Sewage Pollution Promotes the Invasion-Related Traits of Impatiens glandulifera in an Oligotrophic Habitat of the Sharr Mountain (Western Balkans)

An annual plant, Himalayan balsam (Impatiens glandulifera Royle) is globally widespread and one of Europe’s top invaders. We focused on two questions: does this species indeed not invade the southern areas and does the environment affect some of its key invisibility traits. In an isolated model mountainous valley, we jointly analyzed the soil (21 parameters), the life history traits of the invader (height, stem diameter, aboveground dw), and the resident vegetation (species composition and abundances, Ellenberg indicator values), and supplemented it with local knowledge (semi-structured interviews). Uncontrolled discharge of fecal wastewaters directly into the local dense hydrological network fostered mass infestation of an atypical habitat. The phenotypic plasticity of the measured invasion-related traits was very high in the surveyed early invasion (30–50% invader cover) stages. Different microhabitat conditions consistently correlated with its growth performance. The largest individuals were restricted to the deforested riparian habitats, with extreme soil nutrient enrichment (primarily by P and K) and low-competitive, species-poor resident vegetation. We showed that ecological context can modify invasion-related traits and what could affect a further invasion process. Finally, this species is likely underreported in the wider region; public attitude and loss of traditional ecological knowledge are further management risks.

Multitrophic Interactions Between Arbuscular Mycorrhizal Fungi, Foliar Endophytic Fungi and Aphids

Almost all living plants can be simultaneously colonised by arbuscular mycorrhizal fungi in the roots and endophytes in the shoots, while also being attacked by insect herbivores. However, to date, no study has ever examined the multitrophic interactions between these two different fungal groups and insects on any species of forb. Here, we examined the effects of two commercial species mixtures of arbuscular mycorrhizal fungi (AMF) and two foliar endophytes (Colletotrichum acutatum and Cladosporium oxysporum) on the growth of an invasive weed, Impatiens glandulifera, and the aphids that attack it. AMF reduced plant biomass, which was most evident when C. oxysporum was inoculated. Mycorrhizal fungi had few effects on aphids, and these depended on the identity of the endophytes present. Meanwhile, endophytes tended to increase aphid numbers, but this depended on the identity of the AMF inoculum. Throughout, there were differences in the responses of the plant to the two mycorrhizal mixtures, demonstrating clear AMF specificity in this plant. These specific effects were also strongly affected by the endophytes, with a greater number of interactions found between the AMF and endophytes than between the endophytes themselves. In particular, AMF reduced infection levels by the endophytes, while some endophyte inoculations reduced mycorrhizal colonisation. We suggest that both AMF and endophytes could play an important part in future biological control programmes of weeds, but further multitrophic experiments are required to unravel the complexity of interactions between spatially separated parts of the plant microbiome.

Geohistorical dataset of ten plant species introduced into Occitania (France)

The original dataset presented here is the result of the first near-exhaustive analysis performed on historical data concerning ten plant species introduced in and around Occitania (south-western France) since 1651. Research was carried out on the following species: Alnus incana, Buddleja davidii, Castanea sativa, Helianthus tuberosus, Impatiens glandulifera, Prunus cerasifera, Prunus laurocerasus, Reynoutria japonica, Robinia pseudoacacia and Spiraea japonica. The data file contains 199 occurrence data exclusively based on historical observations and records made between 1651 and 2004 and retrieved from 111 of the 640 literary sources consulted. All the records are associated with a year and 61% of them have associated spatial coordinates. Initially the EI2P-VALEEBEE research project focused on the introduction of these species into Occitania (95 occurrences, 47.7%), but mentions found beyond this territory - mainly in metropolitan France - are also reported. The creation of this dataset involved five stages: (1) selection of species, (2) consultation of historical sources, (3) recording of occurrences in the dataset, (4) dataset standardization/enrichment and Darwin core mapping, (5) data publication. Quality controls were conducted at each step. The dataset is available on the platform of the Global Biodiversity Information Facility (GBIF) at https://doi.org/10.15468/3kvaeh. It respects the internationally recognized FAIR Data Principles (Findable, Accessible, Interoperable and Reusable). The dataset will be progressively enriched by new data during the EI2P-VALEEBEE research project and future projects on invasive plant species conducted by the team.

Insect pests and their role as biocontrol agents on populations of Impatiens glandulifera in Bulgaria – a case study

Based on data from available scientific publications, a review of the insects, trophically related to Impatiens glandulifera in its European invasion zone has been made. As a result, nine insect species (Pristerognatha fuligana, Deilephila elpenor, Xanthorhoe biriviata, Chrysolina herbacea, Siobla sturmi, Impatientinum asiaticum, Aphis fabae, Aphis nasturtii, Phytoliriomyza melampyga) were found on the invasive plant. Of the identified insects, seven species (D. elpenor, X. biriviata, A. fabae, A. nasturtii, C. herbacea, P. fuligana, P. melampyga) are widespread in the country, of which only two – C. herbacea and  P. fuligana are associated with I. glandulifera. The remaining two (I. asiaticum and S. sturmi) are not pre-sented in the Bulgarian entomofauna. Тhe potential role of these insects as agents of biological control of populations of I. glandulifera in Bulgaria has been assessed.

Adventitious coastal-aquatic and aquatic plants - indicators of global climate warming

The paper describes the habitats of Vallisneria spiralis L., Impatiens glandulifera Royle, Pistia stratiotes L. discovered in recent years within the Samara Region. A brief review of the papers devoted to the migration activity of these plant species on the territory of the Russian Federation and the Volga basin is given. Impatiens glandulifera Royle is an annual hygrophyte. In the flora of the Samara Region it was first noted among local coastal plants in 2004 on one of the ponds of Samara on Mirnaya Street. The plant entered the reservoir from the adjacent garden plots of the private sector. Pistia stratiotes L. is an aquatic plant. In the flora of the Samara Region, a pistia was first found on September 17, 2006 in a city pond (near School № 154 of Samara) among thickets of Elodea canadensis Michx. and Typha latifolia L. growing at a depth of up to 50 cm. Vallisneria spiralis L. was first discovered within the Samara Region in September 2020. Long-term monitoring of the distribution of coastal-aquatic and aquatic macrophytes-migrants in the Middle Volga basin will allow us to more confidently attribute them to possible indicators of global and local climate warming and one of the examples when aquatic plant species move from south to north within the Volga basin.

Impacts of the Invasive Impatiens glandulifera: Lessons Learned from One of Europe’s Top Invasive Species

Biological invasions are renowned for their negative ecological and economic implications, however from studying invasions invaluable insights can be gained in the fields of ecology and evolution- potentially contributing towards conservation plans to deal, not only with biological invasion, but with other concerning issues, such as climate change. Impatiens glandulifera, or Himalayan balsam, is widely considered to be a highly problematic invasive, having spread across more than thirty countries during the past century. This paper will examine the findings which have arose from studying I. glandulifera and its impacts on the invaded ecosystem.