scholarly journals The alien flora of Sudan and South Sudan: taxonomic and biogeographical composition

Author(s):  
Ali Omer ◽  
Maha Kordofani ◽  
Haytham H. Gibreel ◽  
Petr Pyšek ◽  
Mark van Kleunen

AbstractStudies on plant invasions depend on local and regional checklists of the alien flora. However, global overview studies have shown that some regions, including many African countries, remain understudied in this regard. To contribute to filling this gap, here we present the first checklist of alien plants of Sudan and South Sudan (the Sudans). We analysed the taxonomic and geographical composition of the species on this list. Our result show that of the 113 alien species in Sudans (99 in Sudan and 59 in South Sudan), 92 (81.4%) are naturalized and 21 (18.6%) are just casual aliens. The number of naturalized species represent 2.2% of the total flora of the Sudans (4096). The alien species belong to 44 families and 85 genera, and many of them are native to Southern America and Northern America (85.8%). Annual and perennial herbs are the prevailing life forms in the alien flora of the Sudans (68.1%), and, among the casual species, perennial herbs are underrepresented whereas woody tree species are over-represented. Alien plants of the Sudans are mostly used for medicinal and environmental purposes globally. The naturalized plants predominantly occur in man-made disturbed habitats, such as agricultural and ruderal habitats. This first overview of the alien flora of the Sudans should stimulate further research and recording of the alien flora to better understand the drivers and consequences of alien plants in the Sudans.

Koedoe ◽  
2012 ◽  
Vol 54 (1) ◽  
Author(s):  
Alfred Maroyi

Zimbabwe’s casual, naturalised and invasive alien plant species were analysed with regard to their habit, origin, mode or purpose of introduction and their invasion status in the country. This alien flora of 391 taxa belonged to 239 genera and 73 families, corresponding to 6.6% of the total flora of Zimbabwe. Of these, 153 (39.1%) plant species were casual aliens, 154 (39.4%) were naturalised and 84 (21.5%) were invasive species. Most invasions in terms of numbers of alien species were in the central and eastern parts of the country. Asteraceae (53 species), Poaceae (48 species) and Fabaceae sensu lato (49 species) families were prominent in all the floristic regions of the country. Annual and perennial herbaceous species formed the majority of life forms of the casual, naturalised and invasive alien flora of Zimbabwe. Genera with the highest number of alien species were Ipomoea with nine species, Acacia and Euphorbia with eight species each, Chenopodium and Senna with seven species each, Eucalyptus with six species, Oenothera, Physalis and Solanum with five species each. More than 49.6% of the alien plants in Zimbabwe originated primarily from South, Central and North America, followed by Europe (24.6%), Asia (23.8%), Africa (10.5%) and Australasia (5.9%).Conservation implications: This research provides baseline information and historical invasion patterns of casual, naturalised and invasive alien flora in Zimbabwe. This inventory is a crucial starting point in trying to understand and initiate the management of biological invasions. This is also important for monitoring new introductions and management of existing alien plants in Zimbabwe.


Author(s):  
Riccardo Guarino ◽  
Milan Chytrý ◽  
Fabio Attorre ◽  
Flavia Landucci ◽  
Corrado Marcenò

AbstractLevels of plant invasions in different habitat types were assessed in several regional studies, but few of them were from the Mediterranean. Here we compare the levels of vascular plant invasion across habitats and plant communities of Sicily. We used a large dataset of plant species presences/absences in vegetation plots to analyze the invasion patterns across habitats considering biogeography, life form and phenology of alien plants. Vegetation plots were classified based on the EUNIS classification of European habitats. The invasiveness of each species was expressed in terms of its absolute and percentage frequency. Representation of different life forms and phenological patterns was compared between alien and native species. The fidelity of alien species to individual habitats was calculated using the phi coefficient. Our analysis shows that annual and woody species are the most represented life forms in the alien flora of Sicily and that alien species tend to have a longer flowering period than the native species. The investigated habitats differed strongly in their level of invasion by alien species, ranging from 0 to 15.6% of aliens of all species recorded. Most of the habitats were colonized by very few alien species or completely lacked them, except for sandy coasts, naturally-disturbed riverbeds, and synanthropic habitats. It must be noted, however, that the number of alien species occurring in a given habitat does not relate to the severity of the impact of invasion in that habitat. Some habitats are invaded by few (or single) species, which attain a high cover, transforming the whole ecosystem. The habitat-based approach proved to be suitable for evaluating the habitat specificity and frequency of alien species at a regional scale, improving the capacity for risk assessment in different ecological contexts.


