Floral Assemblages Research Articles

Lower Permian Gondwana sequence of Rajhara (Daltonganj Coalfield), Damodar Basin, India: floristic and geochemical records and their implications on marine ingressions and depositional environment.

Early Permian floral diversity and palaeodepositional environment of the Lower Permian Rajhara sequence of Damodar Basin have been studied based on mega-, microfossil and geochemical proxies. Even though Gondwana sediments are generally considered as fluvio-lacustrine deposits, recent studies indicate marine inundations with patchy records. Here in the present study, an attempt has been made to address the changeover from fluviatile to shallow marine conditions and also to address the palaeodepositional aspects. Luxuriant vegetation during deposition of the Lower Barakar Formation generated thick coal seams. The macroplant fossil assemblage shows Glossopteridales, Cordaitales and Equisetales comprising one palynoassemblage with the dominance of bisaccate pollen grains having glossopterid affinities. However, Lycopsids are absent in the megafloral record and are represented in megaspore assemblage. The present floral assemblage led to envisage the presence of dense forest with swampy conditions and prevalence of warm and humid climate during the deposition of Barakar sediments. Correlation with the coeval Indian assemblages and those from other Gondwanan continents also supports an Artinskian age and reveals a stronger affinity with flora of Africa than that of South America. Biomarker analysis reveals low pristane/phytane values (0.30-0.84), noticeable absence of hopanoid triterpenoids and long-chain n-alkanes that is attributed to the obliteration of organic compounds and subsequent alteration of composition due to thermal effect. The high chemical index of alteration, A-CN-K plot and PIA also suggest severe denudation under a warm/humid climate. The V/Al2O3 and P2O5/Al2O3 indicated freshwater-near-shore conditions. However, signature of possible marine influence is identified from Th/U and Sr/Ba ratios resulted from the eustatic fluctuations during Permian.

Modeling the potential distribution of floristic assemblages of high Andean wetlands dominated by Juncaceae and Cyperaceae in the Argentine Puna

Aims: The aim of this work was to model the distribution of suitable environmental conditions of vegas with specific floristic characteristics. Vegas are high Andean wetlands that represent the main sequestered carbon stocks, biodiversity hotspots, and water regulating systems in the region. In these wetlands, plant communities are the main biological factor that determines functional processes, and plant species assemblages are associated with different ecogeographic features. Study area: Argentine Central Andean Puna ecoregion. Methods: For two different floristic assemblages of vegas, we develop ecological niche models of n-dimensional minimum volume ellipsoids through NicheToolBox, then obtain potential distribution maps. One floristic assemblage was dominated by the cushion-structured plant Oxychloe andina (Juncaceae) and the other by plants of the Cyperaceae family. Results: Elevation and precipitation were the main environmental factors determining the distribution of the two floristic assemblages. Juncaceae dominated vegas tend to be located in high, humid, and cold places, while Cyperaceae vegas are found at a lower elevation, with less humidity, and higher temperatures. According to the dominant climatic gradient in the region, potential distribution maps show that vegas of Juncaceae are commonly found towards the Northeast of the Puna while Cyperaceae vegas are more frequent at lower elevations to the South of the region. Conclusions: This study represents the first approach to niche modeling based on plant communities in vegas of the Argentine Puna, providing knowledge on the environmental factors that limit their distribution. This information could serve as a planning tool in a region exposed to growing perturbations such as mining and climate change. Taxonomic reference: Zuloaga et al. (2019). Abbreviations: AUC = Area Under the ROC Curve; NDVI = Normalized Difference Vegetation Index; ROC = Receiver Operating Characteristic.

