Population structure and regeneration status of Dalbergia latifolia Roxb. (Indian rosewood) in forest areas of Karnataka, India: implications for conservation and sustainable management

This study assessed the tree species diversity and their population structure in Chaudhary Charan Singh University of Meerut. A total of 19922 tree individuals (>10 cm girth) were measured for their girths at breast height. Girth-size distribution of trees in entire campus and that of dominant tree flora were separately analyzed to understand their growth and regeneration status. Physico-chemical characteristics of soils under dominant tree cover were also estimated. Spread over an area of 222 acres, the campus had 128 tree species distributed over 43 plant families. Leucaena leucocephala accounted for over 23.45% of total tree population, followed by Eucalyptus globulus (12.02%), Ficus benjamina (5.56%), Monoon longifolium (5.11%), Azadirachta indica (4.41%). However, they were not uniformly distributed. Eucalyptus globulus alone accounted for 42% of total campus area under tree cover (>490 m2) followed by Mangifera indica (5%), Azadirachta indica (4.9%), Alstonia scholaris (3.1%), and Leucaena leucocephala (3.1%). A single tree of Ceiba speciosa exhibited a basal cover of 3539 cm2. Largest tree population (9303) occurred in girth range 10-30 cm. Ficus benghalensis recorded highest girth (693 cm). Eucalyptus globulus showed declining population (77% in 50-150 cm) in contrast to expanding populations of Monoon longifolium, Albizia lebbeck, and stable populations of Holoptelea integrifolia, Dalbergia sissoo and Azadirachta indica. Soil organic carbon ranged 0.33 – 1.1% and C:N ratio 4.5 – 14.3 in soils under different species cover, indicative of specific tree cover impact. Besides implication for conservation and commercial exploitation of planted trees in this university-campus, study has projected implication for potential carbon sink and sequestration.

Background Dalbergia latifolia(Indian Rosewood), a species of both ecological and economic importance, faces growing threats from habitat degradation, deforestation, and illegal logging. Given its critical role in maintaining ecosystem services and its commercial value, understanding its habitat distribution is vital for developing effective conservation strategies. This study employs the MaxEnt (Maximum Entropy) modeling approach to assess the species' habitat suitability across tropical and subtropical regions of India, which represent its primary distribution range. The results have broader implications for conservation efforts and sustainable management practices. Results The MaxEnt model highlights tropical dry and moist deciduous forests as the most suitable habitats for D. latifolia. The species prefers specific climatic conditions, particularly temperature and precipitation ranges, which were identified as key determinants of its distribution. High-suitability areas were found in Karnataka, Maharashtra, and Madhya Pradesh, characterized by warm climates and moderate rainfall. The model demonstrated robust performance, with the Area Under Curve (AUC) metric validating its predictions. Sensitivity analysis revealed that temperature and precipitation were the most influential environmental factors driving the species' distribution. Conclusions These findings offer critical insights for conservation strategies aimed at protecting D. latifolia from further habitat loss. Identifying regions with high habitat suitability allows for targeted conservation efforts, focusing on areas most at risk from anthropogenic pressures. This study provides a valuable framework for guiding forest management practices in India, with potential applications for similar species globally. The approach can be extended to assess the habitat suitability of other ecologically and economically significant species, contributing to international biodiversity conservation efforts.

Protected forests in Central Kalimantan are vital reservoirs of biodiversity, housing diverse flora and fauna crucial for local and global ecosystems. Despite their ecological significance, these forests face imminent threats from deforestation, illegal encroachment, and climate change, jeopardizing their biodiversity and ecological integrity. This study aims to assess the biodiversity of Central Kalimantan's protected forests and explore its implications for conservation and sustainable management. The research methodology employs a comprehensive approach, integrating field surveys, laboratory analysis, and community engagement. Field surveys involve transect walks, camera traps, and direct observations to inventory flora and fauna. Soil and water analyses assess habitat conditions, while participatory approaches engage local communities in forest management. Findings reveal a rich diversity of flora and fauna, including rare and endemic species such as Shorea stenoptera and Dipterocarpus grandiflorus. High Shannon-Wiener and Simpson diversity indices indicate a healthy ecosystem, but deforestation and illegal encroachment pose significant threats, fragmenting habitats and disrupting species survival. Climate change exacerbates these challenges, necessitating adaptation strategies for ecosystem resilience. Community participation emerges as pivotal in conservation efforts, leveraging traditional knowledge and fostering sustainable livelihoods. Collaboration among stakeholders is essential for effective forest management, emphasizing the need for holistic conservation strategies. In conclusion, this study underscores the urgent need for conservation action to safeguard the biodiversity of Central Kalimantan's protected forests. By integrating scientific research with community engagement, policymakers and stakeholders can develop effective strategies to conserve these invaluable ecosystems, ensuring their sustainability for future generations.

