Ain Kull - Academia.edu (original) (raw)

Papers by Ain Kull

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WIT Transactions on Ecology and the Environment, Sep 10, 2003

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Ecology and the Environment, Jun 28, 2006

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<p>Nutrient-rich organic soils are one of the largest key sources of greenh... more <p>Nutrient-rich organic soils are one of the largest key sources of greenhouse gas (GHG) emissions in cool moist climate regions in Europe, and around 15 Mha of wetlands are drained for forestry across the world's temperate and boreal areas. Drainage promotes the decomposition of the organic material stored in these naturally water-saturated organic soils, turning the wetland from a carbon sink into an emitter of CO<span xml:lang="EN-US"><span><sub>2</sub></span></span>. Lower soil water content in drained histosols leads to reduced CH<sub>4</sub> emission, while N<span xml:lang="EN-US"><span><sub>2</sub></span></span>O emission can increase due to increased mineralization and more favorable conditions for nitrification. However, detailed information of GHG emissions from drained organic soils under different land use and management in the hemiboreal zone is still scarce.  </p><p xml:lang="EN-US"><span xml:lang="EN-US">We conducted a full-year study at drained peatland sites with different land uses to assess the impact of drainage and land-use on GHG fluxes in Estonia. We investigated ten sites: (I) five forests with different tree species, (II) three grasslands with different water regimes, (III) cropland and (IV) natural wetland (fen). The GHG fluxes were measured twice per month using the manual static (CH</span><sub>4</sub> and N<sub>2</sub>O) and dynamic (heterotrophic respiration (CO<span xml:lang="EN-US"><span><sub>2</sub></span></span>)) closed chamber method from Jan 2020 to Dec 2021. Additionally, groundwater level, soil temperature and moisture were measured hourly with automatic loggers to determine soil conditions.   </p><p xml:lang="EN-US"><span xml:lang="EN-US">Our preliminary results show that all drained forest soils were annual CH<sub>4</sub> sinks (−59.4 ± 2.5 µg m</span><span xml:lang="EN-US"><span><sup>-2</sup></span></span> h<sup>-1</sup>, mean ± SE). However, CH<span xml:lang="EN-US"><span><sub>4</sub></span></span> uptake from the studied fen, crop and grasslands were lower, –13.2 ± 4.4, -12.2 ± 2.0 and -8.2 ± 3.3 µg m<span xml:lang="EN-US"><span><sup>-2</sup></span></span> h<sup>-1</sup>, respectively, while grassland with poor drainage soil was a less source of CH<sub>4 </sub><span xml:lang="EN-US">emission. Most of the sites were annual emitters of N</span><sub>2</sub>O; forest sites were higher emitters (15.9 ± 2.3 µg m<sup>-2</sup> h<sup>-1</sup>) than cropland (12.7 ± 4.1 µg m<span xml:lang="EN-US"><span><sup>-2</sup></span></span> h<sup>-1</sup>) and fen soils (6.3 ± 1.1 µg m<span xml:lang="EN-US"><span><sup>-2</sup></span></span> h<sup>-1</sup>). N<sub>2</sub>O fluxes from grasslands depend on drainage intensity and the site with poor drainage emitted less. Higher N<span xml:lang="EN-US"><span><sub>2</sub></span></span>O emissions and temporal variability were associated with sites where the water level had high seasonal fluctuations. Soil CO<sub>2</sub> fluxes (heterotrophic respiration) were highest from grasslands and peaked over all the study sites during the summer. Methane flux had a statistically significant correlation with water level and soil moisture, while N<sub>2</sub>O flux was controlled by soil temperature, having higher emissions in a warmer…

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WIT Transactions on Biomedicine and Health, Jun 11, 2007

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Agronomy, Apr 22, 2023

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Insects, Nov 25, 2022

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Wind is one of the main renewable energy resources. The planning of offshore wind farms is an ong... more Wind is one of the main renewable energy resources. The planning of offshore wind farms is an ongoing process and the Gulf of Riga region is no exception. Accurate information on marine wind field with high spatial and temporal resolution is therefore needed. Rough ice conditions in the Gulf of Riga could impose a threat to the construction and operation

