Peatlands provide a range of ecosystem services but are sensitive to changes in climate and land-use, and many peatlands globally are degraded. We analyse a large-scale, unique and diverse dataset, ...collected over 15 years, as part of major landscape scale blanket peat restoration projects in the south Pennines, UK. Trajectories of ecosystem change after restoration were assessed by measuring key ecosystem responses including: vegetation cover and indicator species; water table, runoff, and water quality.
The reactions of these metrics vary in their behaviour, both in the timing of first response and the rate of change towards a new stable state. Re-establishment of vegetation is a key driver in rapidly reducing particulate carbon loss and attenuating stormflow, while over time biodiversity is improved by the return of native species, and water tables gradually rise. The phasing of these ecosystem service responses indicates that there are different characteristic timescales for the improvement of peatland functions, driven by both surface and subsurface processes. The rapid establishment of vegetation cover over two years, and its importance in improving a broad range of functions, signify it as a key milestone for reporting project success within typical funding timeframes.
This study supports the adoption of Lime-Fertiliser-Seed-Mulch restoration on eroding blanket peatlands globally. The trajectories developed are important to help guide practitioners of ecological restoration. Better understanding of the dynamics underpinning the slower response times of subsurface hydrological and biogeochemical function is identified as a key knowledge gap. An understanding of the limits of ecosystems recovery is important when target setting for restoration projects, especially where attaining pristine conditions is unachievable.
Display omitted
•Ecosystem services show phased recovery following restoration in eroded peatlands.•Re-vegetation is key to reporting project success over short funding timeframes.•Results support wide-scale adoption of Lime-Seed-Fertiliser-Mulch restoration.
Peatlands are wetland ecosystems with great significance as natural habitats and as major global carbon stores. They have been subject to widespread exploitation and degradation with resulting losses ...in characteristic biota and ecosystem functions such as climate regulation. More recently, large-scale programmes have been established to restore peatland ecosystems and the various services they provide to society. Despite significant progress in peatland science and restoration practice, we lack a process-based understanding of how soil microbiota influence peatland functioning and mediate the resilience and recovery of ecosystem services, to perturbations associated with land use and climate change.
We argue that there is a need to: in the short-term, characterise peatland microbial communities across a range of spatial and temporal scales and develop an improved understanding of the links between peatland habitat, ecological functions and microbial processes; in the medium term, define what a successfully restored ‘target’ peatland microbiome looks like for key carbon cycle related ecosystem services and develop microbial-based monitoring tools for assessing restoration needs; and in the longer term, to use this knowledge to influence restoration practices and assess progress on the trajectory towards ‘intact’ peatland status.
Rapid advances in genetic characterisation of the structure and functions of microbial communities offer the potential for transformative progress in these areas, but the scale and speed of methodological and conceptual advances in studying ecosystem functions is a challenge for peatland scientists. Advances in this area require multidisciplinary collaborations between peatland scientists, data scientists and microbiologists and ultimately, collaboration with the modelling community.
Developing a process-based understanding of the resilience and recovery of peatlands to perturbations, such as climate extremes, fires, and drainage, will be key to meeting climate targets and delivering ecosystem services cost effectively.
•Although microbes are key to peatland function the underpinning processes are unclear.•Microbial characterisation is needed across a range of sites, depths and conditions.•Temporal and spatial changes in microbial communities need to be linked to functions.•Potential to use microbiome as a monitoring tool for peatland restoration progress•Enhancing microbial communities could improve peatland resilience.
The lake sediment phosphorus (P) record at Hatch Mere (Cheshire, UK) is investigated to assess the role of human activity in modifying Holocene landscape P export dynamics, and to develop an approach ...to incorporating this effect into a pre-existing long-term, large-scale landscape model of natural P export. Analysis of the lake sediment record shows that the catchment P yield is low and constant prior to ca. 6000 BP, but then increases up to the present day. This increase occurs in steps that coincide with the Neolithic, Bronze Age and Medieval periods, and the first half of the 20th century, consistent with an anthropogenic cause. Such an interpretation is supported by close correlation of the P export flux with the estimated regional population density. We demonstrate that the effect of human activity on landscape P dynamics can be incorporated into the existing P export model by scaling the soil secondary P leakage rate coefficient to population density. The findings of this study suggest that lake sediment P accumulation rate data may provide a novel method for estimating prehistoric local population density. Additionally, we show that the pre-Neolithic landscape P export was low, and we reject the widely held view that Hatch Mere is naturally eutrophic.
