scholarly journals Urban Rivers as Dispersal Corridors: Which Factors Are Important for the Spread of Alien Woody Species along the Danube?

2020 ◽  
Vol 12 (6) ◽  
pp. 2185
Author(s):  
Sabrina Wagner ◽  
Dietmar Moser ◽  
Franz Essl

Cities are hotspots of invasions, and this is particularly the case for urban rivers, which are known to serve as corridors for the spread of alien plant species to floodplain forests. Here, we present a case study on woody (shrubs, trees) species invasions across a gradient from a metropolis (Vienna) to rural regions along the Danube River in eastern Austria. In total, we identified 44 native and 25 alien woody species in 75 plots. Five alien woody species occur in at least 10 plots. The most wide-spread ones were species of floodplain forests (Acer negundo, Fraxinus pennsylvanica, and Populus x canadensis), while Ailanthus altissima and Robinia pseudoacacia—which prefer dry sites—were recorded substantially less often. The average level of invasion—i.e., the relative proportion of alien to native woody species in plots—was high across all three study regions. Still, there was a moderate decline of alien woody species richness along the urban—peri-urban—rural gradient. Generalized Linear Mixed Models showed that population density and the proportion of urban habitats in the environs of the plots is significantly positively correlated with the presence of Acer negundo and Ailanthus altissima. Conversely, the occurrence of Robinia pseudoacacia is negatively correlated with surrounding population density and urban habitats. Occurrence of Acer negundo is positively correlated with urban habitats. For Fraxinus pennsylvanica, we found no significant relationships. Our results confirm that gallery forests at river banks are highly susceptible to invasions. We argue that managing alien woody species in urban and peri-urban sites is not appropriate and useful, given that re-invasion is likely in most cases (from adjacent urban green spaces). We acknowledge that this recommendation entails the implicit recognition that gallery forests along urban sections of the Danube will contain a substantial—and likely further increasing—proportion of alien woody species.

2019 ◽  
Vol 27 (3) ◽  
pp. 276-290 ◽  
Author(s):  
R. I. Burda ◽  
S. N. Koniakin

The process of invasion, naturalization, dispersion and invasive activity of non-native woody species in 5 regional floras, 5 urban floras and over 30 floras of the protected areas is discussed. It has been established that 182 non-native species out of 95 genera and 45 families are currently at different naturalization stages in the spontaneous flora of Ukraine. In terms of life-forms, they may be divided as follows: trees – 41%, shrubs – 35%, trees/shrubs – 15%, lianas – 9%. Most species spread both via seed dispersal and the vegetative way – 56%, using only seed dispersal – 42%, only the vegetative way – 2%. According to the preliminary rating of species-wise invasive activity, 71 species (40%) have naturalized completely, among them 20 invasive species, including 12 transformer species, 29 potentially invasive species, and 22 naturalized species which demonstrate no invasive tendencies. The initial stages of invasion of 111 species are as follows: introduction – 9%, survival – 36%, adaptation of the reproductive sphere – 28%, establishment, formative of local populations – 27%. In terms of dispersion, non-naturalized species are divided as follows: rare – 45%, local – 16%, sporadic – 6%, unique – 12%, spreading under control beyond collections and expositions in botanical gardens and arboretums – 21%. Twelve transformer species, the greatest threat to local diversity, are Acer negundo, Ailanthus altissima, Amorpha fruticosa, Bupleurum fruticosum, Elaeagnus angustifolia, E. rhamnoides, Fraxinus ornus, Parthenocissus quinquefolia, P. vitacea, Robinia pseudoacacia, Rhamnus alaternus, Salix × blanda and 8 invasive proper species: Berberis aquifolia, Colutea orientalis, Daphne laureola, Prunus cerasifera, P. serotina, Quercus ilex, Viburnum tinus, Vitis vinifera. The list of alien species, most widespread in 50 regions of Europe, includes Robinia pseudoacacia (42 regions), Ailanthus altissima (40), Acer negundo (38), Prunus cerasus (34), Quercus rubra (34), Rosa rugosa (34), Prunus domestica (31). The mitigation of the impacts of these species on local biodiversity is possible via the restoration of local native plant communities, land use organization, strict selection of introduced species prior to the introduction, culture of planting management, preventive measures and extending awareness and sharing of information about plant invasions. Therefore, Ukraine’s spontaneous flora is notable for the active process of naturalization of non-native woody species with considerable involvement of invasive alien species. This is the first and preliminary evaluation of the invasive activity of woody species in Ukraine’s flora. The manifestations of the global tendency of increased involvement and invasive activity of alien woody species in domestic flora have been confirmed. These conclusions are also relevant for elaborating the system of preventive, containing and mitigating measures regarding plant invasions in Ukraine.


