Flora and vegetation of fallow lands invaded by the black Cherry Padus serotina (Ehrh.) Borkh. in Lower Silesia (SW Poland)

Abandoned agricultural lands, along with prolonged periods of non-cultivation, are undergoing transformations in vegetation and changes in soil physicochemical properties^1,2. The trajectory and rate of secondary succession depend on the degree of vegetation damage and the soil properties caused by previous cultivation practices³. At the same time, this complex process is influenced by many abiotic (topography, climate, soil fertility, and moisture) and biotic (parent material and soil seed bank) factors⁴. In Central Europe, the initial phase of secondary succession of fallow land is dominated by annual weed species (e.g., Apera spica–venti, Echinochloa crus–galli), which are then replaced by perennial weeds (e.g., Elymus repens) and encroaching ruderal species (e.g., Artemisia vulgaris, Convolvulus arvensis, and Solidago canadensis)^5,6. Colonisation by woody vegetation is a long-term phenomenon that lasts from 140 to 290 years⁷ and indicates the final stage of fallow land transformation⁸. In Poland, pioneering tree species encroaching on former agricultural land include Betula pendula, Populus tremula, Pinus sylvestris, and Alnus glutinosa. They play an important role because by shading the area, they create favourable conditions for the development of shade-loving forest-forming tree species, including Tilia cordata, Carpinus betulus, and Fraxinus excelsior⁹. The development of tree formations on fallow lands has been initiated, in addition to native, light-seeded, and wind-seeded species, as well as by alien invasive species^10,11. Regardless of the stage of secondary succession, their presence often contributes to the disturbance of plant communities, the functioning of which is more complex and dynamic than that in natural ecosystems^12,13.

One of the most widespread invasive tree species in Europe, including Poland, is black cherry Padus serotina (Ehrh.) Borkh., which is native to North America^14,15. This deciduous tree exhibits considerable morphological variation across their range. In its native land, the eastern part of the USA, it can reach heights of up to 38 m with trunk diameters exceeding 1.2 m, whereas southwestern varieties and introduced European populations are significantly smaller, often remaining shrubby forms or low tress¹⁶. Padus serotina is characterised by a dark brown bark marked with numerous white lenticels and a distinctive almond-like scent. Its simple leaves are glossy, serrated, and oval to lanceolate. Black cherry blooms in late May and June, producing small white flowers arranged in loose racemes, followed by black drupes that ripen in late summer¹⁷ This species was deliberately introduced to European temperate forests, initially to obtain good-quality timber, and when it failed, as a biocenotic additive in poorly fertile habitats in the understory of Scots pine forests^17,18. In Poland, the main period of planting P. serotina in forests occurred during the 1970s and the 1980s¹⁵. Several decades later, the invasive nature of this species became apparent¹⁹. Many ecological traits of P. serotina facilitate its invasion. These include: high resistance to unfavorable environmental conditions, high potential for generative and vegetative reproduction, seed dispersal by birds and mammals, the formation of long-lived seedling banks, allelopathic interactions, and a small number of natural enemies in the initial phase of invasion^{17,20,21,22,23,24}. Currently, in disturbed forest phytocoenoses, the dense understory of P. serotina, together with the leaf litter layer of this species, strongly shades the forest floor^18,25. This results in a reduction in the cover area and the number of common, light-loving plant species in the herb and moss layer^17,26,27,28. The decomposition of black cherry litter contributes to the enrichment of the organic soil level with phosphorus and nitrogen^29,30, and changes in the soil macronutrient content initiate vegetation transformations. Species with lower nutritional requirements withdraw, whereas plants from fertile habitats simultaneously encroach^31,32,33.

Black cherry spread in forests around seed sources, fill available habitats, and then begin to colonise open areas, including abandoned farmlands^34,35,36. The scope and effects of P. serotina colonisation of fallows remains to be determined. One of the first published studies on this topic indicates that the presence of P. serotina on fallow lands can significantly alter soil properties³⁷. Knowledge of vegetation changes in abandoned agricultural lands is crucial for developing management strategies for such areas⁴. Active regeneration processes should direct succession towards a vegetation structure that enhances ecosystem services and/or livestock production (for example, through species adapted to grazing).

