An Overview of the Isoprenoid Emissions From Tropical Plant Species

Abstract

Terrestrial vegetation is the largest contributor of isoprenoids (a group of biogenic volatile organic compounds (BVOCs)) to the atmosphere. BVOC emission data comes mostly from temperate regions, and less is known about BVOC emissions from tropical vegetation, even though it is estimated to be responsible for >70% of BVOC emissions. This review summarizes the available data and our current understanding of isoprenoid emissions from tropical plant species and the spatial and temporal variation in emissions, which are strongly species-specific and regionally variable. Emission models lacking foliar level data for tropical species need to revise their parameters to account for seasonal and diurnal variation due to differences in dependencies on temperature and light of emissions from plants in other ecosystems. More experimental information and determining how emission capacity varies during foliar development are warranted to account for seasonal variations more explicitly.

Isoprene Emission under Climate Change Scenario in Southeast Asia

“…It is noteworthy that the significant increase of isoprene emission over MSEA in July was marked by the surface temperature which persists at 25 -30 ℃ during mid-century, 30 -34 ℃ afterwards, and increased PAR of more than 8 W m -2 . As mentioned in the literature insertion of Mu [85], the emission rate of isoprene from plant increases to better tolerate higher steady-state of temperature and higher cumulative exposure of solar radiation (especially in July or warmer season) [54,71,79]. Thus, the finding of this study on the relationship between isoprene and changing climate (temperature and PAR) is similar to the finding of the aforementioned prior and recent studies.…”

Emissions of isoprenoids from dominant tree species in subtropical China

“…Previous studies have demonstrated that the emission factor (E s ) is one of the most important factors that induces large gaps among different studies (Guenther et al, 2006(Guenther et al, , 2012Tsui et al, 2009;Leung et al, 2010;Zheng et al, 2010;Wang et al, 2011Wang et al, , 2016Wang et al, , 2017Situ et al, 2014;Li et al, 2020). For decades, a large number of field and laboratory measurements have been carried out worldwide to obtain E s of BVOCs, yet most measurements were conducted for temperate or boreal plants (Evans et al, 1982;Tarvainen et al, 2005;Helmig et al, 2006Helmig et al, , 2007Helmig et al, , 2013Guenther, 2013;Aydin et al, 2014;Mu et al, 2022). On a global scale, tropical trees account for about 18% of the forest area (Jardine et al, 2020), but they contribute approximately 70% of the total emissions of BVOCs and 80% of the emissions of isoprene and MTs (Guenther et al, 2012).…”

“…Apart from higher emission rates of BVOCs relative to temperate and boreal regions, tropical regions have richer vegetation diversity with more uneven spatial distribution, and emissions of BVOCs in the tropics may have stronger spatial differences (Batista et al, 2019). However, to date, measurements of BVOC emissions from tropical trees are quite limited, and most of them were conducted in South America (the Amazon region), South Africa and India (Mu et al, 2022). In addition, due to limitations in measurement methods or experimental facilities, most field measurements for tropical trees only reported emissions of isoprene (Keller and Lerdau, 1999;Lerdau and Throop, 1999;Geron et al, 2002;Singh and Varshney, 2006;Singh et al, 2007Singh et al, , 2008, total MTs (Singh et al, 2011(Singh et al, , 2014 and total SQTs, and lacked emissions of individual MT and SQT compounds (Guenther et al, 1996;Klinger et al, 1998Klinger et al, , 2002Otter et al, 2002;Harley et al, 2003Harley et al, , 2004Varshney and Singh, 2003;Padhy and Varshney, 2005a,b;Jardine et al, 2020;Taylor et al, 2021).…”

Age effects of Moso bamboo on leaf isoprene emission characteristics

“…Environmental conditions generally exhibit apparent seasonal changes, with higher temperatures and light in summer and lower temperatures and light in winter. Inherent leaf capacity to synthesize isoprene may depend on the availability of the isoprene precursor and isoprene synthase activity, which are correlated with seasonal variations in isoprene emissions and are species-specific ( Kuhn et al., 2004 ; Mu et al., 2022 ). In this study, the isoprene emission rate was the highest in summer and the lowest in winter, which can be mainly attributed to environmental drivers such as temperature and light.…”

“…However, isoprene synthase activity strongly depends on the temperature ( Monson et al., 1992 ; Rasulov et al., 2010 ; Alves et al., 2014 ; Taylor et al., 2019 ). In addition, leaf phenology and physiology, nutrient and water availability, and even pre-measurement growth circumstances may all have a role in seasonal fluctuations ( Sharkey and Loreto, 1993 ; Alves et al., 2014 ; Mu et al., 2022 ).…”