Analysis of Associated Woody and Semi-Woody Local Wild Species in Entre Ríos, Argentina: Exploring the Agricultural Potential of Hexachlamys edulis

Abstract

The loss of native forests in Argentina has been a concern, driven by factors such as agriculture expansion and urbanization. Therefore, understanding the conservation status of sampled populations and their adaptation to different plant communities is essential. This research focused on the heterogeneity analysis of the associated woody and semi-woody vegetation to Hexachlamys edulis (O. Berg) Kausel and D. Legrand, a species commonly known as “ubajay” in Entre Ríos, Argentina. The study aimed to record the species present in the populations, explore plant communities associated with H. edulis, identify other potentially useful agroforestry species, compare locations based on the similarity of accompanying species, and explain the conservation status of each population. Results revealed a total of 71 species belonging to 39 families. The Myrtaceae family was the most relevant, particularly in terms of native species representation. The analysis of biodiversity indicators, including richness, the Shannon index, and dominance revealed variations among the studied sites. The anthropic indicator highlighted the impact of human activity, with Concordia showing a higher ratio of native-to-exotic species. Cluster analysis and ordination techniques revealed groupings of censuses from the same localities, indicating differences in vegetation composition between sites. Significant differences in species composition were found among the sampled populations. Overall, the study can serve as baseline information for future research on the dynamics of vegetation in these areas and on the studied H. edulis species. Finally, these findings contribute to understanding how wild species like H. edulis adapt to different plant communities, which might be valuable for developing new agroecological approaches or identifying potential companion planting species in future agricultural systems.

1. Introduction

Native forests and biodiversity play a pivotal role in ecological, economic, and social sustainability. From an environmental perspective, they act as carbon sinks, helping to reduce the amount of carbon dioxide in the atmosphere. They protect the soil from erosion and maintain the water quality of wetlands and rivers. Also, native forests provide valuable ecosystem services [1]. These services include hosting insect pollinators, purifying the air, mitigating the effects of floods, storms, and noise pollution [2], and stabilizing dunes in desert areas [3], among others. Indeed, links have been demonstrated between biodiversity and improvements in objective measures of health and well-being [4]. Even today, many Indigenous Peoples and Local Communities rely on native forests as a source of food and medicine in addition to their cultural value [5].

The ecological stability of native forests depends on biodiversity; therefore, they are essential for maintaining a healthy and balanced ecosystem, and their conservation is crucial to ensure the availability of resources and services for future generations. In this regard, it is necessary to take measures to protect and conserve them. This can be achieved through the creation of protected areas, the implementation of sustainable agricultural and livestock practices, and the promotion of environmental education and awareness among the population. Without immediate action, these areas and their biodiversity are at risk of degradation or even permanent loss, as they harbor endemic organisms that are at risk of extinction. Success or failure will depend on international cooperation efforts such as the Kunming-Montreal Global Biodiversity Framework [6] and the Forests, Trees, and Agroforestry Partnership [7], as well as the actions of each and every one of us.

Local wild species are essential for informing sustainable management practices and developing innovative, resilient, and sustainable agricultural systems, thus contributing to the well-being of communities and the conservation of our natural heritage. Integrating knowledge of biodiversity into forest management strategies allows for the design of practices that conserve and enhance these ecosystems. For example, identifying and protecting key plants and animals can foster the natural regeneration of the forest and long-term sustainability. Additionally, research on ecological interactions and biological processes and the detection of key indicators provides crucial information for the restoration of degraded areas, the creation of biological corridors that connect fragmented habitats, and the incorporation of new species into cropping systems [8].

Despite their importance, the area of native forests in Argentina has suffered a loss of 6,631,000 hectares between the years 1990 and 2020. In 2020, an estimated 27,137,000 hectares of native forests were recorded, which represents 10.28% of the country’s total land area [9]. The main causes of deforestation are attributed to the expansion of agriculture, livestock farming, and urbanization [10,11]. In particular, this fact coincides with the global trend of a dramatic acceleration in cropland expansion within protected areas from 2000 to 2019 [12]. In general, these advances in conserved areas and human activity result in biodiversity loss and the introduction of exotic species. Identifying the introduced taxa and understanding how native species adapt to human environments provides valuable insights into ecosystem functioning, invasion patterns, and resilience. This highlights the importance of assessing the environmental quality of all species, especially non-native ones, to fully understand how ecosystems are impacted by human activity. However, despite this situation, there are still areas with low anthropogenic impact, as is the case with the riparian forest along the Uruguay River in the province of Entre Ríos. These areas are crucial for biodiversity due to the vegetation intrusion phenomenon, in which species from the Paranaense Province migrate southward through the Uruguay and Paraná Rivers and adapt to the riparian microclimate [13,14]. In fact, this situation results in an increase in heterogeneity and diversity within and between species and ecosystems, respectively. Mass effect, the occurrence of species outside their core habitats, could also be explained by this phenomenon [15].

