Search Results (35)

Urban parks can act as refuges for biodiversity, but their ecological value depends on the structure and composition of the vegetation they contain. This study evaluated the relationship between vegetation attributes and bird diversity in urban parks of metropolitan Arequipa, Peru, while considering daily variation across three time periods. Vegetation and bird communities were jointly characterized in 12 urban parks using point counts, alpha-diversity metrics, mixed models, multivariate ordinations, taxonomic beta diversity, and functional diversity metrics. We recorded 21 bird species and 17,591 individuals in 291 surveys. Bird richness responded mainly to integrated gradients of park size, tree-shrub structure, and shrub-herbaceous vegetation cover, whereas Shannon diversity increased with the total number of plant families and declined toward the afternoon. Bird composition was associated with vegetation gradients, and taxonomic beta diversity was high and dominated by species turnover. Floristically dissimilar parks also supported more differentiated bird communities. Abundance-weighted functional indices responded to the shrub-herbaceous gradient. These findings indicate that vegetation structure and floristic quality are key to enhancing the ecological value of urban parks in arid cities. Full article

This manuscript will present an advancement of transformative research that has been conducted at Oak Ridge National Laboratory (ORNL) over a 25-year period (2000–2025) on a variety of environmental and biological matrices. These investigations derived a fundamental understanding of how elemental detection and analysis of these matrices led to the knowledge and discovery of natural processes in plants and the environment. Each project led to the initiation of a new research area which unearthed awesome and novel breakthroughs. Highlights are listed below: 1. The preliminary research at ORNL centered on the detection of aerosols utilizing Laser-induced Breakdown Spectroscopy (LIBS) technology. The Clean Air Act Amendment (CAAA) of 1990 highlighted the importance of identifying hazardous air pollutants (HAPs) due to their impact on environmental and human health, thereby underscoring the need to detect various toxic elements. Research in aerosol chemistry aimed to identify these harmful elements released by factories during periods of increased emissions in their manufacturing processes. LIBS emerged as the most effective method for real-time, in situ measurements of metal species in both gaseous and aerosol phases. 2. An understanding of the presence of total carbon in soils gives perspective on how to develop carbon sequestration strategies. The recognition that carbon sinks can evolve back to carbon sources to emit back to the atmosphere was an important consideration. Also, the concentration of carbon in soil indicates the health of land areas for growing crops successfully. 3. The direct detection of most of the elements in a wood sample in a single emission spectrum, without sample preparation, encouraged the research to use the LIBS technique for preservative treated wood coupled with use of multivariate statistical methodology. Additionally, it encouraged the researchers to try to differentiate natural woods from different parts of the country, and it was successfully demonstrated that LIBS coupled with MVA analysis could differentiate wood of different species from each other and of similar species grown in different environments based on their elemental spectra. This was a breakthrough since it revealed a systematic approach to connect elemental scarcity and abundance to either drought or typical rainfall conditions for the hardwood trees grown in specific areas. 4. Furthermore, the research progressed to reveal physiological and developmental processes contributing to biomass production such that the variation in leaf elemental composition increases our understanding of terrestrial nutrient cycles, as well as tracking the transfer of toxic elements from soils to living organisms. 5. Recently another breakthrough viz., ionomics initiated the correlation of elements to specific genes, uncovering the function that the element performed in the plant. More recently, this has been extended from plants to fungi as well as fungi growing in symbiotic relations with plants. Full article

Soil physicochemical and biochemical properties are fundamental to soil processes and ecosystem functioning in forest environments, yet their responses to dominant tree species in humid montane regions remain largely ununderstood. This study examined the effects of three widespread broadleaf species—Quercus pontica, Quercus petraea, and Fagus orientalis—on soil physical, chemical, and biochemical properties in natural forests in the Eastern Black Sea region, where these species play key ecological roles in structuring forest composition and biogeochemical processes. A total of 15 soil samples (5 per forest type) were collected under comparable climatic and geological conditions and analyzed for particle-size distribution, pH, electrical conductivity (EC), soil organic carbon, and key microbial activity indicators. Significant differences in soil properties were detected among forest types. Soils under Q. pontica were characterized by the lowest silt content and pH, but the highest sand content, soil organic carbon, microbial biomass carbon (C_mic), and microbial respiration. In contrast, soils under Q. petraea exhibited the highest clay content and pH, whereas F. orientalis soils showed lower sand content, EC, soil organic carbon, microbial biomass nitrogen (N_mic), and basal respiration. Multivariate analyses revealed that soil texture, pH, and C_mic are key factors driving soil differentiation across forest types. These patterns indicate that species-specific litter inputs and belowground processes regulate soil biochemical functioning by altering resource availability and habitat conditions. Crucially, this study sheds light on the soil-forming responses of these ecologically dominant species and their impacts on carbon cycle pathways and microbial dynamics at the regional scale. Overall, the study shows that tree species identity is a critical factor influencing soil function, with significant consequences for forest management, carbon sequestration strategies, and ecosystem resilience to changing environmental conditions. Full article