This paper is a continuation of our previous work³⁷ and concerns the effect of P. serotina on fallow vegetation. The aim of this study was to assess the relationship between the occurrence of P. serotina and variations in floristic composition, vegetation, and species diversity of selected fallow lands. As the main focus of this study, we used the area covered by individual plant species and species richness. We based our research on the results obtained from the study plots, both invaded and uninvaded by black cherry. In this study, we tested the following hypotheses:

• dispersal of Padus serotina in fallows triggers changes in secondary succession process,

• development of P. serotina shrubs and trees affects the plant species composition,

• in fallow lands invided by P. serotina significant changes in vegetation diversity occur.

Study area

This research was conducted on fallow lands in Lower Silesia, a region located in southwestern Poland. The selected area is characterised by significant farm fragmentation, with fallow land constituting a significant part of the agricultural landscape. Lower Silesia is characterised by a temperate climate, influenced by its inland location and proximity to the Sudetes Mountains. Summers are long and warm (average 18 °C in July), while winters are short and mild (average − 1.4 °C in January). The average annual air temperature is 8 °C. The annual precipitation in the study area ranges from 500 to 600 mm, with an average of approximately 350 mm during the growing season. The growing season lasts 220 days, making it the longest in the country³⁸.

We selected 10 fallow lands (study sites) representing plant communities of approximately 2.000 m², containing self-seeded, now mature (flowering) Padus serotina trees. The main sources of black cherry propagules in the analyzed fallow lands were forests, field woodlots, or nearby home gardens. These phytocenoses have been following a natural succession path without external interference for the past 10 years. The chosen study sites represent a variety of soil types (podzols, phaeozems, cambisols, fluvisols). The description of selected fallow lands is provided in the Fig. 1; Table 1 (for more detailes see³⁷ ).

Data collection

A total of 10 study plots (10 × 10 m squares) were designated on each of the selected fallow lands, of which five were invaded by black cherry and five were free of this species. The study plots were randomly placed within homogeneous patches of vegetation, free from areas disturbed by animal activity. The distance between the edges of the squares was not less than 10 m. This rule was also applied to the locations of the study plots in relation to the boundaries of the fallow lands, defined by dirt roads, ditches, or woodlots. Determining such a margin allowed the elimination of the edge-effect interactions on the analysed vegetation patches.

Observations were conducted in 2017 during the period of the richest vegetation (June–July). Botanical composition and the area occupied by individual plant species (species cover express in %) with species abundance were determined using the Braun-Blanquet procedure. To avoid varying interpretations of vegetation cover, observations were conducted by the same person, who visually estimated the percentage cover (5% estimate intervals) of each plant species in the study plots. The total vegetation cover was determined for three layers: the tree layer (> 1.5 m; marked with the symbol a), the shrub layer (0.5–1.5 m; b), and the lowest, ground-level layer of plants (< 0.5 m) including herbaceous plants, tree and shrub seedlings (c), and leafy bryophytes (d). A total of 100 vegetation surveys (relevé) were obtained from the study plots, creating a database used for further analysis. We determined the taxonomic affiliation of vascular plants directly in the field. Individual bryophytes were collected for laboratory identification by bryologist Ewa Fudali, PhD (Department of Botany and Plant Ecology, Wrocław University of Environmental and Life Sciences, Poland). The identified moss material is in the private collection of Aleksandra Halarewicz. No species protected in Poland were found in the analysed flora. Vascular plant nomenclature follows Mirek et al. ³⁹, and moss species names are based on Ochyra et al.⁴⁰. The Latin species name Padus serotina (Ehrh.) Borkh., is consistent with the publication of flowering plants and pteridophytes of Poland, a checklist³⁹, and is the equivalent of Prunus serotina Ehrh., the species name of the black cherry used in Flora Europea⁴¹. The plant communities were identified according to the method described by Matuszkiewicz⁴².

Data analysis

Principal component analysis (PCA) with rotation using non-metric multidimensional scaling (NMDS)⁴³ was used to assess the diversity of plant species in the selected fallows. Analyses were conducted using a floristic database of 100 study plots, representing the area occupied by individual plant species. Species occurring simultaneously in multiple layers within the same study plot were analysed separately for each layer. In the analyses, the distances between samples were estimated using Euclidean distance. The stress value was used to assess the model quality.