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In the frame of the Estonia - Latvia programme's project GORWIND we have looked at the genera... more In the frame of the Estonia - Latvia programme's project GORWIND we have looked at the general policy descriptions, the laws and regulations on choosing the development areas at the coastal zone and in marine locations and the consideration of the wind energy question in the territorial plans of the local governments around the Gulf of Riga. The differences between two countries are mostly in the details of procedures. Still, the problems and inconsistencies are quite in common - a missing stability in legislation and coordinated development of infrastructure. The territorial plans of Latvian local governments in the Gulf of Riga area mostly have not regarded the existence of the wind park as a serious option. Already existing wind parks and turbines are located outside the Gulf area and therefore the development in this sense is somewhat delayed in Latvia. The situation in Estonia differs substantially as all coastal local governments have considered the possibility of having wind turbines in their territorial plans.

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EGU General Assembly Conference Abstracts, Apr 1, 2019

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<p>In the terrestrial biosphere, peatlands represent the most important long-term s... more <p>In the terrestrial biosphere, peatlands represent the most important long-term soil carbon storage. They cover only 3% of the land surface but are responsible for about one-third of the total. Ecosystem degradation and changes made in hydrology may affect the biogeochemistry of peatlands and, together with projected global warming, may lead to significant changes in greenhouse gas fluxes. Aeration of peatlands increases organic matter's aerobic decomposition and enhances wetlands’ change from a net carbon sink to a carbon dioxide source and low soil water content in drained histosols results in lower CH<sub>4</sub> emissions. In contrast, N<sub>2</sub>O emissions may increase due to increased mineralization and more favorable conditions for nitrification.</p><p>However, soil CH<sub>4</sub> and N<sub>2</sub>O fluxes in peatlands are spatially and temporally (interannual, seasonal) variable, and there is little detailed information on drained nutrient-rich organic soils in the hemiboreal zone. We conducted a two-year study in drained peatland forests with different tree species Scots pine<em> </em>(<em>Pinus sylvestris</em>), Norway spruce (<em>Picea abies</em><em>), </em>birch<em> </em>(<em>Betula sp</em><em>.</em>), and black alder (<em>Alnus glutinosa</em>) and with various water levels and a natural wetland (fen) as a reference site in Estonia and Latvia from January 2021 to December 2022.</p><p>CH<sub>4</sub> and N<sub>2</sub>O fluxes were measured twice per month using the manual static chamber method. Environmental parameters in soil, such as groundwater level, temperature, and moisture were monitored and stored hourly by a data logger. Detailed studies of soil physio-chemical parameters and microbial community were conducted to relate greenhouse gas fluxes with environmental conditions.</p><p>Our preliminary results for the first year showed that all drained forest soils with low groundwater levels were annual methane sinks (−48.9 ± 12.9 μg m<sup>−‍2</sup> h<sup>−‍1</sup>), whereas the reference fen studied had a higher emission potential of 396 ± 214 μg m<sup>−‍2</sup> h<sup>−‍1</sup>. In contrast, birch and alder forests with poorly drained soils consumed less CH<sub>4</sub> and were annual emitters than artificially drained sites. Methane flux had a statistically significant correlation with water level and soil temperature. Most of the sites were annual emitters of N<sub>2</sub>O; wetter forest sites were higher emitters (21.0 ± 10.49 μg m<sup>−‍2</sup> h<sup>−‍1</sup>) than drier sites (17.97 ± 4.8 μg m<sup>−‍2</sup> h<sup>−‍1</sup>). Higher N<sub>2</sub>O emissions and temporal variability were associated with sites where water levels exhibited large seasonal fluctuations. N<sub>2</sub>O flux was controlled by soil temperature and moisture content, and emission peaks occurred in spring (freeze-thaw period).</p><p>This research was supported by the LIFE programme project "Demonstration of climate change mitigation potential of nutrients rich organic soils in the Baltic States and Finland", (2019-2023, LIFE OrgBalt, LIFE18 274CCM/LV/001158).</p>

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IGARSS 2022 - 2022 IEEE International Geoscience and Remote Sensing Symposium

