Persistence Of Species Research Articles

Beta‐diversity buffers fragmented landscapes against local species losses

Agricultural expansion has markedly reduced forests and reconfigured landscapes. These changes incur a well‐known detrimental impact on the biodiversity of local forest patches, but the effects on species persistence in entire landscapes comprised of multiple patches are debated. Using data from ants collected in the Amazonian deforestation arc in Brazil, we investigated how regional diversity is affected by habitat loss, fragmentation, and cattle grazing, and how species respond to deforestation both locally and regionally. We also investigated how the heterogeneity in species distribution (beta‐diversity) buffers landscapes against local diversity losses. We used hierarchical multi‐species occupancy models to estimate these effects while controlling for errors in species detection. The vast majority of the 251 ant species found in our study were negatively affected by both habitat loss and cattle at local forest patches, drastically reducing diversity at these patches compared to continuous forests. Despite local declines in diversity, however, heavily fragmented landscapes could still retain most species due to the high heterogeneity in species distribution. We found that beta‐diversity is the main component of regional diversity. Results from several studies suggest that this component is maximized when remnant primary habitats in a landscape are spread across vast areas. Although preserving local diversity may be important for the adequate functioning of the ecosystem locally, our results indicate that the maintenance of many small forest patches in a landscape can buffer regional biodiversity against local species losses. Our results suggest that even small forest remnants in otherwise deforested landscapes can collectively prevent most regional‐scale species extirpations, and therefore also merit conservation efforts.

A trade-off between leaf hydraulic efficiency and safety across three xerophytic species in response to increased rock fragment content.

Limited information is available on the variation of plant leaf hydraulic traits in relation to soil rock fragment content (RFC), particularly for xerophytes native to rocky mountain areas. In this study, we conducted a field experiment with four gradients of RFC (0, 25, 50 and 75% ν ν-1) on three different xerophytic species (Sophora davidii, Cotinus szechuanensis and Bauhinia brachycarpa). We measured predawn and midday leaf water potential (Ψleaf), leaf hydraulic conductance (Kleaf), Ψleaf induced 50% loss of Kleaf (P50), pressure-volume curve traits and leaf structure. A consistent response of hydraulic traits to increased RFC was observed in three species. Kleaf showed a decrease, whereas P50 and turgor loss point (Ψtlp) became increasingly negative with increasing RFC. Thus, a clear trade-off between hydraulic efficiency and safety was observed in the xerophytic species. In all three species, the reduction in Kleaf was associated with an increase in leaf mass per area. In S. davidii, alterations in Kleaf and P50 were driven by leaf vein density (VLA) and Ψtlp. In C. szechuanensis, Ψtlp and VLA drove the changes in Kleaf and P50, respectively. In B. brachycarpa, changes in P50 were driven by VLA, whereas changes in both Kleaf and P50 were simultaneously influenced by Ψtlp. Our findings suggest that adaptation to increased rockiness necessarily implies a trade-off between leaf hydraulic efficiency and safety in xerophytic species. Additionally, the trade-off between leaf hydraulic efficiency and safety among xerophytic species is likely to result from processes occurring in the xylem and the outside-xylem hydraulic pathways. These findings contribute to a better understanding of the survival strategies and mechanisms of xerophytes in rocky soils, and provide a theoretical basis for the persistence of xerophytic species in areas with stony substrates.

From the mountains to the sea: Rethinking Mediterranean glacial refugia as dynamic entities

AbstractAimGlacial refugia are areas of primary importance for the evolution and conservation of biodiversity. Yet, their geographic location remains loosely defined even in intensively studied areas, preventing a thorough understanding of their role in the spatiotemporal biodiversity dynamics. With this study, we aim to locate the major glacial refugia within the biodiversity hotspot of the Italian peninsula, to understand the processes that warranted the long‐term persistence of biodiversity in the face of climate changes.LocationItalian peninsula.TaxonTerrestrial vertebrates.MethodsWe calibrated species distribution models (SDM) for 22 lineages of terrestrial vertebrates endemic to the Italian peninsula and projected the SDMs to the last‐glacial maximum conditions. Then, we combined single‐lineage projections to investigate the location and spatiotemporal dynamics of multi‐species glacial refugia.ResultsMulti‐species refugia were mostly found in coastal areas that have been flooded by the post‐glacial marine transgressions, and that are currently below the sea level. Indeed, we identified six major areas acting as glacial refugia, mainly located outside the current coastline in the southern part of the peninsula and along the western coast. These areas were close to previously inferred locations of glacial refugia and genetic diversity hotspots, but none coincided with them.ConclusionsResults from this study outline glacial refugia as highly dynamic units. Most of the identified refugial areas have been lost by post‐glacial sea‐level rise. Accordingly, species persistence through the Late Pleistocene was not granted by long‐term environmental stability, but by the opportunity to shift species' distributions along altitudinal gradients, following changes in climate and habitat suitability. Notably, our results decouple glacial refugia from hotspots of genetic diversity. Thus, the current location of a hotspot should not be taken as evidence for the occurrence of a glacial refugium in that location—even though a refugium is likely to be located somewhere nearby.