2020 ◽  
Vol 153 (3) ◽  
pp. 373-389
Author(s):  
Farzaneh Bordbar ◽  
Pierre Meerts

Background and aims – This work provides the first pattern analysis of the alien flora of the Democratic Republic of the Congo (D.R. Congo), using Asteraceae and Fabaceae as a case study. Methods – Based on herbarium collections, existing databases, and literature data, a database of 38 alien species of Asteraceae and 79 alien species of Fabaceae has been assembled. Patterns in the introduction pathway, phylogeny, life form, morpho-functional traits, geographic origin, and occurrence in D.R. Congo are explored. Key results – America is the main source continent in both families, but Asia is also an important donor of Fabaceae. Taxonomic spectrum discrepancies between the alien and the native flora reflect the continent of origin. Sixty-six percent of alien Asteraceae have been accidentally introduced, most of which being annual weeds of disturbed soil. In contrast, 90% of alien Fabaceae have been deliberately introduced for forestry, agriculture, or environmental purposes, most of which being phanerophytes. Traits were compared between pairs of congeneric alien and native species. For Asteraceae, a sharp discrepancy was found in the life form spectrum (aliens: mostly therophytes; natives: phanerophytes). For Fabaceae, alien species had larger leaves and larger pods compared to their native congeners. The number of specimens in collections was positively correlated with the time since the date of first collection for both families. The Guineo-Congolian region has the highest number of alien Fabaceae, while alien Asteraceae are overrepresented in the Zambezian region.Conclusions – Contrasting patterns between alien Asteraceae and Fabaceae in the flora of D.R. Congo in terms of life forms, trait divergence compared to the native flora, and occurrence, reflect the divergent biological attributes and relations to humans of the two families. The striking discrepancies between the two families call for analyses of patterns of alien flora at family level and warn against global generalisations.


2021 ◽  
Vol 9 (4) ◽  
pp. 23-31
Author(s):  
Jana Májeková ◽  
Ivan Jarolímek ◽  
Marica Zaliberová ◽  
Jana Medvecká

Abstract 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.


Bothalia ◽  
2012 ◽  
Vol 42 (2) ◽  
pp. 71-85 ◽  
Author(s):  
C. Carbutt

An ‘early detection’-based desktop study has identified 23 taxa as ‘current’ emerging invasive alien plants in the Drakensberg Alpine Centre (DAC) and suggests a further 27 taxa as probable emerging invaders in the future. These 50 species are predicted to become problematic invasive plants in the DAC because they possess the necessary invasive attributes and have access to potentially suitable habitat that could result in them becoming major invaders. Most of the ‘current’ emerging invasive alien plant species of the DAC are of a northern-temperate affinity and belong to the families Fabaceae and Rosaceae (four taxa each), followed by Boraginaceae and Onagraceae (two taxa each). In terms of functional type (growth form), most taxa are shrubs (9), followed by herbs (8), tall trees (5), and a single climber. The need to undertake a fieldwork component is highlighted and a list of potential study sites to sample disturbed habitats is provided. A global change driver such as increased temperature is predicted to not only result in extirpation of native alpine species, but to also possibly render the environment more susceptible to alien plant invasions due to enhanced competitive ability and pre-adapted traits. A list of emerging invasive alien plants is essential to bring about swift management interventions to reduce the threat of such biological invasions.


Author(s):  
Annette Patzelt ◽  
Petr Pyšek ◽  
Jan Pergl ◽  
Mark van Kleunen

AbstractWe 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.


