Long-term effect of fertilization on the greenhouse gas exchange of low-productive peatland forests

Drainage of peatlands for forestry often leads to carbon dioxide (CO2) 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 CO2, 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 CO2 sink ( + 248-1013 g CO2 m(-2) year(-1)). Decomposition increased on average by 45% ( + 431 g CO2 m(-2) year(-1)) and litter production by 38% ( + 360 g CO2 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 CO2 net emission correlated positively with water table depth and top soil N concentration. Fertilization increased soil CO2 net emission at the drained flark fens on average by 187 g CO2 m(-2) year(-1). At the rich fen, net emission decreased. The N-poor bog exhibited soil CO2 sink both with and without fertilization. Effects on methane and nitrous oxide emissions were small at most sites. The increase in tree stand CO2 sink was higher than the increase in soil CO2 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 CO2 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.Peer reviewe

Predicting hotspots for threatened plant species in boreal peatlands

Understanding the spatial patterns of species distribution and predicting suitable habitats for threatened species are central themes in land use management and planning. In this study, we examined the geographic distribution of threatened mire plant species and identified their national hotspots, i.e. areas with high amounts of suitable habitats for threatened mire plant species. We also determined the main environmental correlates related to the distribution patterns of these species. The specific aims were to: (1) identify the environmental variables that control the distribution of threatened peatland species in a boreal aapa mire zone, Finland; and (2) to identify the richness patterns and hotspots of threatened species. Our results showed that the combination of individual species models offers a useful tool for identifying landscape-scale richness patterns for threatened plant species. The modeling performance was high across the modelled species, and the richness patterns generated by single models coincide with the expected richness pattern based on expert knowledge. The method is therefore a powerful tool for basic biodiversity applications. In cases where reliable models for species occurrences and hotspots can be produced, these models can play a significant role in land-use planning and help managers to meet different conservation challenges

Applying a Multi-Criteria Project Portfolio Tool in Selecting Energy Peat Production Areas

This study demonstrates the characteristics of the new generic project portfolio selection tool YODA (“Your Own Decision Aid”). YODA does not include a mathematical aggregation model. Instead, the decision maker’s preferences are defined by the interactive articulation of acceptance thresholds of project-level decision criteria. Transparency and ease of adopting the method in participatory planning are sought using the method’s simple preference input. The characteristics of the YODA tool are introduced by presenting how it has been applied in participatory land use planning in northern Finland in selecting a combination of peat production sites to attain the goals defined at municipal level. In this process, each stakeholder first constructed a project portfolio that best met his or her preferences. In doing this, acceptance thresholds for project-level decision criteria were defined. In total, eight decision criteria were related to economic value, biodiversity, social impacts, and ecosystem services. Subsequently, the portfolios of different stakeholders were combined in line with the principles of robust portfolio modelling. Core projects were accepted by all stakeholders, while exterior projects were not accepted, and borderline projects by some of the stakeholders. Although the land use planning situation at hand was highly sensitive, because it was related to various aspects of sustainability, the use of YODA provided useful results. The first meeting with stakeholders identified 52 out of 99 sites that none of the stakeholders would use for energy peat production, due to their characteristics, whereas, in the second meeting, a smaller stakeholder group found 18 core projects and 26 borderline projects which could be potential areas for energy peat production. We conclude that YODA—as a generic project portfolio tool—can be used in various planning situations

Applying a Multi-Criteria Project Portfolio Tool in Selecting Energy Peat Production Areas

This study demonstrates the characteristics of the new generic project portfolio selection tool YODA (“Your Own Decision Aid”). YODA does not include a mathematical aggregation model. Instead, the decision maker’s preferences are defined by the interactive articulation of acceptance thresholds of project-level decision criteria. Transparency and ease of adopting the method in participatory planning are sought using the method’s simple preference input. The characteristics of the YODA tool are introduced by presenting how it has been applied in participatory land use planning in northern Finland in selecting a combination of peat production sites to attain the goals defined at municipal level. In this process, each stakeholder first constructed a project portfolio that best met his or her preferences. In doing this, acceptance thresholds for project-level decision criteria were defined. In total, eight decision criteria were related to economic value, biodiversity, social impacts, and ecosystem services. Subsequently, the portfolios of different stakeholders were combined in line with the principles of robust portfolio modelling. Core projects were accepted by all stakeholders, while exterior projects were not accepted, and borderline projects by some of the stakeholders. Although the land use planning situation at hand was highly sensitive, because it was related to various aspects of sustainability, the use of YODA provided useful results. The first meeting with stakeholders identified 52 out of 99 sites that none of the stakeholders would use for energy peat production, due to their characteristics, whereas, in the second meeting, a smaller stakeholder group found 18 core projects and 26 borderline projects which could be potential areas for energy peat production. We conclude that YODA—as a generic project portfolio tool—can be used in various planning situations