1976 ◽  
Vol 54 (21) ◽  
pp. 2473-2477 ◽  
Author(s):  
P. E. Marshall ◽  
T. T. Kozlowski

The nature and rate of breakdown of food reserves in cotyledons varied markedly among species. Embryonic cotyledons of Acer negundo L. stored mostly proteins, whereas those of Ailanthus altissima (Mill.) Swingle were fat-storing. Fraxinus pennsylvanica Marsh, cotyledons contained nearly equal quantities of lipids and proteins (45% of dry weight for each) as did those of Robinia pseudoacacia L. (25% dry weight for each). Total nonstructural carbohydrate contents of embryonic cotyledons of Acer and Robinia (exalbuminous species) were considerably higher than those of Ailanthus or Fraxinus (albuminous species). Carbohydrate contents of Acer and Robinia cotyledons initially decreased, but carbohydrate contents of all four species increased rapidly as cotyledons became chlorophyllous and photosynthetic. Synthesis of cotyledonary chlorophyll and emergence of cotyledons occurred faster for seedlings of Acer and Robinia than for those of Ailanthus and Fraxinus. Protein and lipid contents of cotyledons of all four species declined as cotyledons matured after germination.


1977 ◽  
Vol 55 (2) ◽  
pp. 208-215 ◽  
Author(s):  
P. E. Marshall ◽  
T. T. Kozlowski

Variations in anatomy and stomatal characteristics of cotyledons were studied with light microscopy and scanning electron microscopy during postgermination development. Species investigated were Acer negundo L., Ailanthus altissima (Mill.) Swingle, Fraxinus pennsylvanica Marsh., and Robinia pseudoacacia L. During their development, cotyledons of all species progressed through storage, transition, photosynthetic, and senescent stages. When germination was initiated, most cells of embryonic cotyledons were filled with reserve materials (lipids, proteins, and carbohydrates). Embryonic cotyledons lacked functional stomata, and those of very few species had developing guard-cell mother cells. In embryonic cotyledons, the mesophyll was differentiated into palisade and spongy parenchyma. Amounts of cotyledon expansion varied greatly among species, and cotyledon expansion was due primarily to increased cell size. Emergence of cotyledons from seed coats occurred over a range of seedling ages, depending on species. After cotyledons emerged, chlorophyll was rapidly synthesized and stomata became functional. Anatomical characteristics of cotyledons were much different from those of foliage leaves. Leaves were much thinner and had smaller parenchyma cells than did cotyledons. Cotyledons of Acer negundo and Robinia pseudoacacia were relatively short-lived (less than 30days), while those of the other species were more persistent.


Hacquetia ◽  
2019 ◽  
Vol 18 (2) ◽  
pp. 233-270 ◽  
Author(s):  
Anatoliy Khapugin

Abstract Paper presents a systematic global review of Acer negundo, Fraxinus pennsylvanica, Ailanthus altissima, Robinia pseudoacacia invasions focusing on the Scopus and Web of Science databases. We examined the data on papers, study areas, habitat studied, topic discussed. We hypothesized that these species were studied evenly throughout their invaded ranges and, as such, indexed by international databases. We asked whether four selected species are presented evenly in publications related to their invaded ranges, and whether both selected databases cover well a content of these papers. We found 48 papers for A. negundo, 14 – for F. pennsylvanica, 83 – for A. altissima, 96 – for R. pseudoacacia. A high percentage of the studies were conducted in Central Europe and USA (for A. altissima), while Eastern Europe, Russia, Western United States were poorly represented. Most studies were conducted in forests, and focused on impacts or distribution of aliens in invaded range, and their control and management. We encountered habitat types invaded by trees, factors influencing tree invasions, consequences of invaders’ impact on ecosystems, counteracting measures. We concluded that the use only Web of Science and Scopus is not sufficient to obtain the complete data about the invasion biology.


