Print
First syntaxonomical contribution to the invasive Ailanthus altissima (Mill.) Swingle forest communities at its southern limit in Europe
expand article infoSilvia Montecchiari‡, Marina Allegrezza‡, Veronica Pelliccia‡, Giulio Tesei‡
‡ Marche Polytechnic University, Ancona, Italy

Corresponding author: Silvia Montecchiari ( s.montecchiari@pm.univpm.it )

Academic editor: Simonetta Bagella
© 2020 Silvia Montecchiari, Marina Allegrezza, Veronica Pelliccia, Giulio Tesei.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation: Montecchiari S, Allegrezza M, Pelliccia V, Tesei G (2020) First syntaxonomical contribution to the invasive Ailanthus altissima (Mill.) Swingle forest communities at its southern limit in Europe. Plant Sociology 57(2): 145-160. https://doi.org/10.3897/pls2020572/06
Open Access

Abstract

Ailanthus altissima (tree of heaven), an invasive alien tree native to China, has become invasive all over the world and in Italy is present in all the administrative regions where it can form dense forest communities. Although there are several ecological studies on this species there is a lack of floristic-vegetational data for southern-Europe. The study presents the results of a floristic vegetational study on A. altissima forest communities of central Italy that aims to highlight the possible floristic-vegetational autonomy of these coenoses. The results have allowed the characterization of A. altissima coenoses at the ecological, biogeographic, syntaxonomic and landscape levels. These represent first A. altissima syntaxa described for the Italian peninsula and for southern-Europe. We propose two new sub-Mediterranean and Mediterranean associations comprised in the recently described alliance Lauro nobilis-Robinion pseudoaciae, in the Chelidonio-Robinietalia order and the Robinietea class: Asparago acutifolii-Ailanthetum altissimae: forest community with stratified structure and high canopy density on the warmer slopes of the hills in dry soil conditions and low anthropic disturbance and Aro italici-Ailanthetum altissimae: paucispecific forest communities with a monolayered structure typically found in agricultural, and peri-urban areas on pelitic, alluvial silty-sandy substrates, in conditions of edaphic humidity and high anthropogenic disturbance. The comparison with literature data highlights the autonomy of these associations of the sub-Mediterranean and Mediterranean alliance Lauro nobilis-Robinion pseudoacaciae alliance from the Balloto nigrae-Ailanthetum altissimae association of the Central and SE-European Balloto nigrae-Robinion pseudoacaciae alliance.

Keywords

Ailanthus altissima, alien forest communities, invasive alien species, Mediterranean and sub-Mediterranean climate, plant landscape, Robinietea class, syntaxonomy

Introduction

The invasion of alien plants is a global process derived from the human–mediated introduction of a species outside their habitat of origin (Richardson and Pyšek 2006; Van Kleunen et al. 2015). Biological invasions constitute one of the major threats to biodiversity and ecosystem services provided by native ecosystems (Simberloff et al. 2013; Lazzaro et al. 2020; Montecchiari et al. 2020a) causing both ecological, economical and health impacts (Lonsdale 1999; Pimentel et al. 2000; Touza et al. 2008; Vilà and Hulme 2017).

Ailanthus altissima is one of the most widespread invasive alien species (IAS) in Europe (Lambdon, et al. 2008; Pysek et al. 2009) and was recently added to the list of IAS of Union concern (European commission 2019). It is a tree native to China and introduced in Europe (France) in 1740 (Kowarik and Saumel 2007). It quickly spread in Central and southern Europe in urban and peri–urban areas, but also in the agro–forest environment (Gutte et al. 1987; Udvardy 1998; Howard et al. 2004) due to cultivations for ornamental, productive and erosion control purposes (Hu 1979; Udvardy 1998; Kowarik and Säumel 2007; Badalamenti et al. 2012). Its first record for the Italian territory dates back to 1760 in the Botanical Garden of Padua (Badalamenti et al. 2012). Now is present in all the Italian administrative regions (Galasso et al. 2018) classified as invasive alien species because it can constitute proper forest communities (Montecchiari et al. 2020b; Viciani et al. 2020) capable to impact native ecosystems and Natura 2000 sites (Lazzaro et al. 2020). Moreover, according to the National Forest Inventory (Tabacchi et al. 2007), which classifies in a single category the A. altissima and R. pseudoacacia and forests, these formations together occupy almost 250000 ha, equal to 2.23% of the total national wooded area.

The efficacy in gamic reproduction and dissemination (Knapp and Canham 2000; Motard et al. 2011), agamic reproduction (Kowarik 1995; Kowarik and Saumel 2007, Von der Lippe et al. 2013) and rapid growth, enable A. altissima to form nearly pure stands (Dihoru and Doniţă 1970; Montecchiari et al. 2020b) and to have better competitive ability compared to the forest native species (Arnaboldi et al. 2002; Fotiadis et al. 2011; Höfle et al. 2014; Costàn-Nava et al. 2015). Moreover, the production of an allelopathic compound (Ailanthone) from the bark and leaves, can inhibit the germination of native species (Lawrence et al. 1991; Bostan et al. 2014). It shows a high tolerance to limiting ecological factors such as soil type and drought with several adaptations to water loss (Kowarik and Saumel 2007; Sladonja et al. 2015). A. altissima is better adapted to warmer climate regimes, in fact, it shows a high susceptibility to cold that is a limiting factor for the sapling survival (von der Lippe et al. 2005). Badalamenti et al. (2012) reports that A. altissima avoids excessively clay soils or soils subject to prolonged water stagnation. Thanks to its highly competitive features A. altissima can establish in a wide variety of environmental conditions and is able to form dense forest population that can also impact soil properties and nutrient cycling (Vilà et al. 2006; Gómez-Aparicio et al. 2008; Castro-Díez et al. 2009; Medina-Villar et al. 2015; Motard et al. 2015; Montecchiari et al. 2020b). Despite the many ecological data available and its wide distribution in the Mediterranean and Temperate Europe, there is an important lack of floristic-vegetational studies on A. altissima forests in its meridional range of distribution, in sub-Mediterranean and Mediterranean areas. From a syntaxonomic point of view, in Europe is recognized only one class (with two orders and three alliances) that comprehends alien tree species as characteristic species: the Robinietea class. It includes “seral forest-clearing and anthropogenic successional scrub and thickets on nutrient-rich soils of temperate Europe” (Mucina et al. 2016) but it includes also thermophilus and xerophilous communities such as those of the Euphorbio cyparissiae-Robinietalia order defined as “tortuous and xerophilous Black Locust stands of thermophilus habitats” and on poor soils” (Vitkova and Kolbek 2010). Recently in Allegrezza et al. (2019) was described the Lauro nobilis-Robinion pseudoacaciae alliance for the peri-Adriatic sector of Central Italy, that brings together forest and pre–forest coenoses dominated by R. pseudoacacia that include forests communities dominated by other invasive alien tree species that have developed in the Mediterranean macroclimate territories of central and southern Italy that also extend into the temperate macroclimate of the sub-Mediterranean variant. Currently, in literature, there is only one A. altissima syntaxon, described for est-Romania by Sîrbu & Oprea (2010) called Balloto nigrae-Ailanthetum altissimae. This association is referred to the Balloto nigrae-Robinion pseudoacaciae alliance, Chelidonio-Robinietalia pseudoacaciae order Robinietea class. The association comprehend A. altissima communities situated between 38 and 265 m a.s.l. near human settlements, along roadsides-railway embankments, in abandoned agricultural areas and on the edge of Robinia pseudoacacia plantations that comprehends “heliophilous (sub-heliophilous), moderate thermophilous, xero-mesophilous, neutrophilous and moderate nitrophilous phytocoenoses” (Sirbu & Oprea 2010). Also, A. altissima communities of Slovakia were referred to Balloto nigrae-Ailanthetum association by Valachovic (2018). For central-Europe, there are other published floristic-vegetation data of A. altissima coenoses but described only at the community level. Those communities have been described without a clear syntaxonomical classification and referred to syntaxonomic classes other than the Robinietea class such as Sisymbrietea, Chenopodietea, Artemisietea, Agropyretea or Urtico-Sambucetea, Cratego-Prunetea, Quercetea pubescenti–petraeae classes (Gutte et al. 1987) or described as Ailanthus-woods with R. pseudoacacia and Acer species with a non-clear syntaxonomic attribution (Kowarik and Bocker 1984). Moreover, for the Mediterranean region, Kowarik (1983) reported on the colonization by the A. altissima in the French-Mediterranean region classifying the A. altissima communities according to the Hemeroby classification system. He reported only one relevè “the only A. altissima occurrence in a non-ruderalized Quercion ilicis stand is on the northern slope of the mountain range”.