2012 ◽  
Vol 40 (2) ◽  
pp. 14 ◽  
Author(s):  
Lina PODDA ◽  
Valerio LAZZERI ◽  
Olga MAYORAL ◽  
Gianluigi BACCHETTA

Alien plants colonization, due to the fast spreading of highly invasive taxa, is more and more a serious source of concerns for habitat and species conservation. Apart direct in situ intervention, it is of major importance to acquire the best and up to date knowledge about alien taxa that currently threaten the integrity of wild and valuable environments. In this light, here is presented the update to the checklist of alien vascular flora of the island of Sardinia (Italy) on the basis of the new findings, nomenclatural adjustments, and revision of diffusion status of alien taxa. The checklist at present, consists of 541 taxa (84 doubtful) which represent 17% of the whole flora of the island; 22 taxa are new to the island and 7 of them for Italy. Neophytes represent the majority of the whole alien flora (301, 66% of the total) and, in confront to archaeophytes, gather nearly all invasive taxa (54 vs 4). The new findings are all neophytes. Phanerophytes (42%) are the most representative biological form and Americas represents the region that mostly contributes to the Sardinian alien flora (33%). Further analysis highlights that, in terms of number of taxa, highly anthropically impacted environments such as synanthropic (36%) and agricultural (23%) are the eligible habitats for most of the alien species in Sardinia while coastal areas and wetlands, beyond hosting a lower number of taxa, are characterized by the relative highest number of invasives.


Author(s):  
Gertrūde Gavrilova ◽  
Māris Laiviņš ◽  
Agnese Priede ◽  
Anda Medene

Alien flora in the Lake Engure Nature Park This paper describes the alien vascular plant flora in the Lake Engure Nature Park, one of the most species-richest and diverse areas in Latvia. The review was based on the floristic inventories conducted in 1983-1989 and a field survey carried out in 2010. In total, 68 alien species (7.6% of the vascular plant flora in the nature park) were recorded, of which four had established in the period between both surveys. 22 species were recognised as adventive species and 46 as escaped species. Most of the alien species area concentrated in coastal villages, around human settlements, roadsides, coastal dunes and along streams discharging in the Lake Engure, thus mostly in transformed habitats. They are absent in most of the natural and semi-natural habitats. In comparison to the overall situation in Latvia, the Lake Engure Nature Park area is relatively little affected by plant invasions, most probably because large areas of natural and semi-natural habitats remain, since high naturalness of vegetation plays a significant role as a natural barrier hindering alien invasions.


2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Jesamine C. Bartlett ◽  
Kristine Bakke‐Westergaard ◽  
Ingrid M. G. Paulsen ◽  
Ronja E. M. Wedegärtner ◽  
Florian Wilken ◽  
...  

2019 ◽  
Vol 40 (2) ◽  
pp. 215-242 ◽  
Author(s):  
Pere Aymerich ◽  
Llorenç Sáez

This is an inventory of the vascular alien flora of Catalonia (northeastern Iberian Peninsula, Spain) updated to 2018, representing 1068 alien taxa in total. 554 (52.0%) out of them are casual and 514 (48.0%) are established. 87 taxa (8.1% of the total number and 16.8 % of those established) show an invasive behaviour. The geographic zone with more alien plants is the most anthropogenic maritime area. However, the differences among regions decrease when the degree of naturalization of taxa increases and the number of invaders is very similar in all sectors. Only 26.2% of the taxa are more or less abundant, while the rest are rare or they have vanished. The alien flora is represented by 115 families, 87 out of them include naturalised species. The most diverse genera are Opuntia (20 taxa), Amaranthus (18 taxa) and Solanum (15 taxa). Most of the alien plants have been introduced since the beginning of the twentieth century (70.7%), with a strong increase since 1970 (50.3% of the total number). Almost two thirds of alien taxa have their origin in Euro-Mediterranean area and America, while 24.6% come from other geographical areas. The taxa originated in cultivation represent 9.5%, whereas spontaneous hybrids only 1.2%. From the temporal point of view, the rate of Euro-Mediterranean taxa shows a progressive reduction parallel to an increase of those of other origins, which have reached 73.2% of introductions during the last 50 years. The most important way of introduction is gardening (58.0%), followed by agriculture and commerce, while forestry is marginal. Invasive taxa mainly come from gardening and trade, but the proportion of the latter that become invasive is higher (6.1% and 15.6%, respectively). Most of the established aliens are annual and perennial forbs, while other biological types are less represented. These two types are also dominant among the invasive alien species, although a notable increase of trees and climbers has been observed recently.


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