scholarly journals Patterns in the alien flora of the Democratic Republic of the Congo: a comparison of Asteraceae and Fabaceae

2020 ◽  
Vol 153 (3) ◽  
pp. 373-389
Author(s):  
Farzaneh Bordbar ◽  
Pierre Meerts
Keyword(s):  
Alien Species ◽  
Native Species ◽  
Life Form ◽  
Democratic Republic ◽  
Geographic Origin ◽  
Life Forms ◽  
Trait Divergence ◽  
Native Flora ◽  
Alien Flora ◽  
Republic Of The Congo

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.

scholarly journals Alien plant invasions in Mediterranean habitats: an assessment for Sicily

2021 ◽  
Author(s):  
Riccardo Guarino ◽  
Milan Chytrý ◽  
Fabio Attorre ◽  
Flavia Landucci ◽  
Corrado Marcenò
Keyword(s):  
Alien Species ◽  
Native Species ◽  
Vascular Plant ◽  
Regional Scale ◽  
Plant Invasions ◽  
Life Forms ◽  
Habitat Specificity ◽  
Alien Plant ◽  
Alien Flora ◽  
The Impact

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.

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

2021 ◽  
Author(s):  
Ali Omer ◽  
Maha Kordofani ◽  
Haytham H. Gibreel ◽  
Petr Pyšek ◽  
Mark van Kleunen
Keyword(s):  
Alien Species ◽  
South Sudan ◽  
Plant Invasions ◽  
Life Forms ◽  
Alien Plants ◽  
African Countries ◽  
Alien Flora ◽  
Result Show ◽  
Perennial Herbs ◽  
Disturbed Habitats

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.

scholarly journals Improving Checklists of Alien Plants with Digitised Herbarium Collections: The Example of D.R. Congo (Africa)

2021 ◽  
Author(s):  
Farzaneh Bordbar ◽  
Pierre Meerts
Keyword(s):  
Alien Species ◽  
Plant Species ◽  
Field Work ◽  
Sampling Effort ◽  
Alien Plant Species ◽  
Alien Plant ◽  
Widespread Species ◽  
Native Flora ◽  
Alien Flora ◽  
Herbarium Collections

Abstract The Democratic Republic of the Congo (D.R. Congo) represents a striking gap of knowledge on alien plant species. In this paper, we use digitised herbarium collections to assemble a checklist of alien plant species in D.R. Congo and to examine patterns in the alien flora. The new checklist comprises 426 alien species i.e., 182 (42.5%) casuals, 244 (57.5%) naturalised of which 80 (19% of aliens) are invasive. Discrepancies with previous databases are discussed. For many species in previous databases, we failed to find evidence for occurrence outside cultivation. A total of 158 taxa were not included in previous lists, 44 of which are new to D.R. Congo. Considering the size of the country and its rich native flora, the alien flora of D.R. Congo does not appear to be species rich. The alien flora is particularly rich in Fabaceae (15%) and in annual species (36%). America is by far the most important source continent (65%) and the proportion of annuals of American origin is particularly large among the most widespread species. Invasive success is discussed in terms of residence time. The very low number of new species records after 1960 is most likely accounted for by decreasing sampling effort. The results illustrate how herbarium collections can be used to critically revise existing checklists of alien species in tropical Africa. Field work is urgently needed to improve coverage of recent introductions and to monitor the status of alien species, especially in protected areas and around botanic gardens.

scholarly journals Biodiversity conservation in cities: Defining habitat analogs for plant species of conservation interest

2019 ◽  
Author(s):  
M Itani ◽  
M. Al Zein ◽  
N. Nasralla ◽  
S. N. Talhouk
Keyword(s):  
Plant Species ◽  
Species Interactions ◽  
Native Species ◽  
Life Form ◽  
Landscape Management ◽  
Life Forms ◽  
Habitat Diversity ◽  
Green Spaces ◽  
Urban Habitat ◽  
Stepwise Method

