Passive Reestablishment of Riparian Vegetation Following Removal of Invasive Knotweed (Polygonum)

2013 ◽  
Vol 6 (2) ◽  
pp. 208-218 ◽  
Author(s):  
Shannon M. Claeson ◽  
Peter A. Bisson
Keyword(s):  
Species Diversity ◽  
Plant Species ◽  
Native Species ◽  
Vascular Plant ◽  
Tree Cover ◽  
Native Plant ◽  
Japanese Knotweed ◽  
Vegetative Cover ◽  
Reference Sites ◽  
Habitat Features

AbstractJapanese knotweed and congeners are invasive to North America and Europe and spread aggressively along rivers establishing dense monotypic stands, thereby reducing native riparian plant diversity, structure, and function. Noxious weed control programs attempt to eradicate the knotweed with repeated herbicide applications under the assumption that the system will recover to a native assemblage which will inhibit future invasions. However, eradication efficacy studies typically only measure the amount of knotweed reduced, not the reestablished species diversity or plant origins. For a community scale efficacy study, we measured vascular plant species diversity and cover in riparian areas along five rivers in Washington State, 3 to 6 years after Bohemian knotweed was initially treated with herbicide. Plant species composition was compared between riparian sites treated to remove knotweed and reference sites where knotweed was absent. Sites where knotweed had been removed had significantly more exotic species and vegetative cover than reference sites; however, native species richness and cover were greater in reference sites and areas with more overstory vegetation. The native plants observed were primarily shade tolerant and perennial, as opposed to many of the exotics, which were shade-intolerant annuals. In general, reestablishment of native and exotic vegetation was not related to pretreatment knotweed stem count, size of the invaded area, or timing of herbicide application. However, residual native tree cover was negatively correlated with initial knotweed stem count. Monitoring the success of restoration objectives (e.g., native plant reestablishment or increased species diversity) and characterizing associated habitat features following knotweed eradication will help in the development of site-specific protocols for successful plant community scale restoration.

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

2015 ◽  
Author(s):  
Pawel Wasowicz
Keyword(s):  
Plant Species ◽  
Native Species ◽  
Hot Springs ◽  
Vascular Plant ◽  
Temporal Trends ◽  
Plant Colonization ◽  
Native Plant ◽  
Alien Plant ◽  
Alien Flora ◽  
Central Highland

Highlands and mountains of Iceland (defined here as areas located above 400 m a.s.l) are considered to be the largest remaining wilderness areas in Europe. The present study provides first comprehensive and up-to-date data on non-native plant species from this area. The study was aimed to provide a checklist of alien plant species recorded from highland and mountain areas of Iceland, assess their naturalisation status, define spatial patterns and hotspots of their distribution and analyse temporal trends in the data. The presence of 18 non-native vascular plant species was evidenced including 13 casuals and 5 naturalised taxa (1 invasive). The results showed that the central highland is most vulnerable to alien plant colonisation, while mountain and highland areas in other parts of the country are much less impacted by non-native plant taxa. Clear hotspots of occurrence of alien flora can be defined and their geographic location corresponds to places of touristic interest such as hot springs, geothermal areas, mountain huts and shelters as well as main roads and tracks. Temporal trends characterizing non-native plant colonization show clearly that the process is still in its initial phase. The research suggests that human-mediated dispersal is the major force contributing to increased invasion risk within the investigated area.

scholarly journals Plant species diversity in urban areas of Northwest Siberia

2021 ◽  
Vol 66 (2) ◽  
Author(s):  
Elena Koptseva ◽  
Olga Sumina ◽  
Pavel Kirillov ◽  
Alexandr Egorov ◽  
Alexandr Pechkin
Keyword(s):  
Species Diversity ◽  
Plant Species ◽  
Urban Areas ◽  
Native Species ◽  
Vascular Plant ◽  
Northern Taiga ◽  
City Development ◽  
Native Flora ◽  
Functional Zones ◽  
Weed Distribution

