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The EU Nature Restoration Law (NRL) is critical for the restoration of degraded ecosystems and active afforestation of degraded peatlands has been suggested as a restoration measure under the NRL. Here, we discuss the current state of scientific evidence on the climate mitigation effects of peatlands under forestry. Afforestation of drained peatlands without restoring their hydrology does not fully restore ecosystem functions. Evidence on long-term climate benefits is lacking and it is unclear whether CO2 sequestration of forest on drained peatland can offset the carbon loss from the peat over the long-term. While afforestation may offer short-term gains in certain cases, it compromises the sustainability of peatland carbon storage. Thus, active afforestation of drained peatlands is not a viable option for climate mitigation under the EU Nature Restoration Law and might even impede future rewetting/restoration efforts. Instead, restoring hydrological conditions through rewetting is crucial for effective peatland restoration. [ABSTRACT FROM AUTHOR]

Strip-cutting management has been proposed as an alternative to clear-cuts in drained boreal peatland pine (Pinus sylvestris L.) forests. We explored the hydrological feasibility of strip cutting, that is, under which conditions the post-harvest water table (WT) in peat remains sufficiently deep (here, a WT of −0.35 m during the late growing season) to enable undisturbed tree growth. We approached the question by (1) measuring the WTs in a harvested strip and an adjacent unharvested stand in peatland forests in southern Finland and (2) by simulating the WTs in different strip cut layouts, unharvested peatland, and clear-cut cases using a process-based hydrological model. The measured WTs were, on average, 0.06–0.12 m closer to the peat surface in the harvested strips than in the unharvested stands. The hydrological feasibility of strip cutting increased along with increasing site productivity and improving climate conditions. Strip cutting resulted in the rise in the WTs of adjacent unharvested stands, which can have undesired consequences. Depending on the stand density and strip cut layout, the share of the well-drained area in the harvested strips was slightly larger or even two times larger compared to a complete clear-cut of the forest. Narrow strips (here, 13 m in width) indicated better drainage in the harvested area than wider (20–30 m in width) strips. Even though strip cutting has limited capacity to maintain efficient drainage in the harvested strip on low hydraulic conductivity peat, the increase in the WT was smaller than after clear-cut. [ABSTRACT FROM AUTHOR]

Boreal peatlands are vast carbon (C) stores but also major sources of dissolved organic C (DOC) and nutrients to surface waters. Drainage and forest harvesting accelerates DOC leaching. Continuous cover forestry (CCF) is considered to cause fewer adverse environmental effects. Yet, the effects of CCF on DOC processes are unrecognised. We study DOC production and quality in unharvested, CCF, and clear-cut drained peatland forests and in a non-forested alluvial sedge fen. Parallel replicate peat columns with ground vegetation are collected from the uppermost 50 cm at each site, and the water table (WT) is set to −20 or −40 cm depths on the columns. During the eight-month ex situ incubation experiment, the soil water samples are extracted monthly or bi-monthly. The samples are incubated at 15 °C for multiple 72 h incubation cycles to study pore water quality and biodegradation of DOC. The CO2 production occurs during the first three days. The DOC concentrations and the CO2 release per volume of water are significantly lower in the sedge fen than in the drained peatland forests. The WT has a negligible effect on DOC concentrations and no effect on DOC quality, but the higher WT has generally higher CO2 production per DOC than the lower WT. The results suggest that peat in the drained peatlands is not vulnerable to changes per se but that forest management alters biotic and abiotic factors that control the production, transport, and biodegradation of DOC. [ABSTRACT FROM AUTHOR]

Strip-cutting management has been proposed as an alternative to clear-cuts in drained boreal peatland pine (Pinus sylvestris L.) forests. We explored the hydrological feasibility of strip cutting, that is, under which conditions the post-harvest water table (WT) in peat remains sufficiently deep (here, a WT of −0.35 m during the late growing season) to enable undisturbed tree growth. We approached the question by (1) measuring the WTs in a harvested strip and an adjacent unharvested stand in peatland forests in southern Finland and (2) by simulating the WTs in different strip cut layouts, unharvested peatland, and clear-cut cases using a process-based hydrological model. The measured WTs were, on average, 0.06–0.12 m closer to the peat surface in the harvested strips than in the unharvested stands. The hydrological feasibility of strip cutting increased along with increasing site productivity and improving climate conditions. Strip cutting resulted in the rise in the WTs of adjacent unharvested stands, which can have undesired consequences. Depending on the stand density and strip cut layout, the share of the well-drained area in the harvested strips was slightly larger or even two times larger compared to a complete clear-cut of the forest. Narrow strips (here, 13 m in width) indicated better drainage in the harvested area than wider (20–30 m in width) strips. Even though strip cutting has limited capacity to maintain efficient drainage in the harvested strip on low hydraulic conductivity peat, the increase in the WT was smaller than after clear-cut.

Boreal peatlands are vast carbon (C) stores but also major sources of dissolved organic C (DOC) and nutrients to surface waters. Drainage and forest harvesting accelerates DOC leaching. Continuous cover forestry (CCF) is considered to cause fewer adverse environmental effects. Yet, the effects of CCF on DOC processes are unrecognised. We study DOC production and quality in unharvested, CCF, and clear-cut drained peatland forests and in a non-forested alluvial sedge fen. Parallel replicate peat columns with ground vegetation are collected from the uppermost 50 cm at each site, and the water table (WT) is set to −20 or −40 cm depths on the columns. During the eight-month ex situ incubation experiment, the soil water samples are extracted monthly or bi-monthly. The samples are incubated at 15 °C for multiple 72 h incubation cycles to study pore water quality and biodegradation of DOC. The CO2 production occurs during the first three days. The DOC concentrations and the CO2 release per volume of water are significantly lower in the sedge fen than in the drained peatland forests. The WT has a negligible effect on DOC concentrations and no effect on DOC quality, but the higher WT has generally higher CO2 production per DOC than the lower WT. The results suggest that peat in the drained peatlands is not vulnerable to changes per se but that forest management alters biotic and abiotic factors that control the production, transport, and biodegradation of DOC.

Continuous cover management on peatland forests has gained interest in recent years, in part because the tree biomass with significant evapotranspiration capacity retained in selection cuttings could be used as a tool to optimize the site water table level (WTL) from both tree growth and environmental perspectives. This study reports WTL responses from six field trials established on fertile Norway spruce–dominated drained peatland forests across Finland. At each site, replicates of different intensity selection cuttings (removing 17–74% of the stand basal area) or clear-cut in parallel with intact control stands were established and monitored for the WTL for 2–5 postharvest years. The observed WTL rose after selection cuttings, and the response increased with harvest intensity and depended on the reference WTL; that is, larger responses were found during dry summers or in more southern location. Selection cuttings removing about 50% of the stand basal area raised the WTL typically by 15–40%. Using a process-based ecohydrological model, tested against data from the field trials, we show that the role of tree stand in controlling the WTL clearly decreases along the latitudinal climate gradient in Finland. This suggests that the potential of controlling WTL using selection cuttings is more prominent in southern than in northern Finland. Predictions with future climate (2070–2099) further indicated a general decrease of the WTL and that the importance of the tree stand in controlling the WTL will increase, especially in northern Finland. The results overall thus suggest that selection cuttings can be used as a tool to control the WTL in boreal drained peatland forests, and the potential is likely to increase in future climate.

