scholarly journals Isoprene and monoterpene emissions from alder, aspen and spruce short-rotation forest plantations in the United Kingdom

2021 ◽  
Vol 18 (8) ◽  
pp. 2487-2510
Author(s):  
Gemma Purser ◽  
Julia Drewer ◽  
Mathew R. Heal ◽  
Robert A. S. Sircus ◽  
Lara K. Dunn ◽  
...  

Abstract. An expansion of bioenergy has been proposed to help reduce fossil-fuel greenhouse gas emissions, and short-rotation forestry (SRF) can contribute to this expansion. However, SRF plantations could also be sources of biogenic volatile organic compound (BVOC) emissions, which can impact atmospheric air quality. In this study, emissions of isoprene and 11 monoterpenes from the branches and forest floor of hybrid aspen, Italian alder and Sitka spruce stands in an SRF field trial in central Scotland were measured during two years (2018–2019) and used to derive emission potentials for different seasons. Sitka spruce was included as a comparison as it is the most extensive plantation species in the UK. Winter and spring emissions of isoprene and monoterpenes were small compared to those in summer. Sitka spruce had a standardised mean emission rate of 15 µgCg-1h-1 for isoprene in the dry and warm summer of 2018 – more than double the emissions in 2019. However, standardised mean isoprene emissions from hybrid aspen were similar across both years, approximately 23 µgCg-1h-1, and standardised mean isoprene emissions from Italian alder were very low. Mean standardised total monoterpene emissions for these species followed a similar pattern of higher standardised emissions in the warmer year: Sitka spruce emitting 4.5 and 2.3 µgCg-1h-1 for 2018 and 2019, aspen emitting 0.3 and 0.09 µgCg-1h-1, and Italian alder emitting 1.5 and 0.2 µgCg-1h-1, respectively. In contrast to these foliage emissions, the forest floor was only a small source of monoterpenes, typically 1 or 2 orders of magnitude lower than foliage emissions on a unit of ground area basis. Estimates of total annual emissions from each plantation type per hectare were derived using the MEGAN 2.1 model. The modelled total BVOC (isoprene and monoterpenes) emissions of SRF hybrid aspen plantations were approximately half those of Sitka spruce for plantations of the same age. Italian alder SRF emissions were 20 times smaller than from Sitka spruce. The expansion of bioenergy plantations to 0.7 Mha has been suggested for the UK to help achieve net-zero greenhouse gas emissions by 2050. The model estimates show that, with such an expansion, total UK BVOC emissions would increase between <1 % and 35 %, depending on the tree species planted. Whereas increases might be small on a national scale, regional increases might have a larger impact on local air quality.

2020 ◽  
Author(s):  
Gemma Purser ◽  
Julia Drewer ◽  
Mathew R. Heal ◽  
Robert A. S. Sircus ◽  
Lara K. Dunn ◽  
...  

Abstract. An expansion of bioenergy has been proposed to help reduce fossil-fuel greenhouse gas emissions, and short-rotation forestry (SRF) can contribute to that expansion. However, SRF plantations could also be sources of biogenic volatile organic compound (BVOC) emissions, which can impact on atmospheric air quality. In this study, emissions of isoprene and 11 monoterpenes from the branches and forest floor of hybrid aspen, Italian alder and Sitka spruce stands in an SRF field trial in central Scotland were measured during two years (2018–2019) and used to derive emission potentials for different seasons. Sitka spruce was included as a comparison as it is the most extensive plantation species in the UK. Winter and spring emissions of isoprene and monoterpenes were small compared to those in summer. Sitka spruce had a standardised average emission rate of 15 μg C g−1 h−1 for isoprene in the dry and warm summer of 2018, more than double the emissions in 2019. However, standardised average isoprene emissions from hybrid aspen were similar across both years, approximately 23 μg C g−1 h−1 and standardised average isoprene emissions from Italian alder were very low. Average standardised total monoterpene emissions for these species followed a similar pattern of higher emissions in the warmer year: Sitka spruce emitting 4.5 μg C g−1 h−1 and 2.3 μg C g−1 h−1 for 2018 and 2019, aspen emitting 0.3 μg C g−1 h−1 and 0.09 μg C g−1 h−1 and Italian alder emitting, 1.5 μg C g−1 h−1 and 0.2 μg C g−1 h−1, respectively. In contrast to these foliage emissions, the forest floor was only a small source of monoterpenes, typically one or two orders of magnitude lower than foliage emissions on a unit ground area basis. Estimates of total annual emissions from each plantation type per hectare were derived using the MEGAN 2.1 model. The modelled total BVOC (isoprene and monoterpenes) emissions of SRF hybrid aspen plantations were approximately half those of Sitka spruce for plantations of the same age. Italian alder SRF emissions were 20 times smaller than from Sitka spruce. The expansion of bioenergy plantations to 0.7 Mha has been suggested for the UK to help achieve net-zero greenhouse gas emissions by 2050. The model estimates show that with such an expansion total UK BVOC emissions would increase between