The flora of two towns and two settlements in the northern taiga and forest-tundra of Northwest Siberia (Russia) are considered. Urban species lists are limited (61–119 vascular plant species) and mainly consist of native species with a predominance of perennial herbs. Various urban functional zones (industrial, residential, recreational, vegetable patches) differ by species composition, and this difference increases in the course of city development. In the industrial zone, vegetation composition is closer to the native flora, because of the low number of adventive species. Maximal diversity is due to decorative plants, cultivars and southern weed distribution, and is typical to residential neighborhoods. Species diversity increases mainly because of woody plants introduction. Alien species are represented generally by a small number of individuals. The severe climate and poor soils limit their abilities to spread in the Far North. Urbanization forces the reduction of aboriginal biodiversity, but in northern areas where native species have the adaptive advantage, this effect is minimal. Changes in flora since 1995 were analyzed in the town of Novy Urengoy (Yamalo-Nenets Autonomous Okrug, Russia). Plant diversity increased by about 20 % in all functional zones, although some alien and natural species were not recorded in 2018.

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.

SGS Biodiversity Theme: impact of plant biodiversity on the productivity and stability of grazing systems across southern Australia

2003 ◽  
Vol 43 (8) ◽  
pp. 961 ◽  
Author(s):  
D. R. Kemp ◽  
W. McG. King ◽  
A. R. Gilmour ◽  
G. M. Lodge ◽  
S. R. Murphy ◽  
...  
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Plant Species ◽  
Native Species ◽  
Management Practices ◽  
Plant Species Diversity ◽  
Native Plant ◽  
Total Species Richness ◽  
Grazing Systems ◽  
Sustainable Grazing

The relationships between productivity and plant species diversity were assessed using data from the Sustainable Grazing Systems (SGS) 10 national experiment sites. Each site applied up to 7 different management treatments. Sites varied in the amount of data available for analysis. Plant species diversity was assessed in terms of both the total and native species present at each site. More than 200 plant taxa were recorded over the period of the experiment, about one-third of which were native. In the majority of cases, the native species present within a treatment remained there throughout the experiments, even when fertilised and oversown with introduced species. The number of native species increased by 1 or 2 over the 3–4 years of each experiment where grasslands were less intensively used (average herbage mass >2 t DM/ha), but decreased in more heavily grazed treatments. Native grasses made much greater contributions to herbage mass than other native species. Of the more than 70 native plant species found, the most numerous were broadleaf species, which tended to be more variable under management treatments. As total species richness increased, there was a tendency for pasture productivity to be less, for the mean standing herbage mass to be less and for seasonal growth to be less stable. This depended upon experiments and tended to apply at the sites with higher annual pasture growth rates. All treatments had >10 plant species within the small (about 1.5 ha) paddocks used and larger paddocks often had many more. It was apparent from the high plant species richness at each site (about 25–100 species) that many more niches exist in these paddocks than the number of species usually sown in a pasture. Opportunities to redesign pasture mixtures to exploit more of the resources available obviously exist. Understanding of the relationships among management practices, productivity and plant species diversity is limited, but will become important as we seek more sustainable grazing systems. The studies analysed here suggested that where the herbage mass was maintained between 2 and 4 t DM/ha then species were maintained and productivity was optimised.

scholarly journals The invasive Opuntia ficus-indica homogenizes native plant species compositions in the highlands of Eritrea

2020 ◽  
Author(s):  
Yohannes B. Tesfay ◽  
Juergen Kreyling
Keyword(s):  
Species Diversity ◽  
Species Composition ◽  
Plant Species ◽  
Native Species ◽  
Diversity Index ◽  
Native Plant ◽  
Opuntia Ficus Indica ◽  
Native Plant Species ◽  
Negative Effect ◽  
Dry Climates

Abstract Invasion by exotic species is recognized as one of the major threats to biodiversity. The effects of invasion by Opuntia ficus-indica (Cactaceae) on the species diversity, richness and composition of invaded communities were studied at three sites in the highlands of Eritrea, East Africa. This paper investigates whether the presence of O. ficus-indica causes a negative effect on the native biodiversity in a region rarely studied so far. The vegetation in invaded and uninvaded plots with similar habitat conditions was sampled and differences in the species composition, diversity and richness were compared between the plots. The overall plant species composition differed significantly with invasion by O. ficus-indica. The invasion by O. ficus-indica also led to a significant homogenization of community compositions. The species richness and Shannon diversity index did not differ significantly between the invaded and uninvaded plots. Nevertheless, we still detected species with significantly lower occurrence in the invaded plots (Psiadia punctulata), but also species which preferred invaded plots (Plectranthus hadiensis). We conclude that O. ficus-indica exerts a negligible effect on the species diversity and richness but that it affects species composition and that there are species which suffer due to its presence. Due to the continuous pressure of the invasion by O. ficus-indica on the species composition and dry climates, further homogenization in the native species diversity is to be expected in the future for the highlands of Eritrea.

