Forest Tree Species Research Articles

Determination of land surface temperatures for some oak stands with Landsat 8 OLI satellite images: a case study from Turkey.

This study investigates the effect of forest cover, development stage and aspect factors on surface temperature (LST) in Demirköy and Düzce Forest Enterprises (FE) using Landsat 8 OLI satellite imagery from July 2021. In Demirköy FE, the highest LST value was recorded in the district center with 47.4 °C, in Düzce FE, the highest LST value was recorded in the provincial center with 44.6 °C, while the lowest value was 14.3°C in Demirköy FE and 13.02 °C in Düzce FE in densely forested areas. When the stands were evaluated, it was found that pure juvenile oak stands had the highest average LST value with 30.48 °C in Demirköy FE and 23.96 °C in Düzce FE, whereas lower LST values were observed in old oak stands due to more dense cover. In terms of aspect, higher temperatures were recorded in the southern and western aspects in both study areas. In Düzce FE, high LST values were also observed in juvenile stands in the northern direction, indicating the influence of local factors such as topography and solar radiation angle. The highest LST values were observed in open forest areas; 6-9 °C higher temperatures were found in Demirköy and 1-5 °C higher in Düzce compared to vegetated areas. Significant correlations were found between LST and vegetation indices, and the highest correlation was found between LST and Normalized Difference Structuring Index (NDBI) (R2, 0.54 in Demirköy and R2, 0.50 in Düzce). NDVI showed a negative relationship with LST (R2, 0.47 in Demirköy, R2, 0.43 in Düzce). These findings reveal the critical role of forest density, tree species, and forest management practices in regulating surface temperatures, especially in the context of urbanization and deforestation.

Long-term surveys of ungulates' effects on tree and shrub species in mountainous forests -outcomes and potential limits.

Ungulate herbivory might induce different effects on the diversity and growth of trees and shrubs. The density, distribution, and the species of ungulates as well as plant communities' composition and other factors determine whether ungulate herbivory promotes or limits plants' diversity and growth. The impacts of ungulates on woody plants are commonly surveyed with exclosure-control approaches. In practice, such surveys frequently only cover short periods of time, addressing immediate management needs. Long-term surveys, documenting lasting effects of ungulate herbivory, are highly needed, but still rare. However, the general transferability of outcomes of long-term surveys might be limited due to different disturbing factors. This study addresses two basic aspects of long-term monitoring in mountainous forests, based on a unique 30-year data set: (1) Possible long-term effects of herbivores on forest vegetation (e.g., species/structural diversity of woody plants) and (2) potential differences between short-term and long-term surveys in terms of height growth patterns. In our study, diversity of woody plant species showed great variability with no significant impact of ungulate herbivory. The presence of ungulates had a significantly negative effect on the vertical structural diversity and growth of trees. Due to the slower growth on control plots, it took trees longer to reach a 160 cm height-threshold with their terminal shoots than on exclosure plots. Our long-term control-exclosure data set indicated that long-term survey data indeed might differ from growth patterns represented by short-term surveys. This can be induced by several factors, like site-specific growth patterns of trees, occurrences of natural abiotic disturbances that influence the functional life of exclosures, and others.

Specificity determinants of pathogens in forest

Abstract Host‐specific pathogens have long been suggested to act as a major driver of species diversity in tropical forests. However, determining the degree of host specificity of potential pathogens coupled to key cellular characteristics of infection is difficult and time‐consuming. These challenges have delayed progress in relating the functional specificity of pathogenic fungi to ecological consequences. We tested the pathogenicity of 27 (of 215) fungi that were isolated from surface sterilized roots of seedlings from four common tree species in a diverse subtropical forest. Inoculation experiments showed that six fungi exhibited strong pathogenicity on the host seedlings. Five of these only infected their specific hosts (i.e. host‐specific pathogen species). Green fluorescent protein labelling revealed that in three host‐specific pathogens fungal hyphae were able to grow into the vascular tissues only in their specific host plant, in contrast to other fungal‐host combinations that exhibit non‐pathogenic interactions. This fluorescent labelling technique allows direct tracking of the progress of fungal infection in different host tissues. Synthesis. By coupling the green fluorescent protein technique with standard host inoculation experiments, we determined the developmental differences between infections by pathogenic and non‐pathogenic fungi in a relatively simple and straightforward way. Our work provides a useful tool for rapidly screening and categorizing host–fungal interactions, reflecting the functional basis of host specificity of pathogenic fungi. More broadly, this technique can contribute to understanding the roles of pathogens in species coexistence and biodiversity maintenance in forest communities.