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<p>Over the past decade, we witnessed a rapid growth in the use of social m... more <p>Over the past decade, we witnessed a rapid growth in the use of social media data when assessing  cultural ecosystem services (CESs), like modelling the supply-demand relationships. Researchers increasingly use user-generated content (predominantly geotagged pictures and texts from Flickr, Twitter, VK.com) as a spatially explicit proxy of CES demand. However, for modelling CES supply most of such studies relied on simplistic geospatial data, such as land cover and digital elevation models. As a result, our understanding of the favourable environmental conditions underlying good landscape experience remains weak and overly generic.</p><p>Our study aims to detect the spatial disparities between population density and CES supply in Estonia in order to prioritise them for further in-depth CES assessment and green and blue infrastructure improvements. We relied on Flickr and VK.com photographs to detect the usage of three CESs: passive landscape watching, active outdoor recreation, and wildlife watching (biota observations at organism and community levels) with automated image content recognition via Clarifai API and subsequent topic modelling. Then, we used Landsat-8 cloudless mosaic, digital elevation and digital surface models, as well as land cover model to derive 526 environmental variables (textural, spectral indices and other indicators of landscape physiognomy) via the Google Earth Engine platform. We conducted an ensemble environmental niche modelling to analyse the relative strength and directions of relationships between these predictors and the observed occurrence of CES demand. Based on multicollinearity and relative importance analysis, we selected 21 relevant and non-collinear indicators of CES supply. With these indicators as inputs, we then trained five models, popular in environmental niche modelling: Boosted Regression Trees, Generalized Linear Model, Multivariate Adaptive Regression Spline, Maxent, and Random Forest. Random Forest performed better than the other models for all three CES types, with the average 10-fold cross-validation area under curve > 0.9 for landscape watching, >0.87 for outdoor recreation, and >0.85 for wildlife watching. Our modelling allowed us to estimate the share of the Estonian population residing in the spatial clusters of systematically high and low environmental suitability for three considered CESs. The share of the population residing in the clusters of low environmental suitability for landscape watching, outdoor recreation, and wildlife watching is 5.5%, 3.1%, and 7.3%, respectively. These results indicate that dozens of thousands of people in Estonia (population is >1.3 million) likely have fewer opportunities for everyday usage of considered CESs. However, these results are biased as there was not enough evidence in social media for CES use in some of these areas.</p><p>Although our results should be treated with caution, because social media data are likely to contain a considerable sampling bias, we have demonstrated the added value of remote sensing data for CES supply estimation. Given nearly global and continuously updated satellite imagery archives, remote sensing opens new perspectives for monitoring the loss and gains in landscape suitability for CES across temporal and spatial scales. As such, we can better account for the intangible underlying geospatial features that can influence  economic and environmental decision-making.</p>

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PLOS ONE, 2018

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Zenodo (CERN European Organization for Nuclear Research), Apr 14, 2023

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<p>Lateral carbon (C) flux results from complex interplay of formation, transport a... more <p>Lateral carbon (C) flux results from complex interplay of formation, transport and biodegradation of dissolved organic carbon (DOC), and is an important but rather scarcely studied component of the C balance in peatlands. Temperature and water table (WT) are the primary factors regulating peat CO<sub>2</sub> emissions and the release of DOC. DOC dynamics in soil is complicated because the DOC storage is continuously increased by the decomposition of solid organic matter, but simultaneously decreased by biodegradation. Any upscaling of lateral C fluxes requires understanding these coinciding processes. We studied the effect of temperature and WT on CO<sub>2</sub> emission and DOC concentration in pore water while incubating peat columns (diameter 0.2 m height 0.5 m) in laboratory conditions for eight months. Peat columns were extracted from drained forested peatlands in Finland, Estonia, Sweden and Ireland. WT was set to -0.2 m and -0.4 m distance from the column upper end. During the incubation, the temperature ranged between 18  and 34 ⁰C. DOC samples were extracted in monthly intervals from the columns using Rhizon soil water samplers. At the same time CO<sub>2</sub> emission was measured from the headspace of the column. DOC biodegradation to CO<sub>2</sub> and its temperature sensitivity was studied by incubating soil water samples in controlled conditions. The quality (aromaticity) of DOC was investigated with a UV-VIS spectrophotometer. The effect of temperature on DOC concentration was not straightforward unlike in the case of CO<sub>2</sub> emission. DOC concentration increased steepest when the temperature exceeded 25  ⁰C, whereas with lower temperatures DOC was unchanged or slightly decreased. This can be due to different temperature sensitivities of DOC release and its biodegradation. Low WT resulted in high CO<sub>2</sub> emissions and DOC concentrations. These results are important in developing ecosystem models accounting for lateral C fluxes and the effects of forest management, drainage and climate change in managed peatlands.</p>