In literature is also cited A. altissima associations with no floristic-vegetational data linked to this syntaxons in literature such as Ailantho altissimae-Robinietum pseudacaciae Julve 2003 referred to Robinio pseudoacaciae-Ulmion minoris Julve 1993 alliance, Pruno avium-Carpinetalia betuli Gillet 1986 ex Julve 1993 order, Fraxino excelsioris-Quercetea roboris Gillet 1986 ex Julve 1993 class and the Fico-Ailanthetum altissimae Lov. (1975) 1984 ("Ailantho-Robinietum" auct. adriat. Pp non Gutte; Kvarner: "žiròvine").

For the Italian territory, there are only two published papers that describe A. altissima dominated vegetation: Fanelli (2002) described A. altissima forest community for the surroundings of the city of Rome and Sciandrello et al. (2017) described a Rubus ulmifolius shrub community in Sicily (Pruno spinosae-Rubion ulmifolii, Pyro spinosae-Rubetalia ulmifolii, Crataego-Prunetea) with A. altissima having cover–abundance values higher than 3 (Braun-Blanquet scale) in four relevés. In the present paper, we aimed to describe the structure, ecology and syntaxonomy of the A. altissima forest communities present in its southern limit of presence in Europe. Specifically, the aims of this syntaxonomic study are to i) extend the poor floristic-vegetational data available for A. altissima forests communities in the Italian peninsula; ii) define the A. altissima forest vegetational types at the community level and the ecological and landscape context in which they are found; iii) highlight the possible floristic-vegetational autonomy of these coenoses in the context of the Robinietea class in comparison with A. altissima floristic-vegetational data from Europe.

Study area

The study was conducted in central Italy (Marche-Abruzzo peri-Adriatic sector) (Figure 1) at altitudes that range from 10 m a.s.l. to 500 m a.s.l on pelitic-arenaceous, arenaceous-pelitic and alluvial lithotypes. The bioclimatic classification sensu Rivas-Martínez et al. (2011) for these territories indicates a Macrobioclimate that ranging from Mediterranean, pluviseasonal oceanic bioclimate and upper meso-Mediterranean thermotype to the Temperate sub-Mediterranean variant, oceanic bioclimate and lower meso-temperate thermotype (Pesaresi et al. 2014) according to the bioclimatic classification. The prevailing land use categories are mostly cops such as heterogeneous agricultural areas with complex cultivation patterns and non-irrigated arable land. The native forests vegetation consists of Quercus pubescens/Q. virgiliana woods on slopes referred to the alliance Carpinion orientalis (class Querco roboris-Fagetea sylvaticae), and riparian woods of Salix alba and Populus nigra referred to the alliance Populion albae (class Salici purpureae-Populetea nigrae). The high-shrub pre-forest vegetation is represented by Ulmus minor communities of the Lauro nobilis-Ulmion minoris alliance (class Salici purpureae-Populetea nigrae) (Blasi et al. 2010).

Figure 1. 

Study area. Location of the study area showing the distribution of the unpublished relevés. Each relevè is represented by a single black point.

Materials and Methods

The study of the plant communities was carried out according to the phytosociological methods of the Zurich–Montpellier school (Braun-Blanquet 1928), updated according to the most recent acquisitions (Rivas-Martínez 2005; Allegrezza et al. 2008; Biondi 2011; Blasi and Frondoni 2011). We performed a total of 22 unpublished phytosociological relevés. The surveys were performed on A. altissima forests aged >20 years, where the alien tree was clearly dominant and over a minimum homogeneous area of 100 m2. For the characterization of the A. altissima forests of the Italian peninsula, the unpublished relevés were analyzed along with 5 relevés from Fanelli (2002) that described A. altissima community for the surrounding of Rome, because they have a forest structure, with clearly dominant A. altissima, having cover-abundance values higher than 3 (Braun-Blanquet scale) (see Appendix II). For the comparisons between the Italian peninsula and the European context we selected literature data that have been attributed to a syntaxon that includes A. altissima in the name and clearly dominant (cover-abundance values >3). Were used a total of 25 phytosociological relevés referred to the Balloto nigrae-Ailanthetum altissimae association respectively 20 from Sirbu & Oprea (2010) 5 from Valachovic (2018). The nomenclature of the species follows the check-list of Italian flora (Bartolucci et al. 2018). The life forms and chorology of the species follow Flora d’Italia (Pignatti et al. 2017–2019). For the Ellenberg indicators values (EIVs) (Ellenberg et al. 1992), we used the indices reformulated for the Mediterranean conditions (Pignatti et al. 2005): L light, T temperatures, C continentality; U soil moisture, R soil reaction, N availability of soil nutrients. The syntaxonomic classification is made according to the Prodrome of the Italian Vegetation (Biondi et al. 2014), as present on the updated site of the Italian Botanical Society (http://www. prodromovegetazioneitalia.org/), with references to that of the European vegetation (Mucina et al. 2016). The status of alien species (specifying between Archeophytes and Neophytes) has been assigned according to Galasso et al. (2018) and information on the national floras for the European data.

Data analysis

The vegetation data were processed using the “vegan” package (Oksanen et al. 2020) of the R software (R core team 2018). The cover–abundance values of the phytosociological matrix were converted to the Van der Maarel (1979) decimal scale and subjected to multivariate analysis. Before calculations, the ecological variables matrix was undergone at a normalization process using the “decostand” function on the “vegan” package. The numerical classification according to cluster analysis was carried out by applying the “Ward” link algorithm to the similarity ratio matrix calculated by applying the “Jaccard” index on the vegetation matrix converted in presence/absence values. Life forms of each relevè were weighted on the species abundance values and then averaged at the group level. To compare EIVs of the plots, we used weighted average values. Box plot diagrams were used to illustrate data distribution of Life forms and EIVs. To analyze the variance of the groups and tests for significance we used ANOVA (supplementary materials, Table S1) (“aov” function of “stats” package). The Shapiro test was used to test the normality of the analyzed data and the Bartlett test for homoscedasticity.

For the comparison with the published European data, we create a unique phytosociological matrix, converted to the Van der Maarel (1979) decimal scale and subjected to multivariate analysis. The similarity matrix obtained applying the “Jaccard” index was used to perform non–metric multidimensional (NMDS) ordination diagram. The NMDS ordination diagram is suitable for the analysis of ordinal data such as those of Van der Maarel (Podani 2007) and was used to describe the main trends of the vegetation variations. Percentage weighted presence of chorological types and alien species for each plot was calculated and illustrated by box plots. Then we performed the analysis of variance and tested the significance among the averages of the identified groups.

Results and Discussion

The dendrogram (Fig. 2a) obtained from the classification of phytosociological relevès highlights two main groups (Cluster I and Cluster II) which correspond to the two main structural, ecological and floristic–vegetational characteristics of the A. altissima forest communities. The comparison of the statistically significant traits such as functional (life forms) and ecological traits (EIVs), highlights the structural and ecological differences between the two groups. The first group (Cluster I) differs for the higher coverage of phanerophytes (Fig. 2b.2) and thermophilous species (Temperature EIV) (Fig. 2b.4) while the second group (Cluster II) is characterized by the higher coverage of herbaceous species such as Geophytes and Terophytes (Fig. 2b.1 and 2b.3). The processing of the relevès in Table 1 and the comparison with the similar phytocoenoses described for south–est Europe allows us to propose and describe two new associations of A. altissima forest vegetation within the sub– Mediterranean alliance Lauro nobilis-Robinion pseudoacaciae (order Chelidonio-Robinietalia pseudoacaciae and class Robinietea): Asparago acutifolii-Ailanthetum altissimae (cluster I) and Aro italici-Ailanthetum altissimae (Cluster II).