To reveal the main environmental gradients for the variation in the herb layers, a detrended correspondence analysis (DCA) was conducted⁴⁴. All ordination analyses were performed without data transformation. The length of the gradient, represented by the first ordination axis, had a standard deviation of four units, which indicated the unimodal nature of the floristic database and recommended the choice of a specific direct ordination technique. Based on this, we decided to use canonical correspondence analysis CCA⁴⁴ for further analyses. This allowed us to assess the influence of habitat variables (represented by the cover of Padus serotina separately in three vegetation layers) on the floristic composition of the study plots. The significance of the variables was tested using the Monte Carlo permutation test with stepwise variable selection⁴⁵. The influence of individual habitat variables on species composition (marginal effects) as well as their combined influence (conditional effects) was tested.

Additionally, to illustrate the relationships between black cherry in the tree and herb layers (significant habitat variables) and individual plant species in the database, a generalised additive model (GAM) was used⁴⁶. The GAM plots included only the species selected after analysing the mean cover and frequency values. These taxa had an average cover of above 5% and occurred in at least 10% of the study plots. All ordination analyses were performed using the CANOCO v. 5.03 software.

The impact of black cherry on fallow vegetation diversity was assessed based on species richness and diversity indices, which were calculated separately for the study plots invaded by black cherry and those free of this species. The Shannon diversity index was calculated as follows: (:{H}^{{prime:}}=sum:_{i=1}^{s}(pi:times:text{ln}pi)), and the evenness index was calculated as: (:J{prime:}=frac{H{prime:}}{lnS::}), where (:pi=:frac{ni}{N}), ni is the abundance of the ith species expressed as its cover, N is the sum of abundances of all species, and S is the total species richness. The value of each diversity parameter was calculated for all the layers considered together. In the next stage of the study, we focused on the relationship between P. serotina, present in the three vegetation layers, and diversity parameters determined for the herb and moss layers. The vertical structure of the vegetation was not well developed in all 100 study plots; the presence of a tree layer (excluding P. serotina) was found in six study plots, and the shrub layer in four (Table S1 (Supplementary)). Therefore, we decided to refer only to the vegetation layers present in all the plots. The MVSP v. The 3.131 package⁴⁷ was used to calculate all diversity parameters. The normal distribution of variables was evaluated using the Shapiro–Wilk test. Levene’s test was used to check for the homogeneity of variance. The parametric Student’s t-test was used to determine the significance of differences between the parameters. Correlations between the analysed parameters were examined using Pearson’s rank correlation. The strengths of the correlations were interpreted according to Stanisz⁴⁸. Calculations were performed at a significance level of p ≤ 0.05, for the entire database. The above analyses were conducted using the STATISTICA v. 13⁴⁹ software.

Directions of vegetation changes in the studied fallow lands

A total of 191 plant species were recorded across all the study plots (Table S1 (Supplementary), Table 2). They form floristically impoverished communities, in particular, devoid of species that are characteristic of lower syntaxa. Most of the identified species represent semi-natural and anthropogenic meadow communities of the class Molinio-Arrhenatheretea and communities of perennial plants in ruderal areas of the class Artemisietea vulgaris.

The analysed fallow lands are similar in terms of the succession processes occurring within them. The main type of transformation is the encroachment of invasive and expansive native species, particularly Solidago gigantea and Calamagrostis epigejos. Well-developed patches of the Rudbeckio-Solidaginetum association, dominated by S. gigantea, were found throughout the study plots of F5, F6, F7, F9, F10, and F2 plots without P. serotina. Patches of the Calamagrostietum epigeji association were also clearly visible, either as independent patches of herbaceous vegetation or mosaic with S. gigantea. Well-developed patches of this association were found in both F8 and F1 plots without black cherry. Less developed patches, co-occurring with patches of the Rudbeckio-Solidaginetum association, were found within the entire F9 fallow and in F5 plots without P. serotina.

The remaining fallow lands are dominated by meadow vegetation (class Molinio-Arrhenatheretea, especially the order Arrhenatheretalia elatioris), shrubland (subclass Galio-Urticenea and class Epilobietea angustifolii), and ruderal vegetation (subclass Artemisienea vulgaris and class Agropyretea intermedio-repentis). Relatively well-developed patches of meadow communities, characterised by fresh meadow characteristics but with a clear tendency to desiccation, were found throughout the F3 fallow. In the remaining fallows, the presence of truncated meadow-ruderal or meadow-shrub communities was observed, mostly with a tendency for desiccation (suggested by the presence of Artemisia campestris, Euphorbia cyparissias, Hieracium pilosella).

