Giant invasive Heracleum persicum: Friend or foe of plant diversity?

Abstract

The impact of invasion on diversity varies widely and remains elusive. Despite the considerable attempts to understand mechanisms of biological invasion, it is largely unknown whether some communities’ characteristics promote biological invasion, or whether some inherent characteristics of invaders enable them to invade other communities. Our aims were to assess the impact of one of the massive plant invaders of Scandinavia on vascular plant species diversity, disentangle attributes of invasible and noninvasible communities, and evaluate the relationship between invasibility and genetic diversity of a dominant invader. We studied 56 pairs of Heracleum persicum Desf. ex Fisch.‐invaded and noninvaded plots from 12 locations in northern Norway. There was lower native cover, evenness, taxonomic diversity, native biomass, and species richness in the invaded plots than in the noninvaded plots. The invaded plots had nearly two native species fewer than the noninvaded plots on average. Within the invaded plots, cover of H. persicum had a strong negative effect on the native cover, evenness, and native biomass, and a positive association with the height of the native plants. Plant communities containing only native species appeared more invasible than those that included exotic species, particularly H. persicum. Genetic diversity of H. persicum was positively correlated with invasibility but not with community diversity. The invasion of a plant community by H. persicum exerts consistent negative pressure on vascular plant diversity. The lack of positive correlation between impacts and genetic diversity of H. persicum indicates that even a small founder population may cause high impact. We highlight community stability or saturation as an important determinant of invasibility. While the invasion by H. persicum may decrease susceptibility of a plant community to further invasion, it severely reduces the abundance of native species and makes them more vulnerable to competitive exclusion.

Genetic Diversity in Invasive Populations of Lupinus polyphyllus Lindl. and Heracleum sosnowskyi Manden.

“…Therefore, our results suggest that anthropogenic dispersal may be a major factor contributing to the successful invasion of L. polyphyllus and H. sosnowskyi , together with their individual characteristics, which include environmental tolerance, high fertility, phenotypic plasticity, cold resistance, and the ability to occupy new biotopes. Both species have turned into transformers and supplanted the native species, significantly reducing the diversity of biogeocenoses [ 65 , 68 ]. Thus, these species require further study to successfully control their invasion.…”

Latitudinal trends in the structure, similarity and beta diversity of plant communities invaded by Alternanthera philoxeroides in heterogeneous habitats

“…Lots of studies have showed that plant invasions greatly reduce the biomass, coverage, evenness, richness and diversity of native plant species ( Flory and Clay, 2010 ; Yuguda et al., 2022 ), and plant invasions also could cause a significant increase in the litter biomass of invaded communities, which further benefits for excluding native plants ( Gooden and French, 2014 ). Additionally, plant communities containing only native species have a higher invasibility than those that included alien species, and alien plants that have similar functional traits with natives are more easily to enter and dominate the native plant communities ( Gooden and French, 2015 ; Li et al., 2015 ; Rijal et al., 2017 ). Moreover, environmental changes may affect the invasion process, e.g., seedling survival rate and drought tolerance of the invasive species Pennisetum ciliare are all increased by combinations of drought and warming, while this synergistic effect decreases leaf respiration of the native accompanying species Heteropogon contortus and causes substantial carbon loss, which accelerates native plant death ( Ravi et al., 2022 ).…”

The taxonomic significance of ddRADseq based microsatellite markers in the closely related species of Heracleum (Apiaceae)

“…The ecological significance of the Heracleum in terms of the negative effect on the local biodiversity has recently been reported in its invasive range in northern Europe [7]. Beside its significant impact on ecosystem, various species of the plant are used for variety of purposes which include as a fodder crop, ornamental use, food additives like spices, and in pharmaceutical applications [8,9].…”