Asparago acutifolii–Ailanthetum altissimae ass. nova (Cluster I Fig. 2; typus rel. 7 of Tab. 1)

It is a sub-Mediterranean and Mediterranean forest community dominated by A. altissima characterized by a stratified structure and high canopy density, with an average height of 13.6 and an average richness of 16 species per relevè. It is typically present on the warmer slopes of the hills (up to 460 m a.s.l.) with arenaceous-pelitic, arenaceous and locally calcareous substrates, in dry soil conditions and in areas subject to low anthropic disturbance (the surrounding landscape is characterized by the greater presence of forest areas). In the dominated tree and shrub layer are frequent forest species of the Querco-Fagetea class such as Hedera helix, Acer campestre, Quercus pubescens, Fraxinus ornus and pre-forest and shrub species of the Rhamno-Prunetea class such as Rubus ulmifolius, Clematis vitalba, Ulmus minor. Those species indicate that the potential native vegetation for the territory occupied by the A. altissima forest of the Asparago acutifolii-Ailanthetum altissimae is the Mediterranean and sub-Mediterranean oak forests of the Carpinion orientalis alliance, referring to the habitat of community interest 91AA (92/43/EEC Habitats Directive). Characteristic and differential species of the new association are A. altissima, Hedera helix, Acer campestre, Quercus pubescens, Fraxinus ornus, Prunus spinosa, Asparagus acutifolius and Olea europaea. The new association refers to the Lauro nobilis-Robinion pseudoacaciae alliance because of the presence of characteristic species of this syntaxon such as Rubus ulmifolius, Laurus nobilis, Melissa officinalis subsp. altissima, Rubia peregrina, Parietaria diffusa, Viola alba subsp. dehnhardtii, Ficus carica, Ligustrum vulgare, Rosa sempervirens, Rhamnus alaternus, Avena barbata, etc. The characteristic species of the order Chelidonio-Robinetalia pseudoacaciae and Robinietea class except for A. altissima (Robinietea class) are present locally and with low coverage values especially in the xerophilous aspects similarly to what happens for the thermophilous communities of the association Rubio peregrinae-Robinietum pseudoacaciae (Allegrezza et al. 2019). However, as highlighted in Allegrezza et al. (2019), the Lauro nobilis-Robinion pseudoacaciae alliance includes, in addition to the typically nitrophilous aspects on soils rich in organic matter, also xerophilous and thermophilous communities on dry soils in poorly anthropized contexts (Allegrezza et al. 2019).

Compared to the Rubio peregrinae-Robinietum pseudoacaciae association described by Allegrezza et al. (2019) for the same study area, the floristic composition of the new association Asparago acutifolii-Ailanthetum altissimae essentially differs for the lower species richness and coverage of mesophilous and nitrophilous species such as Sambucus nigra denoting for the A. altissima forests a stronger thermophilous and xerophilous character, in accordance with what is reported in the literature on the ecology of A. altissima (e.g. Sladonja et al. 2015).

Aro italici–Ailanthetum altissimae ass. nova (Cluster II Fig. 2; typus rel. 22 of Tab. 1) .

The new association refers to the A. altissima sub-Mediterranean and Mediterranean paucispecific forest communities characterized by a monolayered structure, with a with an average height of 12 m, and an average richness of 13 species per relevè. These forest coenoses are typically found in agricultural areas in correspondence with pelitic, alluvial silty-sandy substrates and peri-urban areas in conditions of edaphic humidity and high anthropogenic disturbance. The shrub layer is poor in species and it consists exclusively of Rubus ulmifolius and Clematis vitalba, even if locally can be also found Laurus nobilis and Robinia pseudoacacia. On the other hand, the herbaceous layer is locally rich in species and characterized by geophytes and transgressive hemicriptophytes of the Galio-Urticetea classes (Galium aparine, Arum italicum), Artemisietea (Elymus repens, Poa trivialis), Robinietea and terophytes of the Stellarieta mediae class (Anisantha diandra, Avena barbata) which highlight the conditions of high and constant anthropogenic disturbance. Characteristic and differential species of the new association are A. altissima, Arum italicum, Elymus repens, Convolvulus arvensis and Poa trivialis. The new association Aro italici-Ailanthetum altissimae that is referred to the Lauro nobilis-Robinion pseudoacaciae alliance (Chelidonio-Robinietalia pseudoacaciae order and Robinietea class) has floristic analogies with the R. pseudoacacia association Melisso altissimae-Robinetum pseudoacaciae widely present on alluvial plains of the Mediterranean and sub-Mediterranean region. The main differences between these two association are that the Aro italici-Ailanthetum altissimae is less common in the study area and has an extremely impoverished tree and shrub components. Furthermore, even if the Robinia forest vegetation is also found in the position of the willow groves of Salix alba (Melisso altissimae-Robinietum pseudoacaciae var. Carex pendula), in the investigated territories, the A. altissima forest vegetation is almost absent in this landscape context. This confirms what is reported in the literature on the ecology of A. altissima that does not tolerate prolonged conditions of soil water stagnation (e.g. Badalamenti et al. 2012).

Figure 2. 

Classification of the Italian A. altissima forest communities and box plots of the life forms. (a) Dendrogram from the phytosociological relevés of the A. altissima communities in the study area and published relevés from Fanelli (2002). Cluster I, Asparago acutifolii-Ailanthetum altissimae; Cluster II, Aro italici-Ailanthetum altissimae. (b) Comparison of the significant life form and EIVs of the two A. altissima forest associations (AspAil: Asparago acutifolii-Ailanthetum altissimae and AroAil: Aro italici-Ailanthetum altissimae) through box plots. (b.1) Geophytes p value <0,0001, (b.2) Phanerophytes p value <0,0001; (b.3) Terophytes p value = 0.001; (b.4) Temperature EIV p value =0.04.

Table 1.
Download as
CSV
XLSX

Mediterranean and sub-Mediterranean A. altissima forest communities belong to the alliance Lauro nobilis-Robinion pseudoacaciae. Asparago acutifolii-Ailanthetum altissimae ass. nova (rels 1–19, typus rel. 7); Aro italici-Ailanthetum altissimae ass. nova (rels 20–27, typus rel. 22).