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<p>Organic soils are one of the largest natural terrestrial carbon stores, especial... more <p>Organic soils are one of the largest natural terrestrial carbon stores, especially in boreal, temperate, and tropical wet climates. In these environments, scarcity of oxygen due to soil wetness has enabled the accumulation of organic carbon deposits over the past millennia. In Europe, organic soils account for only 3% of total agricultural land. Yet, they play a significant role in meeting Europe's 2030 and 2050 climate change mitigation targets. However, drainage of these soils, as a common management practice aiming for higher agricultural productivity, transforms these carbon-rich soils into a significant GHG source.</p> <p>Water-level management practices are critical in agriculture to minimize soil degradation and nutrient leaching. Fluctuations in water levels may alter soil physical and chemical conditions and potentially cause GHG emissions. Deep draining leads to an increase in carbon dioxide (CO<sub>2</sub>) and nitrous oxide (N<sub>2</sub>O) emissions due to increased soil mineralization. On the other hand, methane (CH<sub>4</sub>) emissions are lower compared to natural wetlands where soil drainage and tillage do not occur. Land use, climate zone, soil nutrient status, fertilization, and drainage status are closely related to estimating GHG budgets from managed sites on organic soils.</p> <p>Available data on actual GHG emissions from drained and nutrient-rich organic soils under different management practices show considerable variation. Therefore our study's main objectives are: (I) to update GHG emission factors for organic soils in drained croplands and grasslands and (ii) to calculate soil carbon and nitrogen budgets applicable to the Baltic countries. A two-year study was conducted from January 2021 to December 2022 to assess the impact of drainage and land use on GHG fluxes in the Baltic countries.</p> <p>Fluxes in croplands and perennial grassland on nutrient-rich organic soils with different drainage conditions were determined by groups: (I) excessively drained croplands, (II) excessively drained grasslands, (III) moderately drained grasslands, (IV) rewetted grasslands, and (V) non-managed fens as reference sites. Measurements were done monthly (Latvia and Lithuania) or twice per month (Estonia) using the manual static dark chamber method (N<sub>2</sub>O, CH<sub>4</sub>), the dynamic transparent chamber method for net ecosystem exchange, and the dynamic dark chamber for soil heterotrophic respiration (CO<sub>2</sub>). In addition, we measured associated environmental parameters (water table level, soil moisture and temperature, and solar radiation). For biomass analyses, we took samples once in the measurement period.</p> <p>Our preliminary results show that all grasslands were annual CH<sub>4</sub> sinks, while fens soils in natural status were a source of CH<sub>4</sub>. All studied sites were N<sub>2</sub>O sources on an annual basis, and croplands were the strongest emitters, as was expected. Higher N<sub>2</sub>O emissions and temporal variability were associated with sites characterized by high groundwater levels with high seasonal fluctuations. Soil heterotrophic respiration fluxes peaked over all the study sites during the summer. As the last field campaign shortly ended, more detailed data analyses will be presented at the conference.</p> <p><em>This research was supported by the LIFE programme project "Demonstration of climate change mitigation potential of nutrients rich organic soils in Baltic States and Finland", (2019-2023, LIFE OrgBalt, LIFE18 274CCM/LV/001158).</em></p>

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Projekti RITA1 KAUGSEIRE käigus töötati välja kaugseire andmete töötlemise metoodid/prototüübid, ... more Projekti RITA1 KAUGSEIRE käigus töötati välja kaugseire andmete töötlemise metoodid/prototüübid, mis võimaldavad parandada mitmeid järgmisi seirerakendusi ja riiklike teenuseid: (1) üleujutuste seire satelliitpiltidel sisemaal ja rannikul; (2) veetaseme seire kasutades altimeetria andmeid; (3) veetaseme prognoosi täpsustamine satelliitaltimeetria andmetega; (4) veekogu ökoloogilise klassi korrektsioon vastavalt veetaseme sesoonsele muutusele; (5) soode niiskus režiimi jälgimine kaugseire meetodiga; (6) maardlate (s.h. turbamaardlate) seire satelliitpiltidelt.