Peatland carbon stores are under widespread anthropogenic pressure, resulting in degradation and carbon loss. This paper presents DO14C (Dissolved Organic Carbon) dates from waters draining two ...eroded blanket peatland catchments in the UK. Both catchments are characterized by severe gully erosion but one additionally has extensive surface erosion on unvegetated surfaces. DO14C values ranged from 104.3 to 88.6 percent modern (present to 976 Before Present). The oldest DOC dates came from the catchment characterized by both gully and surface erosion and are among the oldest reported from waters draining temperate peatlands. Together with peat age‐depth data from across the peatland landscape, the DO14C ages identify where in the peat profile carbon loss is occurring. Source depths were compared with modeled water table data indicating that in the catchment where gully erosion alone dominated, mean water table was a key control on depth of DOC production. In the system exhibiting both gully erosion and surface erosion, DOC ages were younger than expected from the age of surficial peats and measured water tables. This may indicate either that the old organic matter exposed at the surface by erosion is less labile or that there are modifications of hydrological flow pathways. Our data indicate that eroded peatlands are losing carbon from depth, and that erosion form may be a control on carbon loss. Our approach uses point measurements of DO14C to indicate DOC source depths and has the potential to act as an indicator of peatland function in degraded and restored systems.
Plain Language Summary
Peatlands are the largest terrestrial soil carbon store, but are under widespread anthropogenic pressure, resulting in degradation and carbon loss. In this study of UK upland peatlands, we used radiocarbon dating of dissolved organic carbon (DOC) from waters draining eroded peatlands to identify the age of the carbon that has been lost. These dates are among the oldest reported from waters draining temperate peatlands. The dates combined with age‐depth data from across the peatland landscape allowed us to model where in the peat profile the carbon loss was concentrated. We compared these results with water table data and found that in the systems we studied, the type of peatland erosion that the system had experienced was an important factor controlling the age of carbon lost. The close association between radiocarbon age of carbon and water table suggested that radiocarbon dating of DOC might be a useful catchment scale proxy for water table, a direct measurement of the locus of carbon loss from the peat, and an effective measure of the overall “health” of the peatland ecosystem. The approach therefore has potential as a rapid method of assessing stabilization and restoration of intact peatland function.
Key Points
We present old 14C dates from waters draining eroded temperate peats, caused by deep C loss and low water tables in gullied peats
Novel approaches to dissolved organic carbon source identification indicate that water table drawdown and the nature of peat erosion influence loss of old carbon
Our method has potential as a rapid way to indicate peatland function and assess restoration success
Floodplains are dynamic ecosystems that cycle carbon, which is both delivered from upstream catchment sources and produced in-situ. These systems are being increasingly recognised as key environments ...of carbon processing, with the capacity for substantial carbon storage, in addition to acting as hotspots of carbon mineralisation. The balance of storage versus mineralisation is dependent on a number of controls including landscape position and environmental conditions. This study focuses on three headwater floodplains downstream of a highly eroded blanket bog peatland in the Peak District, UK. Previous research has shown that aged organic carbon from peatland sources, has been stored in floodplains in this area, and therefore, we aimed to understand whether allochthonous carbon was being mineralised in this context. We examined sediment cores and analysed the radiocarbon (14C) content of soil-respired CO2, using a partitioning approach to scrutinise the depth and age relations of respiration in the individual floodplains, and patterns of age distributions downstream. Aged organic carbon was released from the upper and mid floodplain sites (14C ages of 682 and 232 years BP, respectively), whereas only modern dates were recorded at the lower site. The geomorphic context and sedimentology supported these results, with the stratigraphy suggesting a dominance of allochthonous deposition at the upper sites, but primarily in-situ soil development at the lower site. There were no trends of radiocarbon age with depth in the individual floodplains, suggesting that floodplain sediments were well mixed and that aged organic matter was being processed both at the surface and at depth in the uppermost sites. An isotope mass balance mixing model indicated the dominance of two sources of CO2; recently fixed C3 organic matter (<10 years old) and CO2 produced by methanogenesis. The results indicate that floodplains in a relatively narrow halo around eroding headwater peatlands, could be important sites of aged carbon turnover originally derived from upstream sources. Reworked carbon does not transfer passively through the system and experiences periods of deposition where it can be subject to microbial action. This is an important consideration in other environments where organic carbon has previously been ‘locked up’ (e.g., permafrost regions) but is now under the threat of release due to climate change.
•Headwater floodplains as hotspots of old carbon turnover decline rapidly downstream.•Floodplains support microbial communities capable of respiring aged organic matter.•Lateral transfers from intact peatlands to floodplains lead to carbon emissions.
