Deicing Salt Pollution Affects the Foliar Traits and Arthropods' Biodiversity of Lime Trees in Riga's Street Greeneries

Abstract

Street greeneries and other green spaces within the urban matrix can potentially reduce air pollution and increase urban biodiversity. Yet, these services can be negatively affected by anthropogenic stress factors. In the boreo-nemoral zone, large amounts of salts are spread each year for deicing the pavement. To address the effect of deicing salt on street lines of lime trees and how this cascades up to influence the surrounding arthropod biodiversity, we compared heavily salt-polluted, and less polluted sites in the city of Riga, Latvia. We analyzed the impairment of foliar functions and development of aphid colonies using a common garden experiment. We found marked variation in the soil physico-chemical properties in polluted vs. unpolluted sites, and the overall composition of arthropod communities, considering their abundance together with their diversity, significantly responded to site contamination. In a common garden experiment, we also showed that the exposure to increased salt levels in the soil caused functional as well as structural injuries within foliage and slowed down the development of aphid colonies. Finally, the damage inflicted by the lime tree aphids, especially in unpolluted sites, was positively correlated to the production of mucilage in the leaves, suggesting herbivore-induced mucilage production in leaves. The effects of de-icing salts thus appeared to cascade up through the trophic chain and to negatively affect not only the trees but also the associated arthropod biota. These findings point at the necessity of a wider screening of plant species and cultivars that not only better tolerate anthropogenic stress but also promote the biodiversity in cities.

The importance of prenol lipids in mitigating salt stress in the leaves of Tilia × euchlora trees

“…Leaf damage is mainly caused by Cl − (Slabu et al 2009;Genc et al 2015). Salt stress can also increase the susceptibility of trees to pathogens (Munck et al 2010;Snieškienė et al 2016), but there have also been reports that salinity may reduce the number of aphids on linden leaves (Sienkiewicz-Paderewska et al 2017;Bouraoui et al 2019).…”

Minimizing Shadow Area in Mountain Roads for Improving the Sustainability of Infrastructures

“…The design of a linear work is carried out in three clearly differentiated phases. The first of these consists of the geometric fit of the floor plan: a succession of straight alignments and circular curves in the transition of which spirals are used, and curves characterized by a linear transition of the curvature [21]. The second phase fits the elevation layout through the succession of straight alignments linked with parabolic agreement curves (Equation ( 5)).…”

“…Although we report the benefit of the use of these products, they also have important drawbacks. Their use leads to serious damage to plants and trees up to a distance of 200 m from the treated roads [16][17][18][19][20][21][22].…”

Road traffic and landscape characteristics predict the occurrence of native halophytes on roadside verges

“…Increased soil salt content alters pH, nutrient availability, and causes osmotic stress, thereby altering vegetation composition and promoting the spread of stress-tolerant, halophytes 26 . Furthermore, it causes leaf damage to some tree species and have negative impacts on several arthropod communities 27 and environmental impacts can be recorded 30 m away from the road by water run-off 28 . De-icing salts have negative impact on freshwater and wetland flora, fauna and biogeochemistry 29 .…”