Plant Species Assemblages Research Articles

Juncus snowii (Juncaceae), a New Rare Species Endemic to the Altamaha Grit of Georgia, U.S.A.

A new species, Juncus snowii W. M. Knapp & R. Carter (Juncaceae), is described from two counties of the Altamaha grit, a sandstone formation in the coastal plain physiographic province of Georgia, U.S.A. This new species resembles other members of Juncus L. sect. Ozophyllum Dumort. but is readily distinguished by a combination of characters including its typically annual life history, diminutive habit, and small capsules and tepals. The type locality is an area of geologic interest that supports a unique assemblage of rare and endemic plant species. Color photographs are provided for the new species, as well as preliminary conservation status assessments using NatureServe criteria (Critically Imperiled with extinction [G1]) and IUCN Red List criteria (Vulnerable [VU D2]).

Searching to improve connectivity in fragmented landscapes: Road verges as complementary habitats

AbstractAimsFunctional connectivity is crucial for conserving biodiversity and ecosystem services in fragmented landscapes. Linear landscape elements play an important role in providing refuge for plants and pollinators, as well as serving as biological corridors. The aim of this study was to assess the importance of road verges in maintaining the ecological connectivity of plant species assemblages in the Tandilia mountain system.LocationSouth America, Southern Pampa region of Argentina, Tandilia mountain system.MethodsUsing graph theory, landscape connectivity was quantified both at landscape scale and at the patch scale using the probability connectivity index (PCnum), taking into account the dispersal ability of observed species. The contribution of each landscape element to habitat availability and connectivity was evaluated using different fractions of the PCnum metric. Likewise, the influence of connectivity variables in explaining species assemblages grouped by functional categories was investigated using canonical ordination techniques.ResultsThe inclusion of road verges led to an 81% increase in overall connectivity at a threshold distance of 500 m. Connectivity significantly explained the assemblages of entomophilous plant species for all dispersal distances. Annual species assemblage variation was associated with intra‐patch connectivity. Variation in perennial and shrub species assemblages was explained by intra‐patch and inter‐patch connectivity.ConclusionsPreservation and restoration of these linear landscape elements play a pivotal role in transitioning toward more sustainable agroecosystems. This ecological and practical information may help prioritize plant species and the sites used to restore an essential but neglected ecosystem.

Increased hydraulic risk in assemblages of woody plant species predicts spatial patterns of drought-induced mortality

Predicting drought-induced mortality (DIM) of woody plants remains a key research challenge under climate change. Here, we integrate information on the edaphoclimatic niches, phylogeny and hydraulic traits of species to model the hydraulic risk of woody plants globally. We combine these models with species distribution records to estimate the hydraulic risk faced by local woody plant species assemblages. Thus, we produce global maps of hydraulic risk and test for its relationship with observed DIM. Our results show that local assemblages modelled as having higher hydraulic risk present a higher probability of DIM. Metrics characterizing this hydraulic risk improve DIM predictions globally, relative to models accounting only for edaphoclimatic predictors or broad functional groupings. The methodology we present here allows mapping of functional trait distributions and elucidation of global macro-evolutionary and biogeographical patterns, improving our ability to predict potential global change impacts on vegetation.

Floristic Survey of Deedwana Tehsil, District Nagaur, Rajasthan

Abstract: The present research paper presents a comprehensive floristic study of Deedwana Tehsil, District Nagaur, Rajasthan, aimed at documenting the plant diversity and understanding its ecological significance. The study involved extensive field surveys, specimen collections, and interviews with local experts to identify and classify the plant species within the region. The results revealed a diverse and unique assemblage of plant species in Deedwana Tehsil, representing various vegetation types and habitats. The enumeration of identified plant species showcased a rich floral diversity, including both native and exotic species. A total of 331 species of angiospermic plants belonging to 218 genera and 65 families were recorded including four series of natural vegetation in Deedwana tehsil: 1. Acacia nilotica-Maytenus emarginata-Balanites aegyptiaca series 2. Prosopis cineraria-Crotalaria burhia-Leptadaenia pyrotechnica series. 3. Prosopis cineraria- Capparis decidua-Tephrosia purpuria series and 4. Suaeda fruticosa-Cressa cretica–Heliotropium curassavicum series. (Quereishi, 2018). The study also provide information about the traditional uses of plants by local communities, providing insights into their cultural significance and medicinal applications. Traditional knowledge holders and local healers shared valuable information about medicinal plant practices, adding to the understanding of the region's traditional healthcare systems. The study also analyzed the major threats faced by the flora of Deedwana Tehsil, such as habitat loss, overgrazing, climate change, and unsustainable resource extraction. These findings highlighted the urgent need for conservation and sustainable management initiatives to protect the region's botanical wealth