Another direction of change is the gradual succession of the woody species. This is particularly visible in the F9 fallow, where seedlings and saplings of Syringa vulgaris form a mosaic with other woody species, C. epigejos, and the dominant S. gigantea. In turn, on fallow F4 (study plots with P. serotina), as well as F7 and F9 (all study plots), large numbers of Rubus caesius were recorded. The initial stages of woody species succession, with the encroachment of representatives of Rhamno-Prunetea, Querco-Fagetea, and other tree and shrub species, were observed in fallow F1 and F3 (only in plots with P. serotina) and in both types of study plots of all the remaining fallows.

The least visible trend was the appearance of segetal species, primarily in areas with disturbed soil cover, which generally disappeared from the studied post-agricultural fields. Vicia hirsuta and Viola arvensis were found on most of the studied fallow lands, often occurring with considerable phytosociological stability (even V), but at marginal cover abundance.

Analysis of the impact of Padus serotina on plant species composition

Comparisons of plant species composition with their quantity expressed in percentage scale, which were made on 50 study plots invaded by Padus serotina and 50 without the presence of this species, were subjected to PCA analysis with rotation using the NMDS method. In the analyses, the distance between the samples was estimated using the Euclidean distance with the three-dimensional final solution obtained from 42 interactions. The stress value of the resulting model was 14.86%, indicating a good quality. The eigenvalues for the first two canonical axes were 0.4308 and 0.3001, explaining 43% and 30% of the total variation in the vegetation data, respectively. The diagrams present the location of the study plots within the fallows (Fig. 2) and the arrangement of all plant species, considering their belonging to the plant layer (Fig. 3). In the ordination space created by the first two axes, the separation of the study plots along the first and second canonical axes was clearly visible (Fig. 2). The study plots not inhabited by P. serotina were located on the left side of the ordination space, and those where P. serotina was present were on the right. The exception is study plot 51, dominated by giant goldenrod, the only plot where black cherry is absent from the shrub layer but occurs in the tree and herb layers (Table S1 (Supplementary)). The disturbance in species composition caused by the presence of Solidago gigantea and Calamagrostis epigejos is shown in Fig. 3. The above species are located at the extreme left of the first ordination axis, whereas P. serotina occupies the farthest position on the right of the same axis. Along the second canonical axis, a separate position in the ordination space was occupied by P. serotina in the shrub layer and, on the opposite side of the axis, by the nitrophilic species Arrhenatherum elatius and Tanacetum vulgare.

CCA analyses allowed for the identification of general relationships between plant species in the ground-level layer and environmental variables, represented by P. serotina cover in the herb, shrub, and tree layers. Based on the calculations, the eigenvalues of the first two canonical axes were found to be 0.265 (first axis) and 0.186 (second axis), respectively. These axes explained 3.3% and 2.3% of the total variation in plant species composition, and 49.4% and 34.7% of the variation in the relationships between species and the presence of P. serotina, respectively. The results of the stepwise selection of variables using the Monte Carlo permutation test showed a significant relationship between the presence of black cherry and the species composition of herbaceous plants, tree and shrub seedlings, and leafy bryophytes (Table 3). Analysing the influence of variables acting together, the strongest relationship was found between species composition and P. serotina in the shrub layer and a slightly weaker relationship between species composition and P. serotina in the tree layer. The ordination diagram using the first two canonical axes shows the distribution of species and environmental variable vectors (Fig. 4). The black cherry vector in the tree layer was weakly and positively correlated with the second canonical axis, whereas the vector illustrating P. serotina in the herb layer exhibited a slightly stronger correlation with the first axis. The absence of species near the ends of the environmental variable vectors indicated a lack of positive relationships with these variables. Note the abundant species occurring in opposite positions, extending the beginning of the vectors of the analysed habitat variables. Their location indicated a negative relationship with the area covered by P. serotina in the tree and herb layers.

To more precisely examine the relationships between the occurrence of black cherry in the herb and tree layers and between specific species in the herb and moss layers, generalised additive models (GAMs) were used (Fig. 5). Three species exhibited a clear response to an increase in cover by P. serotina in the tree layer. The curve for Solidago gigantea was the most dynamic, demonstrating both a reduction in the cover by approximately 20% (with an increase in the cover by P. serotina in the tree layer to 40%) and an increase of approximately 15% (with a canopy closure of P. serotina ranging from 40% to 80%). The curve for Calamagrostis epigejos provides information on the decrease in the area occupied by this species, from approximately 13% to less than 5%. In the case of the grass Arrhenatherum elatius, an approximately 10% increase in cover was observed in response to canopy closure of P. serotina ranging from 60 to 100%. The strongest response to P. serotina cover in the herb layer was observed in S. gigantea. Coverage by this species decreased from approximately 22% to zero with increasing seedling and P. serotina sapling density. Similarly, the curve for C. epigejos showed an overall decline in species cover from approximately 14%.