A species that stands out in these areas is Hexachlamys edulis (O. Berg) Kausel and D. Legrand, commonly known as “ubajay.” This species is found in areas near watercourses and riparian forests along the Paraná and Uruguay Rivers. Furthermore, it is notable for its edible fruit and its potential as a non-timber forest resource of importance for health and nutrition. Without a doubt, H. edulis stands out as a promising species for incorporation into cropping systems to enhance biodiversity and promote sustainable agricultural practices [16,17,18,19,20].

Within the framework of studies on the phenotypic variability of H. edulis, which is necessary for subsequent breeding and domestication efforts, it is essential to understand the conservation status of the sampled populations. This understanding can help assess the potential risks faced by this species and determine whether H. edulis populations coexist with different woody and semi-woody plant communities. According to Llorente–Culebras et al. [21], woody plants were the most frequently studied group in global biodiversity research on protected areas, and these communities support numerous other species while significantly contributing to local biodiversity [22].

H. edulis exhibits remarkable adaptability to the riparian ecosystems of the Paraná and Uruguay Rivers, where its nutritional value of the edible fruit position it as a promising candidate for agroforestry systems. By integrating H. edulis into cropping systems, we can enhance biodiversity, promote soil health, and provide a sustainable source of non-timber forest products. Its presence within diverse plant communities opens avenues to investigate ecological interactions with both native and exotic species, thereby enriching our understanding of local biodiversity dynamics. This study aims to evaluate the conservation status and agroforestry potential of H. edulis within these ecosystems, filling a significant research gap, as few studies in the region have addressed this, with the exception of the study in NP El Palmar [23].

The objectives of this study are fivefold: (1) to document the species and families present in the habitats where H. edulis grows, focusing on other species with potential agroforestry applications; (2) to analyze biodiversity indicators within the woody and semi-woody communities associated with H. edulis; (3) to assess the conservation status of each population based on the ratio of native-to-exotic species; (4) to compare different locations by examining the similarity of woody and semi-woody species accompanying H. edulis trees, specifically exploring species richness to determine the occurrence of H. edulis across various plant communities; and (5) to recommend other outstanding species in the populations under study for introduction into agroforestry systems.

2. Materials and Methods

2.1. Plant Material and Studied Populations

In September 2019, a total of 40 adult trees of H. edulis with a diameter at breast height greater than 7.5 cm were randomly selected from three populations in the riparian forest along the Uruguay River in Entre Ríos (Figure 1), ensuring that they were spaced more than 5 m apart and not dead. The labeled individuals ranged from 154 to 208 in Concordia, from 260 to 288 in National Park (NP) El Palmar, and from 305 to 364 in Gualeguaychú, covering an approximate area of 300 km². Specifically, 12 individuals were selected in Concordia (76 hectares, −31.28590 S: −57.96305 W; IUCN category not reported), 15 in NP El Palmar (150 hectares, −31.86395 S: −58.20998 W; IUCN category II), and 13 in the private reserve El Potrero de San Lorenzo in Gualeguaychú (16 hectares, −33.06490 S: −58.26965 W; IUCN category VI) [24]. A radius of 3 m around each selected H. edulis tree was established to record and count accompanying woody and semi-woody perennial species, ensuring a minimum surveyed area of 28.3 m², followed by the taxonomic classification and documentation of all species present.

These sites had experienced varying degrees of human disturbance, including agriculture and urban development. Furthermore, the study site in Concordia is surrounded by recreational activities, including camping, local fishing visitors, and small productive establishments, which may contribute to varying degrees of human disturbance. However, NP El Palmar is comparatively more conserved, although it experiences some level of anthropization due to tourism and camping activities. Lastly, in Gualeguaychú, the area is relatively well-preserved, as it is not publicly accessible; however, there are nearby forestry and beekeeping productions that may influence the local ecosystem dynamics.

