A5076035328- Soil Carbon and Nitrogen Dynamics
- Atmospheric and Environmental Gas Dynamics
- Peatlands and Wetlands Ecology
- Fire effects on ecosystems
- Plant Water Relations and Carbon Dynamics
- Climate change and permafrost
- Soil and Water Nutrient Dynamics
- Soil and Unsaturated Flow
- Forest ecology and management
- Cryospheric studies and observations
- Atmospheric chemistry and aerosols
- Tree-ring climate responses
- Marine and coastal ecosystems
- Plant responses to elevated CO2
- Hydrology and Watershed Management Studies
- Botany and Plant Ecology Studies
- Climate variability and models
- Ecology and Vegetation Dynamics Studies
- Methane Hydrates and Related Phenomena
- Forest Ecology and Biodiversity Studies
- Geology and Paleoclimatology Research
- Indigenous Studies and Ecology
- Coastal wetland ecosystem dynamics
- Rangeland and Wildlife Management
- Microbial Community Ecology and Physiology
University of Eastern Finland
2016-2025
Finland University
2016-2024
University of Helsinki
2009-2022
Marymount University
2020
Joint Research Centre
2018
University of Nebraska–Lincoln
2018
Mediterranean Center for Environmental Studies
2018
Université Toulouse III - Paul Sabatier
2018
Institute of Agrophysics, Polish Academy of Sciences
2018
Metsähallitus (Finland)
2010-2014
Abstract This paper discusses the advantages and disadvantages of different methods that separate net ecosystem exchange (NEE) into its major components, gross carbon uptake (GEP) respiration ( R eco ). In particular, we analyse effect extrapolation night‐time values daytime; this is usually done with a temperature response function derived from long‐term data sets. For analysis, used 16 one‐year‐long sets dioxide measurements European US‐American eddy covariance networks. These sites span...
Abstract The European CARBOEUROPE/FLUXNET monitoring sites, spatial remote sensing observations via the EOS‐MODIS sensor and ecosystem modelling provide independent complementary views on effect of 2003 heatwave biosphere's productivity carbon balance. In our analysis, these data streams consistently demonstrate a strong negative anomaly primary during summer 2003. FLUXNET eddy‐covariance indicate that drop in was not primarily caused by high temperatures (‘heat stress’) but rather...
Soil moisture induced droughts are expected to become more frequent under future global climate change. Precipitation has been previously assumed be mainly responsible for variability in summer soil moisture. However, little is known about the impacts of precipitation frequency on moisture, either interannually or spatially. To better understand temporal and spatial drivers drought, 415 site yr measurements observed at 75 flux sites world wide were used analyze relationships between water...
Thirty‐three snowpack models of varying complexity and purpose were evaluated across a wide range hydrometeorological forest canopy conditions at five Northern Hemisphere locations, for up to two winter snow seasons. Modeled estimates water equivalent (SWE) or depth compared observations open sites each location. Precipitation phase duration above‐freezing air temperatures are shown be major influences on divergence convergence modeled the subcanopy snowpack. When considered collectively all...
Changes in climate, land use, and management impact the occurrence severity of wildland fires many parts world. This is particularly evident Europe, where ongoing changes use have strongly modified fire patterns over last decades. Although satellite data by European Forest Fire Information System provide large-scale statistics across countries, there still a crucial need to collect summarize in-depth local analysis understanding condition associated challenges Europe. article aims general...
Abstract We estimated annual net ecosystem exchange (NEE) of a chronosequence four Scots pine stands in southern Finland during years 2000–2002 using eddy covariance (EC). Net productivity (NEP) was growth measurements and modelled mass losses woody debris. The were 4, 12, 40 75 old. 4‐year‐old clearcut source carbon throughout the year combining low gross primary (GPP) with total respiration (TER) similar to forest stands. NEE clearcut, measured by EC, 386 g C m −2 . Tree negligible NEP...
Thinning is a routine forest management operation that changes tree spacing, number, and size distribution affects the material flows between vegetation atmosphere. Here, using direct micrometeorological ecosystem‐scale measurements, we show in boreal pine forest, thinning decreases deposition velocities of fine particles as expected but does not reduce carbon sink, water vapor flux, or ozone deposition. The decreased all‐sided leaf area index from 8 to 6, suggest redistribution sources...
Abstract In this study the high-frequency loss of carbon dioxide (CO2) and water vapor (H2O) fluxes, measured by a closed-path eddy covariance system, were studied, related correction factors through cospectral transfer function method calculated. As already reported other studies, it was found that age sampling tube is relevant factor to consider when estimating spectral fluxes. Moreover, time-dependent relationship between characteristic time constant (or response time) for ambient...
Abstract Chamber measurements of trace gas fluxes between the land surface and atmosphere have been conducted for almost a century. Different chamber techniques, including static dynamic, used with varying degrees success in estimating greenhouse gases (CO 2 , CH 4 N O) fluxes. However, all these certain disadvantages which either prevented them from providing an adequate estimate exchange or restricted to be under limited conditions. Generally, methods are relatively low cost simple...
• Although there is increasing evidence of the temporal correlation between photosynthesis and soil CO2 efflux, no study has so far tested its generality across growing season at multiple sites several time scales. Here, we used continuous (hourly) data applied series analysis (wavelet coherence analysis) to identify correlations lags efflux for three forests from different climates a grassland. Results showed existence multi-temporal periods that varied 1 16 d during seasons all sites....
ABSTRACT Forest fires are a common natural disturbance in forested ecosystems and have large impact on the microbial communities forest soils. The response of soil fungal to fire is poorly documented. Here, we investigated community structure function across 152-year boreal chronosequence using high-throughput sequencing internal transcribed spacer 2 (ITS2) region functional gene array (GeoChip). Our results demonstrate that was most diverse soon after declined over time. differences were...
We seek to understand how biophysical factors such as soil temperature (Ts), moisture (theta), and gross primary production (GPP) influence CO2 fluxes across terrestrial ecosystems. Recent advancements in automated measurements remote-sensing approaches have provided time series which lags relationships among variables can be explored. The purpose of this study is present new applications continuous efflux (F0) concentrations measurements. Here we explore variation Ts, theta, GPP (derived...
[1] Significant amounts of terrestrial carbon are processed in lakes and emitted into the atmosphere as CO2. However, due to lack appropriate measurements absolute role landscape sinks or sources CO2 is still uncertain. We conducted first long-term, ecosystem-level flux with eddy covariance technique a boreal lake within natural-state catchment covering 5 years. The aim was reveal natural level between its regional cycling. On average, ca 10% net ecosystem production surrounding old-growth...
Abstract Boreal forests comprise 73% of the world’s coniferous forests. Based on forest floor measurements, they have been considered a significant natural sink methane (CH 4 ) and source nitrous oxide (N 2 O), both which are important greenhouse gases. However, role trees, especially conifers, in ecosystem N O CH exchange is only poorly understood. We show for first time that mature Scots pine ( Pinus sylvestris L.) trees consistently emit from stems shoots. The shoot fluxes exceeded stem...
Lakes and other inland waters contribute significantly to regional global carbon budgets. Emissions from lakes are often computed as the product of a gas transfer coefficient, k 600 , difference in concentration across diffusive boundary layer at air–water interface. Eddy covariance (EC) techniques increasingly being used lacustrine flux studies tend report higher values for derived than approaches. Using results an EC study small, boreal lake, we modelled using boundary-layer approach that...