The Paleogene continental basins from SE France: New geographic and climatic insights from an integrated approach

New insights into the geodynamic evolution, the paleogeographic framework and the paleoclimatic setting of the Upper Eocene-Oligocene lacustrine basins from South-East France have been provided by an integrative approach combining geochronology, micropaleontology and stable isotope analyses. UPb dating on calcite, pollen-based climatostratigraphy and strontium and sulfur isotope signatures of sulfates provided a robust chronostratigraphic framework for the Upper Eocene and Oligocene succession from the Vistrenque, Alès and Roussillon basins. The thick Priabonian- lower Rupelian lacustrine succession from the Vistrenque Basin is interpreted to be deposited in a strike-slip basin associated with the latest stages of pyrenean shortening. Floral assemblages are used to reconstruct the vegetation cover in the lacustrine systems and their neighbouring lowlands and highlands. Composition of saltwater inferred from strontium and sulfur isotope signatures of sulfates, the occurrence of calcareous nannofossils, dinoflagellate cysts and pollen grains of mangrove-related plants provided strong evidence for marine intrusions into the Alès Basin during the Priabonian and the Vistrenque Basin during the Rupelian and Chattian. Paleogeographic reconstructions of Southeast France during the Priabonian and late Rupelian strongly suggest marine incursions from the Alpine Sea via two potential pathways: upper Rhône Valley via the Crest Sill and lower Rhône Valley via the Haut-Var Pyrenean synclines. On the other hand, Upper Oligocene evaporite basins in the Camargue area have been subjected to marine intrusions from the Western Mediterranean Sea following the collapse of the eastern pyrenean relief during the Liguro-Provençal rifting stage. Finally, pollen analysis and Climate Amplitude Method revealed a brief but significant stage of cooling and aridification at the very base of the Rupelian which could represent the regional and terrestrial expression of the global climate cooling following the Eocene-Oligocene Transition.

Carbon isotope values for grasses in Madagascar's Central Highlands establish baselines for historical and paleoecological research

Societal Impact StatementGrasses are significant drivers of fires and are the primary food source for cattle in Madagascar's Central Highlands. However, their extent and importance to animals and people in the past remain poorly understood. Clarifying the history of Malagasy grasslands is necessary for building climate resilient food systems and supporting carbon stores that also conserve biodiversity. We generated chemical data for grasses that grow in open habitats in central Madagascar, which will help improve our understanding of the ecological and economic importance of modern grassy ecosystems, reconstruct the regional history of grasses, and anticipate how vegetation may respond to changing climate and rising atmospheric carbon dioxide levels.Summary Stable carbon isotope (δ13C) data for Malagasy grasses are needed to establish expected values for C3 and C4 grasses from particular regions in Madagascar, and possible differences among different grass lineages, or species with different distributions or adaptations. These data, in turn, may help inform how widespread grasses were in the past, and the importance of grasses to endemic and domesticated animals as well as people over time. We analysed both δ13C and weight %C:N from 63 Poaceae species that grow in open grassy biomes in Madagascar's Central Highlands and explored how these values relate to multiple variables, including encounter frequency, distribution, lineage, adaptations to grazing and fire and the typical floral assemblage in which each species occurs. Of the species sampled, 56 are C4 and seven are C3. There are no differences in δ13C or weight %C:N among either C3 or C4 species with different distributions or adaptations, from different assemblages, or that are frequently or infrequently encountered. However, there are differences in both δ13C and weight %C:N among C4 lineages, and the single C3 arundinoid (Styppeiochloa hitchcockii) has larger weight %C:N than C3 Paniceae. Our results provide a foundation for evaluating reliance on C4 resources by people, as well as domesticated and endemic animals both today and in the past. We encourage gathering additional comparative data for co‐occurring individual plants from the same open grassy biome localities, as well as other species, habitats and regions in Madagascar.

Fossil floral assemblage from the Upper Triassic Grabowa Formation (Upper Silesia, southern Poland)

Fossil floral assemblage from the Upper Triassic Grabowa Formation (Upper Silesia, southern Poland)