AbstractUrban plant habitats have become primary drivers of species interactions. They consist of managed vegetation and spontaneous assemblages of native, naturalized, ornamental garden escapes, and invasive species. Our objective was to define urban habitat analogs for a plant species of conservation interest, Matthiola crassifolia, which has persisted in varying abundance in the Mediterranean city of Beirut.We adopted a stepwise method that integrates two vegetation assessments, floristics, and physiognomy. We placed seventy-eight quadrats (1m x 1m) in 12 study sites following a deliberate biased method to capture habitat diversity. In every quadrat, we performed taxonomic identification and recorded life form of each species. We pooled species that shared the same life form into categories and estimated area cover for each of these life forms. We performed TWINSPAN analysis on floristic data to identify species positively associated with M. crassifolia, and on life forms, to determine plant assemblages that promote optimal M. crassifolia representation. We then combined findings from both analyses to generate a description of urban habitat analogs suitable for M. crassifolia.The results revealed that urban habitat analogs favorable to M. crassifolia include green spaces dominated by palms, low-lying succulents, or by shrubs with scale-like leaves. On the other hand, spaces dominated by turf grass, canopy trees, or vegetation that produces significant litter were not favorable to M. crassifolia’s persistence. Based on these findings, we generated a plant palette of native and non-native species to design urban habitat analogs favorable to the persistence of M. crassifolia.Synthesis and applicationsThe application of this method can inform planting designs that yield suitable habitats for plants of conservation interest. It can also guide landscape management plans that seek to create or modify green spaces to optimize growing conditions for species of conservation interest. Depending on sites, and based on the information generated by the stepwise method, designers and managers may decide to exclude life forms of native or non-native species that do not support the growth of a species of conservation interest, or they may create an artificial habitat that is conducive to its persistence.

scholarly journals Darwin’s naturalization conundrum disentangled: the role of phylogenetic relatedness depends on the invasion stages

2021 ◽  
Author(s):  
Ali Omer ◽  
Trevor Fristoe ◽  
Qiang Yang ◽  
Mialy Razanajatovo ◽  
Patrick Weigelt ◽  
...  
Keyword(s):  
Alien Species ◽  
Southern Africa ◽  
Native Species ◽  
Phylogenetic Distance ◽  
Phylogenetic Relatedness ◽  
Native Flora ◽  
Invasion Stage ◽  
Adaptation Hypothesis ◽  
The Relationship

Abstract Darwin’s naturalization hypothesis predicts successful invaders to be distantly related to native species, whereas his pre-adaptation hypothesis predicts the opposite. It has been suggested that depending on the invasion stage (i.e. introduction, naturalization, and invasiveness), both hypotheses, now known as Darwin’s naturalization conundrum, could hold true. We tested this by analysing whether the likelihood of introduction for cultivation as well as subsequent stages of naturalization and invasion of species alien to Southern Africa are correlated with their phylogenetic distance to the native flora of this region. While species were more likely to be introduced for cultivation if they are distantly related to the native flora, the probability of subsequent naturalization was higher for species closely related to the native flora. Furthermore, the probability of becoming invasive was higher for naturalized species distantly related to the native flora. These results were consistent across three different metrics of phylogenetic distance. Our study reveals that the relationship between phylogenetic distance to the native flora and success of an alien species depends on the invasion stage.

scholarly journals A review of the diversity and impact of invasive non-native species in tropical marine ecosystems

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Parisa Alidoost Salimi ◽  
Joel C. Creed ◽  
Melanie M. Esch ◽  
Douglas Fenner ◽  
Zeehan Jaafar ◽  
...  
Keyword(s):  
Climate Change ◽  
Coral Reefs ◽  
Alien Species ◽  
Native Species ◽  
Marine Ecosystems ◽  
The Other ◽  
Seagrass Beds ◽  
Native Flora ◽  
Major Threat ◽  
The Status

