Pub Date : 2020-02-16DOI: 10.19189/MAP.2019.OMB.STA.1767
W. Liu, A. Grootjans, H. Everts, C. Fritz, N. D. Vries
Rewetting can effectively reduce greenhouse gas (GHG) emissions from drained peatlands. Reliable emissions estimation approaches are needed for accounting of such reductions and for evaluating the potential in terms of carbon credits. Annual mean water level and vegetation are reliable and widely used proxies for emissions estimation. However, indications of water level based on plant species (e.g. Ellenberg Indicator Values) are qualitative with large variances, and there are insufficient high-quality flux measurement data to support the direct use of vegetation as a proxy for GHG fluxes. Here we combine vegetation and water level proxies to estimate emissions, by using bioindication of vegetation communities for water level together with the linear correlation between annual mean water level and GHG fluxes. This approach is demonstrated in the Drentsche Aa brook valley in The Netherlands, where peatlands were rewetted to restore rich fen vegetation. Biodiversity of the landscape was monitored by repeated vegetation mapping before and after rewetting, which enables the estimation of emissions reduction as a co-benefit. Mean annual water level values are assigned to mapped vegetation types using existing data on water level dynamics from measurements on corresponding plant communities. GHG emissions are estimated using linear regression models of gas fluxes against mean annual water levels. This approach provides spatially explicit and quantitative estimation of mean annual water levels and GHG fluxes. When combined with information on spatial patterns and variances, the resulting estimations can promote recognition of the carbon co-benefits of biodiversity restoration while facilitating more site-specific optimisation of management practices.
重新湿润可以有效地减少泥炭地的温室气体排放。需要可靠的排放量估计方法来核算这种减排并评估碳信用的潜力。年平均水位和植被是排放估算的可靠且广泛使用的指标。然而，基于植物物种的水位指示（如艾伦伯格指示值）是定性的，差异很大，并且没有足够的高质量通量测量数据来支持直接使用植被作为温室气体通量的代表。在这里，我们将植被和水位指标结合起来，通过使用植被群落的水位生物指示以及年平均水位和GHG通量之间的线性相关性来估计排放量。这种方法在荷兰的Drentsche Aa brook山谷得到了证明，那里的泥炭地被重新湿润，以恢复丰富的沼泽植被。通过在重新湿润前后反复绘制植被图来监测景观的生物多样性，这使得能够估计减排是一项共同利益。使用相应植物群落测量的水位动态现有数据，将年平均水位值分配给绘制的植被类型。温室气体排放量是使用气体通量与年平均水位的线性回归模型估计的。这种方法提供了对年平均水位和温室气体通量的空间显式和定量估计。当与空间模式和方差信息相结合时，由此产生的估计可以促进对生物多样性恢复的碳共益的认识，同时促进管理实践的更具体的优化。
{"title":"Estimation of greenhouse gas emission reductions based on vegetation changes after rewetting in Drentsche Aa brook valley","authors":"W. Liu, A. Grootjans, H. Everts, C. Fritz, N. D. Vries","doi":"10.19189/MAP.2019.OMB.STA.1767","DOIUrl":"https://doi.org/10.19189/MAP.2019.OMB.STA.1767","url":null,"abstract":"Rewetting can effectively reduce greenhouse gas (GHG) emissions from drained peatlands. Reliable emissions estimation approaches are needed for accounting of such reductions and for evaluating the potential in terms of carbon credits. Annual mean water level and vegetation are reliable and widely used proxies for emissions estimation. However, indications of water level based on plant species (e.g. Ellenberg Indicator Values) are qualitative with large variances, and there are insufficient high-quality flux measurement data to support the direct use of vegetation as a proxy for GHG fluxes. Here we combine vegetation and water level proxies to estimate emissions, by using bioindication of vegetation communities for water level together with the linear correlation between annual mean water level and GHG fluxes. This approach is demonstrated in the Drentsche Aa brook valley in The Netherlands, where peatlands were rewetted to restore rich fen vegetation. Biodiversity of the landscape was monitored by repeated vegetation mapping before and after rewetting, which enables the estimation of emissions reduction as a co-benefit. Mean annual water level values are assigned to mapped vegetation types using existing data on water level dynamics from measurements on corresponding plant communities. GHG emissions are estimated using linear regression models of gas fluxes against mean annual water levels. This approach provides spatially explicit and quantitative estimation of mean annual water levels and GHG fluxes. When combined with information on spatial patterns and variances, the resulting estimations can promote recognition of the carbon co-benefits of biodiversity restoration while facilitating more site-specific optimisation of management practices.","PeriodicalId":48721,"journal":{"name":"Mires and Peat","volume":"26 1","pages":"02"},"PeriodicalIF":1.2,"publicationDate":"2020-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42950002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.19189/MAP.2019.JSP.STA.1789