Comprehensive Record of Megafossils from the Rajmahal Basin, Jharkhand, India

The study provides the first comprehensive record of the plant megafossils mainly Glossopteris flora from the Barakar Formation, Rajmahal Open Cast Mine, Rajmahal Basin, Jharkhand. The assemblage is composed of pteridophytes and gymnosperms. The pteridophytes comprise Equisetalean axes (order Equisetales), whereas, gymnosperms include nine species of Glossopteris including Glossopteris communis, G. damudica, G. gigas, G. indica, G. lanceolatus, G. longicaulis, G. oldhamii, G. taenioides, G. tenuifolia along with Vertebraria indica and Noeggerathiopsis hislopi. The present investigation adds to the knowledge of the Glossopteris flora of India, especially that of the Rajmahal Basin from where the plant fossil records are sporadic. The area is a treasure for palaeobotanical studies as evinced by different fossil localities. However, the localities are degraded by mining activities performed by private companies and hence systematic investigation for such vegetation is vital to create a palaeobotanical database before their complete degradation. The floral assemblage compares with earlier known assemblages, recorded from the Barakar Formation of other Lower Gondwana basins of peninsular India.

Ecology, evolution, and conservation of Ethiopia’s biodiversity

Ethiopia is home to one of the richest and most unique assemblages of fauna and flora on the African continent. Contained within its borders are two major centers of endemism, the mesic Roof of Africa (also known as the Ethiopian Highlands) and the arid Horn of Africa, resulting from the country’s varied topography and consequent geographic isolation. These centers of endemism are crucial to global conservation as evidenced by their classification within the Eastern Afromontane and Horn of Africa biodiversity hotspots, respectively. Ethiopia’s diverse ecosystems and the biodiversity they contain are increasingly threatened by climate change and the growing impacts of Africa’s second largest human and largest livestock populations. In this paper, we focus on several key areas of recent and ongoing research on Ethiopian biodiversity that have broadened our understanding of nature and its conservation in Africa. Topics explored include the behavioral ecology of Ethiopia’s large social mammals, the ecology and conservation of its unique coffee forests, and Ethiopian approaches to community conservation, fortress conservation, and nature-based solutions. We also highlight the increasing prominence of Ethiopian scientists in studies of the country’s biodiversity in recent decades. We suggest promising avenues for future research in evolutionary biology, ecology, systematics, and conservation in Ethiopia and discuss how recent and ongoing work in Ethiopia is helping us better understand and conserve nature in the human-dominated landscapes of Africa and other tropical regions today.

Multiple drivers and lineage-specific insect extinctions during the Permo–Triassic

The Permo–Triassic interval encompasses three extinction events including the most dramatic biological crisis of the Phanerozoic, the latest Permian mass extinction. However, their drivers and outcomes are poorly quantified and understood for terrestrial invertebrates, which we assess here for insects. We find a pattern with three extinctions: the Roadian/Wordian (≈266.9 Ma; extinction of 64.5% insect genera), the Permian/Triassic (≈252 Ma; extinction of 82.6% insect genera), and the Ladinian/Carnian boundaries (≈237 Ma; extinction of 74.8% insect genera). We also unveil a heterogeneous effect of these extinction events across the major insect clades. Because extinction events have impacted Permo–Triassic ecosystems, we investigate the influence of abiotic and biotic factors on insect diversification dynamics and find that changes in floral assemblages are likely the strongest drivers of insects’ responses throughout the Permo–Triassic. We also assess the effect of diversity dependence between three insect guilds; an effect ubiquitously found in current ecosystems. We find that herbivores held a central position in the Permo–Triassic interaction network. Our study reveals high levels of insect extinction that profoundly shaped the evolutionary history of the most diverse non-microbial lineage.

Early Jurassic dinosaur-dominated track assemblages, floristic and environmental changes in the Holy Cross Mountains region, Poland