The complete mitochondrial genome of Castanopsis carlesii and Castanea henryi reveals the rearrangement and size differences of mitochondrial DNA molecules

BackgroundCastanopsis carlesii is a dominant tree species in subtropical evergreen broad-leaved forests and holds significant ecological value. It serves as an excellent timber tree species and raw material for cultivating edible fungi. Henry Chinquapin (Castanea henryi) wood is known for its hardness and resistance to water and moisture, making it an exceptional timber species. Additionally, its fruit has a sweet and fruity taste, making it a valuable food source. However, the mitogenomes of these species have not been previously reported. To gain a better understanding of them, this study successfully assembled high-quality mitogenomes of C. carlesii and Ca. henryi for the first time.ResultsOur research reveals that the mitochondrial DNA (mtDNA) of C. carlesii exhibits a unique multi-branched conformation, while Ca. henryi primarily exists in the form of two independent molecules that can be further divided into three independent molecules through one pair of long repetitive sequences. The size of the mitogenomes of C. carlesii and Ca. henryi are 592,702 bp and 379,929 bp respectively, which are currently the largest and smallest Fagaceae mitogenomes recorded thus far. The primary factor influencing mitogenome size is dispersed repeats. Comparison with published mitogenomes from closely related species highlights differences in size, gene loss patterns, codon usage preferences, repetitive sequences, as well as mitochondrial plastid DNA segments (MTPTs).ConclusionsOur study enhances the understanding of mitogenome structure and evolution in Fagaceae, laying a crucial foundation for future research on cell respiration, disease resistance, and other traits in this family.

Forest tree extracts induce resistance to Pseudomonas syringae pv. tomato in Arabidopsis.

The widespread use of conventional pesticides for plant pathogen control poses significant risks to human health and the environment, and it is therefore crucial to develop environmentally friendly, human-safe alternatives to these products that offer a sustainable approach for crop protection. Here, we examined the potential of ethanolic extracts from four forest tree species for their antibacterial activity against the bacterial pathogenPseudomonas syringaepv.tomato (Pst) and their ability to trigger effective defense responses in the model plantArabidopsis thaliana. The extracts exhibited direct toxic effects against Pst and triggered the expression of defense-related genes naturally induced by oxidative stress cues or the defense elicitor salicylic acid in leaf tissue. The direct antibacterial effects of the tree extracts, together with their defense gene-inducing effectsin planta, resulted in a strong host plant-protecting effect againstPst. These findings suggest the eventual effectiveness of forest tree extracts as plant protectants against the bacterial pathogenPst. They also suggest the potential of these extracts as a sustainable, eco-friendly alternative to conventional pesticides for the management of economically important plant pathogens.

Resilience of genetic diversity in forest trees over the Quaternary

The effect of past environmental changes on the demography and genetic diversity of natural populations remains a contentious issue and has rarely been investigated across multiple, phylogenetically distant species. Here, we perform comparative population genomic analyses and demographic inferences for seven widely distributed and ecologically contrasting European forest tree species based on concerted sampling of 164 populations across their natural ranges. For all seven species, the effective population size, Ne, increased or remained stable over many glacial cycles and up to 15 million years in the most extreme cases. Surprisingly, the drastic environmental changes associated with the Pleistocene glacial cycles have had little impact on the level of genetic diversity of dominant forest tree species, despite major shifts in their geographic ranges. Based on their trajectories of Ne over time, the seven tree species can be divided into three major groups, highlighting the importance of life history and range size in determining synchronous variation in genetic diversity over time. Altogether, our results indicate that forest trees have been able to retain their evolutionary potential over very long periods of time despite strong environmental changes.