The impact of Padus serotina on the species diversity of fallows vegetation

The analysis of diversity parameters indices for the study plots inhabited by black cherry and those free of this species revealed significant differences. Higher values of the diversity index (H’) were observed (t = 4.215; p ≤ 0.0001). Shannon-Wiener evenness index (J′) (t = 3.496; p = 0.001) and species richness (s) (t = 3.956; p ≤ 0.0001) were observed in the plots invaded by Padus serotina. Additional information on the relationship between P. serotina considering its proportion in the individual vegetation layers and the parameters describing the diversity of the herb and moss layers were considered together. is provided by correlation analyses (Table 4) and figures prepared for statistically significant correlations (Fig. 6).

Based on these data, a weak correlation was found between the occurrence of P. serotina shrubs and the value of the diversity index (H’) for vegetation in the herb and moss layers. A stronger effect was associated with the presence of black cherry in the herb layer and the value of each of the analysed diversity parameters (H′, J′, and s).

The presence of Padus serotina in Europe dates back to almost four centuries. The intensive spread of this species, particularly over the last few decades, has influenced the floristic composition, spatial structure, dynamics, and stability of colonised phytocoenoses, particularly in forests^18,26,29. Our floristic studies confirmed that P. serotina can also play a significant role in the early stages of secondary succession in abandoned agricultural lands. In most of the study plots, P. serotina was observed to have a well-developed shrub layer and abundant seedlings and saplings in the herb layer. New populations of black cherry are expanding, occupying areas immediately adjacent to previously colonised sites. A long-lived seed bank, deposited annually near parent plants²⁰, and the ability to spontaneously produce root suckers⁵⁰ result in a rapid increase in the density of juveniles^34,36. Fruits are eaten willingly and dispersed by birds⁵¹. Birds carry fruit up to approximately 100 m from the parent plant³⁶. Without bird involvement, most fruits fall no further than 5–10 m from the seed source⁵². Under favourable conditions, colonisation of fallow lands can proceed so rapidly that a period of less than 10 years is sufficient to form a dense layer of P. serotina shrubs growing up to 2 m in height¹¹. At the same time, new foci of species invasion in already colonised areas have been assessed by scientists as sporadic^36,51.

The fallow lands we selected were dominated by meadows, shrublands, and ruderal vegetation. Fallow flora did not form clear patterns associated with the presence or absence of P. serotina. Because of the relatively short time that has passed since the abandonment of cultivation in fields, the soil seed bank of segetal species, especially from the class Stellarietea mediae, should still be rich and shallow. However, the proportion of weed species from the segetal communities in the fallow flora was low. This may be due to the strong competition and possible allelopathic effects of other species, but also to the lack of cyclical disturbances in the topsoil. The actual vegetation of fallows does not always reflect the species present in the soil seed bank⁵³. The presence of representatives of classes such as Phragmitetea, Koelerio-Corynephoretea, and Festuco-Brometea within the studied fallows appeared to be accidental. According to previous research, plant communities developing on fallow lands constitute heterogeneous groups and are usually dominated by one or several expansive plant species that reproduce mainly vegetatively (for example: Agrostis capillaris, Holcus mollis, Elymus repens)⁵⁴.

Fallow fields are among the most disturbed phytocoenoses, which further promotes the encroachment and establishment of alien species, including invasive ones⁵⁵. Our observations confirm the colonisation of fallow lands by invasive species, especially Solidago gigantea. The average cover of S. gigantea in the study plots with and without P. serotina was comparable. However, the response patterns of S. gigantea to an increase in P. serotina cover are not clear. The effect of black cherry, illustrated by GAM, was both limited (realised by the youngest developmental stages of P. serotina, probably through competition for resources and allelopathy) and stimulating (concerning P. serotina trees, which, with a crown closure of 40–80%, create a favourable microclimate and provide nutrient-rich litter). Studies by other authors have indicated that the varied response of S. gigantea may also result from the ecological properties of the species itself, which are less competitive and grow slower in drier locations⁵⁶. Invasive species of the genus Solidago often dominate fallows and form dense stands^57,58. Such degenerated plant communities are also invaded by the native expansive species Calamagrostis epigejos^58,59. In the fallow lands examined, the occurrence of C. epigejos was also observed, and the presence of P. serotina in vegetation patches contributed to the decline of this species.

