scholarly journals Changes in the invasion level, and impact of alien plants in Finnish semi-natural agricultural habitats

2012 ◽  
Vol 21 (2) ◽  
pp. 100-117
Author(s):  
Miia Jauni ◽  
Juha Helenius ◽  
Terho Hyvönen
Keyword(s):  
Species Diversity ◽  
Alien Species ◽  
Native Species ◽  
Habitat Type ◽  
Geographical Location ◽  
Alien Plant ◽  
Geographical Regions ◽  
Spatio Temporal ◽  
Species Specific ◽  
The Impact

Using dataset of 508 transects of 50 m2, we assessed changes in the invasion level of alien plant species in semi-natural agricultural habitats in three study years (2001, 2005 and 2010) in four geographical regions of Finland. In addition, the impact of environmental factors on the occurrence of the most common neophytes (alien species introduced after the 17th century) and the impact of neophytes on native species diversity were studied. In total, 37 neophyte species were detected, but neophytes regarded as highly invasive were rare and occasional. We detected spatio-temporal variation in the invasion level, but it changed according to the measure used. For instance, alien species diversity was lower in south-western Finland than in other years in 2005, and the relative alien species richness was highest in southern and lowest in eastern Finland. Preferences for environmental conditions (disturbance, habitat type and geographical location) and the impact on plant diversity varied among the most common neophytes. The most common neophytes were positively rather than negatively associated with native and alien species diversity. The results suggest that alien species management and control methods should be species-specific and considered case-by-case. Neophytes do not yet cause severe problems, but regular monitoring is needed to detect changes in their invasion levels.

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 Floristics and Diversity of Invasive Alien Plant Species in Humbo District, South Ethiopia

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Markos Kuma ◽  
Zewde Achiso ◽  
Alefu Chinasho ◽  
Dalga Yaya ◽  
Samuel Tessema
Keyword(s):  
Species Diversity ◽  
Alien Species ◽  
Plant Species ◽  
Native Species ◽  
Invasive Alien Species ◽  
Fallow Land ◽  
Alien Plant Species ◽  
Grazing Land ◽  
Alien Plant ◽  
Invasive Alien Plant

Deliberate and unintentional introduction of invasive alien plant species on native biodiversity by aid agencies and other bodies directly or indirectly are being a series of problems on the economy, ecology, politics, and health of life on earth. Identifying and compiling floristics and the status of invasive alien species and identifying which have viable populations are necessary to manage the ecosystems. The present study is therefore intended to provide information for concerned bodies on the area which needs management priority computing the composition, structure, and diversity of invasive alien plants. A field assessment was conducted to determine the distribution and heterogeneity of invasive alien plant species, and then, six kebeles were chosen and transact lines were laid using a purposeful sampling technique. The vegetation and environment data were collected from farmland, grazing land, fallow land, and road sides using 95 subquadrats (5 m × 5 m) set in the center and corner of 19 main quadrats (20 m × 20 m). The voucher specimens collected were taken to the Herbarium of Ethiopia (ETH) for taxonomic identification and future reference. The frequency and density of floristics data were analyzed using MS Excel version 2010, and species diversity was calculated using Shannon (H′), Simpson (D), and evenness (E) indices. Among 35 alien plant species invading natural vegetation in Ethiopia, 25 alien plant species were found in the Humbo district of the Wolaita zone. The densest invasive alien plant species in the area were Parthenium hysterophorus consisting of 15197 individuals/ha, followed by Richardia scabra consisting of 11908 individuals/ha, Xanthium strumarium consisting of 7292 individuals/ha, and Ocimum forskolei consisting of 6280 individuals/ha. The highest species diversity was computed in fallow land (H′ = 2.369), which is followed by farmland (H′ = 1.627) and grazing land (H′ = 1.419). The higher the density of the invasive alien species, the higher the ability to change the structure and diversity of native species of the area results in a decrease in the function and services of the ecosystem. Therefore, management methods must prioritize land types that had the highest diversity of invasive alien species.

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 High Recovery of Saplings after Severe Drought in Temperate Deciduous Forests

Forests ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 546 ◽  
Author(s):  
Mirela Beloiu ◽  
Reinhold Stahlmann ◽  
Carl Beierkuhnlein
Keyword(s):  
Drought Stress ◽  
Species Diversity ◽  
Tree Species ◽  
Management Strategies ◽  
Field Measurements ◽  
Species Interaction ◽  
Severe Drought ◽  
Crown Defoliation ◽  
Species Specific ◽  
The Impact

