Litter burning does not equally affect seedling emergence of native and alien species of the Mediterranean-type Chilean matorral

2009 ◽  
Vol 18 (2) ◽  
pp. 213 ◽  
Author(s):  
Susana Gómez-González ◽  
Lohengrin A. Cavieres
Keyword(s):  
Alien Species ◽  
High Intensity ◽  
Native Species ◽  
Seedling Emergence ◽  
Fire Intensity ◽  
Alien Plant ◽  
Central Chile ◽  
Ecological Features ◽  
Chilean Matorral ◽  
Anthropogenic Fires

Central Chile differs from other areas with Mediterranean-type climate by the scarcity of natural wildfires. The Chilean matorral is highly invaded by alien plant species from other Mediterranean zones of the world, where natural, recurrent wildfires have been one of their ecological features at least since the Pliocene. This suggests that anthropogenic fires in Chile might favour alien plant recruitment, increasing the invasive process. We assessed the effect of litter burning on the emergence of alien and native species from the soil seedbank of a matorral of central Chile. Soil samples were taken from three types of microhabitats: (i) closed matorral; (ii) beneath the canopy of shrubs and trees from an open matorral; (iii) grassland. Each sample was split in two subsamples. One subsample was exposed to fire by burning the litter taken from its corresponding microhabitat, and the other subsample was left unburned and used as a control. Fire intensity, determined by the fuel type, affected more markedly the native seedbank survival than the alien one. The low-intensity fire produced by grassland litter did not significantly affect the emergence of native herbs but increased alien species richness. The high-intensity and the very high-intensity fires produced by litter burning from beneath the canopy of the closed and the open matorral, respectively, negatively affected the seedling emergence of both native and alien species, but did so in a more pronounced manner to native species. Therefore, anthropogenic fires in central Chile may promote the invasion of alien plants with favourable traits (i.e. heat-shock resistance of seeds) that are not present in the native flora.

scholarly journals Non-native species in the vascular flora of highlands and mountains of Iceland

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1559 ◽  
Author(s):  
Pawel Wasowicz
Keyword(s):  
Alien Species ◽  
Plant Species ◽  
Hot Spots ◽  
Native Species ◽  
Vascular Plant ◽  
Temporal Trends ◽  
Plant Colonization ◽  
Native Plant ◽  
Alien Plant ◽  
Vascular Plant Species

The highlands and mountains of Iceland are one of the largest remaining wilderness areas in Europe. This study aimed to provide comprehensive and up-to-date data on non-native plant species in these areas and to answer the following questions: (1) How many non-native vascular plant species inhabit highland and mountainous environments in Iceland? (2) Do temporal trends in the immigration of alien species to Iceland differ between highland and lowland areas? (3) Does the incidence of alien species in the disturbed and undisturbed areas within Icelandic highlands differ? (4) Does the spread of non-native species in Iceland proceed from lowlands to highlands? and (5) Can we detect hot-spots in the distribution of non-native taxa within the highlands? Overall, 16 non-native vascular plant species were detected, including 11 casuals and 5 naturalized taxa (1 invasive). Results showed that temporal trends in alien species immigration to highland and lowland areas are similar, but it is clear that the process of colonization of highland areas is still in its initial phase. Non-native plants tended to occur close to man-made infrastructure and buildings including huts, shelters, roads etc. Analysis of spatio-temporal patterns showed that the spread within highland areas is a second step in non-native plant colonization in Iceland. Several statically significant hot spots of alien plant occurrences were identified using the Getis-Ord Gi* statistic and these were linked to human disturbance. This research suggests that human-mediated dispersal is the main driving force increasing the risk of invasion in Iceland’s highlands and mountain areas.