S. Hafdhi, S. Duchesne, A. St‐Hilaire
Three sedimentation basins on two different extracted peatlands were studied to determine their Trapping Efficiency (TE) using two different methods. First, TE was calculated using sediment loads estimated from turbidity measurements upstream and downstream of the basins. The second method was based on hydraulic modelling and a simplified sediment deposition model. For the first studied basin (controlled by a weir at its downstream end) TE was estimated with the second method at 85.9 % and 55.6 % for lower and higher flows, respectively. In the second peatland the studied basins were in series, there was a geotextile curtain in the middle of each basin and a weir or a double pipe culvert at the outlet. For these two basins in series, TE was estimated at 80 % for lower flows and at 34.3 % for higher flows. A hydraulic model was calibrated for the studied basins and applied to estimate the TE of different basin configurations. The results show that the role of the geotextile curtain is important in the case of short basins and for intense rainfall events. The double pipe culvert did not have a significant effect on TE, unlike the presence of a weir at the outlet, which is required to maintain high TE.
{"title":"Hydraulic modelling for assessment of the performance of sedimentation basins downstream from extracted peatlands.","authors":"S. Hafdhi, S. Duchesne, A. St‐Hilaire","doi":"10.19189/MAP.2019.JSP.STA.1789","DOIUrl":"https://doi.org/10.19189/MAP.2019.JSP.STA.1789","url":null,"abstract":"Three sedimentation basins on two different extracted peatlands were studied to determine their Trapping Efficiency (TE) using two different methods. First, TE was calculated using sediment loads estimated from turbidity measurements upstream and downstream of the basins. The second method was based on hydraulic modelling and a simplified sediment deposition model. For the first studied basin (controlled by a weir at its downstream end) TE was estimated with the second method at 85.9 % and 55.6 % for lower and higher flows, respectively. In the second peatland the studied basins were in series, there was a geotextile curtain in the middle of each basin and a weir or a double pipe culvert at the outlet. For these two basins in series, TE was estimated at 80 % for lower flows and at 34.3 % for higher flows. A hydraulic model was calibrated for the studied basins and applied to estimate the TE of different basin configurations. The results show that the role of the geotextile curtain is important in the case of short basins and for intense rainfall events. The double pipe culvert did not have a significant effect on TE, unlike the presence of a weir at the outlet, which is required to maintain high TE.","PeriodicalId":48721,"journal":{"name":"Mires and Peat","volume":"26 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67989615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.19189/MAP.2018.OMB.388
I. Korpela, R. Haapanen, A. Korrensalo, E. Tuittila, T. Vesala
Boreal bogs are important stores and sinks of atmospheric carbon whose surfaces are characterised by vegetation microforms. Efficient methods for monitoring their vegetation are needed because changes in vegetation composition lead to alteration in their function such as carbon gas exchange with the atmosphere. We investigated how airborne image and waveform-recording LiDAR data can be used for 3D mapping of microforms in an open bog which is a mosaic of pools, hummocks with a few stunted pines, hollows, intermediate surfaces and mud-bottom hollows. The proposed method operates on the bog surface, which is reconstructed using LiDAR. The vegetation was classified at 20 cm resolution. We hypothesised that LiDAR data describe surface topography, moisture and the presence and depth of field-layer vegetation and surface roughness; while multiple images capture the colours and texture of the vegetation, which are influenced by directional reflectance effects. We conclude that geometric LiDAR features are efficient predictors of microforms. LiDAR intensity and echo width were specific to moisture and surface roughness, respectively. Directional reflectance constituted 4–34 % of the variance in images and its form was linked to the presence of the field layer. Microform-specific directional reflectance patterns were deemed to be of marginal value in enhancing the classification, and RGB image features were inferior to LiDAR variables. Sensor fusion is an attractive option for fine-scale mapping of these habitats. We discuss the task and propose options for improving the methodology.
