Effects of Particulate Matter of Various Sizes Derived from Suburban Farmland, Woodland and Grassland on Air Quality of the Central District in Tianjin, China

Abstract

Poor air quality directly affects human health and has become an increasingly important environmental issue in Tianjin, China. The suspension of particulate matter (PM) in the atmosphere is not only from industrial pollutants, but also soil wind erosion; however, the contributions from farmland, woodland, and grassland have rarely been considered in this region. We conducted an assessment of PM sources through wind erosion, dust emission, and dust transportation from urban and rural areas to the central district in Tianjin, and our results demonstrated that the spatial variability of wind erosion and dust emission strongly depends on land use, particle size distribution and meteorological conditions. The equations in this study were empirical, and soil properties such as aggregation and crusting, as well as surface characteristics such as canopy height and residue cover, were not considered. The dust emission capacity of woodland and grassland was the lowest because of vegetation coverage. The values obtained in this study may overestimate emissions, because soil aggregation was not considered. The yearly dust amounts of PM [15][16][17][18][19][20] (particles with aerodynamic diameter from 15 µm to 20 µm), PM 10-15 (particles with aerodynamic diameter from 10 µm to 15 µm), and PM 10 (particles with aerodynamic diameter less than 10 µm) from wind erosion in 2009 from the urban area in Tianjin were estimated as 5,400 t, 5700 t and 17,300 t, respectively, while those from the rural area were 14,000 t, 15,300 t and 40,700 t, respectively. The dust emission contributed from farmland accounted for 99.5%, and that from woodland and grassland only accounted for 0.5%. The PM 10 transported to the central district and PM 10 concentrations in the days with the 20% highest PM 10 concentrations in the central district in 2009 were compared. The R 2 was 0.74, which meant the two variables were highly correlated.

Changes in CSR Ecological Strategies of Plants and Communities Following the Introduction and Restoration of Woody Plants in Semi-arid Damaged Steppe Grasslands

“…Grasslands provide important ecosystem services such as the role of a protective cover for soil, primary production, maintenance of the diversity of ecosystems, and biodiversity (Shantz, 1954;Eyre, 1968;Angerer et al, 2008;Wrage et al, 2011;Li et al, 2022). However, most grasslands are threatened by continuous overgrazing, conversion of farmlands, deforestation, and indiscriminate reclamation that would lead to severe declines of grasslands (Blair et al, 2014;Chen et al, 2012;Chen et al, 2014). At the same time, grassland ecosystems are being devastated due to decreases in precipitation due to climate change, continued forest res and drought, and deterioration of land conditions (Montanarella et al, 2018) (Blair et al, 2014).…”

Changes in Competitors, Stress Tolerators, and Ruderals (CSR) Ecological Strategies after the Introduction of Shrubs and Trees in Disturbed Semiarid Steppe Grasslands in Hulunbuir, Inner Mongolia

“…Grasslands provide important ecosystem services, such as providing protective cover for soil, primary production, maintenance of the diversity of ecosystems, and biodiversity [3][4][5][6][7]. However, most grasslands are threatened by continuous overgrazing, the conversion of farmlands, deforestation, and indiscriminate reclamation, which has led to a severe decline in grasslands [8][9][10]. At the same time, grassland ecosystems are being devastated by decreases in precipitation due to climate change, continual forest fires and drought, and the deterioration of land conditions [8,11].…”

Evaluation of Nine Operational Models in Forecasting Different Types of Synoptic Dust Events in the Middle East

“…Decreased horizontal visibility due to massive dust storms, causes traffic accidents and increases the death rate every year [14][15][16][17]. Furthermore, land degradation by wind erosion affects many parts of the world [18][19][20][21][22], and therefore, the occurrence of dust storms has destructive effects on crop growth, livestock production, agricultural infrastructure and ecosystem health [23,24].…”