Gas exchange, BVOCs, tree growth, measurement methodology, technical development, boreal forests
Long term measurements of tree and forest floor gas exchange, including VOCs, using online measurement methods. Understanding the dynamics, dependency on environmental controls of gas exchange, especially VOCs.
Sub-canopy VOC emissions
I examined the effect of sub-canopy removal (undergrowth thinning) on the exchange of volatile organic compounds (VOCs) between the forest stand and the atmosphere. I also considered the impact of soil moisture, temperature, and photosynthetically active radiation on this relationship. Plant-released VOCs, in addition to their role in plant growth, reproduction, and defense, have important implications for the Earth’s atmosphere. Therefore, studying how sub-canopy removal affects plant VOCs emission is of practical and theoretical significance.
email: mohamadali.ahi[@]helsinki.fi
I am a physicist with a long standing experience in remote sensing at different scales, from proximal to space-based, exploiting the capabilities of hyperspectral data.
I have designed various instruments for measuring optical properties both in the laboratory and in the field. Mostly oriented towards vegetation monitoring in general, and in particular the remote sensing of chlorophyll fluorescence at leaf and canopy level.
My research has been mainly performed under the preparation of several ESA Earth Observation missions, but mostly focused on FLEX (the Fluorescence Explorer).
I am applying my experience to enhance the measuring capabilities of the Optics of Photosynthesis Laboratory (OPL) indoors (laboratory and greenhouse) and outdoors. I am a visiting researcher in University of Helsinki, but my main current affiliation is as post-doc researcher at the Mediterranean Environmental Research Centre (CEAM) from the Valencian regional government in Spain.
Terrestrial ecology, biogeochemistry of air-land interactions, ozone deposition, ozone scavenging
I have studied primarily ozone deposition to vegetation and the mechanisms behind the process and currently I am interested in the potential role of BVOCs and aerosol load in ozone scavenging. I am also involved in research on C and N cycling in high-mountain pastures in the Pyrenees, studying the role of plant diversity
Forest modelling under climate change, remote sensing
My PhD was about process-based modelling on forest under climate change.
Energy exchange, dissolved organic carbon, DOC production, boreal forest
I am interested in how phenology affects the processes related to energy exchange and how ecosystems differ in this respect.
In addition I model the production of DOC (Dissolved Organic Carbon) and its transport into stream water in a boreal forest. In developing the model, I use data collected from intensively researched catchments in Finland and Sweden. I am also interested in the biogeochemical processes linked to the DOC cycle and have done reserach on the role of photochemistry in the breakdown of DOC transported by big rivers.
I am an isotope biogeochemist with a background in soil and environmental chemistry. My current work focuses on understanding and distinguishing between the processes that lead to plant methane emissions. I also make, listen, and dance to music and try to spend as much time in nature as possible.
Forest Biomass and Carbon Sequestration, Forest ecosystem modelling
Carbon dynamics in forest soils, with special interest in disturbed (fire, wind, reindeer grazing, etc.) areas
My current projects include measuring the short and long term effects of forest fires on the stability of carbon pools in boreal forests, estimating carbon turnover on disturbed forest areas and studying the carbon neutrality of reindeer management.
Vegetation and nutrient cycling in subarctic forests
In my doctoral thesis, I studied how forests vegetation in the northern latitudes responds to climate change. I approached the topic by analyzing the relationships that the forest vegetation has with a) soil nutrients, and b) atmosphere.
I am currently working as a postdoc with Dr Yann Salmon on understanding the relationships between carbon and water in phloem transport. I am broadly interested in the relationships between tree establishment, growth and survival and water. I have worked extensively with sap flow data while pursuing my PhD in Canada, working on mine reclamation sites.
BVOC production and emissions from soil processes
Water availability, water-use efficincy, leaf gas exchange, VOCs
My main interest concerns forests and how trees respond to changes in climate. I am interested in what are the mechanisms behind the responses of trees to water availability and what kind of trade-off effects determine the water-use efficiency, nitrogen-use efficiency and carbon production. My current focus is on sink and source driven processes in plant physiology that affect leaf gas exchange, including volatile carbon and nitrogen compound emissions from leaves.
Ecosystem ecology, physical limnology
Phytoplankton ecology and nutrient, biomolecule and gas cycling
My research interests are in the microscopical-sized life forms of lakes, especially in phytoplankton, and their roles in aquatic food webs. Particularly I’m interested in mixotrophy, grazing and exudate release (e.g. volatile organic compounds, BVOC’s) which are closely related to nutrient, biomolecule and gas cycling. My previous research topics have included studies on phytoplankton community composition and primary production as well as using phytoplankton as a potential source of oil for biodiesel production.
Gas-phase nitrogen exchange, methane emissions, wetlands
Exchange of reactive gas-phase nitrogen compounds between atmosphere and vegetation and global modelling of methane emissions from wetlands.
Urban trees, soils and ecosystems, and urban ecosystem services
ORCID: 0000-0002-5762-6173
More information in research database TUHAT
Ecosystem ecology, Carbon and Nitrogen budgets of forest - peatland ecotone, Tropospheric ozone
I am studying the effects of drought on CO2, CH4, and N2O dynamics along a boreal forest/mire ecotone. The ecotone is an ecological tension between habitats. In forest/mire transition, below-ground features of poorly drained peatlands overlap with the above-ground features of well drained forests.
Greenhouse gas dynamics of forest/mire transitions are poorly known, because of the relatively narrow extent between forests and peatlands. Although in the scale of boreal forest, the forest/mire transition covers large areas. For example in Finland the forest/mire transition covers approximately 3.1 Million ha, or 14 % of the total forest area.
Greenhouse gas exchange, trees, soil, urban green areas, forests
Measurements of greenhouse gas (CH4, N2O, CO2) exchange of soil and trees. PhD on methane exchange of boreal forest and studied carbon sink in urban green areas.
Currently working at the Baltic Sea Action Group. I’ll be mostly working with carbon sequestration in agricultural soils, promoting soil science and expertize around it, and establishing and enhancing networks between the researchers, farmers and policy makers.
BVOC emissions, synthesis, storages, stem VOC's
My research focuses on volatile organic compound (VOC) emissions from boreal forests. I'm especially interested on the emissions from woody plant parts such as living tree stems and how they vary temporally and spatially. I also study how VOC synthesis, storages and emissions are linked to each other and how they change during the annual cycle.