Distribution pattern, population structure and habitat geography of Betula utilis subalpine forests of Kashmir region in the western Himalayas: implications for conservation and sustainable management

The floristic composition of Sal forests is paramount for biodiversity and environmental resilience. Monitoring species diversity contributes to conservation and sustainable management. Considering this, the present study was undertaken to assess the floristic composition and diversity of Shorea robusta-dominated stands in the Paonta Forest Range of Himachal Pradesh. Sample plots of 0.1 ha were laid out (systematic random sampling) in seven compartments, recording 33 genera with 34 species belonging to 26 families. The results revealed that the flora of compartments catalogued with Lai C28 had the maximum (9) tree species, Kukron C15 and Rajban C10 had the maximum shrub species, and Rajban C6 and Rajban C7 had maximum herb species among all the compartments. S. robusta was the dominant species, with IVI varying between 126.72 and 156.59 in the compartments. The similarity index of trees in compartments ranged from 0.67 to 1.00. Rajban C6 and Rajban C7 had the maximum similarity index. This research focused on documenting the diversity of plants within the Sal Forest of Himachal Pradesh, India, and produced valuable scientific data and a fundamental understanding for the conservation of biodiversity and sustainable management.

Aspen demographics in relation to spatial context and ungulate browsing: Implications for conservation and forest management

In Dalbergia latifolia Roxb. (Indian rosewood), a premium-quality vulnerable timber tree species belonging to Family Fabaceae, direct somatic embryogenesis was achieved. Immature cotyledons from green pods were collected from trees at 90 d after flowering and somatic embryo formation was achieved on Murashige and Skoog’s medium supplemented with 0.5 mg L−1 2,4-dichlorophenoxyacetic acid and 0.1 mg L−1 kinetin. Different developmental stages, ranging from globular, heart-shaped, torpedo, and cotyledonary stage, were recorded during the complete formation of somatic embryos. Globular somatic embryos gradually converted into heart shape after 35 to 40 d, torpedo shape after 50 to 55 d, and dicotyledonary-shaped embryos after 60 d of culture. The individual isolated somatic embryos with well-developed cotyledons were transferred on medium containing 0.5 mg L−1 benzyl adenine and 0.1 mg L−1 abscisic acid to promote development into plantlets. Biochemical changes in soluble sugars, total carbohydrates, phenols, and nitrate reductase activity were monitored at 5-d intervals from 0 to 60 d. Soluble sugar content (%) increased from 5.26% to 28.05% during the culture period. Minimum sugar content was noted in the globular stage, followed by heart-shaped and torpedo stage and maximum sugar content was observed in cotyledonary somatic embryo stage. A similar trend was observed in total carbohydrate content also (12.83% to 41.23%). A significant variation in the phenol content and nitrate reductase activity of the somatic embryos was observed and the peak values were achieved at 35 d in phenol content (4.25%) and 30 d in nitrate reductase activity (0.79 μmol NO2 h−1 g−1). Therefore, it was concluded that increasing levels of endogenous soluble sugar and carbohydrate play an important role during the formation of somatic embryos. These findings can be utilized to study the underlying carbohydrate and nitrogen metabolic pathways during somatic embryogenesis.