2.2. Climate Characterization

The recorded monthly average temperatures and precipitation for each study site between 1991 and 2021 are shown in Figure 2 and Figure 3 [25]. Temperature and precipitation patterns provide valuable insights into the climatic conditions that influence the growth and distribution of H. edulis and other plant species in the area.

2.3. Biodiversity Indicators and Statistical Analysis

In addition to species richness as a primary measure of biodiversity [26] and to address the complexity present in the structure of a plant community, various indicators were employed, such as dominance, equitability, and evenness (

Table 1. Formulas and breakdown of biodiversity and anthropic indicators used in the study. The table outlines various indicators, including Shannon entropy, dominance, equitability, evenness, Margalef’s index, and an anthropic indicator, along with their respective formulas and detailed breakdowns.

Indicator	Formula	Formula Breakdown
Shannon	H = −Σ(pi*log(pi))	Calculate the sum of the product of each species’ abundance proportion (pi) and its logarithm.
Dominance	D = Σ(pi^2)	Sum the squared proportions of each species’ abundance.
Equitability	J = H/log(S)	Divide the Shannon entropy (H) by the logarithm of the number of species (S).
Evenness	e^H/S = exp(H)/S	Calculate the exponential of Shannon entropy (H) divided by the number of species (S).
Margalef	M = (S − 1)/log(N)	Subtract 1 from the number of species (S) and divide it by the logarithm of the total individuals (N).
Anthropic Indicator	Ia = (n° natives)/(n° natives + n° exotics)	Divide the number of native species by the sum of native and exotic species counts.

).

First, vegetal community structure was characterized by calculating species abundance and species richness. The Shannon–Wiener index [27] of species diversity (H’), dominance (D), Pielou equitability (J), evenness (e^H/S), and Margalef index (M) were also calculated at each site according to formulas in Table 1 using PAST 3.24 [28]. A distinction was made between native and exotic species, and an anthropic indicator (Ia) was generated (adapted from Nápoles) [29] to indicate the ratio of native-to-exotic species, where 1 indicates completely native vegetation and 0 indicates completely exotic vegetation. Prior to statistical analyses, normality, and homogeneity of variances were assessed for the calculated dependent variables using the Shapiro–Wilks and Levene tests. For each index, an analysis of variance was conducted comparing the three study sites. General linear models were used, either with variance adjustment by site or generalized linear models using a gamma distribution with an identity link function as appropriate. Multiple comparison analyses were performed using the Tukey test (p-value = 0.05).

Furthermore, to measure differences in species structure among the studied locations and to compare the heterogeneity of the accompanying vegetation, a presence absence matrix was created. First, species with occurrences of lower than 7.5% were removed. The data were standardized through normalization, and then, the dissimilarity matrix was calculated based on the Bray–Curtis index. Complementary clustering methods, such as Ward’s merging algorithm for cluster analysis, which delivers mutually exclusive groups where each group includes members with the highest similarity, providing maximum internal homogeneity [30].

To conduct the Principal Coordinates Analysis (PCoA), we constructed a similarity matrix based on the abundance of species across different censuses using the Bray-Curtis index, which is particularly suitable for presence–absence and abundance data, as noted by Palacio et al. [31]. This method allows for the ordering of sampling units according to a measure of similarity that reflects the relationships within the data without imposing the limitations of Principal Component Analysis. In the analysis, three dimensions (k = 3) were determined to adequately represent the variability present in the data. The significance of the principal coordinates was expressed as a percentage of the total variance explained, enabling the interpretation of results based on the distribution of samples. The PCoA results were visualized using scatter plots, where each point represents a sampling unit, differentiated by population. Additionally, ellipses were included to visualize variability, and labels were used to identify the censuses, facilitating the interpretation of the observed patterns in species distribution across different sites.

Discriminant analysis was also performed, with Mahalanobis distances, to classify groups based on selected ecological variables and to maximize the differences between these groups. This analysis employed a canonical discriminant approach, allowing for the identification of the linear combinations of predictor variables that best separate the predefined groups. The significance was evaluated using multi-response permutation procedures (MRPPs) with 1000 permutations and the Bray–Curtis distance method. All data were analyzed using Rstudio [32].