BMJ ◽  
2020 ◽  
pp. m2322 ◽  
Author(s):  
Marco Springmann ◽  
Luke Spajic ◽  
Michael A Clark ◽  
Joseph Poore ◽  
Anna Herforth ◽  
...  

AbstractObjectiveTo analyse the health and environmental implications of adopting national food based dietary guidelines (FBDGs) at a national level and compared with global health and environmental targets.DesignModelling study.Setting85 countries.ParticipantsPopulation of 85 countries.Main outcome measuresA graded coding method was developed and used to extract quantitative recommendations from 85 FBDGs. The health and environmental impacts of these guidelines were assessed by using a comparative risk assessment of deaths from chronic diseases and a set of country specific environmental footprints for greenhouse gas emissions, freshwater use, cropland use, and fertiliser application. For comparison, the impacts of adopting the global dietary recommendations of the World Health Organization and the EAT-Lancet Commission on Healthy Diets from Sustainable Food Systems were also analysed. Each guideline’s health and sustainability implications were assessed by modelling its adoption at both the national level and globally, and comparing the impacts to global health and environmental targets, including the Action Agenda on Non-Communicable Diseases, the Paris Climate Agreement, the Aichi biodiversity targets related to land use, and the sustainable development goals and planetary boundaries related to freshwater use and fertiliser application.ResultsAdoption of national FBDGs was associated with reductions in premature mortality of 15% on average (95% uncertainty interval 13% to 16%) and mixed changes in environmental resource demand, including a reduction in greenhouse gas emissions of 13% on average (regional range −34% to 35%). When universally adopted globally, most of the national guidelines (83, 98%) were not compatible with at least one of the global health and environmental targets. About a third of the FBDGs (29, 34%) were incompatible with the agenda on non-communicable diseases, and most (57 to 74, 67% to 87%) were incompatible with the Paris Climate Agreement and other environmental targets. In comparison, adoption of the WHO recommendations was associated with similar health and environmental changes, whereas adoption of the EAT-Lancet recommendations was associated with 34% greater reductions in premature mortality, more than three times greater reductions in greenhouse gas emissions, and general attainment of the global health and environmental targets. As an example, the FBDGs of the UK, US, and China were incompatible with the climate change, land use, freshwater, and nitrogen targets, and adopting guidelines in line with the EAT-Lancet recommendation could increase the number of avoided deaths from 78 000 (74 000 to 81 000) to 104 000 (96 000 to 112 000) in the UK, from 480 000 (445 000 to 516 000) to 585 000 (523 000 to 646 000) in the USA, and from 1 149 000 (1 095 000 to 1 204 000) to 1 802 000 (1 664 000 to 1 941 000) in China.ConclusionsThis analysis suggests that national guidelines could be both healthier and more sustainable. Providing clearer advice on limiting in most contexts the consumption of animal source foods, in particular beef and dairy, was found to have the greatest potential for increasing the environmental sustainability of dietary guidelines, whereas increasing the intake of whole grains, fruits and vegetables, nuts and seeds, and legumes, reducing the intake of red and processed meat, and highlighting the importance of attaining balanced energy intake and weight levels were associated with most of the additional health benefits. The health results were based on observational data and assuming a causal relation between dietary risk factors and health outcomes. The certainty of evidence for these relations is mostly graded as moderate in existing meta-analyses.


2015 ◽  
Vol 9 (1) ◽  
pp. 288-302 ◽  
Author(s):  
Carly Whittaker ◽  
Nicola E. Yates ◽  
Stephen J. Powers ◽  
Tom Misselbrook ◽  
Ian Shield

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