Crop phenology reshapes the food‐safety landscape for roe deer in an agroecosystem

Abstract Understanding the behavioural adjustments of wildlife in anthropized landscapes is key for promoting sustainable human–wildlife coexistence. Little is known, however, about how synanthropic species navigate spatio‐temporal variation in the availability of food and cover that are shaped by human practices such as agriculture. Animal habitat use is predominantly driven by spatial and temporal variations in food and cover, as individuals respond to fluctuations in the trade‐off between food acquisition and risk avoidance. In agroecosystems, the availability of high‐quality forage and cover is dependent on agricultural practices (e.g., harvesting) and crop phenology, providing an ideal opportunity to evaluate how wildlife adjust their behaviour in a heterogeneous human‐dominated landscape. We investigated the influence of crop phenology on the behaviour of European roe deer (Capreolus capreolus) to infer the functional roles of crop types in the food‐cover landscape. We analysed the habitat selection and activity patterns of 105 GPS‐collared adult female roe deer using a unique data set combining field‐specific land cover data, region‐specific estimates of crop phenology and weekly harvesting data for three common crops in a French agroecosystem. We found very distinct habitat selection and activity patterns according to crop type, phenological stage and time of day. Wheat and artificial meadows were strongly selected at night‐time during the early and post‐harvest stages only, when roe deer were highly active, suggestive of feeding activity. On the contrary, roe deer strongly selected maize during the day when it was high enough to provide cover, when they were less active, indicating that it was primarily used for refuge. These patterns depended on the availability of more ‘natural’ cover, suggesting that mature maize may substitute for ‘natural’ cover when the latter is scarce. Synthesis and application: Our work highlights the importance of behavioural plasticity and habitat complementation in the persistence of this synanthropic species in agroecosystems. This behavioural adjustment may buffer the consequences of the reduction in natural habitats that accompanies intensification of agricultural production and has implications for understanding how agricultural practices shape the food‐safety trade‐off of wildlife living in these highly modified landscapes.

Biological invasions in intermittent rivers and streams: current knowledge, and future frontiers

Intermittent rivers and ephemeral streams (IRES) have been overlooked in invasion science as the characteristic drying - wetting regimes are assumed to be a barrier to invasion processes. Flow contraction/cessation limits the persistence and success of water-dependent invasive alien species (IAS) in most IRES, while flash floods may restrict limnophilic and strictly terrestrial ones. However, IRES are subject to multiple anthropogenic stressors that could ultimately favour the arrival and spread of IAS and their mosaic of dynamic habitats may theoretically support both terrestrial and aquatic IAS. Successful IAS are characterised by adaptations, traits and life histories which facilitate rapid, opportunistic exploitation of habitats and resources. Here, the potential invasibility of IRES is discussed along with a summary of current knowledge gaps, examples and challenges across different continents. IAS in IRES should be considered a cause for concern but also an intriguing study system to understand the mechanics of biological invasions under global change.

A botanical oasis rather than a biological desert: Rediscoveries, new species and new records in a tropical city