2012 ◽  
Vol 64 (3) ◽  
pp. 1217-1225 ◽  
Author(s):  
Dobrila Lukic ◽  
D. Karadzic ◽  
M. Radovanovic ◽  
M. Milenkovic ◽  
Mirjana Gajic ◽  
...  

The most represented tree species in the Banjica Forest are Acer negundo, Quercus robur, Acer pseudoplatanus, Populus nigra, Fraxinus pennsylvanica, Fraxinus ornus and Robinia pseudoacacia. According to the ICP Forests combined assessment (degree of defoliation and decolorization), endangered species are Populus nigra (64.3% of heavily damaged trees), Quercus robur (45.5%), Fraxinus pennsylvanica (37.0%) and Acer negundo (26.6%), while the situation is much better for Acer pseudoplatanus and Fraxinus ornus. For Robinia pseudoacacia, 83% of trees are without decolorization, however, defoliation is established. In the period from April to October 2009, the average pH of rainwater was 5.46, and 5.18 in the period from November 2009 to March 2010. The concentration of SO42- in the period from April to October 2009 amounted to an average of 24.21 mg/l, and 28.87 mg/l in the period from November 2009 to March 2010. The concentration of SO42- and pH values is a possible explanation for the condition of the trees.


Les/Wood ◽  
2021 ◽  
Vol 70 (1) ◽  
Author(s):  
Dominika Gornik Bučar ◽  
Peter Prislan ◽  
Pavel Smolnikar ◽  
Darja Stare ◽  
Nike Krajnc ◽  
...  

Na laboratorijski peletirni napravi smo izdelali pelete iz petih izbranih tujerodnih invazivnih drevesnih vrst, ki rastejo na območju Slovenije in sicer: divjega kostanja (Aesculus hippocastanum), amerikanskega javora (Acer negundo), robinije (Robinia pseudoacacia), trnate gledičevke (Gleditsia triacanthos) in velikega pajesena (Ailanthus altissima) ter mešanic surovine omenjenih tujerodnih invazivnih vrst s smrekovino (Picea abies) v razmerjih 70 : 30 in 50 : 50. Pod enakimi proizvodnimi pogoji smo skupno izdelali 15 različnih vrst peletov. Izdelanim peletom smo določili pomembnejše fizikalne in mehanske lastnosti (vsebnost vode, gostoto nasutja, mehansko obstojnost in vsebnost pepela). Rezultate smo primerjali z mejnimi vrednostmi, opredeljenimi v standardu SIST EN ISO 17225-2:2014. Vsebnost vode in gostota nasutja vseh izdelanih vrst peletov sta zadostili zahtevam standarda za razvrstitev v najvišji kakovostni razred A1. Mehanske obstojnosti izdelanih peletov niso dosegale zahtev standarda in niso presegale 96,5 % (kar je mejna vrednost za B razred). Rezultati kažejo, da imajo med izbranimi tujerodnimi invazivnimi drevesnimi vrstami največji potencial za nadaljnjo optimizacijo peletirnega postopka robinija, trnata gledičevka in visoki pajesen.