Quantification and valuation of ecosystem services to optimize sustainable re-use for low-productive drained peatlands

LIFEPeatLandUse (LIFE12 ENV/FI/000150) 2013 – 2018, LAYMAN’S REPORT201

Trade-offs and synergies between biodiversity and ecosystem services in restored, reforested, abandoned, and energy-producing peatlands

There is a need to optimize the use of peatlands to simultaneously reach the biodiversity, environmental goals and the economic needs. Besides raw material timber and peat, peatlands provide a variety of valuable services, such as biodiversity, C sequestration and hydrological control. High pressure is targeted to these ecosystems by e.g. forest, bioenergy and peat industries. In Finland, a country with the highest percentage cover of peatlands in the world (30% of total land area, almost 10 mill. ha), about 60% of peatland area has been drained for forestry. This had led to the degradation of biodiversity, environmental loading to watercourses, and emission of greenhouse gases (GHG). We used empirical country-wide spatial data 1) to estimate and predict the impact of seven peatland uses on the biodiversity, GHG balances and environmental loading to watercourses, and 2) to numerically optimize cost efficient land uses so that benefits from biodiversity and ecosystem services are safeguarded. We show that there is no simple answer to the optimization of peatland uses due to the numerous trade-offs between biodiversity, ecosystem services and monetary value. The outcome depends on the level of environmental constraints, set monetary targets and the time frame of evaluation. Selection between multitude of options requires continuous contact between research, administration, planning, and other relevant stakeholders. We will demonstrate a multicriteria decision support tool that visualises the trade-offs and was piloted in a real planning case concerning peatland use.peerReviewe

Is 15 % restoration sufficient to safeguard the habitats of boreal red-listed mire plant species?

We used habitat suitability modeling to investigate whether the 15% ecosystem restoration target set in the previous Convention of Biological Diversity (CBD) and EU Biodiversity strategy targets, is sufficient to safeguard red-listed mire plant species. We assessed six theoretical restoration scenarios for drained peatland landscapes by altering the proportion of drained and undrained peatland area in 25-ha grid cells. The proportions represented steps when 15%, 30%, 45%, 60%, 75% and 100% of the drained peatland is restored. We modelled the habitat suitability for 48 red-listed plant species in the aapa mire region in boreal Finland. Model outcomes were assessed at the level of five species groups: calcareous species, rich fen species, decaying wood species, mesotrophic fen species, and spruce swamp species. The predicted distribution increased for 34 (71%) of the 48 red-listed plant species when 15% of drained peatland area was predicted to be restored. At the same time the potentially occupied area of species increased by 9%. In the scenario where all peatlands were restored, the predicted distribution of 43 (90%) of species increased, and on average the distribution of species quadrupled. According to our predictions, meeting the 15% ecosystem restoration target, set in the previous CBD and EU Biodiversity strategy targets would be beneficial for most of the boreal red-listed mire plant species, but a larger restoration area would expand their distribution considerably more. Our study shows that a landscape level approach is important to assess thresholds for the potential biodiversity benefits arising from peatland restoration. The models can also be used to select suitable areas for restoration

Boreal Picea abies mires of Finland: Cajanderian site types and compositional gradients in relation to species richness

201

Water quality management dilemma: Increased nutrient, carbon, and heavy metal exports from forestry-drained peatlands restored for use as wetland buffer areas

202

Trade-offs between economic returns, biodiversity, and ecosystem services in the selection of energy peat production sites

Economic development creates challenges for land-use planners in balancing between increasing the use of natural resources and safeguarding biodiversity and ecosystem services. We developed and utilized multi-objective numeric optimization models to analyze the trade-offs between biodiversity and ecosystem services (BES). The approach was used in the land-use planning process in northern Finland when selecting potential peat production sites as a part of the development of the regional master plan. We first quantified Net Present Value (NPV) of peat production, biodiversity, greenhouse gas (GHG) emissions, and water emissions of peatlands. Then we applied multi-objective optimization to examine the trade-offs between the variables as well as to determine a cost-efficient selection of potential peat production sites, that is, a selection which would simultaneously generate the greatest possible economic returns and environmental benefits. Our results showed that with a relatively small decrease in NPV, a substantial decrease in biodiversity loss and a reduction in water emissions compared to the benchmark level could be attained. However, a significant decrease in GHG emissions resulted in a substantial decrease in NPV. We conclude that it is possible to significantly improve land-use management by applying multi-objective optimization in land-use planning.Peer reviewe