Forest fertilization is commonly used to enhance tree growth and carbon (C) sequestration, especially in nutrient-poor boreal forests. However, it also poses several environmental risks, including shifting ground vegetation community composition and a reduction in species diversity. This study evaluated how ground vegetation species composition responded to forest fertilization with ammonium nitrate and wood ash across forest stands with varying dominant tree species, age groups, and site types. Ground vegetation assessment was performed during the one to three years following fertilizer application. We conducted detrended correspondence analysis (DCA) to examine compositional differences in ground vegetation between control and fertilized plots and to identify ecological factors underlying dataset variation. Ordination was based on species percentage cover data, with soil chemical parameters and stand inventory metrics providing environmental context for interpreting the results. Additionally, permutational multivariate analysis of variance (PERMANOVA) was conducted to evaluate whether vegetation composition differed across the experimental design factors. Forest site type and stand developmental stage were the primary drivers of understory composition, with fertilization effects being statistically significant but ecologically modest (0.9–14.2% of variation explained by fertilization in PERMANOVAs). Wood ash treatments showed greater compositional divergence from controls than ammonium nitrate alone. Fertilization effects varied with stand age, with significant responses in middle-aged and pre-mature Norway spruce stands but not in young stands. Despite modest compositional changes, fertilization achieved substantial productivity gains (volume increment increases of 20–60% compared to controls depending on species and site conditions), suggesting that moderate fertilization for timber production can be implemented without dramatic changes to ground vegetation. These results reflect short-term responses (1–3 years after fertilization) and should therefore be interpreted as early ecological effects rather than long-term ecosystem changes. Full article

Sexual systems critically influence woody plant evolution and forest functioning, yet their global patterns and environmental drivers remain understudied. Investigating the environmental correlates of sexual systems in woody plants is essential for developing targeted conservation and restoration strategies for forest ecosystems. We analyzed sexual system composition of 3595 woody species from 30 ForestGEO forest plots spanning tropical, subtropical, and temperate zones in the Northern Hemisphere. Species were classified by sexual system (hermaphroditism, monoecy, and dioecy) and growth form (trees and shrubs). Community-level patterns were assessed across climatic zones, and the relative contributions of climatic, spatial, and topographic factors were quantified using multivariate and network-based analyses. We observed the following: (1) Sexual system composition exhibited clear climatic differentiation: dioecious species predominate in tropical forests, while monoecious species increased in dominance toward temperate regions. (2) Climatic variables, particularly temperature and precipitation, accounted for more variation in sexual system composition than spatial or topographic factors, although their relative influence differed among climatic zones. (3) Distinct life-form-specific patterns were detected: sexual systems of trees were more strongly associated with broad-scale climatic gradients, whereas those of shrubs were more closely linked to spatial structure and local environmental heterogeneity. Together, these results demonstrate that climate is a dominant but life-form-dependent driver of sexual system biogeography in woody plants, improving trait-based understanding of forest biodiversity responses to climate change. Full article

This study investigated the structure of vegetation communities in Yongneup, a representative montane peatland on Mt. Daeamsan, Korea. It also identified key microenvironmental drivers shaping their distribution. We surveyed 200 quadrats, analyzing herbaceous plant composition alongside peat depth, water level, and soil chemical properties. Multivariate analyses, including cluster analysis and classification tree analysis (CHAID), identified nine distinct vegetation communities. Each community was correlated with specific environmental gradients. Dominant species included Sanguisorba tenuifolia and Carex thunbergii var. appendiculata, with rare species such as Carex chordorrhiza and Drosera rotundifolia present in localized habitats. Peat depth emerged as the primary determinant of vegetation distribution, followed by hydrology and nutrient levels, including phosphorus and cations (Mg²⁺, Na⁺, K⁺). Our results underscored continuous ecological gradients rather than discrete zonation, aligning with ecological continuum theory. These findings provide a robust scientific framework for ecological monitoring and restoration. They also support Korea’s national wetland conservation policies and international commitments such as the Ramsar Convention. Full article