{"title":"Fine-resolution mapping of microforms of a boreal bog using aerial images and waveform-recording LiDAR","authors":"I. Korpela, R. Haapanen, A. Korrensalo, E. Tuittila, T. Vesala","doi":"10.19189/MAP.2018.OMB.388","DOIUrl":"https://doi.org/10.19189/MAP.2018.OMB.388","url":null,"abstract":"Boreal bogs are important stores and sinks of atmospheric carbon whose surfaces are characterised by vegetation microforms. Efficient methods for monitoring their vegetation are needed because changes in vegetation composition lead to alteration in their function such as carbon gas exchange with the atmosphere. We investigated how airborne image and waveform-recording LiDAR data can be used for 3D mapping of microforms in an open bog which is a mosaic of pools, hummocks with a few stunted pines, hollows, intermediate surfaces and mud-bottom hollows. The proposed method operates on the bog surface, which is reconstructed using LiDAR. The vegetation was classified at 20 cm resolution. We hypothesised that LiDAR data describe surface topography, moisture and the presence and depth of field-layer vegetation and surface roughness; while multiple images capture the colours and texture of the vegetation, which are influenced by directional reflectance effects. We conclude that geometric LiDAR features are efficient predictors of microforms. LiDAR intensity and echo width were specific to moisture and surface roughness, respectively. Directional reflectance constituted 4–34 % of the variance in images and its form was linked to the presence of the field layer. Microform-specific directional reflectance patterns were deemed to be of marginal value in enhancing the classification, and RGB image features were inferior to LiDAR variables. Sensor fusion is an attractive option for fine-scale mapping of these habitats. We discuss the task and propose options for improving the methodology.","PeriodicalId":48721,"journal":{"name":"Mires and Peat","volume":"26 1","pages":"03"},"PeriodicalIF":1.2,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67989293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.19189/MAP.2019.OMB.STA.1896
S. Ghadr, A. Assadi-Langroudi, Ching Hung
Colloidal nanosilica hydrosols are electrochemically stabilised polymerised amorphous silica in low viscosity suspensions. They have no known adverse impact on soil health and ecosystem service functions, thereby having a scope for use in groundworks as an alternative low-viscose stabilising material. Six grades of colloidal nanosilica are synthesised through an in-house procedure and introduced to a natural peat soil. The peak and residual compressive strength of compacted and modified soils are measured immediately after treatment and in four strain levels post treatment. Findings suggest that, despite the direct correlation between the nanosilica content and compressive strength, an increase in nanosilica content does not necessarily offer stability at larger strains. This is a major limitation. The particle-level kinematics in modified peat is discussed to gain a new insight into the role played by silica flocs on the build-up of macro-mechanical quantities such as peak and critical state strength. Overall, modification of peat with nanosilica leads to improvements in strength and formation of composites with generally more dilative behaviour. When used as a single stabiliser, a design 15 % to 20 % grade nanosilica solution yields a reasonably high strength although precautions against excessive straining of modified peat soils need to be taken in the first seven days post treatment. At this optimum grade, the loss of strength on further straining is capped to 9 % at plastic strains 1.5 times the peak strain.
