Konstantin Svetlozarov Gavazov

2018 - to present: WSL, Switzerland; SNSF Ambizione research associate 2015 - 2017: CIRC Abisko, Umeå University, Sweden; Postdoc in permafrost ecology and climate change 2014 - 2015: WSL, Switzerland; Postdoc in peatlands ecology and biogeochemistry 2009 - 2013: École Polytechnique Fédérale de Lausanne, Switzerland; PhD in Ecology. 2006 - 2009: Vrije Universiteit Amsterdam, the Netherlands; MSc in Ecology 2002 - 2005: Jacobs University Bremen, Germany; BSc in Biological Sciences.

Above- and below-ground responses to experimental climate forcing in two forb species from montane wooded pastures in Switzerland

Alexandre Buttler, Konstantin Svetlozarov Gavazov

Mountain ecosystems are particularly threatened by ongoing climate change and the species composition of high elevation grasslands is already changing. An open research question is how these ecosystems will adapt to changes in their key environmental constraints. The responses of wooded pastures to experimental climate forcing were analysed in a transplantation experiment conducted downslope, along an elevational temperature and precipitation gradient on the lee side of Jura Mountains, Switzerland (up to +4.17 degrees C and -35% precipitation). To improve mechanistic understanding of biodiversity and biomass decreases in response to transplantation, changes in functional traits within foliage and roots of one ubiquitous (Taraxacum officinale) and one montane (Alchemilla monticola) perennial forb species were investigated. In consequence of transplantation, the two studied species raised their temperature optimum for CO2 assimilation and net photosynthesis yield from 20 to 30 degrees C. During cool periods, the highest rates of leaf gas exchanges were measured at the lower recipient sites. However, an opposite trend was observed during a spring drought and summer warm spell. Regarding the more integrative morpho-anatomical traits, Alchemilla primarily acclimated to warmer temperatures at the recipient sites with increased leaf and foliage rosette size. Missing xeromorphic and/or hydraulic adjustments in foliage and roots, its susceptibility to higher vapour pressure deficits and lower soil moisture availability was thus enhanced. Taraxacum showed adjustments to both warmer temperature and lower moisture availability, including reduced leaf size, lower hydraulic diameter of xylem vessels and theoretical specific hydraulic conductivity. The anticipated shift in the environmental conditions at high elevation, with reduced coldness limitation but increasingly constraining water economy, could thus become particularly demanding for montane species of wooded pastures. It may favour perennials with large phenotypic plasticity but leads to maladjustments and loss of the species which are more specifically adapted to montane conditions. Read the free Plain Language Summary for this article on the Journal blog.

WILEY2022

The Legacy Effects of Winter Climate on Microbial Functioning After Snowmelt in a Subarctic Tundra

Konstantin Svetlozarov Gavazov

Warming-induced increases in microbial CO2 release in northern tundra may positively feedback to climate change. However, shifts in microbial extracellular enzyme activities (EEAs) may alter the impacts of warming over the longer term. We investigated the in situ effects of 3years of winter warming in combination with the in vitro effects of a rapid warming (6days) on microbial CO2 release and EEAs in a subarctic tundra heath after snowmelt in spring. Winter warming did not change microbial CO2 release at ambient (10 degrees C) or at rapidly increased temperatures, i.e., a warm spell (18 degrees C) but induced changes (P

SPRINGER2019

Above- and below-ground responses to experimental climate forcing in two forb species from montane wooded pastures in Switzerland

Alexandre Buttler, Konstantin Svetlozarov Gavazov

WILEY2022

Konstantin Svetlozarov Gavazov

Above- and below-ground responses to experimental climate forcing in two forb species from montane wooded pastures in Switzerland

Drought-induced decline of productivity in the dominant grassland species Lolium perenne L. depends on soil type and prevailing climatic conditions

The Legacy Effects of Winter Climate on Microbial Functioning After Snowmelt in a Subarctic Tundra

Above- and below-ground responses to experimental climate forcing in two forb species from montane wooded pastures in Switzerland

Drought-induced decline of productivity in the dominant grassland species Lolium perenne L. depends on soil type and prevailing climatic conditions

The Legacy Effects of Winter Climate on Microbial Functioning After Snowmelt in a Subarctic Tundra