Gradient Analysis and Classification of Tall Forb Communities in the Bridger-Teton National Forest, United States

Tall forb−mixed upland−herb communities are exemplified by high plant diversity and a profusion of luxuriant wildflowers throughout subalpine mountain parklands of the interior western United States. These unique and ecologically important communities remain largely unclassified in terms of their biological and physical attributes and ecological responses to management and disturbances. Land managers need respective classifications to evaluate and guide conservation planning and management for tall forb communities where they occur. In this study, 23 sites from four subalpine areas representing reference tall forb plant communities on the Bridger-Teton National Forest were identified and selected for analysis after a sustained cessation of grazing activities. The purpose of the study was to quantitatively examine tall forb community stands and provide a basis for developing a classification system for identifying future ecological sites, which are essential in conservation planning, implementation and management, and monitoring. Seven tall forb cluster groups were identified with unique plant composition and specific environmental gradients (i.e., plant species richness, diversity indices, elevation, average annual precipitation, surficial geology, three-dimensional geomorphic descriptions, soil clay content diversity dynamics, and foliar, ground, and surface cover). Among the seven cluster groups, we identified 31 families, 112 genera, and 158 plant species on the sample sites (61 species representing native indicator reference species, 86 native secondary indicator species, and 10 introduced non-native species). Beta diversity and plant species turnover ranged from 6.7% to 41.9% among the seven cluster groups, indicating discrete differences in plant species assemblages, plant associations, and site dynamics. The seven tall forb clusters are characteristic of specific and unique plant species composition, species diversity, and environmental factors. Therefore, a specialized site approach with respective guidelines is recommended for assessing and conserving discrete tall forb ecological sites and maintaining key dominant native indicator reference species, rangeland health and proper functioning condition, and defined monitoring protocols.

Spontaneous urban vegetation as an indicator of soil functionality and ecosystem services

AbstractQuestionsOur study focused on spontaneous vegetation in urban greenspaces in a Mediterranean city with the aim of relating plant community properties with ecological services along soil disturbance gradients. We asked which plant communities have the greatest plant biodiversity and soil carbon storage and the best‐performing nutrient cycles and water regulation.LocationMadrid City (Central Spain).MethodsWe studied four types of plant communities following soil disturbance gradients: vegetation on trampled soils, roadside vegetation, annual grasslands and perennial forbs. Regarding vegetation, we studied plant composition and productivity, plant diversity, plant growth forms and functional groups. Regarding soils, we determined soil organic carbon (TOC), available nutrients, the activity of seven enzymes relating to the main macronutrient cycles, and physical properties such as bulk density (BD) and soil water‐holding capacity (WHC). We used one‐way ANOVA to determine the influence of the plant community type on both soil and vegetation variables. Canonical correspondence analysis was performed to interpret the relationships between plant species assemblages with environmental gradients.ResultsPerennial forbs showed greater biomass and developed on soils with the greatest TOC and available phosphorus. Annual grasslands displayed the highest plant diversity. Roadside vegetation developed on soils with higher phenoloxidase activity when compared to vegetation on trampled soils and annual grasslands. Vegetation on trampled soils developed on soils with lower WHC, lower beta‐glucosidase, arylamidase and phosphatase activities and higher BD when compared to perennial forbs. Plant community distribution followed gradients most significantly associated with soil organic matter content, soil compaction and nutrient cycling performance.ConclusionsWe conclude that plant communities are good indicators of ecosystem function and services which are unevenly distributed throughout urban habitats. The management in Mediterranean unmaintained urban greenspaces should be aimed at avoiding soil compaction to promote biodiversity, carbon storage and water regulation.