{"title":"Stabilisation of peat with colloidal nanosilica","authors":"S. Ghadr, A. Assadi-Langroudi, Ching Hung","doi":"10.19189/MAP.2019.OMB.STA.1896","DOIUrl":"https://doi.org/10.19189/MAP.2019.OMB.STA.1896","url":null,"abstract":"Colloidal nanosilica hydrosols are electrochemically stabilised polymerised amorphous silica in low viscosity suspensions. They have no known adverse impact on soil health and ecosystem service functions, thereby having a scope for use in groundworks as an alternative low-viscose stabilising material. Six grades of colloidal nanosilica are synthesised through an in-house procedure and introduced to a natural peat soil. The peak and residual compressive strength of compacted and modified soils are measured immediately after treatment and in four strain levels post treatment. Findings suggest that, despite the direct correlation between the nanosilica content and compressive strength, an increase in nanosilica content does not necessarily offer stability at larger strains. This is a major limitation. The particle-level kinematics in modified peat is discussed to gain a new insight into the role played by silica flocs on the build-up of macro-mechanical quantities such as peak and critical state strength. Overall, modification of peat with nanosilica leads to improvements in strength and formation of composites with generally more dilative behaviour. When used as a single stabiliser, a design 15 % to 20 % grade nanosilica solution yields a reasonably high strength although precautions against excessive straining of modified peat soils need to be taken in the first seven days post treatment. At this optimum grade, the loss of strength on further straining is capped to 9 % at plastic strains 1.5 times the peak strain.","PeriodicalId":48721,"journal":{"name":"Mires and Peat","volume":"26 1","pages":"09"},"PeriodicalIF":1.2,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67989412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.19189/MAP.2019.OMB.STA.1786
K. Laasasenaho, F. Renzi, H. Karjalainen, P. Kaparaju, J. Konttinen, J. Rintala
(1) In Finland, in recent years, the combustion of dry reed canary grass (RCG, Phalaris arundinacea) grown intensively on cutover peatlands, has decreased markedly. We therefore made experiments in two areas to assess the alternative of using freshly harvested RCG grown for biogas production on cutover peatland. We measured both biogas production and combustion energy release. (2) The experiments show that the RCG biomass yields in total solids (TS) in both areas, with two cuts a year, were surprisingly small (yields of 2.7 and 4.2 Mg ha-1 [1 Mg ha-1 = 100 g m-2 ]); having biogas and combustion potentials, on the two areas, of 277–348 dm3 kg-1 VS (volatile solids) and 14.8–16.3 MJ kg-1 TS, and 11.8–21.9 MWh ha-1 in combustion. (3) Fresh RCG may produce larger biomass yields if cut several times a year, together with lower lignin proportion, and better suitability for biogas production compared with spring harvested dry RCG. (4) For cutover peatlands there are several after-use possibilities, however, with different benefits and challenges. For example, peat soil emissions may be affected during the after-use period, and this should be considered when planning the use of cutover peatlands.
{"title":"Biogas and combustion potential of fresh reed canary grass grown on cutover peatland","authors":"K. Laasasenaho, F. Renzi, H. Karjalainen, P. Kaparaju, J. Konttinen, J. Rintala","doi":"10.19189/MAP.2019.OMB.STA.1786","DOIUrl":"https://doi.org/10.19189/MAP.2019.OMB.STA.1786","url":null,"abstract":"(1) In Finland, in recent years, the combustion of dry reed canary grass (RCG, Phalaris arundinacea) grown intensively on cutover peatlands, has decreased markedly. We therefore made experiments in two areas to assess the alternative of using freshly harvested RCG grown for biogas production on cutover peatland. We measured both biogas production and combustion energy release. (2) The experiments show that the RCG biomass yields in total solids (TS) in both areas, with two cuts a year, were surprisingly small (yields of 2.7 and 4.2 Mg ha-1 [1 Mg ha-1 = 100 g m-2 ]); having biogas and combustion potentials, on the two areas, of 277–348 dm3 kg-1 VS (volatile solids) and 14.8–16.3 MJ kg-1 TS, and 11.8–21.9 MWh ha-1 in combustion. (3) Fresh RCG may produce larger biomass yields if cut several times a year, together with lower lignin proportion, and better suitability for biogas production compared with spring harvested dry RCG. (4) For cutover peatlands there are several after-use possibilities, however, with different benefits and challenges. For example, peat soil emissions may be affected during the after-use period, and this should be considered when planning the use of cutover peatlands.","PeriodicalId":48721,"journal":{"name":"Mires and Peat","volume":"26 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67989404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.19189/MAP.2019.AJB.STA.1902
S. Watts
Revegetation of eroded bare peat is commonly facilitated by the import of artificial resources and genetic material (lime, seed and fertiliser), but such techniques are less suitable for remote upland locations with sensitive local flora. Using a BACI (Before-After-Control-Impact) approach, this study explores the effectiveness of alternative treatments (heather (Calluna vulgaris) brash cut onsite and two types of geotextiles) in the following four years at grazed and ungrazed sites at Ben Lawers National Nature Reserve. After an initial colonisation, the mean vegetation cover in grazed plots degraded to 9.4 %, demonstrating that restoration using these methods is impeded by trampling impacts of large herbivores. The vegetation cover and number of indicator species increased annually at the ungrazed site. A significantly greater cover (>85 %) occurred at plots where thick brash (>85 % ground cover) had been topped with GeoJute netting, but plots with only heather brash still reached 56.6 % cover. It provided a suitable seed source and colonising substrate for appropriate local peatbog species, while additional planting of C. vulgaris cuttings did not significantly increase vegetation cover in comparison to unplanted plots. These results show that short-term restoration of bare peat can be promoted using minimal interventions and onsite resources in the absence of grazing.