Australian hardwood species have potential in musical instrumentation replacing hardwood species such as Dalbergia latifolia (Indian rosewood- IRW) which is the main species used in guitar fretboard production. In this study, a detailed characterisation was conducted using dynamic and static testing to determine samples’ mechanical strength. Dynamic testing was conducted using non-destructive acoustic testing to record the sound velocity travelling through boards in the longitudinal grain direction. The elastic modulus for the tested samples was also calculated using the dynamic results. Four point bending tests were conducted in accordance with AS/NZS 4063.1 to determine the bending strength (MOR) and stiffness (MOE) to be compared with the dynamic results. The Janka hardness for each of the species was determined for reference in accordance with the Australian testing method developed by J.J. Mack. Species tested had sound radiation characteristics values close to Indian rosewood (IRW) samples tested. The internal friction of Australian samples tested and IRW were low providing indication for future applications of these species to musical instrument manufacture. Sound quality factor and speed of sound determined for tested species were similar to IRW. Mechanical strength and performance of the tested species displayed similar values to the IRW properties; indicating the potential of these species for long-term use in fretboard applications. The MOE and MOR values for Australian hardwood species were dependent on the density; the Queensland walnut (QWL), Kuranda Satin ash (KSA), Hickory ash (HKA) and Red mahogany (RMG) samples had highest mechanical strength values within the range of IRW including the Janka hardness, MOR and MOE values. The work presented here identified four Australian hardwood species with potential for fretboard production. These species will be tested for sound quality and performance prior to fretboard prototyping.

ContextThe intensification and expansion of human activities have caused profound changes in global wetlands and their associated aquatic bird communities. Understanding the mechanisms that drive the spatial assemblages of wetland birds is important for the development of effective conservation and management strategies.ObjectivesThe overall objective was to evaluate the influence of wetland features such as size and distance to the nearest coastline, and landscape composition, configuration, and function in shaping waterbird richness and abundance in 43 Tunisian Important Bird and Biodiversity Areas (IBAs).MethodsSystematic waterbird surveys on species abundance and richness at each IBA were carried out between December and January in 2020/2021 and 2021/2022. Satellite remote sensing indices were used to map wetlands and characterize the vegetation condition in the landscape surrounding them. Landscape metrics were used to describe the habitat configuration around the wetlands.ResultsOur results show that landscape composition, configuration and function have significant effects on waterbirds (i.e., shorebirds, waterfowl, wading birds, and open-water birds). We found that wetland surface area and distance to the coast were important factors influencing the richness and abundance of waterbirds. Our results also indicate that landscape diversity is an important predictor of waterbird richness and abundance, and that there is a significant interaction between wetland surface area and distance to the nearest wetland in explaining the richness and abundance of waterbirds.ConclusionsThis study provides evidence that the richness and abundance of waterbirds are robustly dependent on the interaction between wetland surface area and distance to the nearest wetland. Furthermore, local wetland characteristics (wetland surface area and distance to the nearest coastline), landscape composition (forest area and urban area), landscape configuration (spatial heterogeneity), and landscape function (maximum and minimum NDVI), significantly affect wintering waterbird communities. This study also highlights the importance of large and connected wetlands in conserving various bird communities in Tunisian IBAs and provides recommendations for their conservation and sustainable management.

We tested the hypothesis that dispersal is sex biased in an unexploited population of brook trout, Salvelinus fontinalis, on Cape Race, Newfoundland, Canada. Based on the assumptions that trout are promiscuous and that reproductive success is limited primarily by either number of mates (males) or fecundity (females), we predicted that males would disperse greater distances than females. We also tested the hypothesis that trout populations comprise stationary and mobile individuals, predicting that males have greater mobility than females. Based on a mark-recapture study of 943 individually tagged fishes, 191 of which were recaptured over 5 years, we find strong support for our hypothesis of male-biased dispersal in brook trout. Averaged among all 11 resampling periods, males dispersed 2.5 times as far as females; during the spawning period only, male dispersal exceeded that by females almost fourfold. Both sexes were heterogeneous with respect to movement, with a lower incidence of mobility among females (29.6%) than males (41.1%); mobile males dispersed six times further than mobile females. We conclude that this sex bias reduces mate competition among male kin and decreases the probability that males will reproduce with related females.