Phytosociological and edaphic parameters of Actaea kashmiriana assemblages in Kashmir Himalaya

Phytosociological analysis and soil physicochemical properties provide the baseline data to understand the overall vegetation composition and structure. In this study, we investigated the species composition and diversity of vegetation assemblages of an endemic plant species Actaea kashmiriana along with the edaphic parameters. We laid randomly selected sampling quadrats across five different sites in Kashmir Himalaya. We employed multiple Pearson's correlation and principal component analysis to investigate the interaction between phytosociological and edaphic parameters. The results revealed that 90 plant species are associated with A. kashmiriana, and Asteraceae, Rosaceae and Lamiaceae were the dominant families. Fragaria nubicola (36.59), Dryopteris blanfordii (34.72), Viola odorata (39.83), Galium aparine (23.70), Trifolium pratense (16.19), Cynodon dactylon (16.94), Urtica dioica (15.29) and Taraxacum officinale (14.25) showed higher Importance Value Index (IVI) and were found to be dominant in A. kashmiriana assemblages. The IVI of A. kashmiriana ranged from 11.24 to 13.76 across the study sites. We found a positive co-occurrence of A. kashmiriana with Viburnum grandiflorum, Arisaema jacquemontii, Bistorta amplexicaulis, Taraxacum officinale, Fragaria nubicola, and Urtica dioica. The soil physicochemical properties significantly correlated with the species diversity indices, with the site having nutrient-rich soils and less disturbance possessing higher species richness and diversity. The findings of our study can help in developing better strategies for effective conservation and habitat restoration of this plant species endemic to Kashmir Himalaya, with learnings for elsewhere in the world.

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.

Can vegetation be discretely classified in species-poor environments? Testing plant community concepts for vegetation monitoring on sub-Antarctic Marion Island.

The updating and rethinking of vegetation classifications is important for ecosystem monitoring in a rapidly changing world, where the distribution of vegetation is changing. The general assumption that discrete and persistent plant communities exist that can be monitored efficiently, is rarely tested before undertaking a classification. Marion Island (MI) is comprised of species-poor vegetation undergoing rapid environmental change. It presents a unique opportunity to test the ability to discretely classify species-poor vegetation with recently developed objective classification techniques and relate it to previous classifications. We classified vascular species data of 476 plots sampled across MI, using Ward hierarchical clustering, divisive analysis clustering, non-hierarchical kmeans and partitioning around medoids. Internal cluster validation was performed using silhouette widths, Dunn index, connectivity of clusters and gap statistic. Indicator species analyses were also conducted on the best performing clustering methods. We evaluated the outputs against previously classified units. Ward clustering performed the best, with the highest average silhouette width and Dunn index, as well as the lowest connectivity. The number of clusters differed amongst the clustering methods, but most validation measures, including for Ward clustering, indicated that two and three clusters are the best fit for the data. However, all classification methods produced weakly separated, highly connected clusters with low compactness and low fidelity and specificity to clusters. There was no particularly robust and effective classification outcome that could group plots into previously suggested vegetation units based on species composition alone. The relatively recent age (c. 450,000 yearsB.P.), glaciation history (last glacial maximum 34,500 yearsB.P.) and isolation of the sub-Antarctic islands may have hindered the development of strong vascular plant species assemblages with discrete boundaries. Discrete classification at the community-level using species composition may not be suitable in such species-poor environments. Species-level, rather than community-level, monitoring may thus be more appropriate in species-poor environments, aligning with continuum theory rather than community theory.

