Changes in the Fluctuating Asymmetry of the Leaf and Reproductive Capacity of Betula pendula Roth Reflect Pessimization of Anthropogenically Transformed Environment

Elena Shadrina,Nina Turmukhametova

doi:10.3390/sym12121970

Abstract

We have estimated the reproductive capacity of Betulapendula Roth and its relationship with an integrated measure of developmental stability, i.e., fluctuating asymmetry (FA) of the leaf. On the territory of a city with moderate anthropogenic pollution, a change has been detected in the integrated fluctuating asymmetry (IFA) of the morphology of the female reproductive sphere and reproductive capacity of Betula pendula. In conditions of anthropogenic stress, the birch is observed to produce a large yield of fruits annually, which is not subject to year-to-year fluctuations. Morphological variety of size and shape of fruit-producing organs increases along the gradient of industrial and transport pollution; part of morphotypes of infructescences and seeds is characterized by lowered or zero capacity for reproduction determined by seed quality (germination energy and germination capacity). The statistical data processing involved correlation, Shapiro–Wilk test, Levene’s test, factorial ANOVA, Scheffe test, Kruskal–Wallis ANOVA, Mann–Whitney test, χ2 method. Analysis of IFA has allowed us to reasonably well assess the state of the plant organism and to characterize environmental quality. A negative correlation between IFA and quantitative parameters of the functions of the reproductive sphere of B. pendula (infructescence diameter, seed quality) has been found, and positive correlation with qualitative parameters (the number of morphs of infructescences and seeds, the share of rare morphs of infructescences). Pessimization of urban environment creates the conditions for an increase in the share of defective infructescences and non-germinating seeds; a compensatory mechanism for this is an increase in reproductive effort of B. pendula. The consistency of responses in the vegetative and reproductive spheres reflects the disturbances in developmental stability of plants in urban communities.

Highlights

The problem of environmental pollution and the response of living organisms to anthropogenic factors remain relevant
Grade II of fruit producing intensity designates a modest quantity of infructescences on a small number of branches of a specimen, mainly in the upper and middle parts of the crown, especially at its south side; grade III, the trees have an average number of infructescences arranged uniformly or in groups on a significant number of branches in the upper and middle parts of thecrown, especially at its south side
In the central park, we have recorded a greater intensity of fruit producing in the trees of B. pendula, which means that infructescences are arranged almost over the entire crown, especially at its south side

Summary

Introduction

The problem of environmental pollution and the response of living organisms to anthropogenic factors remain relevant. The use of instrumental methods for analysis of air quality or soil composition, in conjunction with plant bioindicative characteristics, allows one to obtain more detailed information on their response to exposure to pollutants and to assess environmental quality [1,2,3,4,5,6,7]. The possibility of using FA for assessment of environmental health derives from the fact that it responds to the cumulative effect of the stress, reflecting the disturbances in developmental stability of the organism. This raises the question how developmental stability is related to the population ability to reproduce itself

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Conclusion