Physiological responses and accumulation of pollutants in woody species under in situ polluted condition in Southern China

Abstract

Physiological leaf traits and accumulation of pollutants of ten woody species in response to air pollution at seriously polluted site Sanguigang (SGG) and control site Maofengshan (MFS) in Southern China were studied. Net photosynthetic rates of most species at SGG were lower than those at MFS, but stomatal conductance (g(s)) showed opposite trend. The specific leaf area of Aporusa dioica, Sapium discolor, Schefflera octophylla and Toxicodendron succedaneum were significantly, 46.77, 13.09, 55.11 and 23.51 %, higher in SGG than in MFS, while chlorophyll content being the opposite. A. dioica had the highest sulphur (S) content at both sites (11.74 mg g(-1) at SGG and 11.07 mg g(-1) at MFS). Heavy metals concentrations were generally higher in species at SGG than at MFS. S. octophylla showed significantly higher concentrations of Zn, Cd and Mn (341.81, 2.41 and 2,287.29 μg g(-1)) than other species at SGG. Moreover, A. dioica had the highest Pb concentration (9.19 μg g(-1)), and L. glutinosa showed the highest Cr concentration (3.40 μg g(-1)). According to the integrated results, we infer that A. dioica, S. octophylla and L. glutinosa are the promising species for phytoremediation in the ceramic industry polluted environment.

Heavy Metal Contamination in Soils of Remnant Natural and Plantation Forests in an Urbanized Region of the Pearl River Delta, China

“…Although the mean total Mn concentration in all soils was lower than the background value, both total and extractable soil Mn concentrations were significantly higher in the industrial than in the non-industrial locations (Table 4 and Figure 2), suggesting the possibility of Mn contamination of the soils in the industrial locations. This result was consistent with a previous study in which foliar Mn concentrations for 10 woody species were higher in an industrial location than in a non-industrial location in the study area [20]. Close relationships of soil Mn concentrations with soil Pb and Cu concentrations ( Figure 4 and Table 6) also suggest that soil has been contaminated with Mn in the study area, given that soil Pb and Cu concentrations appear to have been significantly influenced by exogenous sources.…”

“…A recent study showed that particulate matter with a diameter <2.5 μm (PM 2.5 ) in the PRD, especially in Foshan, contained >1. For the non-industrial locations, total soil Zn concentrations (121.9-344.4 mg/kg) were markedly higher than the background value for Guangdong Province (47.3 mg/kg) (Table 4), a finding that agrees with previous reports [20,22]. In another previous study, the rate of atmospheric deposition was found to be five to 111 times higher for Zn (3740-6440 ng/m 3 ) than for Cu (34-914 ng/m 3 ) or Pb (147-995 ng/m 3 ) in this area [8].…”

“…With rapid urbanization and industrialization, however, large areas of natural lands in the PRD have been converted into farmlands or urban areas [16,17]. At the same time, various harmful substances, including acid precursors and heavy metals, have been emitted into the environment [7,17,18] and have increasingly impacted the remnant forests in this area [19][20][21]. Previous studies reported that heavy metals in forest soils were generally higher in the urbanized (or industrialized) areas than in the rural (or non-industrialized) areas of the PRD [20,22].…”

“…At the same time, various harmful substances, including acid precursors and heavy metals, have been emitted into the environment [7,17,18] and have increasingly impacted the remnant forests in this area [19][20][21]. Previous studies reported that heavy metals in forest soils were generally higher in the urbanized (or industrialized) areas than in the rural (or non-industrialized) areas of the PRD [20,22]. However, it is still unclear how heavy metals in soils of remnant forests in the PRD and in other urbanized areas vary with site location, forest type, and soil depth.…”

An Approach to Obesity as a Cardiometabolic Disease: Potential Implications for Clinical Practice

“…So, lower circulating irisin levels have been associated with T2DM. In particular, obese subjects with T2DM present lower irisin levels than non-diabetics, which may contribute to increase IR in this subgroup [191]. One plausible explanation to this fact could be the lower abundance of PGC-1α in skeletal muscle, as patients with early-onset type 2 diabetes display abnormalities in the exercise-dependent pathway that regulates the expression of PGC-1α [192].…”