Metabolome and Transcriptome Combined Reveal the Main Floral Volatile Compounds and Key Regulatory Genes of Castanea mollissima.

Chestnut (Castanea mollissima) is an economically important forest tree species, and its flowers possess functions such as repelling mosquitoes, killing bacteria, and clearing heat. However, the regulatory mechanisms of floral volatile organic compounds (VOCs) in chestnut are still unclear. This study analyzed the contents of major volatile compounds and related gene expression levels in chestnut flowers during the initial flowering stage (IFS) and full-flowering stage (FFS) using metabolomics and transcription techniques. In total, 926 volatile compounds were detected, mainly terpenes, heterocyclic compounds, and esters. Acetylenone, styrene, and β-pinene had contents that exceeded 5% in FFS chestnut flowers. In total, 325 differential metabolites between the IFS and FFS were significantly (p < 0.05) enriched in the biosynthetic pathways of sesquiterpenes and triterpenes, as well as the ethylbenzene metabolic pathway. In total, 31 differentially expressed genes (DEGs) were related to terpenoid biosynthesis. There were only two DEGs related to the ethylbenzene metabolic pathway. In summary, we identified the volatile components of chestnut flowers and analyzed the changes in the contents of major volatile compounds in the flowers and the expression patterns of the related genes. The research results are helpful for understanding the regulation of VOCs in chestnut flowers.

Climatic Effects on the Growth of Fagus sylvatica L. in Mixed Stands with Pinus sylvestris L. in Lithuania

Climate change and warming will potentially profoundly affect forest growth and yield. However, climate change is not only a threat but also an opportunity for tree species to be more productive or colonize new territories where previously they were fragmented or absent. European beech (Fagus sylvatica L.) is a dominant and significant tree species in European forests with a pronounced ability to grow on a great variety of sites and to form mixtures with other tree species due to its shade tolerance. So far, only a few studies have analysed its growth and reaction to changing climatic conditions outside its natural gradient in the north. The aim of this study was therefore to clarify the main growth patterns and tree ring formation characteristics of beech (outside their natural distribution) in mixed stands with Scots pine (Pinus sylvestris L.) The analyses were carried out in two-layered stands in the western part of Lithuania with tree-ring data measured on stem disks collected at 1 m height that were available from shelter-cut thinning activities in a number of forest stands in the region. Our results show that higher temperatures during the summer months of July and August generally inhibited the radial growth of beech under given site conditions. In contrast, warmer late-autumn and cooler early-winter periods together with warmer springs positively affected the radial increments. Above-average precipitation during the vegetation period contributed to the beech producing additional amounts of radial increments. The increasing temperature trends of the summer months and decreasing monthly amounts of precipitation during the vegetation period in recent decades tend to have adverse effects on the ecological conditions for beech growth and vitality in Lithuania. Despite these results, the European beech successfully grows in the sample region and has produced 200 m3 ha−1 in the analysed stands.

Traits associated with the conservation gradient are the strongest predictors of early‐stage fine root decomposition rates

Abstract Fine root traits span two independent axes of variation, the conservation and collaboration axes, which define the root economic space (RES). However, whether early‐stage fine root decomposition rates (quantified as proportion mass loss, i.e. pml) are more strongly related to collaboration or conservation traits remains unclear. We studied 63 tree species in New Zealand's temperate rain forest. We determined the phylogenetic signal in pml and fine root traits, conducted phylogenetic principal component analysis and used phylogenetic generalized least squares to determine which traits are most strongly related to pml. Root decomposition exhibited a high phylogenetic signal and was more strongly related to the conservation than the collaboration axis. Root tissue density (RTD) was negatively correlated and root nitrogen (RN) was positively correlated with pml. Root diameter was positively yet weakly correlated with pml, but specific root length was uncorrelated with pml. The lignin‐to‐N ratio and root cellulose were the strongest predictors of pml. Synthesis: Early‐stage fine root decomposition is most strongly driven by tissue quality traits, such as root nitrogen, tissue density and lignin‐to‐N ratio, which all align with the conservation axis of the root economics space. However, root diameter plays a weak yet undeniable role in early‐stage fine root decomposition. Some thick‐rooted species decomposed faster, possibly due to the higher quality cortical tissue. Thin‐rooted species decomposed slower, possibly because of their higher cellulose concentration that maintains the structural integrity of small diameter roots. Relationships between decomposition and other traits that align with the collaboration gradient deserve further study across the phylogeny of vascular plants.