Globally, major efforts are being made to restore peatlands to maximise their resilience to anthropogenic climate change, which puts continuous pressure on peatland ecosystems and modifies the ...geography of the environmental envelope that underpins peatland functioning. A probable effect of climate change is reduction in the waterlogged conditions that are key to peatland formation and continued accumulation of carbon (C) in peat. C sequestration in peatlands arises from a delicate imbalance between primary production and decomposition, and microbial processes are potentially pivotal in regulating feedbacks between environmental change and the peatland C cycle. Increased soil temperature, caused by climate warming or disturbance of the natural vegetation cover and drainage, may result in reductions of long-term C storage via changes in microbial community composition and metabolic rates. Moreover, changes in water table depth alter the redox state and hence have broad consequences for microbial functions, including effects on fungal and bacterial communities especially methanogens and methanotrophs. This article is a perspective review of the effects of climate change and ecosystem restoration on peatland microbial communities and the implications for C sequestration and climate regulation. It is authored by peatland scientists, microbial ecologists, land managers and non-governmental organisations who were attendees at a series of three workshops held at The University of Manchester (UK) in 2019–2020. Our review suggests that the increase in methane flux sometimes observed when water tables are restored is predicated on the availability of labile carbon from vegetation and the absence of alternative terminal electron acceptors. Peatland microbial communities respond relatively rapidly to shifts in vegetation induced by climate change and subsequent changes in the quantity and quality of below-ground C substrate inputs. Other consequences of climate change that affect peatland microbial communities and C cycling include alterations in snow cover and permafrost thaw. In the face of rapid climate change, restoration of a resilient microbiome is essential to sustaining the climate regulation functions of peatland systems. Technological developments enabling faster characterisation of microbial communities and functions support progress towards this goal, which will require a strongly interdisciplinary approach.
Classifying sedimentary organics Alderson, Danielle M.; Evans, Martin G.; Rothwell, James J. ...
Progress in physical geography,
06/2016, Letnik:
40, Številka:
3
Journal Article
Recenzirano
Sediments are crucial to the understanding of environmental processes and conditions in a variety of systems. The study of sediments often focuses on quantity, but should involve more emphasis on the ...quality of the organic component, by utilising commonplace techniques employed by other disciplines. We provide a classification scheme that will allow those interested in organic matter quality to decide on appropriate techniques to apply, and discuss a variety of applications of the investigation of organic matter quality in diverse areas of Physical Geography. Firstly, this paper conceptualises organic matter quality by examining how different groups identify with this term, providing a classification scheme that may assist individuals in their exploration of organic matter character. Secondly, it identifies key areas of investigation linked to Physical Geography where research into organic matter quality may provide a necessary or useful component. Finally, it explains and evaluates crucial techniques for characterising organic matter quality.
Classifying sedimentary organics Alderson, Danielle M; Evans, Martin G; Rothwell, James J ...
Progress in physical geography,
06/2016, Letnik:
40, Številka:
3
Journal Article
Recenzirano
Sediments are crucial to the understanding of environmental processes and conditions in a variety of systems. The study of sediments often focuses on quantity, but should involve more emphasis on the ...quality of the organic component, by utilising commonplace techniques employed by other disciplines. We provide a classification scheme that will allow those interested in organic matter quality to decide on appropriate techniques to apply, and discuss a variety of applications of the investigation of organic matter quality in diverse areas of Physical Geography. Firstly, this paper conceptualises organic matter quality by examining how different groups identify with this term, providing a classification scheme that may assist individuals in their exploration of organic matter character. Secondly, it identifies key areas of investigation linked to Physical Geography where research into organic matter quality may provide a necessary or useful component. Finally, it explains and evaluates crucial techniques for characterising organic matter quality.
Identifying and quantifying factors influencing human decision making remains an outstanding challenge, impacting the performance and predictability of social and technological systems. In many ...cases, system failures are traced to human factors including congestion, overload, miscommunication, and delays. Here we report results of a behavioral network science experiment, targeting decision making in a natural disaster. In a controlled laboratory setting, our results quantify several key factors influencing individual evacuation decision making in a controlled laboratory setting. The experiment includes tensions between broadcast and peer-to-peer information, and contrasts the effects of temporal urgency associated with the imminence of the disaster and the effects of limited shelter capacity for evacuees. Based on empirical measurements of the cumulative rate of evacuations as a function of the instantaneous disaster likelihood, we develop a quantitative model for decision making that captures remarkably well the main features of observed collective behavior across many different scenarios. Moreover, this model captures the sensitivity of individual- and population-level decision behaviors to external pressures, and systematic deviations from the model provide meaningful estimates of variability in the collective response. Identification of robust methods for quantifying human decisions in the face of risk has implications for policy in disasters and other threat scenarios, specifically the development and testing of robust strategies for training and control of evacuations that account for human behavior and network topologies.
PDF