3. Results

3.1. Biodiversity Indicators

The total flora of the studied areas was cataloged, revealing 39 families with a richness of 71 species and an abundance of 613 individuals (

Table A1. Presence (P) and absence (A) of native and exotic species and abundance in Concordia, NP El Palmar, and Gualeguaychú. The complementary figure below shows the species found at each site and their abundance.

Family	Species	Concordia	NP El Palmar	Gualeguaychú
Native
FABACEAE	Acacia caven	P	P	P
SAPINDACEAE	Allophylus edulis	P	P	P
LILIACEAE	Asparagus setaceus	A	A	P
FABACEAE	Bauhinia forficata	A	A	P
MYRTACEAE	Blepharocalyx salicifolius	P	P	A
LOGANIACEAE	Buddleja globosa	A	A	P
ARECACEAE	Butia yatay	P	P	A
ULMACEAE	Celtis iguanaea	A	A	P
ULMACEAE	Celtis tala	P	P	P
RUBIACEAE	Cephalanthus glabrotus	P	A	A
SOLANACEAE	Cestrum parqui	A	A	P
VITACEAE	Cissus verticilata	P	A	A
RUTACEAE	Citrus aurantium	A	P	A
RANUNCULACEAE	Clematis montevidensis	P	A	A
CUCURBITACEAE	Cyclanthera hystrix	P	A	A
BIGNONIACEAE	Dolichandra cynanchoides	A	P	A
FABACEAE	Erythrina crista galli	P	A	P
MYRTACEAE	Eugenia uniflora	P	A	P
MYRTACEAE	Eugenia uruguayensis	P	P	P
ENOTERACEAE	Fuchsia magellanica	A	P	P
ASTERACEAE	Heterothalamus alienus	P	A	A
MYRTACEAE	Hexachlamys edulis	A	A	P
BIGNONIACEAE	Jacaranda mimosifolia	A	P	A
TILIACEAE	Luehea divaricata	P	A	A
BIGNONIACEAE	Magfadenia unguis cati	A	P	A
CELASTRACEAE	Maytenus ilicifolius	A	A	P
POLYPODIACEAE	Microgramma lycopodioides	A	P	A
FABACEAE	Mimosa pilulifera	P	A	A
FABACEAE	Mimosa sp.	P	A	A
POLYGONACEAE	Muehlenbeckia sagittifolia	P	A	P
MYRTACEAE	Myrrhinium atropurpureum	A	P	A
MYRSINACEAE	Myrsine laetevirens	A	A	P
MYRTACEAE	Myrtus mucronatum	P	A	A
LAURACEAE	Ocotea acutifolia	P	A	A
MALVACEAE	Pavonia malvacea	P	A	A
FABACEAE	Poecilanthe parviflora	P	A	A
SAPOTACEAE	Pouteria salicifolia	A	P	P
EUPHORBIACEAE	Sapium haematospermun	A	P	A
ANACARDIACEAE	Schinus longifolius	A	P	P
ANACARDIACEAE	Schinus molle	A	P	A
RHAMNACEAE	Scutia buxifolia	A	P	P
EUPHORBIACEAE	Sebastiania brasiliensis	P	A	P
FABACEAE	Sesbania punicea	P	A	A
SOLANACEAE	Solanum amygdalifolium	P	A	A
SOLANACEAE	Solanum jazminoides	A	P	A
SOLANACEAE	Solanum mauritianum	A	P	P
MALPIGHIACEAE	Stigmaphyllon bonarense	P	A	A
COMBRETACEAS	Terminalia australis	P	A	A
ASTERACEAE	Tessaria integrifolia	P	A	A
VERBENACEAE	Verbena littoralis	A	P	A
Exotic
VERBENACEAE	Aloysia gratissima	A	P	A
BASELLACEAE	Anredera cordifolia	P	A	A
VERBENACEAE	Citharexylum montevidense	P	A	A
ROSACEAE	Crataegus oxyacantha	A	P	A
EPHEDRACEAE	Ephedra twediana	A	P	P
MYRTACEAE	Eucalyptus grandis	P	A	A
PROTEACEAE	Grevillea robusta	A	P	A
CONVOLVULACEAE	Ipomea sp.	P	A	A
CONVOLVULACEAE	Ipomoea cairica	P	P	A
OLEACEAE	Jazminum humile	A	P	A
JUNCACEAE	Juncus acutus	P	A	P
VERBENACEAE	Lantana camara	A	A	P
OLEACEAE	Ligustrum lucidum	A	P	A
OLEACEAE	Ligustrum sinensis	A	P	A
MELIACEAE	Melia azederach	A	P	A
MALVACEAE	Pavonia hastata	P	A	A
LAURACEAE	Persea americana	A	A	P
ARECACEAE	Phoenix canariensis	P	A	A
SALICACEAE	Populus nigra	A	A	P
SALICACEAE	Salix babylonica	A	P	A
Total		35	32	26