During most of the 20th century, peatlands in Belarus were regarded primarily as a strategic resource for agriculture and energy. In 1991, the Council of Ministers approved a “Scheme of Sustainable Use and Conservation of Peat Resources until 2010” (the “Scheme until 2010”) which allocated a considerable fraction of the country’s mires to nature conservation. Expiry of that Scheme has prompted its replacement with the “National Strategy for the Conservation and Wise (Sustainable) Use of Peatlands in the Republic of Belarus” (the “Strategy”) supported by a new “Scheme until 2030”. The aim is to meet the requirements for both sustainable development of natural resources within Belarus and international conventions. This article describes the development of the Strategy, which was achieved in conjunction with a detailed appraisal of the current state of peatlands in Belarus. The outcome is that the “Scheme until 2030” allocates almost all of the mires that have so far been confirmed still to be in natural (pristine) condition (684,200 ha or 29 % of the total peatland area) to nature conservation, 19,600 ha (1 %) as a reserve of ‘especially valuable’ peat, 99,100 ha (4 %) for commercial peat extraction, and 1,592,600 ha (66 %) for agriculture and forestry.

Drainage is an essential prerequisite in peatland forest management, which generally, but not always, increases stand growth. Growth response depends on weather conditions, stand and site characteristics, management and biogeochemical processes. We constructed a SUSI-simulator (SUoSImulaattori, in Finnish), which describes hydrology, stand growth and nutrient availability under different management, site types and weather conditions. In the model development and sensitivity analysis, we used water table (WT) and stand growth data from 11 Scots pine stands. The simulator was validated against a larger dataset collected from boreal drained peatlands in Finland. In validation, SUSI was shown to predict WT and stand growth well. Stand growth was mainly limited by inadequate potassium supply, and in Sphagnum peats by low oxygen availability. Model application was demonstrated for ditch network maintenance (DNM) by comparing stand growth with shallow (−0.3 m) and deep ditches (−0.9 m): The growth responses varied between 0.5 and 3.5 m3 ha−1 in five years, which is comparable to experimental results. SUSI can promote sustainable peatland management and help in avoiding unnecessary drainage operations and associated environmental effects, such as increased carbon emissions, peat subsidence, and nutrient leaching. The source code is publicly available, and the modular structure allows model extension to cost–benefit analyses and nutrient export to water courses.

The aim of this paper was to evaluate the link between environmental conditions and the vegetation pattern of mountain peatlands drained for forestry. We assumed that (a) water chemistry and soil properties differ between the investigated peatlands types—from fen to bog, (b) the vegetation pattern is dependent on water chemistry and soil properties, and (c) water chemistry and soil properties play different roles in determining peatland patterning. For our study, five ecologically and topographically diverse forestry‐drained shallow peatlands in Central Sudetes, Poland, were selected. A comparison between the studied peatlands and environmental variables was done by discriminant analysis, whereas vegetation–environmental relationship was analysed by canonical correspondence analysis. Results demonstrated that pH, HCO3−, NO3−, and Ca2+ best explained the variation in water chemistry (approximately 74%), whereas base saturation, pHwater, and plant‐available phosphorus best explained the variation in soil properties. Plant assemblages within the peatlands exhibited three vegetation clusters that did not always correspond to peatland ecological type. The vegetation was mostly affected by water chemistry (explained up to 54% of variation), rather than by soil properties. Vegetation within such ecosystems seems to be a good indicator of differences in water chemistry, caused by differences in bedrock (soligenic fen peatlands) or atmospheric inputs (ombrogenic bogs). Our results will help improve our understanding of vegetation–environment relationships in degraded mountain peatland ecosystems in the temperate climate zone. They might also be useful for proper planning of restoration and monitoring of these ecosystems. [ABSTRACT FROM AUTHOR]

Highlights: • Fertilization of low-productive peatlands increases tree stand carbon sink. • Also organic matter decomposition is increased suggesting soil carbon loss. • Increase in tree stand carbon sink exceeded the increase in soil carbon loss. • Fertilization is climate-cooling on decadal but rarely on centennial time scale. Abstract Drainage of peatlands for forestry often leads to carbon dioxide (CO 2) net emission from soil due to loss of peat. This emission can be compensated for by the increased tree growth. Hovewer, many drained peatlands have low tree growth due to nutrient limitations. Tree growth at these peatlands can be effectively increased by fertilization, but fertilization has been also found to increase decomposition rates. We studied the long-term effect of fertilization of low-productive forestry-drained peatlands on the complete ecosystem greenhouse gas exchange, including both soil and tree component, and accounting for CO 2 , methane and nitrous oxide. Five N-rich study sites (flark fens and a rich fen) and one N-poor ombrotrophic site were established. Fertilization had started at the study sites 16–67 years before our measurements. Fertilization considerably increased tree stand CO 2 sink (+248–1013 g CO 2 m−2 year−1). Decomposition increased on average by 45% (+431 g CO 2 m−2 year−1) and litter production by 38% (+360 g CO 2 m−2 year−1). Thus, on average 84% of the increased decomposition could be attributed to increased litter production and 16% to increased soil CO 2 net emission due to increased loss of peat. Soil CO 2 net emission correlated positively with water table depth and top soil N concentration. Fertilization increased soil CO 2 net emission at the drained flark fens on average by 187 g CO 2 m−2 year−1. At the rich fen, net emission decreased. The N-poor bog exhibited soil CO 2 sink both with and without fertilization. Effects on methane and nitrous oxide emissions were small at most sites. The increase in tree stand CO 2 sink was higher than the increase in soil CO 2 net emission, indicating that fertilization has a climate cooling effect in the decadal time scale. Yet, as the fertilized plots at N-rich sites exhibited soil CO 2 source or zero balance, continuation of fertilization-based forestry over several rotations would lead to progressive loss of ecosystem C. At the N-poor bog, fertilization-based forestry may have a climate-cooling effect also in the centennial time scale. [ABSTRACT FROM AUTHOR]

The three turbulent velocity components, water vapour (H2O), carbon dioxide (CO2), and methane (CH4) concentration fluctuations are measured above a boreal peatland and analyzed using conditional sampling and quadrant analysis. The overarching question to be addressed is to what degree lower-order cumulant expansion methods describe transport efficiency and the relative importance of ejections and sweeps to momentum, CH4, CO2 and H2O fluxes across a range of atmospheric flow regimes. The patchy peatland surface creates distinctly different source and sink distributions for the three scalars in space and time thereby adding to the uniqueness of the set-up. The measured and modelled fractional contributions to the momentum flux show that sweep events dominate over ejections in agreement with prior studies conducted in the roughness sublayer. For scalar fluxes, ejections dominate the turbulent fluxes over sweeps. While ejective motions persist longer for momentum transport, sweeping events persist longer for all three scalars. Third-order cumulant expansions describe many of the results detailed above, and the results are surprising given the highly non-Gaussian distribution of CH4 turbulent fluctuations. Connections between the asymmetric contributions of sweeps and ejections and the flux-transport term arising in scalar turbulent-flux-budget closure are derived and shown to agree reasonably well with measurements. The proposed model derived here is much simpler than prior structural models used to describe laboratory experiments. Implications of such asymmetric contributions on, (i) the usage of the now proliferating relaxed-eddy-accumulation method in turbulent flux measurements, (ii) the constant-flux assumption, and (iii) gradient-diffusion closure models are presented. [ABSTRACT FROM AUTHOR]