This contradicts the results of our study, in which P. serotina was not the dominant species in the fallows. In the fallow lands we selected, the average cover by P. serotina shrubs did not exceed 46%, whereas in the cited study by Hejda et al.⁶⁰ the cover by S. gigantea was 70–100%, for H. mantegazzianum 90–100%, and for R. japonica 100%. The impacts of invasive species worsen as the invasion process continues, and the cover of the alien species increases¹². An increase in the density and spread of the P. serotina population is a continuous process that results in a continuum of changes in plant community structure. Furthermore, the invasion of herbaceous species modifies the course of secondary succession in fallows in contrast to the invasion of non-native trees. Black cherry participates in the formation of mid-field shelterbelts, which favour bird migration and propagule dispersal, helping to maintain a high level of biodiversity in agricultural areas⁶¹. According to Benton et al.⁶², the presence of non-native woody plants is more beneficial for local species richness than the complete absence of such landscape elements in agrophytocenoses.

Scientific studies lack information on the impact of P. serotina on plant biodiversity in synanthropic habitats. In open communities (meadows, wastelands, roadsides), invasive herbaceous species such as Reynoutria spp., Heracleum mantegazzianum, Solidago spp., and Rudbeckia laciniata contribute to a decline in species richness in inhabited vegetation patches^60,63. Our results indicate that P. serotina has a positive impact on the diversity of fallow vegetation. It should be emphasised that we analysed the vegetation condition at the initial phase of secondary succession, and black cherry was not yet the dominant species in the fallows. The cover by P. serotina shrubs did not exceed 46%, whereas in the cited study by Hejda et al. ⁶⁰ the cover by S. gigantea was 70–100%, for H. mantegazzianum 90–100%, and for R. japonica 100%.

The invasive species’ impacts worsen as the invasion process continues and the cover of the alien species increases¹². Because the increase in the density and spread of P. serotina populations is a continuous process, further changes in the plant community structure can be expected. Furthermore, the invasion of herbaceous species modifies the course of secondary succession on fallows in contrast to the invasion of alien trees. Black cherry participates in the formation of mid-field shelterbelts, which favor bird migration and propagule dispersal, helping to maintain a high level of biodiversity in agricultural areas⁶¹. According to Benton et al.⁶², the presence of non-native woody plants is more beneficial for local species richness than the complete absence of such landscape elements in agrophytocenoses.

The high level of species diversity observed in the plots with P. serotina in our study may also be related to their greater fertility following the decomposition of black cherry litter compared to the plots not inhabited by the studied species. Fallow sites are generally relatively fertile habitats⁶⁴, where an increase in the number of flora species was first observed during the process of directional environmental changes^59,65. These originate from the rich seed bank, as well as the introduction of propagules of other species⁶⁶. According to Hochół et al.⁶⁷ the floristic richness of segetal communities is associated with a large number of species with a low degree of cover. This may be true for species whose presence is entirely accidental and/or related to deliberate human activity (dumping garden waste), such as Iris sibirica and Fragaria × ananasa, found in our study on black cherry thickets. The presented results allowed us to identify temporary relationships accompanying secondary succession in selected agrophytocenoses, justifying the need for further research in this area.

The influence of Padus serotina on fallow vegetation represents a complex long-term ecological process. Our study demonstrated that seedlings and saplings of this species have the strongest impact on the species composition of fallow lands. As P. serotina cover increases in the herb layer, expansive species such as Calamagrostis epigejos and Solidago gigantea decline, allowing for the development of more diverse plant communities. Additionally, black cherry forms low thickets that provide perching sites for birds, promoting seed dispersal and the development of multispecies shrubs. Our results indicated a positive effect of P. serotina on species diversity in the early to mid-stages of secondary succession. To the best of our knowledge, this is the first study to assess the impact of P. serotina on perennial fallow lands, making it an important reference point for the future. The impact of the analysed species on vegetation composition and biodiversity may change as succession progresses. Therefore, further long-term monitoring is necessary to fully assess how this invasive species influences secondary succession dynamics and biodiversity in fallow lands, thereby providing a basis for future management and conservation strategies.