Societal Impact StatementCities present a unique challenge for conservation. While overall native biodiversity is reduced, remnant habitats in the urban matrix can be important refugia for native and endemic species. This study reviews the rediscovery of 173 presumed nationally extinct plant taxa and discovery of 155 new native plant records, including 22 new to science and five endemics, in the botanically densely‐collected tropical city‐state of Singapore. The findings of this study indicate that plant rediscoveries and new discoveries are still possible in cities and urban areas with remaining fragments of original forest reserved for species protection, and investment in comprehensive botanical surveys and taxonomic research.Summary The conservation of native species‐dominated forest fragments and investment into botanical surveys and taxonomic research have enabled the rediscovery of presumed nationally extinct plant taxa and discovery of new native plant records in the tropical city‐state of Singapore. We compared national plant checklists of 2009, 2022, and the national Red Data Book (third edition in press) to enumerate rediscovered and newly discovered native vascular plant taxa in the last 14 years. We examined if these were from taxonomic specialist redetermination of only pre‐existing specimens or newly collected from field surveys, and if they were from particular sites and vegetation types, disproportionately represented by certain life forms and families, and predominantly threatened. We documented 173 rediscoveries and 155 new records after 2009, including 22 new to science and five endemics. Most rediscoveries were newly collected from field surveys, but most new records resulted from redetermination of pre‐existing specimens. Native species‐dominated forest fragments were the most important sites for the first collection of new records or first re‐collection of rediscoveries. Trees and climbers were well‐represented among the rediscoveries and new records. Epiphytes were significantly under‐represented compared to their proportion in the presumed nationally extinct flora. Most rediscoveries and new records are nationally Critically Endangered but regionally and globally not assessed. Our findings indicate hope for the persistence of rare native plant species and opportunities for conservation in cities.

Tall fescue tiller survival over summer in a subtropical environment: The role of the size and depth of root systems

AbstractPasture persistence is a key determinant of the economic and environmental performance of pastoral animal production systems. Large and deep root systems that help resist summer water stress have been proposed as a relevant trait for vegetative persistence of perennial temperate forage species growing in subtropical climates or under future climatically challenging scenarios. In a previous study [Jauregui et al., 2017. Persistence of tall fescue in a subtropical environment: Tiller survival over summer in response to flowering control and nitrogen supply. Grass and Forage Science 72, 454–466] we have shown that nitrogen fertilization and grazing management aimed at ‘control flowering’ increased the survival of tall fescue tillers during harsh summers in Uruguay (lat. 32°S). Here we assessed: (i) to what extent tiller survival is mediated by root system size in spring and (ii) what consequences tiller survival entails for root mass, depth and morphology the following autumn. In two field experiments, significant increases in tiller survival in response to nitrogen fertilization and grazing management (+60% and +80% in 2011/12 and 2012/13, respectively) were not related to concomitant effects on the size or depth of the root system in spring (p > .10). Even when six‐fold within‐treatment variation in root mass was observed, within‐treatment variation in summer tiller survival was little affected (<15%, p = .08). In turn, differences in tiller survival over summer affected little root system characteristics the following autumn. Therefore, we found scant support for the hypothesis that large and deep root systems contribute to survival of tall fescue tillers in this subtropical humid climate. Except for soils with less than 30 mm of plant available water holding capacity, summer water deficits did not induce severe tiller mortality in tall fescue in this climate.

Metapopulation models using landscape connectivity can better reflect landscape heterogeneity

Forest fragmentation due to urban development has a significant impact on species persistence, necessitating a metapopulation theory approach considering landscape structure and patch-based impact assessments. In this study, we propose a method that applies landscape connectivity and incidence function models (IFM) to a species distribution model to represent the persistence of metapopulations by considering landscape structure (IFM-LCONS). The proposed approach was used to understand changes in leopard cat (Prionailurus bengalensis) occupancy patterns resulting from urban development considering landscape and patch structure. The impact on changes in occupancy owing to urban development was better reflected by patch area (R2 = 0.5031, R2 = 0.1642) and quality (R2 = 0.5142, R2 = 0.1042). Notably, the IFM-LCONS showed an increasing occupancy at a connectivity value of 500, whereas the IFM indicated the opposite. These results highlight that the here proposed approach allows for a more thorough consideration of the impact of urban development on landscape and structural aspects with respect to endangered and rare species, which can be used for conservation planning.

Soil microbiome feedbacks during disturbance-driven forest ecosystem conversion.

Disturbances cause rapid changes to forests, with different disturbance types and severities creating unique ecosystem trajectories that can impact the underlying soil microbiome. Pile burning-the combustion of logging residue on the forest floor-is a common fuel reduction practice that can have impacts on forest soils analogous to those following high-severity wildfire. Further, pile burning following clear-cut harvesting can create persistent openings dominated by nonwoody plants surrounded by dense regenerating conifer forest. A paired 60-year chronosequence of burn scar openings and surrounding regenerating forest after clear-cut harvesting provides a unique opportunity to assess whether belowground microbial processes mirror aboveground vegetation during disturbance-induced ecosystem shifts. Soil ectomycorrhizal fungal diversity was reduced the first decade after pile burning, which could explain poor tree seedling establishment and subsequent persistence of herbaceous species within the openings. Fine-scale changes in the soil microbiome mirrored aboveground shifts in vegetation, with short-term changes to microbial carbon cycling functions resembling a postfire microbiome (e.g. enrichment of aromatic degradation genes) and respiration in burn scars decoupled from substrate quantity and quality. Broadly, however, soil microbiome composition and function within burn scar soils converged with that of the surrounding regenerating forest six decades after the disturbances, indicating potential microbial resilience that was disconnected from aboveground vegetation shifts. This work begins to unravel the belowground microbial processes that underlie disturbance-induced ecosystem changes, which are increasing in frequency tied to climate change.