One important need in the context of peatland restoration is to gain knowledge of soil organic matter quality and current soil-forming process in degraded peatlands. The aim of this study was to evaluate the impact of long-term drainage on soil transformation processes. In autumn 2012, soil survey and sampling was carried out on five shallow peatlands in the Central Sudeten Mountains (Poland) which had been drained for forestry use in the late 1800s or early 1900s. Four organic soils (Histosols) and one organo-mineral soil (Histic Gleysol) were studied. The surface soil horizons were mainly transformed due to long-term forestry drainage. Increased aeration of these layers had enhanced their content of labile forms of carbon and they were undergoing secondary transformation. Soil transformation was more advanced in fen peatlands than in transitional mire or raised bogs. Only the fens exhibited characteristic evidence of the moorsh-forming process. Further drying of these soils will negatively affect their rewetting potential and significantly reduce the effective application of restoration treatments. In order to reduce organic matter transformation and loss from the investigated peatland areas, their drainage ditches should be blocked. Additionally, some trees should be removed from their central areas to reduce evapotranspiration.

Western Amazonia is known to harbour some of Earth's most diverse forests, but previous floristic analyses have excluded peatland forests which are extensive in northern Peru and are among the most environmentally extreme ecosystems in the lowland tropics. Understanding patterns of tree species diversity in these ecosystems is important both for quantifying beta‐diversity in this region, and for understanding determinants of diversity more generally in tropical forests. Here we explore patterns of tree diversity and composition in two peatland forest types – palm swamps and peatland pole forests – using 26 forest plots distributed over a large area of northern Peru. We place our results in a regional context by making comparisons with three other major forest types: terra firme forests (29 plots), white‐sand forests (23 plots) and seasonally‐flooded forests (11 plots). Peatland forests had extremely low (within‐plot) alpha‐diversity compared with the other forest types that were sampled. In particular, peatland pole forests had the lowest levels of tree diversity yet recorded in Amazonia (20 species per 500 stems, Fisher's alpha 4.57). However, peatland pole forests and palm swamps were compositionally different from each other as well as from other forest types in the region. Few species appeared to be peatland endemics. Instead, peatland forests were largely characterised by a distinctive combination of generalist species and species previously thought to be specialists of other habitats, especially white‐sand forests. We suggest that the transient nature and extreme environmental conditions of Amazonian peatland ecosystems have shaped their current patterns of tree composition and diversity. Despite their low alpha‐diversity, the unique combination of species found in tree communities in Amazonian peatlands augment regional beta‐diversity. This contribution, alongside their extremely high carbon storage capacity and lack of protection at national level, strengthens their status as a conservation priority. [ABSTRACT FROM AUTHOR]

Abstract: Litter decomposition is an important control on carbon accumulation in tropical peatlands. Stoichiometric theory suggests that decomposition is regulated by elemental ratios in litter while the home field advantage (HFA) hypothesis predicts that decomposer communities are adapted to local conditions. To date, the relative importance of these contrasting theories for litter decomposition and therefore the carbon balance of tropical peatlands remain poorly understood. We conducted two in situ litter decomposition experiments in a lowland tropical peatland. The first experiment tested the importance of the stoichiometric theory using a factorial nutrient addition experiment at two sites with contrasting vegetation (Raphia taedigera and Campnosperma panamensis) to assess how nutrient addition affected microbial enzyme activity and litter mass loss at the peat surface and at 50 cm depth. The second experiment tested the importance of HFA by reciprocal translocation of leaf litter from R. taedigera and C. panamensis forests, which differed in both litter chemistry and soil nutrient availability, to separate the influence of litter chemistry and soil/site properties on litter mass loss. The activities of hydrolytic enzymes involved in the decomposition of large plant polymers were stimulated by nitrogen addition only where nitrogen availability was low relative to phosphorus, and were stimulated by phosphorus addition where phosphorus availability was low. The addition of nitrogen, but not phosphorus, increased leaf litter decomposition under waterlogged conditions at 50 cm depth, but not at the peat surface. Decomposition was greatest for autochthonous litter irrespective of site nutrient status, indicating that adaptation of the microbial community to low nutrients can partly overcome nutrient limitation, and suggesting that HFA can influence litter decomposition rates. Synthesis. Our study shows that leaf litter decomposition and the activity of microbial enzymes in tropical peatlands are constrained in part by nutrient availability. However, such nutrient limitation of litter decomposition can be overcome by adaptation of the microbial community. [ABSTRACT FROM AUTHOR]

The investigations were carried out in six small mid-forest peat bogs with active peat-forming processes, all situated in the Lublin region (Eastern Poland). The bogs represented two floristically different types of peatland: raised bogs and transitional mires species composition analysis and specific chemistry analysis (pH, Eh, carbon content, N, P, Mg, Na, Ca, Mn, Fe, dehydrogenase activity and water level) were performed. The plant assotiations/communities of the peat bogs represented three phytosociological classes: Scheuchzerio-Caricetea nigrae, Oxycocco-Sphagnetea , and Vaccinio-Piceetea . The analysis of redox potential measured in the different communities revealed differences in the Eh values between these phytocoenoses ( p < 0.001 ). Assotiations representing Vaccinio uliginosi-Pinetum were found in areas characterised by the highest redox potential. Redox potential values in these communities were significantly higher than the values recorded in bog communities and mosaic associations. Seasonal variability of the redox potential was noted as well. The current research indicates that soil chemical parameters: pH, Eh are closely related with water table level and plant distributions. [ABSTRACT FROM AUTHOR]

Reducing the strain on water bodies caused by sediment loads released after ditch network maintenance (DNM) is addressed in operational peatland forestry by implementing sediment control structures in ditches. This study evaluates computationally alternative sediment control scenarios in a 5.2 ha deep peat site in eastern Finland. Coupled to a distributed hydrological model, peat erosion and transport in the ditches were simulated for the first year after DNM with 15 scenarios consisting of individual structures (e.g., sedimentation ponds) and their combinations. One scenario represented the prevailing conditions with a V-notch weir at the catchment outlet. All scenarios were evaluated against a baseline scenario in which no structures affected the catchment sediment processes. The results suggested that bed erosion can be efficiently prevented with breaks in cleaning and structures ponding water. It was proven less efficient to trap already eroded material with sedimentation ponds and pits. The structures raising ditch water level had limited effects on water table levels in the strips between ditches, plausibly not impairing tree growth. The process-based modeling presented here provided a yet unexplored approach to comprehensively evaluating alternatives for sediment control, which is highly needed to address the gap between existing scientific knowledge and operational peatland forestry practices. [ABSTRACT FROM AUTHOR]