{"title":"Revegetation of upland eroded bare peat using heather brash and geotextiles in the presence and absence of grazing","authors":"S. Watts","doi":"10.19189/MAP.2019.AJB.STA.1902","DOIUrl":"https://doi.org/10.19189/MAP.2019.AJB.STA.1902","url":null,"abstract":"Revegetation of eroded bare peat is commonly facilitated by the import of artificial resources and genetic material (lime, seed and fertiliser), but such techniques are less suitable for remote upland locations with sensitive local flora. Using a BACI (Before-After-Control-Impact) approach, this study explores the effectiveness of alternative treatments (heather (Calluna vulgaris) brash cut onsite and two types of geotextiles) in the following four years at grazed and ungrazed sites at Ben Lawers National Nature Reserve. After an initial colonisation, the mean vegetation cover in grazed plots degraded to 9.4 %, demonstrating that restoration using these methods is impeded by trampling impacts of large herbivores. The vegetation cover and number of indicator species increased annually at the ungrazed site. A significantly greater cover (>85 %) occurred at plots where thick brash (>85 % ground cover) had been topped with GeoJute netting, but plots with only heather brash still reached 56.6 % cover. It provided a suitable seed source and colonising substrate for appropriate local peatbog species, while additional planting of C. vulgaris cuttings did not significantly increase vegetation cover in comparison to unplanted plots. These results show that short-term restoration of bare peat can be promoted using minimal interventions and onsite resources in the absence of grazing.","PeriodicalId":48721,"journal":{"name":"Mires and Peat","volume":"26 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67989427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.19189/MAP.2019.SNPG.394
Samer Elshehawi, A. E. Vilches, O. Aleksans, M. Pakalne, L. Wołejko, P. Schot, A. Grootjans
Slitere National Park in Latvia is home to rich fens with many endangered and threatened plant species. This study aims to address how the hydrological systems affect vegetation biodiversity (cf. Wolejko et al. 2019) in the mire systems of the National Park: the base-rich inter-dune mires and extremely base-rich calcareous fens. Groundwater samples from these areas were collected for measurements of ion composition and natural isotopes of C, H and O. Also, we simulated groundwater flow paths from the highest local topographical point (a nearby sandy plateau) to the sea, and calculated the residence times of these groundwater flows. The results show that the inter-dune mires are supplied by a mixture of local and regional groundwater systems. The groundwater supply at one of the inter-dune mires was dominated by local groundwater flow from adjacent dunes, but we also detected a small input of calcareous water. This dominance of local groundwater may have resulted from the presence of drainage ditches and a small stream that drains into the Baltic Sea. In contrast, the extremely base-rich fens were found to be solely dependent on regional groundwater which is likely to discharge at the plateau foothills due to the presence of fault structures. Thus, the mires in Slitere National Park are not as undisturbed as was previously believed. Drainage may have affected the original hydrological flow paths. Further research on the extent of these changes is recommended to preserve the endangered species and high biodiversity of these fens. Also, in order to trace the origin of groundwater flows, further investigation into the larger landscape beyond the plateau might be required.