Life form N° rel. 1 2 3 4 5 6 7* 8 9 10 11 12 13 14 15 16 17 18 19 20 22^ 21 23 24 25 26 27 Pres. Freq. Gr. I Freq. Gr. II
N° rel. from dendrogram fig. 2 29 25 20 3 21 5 23 28 18 17 19 4 16 15 22 14 94 8 11 9 10 2 1 97 96 99 95
N° cluster from dendrogram fig. 2 I I I I I I I I I I I I I I I I I I I II II II II II II II II
Altitude [m o.s.l.] 114 38 310 97 462 28 162 80 308 359 268 40 301 140 179 50 152 460 114 97 330 350
Aspect S SE S S E NO NE E E NE N SO NO SE NO SE SO NO O O E SE S O SE O NO
Slope [°] 30 10 15 30 15 20 25 35 5 15 15 20 15 15 10 10 5 35 40 - - 5 25 45 2 1 15
Area [mq] 200 100 100 90 400 350 250 250 100 100 250 150 100 250 150 300 100 150 120 200 200 100 150 80 80 80 50
Total cover [%] 90 90 90 90 85 97 95 90 90 100 95 90 95 99 85 95 98 95 95 50 100 90
Tree layer height [m] 8 13 19 8.3 10 19 20 14 11 12 20 9 13 13 8 14 20 15.8 11.4 14 8 10.5 8 15 20 15 7
N° species x rel. 17 14 19 18 16 22 23 16 15 12 17 16 25 17 7 13 14 12 17 12 14 15 14 15 11 16 13
Asparago acutifolii-Ailanthetum altissimae ass. nova
P lian Hedera helix L. 3.3 1.1 3.3 2.2 4.4 2.2 4.4 5.5 4.4 2.3 +.2 + 3.3 4 + + 1.2 1.1 18 V II
P scap Acer campestre L. + + 1.1 2.2 2.2 + + + + + 1.2 11 III
P caesp Quercus pubescens s.l. Willd. + + + + + 1.1 2.2 1.2 8 III
P scap Fraxinus ornus L. + + 1.1 + + 5 II
G rhiz Asparagus acutifolius L. 1.1 + 2.3 1.1 1.1 + 1.1 + + + 10 II II
P caesp Prunus spinosa L. 1.1 + + + + + + 1.1 8 III
P caesp Olea europaea L. + +.2 + + + 5 II
Aro italici-Ailanthetum altissimae ass. nova
G rhiz Arum italicum Mill. + 1.2 1.2 1.1 3.3 1 + + + 9 I V
G rhiz Elymus repens (L.) Gould subsp. repens 1.2 1.2 3.3 3 III
G rhiz Convolvulus arvensis L. + + + 3 III
H caesp Poa trivialis L. + + + + 4 I III
Lauro nobilis-Robinion pseudoacaciae
NP Rubus ulmifolius Schott 1.1 + + 2.2 + 2.2 2.2 + + 1.1 2.3 1.1 5.5 + + + 3.3 +.2 +.2 + + 21 V IV
P caesp Laurus nobilis L. + + 1.1 + 1.1 + + + 2 + 1.2 + 12 III II
H scap Melissa officinalis subsp. altissima + + + + + + 1.1 1.2 +.2 2.2 10 II III
P lian Rubia peregrina L. + + + 2.2 2.2 1 6 II I
H scap Parietaria diffusa M. et K. + + + +.2 + 1 6 I III
T scap Anisantha diandra (Roth) Tutin ex Tzvelev 1.1 1.1 + 1.2 1.1 5 I II
T scap Avena barbata Potter + 2.2 + 1.1 + 5 I III
H ros Viola alba Besser subsp. dehnhardtii (Ten.) W.Becker + + + +.2 4 I I
P scap Ficus carica L. +.2 1.2 + 3 I II
NP Ligustrum vulgare L. + 2.2 2 3 I
P caesp Rhamnus alaternus L. 1.2 1.1 1 3 I I
H caesp Brachypodium rupestre (Host) R. et S. + + 2 I
G bulb Bellevalia romana (L.) Sweet + 1 I
P scap Juglans regia L. + 1.1 2 I I
NP Rosa sempervirens L. + + 2 I I
H bienn Inula conyzae (Griess.) DC. + 1 I
P scap Quercus ilex L. + 1 I
G rhiz Ruscus aculeatus L. + 1 I
G rhiz Arundo plinii Turra +.3 1 I
G rhiz Chamaeiris foetidissima (L.) Medik. + 1 I
T scap Sinapis alba L. +.2 1 I
Chelidonio-Robinietalia and Robinietea
P scap Ailanthus altissima (Mill.) Swingle 4.4 3.3 3.3 4.4 4.4 5.5 3.3 4.4 4.4 5.5 4.4 4.4 5.5 4.4 4.4 4.4 5 4.4 4.5 4.4 4.4 4.4 4.4 4 5 5 5 27 V V
P caesp Sambucus nigra L. + + 3.3 + 2.2 + + 2.2 + 9 III I
T scap Galium aparine L. + 1.1 +.2 2.2 4 + + 1 8 I IV
H scap Urtica dioica L. + + + + + +.2 + 2 8 II III
P caesp Robinia pseudoacacia L. 1.1 + + 1.1 + +.2 1 7 II III
T scap Chaerophyllum temulum L. 3.3 + + + + +-2 6 II
T scap Anisantha sterilis (L.) Nevski + + + 1 2 5 I II
H bienn Alliaria petiolata (M.Bieb.) Cavara & Grande + + + + 4 I I
H scap Lamium maculatum L. + + + + 4 II
H caesp Dactylis glomerata L. + + +.2 3 I
H scap Geum urbanum L. + 1 I
T rept Stellaria media (L.) Vill. + 1 I
H scap Ballota nigra L. 1.1 1 I
G rhiz Bryonia dioica Jacq. 1 1 I
T scap Fallopia convolvulus (L.) Holub + 1 I
H scap Anthriscus sylvestris (L.) Hoffm. + 1 I
Others
P lian Clematis vitalba L. + + + + + + 3.3 + 1.1 1.1 + + + + 3.3 1.2 +.2 + 1.1 19 IV III
P caesp Crataegus monogyna Jacq. + + + + + 1.1 + + + + + + 12 III II
P scap Prunus avium (L.) L. + + + 1.1 4 II
P caesp Cornus sanguinea L. + + + 1.1 2.2 + 1.1 + +.2 1.2 + 11 III II
P caesp Ulmus minor Miller + + + 2.2 + 2.2 + 1.2 + 9 III I
P caesp Euonymus europaeus L. 1.1 + + 1.1 + + 1.1 + +.2 9 III I
H scap Clinopodium nepeta (L.) Kuntze + + 1.1 +.3 4 II
P caesp Paliurus spina christi Miller 1.1 + + 3 I
H scap Galium album Miller + + + 3 I
H caesp Brachypodium sylvaticum (Huds.) Beauv. 5.5 1.1 + 3 I I
P scap Cercis siliquastrum L. + 1.1 2 I
NP Rubus caesius L. 1.1 + 2 I I
H scap Picris hieracioides L. + + 2 I
NP Osyris alba L. + + 2 I
T scap Torilis arvensis (Hudson) Link 1.1 + 2 I
H scap Rumex obtusifolius L. + + 2 II
P caesp Prunus domestica L. + + 2 I
NP Rosa canina L. 1.1 + 2 I
H scap Cruciata glabra (L.) Ehrend. +.2 + 2 I
H ros Silene italica (L.) Pers. + + 2 I
H caesp Carex pendula Huds. + + 2 I I
P lian Lonicera japonica Thunb. 3.2 1 2 I I
G rhiz Arundo donax L. + + 2 I I
H bienn Silene latifolia Poiret + + 2 I I
H scap Stachys sylvatica L. + + 2 I I
P scap Populus nigra L. + +.2 2 I I
Sporadics species 1 1 5 6 4 3 2 - 1 - - - 3 4 - 1 2 1 1 - - 2 - 5 2 2 3

Comparison of A. altissima communities in Europe and in the Mediterranean and sub– Mediterranean areas

The NMDS ordination plot (Fig. 3a) of the A. altissima forest coenoses here considered along with those from SE-Europe, highlights the separation into two distinct groups. The first group corresponds to the two new associations here proposed: Asparago acutifolii–Ailanthetum altissimae and Aro italici-Ailanthetum altissimae of the sub-Mediterranean and Mediterranean alliance Lauro nobilis-Robinion pseudoacaciae, while the second group corresponds to the Balloto nigrae-Ailanthetum altissimae association of the Balloto nigrae-Robinion pseudoacaciae alliance with a south-eastern European range. The floristic differentiation between the two groups is mainly determined by the syn-chorology. The statistically significant chorological elements (Fig. 3b) were the Mediterranean and Boreal chorotypes and the weighted presence of naturalized (archaeophytes) and invasive (neophytes) species. The Mediterranean chorotype (Fig. 3b.1) is linked to the syntaxa of the Lauro nobilis-Robinion pseudoacaciae alliance while the Boreal chorotype (Fig. 3b.2) and the presence of archeophyte and neophyte alien species (Fig. 3b.4) characterize the Balloto nigrae-Ailanthetum altissimae association of the Balloto nigrae-Robinion pseudoacaciae alliance. As can be seen in the Synoptic table reported in Table 2, the Lauro nobilis-Robinion pseudoacaciae alliance recently described for the sub-Mediterranean and Mediterranean forest communities of Robinia pseudoacacia confirms its floristic autonomy with respect to the analogous coenoses described for the center and SE–Europe, also for the A. altissima forest coenoses present at their southern limit of distribution in Europe. Even if not considered in the data processing of this work (not forest structure), the shrub communities of A. altissima and Rubus ulmifolius found in Sicily (Sciandrello et al. 2016) can also be referred to the same alliance. The Lauro nobilis-Robinion pseudoacaciaciae alliance could also be extended to A. altissima forest communities present in the Mediterranean and sub-Mediterranean areas of France. It can be done thanks to the only phytosociological relevè reported in Kowarik (1983) in which A. altissima communities with Quercus ilex of the territory of Collies (South France) shows floristic and ecological analogies with the more xerophilic elements of the Asparago acutifolii-Ailanthetum altissimae here proposed. At the landscape level, the sub-Mediterranean and Mediterranean A. altissima forest communities are mainly found in the forest landscape of the order Quercetalia pubescentis-petraeae with the alliances Carpinion orientalis and locally with those of Quercetea ilicis for the more xerophilic aspects. As regards the relationships with the similar sub-Mediterranean R. pseudoacacia of forest coenoses of the Lauro nobilis-Robinion pseudoacaciae alliance described above: Rubio peregrinae-Robinietum pseudoacaciae and Melisso altissimae-Robinietum pseudoacaciae, it is noted that the A. altissima forest vegetation is less widespread in the investigated territory but it prevails over R. pseudoacacia forests in the more xerophilous slope conditions on dry soil (Asparago acutifolii-Ailanthetum altissimae) while the R. pseudoacacia forest vegetation is mainly distributed along the river basins, on the recent alluvial loamy-sandy terraces and in the river beds (Melisso altissimae-Robinietum pseudoacaciae) where the A. altissima forests are almost absent. The distribution of A. altissima and R. pseudoacacia forests is mainly connected to the different ecology of the two dominant invasive alien species. As reported in the literature, A. altissima is a thermophilous species, adapted to edaphic aridity but it is limited by low temperatures and water stagnation (Kowarik 1983; Trifilò et al. 2004; Kowarik and Saumel 2007). As can be seen from the Table 2, the impoverishment of the species of the order Chelidonio-Robinietalia and the Robinietea class in the Mediterranean area mainly concerns the A. altissima communities present in the most xerophilous areas with low anthropic disturbance. However, this is similar to what happens for the xerophilous and thermophilous communities of the order Euphorbio cyparissiae-Robinietalia of the class Robinietea shown in Vitkova and Kolbek (2010). Moreover, from an ecological point of view, the differences between A. altissima forests and the neighboring native forests were highlighted and proved for both R. pseudoacacia (Montecchiari et al. 2020a) and A. altissima forests (Montecchiari et al. 2020b). A great effort has been made in Europe to classify alien-dominated forest communities that previously were referred to different orders and classes. Therefore, at the current state of knowledge, the attribution to the Robinietea class seems to be the only way forward. Future studies in the Mediterranean area will better clarify the syntaxonomic position of the A. altissima communities of the Lauro nobilis-Robinion pseudoacaciae alliance currently belonging to the order Chelidonio-Robinietalia of the Robinietea class and also to better clarify the syntaxonomic framework of the Robinietea class in Europe.