Alien species Impatiens parviflora invasion into forest communities of Lithuania

2012 ◽  
Vol 18 (1) ◽  
pp. 3-12 ◽  
Author(s):  
Rasa Dobravolskaitė
Keyword(s):  
Alien Species ◽  
Plant Species ◽  
Native Species ◽  
Plant Invasions ◽  
Forest Communities ◽  
Alien Plant Species ◽  
Alien Plant ◽  
Native Communities ◽  
Impatiens Parviflora ◽  
Number Of Individuals

Abstract Dobravolskaitė R., 2012: Alien species Impatiens parviflora invasion into forest communities of Lithuania [Svetimžemės rūšies Impatiens parviflora invazija į Lietuvos miškų bendrijas]. - Bot. Lith., 18(1): 3-12. Alien plants threaten native communities by altering their species composition and reducing native biodiversity. Forests are considered to be relatively stable ecosystems and resistant to plant invasions. Impatiens parviflora DC. is one of the most intensively spreading alien plant species in the forests of Lithuania. Phenotypic variations among I. parviflora populations in three different habitat types (with different species of dominant tree and the coverage of the first tree layer) in the environs of Vilnius (South East Lithuania) were analysed. The results of the investigation enabled to evaluate alien plant species I. parviflora invasion into different forest communities and estimate relationships between plants of forest communities and I. parviflora. The study has shown that this invasive species is spreading not only in disturbed areas, but also in places where other species do not grow due to the lack of the light. However, the number of individuals is increasing in proportion while the coverage of trees and shrubs is decreasing. The rise of the level of illumination increases not only the number of individuals in the populations, but also the above-ground biomass of I. parviflora: plants are larger, produce more side shoots. The correlation between the coverage of I. parviflora and native species statistically is significantly negative (r = -0.78) in the disturbed places.

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.

scholarly journals Functional diversity changes in native and alien urban flora over three centuries

2021 ◽  
Author(s):  
Marija Milanović ◽  
Ingolf Kühn ◽  
Petr Pyšek ◽  
Sonja Knapp
Keyword(s):  
Invasive Species ◽  
Alien Species ◽  
Functional Diversity ◽  
Functional Traits ◽  
Urban Areas ◽  
Native Species ◽  
Seed Mass ◽  
Ecological Niches ◽  
Alien Plant ◽  
Over Time

AbstractAlien species in urban areas have a large effect on overall species diversity. A suitable metric of flora’s response to environmental change is functional diversity (FD) that refers to the multivariate space of species’ trait compositions, reflecting their ecological niches. We studied how FD changed over 320 years of urbanization in the city of Halle (Saale), Germany. Selected functional traits (related to stress-tolerance, reproduction, competitiveness and phenology) were examined for the difference in FD between native and alien plant species, the latter specifically for archaeophytes, neophytes and invasive species. Functional diversity for each trait was calculated using Rao’s Q index followed by a linear model to test for changes in Rao’s Q over time between the groups. Over the 320 years, overall FD remained constant despite species turnover, but FD significantly increased for neophytes and invasive species compared to native species. Plant height was the only trait showing increase in FD as main effect, while for the other traits examined FD decreased over time. Considering invasive species separately, the majority of traits exhibit a significant increase in FD except for seed mass where it decreased. Finally, FD of multiple functional traits combined decreased over time. This can be due to homogenization of functional trait between native and alien species, as a consequence of habitats becoming more similar and subsequent habitat filtering. Our results demonstrate that during the last three centuries, urbanization influenced plant FD in various ways and may contribute to future uniformity of urban floras and greater invasiveness.

scholarly journals Impacts of alien plant invasions on species richness in Mediterranean-type ecosystems: a meta-analysis

2009 ◽  
Vol 33 (3) ◽  
pp. 319-338 ◽  
Author(s):  
Mirijam Gaertner ◽  
Alana Den Breeyen ◽  
Cang Hui ◽  
David M. Richardson
Keyword(s):  
South Africa ◽  
Species Richness ◽  
Alien Species ◽  
Plant Species ◽  
Native Species ◽  
Meta Analysis ◽  
Growth Forms ◽  
Alien Plant ◽  
Native Species Richness ◽  
Mediterranean Type Ecosystems

Besides a general consensus regarding the negative impact of invasive alien species in the literature, only recently has the decline of native species attributable to biological invasions begun to be quantified in many parts of the world. The cause-effect relationship between the establishment and proliferation of alien species and the extinction of native species is, however, seldom demonstrated. We conducted a meta-analysis of studies in Mediterranean-type ecosystems (MTEs) to examine: (1) whether invasion of alien plant species indeed causes a reduction in the number of native plant species at different spatial and temporal scales; (2) which growth forms, habitat types and areas are most affected by invasions; and (3) which taxa are most responsible for native species richness declines. Our results confirm a significant decline in native species richness attributable to alien invasions. Studies conducted at small scales or sampled over long periods reveal stronger impacts of alien invasion than those at large spatial scales and over short periods. Alien species from regions with similar climates have much stronger impacts, with the native species richness in South Africa and Australia declining significantly more post-invasion than for European sites. Australian Acacia species in South Africa accounted for the most significant declines in native species richness. Among the different growth forms of alien plants, annual herbs, trees and creepers had the greatest impact, whereas graminoids generally caused insignificant changes to the native community. Native species richness of shrublands, old fields and dune vegetation showed significant declines, in contrast to insignificant declines for forest habitats.