The dispersal and history of species affects their genetic population structure at both small and large geographical scales. The common whelk, Buccinum undatum, is a widespread subtidal gastropod in the North Atlantic that has no planktonic larvae and has thus limited dispersal capacity. The snail, which has been harvested by humans for centuries, is highly variable in morphology. To evaluate the population structure in the rich fishing grounds in western Iceland and its divergence from samples across the Atlantic, genetic patterns based on sequence variation in two mitochondrial (mt)DNA genes (COI and 16S) and five microsatellites were studied and compared with variation in populations from both sides of the Atlantic. Significant differences in allele and haplotype frequencies were found among samples separated by short distances along the coast of Iceland. Partition of the variation showed larger variance among samples obtained from distant regions than from neighbouring sites and genetic distances were correlated with geographical distance among populations in Europe. Phylogeographic patterns in mtDNA reveal different monophyletic lineages on both sides of the Atlantic, which predate the onset of the Ice Age and which may constitute cryptic species. Similar micro- and macrogeographical patterns were observed for the mtDNA and microsatellite markers, despite high frequencies of null alleles. Bayesian skyline reconstructions of the demographic history and mismatch distributions suggest that, although sizes of some populations were unaffected by Ice Age glaciations, others show signs of expansion after the Last Glacial Maximum. These phylogeographical patterns are consistent with patterns expected for low dispersal species that have survived in allopatric glacial refugial populations on both sides of the Atlantic and in deep-sea refugia within each continent. The observed genetic structure has implications for conservation and sustainable management of the harvested populations. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 111, 145–159.

Early life stages play a critical role in shaping recruitment dynamics and population structure in marine fishes, with implications for conservation and resource management. After declining in the 1950s, Atlantic halibut ( Hippoglossus hippoglossus (Linnaeus, 1758)) in the Gulf of St. Lawrence (GSL), Canada, has shown a marked comeback since the early 2000s, now ranking as the most valuable groundfish resource. Given its socio-economic importance, understanding larval ecology and early life stages is key to sustainable management. Spawning occurs in deep GSL channels and individuals exhibit summer site fidelity. Recently, otolith chemistry provided insights into lifetime movements and revealed three migratory contingents: annual migrants, irregular migrants, and residents. We analyzed the cores of 187 otoliths from halibut with known migration histories using laser ablation inductively coupled plasma mass spectrometry to quantify the number of nurseries and their contributions to the stock. To assess temporal trends, we examined four cohorts (2006, 2007, 2009, and 2010). Our findings suggest that Atlantic halibut in the GSL forms a philopatric population with multiple nurseries, and that natal origin does not influence later migration strategies. Given the role of early life stages in stock recruitment, these insights enhance our understanding of natal sources and support more informed management strategies.

Site-specific growth modeling based on tree-ring data is demonstrated to be an efficient tool for conservation and sustainable forest management of an economically important tropical tree species, Calophyllum brasiliense. One of the main challenges in the sustained management of natural tropical forests is obtaining reliable data on tree growth, which is prerequisite information for determining harvesting volumes and felling cycles. In this study, we apply growth models based on tree-ring data and allometric equations to estimate site-specific management options for timber resources of the commercial species Calophyllum brasiliense (Calophyllaceae) comparing 16 wetland sites across different Brazilian ecoregions, the Amazon, Cerrado (savannah), Pantanal and Mata Atlântica (Coastal Atlantic Rainforest). By modeling diameter, height, and volume growth parameters, we estimate site-specific minimum logging diameters (MLD) and felling cycles analyzing a total of 341 trees. Between ecoregions, the mean diameter increments varied slightly between 4.3 ± 1.6 mm year−1 in the Amazon region (average of six sites), 4.0 ± 0.8 mm year−1 in the Cerrado and Pantanal (average of seven sites), and 4.5 ± 1.2 mm year−1 in the Mata Atlântica (average of three sites). However, between sites, we observed significant differences in diameter and volume increment rates, resulting in felling cycles varying from 14 to 63 years and MLDs in the range of 35–81 cm. This clearly indicates that forest management practices in Brazil, which generally applies a feeling cycle of 25 years and a diameter-cutting limit of 50 cm cannot guarantee a sustainable timber harvest. Timber resource management of this species requires site-specific criteria and should be restricted at sites with a low wood productivity. Moreover, long-term monitoring of the population structure and dynamics is necessary for a better understanding of the relationship between environmental factors and population dynamics, especially concerning the regeneration processes.

