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Jaan Pärn

Bio: Jaan Pärn is an academic researcher from University of Tartu. The author has contributed to research in topics: Peat & Soil water. The author has an hindex of 9, co-authored 26 publications receiving 529 citations. Previous affiliations of Jaan Pärn include University of Birmingham & Keele University.

Papers
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Journal ArticleDOI
TL;DR: In this article, the authors examined the evolution of European land management over the past 200 years with the aim of identifying key episodes of changes in land management, and their underlying technological, institutional and economic drivers.

233 citations

Journal ArticleDOI
TL;DR: In this paper, the authors reviewed the factors of transport from upland source areas to surface water as N and P indicators, and reported on the magnitudes of nutrients transfer and mitigate their environmental impacts using freshwater wetlands and riparian buffers.

134 citations

Journal ArticleDOI
TL;DR: In a global field survey across a wide range of organic soils, the authors find that N2O flux can be predicted by models incorporating soil nitrate concentration (NO3–), water content and temperature.
Abstract: Nitrous oxide (N 2 O) is a powerful greenhouse gas and the main driver of stratospheric ozone depletion. Since soils are the largest source of N 2 O, predicting soil response to changes in climate or land use is central to understanding and managing N 2 O. Here we find that N 2 O flux can be predicted by models incorporating soil nitrate concentration (NO 3 −), water content and temperature using a global field survey of N 2 O emissions and potential driving factors across a wide range of organic soils. N 2 O emissions increase with NO 3 − and follow a bell-shaped distribution with water content. Combining the two functions explains 72% of N 2 O emission from all organic soils. Above 5 mg NO 3 −-N kg −1 , either draining wet soils or irrigating well-drained soils increases N 2 O emission by orders of magnitude. As soil temperature together with NO 3 − explains 69% of N 2 O emission, tropical wetlands should be a priority for N 2 O management.

107 citations

Journal ArticleDOI
TL;DR: Conclusively, stem fluxes of CH4 and N2O are essential elements in forest carbon and nitrogen cycles and must be included in relevant models.
Abstract: One of the characteristics of global climate change is the increase in extreme climate events, e.g., droughts and floods. Forest adaptation strategies to extreme climate events are the key to predict ecosystem responses to global change. Severe floods alter the hydrological regime of an ecosystem which influences biochemical processes that control greenhouse gas fluxes. We conducted a flooding experiment in a mature grey alder (Alnus incana (L.) Moench) forest to understand flux dynamics in the soil-tree-atmosphere continuum related to ecosystem N2O and CH4 turn-over. The gas exchange was determined at adjacent soil-tree-pairs: stem fluxes were measured in vertical profiles using manual static chambers and gas chromatography; soil fluxes were measured with automated chambers connected to a gas analyser. The tree stems and soil surface were net sources of N2O and CH4 during the flooding. Contrary to N2O, the increase in CH4 fluxes delayed in response to flooding. Stem N2O fluxes were lower although stem CH4 emissions were significantly higher than from soil after the flooding. Stem fluxes decreased with stem height. Our flooding experiment indicated soil water and nitrogen content as the main controlling factors of stem and soil N2O fluxes. The stems contributed up to 88% of CH4 emissions to the stem-soil continuum during the investigated period but soil N2O fluxes dominated (up to 16 times the stem fluxes) during all periods. Conclusively, stem fluxes of CH4 and N2O are essential elements in forest carbon and nitrogen cycles and must be included in relevant models.

37 citations

Journal ArticleDOI
TL;DR: In this paper, the authors compared greenhouse gas emissions in natural and managed peatlands to examine the effect of management on GHG emissions and identify the environmental parameters affecting them, and found that intensive peatland management alters the soil C/N balance, and increases and leads to higher variability of emissions.