AbstractTropical marine ecosystems are biologically diverse and economically invaluable. However, they are severely threatened from impacts associated with climate change coupled with localized and regional stressors, such as pollution and overfishing. Non-native species (sometimes referred to as ‘alien’ species) are another major threat facing these ecosystems, although rarely discussed and overshadowed by the other stressors mentioned above. NNS can be introduced accidentally (for example via shipping activities) and/or sometimes intentionally (for aquaculture or by hobbyists). Understanding the extent of the impacts NNS have on native flora and fauna often remains challenging, along with ascertaining when the species in question actually became ‘invasive’. Here we review the status of this threat across key tropical marine ecosystems such as coral reefs, algae meadows, mangroves, and seagrass beds. We aim to provide a baseline of where invasive NNS can be found, when they are thought to have been introduced and what impact they are thought to be having on the native ecosystems they now inhabit. In the appended material we provide a comprehensive list of NNS covering key groups such as macroalgae, sponges, seagrasses and mangroves, anthozoans, bryozoans, ascidians, fishes, and crustaceans.

Preliminary Data on Alien Flora from Oltenia – Romania

2013 ◽  
Vol 40 (1) ◽  
pp. 33-42
Author(s):  
Daniel Răduţoiu ◽  
Ion Stan
Keyword(s):  
Alien Species ◽  
Plant Species ◽  
Residence Time ◽  
Preliminary Data ◽  
Life Form ◽  
Alien Plant Species ◽  
Alien Plant ◽  
Vascular Flora ◽  
Alien Flora ◽  
Invasive Status

Abstract This paper presents the list of alien plant species from Oltenia (Romania). For each taxon we mentioned and analysed the life form, the invasive status and the residence time. The collected and presented data highlight the expansion of the area of some alien species not mentioned previously in this part of the country and also the presence of a new subspontaneous species in the vascular flora of Romania, namely Lagurus ovatus.

Interactions between Callitris above-ground biomass, species density and plant form in north-eastern New South Wales

2013 ◽  
Vol 61 (1) ◽  
pp. 73 ◽  
Author(s):  
John T. Hunter
Keyword(s):  
Native Species ◽  
Life Form ◽  
Soil Depth ◽  
Life Forms ◽  
Species Density ◽  
Above Ground Biomass ◽  
Ground Biomass ◽  
Local Species Richness ◽  
Reserve Network ◽  
Cypress Pine

Dense Callitris endlicheri (Parl.) F.M.Bailey (black cypress pine) and C. glaucophylla Joy Thomps. & L.A.S.Johnson (white cypress pine) stands are often viewed as problematic and thinning is often encouraged from a biodiversity perspective. In the present investigation, canonical correspondence analyses (CCAs) of 997 survey sites were undertaken within the public and private reserve network that contains a variety of above-ground biomass (AGB) of C. endlicheri and C. glaucophylla (as measured by diameter at breast height (DBH) and dispersion) and the evenness of the species distribution was undertaken. This was done to further dissect the effect of Callitris AGB on species density (richness per quadrat) of native and introduced species and on broad life-form groupings. Other landscape features such as altitude, physiography, drainage and soil depth were also included in analyses. C. endlicheri and C. glaucophylla grow in different biophysical locations in most instances and this was reflected in the results of the study. No level of AGB or clumping of C. endlicheri was found to affect species density of native or introduced taxa or the distribution of life-forms. Increasing AGB of C. glaucophylla had a positive effect on native species density. The species density of introduced taxa was also increased with an increase in C. glaucophylla AGB. The distribution of life-forms was significantly affected by an increase in Callitris AGB with a decrease in trees, shrubby taxa and hemi-parasites, although herbaceous species had a concomitant increase in number. There is no reason to thin dense Callitris stands to increase local species richness. However, because the distribution of life-form types is significantly affected by C. glaucophylla, there is a need to understand what is occurring in species replacements and what landscape mosaic of structural types is required for this species. It is likely that dense stands of Callitris are important, along with a variety of stand densities so as to maintain the highest regional diversity.