scholarly journals Trait–environment relationships of plant species at different stages of the introduction process

NeoBiota ◽  
2020 ◽  
Vol 58 ◽  
pp. 55-74
Author(s):  
Marija Milanović ◽  
Sonja Knapp ◽  
Petr Pyšek ◽  
Ingolf Kühn
Keyword(s):  
Land Cover ◽  
Alien Species ◽  
Plant Species ◽  
Functional Traits ◽  
Environmental Conditions ◽  
Native Species ◽  
Alien Plant Species ◽  
Alien Plant ◽  
Non Invasive ◽  
The Relationship

The success of alien plant species can be attributed to differences in functional traits compared to less successful aliens as well as to native species, and thus their adaptation to environmental conditions. Studies have shown that alien (especially invasive) plant species differ from native species in traits such as specific leaf area (SLA), height, seed size or flowering period, where invasive species showed significantly higher values for these traits. Different environmental conditions, though, may promote the success of native or alien species, leading to competitive exclusion due to dissimilarity in traits between the groups. However, native and alien species can also be similar, with environmental conditions selecting for the same set of traits across species. So far, the effect of traits on invasion success has been studied without considering environmental conditions. To understand this interaction we examined the trait–environment relationship within natives, and two groups of alien plant species differing in times of introduction (archaeophytes vs. neophytes). Further, we investigated the difference between non-invasive and invasive neophytes. We analyzed the relationship between functional traits of 1,300 plant species occurring in 1000 randomly selected grid-cells across Germany and across different climatic conditions and land-cover types. Our results show that temperature, precipitation, the proportion of natural habitats, as well as the number of land-cover patches and geological patches affect archaeophytes and neophytes differently, regarding their level of urbanity (in neophytes negative for all non-urban land covers) and self-pollination (mainly positive for archaeophytes). Similar patterns were observed between non-invasive and invasive neophytes, where additionally, SLA, storage organs and the beginning of flowering were strongly related to several environmental factors. Native species did not express any strong relationship between traits and environment, possibly due to a high internal heterogeneity within this group of species. The relationship between trait and environment was more pronounced in neophytes compared to archaeophytes, and most pronounced in invasive plants. The alien species at different stages of the invasion process showed both similarities and differences in terms of the relationship between traits and the environment, showing that the success of introduced species is context-dependent.

Changes in lowland dry-forest native and alien plant communities on Réunion Island (Indian Ocean) over 16 years

Botany ◽  
2015 ◽  
Vol 93 (12) ◽  
pp. 843-857 ◽  
Author(s):  
Marion Barbé ◽  
Nicole J. Fenton ◽  
Christophe Lavergne ◽  
Timothée Le Péchon ◽  
Cláudia Baider ◽  
...  
Keyword(s):  
Alien Species ◽  
Native Species ◽  
Oceanic Islands ◽  
Dry Forest ◽  
Plant Succession ◽  
Permanent Plots ◽  
Alien Plant ◽  
Forest Remnants ◽  
Species Richness And Abundance ◽  
High Level

Native floras of oceanic islands are among the most threatened on Earth. For example, only 1% of intact dry-forest ecosystems remain on Réunion, harbouring numerous endangered native species. Alien species invasion is one of the more important threats facing these ecosystems, as it has been hypothesized that, over time, the abundance of alien species will increase more than that of native species. To explore this, we studied floristic changes over a 16 year period (1995–2011) in six dry-forest remnants. Species richness and abundance increased for both alien and native species over this period, but at a significantly higher rate for the abundance of invasive alien plants. Despite this, Jaccard’s coefficient indicates a high level of similarity between the communities of 1995 and 2011. Also, the single site that benefited from invasive species management experienced the largest increase in native species, both in terms of specific richness and abundance. This study underlines the importance of permanent plots in studying the dynamics of invaded communities and in understanding plant succession. It also suggests a potential temporal persistence of island dry-forest communities, despite the expansion of alien species, and suggests the development of a new pathway in secondary succession where native and alien species coexist.

