Taraxacum officinale (Asteraceae) in the urban environment: seasonal fluctuations of plant traits and their relationship with meteorological factors

Abstract

Plants can be used as effective bioindicators of the quality of the urban habitat. In this study, physiological traits were examined in plants growing outdoors, in the proximity of a road. All material was collected from robust, well-grown plants. All measurements were performed during the generative phase. Here, the evaluations of some gravimetric parameters (fresh weight, turgid weight, dry weight, water content, ash content) and physiological parameters (initial water content, mineral content, organic content, organic content/mineral content ratio, succulence, mineral deposition in tissues, tissues density, leaf relative water content, specific leaf area) were calculated for <em>Taraxacum officinale</em> from urban unmanaged areas, across the different seasons (winter, spring, summer, fall). One-way analysis of variance (ANOVA) was used to compare these traits in leaves, scapes, and roots. Initial water content and relative water content are good indicators of water status in <em>T. officinale</em>. With regard to succulence, its level was generally considerably lower in roots than in aboveground organs. The mineral content differed significantly among plant organs. For all the parameters analyzed, the most considerable seasonal differences were found in leaves. The Spearman correlations were calculated for the relations between plant traits. Mineral deposition in tissues is the most sensitive parameter, regardless of the organ. The data were subjected to Spearman correlation and linear regression analysis for each physiological parameter and some meteorological factors. The strongest association was generally found with the wind. Variations in the investigated parameters in roots and scapes are more associated with meteorological factors. <em>Taraxacum officinale</em> plants are able to tolerate urban conditions in proximity to a road. Plastic responses to environmental cues make the plant useful in biomonitoring the quality of the urban habitat.

Effect of vehicle emissions on the morphological and physiological changes of Taraxacum officinale web

“…The study of plant mass showed that only in the area with a high intensity of traffic (plot № 1) is there a relationship between the mass of plants and the intensity of movement (r=0.97), while in areas with an average intensity of movement r=0.61, and with a low r=0.55. Our results are confirmed by studies by (Ianovici, 2016), in which it is shown that dandelion is an indicator of the concentration of heavy metals in the immediate vicinity of a road with heavy traffic. The most vulnerable cell structures are chloroplasts.…”

“…With increasing distance from the road, the proportion of altered forms decreases (in the area with the most intensive traffic from 40% to 8%). It was also shown that, with an increase in aerotechnogenic load, the sizes and leaf blades of woody plants decrease, but the influence of meteorological factors on these parameters is also noted (Ianovici, 2016). Our studies of leaf lengths showed that there was no clear dependence of leaf length on traffic intensity and distance from the road.…”

“…A correlation was also shown between the leaf Cd and the total phenols of the leaf, cichoric and kaftaric acids, which indicates that phenolic metabolites act to protect dandelion from excess Cd (Kováčik et al, 2016); therefore, dandelion is an indicator plant for detecting cadmium pollution (Simon et al, 1996;Ligocki et al, 2011), but cannot be an indicator of pollution by Mn (Normandin et al, 1999). It is also noted that morphological changes in its vegetative organs are often associated with meteorological factors (Ianovici, 2016), what to consider when analyzing morphometric indicator of vegetative organs. The effect of automobiles on the reproductive activity of T. officinale was also studied, and a positive correlation with the number of seeds and a negative correlation with the mass of seeds were noted (Erofeeva, 2014).…”

Environmental Factors Determining the Accumulation of Metals: Cu, Zn, Mn and Fe in Tissues of Taraxacum sp. sect. Taraxacum

“…Also linear emission connected with traffic may result in the increased content of heavy metals in soil. Many studies (Cook et al 1994 ; Degórska 2013 ; Ewen et al 2009 ; Giacomino et al 2016 ; Ianovici 2016 ; Korzeniowska and Panek 2010 ; Krčmová et al 2009 ) have reported that urban dust collected in streets is contaminated with trace metals, for example: zinc (Zn) and copper (Cu). According to the reports of General Directorate of National Roads and Motorways ( https://www.gddkia.gov.pl ), traffic intensity on roads located in close vicinity of sampling sites is higher in Zakopane than in Siedlce (by more than 7500 vehicles a day).…”

“…increased mobility of some metals (Vega et al 2004 ). Some authors (Bini et al 2012 ; Ianovici 2016 ; Keane et al 2001 ) emphasize that factors affecting the accumulation of metals in dandelion leaves are complex and often other environmental factors, in addition to the metals content in the soil, are crucial, e.g. the content of nutrients in the environment (Bini et al 2012 ; Wielgolaski 2001 ).…”