in Appendix A). Only four species, all of them native, displayed absolute consistency and were found in the three sites: Acacia caven, Allophylus edulis, Celtis tala, and Eugenia uruguayensis. The number of native species with the highest fidelity, meaning that they only grow at each site, is six in Concordia (Clematis montevidensis, Heterothalamus alienus, Mimosa pilulifera, Myrtus mucronatum, Pavonia malvacea, and Stigmaphyllon bonarense), three in NP El Palmar (Myrrhinium atropurpureum, Schinus molle, and Solanum jazminoides), and five in Gualeguaychú (Asparagus setaceus, Buddleja globosa, Celtis iguanaea, Maytenus ilicifolius, and Myrsine laetevirens).

The individuals of the Myrtaceae family had the highest relevance, as it was the family with the greatest representation of native species in Concordia and Gualeguaychú and the second highest in NP El Palmar, following the Anacardiaceae family (Figure 4).

The most frequent native species at the sites were Eugenia uruguayensis (17), Scutia buxifolia (15), and Allophylus edulis (13), while the most frequent exotic species were Ephedra twediana (9), Asparagus setaceus (8), and Juncus acutus (6) (Figure 5).

The average number of individuals and species was significantly different between Gualeguaychú (17.38 and 6.23) and NP El Palmar (10.00 and 4.29), while Concordia did not show any differentiation (15.33 and 5.42, respectively). According to the Margalef index, there are not statistical differences between populations (Figure 6). Equitability was similar for the three populations, and the uniformity explained by evenness (e^H/S) for each site was also very similar. Dominance was significantly higher in NP El Palmar (0.36) than in Gualeguaychú (0.22), although without differences with Concordia (0.28). Also, the ecological diversity calculated using the Shannon–Weaver index shows significant differences between NP El Palmar (1.23) and Gualeguaychú (1.66). Lastly, the anthropic indicator value was 0.85 for Concordia, 0.78 for NP El Palmar, and 0.70 for Gualeguaychú.

3.2. Multivariate Analisys

Cluster analysis (Figure 7) shows a grouping of the censuses into three clusters. Each cluster is represented by the censuses from each population, except for 288, 305, 306, 321, 281, and 285. This means that 85% of the censuses are grouped within the censuses from the same population. NP El Palmar and Gualeguaychú show a lower distance explained by vegetation composition.

Consistent with the cluster analysis, the representation of the two principal coordinates in the PCoA (Figure 8) shows a clustering of censuses from the same locality, except for 288. In other words, the clustering into three main groups predominantly includes censuses from the same populations. Principal coordinates explain the 22.5 and 14.2% of the variation. Also, in the populations of NP El Palmar and Gualeguaychú, a greater dispersion is observed in the multidimensional scaling compared to Concordia, which appears to have a more homogeneous vegetation composition. The MRPP analysis of species composition changes showed significant differences among the sampled populations (delta = 0.001).

In the discriminant analysis, the maximum separation between groups and the relative location of the species represented in the discriminant canonical axes can be observed (Figure 9). The separation between groups is complete, and the apparent error rate from cross-validation was 0%. This validation implies that if some data are obtained from one of these populations without knowing which one, and we represent its position in this multidimensional space, we would correctly identify the population with a success probability of 100%.

