Alien flora of Oman: invasion status, taxonomic composition, habitats, origin, and pathways of introduction

We present the first inventory and status assessment of the alien flora of Oman, mainly based on field data collected from 1998 to 2021. The study provides (i) a comprehensive account of alien vascular plant species occurring in the wild in Oman, with information on their taxonomic composition. For each species information is given on (ii) invasion status (casual, naturalized or invasive), biogeography, habitat and life-form characteristics, and pathways of introduction. Further, we (iii) explain the differences in the alien species composition in different parts of the country, and (iv) analyse the drivers of plant invasions in Oman. Out of the 111 alien species reported (7.7% of the total Oman vascular flora), 34 species are casuals and 77 naturalized; of the latter seven are considered invasive. The moderate number of alien plant species is likely a result of the country’s arid climate, with extremely high summer temperatures and low annual precipitation in most of its area, and the relatively long isolation of the country. The families richest in alien plant species are Fabaceae (17 species), Asteraceae (14 species) and Poaceae (12 species). More alien plants were found in northern Oman (82 species) than in southern Oman (60 species), and very few species are recorded from the central desert (7 species). The main habitats colonized were man-made habitats, either ruderal or agricultural. Most species alien to Oman are native to South America (49 species) or North America (43 species). This inventory provides a knowledge base for developing a national management strategy for alien vascular plants in Oman.

Invasive alien plants in Bangladesh: taxonomic inventory, impact assessment and management issues

The establishment of a database of naturalized species is the first step in understanding the development and spread of invasion, and serves as a stepping-stone for further detailed studies on the biology and impact of individual species on the ecosystem. Preliminary dataset for such a database of Bangladesh is provided here. The inventory of invasive alien flora comprises of 54 species from 48 genera and 24 families. 54% species originate from South America, 17% from Tropical Asia, Tropical Africa and North America - 5% each, Australia and the Mediterranean region - 2% each and China - 1%. With regard to life form representation, herbs constitute the largest share (63%), followed by trees (13%), shrubs (9%), climbers (8%) and grass (7%). Combating plant Invasive Alien Species (IAS) in Bangladesh is very difficult due to the absence of (1) a cataloged list of identified plant IAS, (2) properly carried out case studies on economic and ecological impacts, (3) unstructured programs on management efforts, (4) awareness campaigns and (5) and coordination between different nodal ministries and agencies. As combating IAS requires an integrated approach, all relevant departments must integrate their approaches, establish a national focal point, education and strictly monitor and implement legal instruments.

Alien (invasive) vascular plants in Slovakia – a story of successful plant immigrants

This article summarises the history of research into alien plants and plant communities in Slovakia (Central Europe). Earlier periods are reviewed briefly with reference to literature sources dealing with those periods more comprehensively. A milestone in the research was the publication of the Inventory of the alien flora of Slovakia in 2012 with a complete list of alien vascular plants. The last ten years are discussed more extensively in the article in four sections devoted to i) newly found alien plants, ii) distribution and habitat relations, iii) plant invasions, iv) citizen science based on the comprehensive excerption of literature sources. A list of 51 newly published alien taxa within the last ten years is also included with information on the year of their first occurrence in the wild in Slovakia.

The current status of the plant invasions in Belarus

This article provides a review of the current status of plant invasions in Belarus. As a result of this research into the alien flora between 2008 and 2020 a list of 52 invasive plant species that threaten biodiversity, human health, and economic has been compiled. About 300 taxa of non-native plants are currently classified as potentially invasive. The list of invasive plant species has been proposed in this article in accordance with trends in the invasive processes is the basis for the monitoring and management of plant invasions in Belarus. The preliminary data from the previous field seasons showed a significant increase in the population abundance and distribution of Swida alba, Rudbeckia laciniata and Artemisia abrotanum. Enrichment of the flora occurs due to the introduction of aggressive plants. Hybridization between native and alien plant species leads to the appearance of hybrids, which often have an invasive potential, and can invade not only disturbed habitats but also natural plant communities. The invasive properties, expansion, and aggressive behavior of these invasive plants of the alien flora of Belarus has led to significant, often irreversible, changes in the natural vegetation and vegetation cover. Invasive species such as Solidago canadensis, S. gigantea, Echynocystis lobata, Impatiens glandulifera are marked by rapid expansion over past decades, and Heracleum sosnowskyi, Solidago canadensis, S. gigantea, Echinocystis lobata, Impatiens parviflora, Acer negundo, Robinia pseudoacacia, Bidens frondosa, have invaded more recently.