Can we simultaneously decontaminate and cultivate? An urban cherry tomato story

AbstractUrban planners are increasingly focused on integrating urban farming as a creative strategy for producing sustainable, local food in underutilized spaces, once occupied by polluting industries, in peri‐urban areas. However, before urban farming's contribution to local self‐sufficiency can be determined, it is crucial to gather quantitative data on the effectiveness of tailored strategies, including polyculture, and the suitability of different vegetables, to adequately assess the value of brownfields. This study aims to provide quantitative agronomic data on a copper‐contaminated urban garden with the dual objective of assessing its capacity for food production and mitigating the spread of soil contamination. Tomato (Solanum lycopersicum) plants were grown for one growing season in brownfield soils with different copper concentrations (up to 2000 mg kg−1), accompanied by different plant species assemblages typically used in phytoremediation (Achillea millefolium, Salix discolor, and Trifolium repens). The most successful assemblage yielded over 800 fruits per square meter with low copper concentrations (<5 mg kg−1), indicating that one square meter could satisfy the annual fresh tomato weight requirement of an average individual. Although some amendments can improve adaptability to local soils, the highest fruit‐producing assemblage consisting of S. lycopersicum, S. discolor, and T. repens also proved to be the one of the most effective for copper phytoextraction, removing over 30 g ha−1 from the contaminated soils. Overall, the data indicated that all assemblages phytostabilized copper. The quantitative results of this study provide a valuable benchmark for urban planners and researchers to implement large‐scale urban agriculture on brownfield sites.

Which regionalization scheme is the best to predict wetland plant distribution in Western Patagonia?

AbstractQuestionsGiven the current multiplicity of threats to pond biodiversity, there is a clear need to examine which environmental drivers determine the composition and distribution of species. Using wetland plants as pond biodiversity surrogates, two questions led to this work: How do wetland plant species assemblages and abundance vary across local‐ and regional‐scale classification schemes in wetlands? How does wetland plant beta‐diversity vary within these wetland classification schemes?LocationWestern Patagonia, Argentina, from 36°S to 56°S and from 73°W to 65°W.MethodsWetland plant distribution constrained by water and climatic factors was analyzed using canonical correspondence analysis. Variance partitioning analysis was performed to assess which classification scheme (phytogeographical units, wetland regions, wetland genesis and hydrogeomorphological types) better explained variation in plant composition. An IndVal analysis was also carried out to detect taxa with the highest association values (indicator taxa) for the different categories of wetland classification. Beta‐diversity was calculated to evaluate variation patterns within classification schemes.ResultsPlant distribution was mainly related to site location across the latitudinal gradient, following a decreasing pattern of air temperature from northern to southern wetlands. Variance partitioning analysis confirmed the effectiveness of a regional‐scale classification (wetland regions) in predicting plant associations, and the IndVal analysis also highlighted this classification scheme above the remainder, sustaining the highest number of indicator taxa. Wetland plant beta‐diversity patterns were explained by relatively high species turnover, with species composition showing low nestedness values.ConclusionClimate factors rather than local characteristics were the main drivers of plant distribution at the wide regional scale analyzed. Wetland region (classification based on climatic criteria) was the most effective scheme in predicting plant associations and sustaining the highest number of indicator taxa. Also, ponds located in the Patagonian Andes and those with a glacigenic origin contribute most to the regional wetland plant diversity. Therefore, these aspects should be taken directly into account in the future delineation of protected areas to increase the resilience of Patagonian wetland habitats and their associated biota, and to maintain the ecosystem services that they provide.

Does compensatory mitigation restore food webs in coastal wetlands? A terrestrial arthropod case study on the Upper Texas Coast

Compensatory wetland restoration is a critical component of holistic, ecosystem-level oil spill response strategies. An important goal of restoration is to rehabilitate food webs in impacted areas, but faunal assemblages and trophic dynamics are rarely included in post-restoration monitoring or assessments of success. Different approaches to wetland restoration, including variations in construction technique, may influence faunal recovery and trophic interactions. To explore these dynamics, we compared emergent plant communities, terrestrial arthropod assemblages, and trophic interactions in restored emergent marshes that were constructed in terrace and mound configurations and in reference areas in the Lower Neches Wildlife Management Area (Texas, United States). Plant community composition differed among all habitat types, with higher diversity on terraces and in reference marshes. Terrestrial arthropod abundance was similar among habitat types, but species composition was distinctly different among habitat types, especially at the herbivore level, where four of the eight herbivore species were found in either reference or restored sites, but not in both habitat types. Herbivores (primarily beetles and planthoppers) were more abundant than detritivores (midges and flies) in all habitat types. Predator (web-building and hunting spiders) abundance and species identity were similar among habitat types. Based on stable isotope analysis, trophic relationships differed among mounds, terraces, and reference areas. Herbivore diets were more variable at the reference sites than in either restored habitat type, aligning with higher plant diversity in reference areas. In contrast, detritivore diets were more variable at restored sites, where they were likely consuming food sources such as benthic algae or sediment organic matter. Predator diets were primarily comprised of herbivores in reference areas and detritivores in restored habitats. Overall, the restoration approaches supported abundant terrestrial arthropod assemblages, but species composition was different. In addition, trophic relationships differed between restored and reference areas, in part due to unique plant species assemblages at restored and reference sites. These results suggest that ecosystem restoration strategies that introduce geomorphological heterogeneity and plant diversity are more likely to support a diverse array of species and functions.