32 citations


Cited by
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Journal ArticleDOI
08 Oct 2020-Nature
TL;DR: A global N2O inventory is presented that incorporates both natural and anthropogenic sources and accounts for the interaction between nitrogen additions and the biochemical processes that control N 2O emissions, using bottom-up, top-down and process-based model approaches.
Abstract: Nitrous oxide (N2O), like carbon dioxide, is a long-lived greenhouse gas that accumulates in the atmosphere. Over the past 150 years, increasing atmospheric N2O concentrations have contributed to stratospheric ozone depletion1 and climate change2, with the current rate of increase estimated at 2 per cent per decade. Existing national inventories do not provide a full picture of N2O emissions, owing to their omission of natural sources and limitations in methodology for attributing anthropogenic sources. Here we present a global N2O inventory that incorporates both natural and anthropogenic sources and accounts for the interaction between nitrogen additions and the biochemical processes that control N2O emissions. We use bottom-up (inventory, statistical extrapolation of flux measurements, process-based land and ocean modelling) and top-down (atmospheric inversion) approaches to provide a comprehensive quantification of global N2O sources and sinks resulting from 21 natural and human sectors between 1980 and 2016. Global N2O emissions were 17.0 (minimum-maximum estimates: 12.2-23.5) teragrams of nitrogen per year (bottom-up) and 16.9 (15.9-17.7) teragrams of nitrogen per year (top-down) between 2007 and 2016. Global human-induced emissions, which are dominated by nitrogen additions to croplands, increased by 30% over the past four decades to 7.3 (4.2-11.4) teragrams of nitrogen per year. This increase was mainly responsible for the growth in the atmospheric burden. Our findings point to growing N2O emissions in emerging economies-particularly Brazil, China and India. Analysis of process-based model estimates reveals an emerging N2O-climate feedback resulting from interactions between nitrogen additions and climate change. The recent growth in N2O emissions exceeds some of the highest projected emission scenarios3,4, underscoring the urgency to mitigate N2O emissions.

650 citations

Journal ArticleDOI
TL;DR: In this article, the authors provide a systematic synthesis of 144 studies that identify the proximate and underlying drivers of landscape change across Europe and find that land abandonment/extensification is the most prominent (62% of cases) among multiple proximate drivers.

347 citations

Journal ArticleDOI
TL;DR: The authors reviewed and synthesized the theories that explain the causal mechanisms of land-use change, including systemic linkages between distant landuse changes, with a focus on agriculture and forestry processes.
Abstract: Changes in land systems generate many sustainability challenges Identifying more sustainable land-use alternatives requires solid theoretical foundations on the causes of land-use/cover changes Land system science is a maturing field that has produced a wealth of methodological innovations and empirical observations on land-cover and land-use change, from patterns and processes to causes We take stock of this knowledge by reviewing and synthesizing the theories that explain the causal mechanisms of land-use change, including systemic linkages between distant land-use changes, with a focus on agriculture and forestry processes We first review theories explaining changes in land-use extent, such as agricultural expansion, deforestation, frontier development, and land abandonment, and changes in land-use intensity, such as agricultural intensification and disintensification We then synthesize theories of higher-level land system change processes, focusing on: (i) land-use spillovers, including land sparing and rebound effects with intensification, leakage, indirect land-use change, and land-use displacement, and (ii) land-use transitions, defined as structural non-linear changes in land systems, including forest transitions Theories focusing on the causes of land system changes span theoretically and epistemologically disparate knowledge domains and build from deductive, abductive, and inductive approaches A grand, integrated theory of land system change remains elusive Yet, we show that middle-range theories – defined here as contextual generalizations that describe chains of causal mechanisms explaining a well-bounded range of phenomena, as well as the conditions that trigger, enable, or prevent these causal chains –, provide a path towards generalized knowledge of land systems This knowledge can support progress towards sustainable social-ecological systems

292 citations

Journal ArticleDOI
TL;DR: In this article, Sabatini et al. discuss the importance of gender diversity in soccer and discuss the role of gender in the sport of soccer in terms of sportswriting.
Abstract: Francesco Maria Sabatini1 | Sabina Burrascano2 | William S. Keeton3 | Christian Levers1 | Marcus Lindner4 | Florian Pötzschner1 | Pieter Johannes Verkerk5 | Jürgen Bauhus6 | Erik Buchwald7 | Oleh Chaskovsky8 | Nicolas Debaive9 | Ferenc Horváth10 | Matteo Garbarino11 | Nikolaos Grigoriadis12 | Fabio Lombardi13 | Inês Marques Duarte14 | Peter Meyer15 | Rein Midteng16 | Stjepan Mikac17 | Martin Mikoláš18 | Renzo Motta11 | Gintautas Mozgeris19 | Leónia Nunes14,20 | Momchil Panayotov21 | Peter Ódor10 | Alejandro Ruete22 | Bojan Simovski23 | Jonas Stillhard24 | Miroslav Svoboda18 | Jerzy Szwagrzyk25 | Olli-Pekka Tikkanen26 | Roman Volosyanchuk27 | Tomas Vrska28 | Tzvetan Zlatanov29 | Tobias Kuemmerle1

258 citations