Climate change can influence the distributions of species and communities in mountain environments, but responses may differ among vegetation belts and may be strongly modified by local habitat conditions. Although distributional shifts have been studied widely, much evidence comes from alpine and arctic environments, while detailed resurvey studies focusing on individual species across broader elevational gradients remain comparatively rare. Here, we compared past (2000–2002) and current (2019) distributions of two closely related grasses in the Giant Mountains (Czech Republic): Anthoxanthum odoratum (an allotetraploid primarily of lower elevations) and A. alpinum (a diploid occurring mainly at higher elevations). We assessed changes in their occurrences over two decades and tested which environmental factors were associated with current occurrence, appearance and disappearance. Overall, elevational ranges changed only modestly, with weak evidence that A. odoratum now occurs at slightly higher elevations than in 2000–2002. A. alpinum also appeared at a small number of lower-elevation sites. Changes in occurrence were associated with local habitat characteristics (vegetation and bryophyte cover, nutrient and soil moisture indicator values, and community composition) and were largely independent of elevation as a broad proxy for macroclimate. These results suggest that fine-scale habitat context is a key correlate of distribution and recent distributional dynamics in this species pair.
Effects of topography on the composition of trees and seedlings have been demonstrated in many tropical forests. Less attention has been paid to interannual changes in seedling establishment as a potential driver of the species composition. We explored the associations of neighbouring vegetation physiognomy and the abiotic environment (mainly topography) with the composition of tree seedlings. To reveal the shifts in habitat preferences through ontogeny, we compared the compositional response of tree composition to the same abiotic variables. Further, we evaluated interannual differences in seedling composition and composition of newly recruited seedlings. Seedling composition was monitored in 800 permanent quadrats within the 50 ha forest dynamics plot in the lowland tropical forest in Papua New Guinea for five consecutive years. Redundancy analyses were used to reveal the effects of abiotic and biotic factors on the composition of trees and seedlings. The ridge-valley position and the slope steepness were associated with the distribution of seedlings and even more so of trees. The effect of neighbouring vegetation physiognomy on seedlings was negligible. We found mostly concordant responses of established trees and their seedlings to the ridge-valley gradient, although some species exhibited preferential shifts during their ontogeny. The species composition of seedlings varied significantly over consecutive years. Topography appears to shape the species composition with varying strength depending on the species identity and through the ontogeny of individual trees. Strong interannual variation in the distribution and identity of newly recruited seedlings can contribute to the maintenance of local tree diversity.
The present study provides a detailed macro- and micro-morphological and anatomical description of seeds of 13 Cistaceae taxa (two Fumana and 11 Helianthemum), some of which are presented here for the first time (the near-endemic H. crassifolium subsp. sphaerocalyx and the rare H. sancti-antoni, H. sessiliflorum, H. vesicarium, and Helianthemum virgatum subsp. ciliatum). The seed shape, size, texture, hilum characteristics, epidermal cell patterns, anticlinal and periclinal cell walls, seed-coat ultrastructure, and the shape, thickness, and arrangement of different seed-coat layers were comparatively examined using light and scanning electron microscopy methods. The taxonomic significance of these characteristics is discussed, and a determination key using seed morphological and anatomical attributes is presented. Multivariate analyses of seed characters compared the previous and current sectional classifications of the two studied genera. Based on seed morphological and anatomical traits, our results support inclusion of H. aegyptiacum in sect. Helianthemum. This finding agrees with recent systematic treatments of the genus. Moreover, our results support the treatment of H. sessiliflorum as a distinct species, rather than a synonym of H. lippii.
Forest road verges are common secondary habitats in managed forest landscapes, however their vegetation development remains insufficiently documented. We investigated the successional changes in ground vegetation on newly built forest road verges in Latvia over an eight-year period using six repeated surveys, analysing the taxonomic diversity of vascular plants and bryophytes, their ecological indicator values, Rao’s quadratic entropy as a measure of niche differentiation, and the functional trait composition of vascular plants based on Grime’s CSR strategies and Raunkiær’s life forms. Our results showed a continuous increase in taxonomic richness throughout the study period, whereas niche differentiation increased mainly after the first year following road construction and remained relatively stable thereafter. Regarding the examined ecological indicator values, nutrient availability consistently showed the highest niche differentiation, whereas light and moisture showed comparatively lower variation. Functional composition shifted from ruderal-dominated communities to an increasing representation of stress-tolerant and competitive vascular plant species. The results from the mixed-effects models revealed high spatial variation among road sections, indicating that early secondary succession on forest road verges is shaped by both successional processes and local environmental conditions.