The Early Jurassic succession of the Holy Cross Mountains region in Poland offers a rare opportunity to study ecosystem complexity during the evolution and diversification of early dinosaurs, especially herbivorous ones. The section consists of continental and coastal deposits containing fossil assemblages spanning nearly 25 My of changes in terrestrial plants and some groups of invertebrates and tetrapods. Based on macrofossils and pollen and spores, the broader characteristics of the flora in this succession are presented. The floral assemblages show typical Early Jurassic characteristics and contain lycopsids, sphenopsids, ferns, cycadaleans, bennettitaleans, gnetaleans and ginkgoaleans, as well as conifers, and are similar to other Hettangian–Toarcian floral successions in Europe, showing the presence of a vast coniferous forest dominated by Hirmeriella in the early Hettangian, replaced by ginkgophyte-dominated floras in younger stages and araucarian conifer-dominated forests in the late Pliensbachian. Dinosaurs are documented mainly from their trace fossils (tracks and coprolites). Six distinct track assemblages (stratigraphically separated ichnoassemblages) of different ages can be identified. Current evidence indicates that while Anomoepus tracks are abundant throughout the long Hettangian–late Pliensbachian interval, medium-sized to large ornithischian tracks do not occur below the lower–middle Hettangian transition zone, associated with the first major marine transgression in the region. Hettangian strata with different theropod tracks ( Grallator, Anchisauripus, Eubrontes, Kayentapus , cf. Megalosauripus ), small Anomoepus tracks, numerous medium-sized Anomoepus -like tracks, Moyenisauropus tracks, tetradactyl tracks of sauropodomorphs (cf. Pseudotetrasauropus ) and oval-shaped tracks of sauropods ( Parabrontopodus ) significantly contrast with the higher part of the Lower Jurassic succession (upper Pliensbachian Drzewica Formation and middle–upper Toarcian Borucice Formation) containing new types of medium-sized to large theropod tracks ( Therangospodus ), small and medium-sized bird-like tridactyl tracks (cf. Trisauropodiscus , cf. Anomoepus ), exceptionally large, oval-shaped sauropod tracks ( Sauropoda indet.), and new types of medium-sized and large ornithischian tracks (cf. Deltapodus , cf. Anomoepus ). This points to a noticeable difference between the Hettangian and late Pliensbachian–Toarcian dinosaur ichnofaunas and may facilitate the study of regional and global changes and correlations. Both the palaeofloras and dinosaur trace fossils document ecosystem diversity and ecosystem changes, presented here in review form. The nature of these changes requires more detailed study, but preliminary results suggest the occurrence of rather complex and pronounced transformations in the dinosaur communities of the Holy Cross Mountains region. Based on our observations, the most significant event in Early Jurassic ecosystems took place within the Hettangian (change in floristic composition, the emergence of new groups of dinosaurs), but we also found what we believe to be a record of a major faunal turnover across the late Pliensbachian–middle–late Toarcian interval.

Directive Strategies for Conservation and Threat Mitigation in Similipal Biosphere Reserve

Biosphere Reserves (BR), the multipurpose protected areas with boundaries circumscribed by a legislative framework and are recognized as the 'laboratory for sustainable development'. Similipal Biosphere Reserve (SBR) in Odisha, one of the BRs in the eastern zone of India, has an array of habitats and ecosystems such as mountains, grasslands, wetlands, moist deciduous forests, and is rich in biological resources (e.g., flora and fauna), including some of the endemic species. The available reports, as acquired from the web-based search engine, reveal the presence of floral assemblage encompassing aquatic plants, bryophytes, algal diversity, lichens, edible fruits, medicinal plants; and the faunal richness inclusive of almost all the animal taxa, viz ., mammals, aves, reptiles, amphibia, pisces and a range of invertebrate species. Further, reports on traditional ecological knowledge (TEK) and ethnobotanical aspects from the SBR are also available. This article highlights, in brief, various ecological and socio-economical facets of SBR based on the available reports and scholarly literatures. Since most of the scientific explorations have been undertaken from an academic perspective, there is a need for intervention with a pluralistic approach for conservation of natural resources in the biosphere reserve. This article is an offshoot of an attempt to consolidate the existing reports/literature on the SBR and prioritize management interventions to mitigate the threats. Further, to facilitate an efficient, comprehensive management plan, a way forward, by identifying and integrating broad aspects for conservation, is presented that is applicable for SBR and all PAs of the country in general

Directive Strategies for Conservation and Threat Mitigation in Similipal Biosphere Reserve

