Download or read book Carbon Accumulation Rates Over the Holocene in Flow Country Peatlands and the Direct Comparison of Open and Afforested Peatland Carbon Stocks Using Tephrochronology written by Joshua Ratcliffe and published by . This book was released on 2015 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Along with the chronology, carbon content and bulk density data were then used to compare stocks between afforested and open sites. The data highlighted a high variability between sites and thus that a higher level of replication than was possible in this short study will be required to effectively assess the impact of afforestation on carbon stocks. Finally, it has been demonstrated that data generated from this method can be integrated in Bayesian age-depth models to reconstruct paleoecological rates of carbon accumulation, which are almost entirely lacking for UK peatlands. This has been done for one core located within the Flow Country, providing a much needed context in which to view contemporary carbon flux measurements. The potential has been demonstrated for ITRAX scanning to be used for rapid detection of tephra layers in peat in the North of Scotland and other areas where volcanic ash deposition occurs. However, more work and especially a higher level of replication at the site level will be required to assess the impact of afforestation on carbon stocks. This should then be integrated to studies looking at carbon balance using flux-based approaches, and used to inform policy development in the future.

Download or read book Holocene Peatland Carbon Accumulation Ecology and Hydrology in the Canadian James Bay Lowlands written by James Robert Holmquist and published by . This book was released on 2013 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: Northern peatlands contain some of the largest terrestrial stores of organic soil carbon (C) which may grow due to increases in productivity, or decline due to higher decay under projected warming and drought scenarios. However, models of peatland growth lack data on basic peatland history for the remote James Bay Lowlands (JBL) region of Canada, as well as the relationships between climate and productivity, and the history of Holocene precipitation. This dissertation presents C accumulation, vegetative macrofossil, and proxy-climate reconstruction data from eight previously unpublished sites in the JBL, as well as synthesizes currently available data. Peatlands in the JBL initiated lagging the retreat of the Laurentide ice sheet, and the drainage of glacial lakes by an average of 2,900 years. Most of the peatlands studied initiated as mineral rich fens, which transitioned to nutrient poor bogs an average of 3,800 years after they initiated. Over the Holocene they have acted as a sink of CO2, accumulating between 71.5 and 171.2 kgC m−2, with median long-term apparent C accumulation rates (LARCA) ranging from 13.8 to 31.6 gC m−2 yr−1. Peatland C accumulation was variable within and between sites, but was driven by productivity rather than decay during the late-Holocene. The depths of late-Holocene peat deposits correlate positively with growing season length, and photosynthetically active radiation, and were negatively affected by permafrost occurrence. A single site provides evidence for a relatively dry pre-Holocene Thermal Maximum period, and a relatively wet Holocene Thermal Maximum, with a small but positive influence of water table depth on LARCA. Although there was some variation due to site-specific conditions, multiple sites indicate that the warm Medieval Climate Anomaly was a wet period in the JBL, consistent with modern precipitation anomalies, whereas the Little Ice Age was dry. The Little Ice Age may have been locally complex due to precipitation variability, or the formation of permafrost. On the short term, peatland C-stores may grow faster if temperature and seasonality changes occur within their physiological and ecological limitations. However long-term peatland stability in the area will likely be dependent on precipitation, which may fluctuate due to the positions of the Arctic and Pacific fronts, and stochastic interactions between the atmosphere and sea surface temperatures.