Tree ferns are ubiquitous in New Zealand forests, but there is limited knowledge of their role in urban plant communities and potential use in restoration. We assessed sixteen sites by measuring 200 m² plots to investigate how tree ferns influence vascular plant composition in Hamilton, North Island, New Zealand. The sixteen plots were assigned to four site type combinations based on restoration status (restored or unrestored) and tree fern presence, each with four plots. Average native plant species richness was higher at sites with tree ferns (36 ± 16; S = 68) than at sites without (19 ± 14; S = 41), with more diverse ground fern and epiphyte assemblages. Higher native plant richness at restored sites (34 ± 18; S = 62) compared to unrestored sites (20 ± 14, S = 44) was partially attributed to increased plant abundances. Multivariate analyses revealed differences in plant community composition among our site types. Angiosperms and conifers were less prevalent in plots with tree ferns, suggesting competitive relationships among these groups. However, tree ferns were associated with some shade-tolerant trees, such as Schefflera digitata J.R.Forst. & G.Forst. Indicator species of sites with tree ferns were mainly ground ferns and epiphytes (e.g., Blechnum parrisiae Christenh. and Trichomanes venosum R.Br.), whereas species with high fidelity to sites without tree ferns were pioneer trees and shrubs (e.g., Pittosporum eugenioides A.Cunn.). Community structure analyses revealed that total basal areas were highest at unrestored sites with tree ferns, but restored sites exhibited more diverse tree communities. Environmental predictors that correlated significantly with the compositional differences among our site types were tree fern basal area and restoration age. Our results highlight the need to reconsider the potential of tree ferns in current restoration practice. Tree ferns were found to augment native plant diversity in our study, indicating their potential to enhance urban ecological restoration projects in New Zealand. Full article

In Montenegro, coniferous forests play a key ecological role in maintaining ecosystem stability. Root-associated mycorrhizal fungi and saprotrophic fungi inhabiting forest soils are well known for their roles in nutrient cycling, organic matter decomposition, and supporting host tree health. In contrast, the fungal communities residing within conifer needles, despite potentially important ecological functions, remain largely underexplored, particularly in natural and marginal forest ecosystems such as those in the Balkans. This study aimed to investigate the diversity and community composition of needle-associated fungi in three native conifers: Picea abies and Abies alba (at the edge of their native range), and the endemic Pinus heldreichii, from different mountainous regions in Montenegro. High-throughput sequencing was conducted to assess fungal diversity and community composition. Dothideomycetes dominated fungal communities in all three tree species, followed by Leotiomycetes and Tremellomycetes. Multivariate analysis revealed distinct fungal communities in P. heldreichii, whereas fungal communities in A. alba and P. abies were partially overlapping. Functional classification showed a dominance of saprotrophic, pathogenic, and endophytic fungi, with P. heldreichii exhibiting the highest proportion of saprotrophs, while A. alba and P. abies showed a considerable proportion of pathogens. The findings highlight strong host specificity, biogeographical influences, and the ecological importance of fungal communities in coniferous forests. This study provides new insights into the diversity and functional roles of needle-associated fungi, emphasizing the need for conservation efforts to maintain microbial biodiversity in native forests of Montenegro. Full article

Epiphytic organisms are characteristic elements of the Andean dry forest, playing a crucial role in ecosystem diversity and functionality, but they are threatened by deforestation-related factors. The diversity of epiphytic lichens and bryophytes was recorded in the Pisaca Reserve, which has an artificial pond locally known as “Laguna Pisaca”, serving as a critical micro-watershed. This pond provides water services to the city of Catacocha, motivating local communities to protect its biodiversity. In each zone (low, middle and high), 10 plots of 5 × 5 m were established, where the presence and coverage of lichens and bryophytes were sampled in 4 trees per plot (120 trees). Richness and diversity (Shannon–Weaver and Simpson indices) were calculated. Generalized linear models (GLM) were used to analyze the effect of the zone on richness and diversity, and multivariate analysis was used to analyze species composition. A total of 90 species were recorded (65 lichens and 25 bryophytes), distributed in three zones: 74 in the high, 67 in the low and 41 in the middle zone. Species richness and composition showed significant variations in relation to the three zones, influenced by forest structure, small altitudinal changes and forests disturbance. The forests of the Pisaca Reserve harbor a great diversity of lichens and epiphytic bryophytes, which serve as refuges for biodiversity in the Andean dry montane forest of South Ecuador. Full article