During most of the 20th century, peatlands in Belarus were regarded primarily as a strategic resource for agriculture and energy. In 1991, the Council of Ministers approved a "Scheme of Sustainable Use and Conservation of Peat Resources until 2010" (the "Scheme until 2010") which allocated a considerable fraction of the country's mires to nature conservation. Expiry of that Scheme has prompted its replacement with the "National Strategy for the Conservation and Wise (Sustainable) Use of Peatlands in the Republic of Belarus" (the "Strategy") supported by a new "Scheme until 2030". The aim is to meet the requirements for both sustainable development of natural resources within Belarus and international conventions. This article describes the development of the Strategy, which was achieved in conjunction with a detailed appraisal of the current state of peatlands in Belarus. The outcome is that the "Scheme until 2030" allocates almost all of the mires that have so far been confirmed still to be in natural (pristine) condition (684,200 ha or 29 % of the total peatland area) to nature conservation, 19,600 ha (1 %) as a reserve of 'especially valuable' peat, 99,100 ha (4 %) for commercial peat extraction, and 1,592,600 ha (66 %) for agriculture and forestry. [ABSTRACT FROM AUTHOR]

The current understanding, based on previous studies, is that increased discharge nutrient concentrations from boreal peatlands drained for forestry return to similar levels as those of pristine peatlands within about 20 years after their drainage. As an implicit consequence of this finding, it has been assumed that there are no long-term increasing trends in nutrient exports from these peatlands after the establishment of forestry. We analysed discharge total nitrogen (TN) and phosphorus (TP) concentration data from 54 catchments with undrained pristine peatlands and 34 catchments with drained peatlands using data with considerably longer drainage history than in previous studies. Our results agree with previous studies in that discharge TN and TP concentrations in areas drained 20–30 years ago did not differ much from those in pristine sites. However, we also observed that the TN and TP concentrations were increasing with years since drainage of these catchments. Discharge TN and TP concentrations were over two times higher in areas drained 60 years ago when compared with more recently drained areas. Our results challenge the current perceptions by showing that forestry-drained peatlands may contribute to water eutrophication considerably more than previously estimated. [ABSTRACT FROM AUTHOR]

Drainage can help restore hydrological conditions conducive to the growth of black spruce ( Picea mariana ) seedlings on logged forested peatlands. The impact of drainage was assessed by analysing the variation in stand density at stump height, black spruce seedling annual diameter growth and composition of plant communities on 20 of the oldest operationally drained sites in Quebec’s James Bay region. These sites, each consisting of a drained, post-harvest area and a corresponding undrained, post-harvest control area, were classified into five ecosites based on soil characteristics and plant communities. The ecosites studied varied from those with rich mineral soils covered with a shallow organic layer to very poor, deep, organic soils. Results showed that the growth response of black spruce seedlings following drainage was strongly dependent on the ecosite. Ecosites RE37 and rich RE39 showed a substantial and steady growth response of black spruce to drainage over time. Therefore, drainage caused a significant increase in stand density and growth rate of black spruce seedlings in moderately rich ecosites. In the other ecosites studied, the peat layer was either too thick (poor RE39 and very poor RE39) or too shallow (RE26) for black spruce stand densities and individual stems growth to increase with drainage, compared to those of the control areas. [ABSTRACT FROM AUTHOR]

Peat fires become a yearly tradition, so that necessary precautions are needed in order to minimize the destruction of peatlands. Peatland fires can be detected through hotspots occurrence in the region, but not all hotspots indicate fires. However, hotspots consecutively found in a certain area in the period of two to five days are strong indicators for forest and land fires. This study aims to obtain characteristics of hotspot sequential patterns in peatland using data mining approach. The algorithm used is Sequential pattern Discovery using Equivalent Class (SPADE) that applies a vertical format in sequential pattern mining to extract frequent sequences on dataseis. This study involves spatial data including hotspot data from FIRMS NASA, peatland characteristics from Wetland International to enrich our analysis, and the district border layer to determine the location of hotspot sequences. Data transformation was performed to prepare dataseis before applying SPADE. There are 316 sequences found in Kalimantan and Sumatra in 2014 and 2015 with a minimal of two days occurrences and minimum support of 1%. This study shows that hotspot sequences in Kalimantan 2014 and 2015 are frequently occurred in peatland that has the type of Hemists/Fibrists (60/40) and depth of 400-800 cm. In addition, hotspot sequences in Sumatera 2014 and 2015 are typically occurred in peatland that has the type of Hemists/Saprists (60/40), landuse of swamp forest and depth of 100-200 cm. [ABSTRACT FROM AUTHOR]

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Background and aims: Estimation of root-mediated carbon fluxes in forested peatlands is needed for understanding ecosystem functioning and supporting greenhouse gas inventories. Here, we aim to determine the optimal methodology for utilizing ingrowth cores in estimating annual fine-root production (FRP) and its vertical distribution in trees, shrubs and herbs. Methods: We used 3-year data obtained with modified ingrowth core method and tested two calculation methods: 'ingrowth-dividing' and 'ingrowth-subtracting'. Results: The ingrowth-dividing method combined with a 2-year incubation of ingrowth cores can be used for the 'best estimate' of FRP. The FRP in the nutrient-rich fen forest (561 g m) was more than twice that in the nutrient-poor bog forest (244 g m). Most FRP occurred in the top 20-cm layer (76-82 %). Tree FRP accounted for 71 % of total FRP in the bog and 94 % in the fen forests, respectively, following the above-ground vegetation patterns; however, in fen forest the proportions of spruce and birch in FRP were higher than their proportions in stand basal area. Conclusions: Our methodology may be used to study peatland FRP patterns more widely and will reduce the volume of labour-intensive work, but will benefit from verification with other methods, as is the case in all in situ FRP studies. [ABSTRACT FROM AUTHOR]

Northern peatlands store globally significant amounts of soil carbon that could be released to the atmosphere under drier conditions induced by climate change. We measured forest floor respiration (RFF) at hummocks and hollows in a treed boreal bog in Alberta, Canada and partitioned the flux into aboveground forest floor autotrophic, belowground forest floor autotrophic, belowground tree respiration, and heterotrophic respiration using a series of clipping and trenching experiments. These fluxes were compared to those measured at sites within the same bog where water-table (WT) was drawn down for 2 and 12 years. Experimental WT drawdown significantly increased RFF with greater increases at hummocks than hollows. Greater RFF was largely driven by increased autotrophic respiration driven by increased growth of trees and shrubs in response to drier conditions; heterotrophic respiration accounted for a declining proportion of RFF with time since drainage. Heterotrophic respiration was increased at hollows, suggesting that soil carbon may be lost from these sites in response to climate change induced drying. Overall, although WT drawdown increased RFF, the substantial contribution of autotrophic respiration to RFF suggests that peat carbon stocks are unlikely to be rapidly destabilized by drying conditions. [ABSTRACT FROM AUTHOR]