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WIT Transactions on Ecology and the Environment, Sep 10, 2003

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Ecology and the Environment, Jun 28, 2006

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<p>Nutrient-rich organic soils are one of the largest key sources of greenh... more <p>Nutrient-rich organic soils are one of the largest key sources of greenhouse gas (GHG) emissions in cool moist climate regions in Europe, and around 15 Mha of wetlands are drained for forestry across the world's temperate and boreal areas. Drainage promotes the decomposition of the organic material stored in these naturally water-saturated organic soils, turning the wetland from a carbon sink into an emitter of CO<span xml:lang="EN-US"><span><sub>2</sub></span></span>. Lower soil water content in drained histosols leads to reduced CH<sub>4</sub> emission, while N<span xml:lang="EN-US"><span><sub>2</sub></span></span>O emission can increase due to increased mineralization and more favorable conditions for nitrification. However, detailed information of GHG emissions from drained organic soils under different land use and management in the hemiboreal zone is still scarce.  </p><p xml:lang="EN-US"><span xml:lang="EN-US">We conducted a full-year study at drained peatland sites with different land uses to assess the impact of drainage and land-use on GHG fluxes in Estonia. We investigated ten sites: (I) five forests with different tree species, (II) three grasslands with different water regimes, (III) cropland and (IV) natural wetland (fen). The GHG fluxes were measured twice per month using the manual static (CH</span><sub>4</sub> and N<sub>2</sub>O) and dynamic (heterotrophic respiration (CO<span xml:lang="EN-US"><span><sub>2</sub></span></span>)) closed chamber method from Jan 2020 to Dec 2021. Additionally, groundwater level, soil temperature and moisture were measured hourly with automatic loggers to determine soil conditions.   </p><p xml:lang="EN-US"><span xml:lang="EN-US">Our preliminary results show that all drained forest soils were annual CH<sub>4</sub> sinks (−59.4 ± 2.5 µg m</span><span xml:lang="EN-US"><span><sup>-2</sup></span></span> h<sup>-1</sup>, mean ± SE). However, CH<span xml:lang="EN-US"><span><sub>4</sub></span></span> uptake from the studied fen, crop and grasslands were lower, –13.2 ± 4.4, -12.2 ± 2.0 and -8.2 ± 3.3 µg m<span xml:lang="EN-US"><span><sup>-2</sup></span></span> h<sup>-1</sup>, respectively, while grassland with poor drainage soil was a less source of CH<sub>4 </sub><span xml:lang="EN-US">emission. Most of the sites were annual emitters of N</span><sub>2</sub>O; forest sites were higher emitters (15.9 ± 2.3 µg m<sup>-2</sup> h<sup>-1</sup>) than cropland (12.7 ± 4.1 µg m<span xml:lang="EN-US"><span><sup>-2</sup></span></span> h<sup>-1</sup>) and fen soils (6.3 ± 1.1 µg m<span xml:lang="EN-US"><span><sup>-2</sup></span></span> h<sup>-1</sup>). N<sub>2</sub>O fluxes from grasslands depend on drainage intensity and the site with poor drainage emitted less. Higher N<span xml:lang="EN-US"><span><sub>2</sub></span></span>O emissions and temporal variability were associated with sites where the water level had high seasonal fluctuations. Soil CO<sub>2</sub> fluxes (heterotrophic respiration) were highest from grasslands and peaked over all the study sites during the summer. Methane flux had a statistically significant correlation with water level and soil moisture, while N<sub>2</sub>O flux was controlled by soil temperature, having higher emissions in a warmer…

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WIT Transactions on Biomedicine and Health, Jun 11, 2007

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Agronomy, Apr 22, 2023

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Insects, Nov 25, 2022

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Wind is one of the main renewable energy resources. The planning of offshore wind farms is an ong... more Wind is one of the main renewable energy resources. The planning of offshore wind farms is an ongoing process and the Gulf of Riga region is no exception. Accurate information on marine wind field with high spatial and temporal resolution is therefore needed. Rough ice conditions in the Gulf of Riga could impose a threat to the construction and operation