Biosphere Reserves (BR), the multipurpose protected areas with boundaries circumscribed by a legislative framework and are recognized as the 'laboratory for sustainable development'. Similipal Biosphere Reserve (SBR) in Odisha, one of the BRs in the eastern zone of India, has an array of habitats and ecosystems such as mountains, grasslands, wetlands, moist deciduous forests, and is rich in biological resources (e.g., flora and fauna), including some of the endemic species. The available reports, as acquired from the web-based search engine, reveal the presence of floral assemblage encompassing aquatic plants, bryophytes, algal diversity, lichens, edible fruits, medicinal plants; and the faunal richness inclusive of almost all the animal taxa, viz ., mammals, aves, reptiles, amphibia, pisces and a range of invertebrate species. Further, reports on traditional ecological knowledge (TEK) and ethnobotanical aspects from the SBR are also available. This article highlights, in brief, various ecological and socio-economical facets of SBR based on the available reports and scholarly literatures. Since most of the scientific explorations have been undertaken from an academic perspective, there is a need for intervention with a pluralistic approach for conservation of natural resources in the biosphere reserve. This article is an offshoot of an attempt to consolidate the existing reports/literature on the SBR and prioritize management interventions to mitigate the threats. Further, to facilitate an efficient, comprehensive management plan, a way forward, by identifying and integrating broad aspects for conservation, is presented that is applicable for SBR and all PAs of the country in general

The collapse of the protoprecordillera and unification of the Paganzo and Calingasta-uspallata basins: Retamito Formation a key in the integrative biostratigraphic and palaeoenvironmental model

The Retamito Formation is located at the southernmost of Oriental Precordillera, San Juan, Argentina. This contribution defines eight facies associations: FA1 (breccias and conglomerates) linked to initial valley fills by a chaotic basal colluvium fan and/or karst collapse. FA2 (sandstones and gravelly sandstones) is interpreted as deposits of coastal shoreface systems. The FA3 (coal and coaly mudstones) could be attributed to a paralic environment and represent the first record of plant remains of Argentina (NBG Biozone). FA4 (gravel-bed) is interpreted as a proximal alluvial system. FA5 (shales) contains the first record of brachiopods and a new taxa Komiellanetes cesariae sp. nov, probably representing an eastward extension of the TS fauna in a brief marine incursion. FA6 (mudstones and sandstones) is deposited in a delta front system. The FA7 (red mudstones) are linked to lagoons deposits, where they preserved a floristic assemblage of megaflora remains (Ferugliocladus Superbiozone) composed of seeds, stems, and leaves that are most likely of Permian age. Finally, the FA8 (interbedded sandstones and mudstones) is interpreted as deposited by an anastomosed fluvial system. We present paleoenvironmental and paleontological data of the Retamito Formation correlated with the neighboring Andapaico and Ansilta formations in an east-west transect. This correlation parsimoniously linked the Paganzo and Calingasta-Uspallata Basins in seven filling scenarios (temporal stages Ts). From Ts1 to Ts5, both basins were separated by the Protoprecordillera. Common paleoenvironments on both basins suggest unification of them in Ts6 and Ts7. These temporal stages are paleontologically controlled by two new fossil levels and the corresponding sedimentary paleoenvironments that contain them. Thus, it could be demonstrated that the positive element of the Protoprecordillera was active until the Upper Carboniferous and collapsed towards Early Permian, unifying both basins in this sector of Gondwana.

The New flora from the Permian of the Intrasudetic Basin, Poland

A floral assemblage was collected from a new Polish locality (Janików) situated on the Czech- Polish border in the Intrasudetic Basin. It was found in the lower Permian (Asselian) Ruprechtice Horizon, of the Olivětín Member, Broumov Formation. The plant fossils were usually fragmentary, and the following taxa were determined: Alloiopteris aff. erosa, Nemejcopteris feminaeformis, Senftenbergia sp., Lobatopteris sp., Sphenopteris sp., Cyathocarpus cf. densifolius, Lobatopteris cf. geinitzii, Lobatopteris nov. sp., Dicksoniites cf. plukenetii, Autunia conferta, Cordaites sp. and seeds. Alloiopteris was first recorded in the Permian. The assemblage is composed predominantly of ferns and pteridosperms that tend to be hygrophilous to mesophilous floral elements. The flora from the Otovice and Ruprechtice horizons is usually rich in walchian conifers and peltasperms (Autunia conferta), and so the Janików flora is quite different with its hygrophilous elements. The fragmentary preservation suggests long transport distances, and probably only the remains of flora growing on the lakeshore were deposited in the calcareous bituminous shales. This coastal vegetation probably formed a barrier to mesophilous plants growing further from the lake, so their fragments are more sporadic.