scholarly journals Native Plant Diversity and Composition Across a Pinus radiata D.Don Plantation Landscape in South-Central Chile—The Impact of Plantation Age, Logging Roads and Alien Species

Forests ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 567 ◽  
Author(s):  
Steffi Heinrichs ◽  
Aníbal Pauchard ◽  
Peter Schall
Keyword(s):  
Alien Species ◽  
Pinus Radiata ◽  
Native Species ◽  
Natural Forest ◽  
Natural Forests ◽  
Age Classes ◽  
Central Chile ◽  
South Central ◽  
Plantation Age ◽  
Forest Remnants

Alien tree plantations are expanding globally with potential negative effects for native biodiversity. We investigated plant species diversity and composition in a Pinus radiata landscape in south-central Chile, a biodiversity hotspot, by sampling understory vegetation in different plantation age classes, along forest roads and in natural forest remnants in order to find effective conservation measures for native biodiversity. Plantations, including different age classes and roadsides, maintained high native species richness at the landscape scale but supported a completely different community composition than natural forests. Thus, natural forest remnants must be conserved as plantations cannot replace them. Certain natural forest species occurred frequently in mature plantations and can represent starting points for retaining natural elements in plantations. Generalist native and alien species benefited from plantation management, mainly in young plantations and along roadsides. Stand maturation and a closed canopy, though, reduced alien species occurrences within plantations. Along roads, shade-tolerant aliens should be monitored and removed as they can potentially invade natural forests. Native species conservation in plantations requires a holistic approach of the full mosaic of land uses including the protection of remaining natural forests, alien species monitoring along roadsides and patches with continuous canopy cover to reduce pressure by alien species.

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 Undeclared baggage: Do tourists act as vectors for seed dispersal in fynbos protected areas?

Koedoe ◽  
2015 ◽  
Vol 57 (1) ◽  
Author(s):  
Elizabeth H. Bouchard ◽  
Lawrence E. Little ◽  
Cassandra M.L. Miller ◽  
Susan M. Rundell ◽  
Elana M. Vlodaver ◽  
...  
Keyword(s):  
Seed Dispersal ◽  
Protected Areas ◽  
Alien Species ◽  
South African ◽  
National Parks ◽  
Native Species ◽  
Potential Role ◽  
Management Policy ◽  
Alien Plant ◽  
Tourism Management

Encroachment by alien species is the second greatest threat to biodiversity worldwide. As South Africa’s Cape Floristic Region has a botanical endemism of nearly 70%, conservation efforts are a high priority. Estimates suggest that alien species cost the country over R6.5 billion per year. Despite significant research on alien species dispersal, the role of tourists as seed dispersers requires further exploration. To investigate the potential role tourists play in introducing alien seeds into protected areas, long-bristle brushes were used to scrape seeds off the shoes of hikers, dog walkers and cyclists, as well as the wheels of mountain bikes and dogs themselves, upon entering the Silvermine Nature Reserve section of the Table Mountain National Park in the Western Cape province, South Africa. In addition, a vegetation survey was conducted. This comprised 18 transects at various distances from the recreational paths in the park, and used a prioritisation ranking system that identified the alien species of greatest concern. It was concluded that the greatest number of alien plant species could be found along dog paths, in comparison to the hiking trails and cycling trails. This corresponded to the findings that dog walkers had the highest incidence of seeds on their shoes, suggesting that tourists were possibly dispersing seeds from their gardens. Alien species significantly covered more of the vegetation transects closer to the trails than they did in transects further into the matrix. Because more alien species were present in areas susceptible to human disturbance, the data suggest that tourists can act as vectors for alien seed dispersal. These findings emphasise the need for active tourism management in line with the South African National Parks Biodiversity Monitoring Programme in order to prevent the introduction and spread of alien species into South Africa’s protected areas.Conservation implications: Tourism is the main source of revenue for South African National Parks, and one of the organisation’s principal goals is to create a tourism management policy conducive to conservation. This research explores the potential role that tourists may play in the introduction of non-native species into a protected area, thereby providing novel information that could assist managers in the sustainable management of protected areas.

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