The flowers of members of the Capparaceae are characterized by an open morphology with numerous stamens, suggesting generalist pollination systems. Despite the conservative nature of this floral form within the family, there is evidence of significant variation in other traits, as indicated by sporadic records of different pollination systems. The research on the pollination biology of the Capparaceae seems to be sparse and fragmented, revealing an Eltonian shortfall in relation to plant–animal interactions in this family. Our objectives were: (1) to compile information from the literature on floral traits and pollination systems in the Capparaceae; (2) to summarize current knowledge about reproductive systems in the Capparaceae; (3) to test the existence of a latitudinal gradient in functional and ecological specialization within the family; and (4) to identify priority areas and species for further studies on pollination. We found considerable variation in floral traits, including colour, size and the number of stamens. Our results show a high degree of functional specialization, with the largest species being pollinated mainly by bees. We observed differences along a latitudinal gradient: Whereas the richness of pollinators reaches the peak near the equator, specialized groups, such as bats and moths, are restricted to tropical zones, making extratropical species more dependent on widespread pollination by bees. Variations in reproductive systems, including changes between self-incompatibility and self-compatibility, suggest a high degree of reproductive plasticity in response to environmental pressures and the scarcity of pollinators. We emphasize the need for further research on pollination ecology in Africa and South America, where many species of the Capparaceae are at risk of extinction.
Most demographic studies of ferns have been conducted in temperate or tropical humid environments. In this study, we examined the microhabitat preferences and population dynamics of Myriopteris aurea and Pellaea ternifolia in a seasonally dry environment. We conducted three annual censuses and used transition matrix models to estimate the stable population structure, reproductive value and finite growth rate (λ) of each fern population. We calculated the latter for three scenarios of different rainfall probabilities (25
The genus Pinguicula is striking in that all its extant members are considered carnivorous. Pinguicula is also recognized for its mountainous and restricted distribution and, consequently, for its high vulnerability to human activities. Mexico harbours nearly half the species of this genus worldwide. We analysed the geographical patterns of Mexican Pinguicula species to characterize the threat level according to criterion B2 (area of occupancy) of the International Union for Conservation of Nature. We also performed an endemicity analysis to identify areas of endemism and their relationship with Mexican protected natural areas. Finally, we applied a protocol of Systematic Conservation Planning to assess the current representativeness of Pinguicula species within existing Mexican protected areas. Of the total 52 species studied, 67
Dioecious Juniperus taxa in the Hindu Kush mountains are facing threats from human activity and climate change, emphasizing the need for demographic data to assess taxa- and sex-specific microhabitat responses. We investigated dendrometric traits, the sex ratio, sex-specific growth (cm · year⁻1), and reproductive effort of three Juniperus taxa along an elevational gradient (2,400–3,500 m a.s.l.). Vegetation data from 30 stands were analysed, with the sex ratio determined by counting male and female individuals, growth rates assessed through dendrochronology, and reproductive effort quantified by counting cones and viable seeds. J. excelsa showed significantly greater diameter (> 24.3 cm), height (> 5.24 m), and age (> 132 years) than the other Juniperus taxa (P < 0.02), whereas J. semiglobosa had the highest growth (> 0.18), especially in males (0.20, P = 0.04). The sex ratio was relatively balanced in J. excelsa (0.8) and J. semiglobosa (0.87), while a more skewed sex ratio (0.3) was recorded in J. excelsa subsp. polycarpos, which also occupied a narrow elevational range (2,628–2,929 m). By contrast, J. semiglobosa dominated broader and higher elevations (2,546–3,450 m), reflecting its greater ecological amplitude. Cone production in J. semiglobosa and J. excelsa was moderate, whereas it was significantly lower in J. excelsa subsp. polycarpos. Overall, seed viability was low (26–34
Diversity within species is evolutionarily important, but precisely how and under what conditions it affects ecological interactions is still coming into focus. Addressing this requires us to investigate the effects of intraspecific diversity across a wide variety of contexts, including in species types that are underrepresented in prior research. In this study, we sought to determine the separate and interactive effects of genotypic diversity and nutrient addition on Solidago sempervirens (seaside goldenrod), a common but not dominant salt marsh plant species. Using a trait survey, feeding preference experiment, and common garden experiment, we asked 1) whether traits related to growth strategy and susceptibility to herbivory differ among S. sempervirens genotypes and 2) how soil nutrients and genotypic diversity of intraspecific competitors affect plant growth strategy and susceptibility to herbivory. We found that traits related to growth strategy varied among genotypes in the lab and that genotypes adopted different growth strategies. In the common garden, genotypic diversity also affected plant growth strategy; plants grew more leaves in genotypic polyculture and more shoots in genotypic monoculture, even as total aboveground biomass did not differ. This was likely because the optimal competitive strategy differs when competitors’ traits are similar versus dissimilar. Diversity did not affect the amount of herbivory that plants experienced in the common garden despite differences among genotypes in the feeding preference experiment. Nutrient addition led to more shoots and greater herbivory, but there were no interactions between nutrient addition and genotypic diversity. The lack of interaction indicates that in this situation, the effect of genotypic diversity does not vary with nutritional context. Whether nutritional context alters the impact of genotypic diversity may depend on the magnitude of nutrient stress or characteristics of the focal species.