拉脱维亚的斯利特尔国家公园拥有丰富的沼泽，有许多濒危和受威胁的植物物种。本研究旨在解决水文系统如何影响国家公园沼泽系统中的植被生物多样性(cf. Wolejko et al. 2019):富含碱性的沙丘间沼泽和极其丰富的钙质沼泽。采集了这些地区的地下水样本，测量了这些地区的离子组成和C、H、o的天然同位素，并模拟了地下水从当地最高地形点(附近的沙质高原)到海洋的流动路径，计算了这些地下水流动的停留时间。结果表明，沙丘间水坑是由局部和区域地下水系统共同供给的。其中一个沙丘间矿坑的地下水供应主要来自邻近沙丘的当地地下水，但我们也发现了少量钙质水的输入。当地地下水占主导地位可能是由于存在排水沟和一条流入波罗的海的小溪。相比之下，发现极富碱性的沼泽完全依赖于区域地下水，由于断层结构的存在，地下水很可能在高原山麓排出。因此，斯利特尔国家公园的泥潭并不像以前认为的那样不受干扰。排水可能影响了原来的水文流动路径。建议进一步研究这些变化的程度，以保护这些濒危物种和这些沼泽的高度生物多样性。此外，为了追踪地下水流动的起源，可能需要对高原以外的更大景观进行进一步调查。
{"title":"Natural isotopes support groundwater origin as a driver of mire type and biodiversity in Slitere National Park, Latvia","authors":"Samer Elshehawi, A. E. Vilches, O. Aleksans, M. Pakalne, L. Wołejko, P. Schot, A. Grootjans","doi":"10.19189/MAP.2019.SNPG.394","DOIUrl":"https://doi.org/10.19189/MAP.2019.SNPG.394","url":null,"abstract":"Slitere National Park in Latvia is home to rich fens with many endangered and threatened plant species. This study aims to address how the hydrological systems affect vegetation biodiversity (cf. Wolejko et al. 2019) in the mire systems of the National Park: the base-rich inter-dune mires and extremely base-rich calcareous fens. Groundwater samples from these areas were collected for measurements of ion composition and natural isotopes of C, H and O. Also, we simulated groundwater flow paths from the highest local topographical point (a nearby sandy plateau) to the sea, and calculated the residence times of these groundwater flows. The results show that the inter-dune mires are supplied by a mixture of local and regional groundwater systems. The groundwater supply at one of the inter-dune mires was dominated by local groundwater flow from adjacent dunes, but we also detected a small input of calcareous water. This dominance of local groundwater may have resulted from the presence of drainage ditches and a small stream that drains into the Baltic Sea. In contrast, the extremely base-rich fens were found to be solely dependent on regional groundwater which is likely to discharge at the plateau foothills due to the presence of fault structures. Thus, the mires in Slitere National Park are not as undisturbed as was previously believed. Drainage may have affected the original hydrological flow paths. Further research on the extent of these changes is recommended to preserve the endangered species and high biodiversity of these fens. Also, in order to trace the origin of groundwater flows, further investigation into the larger landscape beyond the plateau might be required.","PeriodicalId":48721,"journal":{"name":"Mires and Peat","volume":"26 1","pages":"01"},"PeriodicalIF":1.2,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67989470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.19189/MAP.2019.OMB.399
A. Kämäräinen, K. Jokinen, L. Lindén
{"title":"Adding Sphagnum to peat growing medium improves plant performance under water restricting conditions","authors":"A. Kämäräinen, K. Jokinen, L. Lindén","doi":"10.19189/MAP.2019.OMB.399","DOIUrl":"https://doi.org/10.19189/MAP.2019.OMB.399","url":null,"abstract":"","PeriodicalId":48721,"journal":{"name":"Mires and Peat","volume":"26 1","pages":"13"},"PeriodicalIF":1.2,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67989346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-09DOI: 10.19189/MAP.2018.AJB.391
A. Sallinen, S. Tuominen, T. Kumpula, T. Tahvanainen
Biodiversity Centre, Finnish Environment Institute SYKE, Kuhmo, Finland Biodiversity Centre, Finnish Environment Institute SYKE, Helsinki, Finland Department of Geographical and Historical Studies, University of Eastern Finland, Joensuu, Finland Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu, Finland _______________________________________________________________________________________
{"title":"Undrained peatland areas disturbed by surrounding drainage: a large scale GIS analysis in Finland with a special focus on aapa mires","authors":"A. Sallinen, S. Tuominen, T. Kumpula, T. Tahvanainen","doi":"10.19189/MAP.2018.AJB.391","DOIUrl":"https://doi.org/10.19189/MAP.2018.AJB.391","url":null,"abstract":"Biodiversity Centre, Finnish Environment Institute SYKE, Kuhmo, Finland Biodiversity Centre, Finnish Environment Institute SYKE, Helsinki, Finland Department of Geographical and Historical Studies, University of Eastern Finland, Joensuu, Finland Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu, Finland _______________________________________________________________________________________","PeriodicalId":48721,"journal":{"name":"Mires and Peat","volume":"1 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2019-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45336150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-01DOI: 10.19189/MAP.2019.OMB.STA.1815
