The invasion of non-native plant species has a detrimental effect on native biodiversity. In a seven-year research project, we investigated the occurrence of the invasive species Asclepias syriaca ...L.in the Deliblato Sands protected area, located at a south-eastern part of the Pannonian Plain, and identified the factors that contribute significantly to its colonisation. The distribution of this invasive species was monitored on more than 300 km of the accessory, bordering and selected internal roads. A. syriaca occurs within the protected area but is much more widespread on accessory and bordering roads. The number of locations of A. syriaca increased every year of the study, even within the protected area, indicating a further spread of this species. A. syriaca is much more abundant on the north-eastern edge than in the south-west. The reason for this is most likely the much larger area of abandoned agricultural land in the north-east. Roads used for public transport are the main entry points for the further spread of A. syriaca. In contrast, recreational trail use does not enhance the spread in the Deliblato Sands natural reserve. This study can be used to further analyse the ecological dynamics of A. syriaca and to develop timely strategies by which to prevent or slow down its spread.
Blind mole rats (genus
) attract a great deal of attention because of their cancer resistance and longevity. Due to the high rate of chromosome rearrangements, 74
chromosomal forms have been ...discovered. The convergence of their external morphology complicates their taxonomy, and many cryptic species remain unrecognized. Thus, the European
supersp. is listed in the IUCN Red List of Threatened Species with "Data Deficient" status. It is crucial for the conservation of biodiversity to clarify its taxonomy, to recognize each cryptic species, and assign to them the correct conservation status. Of the more than 20 chromosomal forms described within
, five cryptic species occur in Serbia. The most threatened among them-
, described and named 50 years ago in the regions of Srem, Belgrade and Mačva-has been declared extinct in the literature, which may have negative consequences for the conservation of wildlife genetic diversity. Through five years of fieldwork and comparison of
and
gene segments between old, archived teeth and recently collected material, we show that
is not extinct. However, its habitat has been fragmented and reduced, owing primarily to anthropogenic impact. Therefore, detailed surveillance, population-structure studies, risk assessment, and appropriate conservation measures are needed.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Abstract
This is a preliminary and exploratory study of cranial variation in European populations of grayling. We investigated the correspondence between size/shape variation of the dorsal (dc), ...ventral (vc) and occipital (oc) cranium and phylogenetic relationships (inferred from mitochondrial control region - mtDNA cr and microsatellite dna data) of six grayling populations: three from Balkan phylogenetic clade and two from Caspian phylogenetic clade of the European grayling Thymallus thymallus and one population of the Adriatic grayling Thymallus aeliani, which until recently was considered the Adriatic phylogenetic clade of T. thymallus. Significant size and shape differences were found between populations in all three cranial views. However, significant size-related shape variation (allometry) was found for dc and vc, but not for oc. The size variation of each cranial view does not contain phylogenetic signal, but size variation of oc is consistent with genetic variation inferred from microsatellite dna. Regarding shape variation, a significant phylogenetic signal was detected only for oc, and only the shape variation of oc is consistent with the genetic variation inferred from the mtDNA cr. Moreover, the Adriatic grayling T. aeliani (Soča population) was clearly separated from the three T. thymallus populations of the Balkan phylogenetic clade and the two T. thymallus populations of the Caspian phylogenetic clade only at the level of oc. Thus, our results suggest that different cranial regions differ in allometry, reflect phylo(genetic) relationships differently, and exhibit differences in ecophenotypic plasticity, with oc seeming best suited to represent the phylogenetic relationships of the grayling populations studied.
A plant’s main mechanism to diminish the effects caused by high free radical levels generated during high irradiance is the synthesis of various secondary metabolites. In addition to interspecies ...differences, their concentrations may be influenced by genetic, ontogenic, morphogenetic or environmental factors. We investigated the influence of genetic (genotypes from different natural habitats) and environmental (contrasting light regimes as well as successive parts of the vegetation period) variability on the accumulation of 10 selected phenolic compounds (phenolic acids, flavonoids, and xanthones) in Iris variegata genotypes. Genotypes originated from either sun-exposed or shaded natural habitats were transplanted to two experimental light treatments (high light intensity with a higher R/FR ratio and low light intensity with a lower R/FR ratio). Significant impacts of both genetic and environmental seasonal variability (spring, summer and fall during the vegetation period) on phenolic compound profiles were detected. Their highest amounts were detected in spring. The magnitude of difference between light treatments (high vs. low light intensity) and the direction of this change varied depending on the secondary compound class. Phenotypic correlations among the 10 analyzed secondary metabolites differed across the experimental light treatments and their number decreased from spring to fall.
Phenotypic correlations were calculated and the levels of phenotypic integration of three congeneric species, annual Lamium purpureum and perennial Lamium album and Lamium maculatum, were estimated. ...Calculations were performed separately for different stages of development during transplantation under different density and light treatments. L. purpureum exhibited greater integration in comparison to the other two species before exposure to environmental treatments, as well as greater variability in phenotypic correlations in response to light and density. The perennial species possessed similar correlation patterns in comparison to annual L. purpureum, becoming more similar to L. purpureum at later stages of development. The effects of density and light intensity were dependent on the specific combination of factors, as well as on the species under study. Density effects in L. purpureum were also habitat- and population-specific. A greater difference in response to density treatments between habitats than between populations was detected. Overall, phenotypes become more integrated during ontogeny, while dissimilarities in phenotypic correlations among species and between populations were more related to ecological than to phylogenetic differences.
