The Relationships of Habitat Conditions, Height Level, and Geographical Position with Fruit and Seed Traits in Populations of Invasive Vine Echinocystis lobata (Cucurbitaceae) in Central and Eastern Europe

Abstract

In climbing plants, fruits can be formed at different heights, depending on the height of external support. However, the effect of height on fruit and seed traits in invasive vines of Cucurbitaceae has not been intensively studied so far. In Europe, Echinocystis lobata, a North American member of Cucurbitaceae, is considered one of the most abundant invasive alien plants spreading in natural riparian forests, thickets, and tall herbs, whereas it is a rare species in urban woodlands. In this study, we tested the variability of selected fruit and seed traits of E. lobata in connection with habitat origin (natural, semi-natural, and anthropogenic), habitat type (using the EUNIS habitat classification), height (the distance between the fruit and the ground), and geographical position. The study was conducted in 2018 in 65 sites located in Latvia, Lithuania, Poland, and Slovakia. In each study site, a random sample of 10 fresh mature fruits of E. lobata was collected from subsequent 0.50 m intervals of height. The length, the width, and the weight of the fresh fruits, as well as the total number of seeds and number of undeveloped seeds per fruit, were examined. Moreover, the well-developed seeds from selected study sites were weighed. The statistical analysis showed the significant effect of habitat origin, habitat type, and height on most of the studied fruit and seed traits. The largest range of height (from 0.00 to 4.00 m) was observed in two types of habitats (F—heathland, scrub, and tundra; and G—woodland, forest, and other wooded land). The total number of seeds per fruit was positively correlated with the length, width, and weight of the fresh fruits. The fruits were a little heavier and bigger in natural habitats located in the northeast of the study area. The distribution of fruits at different heights may contribute to better dispersal of seeds by animals and wind, and may also better protect the seeds from being eaten by granivorous animals. The defence against seed-eating animals is expected to be stronger in semi-natural habitats, as well as on banks and shores of inland surface waters, where the seed production is the highest. The influence of seed traits on seed germination and seedling survival in various habitats and their importance in the invasiveness of E. lobata require further study.

Seed variability of Sisymbrium polymorphum (Murray) Roth (Brassicaceae) across the Central Palaearctic

“…In our opinion, the size of seeds depends rather on the local habitat and climatic condi- tions in which a given population grows. Many previous studies (Sultan 2000(Sultan , 2001Fried et al 2008;Skrajna et al 2013;Szymura and Szymura 2013;Kostrakiewicz-Gierałt et al 2022) confirm that the main factors affecting the growth and morphological variation of plants include: soil fertility, climate, topographical conditions or type of land use. S. polymorphum grows on various types of soil, i.e.…”

“…Seed shape is crucial in some taxonomic research and, next to sculpture, is one of the most constant characteristics of species (Gamarra et al 2007;Hadidchi et al 2020). Moreover, the biometric analysis of individuals from different localities covering a wide range provides objective data on a given taxon's morphological (as well as habitat and climatic) variability (Skrajna et al 2012;Rewicz et al 2017;Kostrakiewicz-Gierałt et al 2022). Such analyses help to determine the influence of various environmental factors on the phenotypic variability of plants and phylogenetic inference (Bacchetta et al 2011;Rewicz et al 2016).…”

Assessing the Invasion Risk of Humulus scandens Using Ensemble Species Distribution Modeling and Habitat Connectivity Analysis

“…Invasive climbing species may be even stronger competitors with a more successful invasion rate, thus their impact on habitats and biodiversity is a matter of serious ecological concern [ 67 ]. Echinocystis lobata is one of the most abundant invasive climbing species from Europe, spreading in natural riparian forests, thickets, and tall herbs [ 68 ]. Sicyos angulatus , another invasive liana in Europe, also prefers riparian habitats where the soils are wet and fertile [ 69 ].…”

Established stands of the highly invasive Echinocystis lobata on the Ramsar sites of the southern part of the Pannonian plain

“…Like other climbing plants, this species invests most of its energy in the production of additional leaves and reproduction. Its resistance to seed predators is high on the shores of inland surface waters (Kostrakiewicz-Gierałt et al 2022), such as the investigated areas of this study. Due to its adaptability and intense growth, it can suffocate other species, even trees up to the canopy (Silvertown 1985;Bagi & Böszörményi 2008;Dylewski et al 2018).…”

“…The wild cucumber is a strong competitor for light in Salicion albae R.Tx. and other plant communities (Kostrakiewicz-Gierałt et al 2022). In habitats where it is invasive and forms large populations, E. lobata affects the structure of native vegetation, reducing the habitat biodiversity, and is therefore called a structural parasite (Bagi & Böszörményi 2008;Zelnik et al 2020).…”