Download or read book Peat Growth and Carbon Accumulation Rates During the Holocene in Boreal Mires written by Malin Klarqvist and published by . This book was released on 2001 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Long term Relationships Between Carbon Sequestration Hydrology and Tephra Disturbance in a Northern Peatland Kamchatka Peninsula Russia written by Kristen Marie Tilotta and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Northern peatlands are one of the most important carbon reservoirs, storing one-third to one-half of the world's soil carbon pool and thus changes in their carbon balance have the potential to cause a positive feedback to climate change. While recent studies have made progress in understanding the climatic controls on the global carbon cycle, few have studied the important interaction between landscape disturbance (via volcanic eruptions), carbon accumulation, and peatland hydrology. Kamchatka Peninsula in the Russian Far East provides a unique opportunity to study long-term peatland hydrology and carbon accumulation with respect to the role of disturbance, as the area has been subjected to repeated landscape disturbance by tephra deposition over the last 10,000 years. In this study, I use a 10,000-year-old peatland record from Krutoberegovo, Kamchatka Peninsula (Russian Far East) to examine the interaction between carbon accumulation, peat surface wetness, and landscape disturbance in the form of peat surface burial by volcanic ash (tephra). I specifically ask whether tephra deposition affected the hydrological regime of the peatland, its nutrient status, and its ability to store carbon. To answer this question, I use a suite of palaeoecological and geochemical analyses as follows. First, I use 16 AMS 14C age measurements to create an absolute timescale for peatland development. Second, I use the peatland chronostratigraphy and measurements of peat carbon content to reconstruct the long-term carbon accumulation rates (LORCA). Third, I employ testate amoeba (TA) as a hydrological proxy to reconstruct peat surface wetness over time. Fourth, I reconstruct the nutrient status of the peatland by comparing the carbon to nitrogen ratios (C/N), where higher nitrogen values and lower carbon values are indicative of more nutrient-rich environments and vice versa. My results show that the Krutoberegovo peatland experienced thirty-four different tephra deposition events during the last 10,000 years, of which nine were considered major regional markers, based on their thickness, unique geochemical signatures, and area of dispersal. The carbon sequestration potential of the Krutoberegovo peatland measured as long-term apparent rates of carbon accumulation (LORCA) shows a wide variability over the course of the Holocene ranging from 74.5 g C m-2 yr-1 to 7.91 g C m-2 yr-1, with a substantial decrease in accumulation rates during periods of high tephra loading. Although the mechanisms responsible for this process remain unclear, I hypothesize that changes in carbon sequestration following tephra loading of peat surface could be mediated by changes in microbial activity and wetland vegetation cover. High-resolution analysis of testate amoebae (TA) communities over the course of the Holocene shows a high degree of variability with frequent shifts in taxa dominance. The statistical analysis of testate amoeba taxa in relation to tephra-related environmental variables (total ash content and major eruptions) shows that tephra deposition explains to a large degree the shifts in TA communities. Total ash content explains 77.3% of the taxa variability, while major volcanic eruptions as discrete events explain 6.3%. However, when TA communities are grouped according to their hydrological affinities, tephra deposition does not seem to affect any particular hydrological group suggesting that tephra disturbance does not play a role in peatland hydrology. Analysis of carbon and nitrogen chemistry of the Krutoberegovo peat profile suggest that tephra loading of the peat surface induced a net loss of both carbon and nitrogen. The C/N ratios - a measure of nutrient availability in peatland ecosystems - show a variable but overall increasing trend, which may be related to an autogenic replacement of nutrient rich with nutrient poor wetland plant communities. However, periods with lower or decreasing C/N ratios seem to be associated with high tephra loading, suggesting that tephra deposition may have also played a role.

Download or read book Long term Dynamics and Contemporary Carbon Budget of Northern Peatlands written by Zicheng Yu and published by . This book was released on 2002 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: This publication provides extended abstracts of papers presented at a workshop on forested peatland carbon dynamics. Topics of papers include peat accumulation, carbon flux measurements, peatlands of the western boreal forest and the Mackenzie Valley, the carbon chemistry of peat, the effect of temperature on microbial decomposition, modelling carbon accumulation, peatland hydrology modelling, peatland fire & impacts on carbon dynamics, soil carbon dynamics in the boreal forest, and how peat fits into the Kyoto Protocol.

Download or read book Factors Affecting Holocene Carbon Accumulation in a Peatland in Southern Ontario written by Jennifer Ann Shiller and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Peatlands and Climate Change written by Maria Strack and published by . This book was released on 2008 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: The International Peat Society IPS established a joint IPS Working Group on Peatlands and Climate Change in the end of the year 2005. The Working Group's task was to compile information into a summary of available knowledge to help the IPS and other actors to understand the role of peatlands and peat within the current context of global climate change.

Download or read book Physical Parameters and Accumulation Rates in Peat in Relation to the Climate During the Last 150 Years written by Anders Borgmark and published by . This book was released on 2006 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Global Status of Peatlands and Their Role in Carbon Cycling written by C. P. Immirzi and published by . This book was released on 1992 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Carbon Accumulation and Development of Peatlands Over the Holocene West Siberia Russia written by David Beilman and published by . This book was released on 2006 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: Northern peatlands are storehouses for about one-third of global soil carbon, equivalent to about half of today's atmospheric carbon. The Russian Federation holds the world's greatest share of northern peatlands, and the largest complex is concentrated in the flat, low elevation plain of the West Siberia Lowland (WSL). Recent observed climate warming has been greatest at high latitudes and Arctic environmental change is predicted to continue at accelerated pace. Therefore, the past, present, and future role of peatlands in the global carbon cycle, and in a warmer Arctic, has emerged as an important question. My objective in this dissertation was to investigate the regional-scale development and carbon sequestration and accumulation history of WSL peatlands at more than 70 sites using paleoenvironmental techniques, soil carbon and nitrogen assays, AMS radiocarbon dating, and GIS analysis. Analysis of organic carbon and nitrogen content in peat reveals that values are determined mainly by fossil plant composition. These new data reveal a modest underestimation in previous estimates of the WSL peat carbon pool of 2.9 x 1015g, and the first estimate of the WSL peat nitrogen pool of 2.65 x 1015 g. The remains of fossil plant indicator species in peat profiles together with radiocarbon data show that important transitions to acidic nutrient-poor peatland conditions, which currently dominate today's WSL, have occurred mainly in the last 4000 years of the 12,000-year history of WSL peatlands. The timing of transition events coincides in near-synchonous fashion with inferred wet-climate periods of regional peatland expansion, which suggests that regional climate variation may have affected development. The reconstructed rate of carbon accumulation showed neither consistent increase nor decrease following transition. Carbon accumulation over the last 2000 years reveals considerable variation across the WSL and poor agreement with total carbon accumulation rates over the last 12,000 years. In contrast, net carbon sequestration over the last two millennia has a significant positive and non-linear relationship with modern air temperature. Extrapolation of site trends to the region suggests that about 40% of total WSL peat carbon has accumulated in the last 2000 years. Over recent millennia, the very large peatlands in the southern portion of the region are shown to have been the strongest long-term carbon sinks in the WSL.