scholarly journals Hosts of Raoiella indica Hirst (Acari: Tenuipalpidae) Native to the Brazilian Amazon

2017 ◽  
Vol 9 (4) ◽  
pp. 86 ◽  
Author(s):  
Cristina A. Gómez-Moya ◽  
Talita P. S. Lima ◽  
Elisângela G. F. Morais ◽  
Manoel G. C. Gondim Jr. ◽  
Gilberto J. De Moraes
Keyword(s):  
Plant Species ◽  
Native Species ◽  
Brazilian Amazon ◽  
Intrinsic Rate Of Increase ◽  
Native Plant ◽  
Instantaneous Rate ◽  
Net Reproductive Rate ◽  
Musa Paradisiaca ◽  
Rate Of Increase ◽  
Raoiella Indica

The expansion of red palm mite (RPM), Raoiella indica (Acari: Tenuipalpidae) in Brazil could impact negatively the native plant species, especially of the family Arecaceae. To determine which species could be at risk, we investigated the development and reproductive potential of R. indica on 19 plant species including 13 native species to the Brazilian Amazon (12 Arecaceae and one Heliconiaceae), and six exotic species, four Arecaceae, a Musaceae and a Zingiberaceae. Values of the instantaneous rate of increase (ri) were initially estimated at 7, 14, 21 and 28 days after infestation of each species. Higher values of ri (> 0.05) were determined on the Arecaceae Adonidia merrillii, Astrocaryum jauari, Cocos nucifera, Bactris simplicifrons, Mauritia flexuosa, Phoenix dactylifera and Socratea exorrhiza, and on the Heliconiaceae Heliconia psittacorum Sassy; these were classified as “potential primary hosts”. Lower, but still positive values of ri (0-0.05) were determined on the Arecaceae Bactris maraja, Oenocarpus bacaba, Oenocarpus bataua and on the Musaceae Musa × paradisiaca (Prata variety); these were classified as “potential secondary hosts”. Negative values of ri were determined for the remaining plants, i.e., the Arecaceae Astrocaryum aculeatum, Attalea maripa, Bactris gasipaes, Elaeis guineensis, Euterpe oleracea, Euterpe precatoria, and the Zingiberaceae Alpinia rosea; these were considered “non-hosts”. Species with ri < 0.05 were considered not to be threatened by the RPM. Biological parameters of RPM were evaluated on the plant species with positive ri (except B. maraja) and two native species with negative ri (E. oleracea and E. precatoria). Mean developmental time ranged from 14.7 days on C. nucifera to 21.4 days on Musa × paradisiaca, showing a significant influence of the plant substrate. Immature viability, oviposition rate, net reproductive rate (R0) and intrinsic rate of increase (rm) were affected by the plant species.

scholarly journals Emerging fungal pathogen of an invasive grass: Implications for competition with native plant species

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0237894
Author(s):  
Amy E. Kendig ◽  
Vida J. Svahnström ◽  
Ashish Adhikari ◽  
Philip F. Harmon ◽  
S. Luke Flory
Keyword(s):  
Invasive Species ◽  
Plant Species ◽  
Fungal Pathogen ◽  
Native Species ◽  
Grass Species ◽  
Leaf Spot Disease ◽  
Native Plant ◽  
Invasive Grass ◽  
Native Plant Species ◽  
Species Specific