Most fir species in the Mediterranean have small to medium-sized distributions, are often endemic and endangered, and are mainly found in relict areas, except for Abies alba. The IUCN Red List of Threatened Species identified Abies nebrodensis as the rarest conifer in the world, with only 30 adult trees remaining. Additionally, Abies pinsapo is threatened and limited to five fragmented locations in Spain and Morocco. This study aimed to characterize the seed terpene profiles of Mediterranean Abies species, such as A. nebrodensis, A. pinsapo, and A. alba, since morphological results showed minimal variation among the Abies populations examined. Terpenes were extracted using n-heptane and then analyzed by GC-MS. The chemical composition revealed the dominance of limonene and α-pinene as the main monoterpenes in all the species, while A. nebrodensis reported the considerable presence of germacrene D-4-ol and selina-6-en-4-ol as sesquiterpenes. The relative contents of most of the terpenes were significantly different among the species, and subsequent statistical multivariate analysis showed clear discrimination among three distinct groups. These results confirmed the suitability of the terpene profile as a potential tool to study chemotaxonomic differences between species from the same family. Moreover, the compounds identified can be interesting for further studies on plant defense against biotic stress to reduce the risk of species extinction caused by pests and diseases. Full article

Forest ecosystems are important for carbon storage but vary in their ability to do so. Here, we examined the relationship between stand state and ecosystem carbon storage in Pinus massoniana forests, pinpointed key stand state indicators affecting carbon storage, and provided a basis for management to enhance ecosystem carbon storage. We selected nine indicators representing structure (diameter at breast height (DBH) distribution, tree height distribution, stand density), vitality (stand dominance, stand growth, and tree health), and diversity (species composition, species diversity, and species evenness) to evaluate the stand state. Multivariate statistical analyses, specifically the Mantel test and Canonical Correspondence Analysis (CCA), were employed to explore the complex relationships between the stand states of P. massoniana forests and their carbon storage. We found that (1) stand state has a strong influence on carbon storage, but there is autocorrelation among the indicators of stand states; (2) stand structural attributes have a stronger association with ecosystem carbon storage than vitality and diversity. The primary stand state indicators associated with ecosystem carbon storage are DBH distribution (H), tree growth (B), stand density (K), tree height distribution (V), and species evenness (P); (3) the stand density (K) significantly affects the carbon storage in the vegetation layer, while the DBH distribution (H) significantly affects the carbon storage in the soil layer. None of the nine stand-state indicators, however, has a major influence on the carbon storage in the litter layer. Our results indicate that important stand-state indicators can be managed to improve forest quality and carbon storage in P. massoniana forests. Full article

Forest Orchidaceae are important for European temperate forests, yet their distribution and abundance have so far interested limited research. In three pure or mixed silver fir stands in the Foreste Casentinesi National Park (NP) (Northern Apennines, Italy) we analysed how structural traits in mature and old-growth forests affected orchid communities in terms of abundance of the main genera, trophic strategy and rarity in the NP. We established three 20 × 60 m plots to quantify the structure of living and dead tree community, including a set of old-growth attributes connected to large trees, deadwood, and established regeneration. In each plot, we measured the abundance of all orchid species and explored their behaviour according to the trophic strategy (autotrophy/mixotrophy, obligate mycoheterotrophy), rarity within the NP, and threatened status according to the IUCN Red List. We used multivariate ordination and classification techniques to assess plot similarities according to forest structure and Orchid Community and identify the main structural factors related to orchid features. The main structural factors were used as predictors of community traits. Forest composition (i.e., the dominance/abundance of silver fir) affected the presence of the main orchid genera: Epipactis were abundant in silver fir-dominated forests, Cephalanthera in mixed beech and fir forests. Interestingly, Cephalanthera could become limited even in beech-dominated conditions if fir regeneration was abundant and established. Old-growth attributes like the density of deadwood and large tree volume were important determinants of the presence of rare and mycoheterotrophic species. Our results provided a first quantitative description of forest reference conditions to be used in the protection and restoration of threatened and rare orchid species. Full article