Background Species-specific information on distribution and demographic patterns provides important implications for conservation and fisheries management. However, such information is often lacking for morphologically-similar species, which may lead to biases in the assessments of these species and even decrease effort towards sustainable management. Here, we aimed to uncover the distribution range, population structure and demographic history for four exploited Trichiurus cutlassfishes using genetics. These cutlassfishes contribute substantial global fisheries catch, with a high proportion of catch harvested from the NW Pacific. Methods We chose the widely available mitochondrial 16S ribosomal RNA (16S) as the genetic marker for cutlassfishes. We compiled the 16S sequence data from both the GenBank and a survey of trawler catch samples along the NW Pacific coasts 22–39°N. Genealogical relationships within each species was visualized with haplotype networks and potential population differentiations were further evaluated with AMOVA. Demographic histories were estimated using neutrality test, mismatch analysis, and the Bayesian skyline plot. The reconstructed phylogenetic trees were used to delimit and estimate the divergence time of species and included populations. Results In each of two cosmopolitan species, T. lepturus and T. nanhaiensis, we observed distinct populations along the coasts of warm oceans; such population differentiation might result from historical geographic barriers in the Pleistocene. In the NW Pacific, four Trichiurus species vary in their distribution habitats, which reflect differential ecological niches among these species. The small-sized T. brevis are primarily found in nearshore habitats; the warm-affiliated T. nanhaiensis are present along the path of the Kuroshio Current; the cold-affiliated T. japonicus spatially diverged from the widely-distributed T. lepturus, with the latter mainly occupy in warmer regions. Despite these differences, a single well-mixing fish stock, thus one management unit, was identified in each of the four species, presumably due to expansion of their population sizes predated the Last Glacial Maximum and a lack of distribution barrier. The most dominant T. japonicus, which have at least one magnitude higher effective population size than the others, show a unique abrupt size expansion event at 75 to 50-kilo years ago when the low sea level occurred during the ice age. Main conclusions The demographic history revealed by our genetic analyses advances understanding of the current distribution and population structure for these congeneric species. Moreover, the uncovered population structure provides insight into the assessment and management of these species. Such information complements contemporary knowledge about these species and enables us to forecast their ability to resist future environmental and anthropogenic disturbances.

Background Species-specific information on distribution and demographic patterns provides important implications for conservation and fisheries management. However, such information is often lacking for morphologically-similar species, which may lead to biases in the assessments of these species and even decrease effort towards sustainable management. Here, we aimed to uncover the distribution range, population structure and demographic history for four exploited Trichiurus cutlassfishes using genetics. These cutlassfishes contribute substantial global fisheries catch, with a high proportion of catch harvested from the NW Pacific. Methods We chose the widely available mitochondrial 16S ribosomal RNA (16S) as the genetic marker for cutlassfishes. We compiled the 16S sequence data from both the GenBank and a survey of trawler catch samples along the NW Pacific coasts 22–39°N. Genealogical relationships within each species was visualized with haplotype networks and potential population differentiations were further evaluated with AMOVA. Demographic histories were estimated using neutrality test, mismatch analysis, and the Bayesian skyline plot. The reconstructed phylogenetic trees were used to delimit and estimate the divergence time of species and included populations. Results In each of two cosmopolitan species, T. lepturus and T. nanhaiensis, we observed distinct populations along the coasts of warm oceans; such population differentiation might result from historical geographic barriers in the Pleistocene. In the NW Pacific, four Trichiurus species vary in their distribution habitats, which reflect differential ecological niches among these species. The small-sized T. brevis are primarily found in nearshore habitats; the warm-affiliated T. nanhaiensis are present along the path of the Kuroshio Current; the cold-affiliated T. japonicus spatially diverged from the widely-distributed T. lepturus, with the latter mainly occupy in warmer regions. Despite these differences, a single well-mixing fish stock, thus one management unit, was identified in each of the four species, presumably due to expansion of their population sizes predated the Last Glacial Maximum and a lack of distribution barrier. The most dominant T. japonicus, which have at least one magnitude higher effective population size than the others, show a unique abrupt size expansion event at 75 to 50-kilo years ago when the low sea level occurred during the ice age. Main conclusions The demographic history revealed by our genetic analyses advances understanding of the current distribution and population structure for these congeneric species. Moreover, the uncovered population structure provides insight into the assessment and management of these species. Such information complements contemporary knowledge about these species and enables us to forecast their ability to resist future environmental and anthropogenic disturbances.