4. Discussion

4.1. Relationships Among Biodiversity Indicators and Populations

The consistency in species diversity among the studied locations, as observed in this study and supported by Oliveira–Filho’s research [33], underscores the reliability of the obtained results. Concordia exhibits a high species richness with 75 registered species, albeit with a moderate coincidence rate of 31.4%. On the other hand, NP El Palmar displays a richness of 71 species, with a relatively higher coincidence rate of 34.3%. Gualeguaychú, while having a lower species richness with 60 species, still maintains a noteworthy coincidence rate of 33.3%. Hence, a considerable number of species and families associated with H. edulis have been successfully recorded in the studied populations. While in terms of alpha diversity, the obtained results and the compared literature seem quite disparate, it should be noted that the bibliographic source consists of a multi-year project that draws from many other sources, which could explain the lower number of species in this study. However, this information allows us to assert that the degree of species representativeness among sites is, at the very least, similar.

In general, regarding richness, abundance, the Shannon index, and dominance, less favorable conditions are observed in NP El Palmar compared to Gualeguaychú. The lowest values of richness and abundance recorded in NP El Palmar may be attributed to the majority of H. edulis trees being isolated and located outside areas of dense vegetation. As stated by Micou [34], in the riparian areas with dense and closed vegetation and a significant presence of Ligustrum lucidum, which is considered an invasive species and a threat to the conservation of regional biodiversity, H. edulis trees were not found. These reasons might lead to the assumption that H. edulis is, in turn, adapted to specific stands within the landscape’s heterogeneity.

Overall, it is suggested that for the three sites, there is a group of species that are relatively dominant in each community, while others have a less pronounced presence. This indicates a non-uniform distribution of species abundance, but the value is not extremely high, which could be considered moderately positive in terms of biodiversity. The higher dominance in NP El Palmar could be explained due to many species being surveyed only once, while a few species were recorded more frequently, such as Solanum mauritianum (26), Scutia buxifolia (17), and Myrrhinium atropurpureum (14). Solanum mauritianum (38) and Asparagus setaceus (31) were two markedly dominant species in Gualeguaychú, while only three species were recorded once. The same trend was observed with Pielou equitability, although no differences were found.

While the Shannon index has significant differences between NP El Palmar and Gualeguaychú, we cannot strictly conclude differences in site biodiversity based on this indicator, as it measures entropy and the state of the complexity rather than biodiversity [35]. In other words, we could conclude that there is greater biological complexity, but not necessarily greater diversity per se in Gualeguaychú compared to NP El Palmar. Furthermore, the indicators that measure biodiversity more strictly, such as evenness and Margalef, showed that there are no conclusive differences between the sites where H. edulis grows. Broadly speaking, the values of biodiversity indicators might seem not very encouraging, but it should be kept in mind that the surveys were only restricted to woody and semi-woody species, the precipitation and average temperature regime corresponds to a subtropical to temperate transition zone, and it is known that these climatic variables are correlated with the quantity of species and individuals [36]. It should also be considered that comparative differences with other studies could be due to the fact that the surveys were based on species associated with a single species.

4.2. Impact of Human Activity on Native and Exotic Species Dynamics

The relationships between native and exotic species provide insight into the impact of human activity. The anthropic indicator shows Gualeguaychú has the lowest native-to-exotic species ratio, suggesting higher anthropization. While biodiversity indicators may appear favorable, they often include exotic species that disrupt the original ecological balance. Introductions of non-native trees and shrubs have caused invasive species to spread, negatively impacting ecosystems globally [37]. In Gualeguaychú, despite limited public access, the lower ratio (0.70) suggests that nearby forestry activities contribute to the establishment of non-native species. In contrast, NP El Palmar, despite tourism and recreational use, maintains a higher proportion of native species (0.78), likely due to its conservation status. Concordia, with the highest anthropic indicator value (0.85), seems less impacted by exotic species despite surrounding recreational activities.

These findings highlight the complex ways human activities influence local biodiversity. Even minor disturbances can significantly shift species composition, as the introduction of exotic species often leads to the displacement of native flora, affecting ecosystem functions and resilience. Managing the introduction of non-native species and closely monitoring their impact should be central to conservation efforts.