Author(s):  
I. I. Korshіkov ◽  
Y. M. Petrushkevych ◽  
S. I. Shkuta

The article is devoted to the study of woody plants communities, that spontaneously form in the abandoned areas of Kryvyi Rih Area as a result of spontaneous-invasive settling of species in previously established plantations. For the study, we laid 16 trial plots in 5 growth sites of such communities. We determined the species composition and biometric characteristics of primary woody plants and those, that formed these communities due to the invasion. In the first such community, which was formed due to the settling of other species in a 40-year-old plantation of Salix alba L., we found on 3 plots with an area of 625 m2 94 medium-sized trees Acer negundo L. having height (h) 11.8–13.6 m, trunk diameter (D) 16.8–17.3 cm and crown projection area (S) 9.5–10.4 m2, as well as 210 young generative trees, their height varies between 6.5–7.3 m, trunk diameter 5.0–5.4 cm, and the projection of the crown 2.5–6.3 m2. In this community also grow young and medium-generative trees of Robinia pseudoacacia L. – respectively 7 individuals – h = 7.2–11.7 m, D = 8.1–10.7 cm, S = 6.1–6.5 m2 and 7 ones – h = 13.5–14.0 m, D = 18.1–27.0 cm, S = 14.0–38.5 m2. Among self-seeding plants, such species predominate: Acer platanoides L. – 3905 specimens and Acer negundo – 1823 specimens. Three species dominate in the three dense forestation massive near the highway, which occupy an area of 250 m2: Robinia pseudoacacia, Ulmus pumila L., Fraxinus excelsior L. and Cerasus avium (L.) Moench. Robinia pseudoacacia is the most common among medium-generative plants, and Acer negundo, A. platanoides, A. tataricum L. – among young generative plants. Self-seeding of Robinia pseudoacacia, Acer platanoides, Fraxinus excelsior and Acer negundo is dominated in this area. In the abandoned Ulmus pumila plantation near the iron ore mine in three areas with an area of 625 m2, 12 to 33 specimens of medium-generative trees of this species with a height of 12.2–13.1 m with a trunk diameter of 14.7–16.0 cm and a crown projection of 25, 5–27.3 m2. Its self-seeding is quite active in all areas. Self-seeding plants of Acer negundo are also present here – 51 specimens and Acer platanoides – 35 ones. Self-seeding plants of A. platanoides – 9837 specimens, A. pseudoplatanus – 2111 specimens, Ailanthus altissima (Mill.) Swingle – 396 specimens dominate in the neglected park on the territory of 500 m2, where Acer pseudoplatanus, Acer platanoides, Robinia pseudoacacia grow. A study was also carried out on the example of the Zelena gully in order to determine how invasive species spontaneously penetrate into the formed steppe feathergrass-fescue phytocenoses. In the upper part of the Zelena gully, located outside of Kryvyi Rih, more than 40 years ago, forest belts were created from many species of shrubs, which have already been listed. Crataegus fallacina Klokov and Rhamnus cathartica L. diffusely inhabit and clearly predominate in the 6 trial plots that were laid on the slopes of the south-eastern and north-western exposures. In the presence of a large number of seed donors from the previously mentioned species on the slopes of the gully firstly Crataegus fallacina settles. Morphometric parameters of shrubs of these species were slightly larger on the north-western slope than on the south-eastern: the height of Crataegus fallacina – 2.5–2.9 m, and the diameter of the crown – 3.5–4.3 m, while in Rhamnus cathartica – the height of the bush was 0.7–0.8 m, and the diameter of the crown – 0.5–1.1 m. Thus, invasive species of Ulmus pumila, Acer negundo, Robinia pseudoacacia and Ailanthus altissima, which are the main in spontaneous communities in abandoned anthropogenically disturbed areas of the city, do not penetrate into stable phytocenoses. Most of these species of woody plants show low invasive activity and do not form multispecies communities in weakly disturbed feather-fescue phytocenoses.


2020 ◽  
Vol 47 (2) ◽  
pp. 109-120
Author(s):  
Ján Supuka ◽  
Attila Tóth ◽  
Mária Bihuňová ◽  
Martina Verešová ◽  
Karol Šinka

AbstractThe woody plant species composition has been evaluated in three cadastral territories of southwestern Slovakia, together in 77 habitats of non-forest woody vegetation (NFWV). A total of 43 tree species have been identified; 8 of them were alien and 5 species were cultural fruit trees. In total 20 shrub species were identified, out of which 3 were alien. Three woody species are classified as invasive according to the law in Slovakia: Acer negundo L., Ailanthus altissima (Mill.) Swingle, and Lycium barbarum L. They occurred only in 2, maximum in 4 of the evaluated habitats. The most occurring alien tree species Robinia pseudoacacia L. was generally identified in 58 habitats and in 48 habitats, with an incidence over 40% and dominance index of 70.6. The second most occurring alien tree Populus × canadensis had a dominance index of 8.3. The dominant native trees in NFWV were Acer campestre L., Fraxinus excelsior L., Quercus robur L., Salix fragilis L. with the dominance index of 1–5 only.


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