Flexible diets enable pollinators to cope with changes in plant community composition

AbstractSwitching plant species visited by pollinators (partner flexibility) has been proposed as a behavioural mechanism able to attenuate the negative impacts of shifts in plant communities on pollination. However, it is unclear whether the magnitude of such response is generalizable or depends on the environmental context. Moreover, the ability of pollinators to exploit plants with dissimilar traits (trait flexibility) has been overlooked, even though it can affect the spectrum of new partners available.To shed some light on this problem, we quantified partner and trait flexibility in five communities from four different environments, from Alpine to semi‐arid. We evaluated whether the rate at which pollinators incorporated new plant species throughout the flowering season was similar across communities or context dependent. Then, we assessed whether pollinators changed the type of flowers visited and if such trait flexibility was related to their capacity to visit new plant species. Finally, we developed an agent‐based model to explore whether diet flexibility can protect pollination when the plant community changes. To this end, we used scenarios of phenological decoupling.In general, pollinators switched interaction partners to cope with the temporal replacement of plant species. Yet, the magnitude of such behaviour varied across communities, probably in response to differences in the number of floral resources available. Also, pollinators were able to visit plant species with dissimilar traits, though both components of diet flexibility (partner identity and traits) did not necessarily covary. Thus, to have a full picture of pollinators' diet flexibility, we need to consider the floral traits of partners. Finally, our theoretical model shows that diet flexibility can protect pollination after shifts in plant communities, but that such positive effects are limited by trait‐matching between co‐occurring species.Synthesis. Overall, our study highlights the importance of incorporating plant traits when evaluating the ability of pollinators to find new interaction partners. Besides, our simulation results suggest that diet flexibility may not unequivocally protect pollination against changes in plant communities, especially if they entail shifts in the characteristics of the floral assemblage, and hence, the ability of pollinators to find new interaction partners can be compromised.

Asian monsoon and vegetation shift: evidence from the Siwalik succession of India

AbstractQuantitative Miocene climate and vegetation data from the Siwalik succession of western Nepal indicate that the development of the Indian summer monsoon has had an impact, though in part, on vegetation changes. The climate and vegetation of the Lower (middle Miocene) and Middle (late Miocene–Pliocene) Siwalik successions of Darjeeling, eastern Himalaya, have been quantified. Reconstructed climate data, using the Coexistence Approach, suggest a decrease in winter temperatures and precipitation during the wettest months (MPwet) from the Lower to Middle Siwalik. The floristic assemblage suggests that Lower Siwalik forests were dominated by wet evergreen taxa, whereas deciduous ones became more dominant during the Middle Siwalik. The vegetation shift in the eastern Himalayan Siwalik was most likely due to a decrease in MPwet. The quantified climate–vegetation data from the eastern and western Himalayan Siwalik indicate that changes in the Indian summer monsoon had a profound impact on vegetation development during the period of deposition. We suggest that the decrease in winter temperature and summer monsoon rainfall during the Middle Siwalik might be linked with the Northern Hemisphere glaciation/cooling or a number of other things that were also going on at the time, including the continued rise of the Himalaya, and drying across the Tibetan region, which may have affected atmospheric circulation regionally.

