DESIGNING OF AN AIR POLLUTION POTENTIAL INDEX TO MEASURE THE SENSITIVITY OF AIR QUALITY TO VEGETATION

Certain tree species can emit large amounts of volatile organic compounds (VOCs) that have important implications for ozone and aerosol air quality. However, this factor has never been accounted for in afforestation and reforestation activities around the world. This implies that afforestation and reforestation efforts aiming to improve the environment (through carbon sequestration and climate mitigation, erosion control, etc.) could have unexpected, negative impacts on air quality if the wrong tree species are planted in the wrong locations. This study aims at integrating considerations for air quality in afforestation and reforestation activities by developing and promoting an easy-to-understand and easy-to-implement air pollution potential (APP) index. The APP values are affected by not only the biogenic VOC emissions rates associated with various tree species but also the sensitivities of ozone and secondary organic aerosols (SOA) to biogenic VOCs which show large spatial and seasonal variations. The APP values (for ozone and aerosols, respectively) can be calculated by combining atmospheric chemistry models with observational data for biogenic VOC emission rates from various tree species. The APP index can effectively help the public, in particular the stakeholders of afforestation and reforestation projects so that optimized planting strategies (on what kinds of trees to plant and where to plant) can be developed to maximize the benefits from afforestation and reforestation activities.