In the future management and sustainable use of boreal forests, it is crucial to consider the rate and strength of tree responses to an elevated water table and the concurrent oxygen limitations, especially in peatlands. We examined the response dynamics of 7-year-old Scots pine ( Pinus sylvestris L.) seedlings to a 5-week waterlogging (WL) treatment during a growing season in a root lab (dasotron) experiment. WL took place after shoot elongation had ended but while growth of the trunk diameter was still in progress. Trunk sap flow and needle water potential started to decrease immediately after the onset of WL, while the first signs in needle gas exchange - seen as decreases in the potential efficiency of photosystem II, the rates of light-saturated net assimilation and transpiration, and increased needle respiration - were observed after 3 weeks of WL. New needles responded to WL more strongly than the old ones. Drainage with consequent re-oxygenation of the soil caused a further decrease in sap flow. We conclude that through negative feedback on transpiration and net photosynthesis, WL during the growing season is harmful for Scots pine, leading to potential growth losses or even dying of trees within a few weeks of WL. [ABSTRACT FROM AUTHOR]

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The aquatic effects of forestry practices and peat extraction continue to cause serious concerns. The effect mechanisms of peat extraction on water quality and aquatic ecology of the receiving surface waters are well known, but the impacts are often difficult to differentiate from those of forest management. A pairwise temporal sediment study was conducted on two adjacent lakes in Central Finland to study whether the unique effects of peat extraction can be detected in an area of intensive forest drainage. Both lakes are affected by forestry, but the reference lake has no history of peat extraction in its watershed. The deepest parts of the lakes were cored through the lacustrine sediments, and the recent carbon and dry matter sedimentation rates were compared to their site-specific reference values. Recent changes in benthic macroinvertebrates (chironomids) and diatom algae were studied to assess the ecological effects of these practices in the lakes. No significant differences in recent increases in carbon accumulation were found between the peat extraction-impacted lake and the reference lake. The pairwise comparison allowed identification of a regional pattern of impacts that is closely related to the history of land use, particularly forestry, in the region. The approach also allowed identification of the transient signs of peat extraction in the chemical and chironomid records of the impacted lake. The recent changes in chironomids and diatoms suggest eutrophication and deterioration in benthic conditions likely caused by drainage ditch network maintenance activities in the catchments. [ABSTRACT FROM AUTHOR]

Ditch cleaning in drained peatland forests increases sediment loads and degrades water quality in headwater streams and lakes. A better understanding of the processes controlling ditch erosion and sediment transport in such systems is a prerequisite for proper peatland management. In order to relate hydrological observations to key erosion processes in headwater peatlands drained for forestry, a two-year study was conducted in a nested sub-catchment system (treated with ditch cleaning) and at two reference sites. The treated catchment was instrumented for continuous discharge and turbidity monitoring, erosion pin measurements of changes in ditch bed and banks and time-integrated sampling of suspended sediment (SS) composition. The results showed that ditch cleaning clearly increased transient suspended sediment concentrations (SSCs) and suspended sediment yields (SSYs), and resulted in temporary storage of loosely deposited organic sediment in the ditch network. After exhaustion of this sediment storage, subaerial processes and erosion from ditch banks became dominant in producing sediment for transport. Recorded SSCs were higher on the rising limbs of event hydrographs throughout the study period, indicating that SS transport was limited by availability of erosion-prone sediment. A strong positive correlation ( R2 = 0.84, p < 0.001) between rainfall intensity (above a threshold of 1 mm h−1) and average SSC obtained on the rising limb of hydrographs for the sub-catchment showed that soil detachment from ditch banks by raindrop impact can directly increase SSC in runoff. At the main catchment outlet, variation in SSC was best explained ( R2 = 0.67, p < 0.05) by the linear combination of initial discharge (−), peak discharge (+) and the lag time from initial to peak discharge (−). Based on these factors, ditch cleaning slightly increased peak discharges and decreased transit times in the study catchment. The implications of the results for water pollution management in peatland forests are discussed. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Wood ash contains all the essential plant nutrients except nitrogen, and thus supports tree growth especially on peatlands where mineral nutrients often are in short supply. Here we report the effects of wood ash fertilization on the soil microbial community in a boreal drained peatland, characterized by phospholipid fatty acid (PLFA) composition, and more specifically the fungal community, characterized with PCR-DGGE fingerprinting and sequencing methods. We investigated the microbial communities in unfertilized and ash-fertilized sample plots (loose wood ash 5000 or 15 000 kg ha −1 ) 6 years after fertilization. Microbial function measured as heterotrophic basal respiration increased over 30% in the surface peat layer after wood ash fertilization, yet the result was statistically insignificant. The higher amount of wood ash induced a shift in the microbial community in the surface peat layer (0–10 cm) along with an increase in pH. A higher relative proportion of fungal-specific PLFA 18:2ω6 and an increased fungal:bacterial ratio indicated that fungi benefited from the higher amount of wood ash in the topmost layer. Also, the lower amount of wood ash seemed to have stimulated actinobacteria. Our results indicated that higher pH and extra nutrients due to wood ash fertilization promoted the appearance of mycorrhizal and wood-decomposing fungi directly or via increased tree growth. We suggest that wood ash as a fertilizer would be a natural and economical choice to improve the nutrient status of drained peatlands used for forestry since it maintains the positive feedback between fungi and trees. [ABSTRACT FROM AUTHOR]

Sufficiency of potassium (K) is one of the biggest concerns for forestry in boreal peatlands, since the rooting zone stores of K in thick peat soils are generally small and significant proportion of the K in ecosystem is bound in stand biomass. Increased demand for bioenergy may lead to intensified harvesting also in such forests. There is thus an urgent need to study the significance of the nutrients in harvest residues for the next-generation forest productivity. The specific questions in peatland forests are whether the harvest residues are an important source of K to the restock or whether the K in harvest residues is lost by leaching. We quantified K losses from drained peatland forests following management by clear-felling with stem-only harvesting (SOH), whole-tree harvesting (WTH) and whole-tree harvesting plus stump harvesting (WTHS). Calibration period – control area method and mixed modelling approach were used to analyze the ditch-outflow K-concentration and water-borne K-export data from 17 harvested and 5 control catchments in southern and central Finland. K concentrations and runoff were monitored for 1–2 years before and 3–4 years after treatment. Supplementary long-term data from one pair of harvested and non-managed catchments was used to assess the duration of the harvest impact on K export. Mean annual K concentrations in ditch outflow were higher after than before harvesting. The concentrations started to increase during the second or third post-harvest year, reaching the peaks of 1.1–2.2 mg L −1 in WTHS, 0.8–1.7 mg L −1 in WTH, and 1.0–1.9 mg L −1 in SOH. The concentrations correlated positively with the amount of K in the surface peat. In nutrient-poor ombrotrophic sites, the K concentrations were higher for sites with shallower water-table level. Using the supplementary data, the impact of harvesting on K losses was estimated to last for about eight years. The overall estimated K loss was about 28 kg ha −1 from minerotrophic sites, and about 9 kg ha −1 from ombrotrophic sites. There was no significant difference in K losses between the harvest treatments SOH, WTH and WTHS, indicating that the K in harvest residues was largely retained onsite. The role of K losses induced by harvesting in the site K stores in drained peatland forests is discussed. [ABSTRACT FROM AUTHOR]