4.3. Vegetation Community Dynamics and Multivariate Analysis

Also, it is demonstrated that individuals of H. edulis are found in different vegetation communities of the riparian forest of the Uruguay River and are adapted to different conditions of biodiversity, competition, and environment in terms of accompanying woody and semi-woody species. Other studies have successfully set a precedent for combining PCoA with Hierarchical Cluster Analysis [38], as they perform a hierarchical clustering of the observations and then represent them in an ordination obtained with PCoA using the same distance measure used in the clustering, for example, as conducted by Ulloa et al. [39]. Other studies have even confirmed differences in the composition of tree vegetation in the gallery forests of the Uruguay River according to climatic, physiographic, and edaphic environment [23,40]. In the Cluster Analysis, NP El Palmar and Gualeguaychú show a lower distance explained by vegetation composition. The similarities could be explained by the species Solanum mauritianum, Scutia buxifolia, Schinus longifolius, and Fuchsia magellanica being present in all three sites. The three statistical analysis tools, i.e., cluster analysis, PCoA, and discriminant analysis, complement each other and consistently demonstrate that the plant communities where H. edulis spontaneously grows are different, and the composition of vegetation among populations is heterogeneous. Additionally, as shown by Cluster Analysis, a closer similarity is observed between El Palmar and Gualeguaychú, which could be explained by a greater difference in annual average temperature and precipitation compared to Concordia.

4.4. Native Species for Enhancing Biodiversity in Cropping Systems

Some registered native species worth highlighting for possible incorporation into farming systems to improve biodiversity are Allophylus edulis, Butia yatay, Eugenia uniflora, Eugenia uruguayensis, and Muehlenbeckia sagittifolia. Allophylus edulis, commonly known as “chal-chal,” is a small tree or shrub with edible fruits rich in antioxidants and medicinal properties, traditionally used for gastrointestinal disorders and inflammation [41,42]. Butia yatay, or “yatay palm,” produces nutritious edible dates that can be transformed into value-added products and serves as a vital nectar source for honey production while providing habitat for wildlife [43,44]. Eugenia uniflora, known as “Surinam cherry” or “pitanga,” offers delicious sweet-tart fruits and has been used traditionally for digestive issues and respiratory problems; it also shows promise in breeding programs and contains bioactive essential oils [45,46,47,48]. Eugenia uruguayensis possesses antimicrobial and anti-inflammatory properties due to its leaf oil compounds [49], making it a profitable alternative for agricultural production [50]. Lastly, Muehlenbeckia sagittifolia, or “wire vine,” is a hardy climbing plant with small, edible fruits and multiple uses in erosion control and landscaping [51].

Incorporating these native species into agroforestry practices can enhance biodiversity, provide economic opportunities, and support sustainable agricultural practices. Future studies should explore their full potential and develop best practices for their cultivation and use. While these five species have been highlighted for their particular potential, it is important to note that other species found in these sites likely also possess valuable uses.

5. Conclusions

This study successfully recorded a considerable number of species and families associated with H. edulis in the studied populations indicating a diverse plant community within the habitat of H. edulis.

Biodiversity indicators, including richness, the Shannon index, and dominance revealed variations among the studied sites. These indicators provide insights into the ecological complexity and community structure within each population.

The anthropic indicator highlighted the impact of human activity, with differences in the ratio of native-to-exotic species among the populations, suggesting varying degrees of human influence and potential conservation challenges.

Statistical multivariate analyses, such as cluster analysis, PCoA, and discriminant analysis, consistently demonstrated differences in plant communities among the populations. These variations reflect the heterogeneity of the landscape and the adaptability of H. edulis to different ecological conditions and associated species.

The results of this study not only contribute to the sustainable management of H. edulis, but also have broader implications for enhancing agroforestry practices with similar species. Among the species grown along with H. edulis, this study successfully identified five promising native plant species for agroforestry applications: Allophylus edulis, Butia yatay, Eugenia uniflora, Eugenia uruguayensis, and Muehlenbeckia sagittifolia. These species offer a wealth of benefits including edible fruits, medicinal properties, ecological advantages for biodiversity and bioremediation, economic opportunities through fruit production and handicrafts, and support for sustainable agricultural practices.

Results obtained can serve as baseline information for future research on the dynamics of vegetation in these areas and on the studied H. edulis species. Finally, these findings contribute to understanding how wild species like H. edulis adapt to different plant communities, which might be valuable for developing new agroecological approaches or identifying potential companion planting species in future agricultural systems.