In this study we compared the biomonitoring potential of various types of flower asymmetry indices in Iris pumila (Dwarf Bearded Iris). We chose 197 naturally growing clones from the arid steppe ...habitat in the largest sandy area in Europe (Deliblato Sands Nature Reserve), and we transplanted two replicates of each clone to a polluted highway site with a heavy traffic flow. After a period of acclimatization, lower levels of photosynthetic pigment concentrations and higher stomatal density and specific leaf area in transplants verified that the chosen highway site was indeed more stressful and therefore suitable for estimation of the flower asymmetry biomonitoring potential. We analyzed radially and bilaterally symmetrical flower structures (radial fluctuating asymmetry (RA) and bilateral fluctuating asymmetry (FA)) on three perianth parts—falls, standards, and styles—and calculated various asymmetry indices based on linear and geometric morphometrics. Despite utilizing a heavily polluted environment and fairly large sample sizes, only one asymmetry index was significantly higher on the polluted site with demonstrated stressful effects on utilized plants, indicating that flower asymmetry was not an efficient method for biomonitoring in the case of I. pumila RA and FA indices.
To better understand what directs and limits the evolution of phenotype, constraints in the realization of the optimal phenotype need to be addressed. That includes estimations of variability of ...adaptively important traits as well as their correlation structures, but also evaluation of how they are affected by relevant environmental conditions and development phases. The aims of this study were to analyze phenotypic plasticity, genetic variability and correlation structures of important Iris pumila leaf traits in different light environments and ontogenetic phases, and estimate its evolutionary potential. Stomatal density, specific leaf area, total chlorophyll concentration and chlorophyll a/b ratio were analyzed on I. pumila full‐sib families in the seedling phase and on the same plants after 3 years of growth in contrasting light conditions typical for ontogenetic stage in question. There was a significant phenotypic plasticity in both ontogenetic stages, but significant genetic variability was detected only for chlorophyll concentrations. Correlations of the same trait between different stages were weak due to changes in environmental conditions and difference in ontogenetic reaction norms of different genotypes. Ontogenetic variability of correlation structures was detected, where correlations and integration were higher in seedlings compared with adult plants 3 years later. Correlations were affected by environmental conditions, with integration being higher in the lower light conditions, but correlations between phases being stronger in the higher light treatment. These findings demonstrated that the analyzed traits can be selected and can mostly evolve independently in different environments and ontogenetic stages, with low genetic variability as a potentially main constraint.
The aims of this study were to analyze phenotypic plasticity, genetic variability and correlation structures of important Iris pumila leaf traits in different light environments and ontogenetic phases, and estimate its evolutionary potential. Ontogenetic variability of correlation structures was detected, where correlations and integration were higher in seedlings compared with adult plants 3 years later. Correlations were affected by environmental conditions, with integration being higher in the lower light conditions, but correlations between phases being stronger in the higher light treatment. These findings demonstrated that the analyzed traits can be selected and can mostly evolve independently in different environments and ontogenetic stages, with low genetic variability as a potentially main constraint.
In light of the increasing need for appropriate, cost-effective detection
methods of anthropogenic pollution, we evaluated the biomonitoring potential
of flower developmental instability (DI) on a ...widely planted decorative
species, Iris germanica, under in situ conditions. DI was measured by
fluctuating and radial asymmetries of parts of Iris germanica perianth (810
fall lengths and widths), from clones already growing in two distinct types
of habitats with contrasting levels of anthropogenic pollution: in unpolluted
(rural) areas, Novi Banovci, Stari Banovci and Belegis (flowers from 137
clones sampled), and in a polluted (urban) Belgrade metropolitan area
(flowers from 133 clones sampled). Our results revealed significantly higher
flower radial asymmetry in the polluted habitats compared to unpolluted ones
(for three out of four univariate indices, as well as both multivariate
ones), but failed to detect a similar effect on fluctuating asymmetry
indices. The results of our study therefore demonstrate the potential of DI
(when estimated by flower radial asymmetry) in Iris germanica as a
cost-effective biomonitoring method for in situ pollution detection based on
readily measurable flower parts and moderate sample sizes.
In this study, we analyzed fluctuating asymmetry (FA) of black locust (
Robinia pseudoacacia
) leaf traits as a measure of developmental instability in polluted and unpolluted habitats. We aimed to ...evaluate the potential of this method as a biomarker and its applicability on widely distributed species under in situ conditions. Leaf samples were taken from seven sites—three categorized as unpolluted (natural protected and rural) and four categorized as polluted covering the broad spectrum of intense pollution (industrial and traffic), from 1,489 individual trees in total. Results revealed significant differences in FA with expected higher values in polluted environments. Applicability of FA of
R. pseudoaccacia
leaf traits as a biomarker for testing potential pollution level, as well as the amount and distribution of sampling effort needed for its application, are discussed.
The amount and pattern of individual phenotypic responses to seasonal changes
in environmental conditions were determined in clones of Iris variegata
growing in differing light habitats. For the ...purpose of the study, 97 clonal
plants of the rhizomatous herb I. variegata that experienced different light
conditions in their two native habitats were selected: one along the top and
slope of sand dunes and one in woodland understories. Two fully expanded
leaves that had developed during spring, summer and fall in two consecutive
years were sampled from each of these clones. Six leaf traits affecting the
photosynthetic rate of a plant ? morphological (specific leaf area),
anatomical (stomatal density) and physiological (total chlorophyll
concentration, chlorophyll a/chlorophyll b ratio, carotenoid concentration,
chlorophyll a/carotenoid ratio) exhibited significant plastic responses in
the two different light habitats. To test whether these traits differ between
exposed and shaded habitats as well as during different vegetation periods,
we used the repeated model analysis of variance (ANOVA). Results of the
repeated ANOVA revealed statistically significant effects of year, habitat
and period of vegetation season. Patterns of changes during growing seasons
were year-specific for almost all analyzed traits.
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