Download or read book Peatland Carbon Cycle Responses to Hydrological Change at Time Scales from Years to Centuries written by and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Peatlands cover large areas in boreal and subarctic regions, and contain large stores of carbon in peat. The future of this carbon pool has important implications for the global climate system. Carbon cycling in peatlands depends on plant communities, hydrology, and climate in complex ways, and the responses of the terrestrial carbon cycle to climate change in these regions cannot be fully understood without including wetland processes. I investigated responses of peatland CO2 fluxes to interannual variations in hydrology using CO2 flux measurements from six peatland sites in Canada and the northern United States, including both fens and bogs. Both ecosystem respiration and productivity were negatively correlated with water table fluctuations in fens, and positively correlated with water table fluctuations in bogs. I then analyzed results from an intercomparison study including seven computational models and three peatland field sites. CO2 flux residuals (simulated - observed) were positively correlated with observed water table, and bias was higher at bogs than fens. All models overestimated mean annual peatland productivity and respiration. These results suggest that inability to simulate peatland processes could lead to significant bias in large-scale carbon cycle studies using these types of models. Ecosystem responses over time scales of decades or centuries can contrast with responses over shorter time scales. I used a modified version of the LANDIS-II landscape succession model to investigate carbon cycle responses to drying over multiple century time scales. 100 cm declines in water table led to substantial biomass accumulation, which drove increases in total ecosystem carbon over the first 100 years. However, over longer time scales of 200-400 years, peatlands had a negative carbon balance due to continued soil carbon loss. For 40 cm water tabled declines, peatland carbon balance was dominated by soil carbon loss, and the result was a net loss of total carbon. These results suggest that climatic changes leading to drying of peatlands could result in negative feedbacks to climate change over century time scales. However, a large part of that response is likely transient, and could come at the expense of other important ecosystem services.

Download or read book ELUCIDATING PEATLAND DISTURBANCE ECOLOGY AND CARBON DYNAMICS THROUGH THE LENS OF SOIL USING INFRARED SPECTROMETRY written by and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract : We sought to quantify the fire regimes of peatlands in the hemi-boreal zone of North America, and to understand the qualities of their peat. We used infrared spectrometry to accomplish both goals by gathering spectral information about the organic matter in each sample. We used a series of mixtures of natural peat and natural peat charcoal to isolate the spectral components associated with charcoal concentration. We built a multiple linear regression model which predicts the charcoal concentration in peat samples. We validated our data using nuclear magnetic resonance spectrometry. As a result, we can accurately predict the charcoal concentration of peat samples using only their infrared spectra. Applying this method, we analyzed the charcoal concentration throughout the peat profile in 29 sites in the hemi-boreal region of North America. These sites fell into four peatland ecotypes common in the hemi-boreal region, three types of poor fens, differing by tree cover, and forested rich fens. We found that the poor fen ecotypes had a mean fire return interval of 480 years, while the forested rich fens usually had no evidence of fire. We also found that fire frequency was negatively correlated with carbon accumulation in the poor fen ecotypes. These findings indicate that fire is a normal part of poor fen ecosystems but is rare in forested rich fens. Significant changes to these norms could have deleterious consequences for these ecosystems. We also performed analyses to compare the peat quality of these same ecotypes to one another. Peat quality refers to molecular lability. We were able to consider peat quality throughout each core. We identified that forested peatlands had more consistent, lower peat quality than open fens, which had high quality surface peat that declined in quality rapidly. Overall open poor fens had the highest peat quality, followed by forested poor fens, and finally forested rich fens. This implies that open poor fens are more vulnerable to both short- and long-term disturbances to temperature or water levels. Our research contributes knowledge that equips ecologists, managers, and policy makers to better understand, plan for, and conserve peatlands in our changing world.