Samer Elshehawi, M. Gabriel, L. Pretorius, S. Bukhosini, M. Butler, J. Plicht, P. Grundling, A. Grootjans
The Vasi peatland complex is situated in the northeast of South Africa. It is an unprotected area surrounded by pine (Pinus sp.) and blue gum (Eucalyptus sp.) plantations. Little is known about the conditioning factors for the area’s development and causes of degradation. In order to understand the ecohydrological system of this complex, water tables and ionic composition of surface water and groundwater, as well as natural isotopes of oxygen, hydrogen and carbon, were measured. Macrofossils and radiocarbon dating of the peat layer were used to describe the historical environmental conditions. We found that peat accumulation started during the Early Holocene and was initiated by terrestrialisation of inter-dune lakes. Our results also show that the Vasi peatland complex is primarily dependent on a perched water table due to the presence of iron-rich deposits close to the surface (i.e. KwaMbonambi Formation). The Vasi peatland basins appear to be hydrologically connected and some basins show indications of cascading through-flow systems, which means that the water flows from a higher basin to a lower one through the permeable parts of the sand dunes and peat layers. The stratigraphy indicates continuous peat accumulation, and thus that the water table was perennially high for thousands of years, despite evidence of the occasional natural occurrence of fires. We conclude that the most likely cause of the observed signs of degradation is land use change, i.e. the recent establishment of plantations, which affect the groundwater system.
{"title":"Ecohydrology and causes of peat degradation at the Vasi peatland, South Africa","authors":"Samer Elshehawi, M. Gabriel, L. Pretorius, S. Bukhosini, M. Butler, J. Plicht, P. Grundling, A. Grootjans","doi":"10.19189/MAP.2019.OMB.STA.1815","DOIUrl":"https://doi.org/10.19189/MAP.2019.OMB.STA.1815","url":null,"abstract":"The Vasi peatland complex is situated in the northeast of South Africa. It is an unprotected area surrounded by pine (Pinus sp.) and blue gum (Eucalyptus sp.) plantations. Little is known about the conditioning factors for the area’s development and causes of degradation. In order to understand the ecohydrological system of this complex, water tables and ionic composition of surface water and groundwater, as well as natural isotopes of oxygen, hydrogen and carbon, were measured. Macrofossils and radiocarbon dating of the peat layer were used to describe the historical environmental conditions. We found that peat accumulation started during the Early Holocene and was initiated by terrestrialisation of inter-dune lakes. Our results also show that the Vasi peatland complex is primarily dependent on a perched water table due to the presence of iron-rich deposits close to the surface (i.e. KwaMbonambi Formation). The Vasi peatland basins appear to be hydrologically connected and some basins show indications of cascading through-flow systems, which means that the water flows from a higher basin to a lower one through the permeable parts of the sand dunes and peat layers. The stratigraphy indicates continuous peat accumulation, and thus that the water table was perennially high for thousands of years, despite evidence of the occasional natural occurrence of fires. We conclude that the most likely cause of the observed signs of degradation is land use change, i.e. the recent establishment of plantations, which affect the groundwater system.","PeriodicalId":48721,"journal":{"name":"Mires and Peat","volume":"24 1","pages":"1-21"},"PeriodicalIF":1.2,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44289939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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