As part of a broader pattern of recovery after decline called forest transition, tree cover and carbon stocks have increased through agroforestry systems in many parts of Indonesia. The associated tree diversity transition implies that only the most useful parts of local tree flora are promoted. Swampland jelutong, Dyera polyphylla, has been domesticated in peat areas Jambi province, Indonesia. We discuss jelutong domestication in two coastal districts, referring to seven steps in a gradual change from products collected from communal natural forests to specific genotypes managed on private farms. Domestication of D. polyphylla in Jambi was in the initial stages three decades ago, when jelutong latex was directly tapped from the trees in its natural habitat of peat swamp forests. Tapping jelutong latex stopped in 2005 following the national regulation taxing forest products. Some farmers then started jelutong cultivation, motivated by the profitability of trading jelutong latex in the past. Our on-farm study showed that jelutong can be planted in various mixed agroforestry systems, with rubber, coffee or oil palm as dominants. Planted jelutong with good farm management showed diameter growth rates of 1.3 to 1.9 cm year. On-farm trials showed that dolomite as soil ameliorant did not affect diameter growth, but had some effect on height. Jelutong planted between young oil palm had the best performance, while jelutong that was underplanted in mature rubber gardens grew slowly. Slow market revival currently constrains further tree domestication of jelutong. [ABSTRACT FROM AUTHOR]

The aim of this work was to determine the intensity of nitrogen mineralization in forestry drained ombrotrophic peatland soils in the Stołowe Mountains National Park, SW Poland. Additionally discussion about the shallow organic soils classification according to Polish Soil Classification (2011) is presented. For the study three research transects were established on forestry drained ombrotrophic peatlands in the Stołowe Mountains. Each of the transect consisted of four (site A and B) or five (site C) sampling plots. Sampling was conducted in the year 2012. The soil samples for the basic soil properties analysis were sampled in April, whereas undisturbed soil samples were collected in stainless steel rings (100 cm³) every 10 cm in April (spring), July (summer) and October (autumn) to show the seasonal dynamics of nitrogen mineralization. Statistical analysis showed that the content of N-NH4 was mainly determined by actual soil moisture and precipitation rate, whereas the content of N-NO3 was positively correlated with air temperature. Among investigated peatlands the highest concentrations of mineral nitrogen forms was observed in the Długie Mokradło bog, situated on the Skalniak Plateau-summit. Additionally, the results obtained showed that implementation of new subtype: shallow fibric peat soils (in Polish: gleby torfowe fibrowe płytkie) within the type of peat soils (in polish: gleby torfowe) should be considered during developing of the next update of Polish Soil Classification. [ABSTRACT FROM AUTHOR]

The large accumulation of carbon in peatlands arises from slow organic matter decomposition where microorganisms and their enzyme activities play a critical role. However, there is a dearth of studies on the natural patterns of peatland microbial enzyme activity and inhibitory phenolic compounds over seasons, and across a range of depths and biogeochemically different peatland types. We report the spatiotemporal patterns for phenol oxidases, phenolics, and a suite of five key hydrolase enzymes at two depths in two ombrotrophic bogs, mineral poor and rich fens, and a forested basin swamp over the growing season. Results obtained using linear fixed and mixed effect models suggest that phenol oxidase activity varies significantly with temperature and, to a lesser extent pH, leading to a breakdown of inhibitory phenolics and increased hydrolase enzyme activity across all peatland types. Overall, enzyme activity decreased significantly with depth and showed significant variation over the course of the growing season with a minimum in the spring and a maximum in the summer and fall. Enzyme activities were generally greatest in the rich fen and lowest in the forested basin swamp with no significant difference between bogs and poor fens. Site-specific factors such as nutrient availability explain deviations from these patterns. Our results illustrate the widespread but conditional applicability of the enzyme-latch mechanism to peatlands and the vulnerability of the peatland soil organic carbon stock to climate warming. [ABSTRACT FROM AUTHOR]

Boreal peatlands play a crucial role in global carbon cycling, acting as an important carbon reservoir. However, little information is available on how peatland microbial communities are influenced by natural variability or human-induced disturbances. In this study, we have investigated the fungal diversity and community structure of both the organic soil layer and buried wood in boreal forest soils using high-throughput sequencing of the internal transcribed spacer (ITS) region. We have also compared the fungal communities during the primary colonization of wood with those of the surrounding soils. A permutational multivariate analysis of variance (PERMANOVA) confirmed that the community composition significantly differed between soil types (P<0.001) and tree species (P<0.001). The distance-based linear models analysis showed that environmental variables were significantly correlated with community structure (P<0.04). The availability of soil nutrients (Ca [P=0.002], Fe [P=0.003], and P [P=0.003]) within the site was an important factor in the fungal community composition. The species richness in wood was significantly lower than in the corresponding soil (P<0.004). The results of the molecular identification were supplemented by fruiting body surveys. Seven of the genera of Agaricomycotina identified in our surveys were among the top 20 genera observed in pyrosequencing data. Our study is the first, to our knowledge, fungal high-throughput next-generation sequencing study performed on peatlands; it further provides a baseline for the investigation of the dynamics of the fungal community in the boreal peatlands. [ABSTRACT FROM AUTHOR]

Understanding the potential for ecosystem transformation and community change in response to climate variability is central to anticipating future ecological changes, and long-term records provide a primary source of information on these dynamics. We investigated the late Holocene history of upland forest and peatland development at Cranesville Swamp, a peatland located along the West Virginia–Maryland border in the USA. Our primary goal was to determine whether establishment of peatland was triggered by moisture variability, similar to recent developmental models derived from depressional peatlands in glaciated regions. Results indicate that the peatland established at about 1200 cal yr BP, and was associated with a dramatic and persistent change in upland forest composition. Furthermore, timing of these upland and wetland ecological changes corresponded with evidence for multidecadal drought and enhanced moisture variability from nearby tree-ring and speleothem climatic reconstructions. Our results add to a growing body of research highlighting the sensitivity of both peatland development and upland forest communities to transient drought and enhanced moisture variability, and suggest that enhanced moisture variability in the future could increase the probability of similarly abrupt and persistent ecological change, even in humid regions like eastern North America. [ABSTRACT FROM AUTHOR]

Paludification, the accumulation over the mineral soil of poorly decomposed organic matter mainly originating from Sphagnum spp., transforms black spruce ( Picea mariana ) boreal forests into forested peatlands in the prolonged absence of fire, which diminishes forest productivity. High-severity wildfires reset this process by burning the soil organic layer (SOL) and reinitiating forest succession. In contrast, low severity wildfires impact mainly the soil surface and tree layer and do not significantly reduce SOL depth. In the Clay Belt region of eastern Canada, an area prone to paludification, the current forest harvest practice (careful logging around advanced growth [CLAAG]) removes trees but has little impact on the SOL and the understorey vegetation. This is thought to further promote paludification, which consequently reduces forest productivity. Conversely, clearcut (CC) disturbs the SOL and the understorey vegetation, and is thought to favor tree growth. Furthermore, prescribed burning after clearcut (CCPB) is used as a site preparation technique, but may also be used to control paludification as it can burn part of the organic soil layer. Using a retrospective approach, our study examines three hypotheses: compared to CLAAG, CC and CCPB: (1) have positive effects on soil conditions (e.g. decomposition level and pH), (2) reduce Sphagnum spp. and ericaceous shrub cover and (3) result in enhanced black spruce growth. We sampled 22 sites in which we measured SOL characteristics (e.g. depth, decomposition state), understorey vegetation cover and black spruce growth. Compared to CLAAG, CCPB resulted in increased soil decomposition level and higher pH. CCPB also reduced Sphagnum spp. cover but not ericaceous shrub cover. Black spruce growth rate was higher following CCPB than CC, and mean dominant tree height was marginally higher following CCPB than CLAAG and CC. Our results demonstrate that CCPB is beneficial to black spruce growth, presumably through its effects on forest understorey and SOL chemistry. While not similar to a high severity fire, prescribed burning after clearcut in paludified stands on the Clay Belt emulates some wildfire effects such as increasing soil pH. We suggest that unlike CLAAG, prescribed burning after clearcut can restore black spruce stand productivity and should be considered in the context of forest ecosystem management. [ABSTRACT FROM AUTHOR]