Why honeybees are poor pollinators of a mass-flowering plant: Experimental support for the low pollen quality hypothesis.

PremiseHoneybees dominate the flower‐visitor assemblages of many plant species, yet their efficiency in terms of the quality of pollen delivered to stigmas is largely unknown. We investigated why honeybees are poor pollinators of Aloe ferox, a self‐incompatible succulent treelet with large numbers of flowers. Honeybees are very frequent visitors to flowers of this species, yet contribute very little to seed production.MethodsWe assessed pollen loads on honeybees, studied their visitation behavior, selectively excluded birds from plants to determine direct effects of bees on pollen deposition, seed set, and ovule abortion, and used a novel “split‐pollinator” method to test whether honeybees deposit mainly low‐quality self pollen. For the latter, we captured honeybees, and with their existing pollen loads, used them to either pollinate virgin flowers on the plant on which they were caught or to pollinate virgin flowers on different plants.ResultsHoneybees cumulatively deposit as much pollen on stigmas as do birds, but our experiments showed that the pollen deposited by honeybees is mostly low‐quality self pollen that leads to substantial ovule discounting and depressed seed set.ConclusionsLack of movement among A. ferox plants during individual honeybee foraging bouts is the most likely explanation for their deposition of low‐quality self pollen on stigmas. The “split‐pollinator” method is a simple and cost‐effective technique to test the quality of pollination.

Impact of Horse Grazing on Floristic Diversity in Mediterranean Small Standing-Water Ecosystems (SWEs).

Small standing-Water Ecosystems (SWEs), despite their pivotal ecological role due to their participation in hydrogeological processes and their richness in biodiversity, seem to be often overlooked by the scientific community. In this study, the vascular plant diversity in some representative SWEs, that host a peculiar assemblage of plant and animal species, was investigated in relation to the disturbance effects of a wild horse population. A total of 50 plots, equally distributed in small and large SWEs, were surveyed and a level of disturbance was attributed to each plot. We found greater species richness in small and undisturbed SWEs, which suggests the negative impact of horse grazing on the richness of plant species in this type of habitat. Significant differences in plant assemblage were found according to the disturbance level, whereas, contrary to what was observed for species richness, no differences were detected based on their size. The diversity indices, used to evaluate the richness and diversity in these areas, recorded the highest values for small and undisturbed areas. This result highlights that the disturbance of the horse grazing plays a pivotal role in affecting the diversity and richness of species in the SWEs. These findings suggest that SWE systems should be analyzed considering these areas as unique in order to allow the conservation of the plant richness and biodiversity of the SWE systems in conjunction with the protection of horses.

How different is the forest on post-coal mine heap regarded as novel ecosystem?