Table 2.
Download as
CSV
XLSX

Synoptic table of A. altissima communities in Europe. Asparago acutifolii-Ailanthetum altissimae ass. nova (column 1); Aro italici-Ailanthetum altissimae ass. nova (column 2); Balloto nigrae-Ailanthetum altissimae (column 3).

Life form Chorotype N. columns 1 2 3 Pres.
N. rels. per column 19 8 25
Asparago acutifolii-Ailanthetum altissimae ass. nova
P lian Eur./SW-Asiat. Hedera helix L. V II . 2
G rhiz Medit. Asparagus acutifolius L. II II . 2
P caesp S-Eur. Quercus pubescens Willd. III . . 1
P caesp Medit. Olea europaea L. II . . 1
P scap S-Eur./W-Asiat. Fraxinus ornus L. II . . 1
P caesp Eur./W-Asiat. Prunus spinosa L. III . I 2
P scap Eur./W-Asiat. Acer campestre L. III . I 2
Aro italici-Ailanthetum altissimae ass. nova
G rhiz Medit. Arum italicum Miller I V . 2
G rhiz Circumbor. Elymus repens (L.) Gould subsp. repens III V 2
G rhiz S-Eur./W-Asiat. Convolvulus arvensis L. III I 2
H caesp Eurasiat./N-Am. Poa trivialis L. I III I 3
Lauro nobilis-Robinion pseudoacaciae
NP Euri-Medit. Eur. Rubus ulmifolius Schott V IV . 2
P caesp Medit. Laurus nobilis L. III II . 2
H scap Steno-Medit. Melissa officinalis subsp. altissima II III . 2
P lian W-Eur./Medit. Rubia peregrina L. II I . 2
H scap W-Eur./Medit. Parietaria diffusa M. et K. I III . 2
T scap Medit. Anisantha diandra (Roth) Tutin ex Tzvelev I II . 2
T scap Medit./SW-Asiat. Avena barbata Potter I III . 2
H ros Medit. Viola alba Besser subsp. dehnhardtii (Ten.) W.Becker I I . 2
P scap Medit./SW-Asiat. Ficus carica L. I II . 2
P caesp Medit. Rhamnus alaternus L. I I . 2
NP Medit. Rosa sempervirens L. I I . 2
NP Eur./W-Asiat. Ligustrum vulgare L. I . I 2
H caesp Eur. Brachypodium rupestre (Host) R. et S. I . . 1
G bulb Medit. Bellevalia romana (L.) Sweet I . . 1
P scap SE-Eur./SW-Asiat. Juglans regia L. I I I 3
H bienn Eurasiat./N-Afr. Inula conyzae (Griess.) DC. I . . 1
P scap Medit. Quercus ilex L. I . . 1
G rhiz Medit. Ruscus aculeatus L. I . . 1
G rhiz Steno-Medit Arundo plinii Turra I . . 1
G rhiz SW-Eur. Chamaeiris foetidissima (L.) Medik. I . . 1
T scap Euri-Medit. Sinapis alba L. I I 2
Balloto nigrae-Ailanthetum altissimae and Balloto nigrae-Robinion pseudoacaciae
T scap Medit. Bromus sterilis L. I II IV 3
H caesp Eurasiat. Dactylis glomerata L. I . I 2
H scap Medit. Ballota nigra L. . I V 2
H bienn S-Eur. Lactuca serriola L. . . II 1
H caesp Circumbor. Poa angustifolia L. . . I 1
H caesp Paleotemp. Arrhenatherum elatius (L.) Presl. . . I 1
H caesp Eurosib. Calamagrostis epigejos (L.) Roth . . I 1
H bienn Eurasiat. Cynoglossum officinale L. . . I 1
H scap Circumbor. Artemisia vulgaris L. . . III 1
H bienn Eurasiat. Arctium lappa L. . . II 1
H scap A. Nat. Leonurus cardiaca L. . . II 1
Ch rept Circumbor. Glechoma hederacea L. . . II 1
NP N. Nat. Lycium barbarum L. . . I 1
Ch suffr Sub-Cosmop. Artemisia absinthium L. . . II 1
T scap Circumbor. Atriplex patula L. . . II 1
G rhiz Medit. Sambucus ebulus L. . . II 1
H scap Eur. Parietaria officinalis L. . . I 1
H scap N. Inv. Solidago canadensis L. . . I 1
Chelidonio-Robinietalia pseudoacaciae and Robinietea
P scap N. Inv. Ailanthus altissima (Mill.) Swingle V V V 3
P caesp Eur. Sambucus nigra L. III I I 3
T scap Eurasiat. Galium aparine L. I IV III 3
H scap Subcosmop. Urtica dioica L. II III III 3
P caesp N-Am. Robinia pseudoacacia L. II III II 3
H bienn Eur./W-Asiat. Alliaria petiolata (M.Bieb.) Cavara & Grande I I I 3
T scap Eur. Chaerophyllum temulum L. II . I 2
H scap Eur./W-Asiat. Lamium maculatum L. II . . 1
P lian Eur. Humulus lupulus L. . . II 1
H scap Eurasiat. Geum urbanum L. I . II 2
T rept Medit. Stellaria media (L.) Vill. . I I 2
T scap Circumbor. Fallopia convolvulus (L.) Holub . I I 2
H scap Paleotemp. Anthriscus sylvestris (L.) Hoffm. . I I 2
H scap Medit. Bryonia dioica Jacq. . I . 1
G rhiz N. Inv. Impatiens parviflora DC. . . I 1
H ros Circumbor. Taraxacum officinale Weber gr. . . I 1
H scap Eurasiat. Chelidonium majus L. . . I 1
H scap Eurasiat. Alkekengi officinarum Moench . . I 1
P scap N. Inv. Acer negundo L. . . I 1
T scap Eurasiat. Moehringia trinervia (L.) Clairv. . . I 1
T scap A. Nat. Anthriscus cerefolium (L.) Hoffm. . . I 1
P caesp N. Nat. Gleditsia triacanthos L. . . I 1
P caesp A. Nat. Prunus cerasifera Ehrh. . . I 1
H scap N. Inv. Solidago gigantea Aiton . . I 1
Others
P lian Eur. Clematis vitalba L. IV III II 3
P caesp Eur./W-Asiat. Crataegus monogyna Jacq. III II I 3
P caesp Eur. Cornus sanguinea L. III II I 3
P caesp Eur. Ulmus minor Miller III I I 3
P caesp Eur. Euonymus europaeus L. III I I 3
H caesp Eurasiat. Brachypodium sylvaticum (Huds.) Beauv. I I I 3
NP Eurasiat. Rubus caesius L. I I II 3
H scap Eurosib. Stachys sylvatica L. I I I 3
H caesp Eurasiat. Carex pendula Huds. I I . 2
P lian N. Inv. Lonicera japonica Thunb. I I . 2
G rhiz A. Inv. Arundo donax L. I I . 2
H bienn Eurasiat. Silene latifolia Poiret I I . 2
P scap Eurasiat. Populus nigra L. I I . 2
NP Eur. Rosa canina L. I . II 2
H scap Eurosib. Picris hieracioides L. I . I 2
T scap Subcosmop. Torilis arvensis (Hudson) Link I . I 2
H bienn Paleotemp. Daucus carota L. I . I 2
T scap N. Inv. Erigeron canadensis L. I . I 2
H scap Medit. Galium mollugo L. I . I 2
H scap Circumbor. Clinopodium vulgare L. I . I 2
H scap Eur. Rumex obtusifolius L. . II I 2
H scap Paleotemp. Conium maculatum L. . I II 2
P scap Eur./W-Asiat. Prunus avium (L.) L. II . . 1
H scap Medit. Clinopodium nepeta (L.) Kuntze II . . 1
H scap Subcosmop. Agrimonia eupatoria L. . . II 1
H bienne Eur. Carduus acanthoides L. . . II 1
T scap N. Inv. Erigeron annuus (L.) Desf. . . II 1
H scap Eurasiat. Tanacetum vulgare L. . . II 1
T scap Sub-Cosmop. Chenopodium album L. . . II 1
Sporadic species 35 13 98
Figure 3. 

