Seasonal variations of trace element contents in leaves and bark of horse chestnut (Aesculus hippocastanum L.) in urban and industrial regions in Serbia

Abstract

In this study, we examined the ability of horse chestnut (Aesculus hippocastanum L.) to capture heavy metals, and whether its capacity to absorb metals from soil is associated with surrounding ecological characteristics and sources of pollution. We studied the seasonal accumulation of B, Cu, Sr and Zn in leaves and bark, and the chlorophyll content in the common deciduous tree Aesculus hippocastanum L. in four urban parks in Pancevo, Smederevo, Obrenovac and Belgrade (Serbia) affected by different anthropogenic activities. The research included plants from a control site located within the zone of a former oak forest. Our findings suggest that there are potential ecological risks around Smederevo, Belgrade and Obrenovac due to elevated concentrations of B and Zn relative to the average concentrations described for worldwide soils, as well as national regulations. Substantial and toxic foliar accumulation of B was observed in Smederevo and Belgrade, and of Sr in both plant tissues at all sites. However, the Cu and Zn contents in leaves were not enough to meet the physiological needs of plants. Chlorophyll a and the total carotenoid content peaked in August under the most unfavorable conditions of the year, which may be considered as an adaptive mechanism. The obtained results showed the remarkable complexity of environmental conditions and the difficulties A. hippocastanum, as a species, has to overcome. Under conditions of different types of urban and industrial pollution, A. hippocastanum showed great element accumulation potential and could be regarded as both an accumulator and a response indicator, since its leaves are quite susceptible to damage. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 173018]

How does the content of nutrients in soil affect the health status of trees in city parks?

“…To conclude, even without exhaust gas emissions car traffic is still a significant source of particulate matter (PM) in urbanised areas [25, 26]. The accumulation of heavy metals in soils and plants growing in cities has been studied in various regions of the world [27–29]. This type of pollution of anthropogenic origin is usually caused by the emission of exhaust gases and by the industry.…”

Using Fractionation Profile of Potentially Toxic Elements in Soils to Investigate Their Accumulation in Tilia sp. Leaves in Urban Areas with Different Pollution Levels

“…tree and their associated soil from each sampling location were then mixed, resulting in one composite sample of Tilia sp. leaves and corresponding soil per sampling location [10,[55][56][57]. Samples were collected in June 2017.…”

“…Cities are becoming regional sinks for resource consumption and sources of chemical emissions which results in elevated concentrations of PTEs but also the deficiency of certain essential elements due to the changed balance of the biochemical and geochemical cycles of chemical elements in urban soils [7,8]. Particularly, urban soil plays a role of a scavenger agent and adsorption sink for PTEs because once introduced in the urban environment; they persist in soils over long periods [9][10][11][12]. Additionally, soils in urban areas often have a changed structure, physical and chemical characteristics, and low concentrations of essential elements [13].…”

Biological Flora of the British Isles:Aesculus hippocastanum

“… 1 Yilmaz et al (); 2 Petrova, Yurukova, and Velcheva (); 3 Aničić et al (), Kocić, Spasić, Urošević, and Tomašević (), Pavlović et al (); 4 Kim and Fergusson (). …”