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In the frame of the Estonia - Latvia programme's project GORWIND we have looked at the genera... more In the frame of the Estonia - Latvia programme's project GORWIND we have looked at the general policy descriptions, the laws and regulations on choosing the development areas at the coastal zone and in marine locations and the consideration of the wind energy question in the territorial plans of the local governments around the Gulf of Riga. The differences between two countries are mostly in the details of procedures. Still, the problems and inconsistencies are quite in common - a missing stability in legislation and coordinated development of infrastructure. The territorial plans of Latvian local governments in the Gulf of Riga area mostly have not regarded the existence of the wind park as a serious option. Already existing wind parks and turbines are located outside the Gulf area and therefore the development in this sense is somewhat delayed in Latvia. The situation in Estonia differs substantially as all coastal local governments have considered the possibility of having wind turbines in their territorial plans.

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EGU General Assembly Conference Abstracts, Apr 1, 2019

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<p>In the terrestrial biosphere, peatlands represent the most important long-term s... more <p>In the terrestrial biosphere, peatlands represent the most important long-term soil carbon storage. They cover only 3% of the land surface but are responsible for about one-third of the total. Ecosystem degradation and changes made in hydrology may affect the biogeochemistry of peatlands and, together with projected global warming, may lead to significant changes in greenhouse gas fluxes. Aeration of peatlands increases organic matter's aerobic decomposition and enhances wetlands’ change from a net carbon sink to a carbon dioxide source and low soil water content in drained histosols results in lower CH<sub>4</sub> emissions. In contrast, N<sub>2</sub>O emissions may increase due to increased mineralization and more favorable conditions for nitrification.</p><p>However, soil CH<sub>4</sub> and N<sub>2</sub>O fluxes in peatlands are spatially and temporally (interannual, seasonal) variable, and there is little detailed information on drained nutrient-rich organic soils in the hemiboreal zone. We conducted a two-year study in drained peatland forests with different tree species Scots pine<em> </em>(<em>Pinus sylvestris</em>), Norway spruce (<em>Picea abies</em><em>), </em>birch<em> </em>(<em>Betula sp</em><em>.</em>), and black alder (<em>Alnus glutinosa</em>) and with various water levels and a natural wetland (fen) as a reference site in Estonia and Latvia from January 2021 to December 2022.</p><p>CH<sub>4</sub> and N<sub>2</sub>O fluxes were measured twice per month using the manual static chamber method. Environmental parameters in soil, such as groundwater level, temperature, and moisture were monitored and stored hourly by a data logger. Detailed studies of soil physio-chemical parameters and microbial community were conducted to relate greenhouse gas fluxes with environmental conditions.</p><p>Our preliminary results for the first year showed that all drained forest soils with low groundwater levels were annual methane sinks (−48.9 ± 12.9 μg m<sup>−‍2</sup> h<sup>−‍1</sup>), whereas the reference fen studied had a higher emission potential of 396 ± 214 μg m<sup>−‍2</sup> h<sup>−‍1</sup>. In contrast, birch and alder forests with poorly drained soils consumed less CH<sub>4</sub> and were annual emitters than artificially drained sites. Methane flux had a statistically significant correlation with water level and soil temperature. Most of the sites were annual emitters of N<sub>2</sub>O; wetter forest sites were higher emitters (21.0 ± 10.49 μg m<sup>−‍2</sup> h<sup>−‍1</sup>) than drier sites (17.97 ± 4.8 μg m<sup>−‍2</sup> h<sup>−‍1</sup>). Higher N<sub>2</sub>O emissions and temporal variability were associated with sites where water levels exhibited large seasonal fluctuations. N<sub>2</sub>O flux was controlled by soil temperature and moisture content, and emission peaks occurred in spring (freeze-thaw period).</p><p>This research was supported by the LIFE programme project "Demonstration of climate change mitigation potential of nutrients rich organic soils in the Baltic States and Finland", (2019-2023, LIFE OrgBalt, LIFE18 274CCM/LV/001158).</p>

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IGARSS 2022 - 2022 IEEE International Geoscience and Remote Sensing Symposium