Structural Variations and Rearrangements in Bacterial Type II Toxin-Antitoxin Systems.

Bacteria encode a wide range of survival and immunity systems, including CRISPR-Cas, restriction-modification systems, and toxin-antitoxin systems involved in defence against bacteriophages, as well as survival during challenging growth conditions or exposure to antibiotics. Toxin-antitoxin (TA) systems are small two- or three-gene cassettes consisting of a metabolic regulator (the "toxin") and its associated antidote (the "antitoxin"), which also often functions as a transcriptional regulator. TA systems are widespread in the genomes of pathogens but are also present in commensal bacterial species and on plasmids. For mobile elements such as plasmids, TA systems play a role in maintenance, and increasing evidence now points to roles of chromosomal toxin-antitoxin systems in anti-phage defence. Moreover, the widespread occurrence of toxin-antitoxin systems in the genomes of pathogens has been suggested to relate to survival during host infection as well as in persistence during antibiotic treatment. Upon repeated exposure to antibiotics, TA systems have been shown to acquire point mutations as well as more dramatic rearrangements such as in-frame deletions with potential relevance for bacterial survival and pathogenesis. In this review, we present an overview of the known functional and structural consequences of mutations and rearrangements arising in bacterial toxin-antitoxin systems and discuss their relevance for survival and persistence of pathogenic species.

Bumble Bee Watch community science program increases scientific understanding of an important pollinator group across Canada and the USA.

In a time of increasing threats to bumble bees (Hymenoptera: Apidae: Bombus), it is important to understand their ecology and distribution. As experts are limited in resources to conduct field surveys, there is potential for community scientists to help. The Bumble Bee Watch (BBW) community science program involves volunteers taking photos of bumble bees in Canada and the USA and submitting them, along with geographic and optional plant information, to a website or through an app. Taxon experts then verify the bee species identification. The Bumble Bees of North America database (BBNA) stores data (no photographs) collected and identified by more traditional scientific methods over the same range. Here we compared BBW data to BBNA data over all years and just 2010-2020 to understand the scientific contribution of community scientists to the state of the knowledge about native bumble bees. We found that BBW had similar geographic and species coverage as BBNA. It had records from all 63 provinces, states, and territories where bumble bees occur (including four more than BBNA in 2010-2020), and represented 41 of the 48 species in BBNA (with ten more species than BBNA in 2010-2020). While BBW contributed only 8.50% of records overall, it contributed 25.06% of all records over 2010-2020. BBW confirmed the persistence of species and identified new locations of species, both inside and outside of the previously known extent of occurrences. BBW also contributed a wealth of ecological information, such as unique plant genera and species data for almost all the bee species. Thus, while BBW had fewer bee records than the BBNA database overall, it helped to fill in data gaps and provided novel information, complementing the traditional methods. This community science program is valuable in helping to inform conservation management for bumble bee species.

Microgeographic variation in demography and thermal regimes stabilize regional abundance of a widespread freshwater fish.

Predicting the persistence of species under climate change is an increasingly important objective in ecological research and management. However, biotic and abiotic heterogeneity can drive asynchrony in population responses at small spatial scales, complicating species-level assessments. For widely distributed species consisting of many fragmented populations, such as brook trout (Salvelinus fontinalis), understanding the drivers of asynchrony in population dynamics can improve the predictions of range-wide climate impacts. We analyzed the demographic time series from mark-recapture surveys of 11 natural brook trout populations in eastern Canada over 13 years to examine the extent, drivers, and consequences of fine-scale population variation. The focal populations were genetically differentiated, occupied a small area (~25 km2 ) with few human impacts, and experienced similar climate conditions. Recruitment was highly asynchronous, weakly related to climate variables and showed population-specific relationships with other demographic processes, generating diverse population dynamics. In contrast, individual growth was mostly synchronized among populations and driven by a shared positive relationship with stream temperature. Outputs from population-specific models were unrelated to four of the five hypothesized drivers (recruitment, growth, reproductive success, phylogenetic distance), but variation in groundwater inputs strongly influenced stream temperature regimes and stock-recruitment relationships. Finally, population asynchrony generated a portfolio effect that stabilized regional species abundance. Our results demonstrated that population demographics and habitat diversity at microgeographic scales can play a significant role in moderating species responses to climate change. Moreover, we suggest that the absence of human activities within study streams preserved natural habitat variation and contributed to asynchrony in brook trout abundance, while the small study area eased monitoring and increased the likelihood of detecting asynchrony. Therefore, anthropogenic habitat degradation, landscape context, and spatial scale must be considered when developing management strategies to monitor and maintain populations that are diverse, stable, and resilient to climate change.