Hiding in plain sight: combining field-naturalist observations and herbarium records to reveal phenological change

As the climate warms, northern ecosystems are experiencing warmer winters and seasonal climatic shifts. Vascular plants are expected to respond to climate change by adjusting flowering or seeding periods. To determine how a native mixed-wood boreal floral assemblage has responded to warming temperatures over the 20th century, we collated historical observations made by field-naturalists as well as voucher data from the Thunder Bay region of Ontario, Canada. Combining these datasets, we performed regression analyses on 11 species of spring-flowering vascular plants to evaluate temporal trends and used spring cumulative growing degree day (sGDD0) to determine the influence of climate on flowering times. Four species showed consistent positive temporal trends (i.e., flowered later with time), while four species (three of which also demonstrated temporal trends) showed negative trends with sGDD0 (i.e., flowered earlier with an increased number of degree days above 0°C). The unexpected observation of later flowering times but predicted observation of earlier blooming with increased sGDD0 indicates that the inclusion of climate metrics may be necessary to determine the response of native vascular plants to the onset of changes in their environment. These observations were not statistically significant when field-naturalist or herbarium voucher data were analyzed separately, possibly due to low statistical power. Combining data from both sources, however, revealed common responses to climate warming among species within an ecoregion.

Responses of Potassium on Floral Assemblages in the Forest Floors of West Bengal

Responses of Potassium on Floral Assemblages in the Forest Floors of West Bengal

Ecological Networks in Urban Forest Fragments Reveal Species Associations between Native and Invasive Plant Communities.

Forest fragments are characteristic features of many megacities that have survived the urbanisation process and are often represented by unique assemblages of flora and fauna. Such woodlands are representations of nature in the city—often dominated by non-native and invasive species that coexist with resilient native congeners and purposefully introduced flora. These forest fragments also provide significant ecosystem services to urban society and therefore, understanding their compositional patterns is of considerable importance for conservation and management. In this work, we use a complex network approach to investigate species assemblages across six distinct urban forest fragments in the South Delhi Ridge area of the National Capital Territory, India. We generate bipartite ecological networks using conventional vegetation sampling datasets, followed by network partitioning to identify multiple cliques across the six forest fragments. Our results show that urban woodlands primarily form invasive–native associations, and that major invasive species, such as Prosopis juliflora and Lantana camara exclude each other while forming cliques. Our findings have implications for the conservation of these urban forests and highlight the importance of using network approaches in vegetation analysis.

Diversity and foraging behaviour of floral visitors assemblages in onion Allium cepa L.

Anthophilous insects are of key importance for onion reproduction due to the protandrous nature of flowers, related to inbreeding avoidance. We documented the diversity of floral visiting insects on onion flowers at the ICAR-Indian Institute of Horticultural Research, Bengaluru, Karnataka, India, during 2019-21. The pollinator community is composed of thirty hymenopteran species, sixteen dipteran species, eight lepidopteran species, four hemipteran species, and one species from Coleoptera. From these, Hymenoptera and Diptera contributed >75% of the floral visitors. The majority of the floral visits by the anthophilous insects were for collecting nectar (81.59%) followed by nectar as well as pollen foraging (9.97%) and only pollen (8.44%). The proportion of stigma contact did not depend on the body size of the floral visitor. However, stigma contact depends on whether floral visitors collected nectar or pollen and also on the head width of the floral visitor. The present study helps to understand the pollination efficiency of pollination candidates for onion. Further, there is a need to study the pollen harvest and effective stigmatic pollen deposition by the floral visitors.

Late Messinian flora from the post-evaporitic deposits of the Piedmont Basin (Northwest Italy)

In the Piedmont Basin (PB), one of the northernmost Mediterranean basins recording the Messinian Salinity Crisis (MSC), pollen and plant macroremains (leaves, fruits and seeds) were studied in four sedimentary sections of the post-evaporitic interval (5.6–5.33 Ma). The joint palaeobotanical investigations of the two datasets allowed the reconstruction of a floristic assemblage which consists of 133 taxa (95 woody and 38 non-woody taxa). The lowland/coastal vegetation reconstructed by integrating macro- and microfossil data exhibits several analogies with existing “types/formations” of South-Southeast Asia, whereas taxa occurring solely in the pollen record suggest the existence of altitudinal forests with conifers and a few angiosperms. We suggest that the generalized type of lowland, zonal palaeovegetation in the post-evaporitic Messinian of the PB was of no-analog type, but most similar to either “mixed mesophytic forests” or “broad-leaved evergreen forests”, which indicates a Köppen-Trewartha subtropical palaeoclimate.