Peatland drainage has been an important component of forestry management in the boreal zone and the resulting ditch networks are maintained regularly to sustain forest productivity. In Finland, this is recognized as the most detrimental forestry practice increasing diffuse loads of suspended solids. Alongside forestry management on peatlands, interest in peatland restoration has grown lately. Distributed hydrological modeling has the potential to address these matters by recognizing relevant physical mechanisms and identifying most suitable strategies for mitigating undesired outcomes. This study investigates the utility of such a modeling approach in a drained peatland forest environment. To provide a suitable tool for this purpose, we coupled channel network flow to the three-dimensional distributed hydrological model FLUSH. The resulting model was applied to a 5.2 ha drained peatland forest catchment in Eastern Finland. The model was calibrated and validated using field measurements obtained over frost-free periods of five months. The application showed that distributed modeling can disentangle the importance of spatial factors on local soil moisture conditions, which is significant as peatland drainage aims to control these conditions. In our application, we limited the spatial aspect to the topography and the drainage network, and found that the drainage configuration had a clear effect on the spatial soil moisture patterns but that the effect was less pronounced during the wetter summer. Future applications of distributed modeling in this field comprises investigating the impacts of other spatial factors, modeling channel erosion and solid transport to address strategies for their mitigation, and evaluating restoration schemes. [ABSTRACT FROM AUTHOR]

Forestry harvesting on peats is known to result in significant losses of soil phosphorus (P) to adjacent waters, and the issue is becoming an increasingly serious concern as peatland forest stocks mature and reach harvestable age. One potential solution could be the use of low-cost P recovery techniques based on the chemical precipitation and/or adsorption of the dissolved fraction of soil P, which would otherwise be lost. Such recovery techniques have shown promise in similar applications on mineral soils. However, the interaction of peat with P adsorbing materials can significantly alter their adsorptive characteristics, and it is consequentially not known what materials might be suitable for this application. This study compared the performance of six potential soil amendments (aluminum water treatment residual (Al-WTR), crushed concrete, gypsum, magnesium hydroxide, magnesium oxide, and steel wool) in removing P from aqueous solution in the presence of a typical forest peat soil. Comparison of adsorption isotherms plotted from these batch adsorption studies showed that the observed P adsorption maxima of Al-WTR and steel wool were increased by the presence of peat, from 10.6 mg g −1 and 20.4 mg g −1 , to 11.8 mg g −1 and 52.5 mg g −1 , respectively. In contrast, the observed P adsorption maxima of crushed concrete, gypsum, and magnesium oxide were reduced in the presence of peat, by 44%, 87%, and 37%, respectively. The maximum P adsorption achieved by magnesium hydroxide was increased from 29.8 mg g −1 to 59 mg g −1 at an amendment to peat–solid ratio of 1:4, but decreased from 73.9 mg g −1 to 23.6 mg g −1 at an amendment to peat–solid ratio of 1:10. It was concluded that Al-WTR, in particular, shows considerable promise for use as a soil amendment for P immobilization in a peat environment. [ABSTRACT FROM AUTHOR]

Boreal peatlands in Canada comprise a substantial store of soil organic carbon (peat), and this peat is vulnerable to extensive burning during periods of extended drying. Increased frequency of extreme weather events in boreal regions is expected with future climate change, and the conditions that would support sustained smouldering peat combustion within peatlands may be more common. Organic soils tend to burn by smouldering combustion, a very slow-moving process in fuels such as those found in peatlands. Thus the most extreme conditions for carbon loss to the atmosphere due to the burning of peat likely occur when widespread propagation of flaming combustion leads to widespread initiation of smouldering. To investigate the potential for large-scale, high-intensity fire spread across forested bogs, we examined the fuel conditions in forested bogs necessary to support active crown fire. We measured surface and canopy fine fuels (those available to contribute to the propagating energy flux of the main flaming front) across a postfire chronosequence of forested boreal bog from central Alberta, Canada. We found that fuel load of fine surface material remained relatively constant across the chronosequence and at levels large enough to support crown fire initiation. Black spruce ( Picea mariana (Mill.) B.S.P.) regeneration begins to fill in the crown space with increasing time since disturbance and achieves crown bulk densities similar to black spruce upland forests. We estimated that after about 80 years, the black spruce canopy has developed enough available fuel to support active crown fire on between 10% to 40% of days in a typical fire season in central Alberta, Canada. Broad-scale propagation of high-intensity fire across a peatland when coincident with drought-induced lower moisture in deep peatland layers has the potential to lead to a substantial release of stored terrestrial carbon. [ABSTRACT FROM AUTHOR]

Calibration period and control area method were used to study the impact of forest tree harvesting on the dissolved organic carbon (DOC) export from drained peatland forests using data from 17 harvested and five control catchments. The results indicated highly increased DOC exports; during the first 3 years following harvesting, the average extra export ranged from over 200 kg ha in nutrient-poor ombrotrophic to over 400 kg ha in fertile minerotrophic peatland forest sites. The results indicated that a high iron (Fe) content in peat, as well as a high nitrogen (N) content and a low carbon (C)N ratio, are the site characteristics that contribute to large harvest-induced DOC exports. The effect of Fe is probably caused by the reduction of Fe in previously aerobic peat layers that have undergone harvest-induced water level rise and thus enhanced the DOC export, and the effects of the peat N and CN ratio indicate that the impacts of harvesting on DOC are the greatest from the sites with a high overall microbial activity. The calibration period/control area analysis revealed a high uncertainty in our data, the 95 % confidence intervals for average DOC exports overlapping between the groups with differing site characteristics. Given the uncertainties involved in our data, we conclude that significant changes in water colour and other water characteristics associated with large DOC inputs may be expected, where harvested forests on peatlands cover large proportions of catchments of small lakes and rivers. [ABSTRACT FROM AUTHOR]