Download or read book Holocene Carbon Dynamics in the Patterned Peatlands of the Hudson Bay Lowland Canada written by Maara Susanna Packalen and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Late Quaternary Evolution and Carbon Cycling of Tropical Peatlands in Equatorial Southeast Asia written by and published by . This book was released on 2015 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Quantifying Carbon Accumulation and Loss in Afforested Peatlands written by Thomas Joseph Sloan and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Paleoecological and Carbon Accumulation Dynamics of a Fen Peatland in the Hudson Bay Lowlands Northern Ontario from the Mid Holocene to Present written by Benjamin Cody O'Reilly and published by . This book was released on 2011 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pollen assemblages, peat humification and carbon:nitrogen stratigraphy were examined at high resolution in a core from a fen peatland in the Hudson Bay Lowlands, Northern Ontario, to interpret the factors that drive long-term peatland dynamics. Subtle changes in the vegetation community are evident over the record, suggesting both allogenic and autogenic influences, but a fen community appears to have been resilient to external perturbations including isostatic rebound and hydroclimatic changes between 6400 and 100 years BP. Paleoclimatic reconstructions from the fossil pollen assemblages indicate that precipitation increased 3000 years BP at the end of the Holocene Thermal Maximum, and that carbon accumulation in the fen was controlled more by effective surface moisture (precipitation) than by temperature. The pollen record suggests changes over the past century, including increases in shrub Betula, Alnus, Ambrosia, and Cyperaceae and a decrease in Sphagnum spores, consistent with the observed Pan-Arctic shrub increase.

Download or read book Carbon Gas Exchange Primary Production and Litter Decomposition of a Restored Fen on a Former Oil Well pad written by Alexandra Engering and published by . This book was released on 2018 with total page 75 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over 500,000 oil and gas wells have been drilled in Alberta. Recently updated peatland restoration criteria for well-pads creates incentive for peatland restoration, but little is known about functional outcomes of restoration methods. A valued primary function of peatlands is slower decomposition than production rates resulting in peat and carbon accumulation and net neutral or negative greenhouse gas balance. Three restoration techniques on an abandoned well-pad near Peace River, Alberta were measured for carbon dioxide (CO2) and methane (CH4) emissions during three growing seasons in 2014-2016 (May-Sept, inclusive), 2-4 years post-restoration. Net primary production (NPP), biomass and decay rates were also measured in the fourth year post-restoration. The peat replacement treatments (PRT) and restoration methods included burying the mineral-pad layer underneath the peat layer (clay), burying the mineral layers with some mixing with peat (mixed), and removing the mineral fill layer completely (peat). Seasonal measurements showed some variation between PRTs from year to year for mean gross ecosystem production and ecosystem respiration, while net ecosystem exchange and CH4 fluxes were similar between all PRTs in all years, water table position (WT), soil temperature and vegetation cover explained variation in CO2 exchange, while WT explained some variation in CH4 flux. All PRTs increasingly developed peatland vegetation cover by the third year and had CO2 and CH4 fluxes comparable to the reference sites, despite having significantly different WT position to reference sites. It is likely, however that the reference results were non-representative of the ecosystem level as the similarity in CO2 fluxes would likely not exist if not for the absence of tree photosynthesis captured in plot scale understory CO2 measurements. Decomposition, biomass and NPP also did not differ significantly between PRTs. When compared to natural sites, NPP and biomass, were lower on the restoration site, likely due to the lack of tree establishment to date. Water table and soil temperature did not explain variation in NPP, or decomposition rates on site; however, ion supply rates (Al, Ca, Cu, Fe, K, Mg, Mn, NO2, NH4, P, S, Zn) were correlated to both in some cases. Overall, it is likely that the remnant mineral layer on the site altered peat chemistry, which was seen in abnormally high base cation supply rates. The high ionic availability combined with significantly shallower WT may explain greater decomposition rates compared to reference sites. It is expected that carbon cycling is not restored to that of natural peatlands, as supported by NPP and decay rates different from literature, as well as the drastically different site chemistry. All PRTs are recommended for future restorations as they do show promise for restoring peatland ecosystem functions, however, more research is needed to assess differences in PRTs carbon cycling and peat accumulation in restored peatland. Longer term restoration research should be continued until similar rates are found as on natural peatlands. Future research should involve single PRTs per well-pad for CO2, CH4, litter decomposition and production rates and incorporate the overstory carbon gas exchange of treed natural references.