Genomic variation of European beech reveals signals of local adaptation despite high levels of phenotypic plasticity

Local adaptation is key for ecotypic differentiation and species evolution. Understanding underlying genomic patterns can allow the prediction of future maladaptation and ecosystem stability. Here, we report the whole-genome resequencing of 874 individuals from 100 range-wide populations of European beech (Fagus sylvatica L.), an important forest tree species in Europe. We show that genetic variation closely mirrors geography with a clear pattern of isolation-by-distance. Genome-wide analyses for genotype-environment associations (GEAs) identify relatively few potentially adaptive variants after correcting for an overwhelming signal of statistically significant but non-causal GEAs. We characterize the single high confidence genomic region and pinpoint a candidate gene possibly involved in winter temperature adaptation via modulation of spring phenology. Surprisingly, allelic variation at this locus does not result in any apparent fitness differences in a common garden. More generally, reciprocal transplant experiments across large climate distances suggest extensive phenotypic plasticity. Nevertheless, we find indications of polygenic adaptation which may be essential in natural ecosystems. This polygenic signal exhibits broad- and fine-scale variation across the landscape, highlighting the relevance of spatial resolution. In summary, our results emphasize the importance, but also exemplify the complexity, of employing natural genetic variation for forest conservation under climate change.

Flowering and Fruiting Phenology of Selected Indigenous Tree Species in Anferara Natural Forests, Southern Ethiopia

Flowering and Fruiting Phenology of Selected Indigenous Tree Species in Anferara Natural Forests, Southern Ethiopia

1110. Hibiscus glaber Matsum. ex Nakai: Malvaceae

SummaryHibiscus glaber is a symbolically significant endemic species found exclusively on the Ogasawara (Bonin) Islands. It is one of the main tree species in the natural forests of the island. This species is illustrated here, and its natural history, ecology, pollination, and cultivation are described.

Revealing suitable habitats for Juniperus procera and Olea europaea tree species in the remnant dry Afromontane forests of Ethiopia: Insights from ensemble species distribution modeling approach.

Human activities and climate change pose a significant threat to the dry Afromontane forests in Ethiopia, which are essential for millions of people both economically and ecologically. In Ethiopia, trees are planted elsewhere even if they are not likely to be well suited to the area. This study aims to identify the suitable habitat for the most exploited Juniperus procera (J. procera) and Olea europaea (O. europaea) tree species in northern Ethiopia. As inputs, least correlated temperature, moisture, soil, and topographic variables were selected through a stepwise procedure. The study evaluated five individual and ensemble models using the area under the curve (AUC) and true skill statistic (TSS) values. The ensemble model outperformed with mean AUC of 0.95 and TSS of 0.78 for J. procera, while securing the second position for O. europaea with an AUC of 0.88 and TSS of 0.71. Climatic factors emerged as the most influential, followed by soil and topography. Suitable areas for both species were found when Isothermality (Bio3) values range from 52% to 62%, temperature seasonality (Bio4) of 16-29°C. Moreover, well drained soils with soil texture not heavier than sandy clay, and soil organic carbon ranging from 5 to 42 g kg-1 were found suitable. The optimal suitable altitude for J. procera and O. europaea was determined to be 2200-2600 and 2100-2500 m.a.s.l., respectively. The suitable areas for J. procera and O. europaea were estimated to be 3130 and 3946 km2, respectively. Furthermore, potential plantation areas were identified beyond Desa'a and Hugumbirda Grat-Kahsu protected forests, covering 2721 km2 (86.9%) for J. procera and 3576 km2 (90.6%) for O. europaea. These findings hold significance for the conservation and sustainable management of these valuable tree species in northern Ethiopia. We recommend implementing a similar approach for other locally restricted dry Afromontane tree species with wider potential distribution.