Forests are the dominant terrestrial ecosystems on the Earth. During natural succession, a quite known pattern of changes occur (i.e., the process of a gradual assemblage of plant species and associated organisms best adapted to the current habitat conditions). Much less is known about novel ecosystem establishment's primary spontaneous successional mechanisms due to human agency such as post-coal mine heaps habitats. The post-coal mine heaps are sites of pure mineral substrates and constrain (e.g., temperature, acidity, drought, salinity) habitat conditions. These conditions are variable both in time and space. Regardless of all these constraints, diverse vegetation is soon spontaneously developing on these sites. A characteristic feature of the vegetation successional development on post-coal mine heaps is the emergence of non-analogous species assemblages when comparing to the natural and seminatural vegetation communities and ecosystems.This study aimed to compare the forest spontaneously developed on the mineral novel material habitat of the post-coal mining heap, with forests in the surrounding, on non-industrial habitats (located in Silesian Upland (South Poland)) in taxonomic, phylogenetic, and functional diversity at alpha (within-site) and beta (among sites) levels. The functional traits values of the recorded species composition were calculated to assess, e.g., the taxonomic alpha diversity Shannon's diversity and evenness index, Simpson index, functional richness (FRic), functional dispersion (FDis), functional divergence (FDA), and functional evenness (FEve). Rao's entropy has standardized the Biotic Novelty Index (BNI) to reflect the proportion of functional diversity contributed by novel species composition.The results revealed higher functional richness and dispersion in coniferous forests than in forests on heaps. The plots from coniferous forests and heaps were distinctly differentiated in terms of species composition. No difference occurred in functional evenness and divergence. Vegetation patches of coniferous forests had 19% higher species richness and twice higher Faith's phylogenetic diversity, while no differences in species diversity described by Shannon's diversity index have been recorded. An almost thirty times higher biological novelty index in forests on heaps than in coniferous forests patches has been recorded. The RLQ - analysis of relationships between plant traits, species composition and environmental variables revealed significant associations between EIVs and type of habitat and plant traits. The plant traits such as SLA and SM seem indifferent and do not differentiate the two studied habitats.The results showed that both understanding mechanisms by which these habitats are shaped and recognizing their biological potential and values are essential for nature conservation and management and challenge future studies.

High species turnover and low intraspecific trait variation in endemic and non‐endemic plant species assemblages on an oceanic island

AbstractQuestionsBoth species turnover and intraspecific trait variation can affect plant assemblage dynamics along environmental gradients. Here, we asked how community assemblage patterns in relation to species turnover and intraspecific variation differ between endemic and non‐endemic species. We hypothesized that endemic species show lower intraspecific variation than non‐endemic species because they tend to have high rates of in situ speciation, whereas non‐endemic species are expected to have a larger gene pool and higher phenotypic plasticity.LocationLa Palma, Canary Islands.MethodsWe established 44 sampling sites along a directional gradient of precipitation, heat load, soil nitrogen, phosphorus and pH. Along this gradient, we estimated species abundances and measured three traits (plant height, leaf area and leaf thickness) on perennial endemic and non‐endemic plant species. In total, we recorded traits for 1,223 plant individuals of 43 species. Subsequently, we calculated community‐weighted mean traits to measure the relative contribution of species turnover, intraspecific variation and their covariation along the analysed gradient.ResultsThe contribution of intraspecific variation to total variation was similar in endemic and non‐endemic assemblages. For plant height, intraspecific variation explained roughly as much variation as species turnover. For leaf area and leaf thickness, intraspecific variation explained almost no variation. Species turnover effects mainly drove trait responses along the environmental gradient, but intraspecific variation was important for responses in leaf area to precipitation.ConclusionsDespite their distinct evolutionary history, endemic and non‐endemic plant assemblages show similar patterns in species turnover and intraspecific variation. Our results indicate that species turnover is the main component of trait variation in the underlying study system. However, intraspecific variation can increase individual species’ fitness in response to precipitation. Overall, our study challenges the theory that intraspecific trait variation is more important for the establishment of non‐endemic species compared with endemic species.

The ecology, evolution and management of mast reproduction in Australian plants

Australia is home to a diverse assemblage of plant species that display marked population-level variation in inter-annual flower or seed output (i.e. masting). These include a semelparous bamboo with an estimated inter-crop period of 40–50 years, numerous iteroparous masting gymnosperms, angiosperms that include landscape-dominant eucalypts, arid-zone wattles and spinifex (Triodia spp.) grasses, and a rich selection of species that display disturbance-related forms of masting such as pyrogenic flowering and environmental prediction. Despite the prevalence of masting in the Australian flora, there has been a paucity of research on these plants. Nevertheless, from the literature available, it appears that, similar to other parts of the world, a continuum of inter-year reproductive variability exists, with a small number of species displaying extreme–high inter-annual seeding variability. From experimental studies and many anecdotal reports, most of the fitness benefits associated with masting evident overseas also operate in Australia (e.g. predator satiation, improved pollination efficiency, and environmental prediction). Additionally, some Australian masting species offer periodically important food resources for Aboriginal nations in the form of seed or fruit. These include the bunya pine (Araucaria bidwillii), members of the cycad genera Cycas and Macrozamia, spinifex (Triodia) grasses, and mulga shrubs (Acacia aneura). Key future research areas for effective conservation of Australian masting plants include (1) improved understanding of how management interventions such as burning and silvicultural thinning influence regeneration dynamics and higher-order trophic interactions, (2) further longitudinal monitoring across a range of habitats to identify other, as yet unknown, species that display reproductive intermittency, and (3) elucidation of how changes to temperature, precipitation and fire regimes under climate change will affect reproduction and regeneration dynamics of the Australian masting flora.