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<p>Over the past decade, we witnessed a rapid growth in the use of social m... more <p>Over the past decade, we witnessed a rapid growth in the use of social media data when assessing  cultural ecosystem services (CESs), like modelling the supply-demand relationships. Researchers increasingly use user-generated content (predominantly geotagged pictures and texts from Flickr, Twitter, VK.com) as a spatially explicit proxy of CES demand. However, for modelling CES supply most of such studies relied on simplistic geospatial data, such as land cover and digital elevation models. As a result, our understanding of the favourable environmental conditions underlying good landscape experience remains weak and overly generic.</p><p>Our study aims to detect the spatial disparities between population density and CES supply in Estonia in order to prioritise them for further in-depth CES assessment and green and blue infrastructure improvements. We relied on Flickr and VK.com photographs to detect the usage of three CESs: passive landscape watching, active outdoor recreation, and wildlife watching (biota observations at organism and community levels) with automated image content recognition via Clarifai API and subsequent topic modelling. Then, we used Landsat-8 cloudless mosaic, digital elevation and digital surface models, as well as land cover model to derive 526 environmental variables (textural, spectral indices and other indicators of landscape physiognomy) via the Google Earth Engine platform. We conducted an ensemble environmental niche modelling to analyse the relative strength and directions of relationships between these predictors and the observed occurrence of CES demand. Based on multicollinearity and relative importance analysis, we selected 21 relevant and non-collinear indicators of CES supply. With these indicators as inputs, we then trained five models, popular in environmental niche modelling: Boosted Regression Trees, Generalized Linear Model, Multivariate Adaptive Regression Spline, Maxent, and Random Forest. Random Forest performed better than the other models for all three CES types, with the average 10-fold cross-validation area under curve > 0.9 for landscape watching, >0.87 for outdoor recreation, and >0.85 for wildlife watching. Our modelling allowed us to estimate the share of the Estonian population residing in the spatial clusters of systematically high and low environmental suitability for three considered CESs. The share of the population residing in the clusters of low environmental suitability for landscape watching, outdoor recreation, and wildlife watching is 5.5%, 3.1%, and 7.3%, respectively. These results indicate that dozens of thousands of people in Estonia (population is >1.3 million) likely have fewer opportunities for everyday usage of considered CESs. However, these results are biased as there was not enough evidence in social media for CES use in some of these areas.</p><p>Although our results should be treated with caution, because social media data are likely to contain a considerable sampling bias, we have demonstrated the added value of remote sensing data for CES supply estimation. Given nearly global and continuously updated satellite imagery archives, remote sensing opens new perspectives for monitoring the loss and gains in landscape suitability for CES across temporal and spatial scales. As such, we can better account for the intangible underlying geospatial features that can influence  economic and environmental decision-making.</p>

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PLOS ONE, 2018

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Zenodo (CERN European Organization for Nuclear Research), Apr 14, 2023

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<p>Lateral carbon (C) flux results from complex interplay of formation, transport a... more <p>Lateral carbon (C) flux results from complex interplay of formation, transport and biodegradation of dissolved organic carbon (DOC), and is an important but rather scarcely studied component of the C balance in peatlands. Temperature and water table (WT) are the primary factors regulating peat CO<sub>2</sub> emissions and the release of DOC. DOC dynamics in soil is complicated because the DOC storage is continuously increased by the decomposition of solid organic matter, but simultaneously decreased by biodegradation. Any upscaling of lateral C fluxes requires understanding these coinciding processes. We studied the effect of temperature and WT on CO<sub>2</sub> emission and DOC concentration in pore water while incubating peat columns (diameter 0.2 m height 0.5 m) in laboratory conditions for eight months. Peat columns were extracted from drained forested peatlands in Finland, Estonia, Sweden and Ireland. WT was set to -0.2 m and -0.4 m distance from the column upper end. During the incubation, the temperature ranged between 18  and 34 ⁰C. DOC samples were extracted in monthly intervals from the columns using Rhizon soil water samplers. At the same time CO<sub>2</sub> emission was measured from the headspace of the column. DOC biodegradation to CO<sub>2</sub> and its temperature sensitivity was studied by incubating soil water samples in controlled conditions. The quality (aromaticity) of DOC was investigated with a UV-VIS spectrophotometer. The effect of temperature on DOC concentration was not straightforward unlike in the case of CO<sub>2</sub> emission. DOC concentration increased steepest when the temperature exceeded 25  ⁰C, whereas with lower temperatures DOC was unchanged or slightly decreased. This can be due to different temperature sensitivities of DOC release and its biodegradation. Low WT resulted in high CO<sub>2</sub> emissions and DOC concentrations. These results are important in developing ecosystem models accounting for lateral C fluxes and the effects of forest management, drainage and climate change in managed peatlands.</p>

