Impact of elevated temperature and ozone on the emission of volatile organic compounds and gas exchange of silver birch (Betula pendula Roth)

Leaf anatomy, BVOC emission and CO2exchange of arctic plants following snow addition and summer warming

“…This may be due to a higher proportion of diffuse relative to direct solar radiation in OTCs (Leadley and Drake, 1993), which enhances photosynthetic efficiency in Arctic plant canopies (Williams et al, 2014). The observed higher P G is in agreement with B. pendula having greater photosynthesis at an elevated temperature (Riikonen et al, 2009;Hartikainen et al, 2012), but in contrast with a lack of OTC effects on B. nana net photosynthesis at saturating light after a 20-year-long experimental manipulation (Leffler et al, 2016). Evergreens seem even less responsive.…”

Increases in volatile organic compound emissions of Scots pine in response to elevated ozone and warming are modified by herbivory and soil nitrogen availability

“…The increased emissions reported here are in line with those from other juvenile boreal trees exposed to elevated temperature in the same exposure system (Hartikainen Kivimäenpää et al 2013). BVOC emission rates of Scots pine were less responsive to 1°C elevation in air temperature than those of broad-leaved trees Populus tremula (Hartikainen et al 2009) and Betula pendula (Hartikainen et al 2012) but much more responsive than those of another common conifer species, Picea abies ). Our hypothesis of increased BVOC emissions by elevated ozone was supported, and our results are in agreement with the findings of Heiden et al (1999) and Kivimäenpää et al (2013), showing that chronic ozone concentrations exceeding 40 ppb or the critical value, 5 ppm.h, of AOT40 ozone exposure for forest trees (Mills et al 2010) can increase BVOC emissions from boreal conifers.…”

“…Warming in general has increased BVOC emission rates of plants in field experiments lasting over growing season (Peñuelas and Staudt 2010). Elevated ozone concentrations, on the other hand, have either reduced or have had no influence on BVOC emission rates in most field experiments (Peñuelas and Staudt 2010;Hartikainen et al 2012;Llusia et al 2014). A few replicated long-term studies show opposite responses for Scots pine, i.e., reduced BVOC emissions under warming (Räisänen et al 2008) and increased emissions under ozone exposure (Heiden et al 1999).…”

Sensitivity of Norway spruce physiology and terpenoid emission dynamics to elevated ozone and elevated temperature under open-field exposure

“…Norway spruce is known to emit volatile organic compounds (VOCs) consisting mainly of terpenoids (isoprene, monoterpenes, sesquiterpenes) (Grabmer et al, 2006;Blande et al, 2009) that may influence atmospheric chemistry relevant to global climate change. For example, VOCs contribute to both formation and destruction of tropospheric ozone, which is a greenhouse gas and a phytotoxic agent, reduce the oxidation capacity of the atmosphere, and generally increases the VOC emissions from vegetation (Peñuelas and Staudt, 2010), which has been demonstrated in field conditions simulating climate warming (Tiiva et al, 2008;Hartikainen et al, 2009Hartikainen et al, , 2012bLlusià et al, 2009;Faubert et al, 2010), though not in all studies (Rinnan et al, 2011). A long-term field-chamber study by Räisänen et al (2008) revealed increased monoterpene emission rates from Scots pine (Pinus sylvestris) when elevated temperature and elevated CO 2 were combined, but elevated temperature alone decreased the VOC emissions.…”