Mapping forest tree species and its biodiversity using EnMAP hyperspectral data along with Sentinel-2 temporal data: An approach of tree species classification and diversity indices

Forests play a crucial role in maintaining ecological balance and biodiversity, making the accurate mapping of tree species and assessment of biodiversity indices essential for informed management decisions. This study introduces an innovative methodology that integrates EnMAP (Environmental Mapping and Analysis Program) hyperspectral data with Sentinel-2 multitemporal data to classify tree species in the biodiverse landscapes of Kampinos National Park and its surrounding regions in Poland.We extract essential vegetation indices such as NDVI, NDMI, SAVI, and EVI from Sentinel-2 data to assess forest health and dynamics. The Sentinel-2 data is upscaled from 10 m to 30 m to align with EnMAP’s spatial resolution, followed by precise co-registration of the images using QGIS. Utilizing a rich dataset from the National Forest Inventory, we extract spectral signatures of nine distinct tree species from both data sources. We employ five machine learning algorithms—Support Vector Machines (SVM), Random Forest (RF), CatBoost (CAT), Gradient Boosting Classifier (GBC), and XGBoost (XGB)—to enhance classification accuracy.Through iterative experimentation with data reduction techniques and algorithm tuning, we achieve optimal performance across needle-leaved and broad-leaved species. The resulting tree species maps are validated through quantitative accuracy assessments against mixed-species polygons from the National Forest Inventory and ground truthing in the Kampinos National Park. Achieving an overall accuracy of 85% to 93%, our study demonstrates the efficacy of this integrated approach in tree species mapping. Furthermore, the tree species maps serve as a foundation for deriving key biodiversity indices—species richness, Shannon-Wiener Diversity Index, Simpson’s Diversity Index, and a composite Biodiversity Index—providing insights into spatial biodiversity patterns and informing targeted conservation strategies. This study exemplifies the potential of combining advanced remote sensing techniques with field validation to enhance our understanding of forest ecosystems and guide sustainable management practices.

Phylogenetic structure and turnover between lowland and montane subtropical forests indicate differential community assembly processes, affected by successional stage and spatial gradients

Secondary forests represent an increasing proportion of global forest cover and offer a range of ecosystem services that are integral to environmental policy targets. Highly disturbed landscapes with temporal records of forest plant community composition offer key insights into the processes that shape plant communities as forests undergo secondary succession. We investigated patterns of plant community phylogenetic structure and phylogenetic beta diversity. Mean pairwise distance (MPD) and Mean Nearest Taxon Distance (MNTD) metrics were determined between co-occurring species within plant communities, in addition to phylogenetic beta diversity metrics relative to null models of random phylogenetic assembly. MPD and MNTD were compared between elevational and successional classes and modelled as products of intercommunity distance (metres) and forest community age (years). Phylogenetic nonmetric multidimensional scaling explored phylogenetic community structure between lowland and montane forest type in Hong Kong. We found that plant communities in secondary forests in Hong Kong exhibited patterns of increased basal phylogenetic clustering with increasing community elevation, while phylogenetic turnover was influenced by spatial and successional factors in lowland and montane forest. Our findings indicate differential community assembly in lowland compared to montane forest type in Hong Kong, as well as evidence for barriers to plant dispersal in secondary forest communities due to patterns of spatial phylogenetic clustering. Plant communities in montane forests were found to be phylogenetically distinct from lowland forest plant communities. Patterns of spatial phylogenetic clustering may suggest significant dispersal or post-dispersal processes causing the clustering of related species at fine spatial scales, while phylogenetic turnover with increasing successional age may indicate compositional changes during the process of passive forest regeneration. Collectively, these results emphasize the need to investigate active pathways for rewilding dispersal limited late successional forest tree species in Hong Kong.