Drought episodes are predicted to increase their intensity and frequency globally, which will have a particular impact on forest vitality, productivity, and species distribution. However, the impact of tree species interaction on forest vulnerability to drought is not yet clear. This study aims to assess how deciduous saplings react to drought and whether tree species diversity can buffer the impact of drought stress on tree saplings. Based on field measurements of crown defoliation and species diversity, vulnerability, drought recovery, and species interaction were analyzed. Fieldwork was carried out in Central Eastern Germany in 2018 during the vegetation season and repeated in 2019. Ten random saplings were measured in each of the 218 plots (15 × 15 m) with 2051 saplings in total out of 41 tree species. We found that 65% of the saplings experienced defoliation during the drought of 2018, of which up to 13% showed complete defoliation. At the species level, Fagus sylvatica L. and Betula pendula Roth. saplings were less affected (<55%), whereas Carpinus betulus L., Sorbus aucuparia L., and Frangula alnus Mill. saplings were the most affected (≥85%). One year later, in 2019, C. betulus and S. aucuparia had a faster recovery rate than F. sylvatica, B. pendula, Quercus spp., and Crataegus spp. (p < 0.001). Furthermore, we showed that forest stands with high sapling species diversity had a reduced vitality under drought stress (p < 0.001), indicating a higher competition for resources. The study provides evidence that F. sylvatica saplings can withstand and survive to persistent drought. Species-specific responses to drought are essential to be considered for implementing adaptive forest management strategies to mitigate the impact of climate change.

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.

Distribution pattern of the invasive alien plant Bunias orientalis in Rów Podtatrzański trench, north of the Tatra Mts, Poland

Biologia ◽  
2014 ◽  
Vol 69 (3) ◽  
Author(s):  
Piotr Kiełtyk
Keyword(s):  
Species Diversity ◽  
Alien Species ◽  
Diversity Index ◽  
Vegetation Composition ◽  
Alien Plant ◽  
Anthropogenic Habitats ◽  
Invasive Alien Plant ◽  
Significant Relationships ◽  
Bunias Orientalis ◽  
Tatra Mts

AbstractBunias orientalis is an alien species that has spread greatly in recent decades in Central Europe. This coloniser is particularly well (pre)adapted to anthropogenic disturbances and human-mediated dispersal, allowing it to spread mainly along roads and railways. Here, its distribution and population structure is investigated for the sub-montane region located in the northern foothills of the Tatra Mts. Based on 70 phytosociological samples of invading vegetation, the relationships between B. orientalis cover and species diversity, together with the composition of vegetation, were analysed using regression analysis. Comparison of the current distribution of B. orientalis within the investigated area with published records indicates that the expansion rate of this alien species is not particularly high, despite its increased frequency in anthropogenic habitats and meadows. Meadows invaded by this species revealed that increased B. orientalis cover was accompanied by a significant reduction in the values of the Inverse Simpson diversity index and Pielou’s measure of evenness. Reduced diversity was caused by considerable decrease in cover by species of the Molinio-Arrhenatheretea class. However, for anthropogenic habitats, no statistically significant relationships were found to occur between the abundance of B. orientalis, species diversity and vegetation composition.

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.

scholarly journals Invasion of alien plant species and their impact on different ecosystems of Panchase Area, Nepal

2017 ◽  
Vol 27 (1) ◽  
pp. 31-42 ◽  
Author(s):  
S. Baral ◽  
A Adhikari ◽  
R. Khanal ◽  
Y. Malla ◽  
R. Kunwar ◽  
...  
Keyword(s):  
Plant Species ◽  
Native Species ◽  
Household Survey ◽  
Gis Mapping ◽  
Negative Consequences ◽  
Agricultural Lands ◽  
Alien Plant Species ◽  
Alien Plant ◽  
Invasive Alien Plant ◽  
The Impact

The aggressiveness of invasive alien plant species has been amidst the changing climate, which has necessitated further research in this area. The impact of invasive alien plant species in the Panchase area of Nepal was assessed through the forest resource assessment and other methodologies such as, household survey, group discussion, direct field observation, participatory cluster mapping, quadrat sampling, laboratory analysis, and GIS mapping. A total of nine major invasive species, in which Ageratum houstonianum and Ageratina adenophora were found spread throughout the ecosystem. The invasion was fueled by anthropogenic disturbances such as leaving the agricultural lands, fallow and degradation of habitat. As a consequence, native species such as Artemisia indica and Urtica dioica were outcompeted mostly in the fringes of fallow lands, agricultural lands and in the disturbed sites. The intrusion was, however, less in the forest area, implying that community-managed dense canopy forests are less susceptible to invasion and routine management can offset the negative effects of invasion. Even though many negative consequences of the invasion were observed in the study sites, the possibility of the economically exploiting the biomass of invasive alien plant species for generating income locally was noticed.Banko Janakari, Vol. 27, No. 1, page: 31-42

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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