Ordination of the Italian and SE–European A. altissima forest associations and Box plots of chorological types. (a) NMDS scaling ordination plot (clusters are superimposed to NMDS plot) of the A. altissima forest coenoses here considered (dashed line) and Balloto nigrae-Ailanthetum altissimae from SE–Europe (continue line). Legend: Circles: Aro italici-Ailanthetum altissimae; Squares: Asparago acutifolii-Ailanthetum altissimae; Triangles: Balloto nigrae-Ailanthetum altissimae. (b) Comparison of the significant chorological types (weighted percentage values) between the new Italian A. altissima forest associations considered altogether (labelled as 1) and the Balloto nigrae-Ailathetum altissimae association (labelled as 2). (b.1) Mediterranean chorotype p value=2.84e–11; (b.2) Boreal chorotype p value=3.26e–11; (b.3) Wide distribution chorotype p value=1.95e–05; (b.4) Alien species (neophytes and archeopytes) p value =3.55e–10.

Syntaxonomic scheme

Robinietea Jurko ex Hadac et Sofron1980

Chelidonio-Robinietalia pseudoacaciae Jurko ex Hadac et Sofron 1980

Lauro nobilis-Robinion pseudoacaciae Allegrezza, Montecchiari, Ottaviani, Pelliccia & Tesei 2019

Asparago acutifolii-Ailanthetum altissimae ass. nova

Aro italici-Ailanthetum altissimae ass. nova

Other syntaxa quoted in the text

Agropyretea repentis Oberdorfer, Muller & Gors in Oberdorfer, Gors, Korneck, Lohmeyer, Muller, Philippi & Seibert 1967; Ailantho altissimae-Robinietum pseudacaciae Julve 2003; Artemisietea vulgaris Lohmeyer, Preising & Tüxen ex von Rochow 1951; Balloto nigrae-Ailanthetum altissimae Sîrbu & Oprea 2010; Balloto nigrae-Robinion pseudoacaciae Hadač & Sofron 1980; Carpinion orientalis Horvat 1958; Chenopodietea Br.-Bl. in Br.- Bl., Roussine & Negre 1952 p.p.; Cratego-Prunetea Tuxen 1962; Euphorbio cyparissiae-Robinietalia Vítková in Kolbek et al. 2003; Fico-Ailanthetum altissimae Lov. (1975) 1984 ("Ailantho-Robinietum" auct. adriat. pp non Gutte; Kvarner: "žiròvine"); Fraxino excelsioris-Quercetea roboris Gillet 1986 ex Julve 1993 class; Galio-Urticetea Passarge ex Kopecky´ 1969; Lauro nobilis-Ulmion minoris Biondi, Casavecchia, Gasparri & Pesaresi in Biondi, Allegrezza, Casavecchia, Galdenzi, Gasparri, Pesaresi, Poldini, Sburlino, Vagge & Venanzoni 2015; Melisso altissimae-Robinetum pseudoacaciae Allegrezza, Montecchiari, Ottaviani, Pelliccia & Tesei 2019; Pruno avium-Carpinetalia betuli Gillet 1986 ex Julve 1993; Pruno spinosae-Rubion ulmifolii O. Bolos 1954; Pyro spinosae-Rubetalia ulmifolii Biondi, Blasi & Casavecchia in Biondi, Allegrezza, Casavecchia, Galdenzi, Gasparri, Pesaresi, Vagge & Blasi 2014; Quercetalia pubescentis-petraeae Klika 1933; Quercetea pubescenti–petrae Jakucs 1960; Quercion ilicis Br.-Bl. ex Molinier 1934; Querco roboris-Fagetea sylvaticae Br.-Bl. & Vlieger in Vlieger 1937; Rhamno-Prunetea Rivas Goday & Borja ex Tuxen 1962; Robinio pseudoacaciae-Ulmion minoris Julve 1993; Rubio peregrinae-Robinietum pseudoacaciae Allegrezza, Montecchiari, Ottaviani, Pelliccia & Tesei 2019; Salici purpureae-Populetea nigrae Rivas-Martínez & Cantò ex Rivas-Martínez, Bàscones, T.E. Dìaz, Fernàndez-Gonzàlez & Loidi 2001; Sisymbrietea Gutte & Hilbig 1975; Stellarietea mediae Tuxen, Lohmeyer & Preising ex Von Rochow 1951; Urtico-Sambucetea Passarge & Hofmann 1968.

Funding

The authors have no funding to report.

Competing interests

The authors have declared that no competing interests exist.

Acknowledgements

The authors have no support to report.