Determining the distributions of plant communities in subantarctic vegetation using species distribution models

Context Mapping of vegetation is important in understanding its dynamics in relation to climate change and disturbance. We investigated using species distribution models to predict plant species assemblages in a subantarctic environment where traditional image interpretation methods of vegetation mapping are limited by image availability and ability to discriminate vegetation types. Aims We test the efficacy for mapping of modelling the range and core range of common species. We also determine the relative importance of predictor variables for each of nine species. Methods We used random forest models to predict the total range and core range (>25% projected foliage cover) of nine potentially dominant plant species and determined the contributions of predictor variables to the models for each species. Key results Widespread species with extensively overlapping ranges were spatially more partitioned with modelling based on core range than with presence or absence modelling. The core range input produced a vegetation map that better approximated observed vegetation patterns than that from presence or absence data. The most important predictor variable varied between species, with elevation, distance from coast, latitude and an across island gradient (similar to longitude) being most influential. Conclusions Species distribution models using three categories (absent, <25% cover, ≥25% cover) and topographic variables derived from a digital elevation model can be used to model the distribution of vegetation assemblages in situations where presence or absence species models cannot discriminate assemblages. Implications Readily collected point location species data could be used to investigate change over time in the spatial extent of both species and vegetation types.

The Genomic Architecture of Competitive Response of Arabidopsis thaliana Is Highly Flexible Among Plurispecific Neighborhoods.

Plants are daily challenged by multiple abiotic and biotic stresses. A major biotic constraint corresponds to competition with other plant species. Although plants simultaneously interact with multiple neighboring species throughout their life cycle, there is still very limited information about the genetics of the competitive response in the context of plurispecific interactions. Using a local mapping population of Arabidopsis thaliana, we set up a genome wide association study (GWAS) to estimate the extent of genetic variation of competitive response in 12 plant species assemblages, based on three competitor species (Poa annua, Stellaria media, and Veronica arvensis). Based on five phenotypic traits, we detected strong crossing reaction norms not only between the three bispecific neighborhoods but also among the plurispecific neighborhoods. The genetic architecture of competitive response was highly dependent on the identity and the relative abundance of the neighboring species. In addition, most of the enriched biological processes underlying competitive responses largely differ among neighborhoods. While the RNA related processes might confer a broad range response toolkit for multiple traits in diverse neighborhoods, some processes, such as signaling and transport, might play a specific role in particular assemblages. Altogether, our results suggest that plants can integrate and respond to different species assemblages depending on the identity and number of each neighboring species, through a large range of candidate genes associated with diverse and unexpected processes leading to developmental and stress responses.

Paleontological inventory of Paleozoic, Late Mesozoic, and Cenozoic plant, invertebrate, and vertebrate fossil species from Big Bend National Park, Texas, USA - over a century of paleontological discovery

The extraordinary paleontological record from Big Bend National Park (BIBE), Texas chronicles nearly 120 million years of largely uninterrupted deposition through Late Cretaceous, Paleogene and Neogene time. Therefore, the park records one of the most complete and continuous fossil records of its kind in North America, if not the world. Paleontologists have collected and studied fossils from BIBE for over a century and nearly 1400 fossil species have been reported thus far. The BIBE paleontological record includes type specimens representing 44 scientifically valid species (five plants, nine invertebrates, and 30 vertebrates). Numerous other reported specimens are very likely new to science but have yet to be formally named. The present catalog presents the currently known assemblage of fossil plant, invertebrate, and vertebrate species from BIBE within a single, comprehensive record with significant references for each. This work is designed and written to be a research and resource management tool for scientists and non-scientists alike.