FIRST ASCERTAINABLE RECORD OF LUDWIGIA PEPLOIDES FROM ROMANIA

Ludwigia peploides (Kunth) P.H.Raven - Floating primrose-willow - is native to wetlands of North, Central, and South America, and widely distributed across Africa, Australia, and Asia, and in Europe, where it is listed by EU Regulation no. 2016/1141 as an Invasive Alien Species (IAS) of Union concern. A photograph of the species from Romania taken in the Sai River Valley (Teleorman County) was published on the Facebook online platform in 2018. This first record, however, lacked further details on the observed specimen or any accompanying herbarium material that would ascertain its correct taxonomic assignation. By carrying out our own field surveys between October and November 2020 we hereby confirm the presence of the species Ludwigia peploides as a new addition to the Romanian alien flora. We identified many specimens occurring along the Sai River Valley, between Olteanca and Turnu Magurele localities. We further present preliminary data regarding the distribution, affected habitats, and population extent of Ludwigia peploides in the investigated area. Although several hypotheses can be proposed on the origin of this species in Romania, our current data cannot strongly support any of them. Plant specimens were deposited in the Herbarium collection of the D. Brandza Botanic Garden of the University of Bucharest (BUC).

Influence of invasive flora species on the ecosystem of the Russian Far East

For the first time, based on the revision of herbarium collections, the resettlement of alien flora faction species in the Far Eastern Federal District (FEFD) was divided into four stages. Of the 117 invasive species of the Far Eastern Federal District, 47 ones were registered for the first time before the construction of the Trans Siberian railway, i.e. at the turn of the 1900s, 30 - from 1900 to World War II, 29 - from 1940 to 1980, i.e. before the targeted study of the alien flora faction, and 11 - from 1980 to the present. The data on scientists who played a key role in the study of the flora of the Far Eastern Federal District is presented. Seven species are only beginning to invade natural plant communities, 88 species are actively invading natural plant communities and 22 species belong to the “transformers”, which actively invade themselves into natural and seminatural communities, change the physiognomy of ecosystems, disrupt succession links, forming large single-species dense stands and force out and (or) obstruct the reproduction of aborigine species.

Mexican Coastal Dunes: Recipients and Donors of Alien Flora

The invasion of natural communities by exotic plants, which may turn into invasive or potentially invasive, is one of the most severe known threats to biodiversity, and coastal dunes are among the most affected habitats. Mexico’s coastal dunes are abundant and contain high plant biodiversity but attempts to determine the occurrence and impact of exotic plants are absent. First, we explored the number of invasive plant species found on Mexican coastal dunes. Second, we analyzed if the coastal dune flora native from Mexico acts as a source of invasive species worldwide. We found the relevant spread of exotic plants towards and from Mexico, reaching high percentages: 5% of the coastal dune flora are considered exotic plants; this increases to 8.7% when only plants typical of the coastal dune environment are considered. The Mexican coastal dunes flora is also a relevant source of invasive plants affecting all continents. Furthermore, almost half of the 35 worst worldwide invasive plants (according to the Global Invasive Species Database GISD) grow on Mexican coastal dunes, most native to Mexico and invasive elsewhere. Indeed, the worldwide exchange of coastal dune flora between Mexico and the world seems massive, relevant and highlights the need for worldwide and countrywide management and control strategies.