Island coastal ecosystems are highly vulnerable to natural disturbances and human activities, often resulting in fragmented habitats and altered regeneration conditions for native plant populations. Here, we present a single-season census of Heliotropium arboreum across six coastal populations on Hainan Island, Wuzhizhou Island and the Xisha Islands, describing basal-diameter (BD) size-class structure and associated habitat conditions. Across sites, most individuals were concentrated in intermediate BD classes (approximately 63–86
Iris aphylla is a threatened species in Romania, otherwise distributed across Central and Eastern Europe, extending into the Caucasus and Asia Minor Anatolia. This study aims to identify its environmental requirements and phytocoenological preferences in Romania. To this end, 302 phytocoenological relevés were analysed for vegetation. Information is presented on bioclimatic and topographical factors. For multivariate analysis, detrended correspondence analysis (DCA) and canonical correspondence analysis (CCA) were applied. The results show that I. aphylla was most frequently recorded in the associations Taraxaco serotinae-Festucetum valesiacae and Jurineo transylvanicae-Stipetum pulcherrimae. The representative EUNIS habitat for I. aphylla is R1B Continental dry grassland (true steppe). Cluster analysis separated 302 relevés into six distinct floristic groups. Furthermore, I. aphylla occurred at elevations ranging from 300 to 599 m a.s.l. on very steep slopes with south-eastern and south-western aspects. Iris aphylla was also found in areas with annual precipitation ranging from 400 to 600 mm and annual mean temperature between 5 and 10°C. Canonical correspondence analysis revealed that elevation was the most significant factor influencing the floristic composition of vegetation with I. aphylla. In conclusion, I. aphylla is associated with dry continental grasslands, and its distribution and abundance are determined by climatic (annual precipitation) and topographic (elevation) gradients. Habitat degradation caused by land use change and overgrazing is a major threat, which requires specific grassland management to ensure the long-term conservation of the species. Habitat protection by limiting forest plantations and infrastructure development is necessary. Regular monitoring and further ecological studies on the effects of climate change will support the adaptation of conservation strategies.
Research on Dracaena (Asparagaceae) in Asia has been relatively limited in recent decades. Numerous taxonomic and nomenclatural issues remain unresolved. In Indonesia, the species diversity of Dracaena remains uncertain. To address this, field explorations have been conducted on several Indonesian islands, including Sulawesi, where several Dracaena specimens of unclear taxonomic status were discovered. Herbarium specimens collected from Sulawesi have been examined, and in addition to the macromorphological characters, micromorphological observations using scanning electron microscopy (SEM) were also carried out. A global conservation status assessment was conducted for all species based on IUCN criteria. Three species of Dracaena were documented from Sulawesi: D. angustifolia, D. banggaensis, and D. multiflora. Dracaena banggaensis is newly proposed and described as a distinct species in this study. It is closely related to widespread southeast-Asian D. elliptica in terms of inflorescence type but differs in leaf and flower characteristics. The micromorphology of Dracaena species showed many similarities among the species, but D. banggaensis was distinguished by its raphide crystals and rough seed coat. According to the IUCN criteria, D. angustifolia and D. multiflora is classified as Least Concern (LC), while D. banggaensis is assessed as Critically Endangered (CR). A description, identification key, and illustrations of these species is provided.