Kalimantan peatland spans ∼5.9million ha (∼11% of Kalimantan's total terrestrial land area) as a part ofIndonesian peatlands, covers∼21 million ha, contains∼57.8 Gtof terrestrial carbon. Land cover change of peatland forest results in significant sources CO 2 emissions. Thus, we identified to estimate carbon emissions generated by crop land and ex burnt activities in Kalimantan's peatlands degraded forest.Soil CO 2 respiration was measured under four of the most prominent land cover and annual agricultural crops on 4-5 year post fire (fern, corn, pineapple) and newly burnt areas in West Kalimantan peatlands. Measurements were obtained from Licor 8100 and gatheredby monthly assessments. Among the land cover types showed different meanmonthly CO 2 fluxes.Soil CO 2 respiration on newly burnt peatland, pineapple plantation and fern covered showed the highest and not significantly different among them. Cornsmall-scale plantation soil respired the lowest and significantly different from the other three land covers. Dry vs. rainy month comparisons show huge different (>50%) monthly CO 2 fluxes rate. Each land cover type has distinctive peat environmental factors that significantly affect CO 2 respiration. Theresult indicates that each crop/cover types generate different level site factors, which affect different level of peat CO 2 rates. The regression models of site factors measured for each specific land cover can be applied to obtain better estimate CO 2 respiration rates of degraded peatland and agricultural crop cover types. Moreover, it is able to be applied as a baseline for degraded peatland management and CO 2 emission mitigation. [ABSTRACT FROM AUTHOR]

The capability of L-band radar backscatter to penetrate through the forest canopy is useful for mapping the forest structure, including above ground biomass (AGB) estimation. Recent studies confirmed that the empirical AGB models generated from the L-band radar backscatter can provide favourable estimation results, especially if the data has dual-polarization configuration. Using dual polarimetry SAR data the backscatter signal is more sensitive to forest biomass and forest structure because of tree trunk scattering, thus showing better discriminations of different forest successional stages. These SAR approaches, however, need to be further studied for the application in tropical peatlands ecosystem We aims at estimating forest carbon stocks and stand biophysical properties using combination of multi-temporal and multi-polarizations (quad-polarimetric) L-band SAR data and focuses on tropical peat swamp forest over Kampar Peninsula at Riau Province, Sumatra, Indonesia which is one of the most peat abundant region in the country. Applying radar backscattering (Sigma nought) to model the biomass we found that co-polarizations (HH and VV) band are more sensitive than cross-polarization channels (HV and VH). Individual HH polarization channel from April 2010 explained > 86% of AGB. Whereas VV polarization showed strong correlation coefficients with LAI, tree height, tree diameter and basal area. Surprisingly, polarimetric anisotropy feature from April 2007 SAR data show relatively high correlations with almost all forest biophysical parameters. Polarimetric anisotropy, which explains the ratio between the second and the first dominant scattering mechanism from a target has reduced at some extent the randomness of scattering mechanism, thus improve the predictability of this particular feature in estimating the forest properties. These results may be influenced by local seasonal variations of the forest as well as moisture, but available quad-pol SAR data were unable to show these patterns, since all the SAR data were acquired during the rainy season. The results of multi-regression analysis in predicting above ground biomass shows that ALOS PALSAR data acquired in 2010 has outperformed other time series data. This is probably due to the fact that land cover change in the area from 2007 - 2009 was highly dynamic, converting natural forests into rubber and Acacia plantations, thus SAR data of 2010 which was acquired in between of two field campaigns has provided significant results (F = 40.7, P < 0.005). In general, we found that polarimetric features have improved the models performance in estimating AGB. Surprising results come from single HH polarization band from April 2010 that has a strong correlation with AGB (r = 0.863). Also, HH polarization band of 2009 SAR image resulted in a moderate correlation with AGB (r = 0.440). [ABSTRACT FROM AUTHOR]

Ditch network maintenance in drained peatland forests increases sediment load and causes harmful effects on downstream watercourses. The objective of this study was to identify the immediate erosion processes in the ditch network and quantify the impact of the ditch network maintenance on suspended solids (SS) load at the catchment outlet. Ditch level processes were measured by conducting field campaigns and catchment-level responses were obtained by using the paired catchment approach. Measurements were conducted at two nested catchments in Koivupuro, Eastern Finland, where runoff and turbidity were monitored continuously at the catchment outlets and erosion and deposition were measured in selected ditches with a pin meter, erosion pins and sediment collectors. According to the results, the sediment load was at its highest during the first year after the ditch network maintenance and especially high during the first spring snow-melt period. Pin-meter measurements, sediment-collector data and results of ditch-bed erosion pins showed that the erosion was more severe in the ditch cut into mineral subsoil than in the ditch cut into thick peat. The SS load from the whole Koivupuro catchment during the first year after the ditch network maintenance was, depending on the estimation method, 185 or 250 kg treated-ha −1 a −1 (0.56 or 0.75 kg ditch-m −1 ), while the net erosion within the ditch network was much higher, 6300 kg treated-ha −1 a −1 (19 kg ditch-m −1 ), indicating that suspended solids were deposited before reaching the outlet of the catchment. Compared to the earlier studies which have focused on the catchment-level effects of ditch network maintenance on the SS loads, the current study succeeded in showing erosion processes and their variability within the ditch network and provided information for improving water protection during ditch network maintenance. [ABSTRACT FROM AUTHOR]

We describe here a new species of sphagnicolous testate amoeba found abundantly in the forested part of the Le Cachot peatland (Jura Mountains, Neuchâtel, Switzerland) based on microscopical observations (LM, SEM). The new species, called Nebela gimlii was placed in a phylogenetic tree based on mitochondrial cytochrome oxidase sequences (COI), and branched robustly within the N. collaris complex next to the morphologically similar N. guttata and N. tincta . It is however genetically clearly distinct from these two species, and differs morphologically from them by its smaller size and stouter shape of the shell. This new species completes the phylogeny of the Nebela collaris species complex, with now eight species described, mostly from peatlands and acidic forest litter, and further demonstrates the existence of an unknown diversity within testate amoebae. Improving the taxonomy of testate amoebae in peatlands and clarifying the ecology of newly discovered species should make these organisms even more valuable as bioindicator and for palaeoecological reconstruction. [ABSTRACT FROM AUTHOR]

Subfossil bog oak material is an important palaeo-climate and hydrology proxy for the Holocene. A correct interpretation of the subfossil material in terms of growth and population dynamics requires understanding of the underlying processes. The catastrophic rewetting after dyke-failure of a drained peatland forest in NE-Germany provides a unique natural laboratory to calibrate bog oak growth pattern with a known event. Growth differences among groups of currently vital, damaged and dead oaks in the years before the flooding were used to estimate the adaptation potential in dependence on age, tree-size, competition class and groundwater table. Dendrochronological analysis of growth patterns and wood-anatomical parameters revealed changes in the wood in reaction to sharp hydrological shifts (drainage and rewetting). Group specific chronologies were contrasted against instrumental data to evaluate the influence of climate and hydrology on radial growth of oak. Groundwater table proved to be the overriding factor influencing oak growth at our site, already during times of intensive drainage. Results show an influence of micro-site conditions (elevation above soil-water level) along with a higher chance for slower growing and possibly former suppressed trees to survive the catastrophic rewetting. These trees display a typical ring-pattern with four to five years of depressed growth and a subsequent recovery, characterised by a significant increase in ring-width, especially in the earlywood. Trees that died or were damaged following the rewetting typically show strongly reduced latewood-width before they gradually die-off. Our findings are discussed with regard to the interpretation of subfossil bog oak material and a modified version of release detection analysis is proposed as a tool to sharpen the identification of hydrological shifts in bog oak material. The results of the study can contribute to a better understanding of ecophysiological mechanisms underlying growth reactions (and adaptation potential) of oaks to prevailing high water levels. [ABSTRACT FROM AUTHOR]