Bibliography

  • Allegrezza M, Montecchiari S, Ottaviani C, Pelliccia Tesei G (2019) Syntaxonomy of the Robinia pseudoacacia communities in the central peri–Adriatic sector of the Italian peninsula. Plant Biosystems – An International Journal Dealing with all Aspects of Plant Biology 153: 616–623. https://doi.org/10.1080/11263504.2019.1610108
  • Allegrezza M, Biondi E, Mentoni M (2008) Iso–orogeosigmeta e iso–orogeoserie nella dorsale calcarea del Monte San Vicino (Appennino centrale). Fitosociologia 45(1): 29–37
  • Arnaboldi F, Conedera M, Maspoli G (2002) Distribuzione e potenziale invasivo di A. altissima (Mill.) Swingle nel Ticino centrale. Bollettino della Società ticinese di Scienze naturali 90(1–2): 93–101.
  • Badalamenti E, Barone E, Salvatore P, Sala G (2012) A. altissima (Mill.) Swingle (Simaroubaceae) in Sicily and historical notes on its introduction in Italy (Italian). Naturalista Siciliano 36(1): 117–164.
  • Bartolucci F, Peruzzi L, Galasso G, Albano A, Alessandrini A, Ardenghi NMG, Astuti G, Bacchetta G, Ballelli S, Banfi E, et al. (2018) An updated checklist of the vascular flora native to Italy. Plant Biosystems – An International Journal Dealing with all Aspects of Plant Biology 152(2): 79–303.
  • Biondi E, Blasi C, Allegrezza M, Anzellotti I, Azzella MM, Carli E, et al. (2014) Plant communities of Italy: the vegetation prodrome Plant Biosystems – An International Journal Dealing with all Aspects of Plant Biology 148(4):728– 814.
  • Biondi E (2011) Phytosociology today: Methodological and conceptual evolution. Plant Biosystems – An International Journal Dealing with all Aspects of Plant Biology 145(1): 19–29.
  • Blasi C editor. (2010) Vegetation of Italy (Italian). Roma, IT: Palombi & Partner S.r.l.
  • Blasi R, Frondoni C. (2011) Modern perspectives for plant sociology: the case of ecological land classification and the ecoregions of Italy. Plant Biosystems – An International Journal Dealing with all Aspects of Plant Biology 145(supp1): 30–37.
  • Bostan C, Borlea F, Mihoc C, Selesan M. (2014) A. altissima species invasion on biodiversity caused by potential allelopathy. Research Journal of Agricultural Science 46(1): 95–103.
  • Braun‐Blanquet J (1928) Plant Sociology. Basics of Vegetation Science (German); Springer: Berlin/Heidelberg, Germany.
  • Castro-Díez P, González-Muñoz N, Alonso A, Gallardo A, Poorter L (2009) Effects of exotic invasive trees on nitrogen cycling: a case study in Central Spain. Biological Invasions 11: 1973–1986. https://doi.org/10.1007/s10530–008–9374–3
  • Commission Implementing Regulation (EU) 2019/1262 of 25 July 2019 amending Implementing Regulation (EU) 2016/1141 to update the list of invasive alien species of Union concern. https://eur–lex.europa.eu/legal
  • Costàn-Nava S, Soliveres S, Torices R, Serra L, Bonet A (2015) Direct and indirect effects of invasion by the alien tree A. altissima on riparian plant communities and ecosystem multifunctionality. Biological Invasions 17: 1095–1108. https://doi.org/10.1007/s10530–014–0780–4
  • Dihoru G, Doniţă N (1970) Flora şi vegetaţia Podişului Babadag (Flora and vegetation of the Babadag Plateau). Bucureşti, Edit. Acad. R. S. România, 338 pp.
  • Ellenberg H, Weber HE, Dull R, Wirth V, Werner W, Paulissen D (1992) Zeigerwerte von Pflanzen in Mitteleuropa [Pointer values of plants in Central Europe]. Scripta Geobot. 18: 1–248
  • Fanelli G (2002) Analisi fitosociologica dell’area metropolitana di Roma. Braun-Blanquetia 27: 3–269.
  • Fotiadis G, Kyriazopoulos AP, Fraggakis I (2011) The behaviour of A. altissima weed and its effects on natural ecosystems. Journal of Environmental Biology 32(6): 801–806.
  • Galasso G, Conti F, Peruzzi L, Ardenghi NMG, Banfi E, Celesti-Grapow L, Albano A, Alessandrini A, Bacchetta G, Ballelli S, et al. (2018) An updated checklist of the vascular flora alien to Italy. Plant Biosystems – An International Journal Dealing with all Aspects of Plant Biology 152(3): 556–592. https://doi.org/10.1080/11263504.2018.1441197
  • Gómez-Aparicio L, Canham CD (2008) Neighborhood models of the effects of invasive tree species on ecosystem processes. Ecological Monographs 78(1): 69–86. https://doi.org/10.1890/06–2036.1
  • Gutte P, Klotz S, Lahr C, Trefflich A (1987) A. altissima (Mill.) Swingle. A comparative study of plant geography (German). Folia Geobotanica et Phytotaxonomica 22(3): 241–262.
  • Höfle R, Dullinger S, Essl F (2014) Different factors affect the local distribution, persistence and spread of alien tree species in floodplain forests. Basic and Applied Ecology 15: 26–434. https://doi.org/10.1016/j.baae.2014.07.007
  • Hu S (1979) Ailanthus. Arnoldia 39(2): 29–50.
  • Knapp LB, Canham CD (2000) Invasion of an old–growth forest in New York by A. altissima: sapling growth and recruitment in canopy gaps. Journal of the Torey Botanical Society 127(4): 307–315.
  • Kowarik I (1995) Clonal growth in A. altissima. Journal of Vegetation Science 6: 853–856.
  • Kowarik I (1983) Colonization by the tree of heaven (A. altissima) in the French Mediterranean region (Bas–Languedoc), and its phytosociological characteristics. Phytocoenologia 11: 389–405.
  • Kowarik I, Säumel I (2007) Biological flora of Central Europe: A. altissima (Mill.) Swingle. Perspectives in Plant Ecology, Evolution and Systematics 8: 207–237.
  • Kowarik I, Bocker R (1984) Zur Verbreitung, Vergesellschaftung und Einburgerung des Gotterbaumes (A. altissima (Mill.) Swingle) in Mitteleuropa (German). Tuxenia 4: 9–29.
  • Lambdon PW, Pyšek P, Basnou C, Hejda M, Arianoutsou M, Essl F, Jarošík V, Pergl J, Winter M, Anastasiu P, et al (2008) Alien flora of Europe: Species diversity, temporal trends, geographical patterns and research needs. Preslia, 80: 101–149.
  • Lawrence JG, Colwell A, Sexton OJ (1991) The ecological impact of allelopathy in A. altissima (Simaroubaceae). American Journal of Botany 78(7): 948–958.
  • Lazzaro L, Bolpagni R, Buffa G, Gentili R, Lonati M, Stinca A, Acosta ATR, Adorni M, Aleffi M, Allegrezza M, et al. (2020) Impact of invasive alien plants on native plant communities and Natura 2000 habitats: State of the art, gap analysis and perspectives in Italy. Journal of Environmental Management 274: 111–140. https://doi.org/10.1016/j.jenvman.2020.111140)
  • Lonsdale WM (1999) Global pattern of plant invasions and the concept of invasibility. Ecology 80: 1522–1536
  • Medina-Villar S, Castro-Díez P, Alonso A, Cabra-Rivas I, Parker IM, Pérez-Corona E (2015) Do the invasive trees, A. altissima and Robinia pseudoacacia, alter litterfall dynamics and soil properties of riparian ecosystems in Central Spain? Plant Soil 396: 311–324. https://doi.org/10.1007/s11104–015–2592–4
  • Montecchiari S, Tesei G, Allegrezza M (2020a) Effects of Robinia pseudoacacia coverage on diversity and environmental conditions of central-northern Italian Quercus pubescens sub-Mediterranean forests (habitat code 91AA*): a threshold assessment. Annali di Botanica–Coenology and Plant Ecology 10: 33–54. https://doi.org/10.13133/2239–3129/16447
  • Montecchiari S, Tesei G, Allegrezza M (2020b) A. altissima forests determine a shift in herbaceous layer richness: a paired comparison with hardwood native forests in sub– Mediterranean Europe. Plants 9: 1404. https://doi.org/10.3390/plants9101404
  • Motard E, Dusz S, Geslin B, Akpa-Vinceslas M, Hignard C, Babiar O, Clair-Maczulajtys D, Michel-Salzat A, et al. (2015) How invasion by A. altissima transforms soil and litter communities in a temperate forest ecosystem. Biological Invasions 17: 1871–1832. https://doi.org/10.1007/s10530–014–0838
  • Motard E, Muratet A, Clair-Maczulajtys D, MacHon N (2011) Does the invasive species A. altissima threaten floristic diversity of temperate peri-urban forests? Comptes Rendus Biologies 334:872–879. https://doi.org/10.1016/j.crvi.2011.06.003
  • Mucina L, Bultmann H, Dierßen K, Theurillat JP, Raus T, Carni A, Sumberova K, Willner W, Dengler J, Gavilan GR, et al. (2016) Vegetation of Europe: hierarchical floristic classification system of vascular plant, bryophyte, lichen, and algal communities. Applied Vegetation Science 19: 3–264.
  • Oksanen, J.; Blanchet, F.G.; Friendly, M.; Kindt, R.; Legendre, P.; McGlinn, D.; Minchin, P.R.; O’Hara, R.B.; Simpson, G.L.; Solymos, P.; et al. Vegan: Community Ecology Package. R Package Version 2.5–3. Available online: https://cran.r–project.org/package=vegan (accessed on 1 April 2020).
  • Pignatti S, Guarino R, La Rosa M (2017–2019) Flora d’Italia, II ed. Edagricole, Bologna.
  • Pignatti S, Menegoni P, Pietrosanti S (2005) Biondicazione attraverso le piante vascolari. Valori di indicazione secondo Ellenberg (Zeigerwerte) per le specie della Flora d’Italia [Bioindication through the vascular plants. Indicator values according Ellenberg (Pointer values) for the species of the Flora of Italy]. Braun–Blanquetia. 39: 1–97.
  • Pesaresi S, Galdenzi D, Biondi E, Casavecchia S (2014) Bioclimate of Italy: application of the worldwide bioclimatic classification system. Journal of Maps 10(4): 538–553.
  • Podani J (2007) Analisi ed esplorazione multivariata dei dati in ecologia e biologia. Liguori Editore, Napoli.
  • Pyšek P, Lambdon PW, Arianoutsou M, Kühn I, Pino J, Winter M (2009) Alien vascular plants of Europe. In: Hulme PE, Nentwig W, Pyšek P, Vila M (eds) Handbook of alien species in Europe. Springer, Berlin, pp 43–61.
  • Richardson DM, Pyšek P (2006) Plant invasions: merging the concepts of species invasiveness and community invasibility. Progress in Physical Geography 30: 409–431.
  • Rivas–Martínez S (2005) Notions on dynamic catenal phytosociology as a basis of landscape science. Plant Biosystems – An International Journal Dealing with all Aspects of Plant Biology 139(2): 135–144
  • Sciandrello S, Minissale P, Sturiale G (2016) Plant communities supported by the geological setting: the case history of the Isole dei Ciclopi (east Sicily). Lazaroa 38: 27–51. https://doi.org/10.5209/LAZAROA.47929
  • Simberloff D, Martin JL, Genovesi P, Maris V, Wardle DA, Aronson J, Courchamp F, Galil B, García-Berthou E, Pascal M, Pyšek P, Sousa R, Tabacchi E, Vilà M (2013) Impacts of biological invasions: what’s what and the way forward. Trends in Ecology & Evolution 28: 58–66. https://doi.org/10.1016/j.tree.2012.07.013
  • Sirbu C, Oprea A (2010) Contribution to the study of plant communities dominated by A. altissima (Mill.) Swingle in the eastern Romania (Moldavia). Cercetări Agronomice în Moldova 44(3/147): 51–74.
  • Sladonja B, Sušek M, Guillermic J (2015) Review on Invasive Tree of Heaven (A. altissima (Mill.) Swingle) Conflicting Values: Assessment of Its Ecosystem Services and Potential Biological Threat. Environmental Management 56: 1009–1034. https://doi.org/10.1007/s00267–015–0546–5
  • Tabacchi G, De Natale F, D Cosmo L, Floris A, Gagliano C, Gasparini P, Genchi L, Scrinzi G, Tosi V (2007) Le stime di superficie 2005 – prima parte. [The 2005 area estimates – Part one]. Trento (Italy): Inventario Nazionale delle Foreste e dei Serbatoi Forestali di Carbonio. MiPAF – Corpo Forestale dello Stato – Ispettorato Generale, CRA – ISAFA. URL http://www.infc.it
  • Trifilò P, Raimondo F, Nardini A, Lo Gullo MA, Salleo S (2004) Drought resistance of A. altissima: root hydraulics and water relations. Tree Physiology 24: 107–114. https://doi.org/10.1093/treephys/24.1.107
  • Touza J, Dehnen–Schmutz K, Jones G (2008) Economic Analysis of Invasive Species Policies. In: Nentwig W. (eds) Biological Invasions. Ecological Studies (Analysis and Synthesis), vol 193. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978–3–540– 36920–2_20
  • Udvardy L (1998) Spreading and Coenological circumstances of the tree of heaven (A. altissima) in Hungary. Acta Botanica Hungarica 41: 229–314
  • Valachovic M (2018) Overlooked community with A. altissima in Slovakia (in Slovak). Bulletin Slovenskej botanickej spoločnosti 40(2): 157–161.
  • Van Kleunen M, Dawson W, Essl F, Pergl J, Winter M, Weber E et al. (2015) Global exchange and accumulation of non–native plants. Nature 525: 100–103.
  • Viciani D, Vidali M, Gigante D, Bolpagni R, Villani M, Acosta ATR, et al. (2020) A first checklist of the alien–dominated vegetation in Italy. Plant Sociology 57(1): 29–54. https://doi.org/10.3897/pls2020571/04
  • Vilà M, Tessier M, Suehs CM, Brundu G, Carta L, Galanidis A, Lambdon P, Manca M, Médail F, Moragues E, et al. (2006) Local and regional assessments of the impacts of plant invaders on vegetation structure and soil properties of Mediterranean islands. Journal of Biogeography 33: 853–861. https://doi.org/10.1111/j.1365–2699.2005.01430.x
  • Van der Maarel E (1979) Transformation of cover-abundance values in phytosociology and its effect on community similarity. Vegetatio 39(2): 97–114.
  • von der Lippe M, Saumel I, Kowarik I (2005) Cities as drivers of biological invasions. The role of climate changes and traffic. Erde 136(2): 123–143