Moroccan populations of Alnus glutinosa represent a climatic relic. These populations are isolated and threatened by both climate change and human activities. Using leaves from twelve populations of A. glutinosa, this study reveals intraspecific variation in leaf traits and explores how these traits respond to climatic, geographical and hydrological factors. Descriptive statistical analysis and nested analysis of variance revealed significant differences in 22 leaf traits of A. glutinosa, both among and within populations, with a broad range of coefficients of variance (10
Prolonged drought stress at mild/moderate intensities is assumed to be a realistic situation that natural tree populations will face in the future warming climate. Here we performed a six-week experiment during which water supplies were controlled by applying a repeated cycle of intermittent watering to the current-year seedlings of Fagus crenata originating from two snowy regions in Japan, in order to examine the effects of moderate, prolonged, but gradual, soil drought stress on them as well as to determine any site-common and/or -specific patterns. Compared to the well-watered seedlings, there were no or limited changes in stomatal conductance, leaf water content, root-to-shoot ratio, and concentrations of total soluble sugar and free-proline in leaves of the seedlings that received intermittent watering over the three census dates. In contrast, the seedlings from both sites that received intermittent watering exhibited significant increases in the concentration of malondialdehyde in leaves on every census date, compared to well-watered seedlings. There were very few notable between-site differences in any of the phenotypic traits mentioned above. Due to the moderate intensity of drought stress combined with unexpectedly high vapor pressure deficit and low light intensity in the greenhouse, we detected neither drought stress-driven stomatal closure nor cellular osmotic balancing; however, reactive oxygen species may have been produced in leaves of the seedlings. These findings imply that the concentration of malondialdehyde is a promising candidate biochemical marker for detecting early signs of adverse effects on F. crenata seedlings under soil drought conditions in the future warming climate.
A revision of the Taraxacum section Erythrosperma in the Republic of Moldova, based on fieldwork and the study of herbarium specimens, has revealed two new species, T. parnassicum and T. persicum, for the country’s flora, confirmation of the occurrence of the sexually reproducing species T. erythrospermum s. str., and records of plants belonging to the T. scanicum group, previously never reliably documented in the Republic of Moldova. These findings are supplemented or supported by descriptions of the species and their distribution, photographs of herbarium specimens, and chromosome numbers and ploidy information. The chromosome number of T. persicum, 2n = 24, is reported here for the first time. An identification key to T. sect. Erythrosperma in Republic of Moldova, compiled based on the newly collected material, is presented.
The encroachment of shrub species into mountainous grasslands threatens global biodiversity and ecosystem stability. Shrub encroachment is influenced not only by the environmental characteristics of the region, but also by specific traits of the encroaching shrub species, such as leaf nutrient concentration. However, the topography-driven changes in the leaf nutrient concentration of encroaching shrub species in mountainous grasslands remain largely unexplored. Here we examined how landscape topography and selected soil edaphic properties influence the leaf nutrient composition of the encroaching shrub Euryops floribundus N.E. Br in three mountainous grassland sites in eastern South Africa. Each landscape site was surveyed and demarcated into three topographic positions: downslope, midslope, and upslope. In each topographic position per site, six 10 m x 10 m plots were randomly selected to collect leaf samples from Euryops floribundus, along with soil samples taken from the topsoil layer. We found evidence that landscape topography, nutrient availability and associated chemistry of the soil influences leaf nutrient concentrations of the encroaching Euryops floribundus. Specifically, leaf phosphorus concentration in the downslope position was 33% higher compared to upslope position in Manzimdaka, and correlated to effective cation exchange capacity, exchangeable acidity and acid saturation of the soil. Leaf potassium concentration increased by 22% in downslope positions compared to upslope positions in Tsengiwe. A similar trend of leaf potassium content was observed in Manzimdaka, although a significant increase of 20% occurred between downslope compared to midslope positions. We also observed a 37% and 28% increase in leaf zinc concentration in downslope positions compared to upslope positions in Tsengiwe and Manzimdaka, respectively. Furthermore, leaf manganese was 63% lower in downslope positions compared to upslope positions in Upper Mnxe. This study provides valuable insights into the impact of landscape topography on the nutrient concentration of encroaching shrub species in mountainous grasslands. The examination of leaf nutrient traits along a topographic gradient will lead to improved understanding of plant strategies at local scales and give much needed insights into the ecological mechanisms that influence the dominance and persistence of Euryops floribundus monoculture stands in mountainous grasslands.
Determining the pollination system of a plant species solely based on floral attributes can be quite challenging in certain situations. This is particularly true for seemingly generalist systems, such as brush-type flowers, whose reward are typically easily accessible and do not exhibit an obvious fit to floral visitors. Among angiosperm families, the Capparaceae is particularly distinguished by the predominance of brush-type flowers. The aim of this study was to investigate the pollination ecology of a pair of sympatric plant species with brush-type flowers from the Capparaceae, to understand how reward availability and mechanical fit to floral visitors might determine potential levels of specialization. We described the sequence of anthesis, nectar dynamics and retention mechanisms within the flowers, observed the behaviour of floral visitors in terms of timing and pollination effectiveness, and tested their mechanical fit to the flowers. The anthesis of the species under study encompasses different groups of diurnal, crepuscular and nocturnal pollinators. Continuous nectar secretion ensures reward availability throughout anthesis, with the nectar, although fully exposed, remaining adhered to the base of the filaments. Carpenter bees and hawkmoths alternated as the most frequent pollinators, although both plant species were also pollinated by bats. The ideal mechanical fit for pollination in brush-type flowers was determined primarily by the behaviour of the pollinators on the flowers rather than a relationship with their mouthparts. This study reveals the necessity of detailed investigations to determine the pollination system in brush-type flowers.
