GHG) balances in an age sequence of four white pine (Pinus strobus L.) afforestation stands (7, 20, 35 and 70 years old as of 2009) in southern Ontario, Canada. The 4-year (2004–2008) mean annual carbon dioxide (CO2) exchanges, based on biome...
Article
Full-text available
Here, we present results from the most comprehensive compilation of Holocene peat soil properties with associated carbon and nitrogen accumulation rates for northern peatlands. Our database consists of 268 peat cores from 215 sites located north of 45 degrees N. It encompasses regions within which peat carbon data have only recently become availabl...
Article
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...