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<p>Organic soils are one of the largest natural terrestrial carbon stores, especial... more <p>Organic soils are one of the largest natural terrestrial carbon stores, especially in boreal, temperate, and tropical wet climates. In these environments, scarcity of oxygen due to soil wetness has enabled the accumulation of organic carbon deposits over the past millennia. In Europe, organic soils account for only 3% of total agricultural land. Yet, they play a significant role in meeting Europe's 2030 and 2050 climate change mitigation targets. However, drainage of these soils, as a common management practice aiming for higher agricultural productivity, transforms these carbon-rich soils into a significant GHG source.</p> <p>Water-level management practices are critical in agriculture to minimize soil degradation and nutrient leaching. Fluctuations in water levels may alter soil physical and chemical conditions and potentially cause GHG emissions. Deep draining leads to an increase in carbon dioxide (CO<sub>2</sub>) and nitrous oxide (N<sub>2</sub>O) emissions due to increased soil mineralization. On the other hand, methane (CH<sub>4</sub>) emissions are lower compared to natural wetlands where soil drainage and tillage do not occur. Land use, climate zone, soil nutrient status, fertilization, and drainage status are closely related to estimating GHG budgets from managed sites on organic soils.</p> <p>Available data on actual GHG emissions from drained and nutrient-rich organic soils under different management practices show considerable variation. Therefore our study's main objectives are: (I) to update GHG emission factors for organic soils in drained croplands and grasslands and (ii) to calculate soil carbon and nitrogen budgets applicable to the Baltic countries. A two-year study was conducted from January 2021 to December 2022 to assess the impact of drainage and land use on GHG fluxes in the Baltic countries.</p> <p>Fluxes in croplands and perennial grassland on nutrient-rich organic soils with different drainage conditions were determined by groups: (I) excessively drained croplands, (II) excessively drained grasslands, (III) moderately drained grasslands, (IV) rewetted grasslands, and (V) non-managed fens as reference sites. Measurements were done monthly (Latvia and Lithuania) or twice per month (Estonia) using the manual static dark chamber method (N<sub>2</sub>O, CH<sub>4</sub>), the dynamic transparent chamber method for net ecosystem exchange, and the dynamic dark chamber for soil heterotrophic respiration (CO<sub>2</sub>). In addition, we measured associated environmental parameters (water table level, soil moisture and temperature, and solar radiation). For biomass analyses, we took samples once in the measurement period.</p> <p>Our preliminary results show that all grasslands were annual CH<sub>4</sub> sinks, while fens soils in natural status were a source of CH<sub>4</sub>. All studied sites were N<sub>2</sub>O sources on an annual basis, and croplands were the strongest emitters, as was expected. Higher N<sub>2</sub>O emissions and temporal variability were associated with sites characterized by high groundwater levels with high seasonal fluctuations. Soil heterotrophic respiration fluxes peaked over all the study sites during the summer. As the last field campaign shortly ended, more detailed data analyses will be presented at the conference.</p> <p><em>This research was supported by the LIFE programme project "Demonstration of climate change mitigation potential of nutrients rich organic soils in Baltic States and Finland", (2019-2023, LIFE OrgBalt, LIFE18 274CCM/LV/001158).</em></p>

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Projekti RITA1 KAUGSEIRE käigus töötati välja kaugseire andmete töötlemise metoodid/prototüübid, ... more Projekti RITA1 KAUGSEIRE käigus töötati välja kaugseire andmete töötlemise metoodid/prototüübid, mis võimaldavad parandada mitmeid järgmisi seirerakendusi ja riiklike teenuseid: (1) üleujutuste seire satelliitpiltidel sisemaal ja rannikul; (2) veetaseme seire kasutades altimeetria andmeid; (3) veetaseme prognoosi täpsustamine satelliitaltimeetria andmetega; (4) veekogu ökoloogilise klassi korrektsioon vastavalt veetaseme sesoonsele muutusele; (5) soode niiskus režiimi jälgimine kaugseire meetodiga; (6) maardlate (s.h. turbamaardlate) seire satelliitpiltidelt.

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