Epiphytic bryophytes are an important component in terms of the diversity and functioning of montane forests known as biodiversity hotspots. Bryophytes are highly dependent on their external environments because they are sensitive to environmental changes related to disturbance, fragmentation, air pollution, and climate change. The richness and composition of bryophytes in remnants of primary and secondary forests were analyzed, where the richness and cover were recorded on trunk bases of 120 trees. Changes in species richness and diversity were analyzed using generalized linear models (GLMs), and changes in species composition, using multivariate analysis. A total of 57 bryophyte species (36 liverworts and 21 mosses) were recorded in trunk bases. For the first time, 19 new liverworts for the province of El Oro are reported. The richness and diversity of bryophyte species decrease in disturbed forests when compared to primary forests, with a marked decrease in species less adapted to conditions of high light (shade epiphytes). In the same line, species composition is different in each type of forest, where bryophytes with high humidity requirements were abundant in primary forests. This study confirms that forest disturbance is a key factor in determining not only the number of species but also the composition of bryophyte species. The maximum tree diameter and primary forest remnants are important factors in the conservation of sensitive bryophyte species at the base of trees in one of the last remnants of mountain forests in El Oro Province, Ecuador. Full article

Soil fungal communities are critical for forest ecosystem functions in the Central Hardwood Region (CHR) of the USA. This evaluation, which took place in 2022–2023, investigates the influence of Juglans nigra (BW, black walnut) and Quercus rubra (NRO, Northern red oak) on soil properties and fungal community structures across three CHR sites. The objectives of this study are to investigate how the fungal communities identified beneath J. nigra and Q. rubra serve to influence biodiversity and soil health within hardwood plantations. Soils from two locations in Indiana and one in Michigan were examined and assessed for variations in fungal composition and diversity. Soil fungal communities were characterized using Illumina high-throughput sequencing while multivariate analysis was applied to analyze patterns in these fungal communities. These data provided insights into how environment, location, and tree species affect fungal community structure. Results indicate that J. nigra soils exhibited higher carbon (0.36%, 1.02%, 0.72%), nitrogen (25%, 29%, 56%), and pH (0.46, 1.08, 1.54) levels than Q. rubra soils across all three sites and foster greater fungal diversity. Specifically, J. nigra was associated with increased Ascomycota diversity, whereas Q. rubra supported a higher prevalence of Basidiomycota. Basidiomycota were negatively correlated with carbon and pH, while Ascomycota showed positive correlations with these variables. These findings highlight how crucial it is to understand how different tree species influence fungal communities and, consequently, how they influence forest soil health. Our findings serve to improve forest management practices by emphasizing the importance of fungal communities in maintaining the function and resilience of an ecosystem. Our study underscores that grasping these specific interactions is essential for effective forest management, especially when considering how to use fungal communities to boost plant growth. This work focuses on hardwood plantations rather than either agricultural ecosystems, monocultures, or native forests, thus filling a gap in the current literature where many studies are limited to specific fungal groups such as mycorrhizae. In future research, it is important to examine a wider range of tree species. This will deepen our understanding of fungal community dynamics and their impact on maintaining healthy forest ecosystems. Our hardwood plantation focus also notes the potential for adaptive forest management as environmental conditions change. Full article

Tidal freshwater forested wetlands (TFFWs) typically occur at the interface between upriver non-tidal forests and downstream tidal marshes. Due to their location, these forests are susceptible to estuarine and riverine influences, notably periodic saltwater intrusion events. The Mobile-Tensaw (MT) River Delta, one of the largest river deltas in the United States, features TFFWs that are understudied but threatened by sea level rise and human impacts. We surveyed 47 TFFW stands across a tidal gradient previously determined using nine stations to collect continuous water level and salinity data. Forest data were collected from 400 m² circular plots of canopy and midstory species composition, canopy tree diameter and basal area, stem density, and tree condition. Multivariate hierarchical clustering identified five distinct canopy communities (p = 0.001): Mixed Forest, Swamp Tupelo, Water Tupelo, Bald Cypress, and Bald Cypress and Mixed Tupelo. Environmental factors, such as river distance (p = 0.001) and plot elevation (p = 0.06), were related to community composition. Similar to other TFFWs along the northern Gulf of Mexico, forests closest to Mobile Bay exhibited lower basal areas, species density, diversity, and a higher proportion of visually stressed individual canopy trees compared to those in the upper tidal reach. Results indicate a strong tidal influence on forest composition, structure, and community-level responses. Full article