Impacts of phosphite treatment on Phytophthora community assemblages and inoculum abundances in Phytophthora-infected forest soil

Phytophthora are causing declines in forest tree species worldwide and the chemical control treatment, phosphite, is the only treatment consistently shown to provide some protection to natural ecosystems from Phytophthora diseases. Phosphite inhibits Phytophthora growth and sporulation whilst boosting defence responses in the plant host. It is unclear, however, the extent of the impact of phosphite on Phytophthora species assemblages and inoculum abundances in soil around trees following treatment within natural ecosystems. In New Zealand, kauri (Agathis australis), an endemic and threatened foundation species, suffers from a dieback disease primarily caused by Phytophthora agathidicida. Phosphite is applied by trunk injection to kauri and has been shown to improve resin ‘bleed’ symptoms from basal trunk lesions and to promote recovery of thinned canopies. Phytophthora community and inoculum abundance were investigated in response to phosphite treatments at two field sites (Huia and Waitoki) in infected kauri stands in Auckland, New Zealand. At Huia, soil sampling and tree health surveying were conducted in November 2023 on trees treated with phosphite in 2012 as part of an earlier study. At Waitoki, the response to phosphite treatment was monitored 6 and 18 months following treatment. Phytophthora species were detected using soil baiting and metabarcoding of environmental DNA (eDNA) from soil and quantified with qPCR of root and soil DNA. Three species were detected with soil baiting (P. agathidicida, P. cinnamomi, and P. multivora) and two additional species with metabarcoding (P. pseudocryptogea, and an unknown clade 7 species similar to P. europaea). Phytophthora cinnamomi was the most abundant species, followed by P. agathidicida. Both species were more likely to occur together than by chance alone and were associated with declining tree health. The P. europaea-like species was in approximately 50% of the samples and was less likely to occur in roots with poorer health, or in association with P. agathidicida. The abundance of P. agathidicida inoculum was lower in the soil around the phosphite-treated trees than around the untreated control trees 1.5 years after treatment at Waitoki. Phosphite halted the lateral expansion of basal resin bleeds, and resin viscosity was reduced. Not only did phosphite treatments improve kauri dieback symptoms, but the phosphite treatments potentially had a direct impact on the epidemiology of the disease by reducing inoculum load around treated trees, with direct implications for disease management as an effective way to protect uninfected areas and minimise the spread of inoculum from infested zones.

How dominant height responds to mixing species: Effect of traits and height difference between species

Adapting forests to climate change is a major challenge for forest ecology and forestry. Among the management options available, encouraging the use of mixtures is a promising way forward. However, this practice requires a thorough understanding of how species respond to mixing. In this article, we analyzed species dominant height responds to mixing and how species ontogeny and traits drive this response. We compared species observed dominant height in mixed even-aged stands with the expected dominant height of the same species in a monospecific stand under the same environmental conditions. We then related this dominant height variation due to mixing to between-species dominant height difference and to species traits linked to competition (shade tolerance, wood density, specific leaf area).We focused our analyses on 76 pairs of forest tree species. We used data from the French National Forest Inventory to calculate species dominant height in 1368 mixed stands. We then used previously developed models to estimate the expected dominant height in virtual monospecific stands with the same environmental conditions.We found that mixture had a significant impact on species dominant height for 15 out of 50 species-combination considered. Dominant height of a given species was higher in mixture than in pure stands when this species had a lower dominant height in pure stands, a lower shade tolerance, a lower specific leaf area or a higher wood density than its companion species.Our results suggest that species dominant height response to mixing depends on how mixture influences the competition for light. Our results will help inform strategies aiming to diversify species in forests, and will be especially useful in anticipating a given species’ behavior in response to competition for light when it is mixed with other species.

Silicon Modifies Photosynthesis Efficiency and hsp Gene Expression in European Beech (Fagus sylvatica) Seedlings Exposed to Drought Stress.

