Volatile Organic Compound Emissions from Prescribed Burning in Tallgrass Prairie Ecosystems.

Andrew R Whitehill,Kirk R Baker,Matthew Landis,Ingrid George,Russell Long

doi:10.3390/atmos10080464

Andrew R Whitehill, Kirk R Baker + Show 3 more

Open Access

https://doi.org/10.3390/atmos10080464

Copy DOI

Abstract

Prescribed pasture burning plays a critical role in ecosystem maintenance in tallgrass prairie ecosystems and may contribute to agricultural productivity but can also have negative impacts on air quality. Volatile organic compound (VOC) concentrations were measured immediately downwind of prescribed tallgrass prairie fires in the Flint Hills region of Kansas, United States. The VOC mixture is dominated by alkenes and oxygenated VOCs, which are highly reactive and can drive photochemical production of ozone downwind of the fires. The computed emission factors are comparable to those previous measured from pasture maintenance fires in Brazil. In addition to the emission of large amounts of particulate matter, hazardous air pollutants such as benzene and acrolein are emitted in significant amounts and could contribute to adverse health effects in exposed populations.

Highlights

Prescribed burning of grasslands plays a critical ecological and economic role in tallgrass prairie ecosystems, such as the Flint Hills range in Kansas, United States
Continuous timeseries of carbon monoxide (CO), CO2, and modified combustion efficiency (MCE) are shown in Figure 2, with raw data provided in the Supplemental Information (Tables S1–S4)
Canister CO data was used for all canister (VOC) analyses because the canister CO reflects the integrated sample collected during canister sampling, including any inconsistencies in sampling rates or spatial heterogeneities between the canister inlet and the gas phase inlets

Summary

Introduction

Prescribed burning of grasslands plays a critical ecological and economic role in tallgrass prairie ecosystems, such as the Flint Hills range in Kansas, United States. Fire-adapted non-equilibrium tallgrass ecosystems benefit from the removal of standing dead vegetation leading to improved sun and water penetration of the soil, the recycling of nutrients such as nitrogen, and the killing of competing plants such as forbs and woody vegetation [1,2,3]. Extensive studies have looked at the impact of the timing and frequency of prescribed burns on factors such as species ecology, biodiversity, soil moisture and nitrogen cycling, net ecosystem carbon dioxide (CO2 ) exchange, air quality, and other factors [4,5,6,7]. In the absence of natural fire events, prescribed burning at least once every three years is necessary to prevent the permanent encroachment of woody plants and maintain the prairie ecosystem [5,8,9]. Emitted volatile organic compounds (VOCs) react in the troposphere to form O3 in the presence of nitrogen oxides (NOx ), especially when meteorological conditions are favorable

Objectives

Methods

Results

Conclusion