Appendixes

Appendix I - Sporadic species

Table 1 - Rel. 1 : Allium sp. +; rel. 2: Daucus carota L. +; rel. 3: Pseudoturritis turrita (L.) Al-Shehbaz +; Iris germanica L. +, Lunaria annua L. +, Malus sp. +, Narcissus sp. +; rel. 4: Ampelodesmos mauritanicus (Poir.) T.Durand & Schinz 3.4; Colutea arborescens L. 1.2; Lagurus ovatus L. +, Tordylium apulum L. +.2, Verbascum sinuatum L. +, Erigeron canadensis L. +; rel. 5: Spartium junceum L. +; Bunium bulbocastanum L. +, Helleborus foetidus L. +, Origanum vulgare L. +.2; rel. 6: Artemisia campestris L. +; Geranium dissectum L. +, Umbilicus horizontalis (Guss.) DC. +; rel. 7: Acer pseudoplatanus L. +; Viburnum tinus L. +; rel. 9: Lonicera caprifolium L. +; rel. 13: Cruciata laevipes Opiz +, Mentha spicata L. +, Clinopodium vulgare L. +; rel. 14: Ligustrum lucidum W.T.Aiton +, Pyrus communis L. +, Verbascum thapsus L. +, Galium mollugo L. +; rel. 16: Populus alba L. +; rel. 18: Rumex cfr sanguineus +; rel. 19: Corylus avellana L. +; rel. 21: Artemisia verlotiorum Lamotte +.2, Ligustrum japonicum Thunb. +.

Appendix II - Relevès dates, localities and geographical coordinates (WGS84–UTM T33)

Table 1 - Rel. 1: 10/10/2019, Fossombrone (PU), Loc. San Lazzaro, 321483 E; 4839316 N; 33 T; Rel. 2: 01/10/2019, Fano (PU), Loc. Falcineto, 337141 E; 4848681 N; 33 T; rel. 3: 20/09/2019, Caldarola (MC), 349941 E; 4777643 N; 33 T; rel. 4: 12/10/2020, Marina di Massignano (AP), 405620 E; 4767840 N; 33 T; rel. 5: 24/09/2019, Serra san Quirico (AN), 338904 E; 4811611 N; 33 T; rel. 6: 19/06/2019, Castelfidardo (AN), 385604 E; 4814288 N; 33 T; rel. 7: 01/10/2019, Fano (PU), Loc. Monte Giove, 337132 E; 4853921 N; 33 T; rel. 8: 10/10/2019, Colli al Metauro (PU), Loc. Tavernelle, 329718 E; 4844106 N; 33 T; rel. 9: 10/09/2019, Fabriano (AN), Loc. san Michele, 333757 E; 4797518 N; 33 T; rel. 10: 10/09/2019, Fabriano (AN), Loc. san Michele, 334511 E; 4797268 N; 33 T; rel. 11: 20/09/2019, Belforte del Chienti (MC), 356709 E; 4779328 N; 33 T; rel. 12: 12/10/2021, Marina di Massignano (AP), 405974 E; 4768016 N; 33 T; rel. 13: 10/09/2019, Matelica (MC), Loc. Piane, 337494 E; 4796349 N; 33 T; rel. 14: 24/07/2019, Osimo (AN), Loc. Padiglione, 375354 E; 4813757 N; 33 T; rel. 15: 24/09/2019, Serra de' Conti (AN), 341462 E; 4824278 N; 33 T; rel. 16: 24/07/2019, Montefano (MC), 372499 E; 4805753 N; 33 T; rel. 17: from Fanelli 2002, Tab. 36, rel. n° 1; rel. 18: 19/06/2019, Macerata (MC), 375047 E; 4796378 N; 33 T; rel. 19: 10/09/2019, Matelica (MC), Loc. Colferraio, 339474 E; 4796335 N; 33 T; rel. 20: 18/10/2018, Castelplanio (AN), Loc. Macine-Borgo Loreto, 346354 E; 4816786 N; 33 T; rel. 21: 12/10/2019, Atri (TE), Loc. Colle Petitto, 418885 E; 4711689 N; 33 T; rel. 22: 18/10/2018, Moie (AN), 350779 E; 4818011 N; 33 T; rel. 23: 12/10/2018, Atri (TE), 418328 E; 4713782 N; 33 T; rel. 24: from Fanelli 2002, Tab. 36, rel. n° 4; rel. 25: from Fanelli 2002, Tab. 36, rel. n° 3; rel. 26: from Fanelli 2002, Tab. 36, rel. n° 7; rel. 27: from Fanelli 2002, Tab. 36, rel. n° 2.

login to comment