Background: Climate change is leading to severe and long-term droughts in European forest ecosystems. can have profound effects on various physiological processes, including photosynthesis, gene expression patterns, and nutrient uptake at the developmental stage of young trees. Objectives: Our study aimed to test the hypothesis that the application of silica (SiO2) influences photosynthetic efficiency and gene expression in 1- to 2-year-old Fagus sylvatica (L.) seedlings. Additionally, we aimed to assess whether silicon application positively influences the structural properties of leaves and roots. To determine whether the plant physiological responses are genotype-specific, seedlings of four geographically different provenances were subjected to a one-year evaluation under greenhouse conditions. Methods: We used the Kruskal-Wallis test followed by Wilcoxon's test to evaluate the differences in silicon content and ANOVA followed by Tukey's test to evaluate the physiological responses of seedlings depending on treatment and provenance. Results: Our results showed a significantly higher Si content in the roots compared with the leaves, regardless of provenance and treatment. The most significant differences in photosynthetic performance were found in trees exposed to Si treatment, but the physiological responses were generally nuanced and provenance-dependent. Expression of hsp70 and hsp90 was also increased in leaf tissues of all provenances. These results provide practical insights that Si can improve the overall health and resilience of beech seedlings in nursery and forest ecosystems, with possible differences in the beneficial role of silicon application arising from the large differences in wild populations of forest tree species.

Genomic diversity of major tree species in the Eurasian relict forests of northern Iran

We investigated population genetics of the native tree species Acer velutinum Boiss., Fagus orientalis Lipsky, and Quercus castaneifolia C.A. Mey. in the Hyrcanian forests of northern Iran and also F. orientalis populations in the Euro-Siberian and Colchic subregions of northern Türkiye. We used the double-digest RADseq method and genotyped 90 populations and 1,589 individuals across the distribution range of the species. Genome-wide SNPs from 28 populations of A. velutinum, 32 populations of F. orientalis, and 30 Q. castaneifolia revealed higher genetic differentiation among A. velutinum populations than among F. orientalis and Q. castaneifolia. The global FST value was lowest for F. orientalis populations and highest for A. velutinum populations, while the global FIS value was negative for A. velutinum. Demographic history analysis revealed a bottleneck during the last glacial period (11,500—115,000 Kya) for the A. velutinum populations with reduced effective population size (Ne). All three species show multiple bottlenecks and reduced Ne during the Quaternary. Pronounced genetic divergence among A. velutinum populations in the Hyrcanian forests compared to the other two species suggests cryptic speciation. Conversely, F. orientalis and Q. castaneifolia populations showed low levels of genetic structure, suggesting that species-specific factors, such as pollen production and pollination efficiency, may have influenced the genetic patterns within these species in similar environments. The nucleotide diversity of F. orientalis populations in Iran is negatively correlated with altitude (p = 0.046). In contrast, A. velutinum populations show a significant correlation between nucleotide diversity and longitude (p = 0.008). Furthermore, the F. orientalis populations from Türkiye showed a distinct west–east genetic structure and were highly diverged from the Iranian F. orientalis populations.

Vegetation Structure, Composition and Plant Community types in Tropical Dry Deciduous Forests of Jaipur, Rajasthan, India

The research was carried out in the Aravalli Forests of Nahargarh (NWLS) and Jamwa Ramgarh Wildlife Sanctuaries (JRWLS) of Jaipur, Rajasthan, India. The vegetation structure, composition, biodiversity and plant community types were assessed across the five forest stands viz Nahargarh biological park (S1), Nahargarh Sanctuary (S2) in NWLS and Ramgarh (S3), Raisar (S4), and Digota (S5) of JRWLS, respectively. A total of 164 qaudrats of 20*20 m2 were laid to assess the vegetation data including frequency, basal area, density, importance value index (IVI), biodiversity indices (Shannon-weiner, Simpson, Pielou and Margalef’s) and plant community types. The tree basal area ranged between 18.56 -34.36 m2/ha while stand density was 923-1433 tree/ha. Our study indicated the dominance of family Fabaceae with 20 species and 11 genera with Anogeissus pendula showing the maximum frequency, density, mean basal area and IVI. Further, the agglomerative hierarchal clustering showed five types of plant communities with Anogeissus-Adhatoda as the most widely spread community in these forests. Among the two sanctuaries, species diversity was higher for JRWLS (2.83) than NWLS (2.80). The current study provides important baseline data for forthcoming research on monitoring and preserving these forest’s biological diversity. The significance of present study will provide insight into the structure and variety of tree species in tropical dry deciduous forests.