Upper Andean tropical forests represent a unique biodiversity region with distinctive floristic composition. However, our understanding of functional trait variation, its differences between growth forms, and the relationships between traits remains limited in this region. This study aimed to analyse the variation in leaf anatomical traits in upper Andean tropical forests of Colombia, compare differences between trees and shrubs, and examine trait correlations. Leaf anatomical traits from 38 tree species and 25 shrub species were obtained from 189 individuals. Measured traits included cuticles, epidermis, hypodermis, palisade and spongy mesophylls, vascular bundles, and air spaces. Significant differences in all anatomical traits were found between species, highlighting the wide variety of tissue combinations in shapes and sizes. On average, trees exhibited thicker protective tissues than shrubs, but only the percentage of adaxial cuticle thickness was statistically significant. These minimal differences are likely due to limited vertical stratification, lower canopy height and reduced aboveground biomass, which decrease the selection pressure for shade-tolerant species with thicker leaf anatomical traits. Potential trade-offs were identified within mesophyll tissues (an inverse relationship between palisade and spongy tissues), between photosynthetic efficiency and leaf protection (an inverse relationship between the palisade/spongy ratio and the adaxial cuticle/abaxial cuticle ratio), and between cell aspect ratios of epidermis and mesophyll tissues (an inverse relationship between the aspect ratio of epidermis cells and that of palisade and spongy cells). This is the first study that analyses the leaf anatomical basis underlying the life-history strategies of trees and shrubs in Andean montane forests and the potential trade-offs involved.
The Brazilian Atlantic cloud forests are critical biodiversity hotspots currently under threat from urbanization, agricultural expansion, and climate change. This study, conducted in upper montane cloud forests in Urubici, Santa Catarina State, Brazil, examines the distribution of regenerating tree species across different height classes from the understory (<1m) to the canopy, revealing their presence within unique nebular conditions. We observed 1,342 trees (23,222 ind.ha-1), covering 34 species across 22 genera and 16 families. Complex Network Analyses identified pronounced vertical stratification, with species showing notable specialization and moderate to high levels of differentiation in their height class preferences. Generalized Linear Latent Variable Models (GLLVM) highlighted species-specific patterns, with some species being more abundant in lower height classes and others in higher ones. Despite the expected homogeneous light conditions due to high cloudiness and fog, our findings reveal clear distribution patterns at different forest layers. These insights emphasize the importance of vertical stratification in cloud forest conservation, highlighting the need for strategies that address distinct ecological requirements at different forest layers.
This study examines the weediness potential of spontaneous vegetation in an agroecosystem undergoing an agroecological transition in Buenos Aires Province, Argentina. We sampled parcels under three types of agronomic management—conventional, agroecological with annual crops and agroecological with perennial crops—along with non-managed terraces. We assessed floristic and functional diversity based on seven traits associated with weediness: clonality, growth form, life cycle, dispersal syndrome, plant fecundity, maximum potential vegetation height, and seed size. In floristic terms, a principal component analysis clearly separated the parcels into three distinct groups: terrace, conventionally managed, and agroecological. The weediness potential of spontaneous vegetation showed distinct differences across the types of land management. Conventional parcels were characterized mainly by high-weediness species (non-clonal annuals, herbaceous, with high fecundity and having small seeds) whereas terrace parcels were characterized by low-weediness species (shrubby perennials with hemerochoric dispersal, low fecundity and large seeds). Agroecological parcels exhibited mixed weediness traits, and those with annual crops were largely composed of herbaceous non-clonal annuals with intermediate traits and hemerochoric dispersal. Agroecological parcels with perennial crops featured mainly graminoids, annuals and stoloniferous species with intermediate traits. Consequently, terrace parcels are unlikely to contribute significantly to common weedy vegetation. Understanding functional traits related to the weediness of spontaneous vegetation is essential for agriculture, as it can help promote beneficial species and control harmful ones, supporting the transition to agroecological practices and improving ecosystem processes while reducing pesticide use.