scholarly journals Ecological Characterization of Invasive Alien Species and Associated Abiotic Factors of Three Islands in the Pool Malebo in Kinshasa, Democratic Republic of the Congo

2021 ◽  
pp. 1-11
Author(s):  
Michael Tshibangu Mukendi ◽  
Henri Kunzi Mbale ◽  
Pisco Munkolo Menga ◽  
Masens-da-Musa Yung ◽  
Jean Meti Ntumba ◽  
...  
Keyword(s):  
Alien Species ◽  
Democratic Republic ◽  
Invasive Alien Species ◽  
Abiotic Factors ◽  
Simple Random Sampling ◽  
Pistia Stratiotes ◽  
Study Region ◽  
Congo River ◽  
Physico Chemical ◽  
Republic Of The Congo

Nowadays, invasive alien species are causing more and more environmental problems in several water bodies around the world, in Africa and in the Democratic Republic of the Congo. In October 2020, a floristic inventory was carried out around three islands of the Congo River (Molondo, Mipongo and Japon) at the Pool Malebo in Kinshasa. The study focused on the identification and behavior of alien species along with associated abiotic factors in the Malebo Pool of the Congo River in Kinkole, Kinshasa. The study used a simple random sampling design to select different sites where samples were collected after a direct observation. We collected invasive species in the middle of the Congo River and to achieve that, we used canoe depending on the location of each site. Recorded species were classified either alien species or invasive alien species according to the status in the study region. The identification of collected species was performed according to APG III. Seeing the way these species invade the environment and how they disturb the ecology of rivers, the physico-chemical characteristics of waters were measured between 8:00 am and 3:00 pm with the appropriate electronic probe for each parameter. For each parameter, the comparison between the sites was carried out using the ANOVA test with XLSTAT 2013 software. The findings show that 19 species have been identified as invasive alien species out of which, four were dominant, namely Echinochloa pyramidalis, Eichhornia crassipes, Salvinia molesta and Pistia stratiotes. Considering the physico-chemical parameters, no significant differences were observed for the temperature (F=0.42 and p=0.66), conductivity (F=1.55 and p=0.25) and turbidity (F=2.28 and p=0.14) for the three sites. While the pH (F=4.98; p=0.026; LSD=0.361), dissolved oxygen (F=12; p=0.001; LSD=3.65) and salinity (F=4.06; p= 0.04; LSD= 1.69) showed significant variation in the three sites. The formation of vegetation groups around these islands in the Congo River at the Pool Malebo in Kinshasa  would also be justified by the influence of these parameters.

Biogeography of island floras in the Great Lakes. II. Plant dispersal

1989 ◽  
Vol 67 (6) ◽  
pp. 1803-1820 ◽  
Author(s):  
J. K. Morton ◽  
E. H. Hogg
Keyword(s):  
Great Lakes ◽  
Alien Species ◽  
Plant Species ◽  
Native Species ◽  
Vascular Plant ◽  
Species Dispersal ◽  
Alien Plant ◽  
Plant Dispersal ◽  
Alien Flora ◽  
Nesting Sites

Experimental and observational data were used to determine the adaptations for dispersal in each of the 335 vascular plant species in the flora of Barrier Island, a typical limestone island in the Great Lakes. Most have adaptations for more than one mode of dispersal. Adaptations for dispersal by water were found in 211 species (63% of the flora), and by birds in 205 species (61% of the flora); only 22 species (6.5% of the flora) do not appear to have effective adaptations for dispersal by either of these means. The other three modes of dispersal to these islands are by wind (14% of plant species), dispersal across snow and ice (10%), and by man (6%). Alien species (23% of the flora) show greater dependence on birds (85% of the alien species) and man (12% of the alien species) for dispersal than do native species (54 and 5%, respectively). Sea gulls, particularly the Herring Gull (Larus delawarensis Ord.), are the major factor in the introduction of the alien flora. The heavily disturbed habitats created in the nesting sites of both Herring and Ring-billed (Larus argentatus Pontoppidan) gulls favour the persistence of many alien plant species on these islands.

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