Infectious diseases and invasive species can be strong drivers of biological systems that may interact to shift plant community composition. For example, disease can modify resource competition between invasive and native species. Invasive species tend to interact with a diversity of native species, and it is unclear how native species differ in response to disease-mediated competition with invasive species. Here, we quantified the biomass responses of three native North American grass species (Dichanthelium clandestinum, Elymus virginicus, and Eragrostis spectabilis) to disease-mediated competition with the non-native invasive grass Microstegium vimineum. The foliar fungal pathogen Bipolaris gigantea has recently emerged in Microstegium populations, causing a leaf spot disease that reduces Microstegium biomass and seed production. In a greenhouse experiment, we examined the effects of B. gigantea inoculation on two components of competitive ability for each native species: growth in the absence of competition and biomass responses to increasing densities of Microstegium. Bipolaris gigantea inoculation affected each of the three native species in unique ways, by increasing (Dichanthelium), decreasing (Elymus), or not changing (Eragrostis) their growth in the absence of competition relative to mock inoculation. Bipolaris gigantea inoculation did not, however, affect Microstegium biomass or mediate the effect of Microstegium density on native plant biomass. Thus, B. gigantea had species-specific effects on native plant competition with Microstegium through species-specific biomass responses to B. gigantea inoculation, but not through modified responses to Microstegium density. Our results suggest that disease may uniquely modify competitive interactions between invasive and native plants for different native plant species.

Enumeration of Plant Species Inhabiting Oil Palm Trees (Elaeis-guineensis) at Zawlpui Plantation Site, Serchhip District, Mizoram

2021 ◽  
Vol 9 (1) ◽  
pp. 32-35
Author(s):  
Lal awmpuia ◽  
◽  
H. Lalruatsanga ◽  
Keyword(s):  
Species Diversity ◽  
Plant Species ◽  
Oil Palm ◽  
Elaeis Guineensis ◽  
Vascular Plant ◽  
Fungal Species ◽  
Small Scale ◽  
Palm Tree ◽  
Palm Trees ◽  
Plant Stem

A survey of plant species inhabiting oil palm trees was conducted in Zawlpui area of Serchhip district, Mizoram. The study area is a tropical potent agriculture zone, wherein small-scale business of Elaeis guineensis plantation is carried out by several farmers mainly within the gentle sloppy terrain. Oil palm with a rough bark harbors immense inhabitation by a variety plants, that rooted mostly on the debris at leaf base. Species diversity on the plant stem supposedly encourage insects and termites to establish herewith, thus causing harming to the tree. The sample stands within 400 m–800 m altitude were picked randomly. A total of 50 palm tree were accounted and all associated plants on the stem above 30 cm from the ground are all recorded. Species that cannot be identified on the site were pressed and observed at Botany Research lab, Pachhunga University College. The survey documented 38 vascular plant species which include 4 epiphytes and 1 non-vascular species of lichen, 1 bryophyte and 4 fungal species at that time. Invasive Peperomia pellucida and epiphytic pteridophytes Nephrolepis biserrata was found in most of the stand sample; however, Peperomia population decreases with the increasing elevation. Dynamics of inhabitant species diversity also correlate to location of tree. The study also established that diversity of inhabiting species was comparatively high on parts of the stem facing sunlight.

Urban conservation gardening in the decade of restoration

2021 ◽  
Author(s):  
Ingmar Staude ◽  
Josiane Segar ◽  
Corey Thomas Callaghan ◽  
Emma Ladouceur ◽  
Jasper Meya ◽  
...  
Keyword(s):  
Plant Species ◽  
Native Species ◽  
Species Conservation ◽  
Plant Conservation ◽  
Native Plant ◽  
Nature Protection ◽  
Urban Conservation ◽  
Native Plant Species ◽  
Native Seed ◽  
Conservation Gardening

Global commitments to species conservation have failed to halt systematic widespread declines in plant species. Current policy interventions, such as protected areas and legal species legislation, remain insufficient, and there is an urgent need to engage novel approaches and actors in conservation. Here, we propose that urban conservation gardening, namely the cultivation of declining native plant species in public and private green spaces, can be one such approach. Conservation gardening can address key (a)biotic drivers of species decline, act as a critical dispersal pathway and increase the occupancy of declining native species. We identify policy mechanisms to upscale conservation gardening to a mainstream activity by reforming the existing horticultural market into an innovative nature protection instrument. This involves incentivizing the integration of the native seed sector, leveraging existing certification and labelling schemes, promoting consumer access, as well as building citizen-science projects to foster public engagement. Mainstreamed conservation gardening can be an economically viable, sustainable, and participatory measure that complements traditional approaches to plant conservation.

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