Behavioral plasticity during acute heat stress: heat hardening increases the expression of boldness

Climate change is creating novel thermal environments via rising temperatures and increased frequency of severe weather events. Short-term phenotypic adjustments, i.e., phenotypic plasticity, may facilitate species persistence during adverse environmental conditions. A plastic response that increases thermal tolerance is heat hardening, which buffers organisms from extreme heat and may enhance short term survival. However, heat hardening responses may incur a cost with concomitant decreases in thermal preference and physiological performance. Thus, phenotypic shifts accompanying a hardening response may be maladaptive in warming climates. Understanding how heat hardening influences other traits associated with fitness and survival will clarify its potential as an adaptive response to altered thermal niches. Here, we studied the effects of heat hardening on boldness behavior in the color polymorphic tree lizard, Urosaurus ornatus. Boldness in lizards influences traits such as territory maintenance, mating success, and survivorship and is repeatable in U. ornatus. We found that when lizards underwent a heat hardening response, boldness expression significantly increased. This trend was driven by males. Bolder individuals also exhibited lower field active body temperatures. This behavioral response to heat hardening may increase resource holding potential and territoriality in stressful environments but may also increase predation risk. This study highlights the need to detail associated phenotypic shifts with stress responses to fully understand their adaptive potential in rapidly changing environments.

Apomixis goes a long way: Genetic evidence of persistence and long‐distance seed dispersal in an ancient landscape

AbstractAimApomixis is a widespread trait in extreme environments worldwide, yet phylogeographical studies for species exhibiting these complex reproductive systems are still limited to temperate zones in the Northern Hemisphere. Through analyses of a combination of adult plants and seedlings, and nuclear and chloroplast DNA, we assessed the contemporary genetic outcomes of apomixis and phylogeographical patterns in an arid unglaciated landscape to understand the evolutionary trajectory of apomictic species.LocationPilbara bioregion, north‐western Australia.TaxonSenna glutinosa subsp. glutinosa.Materials and MethodsSpatial patterns of genetic diversity and differentiation in three chloroplast regions and 17 nuclear microsatellite markers were evaluated in 480 plants from 20 populations of S. glutinosa subsp. glutinosa across the Pilbara bioregion. We also germinated and genotyped seed for a progeny analysis to quantify polyembryony and the relative frequency of asexual versus sexual reproduction.ResultsWe found frequent polyembryony and a high proportion of asexual offspring (84.56%), resulting in low within‐population genotypic diversity. The nuclear dataset identified 72 multilocus lineages (MLLs) with moderate pairwise population genetic fixation and low differentiation among populations with no geographically structured genetic clustering. Chloroplast DNA showed high haplotype diversity and a widespread distribution of haplotypes. Only one peripheral population presented a single unique haplotype and MLL.Main ConclusionsAnalysis of this woody perennial in an arid landscape shows the influence of apomixis on genetic patterns and species persistence. Haplotype diversity was indicative of long‐term persistence within the ancient Pilbara region. Widespread distribution of haplotypes and sharing of several nuclear MLLs among distant populations indicated extensive seed dispersal throughout the study area. The combination of polyploidy, facultative apomixis and extensive seed dispersal maintains genetic variability within local populations and promotes the spread of advantageous genotypes across wide geographical distances. Therefore, apomixis, rather than an evolutionary ‘dead‐end’, can be regarded as a mechanism facilitating evolutionary success of apomictic species in extreme and complex environments.

Negative plant-soil feedbacks disproportionally affect dominant plants, facilitating coexistence in plant communities

Plant-soil feedbacks (PSFs) are suggested to be major drivers of plant species coexistence and exotic invasions in natural plant communities, where species with more positive PSFs are thought to be more abundant in communities. Most evidence for this comes from mesocosm experiments with single species, but whether the results are transposable to diverse plant communities is mostly not verified and remains debated. We performed a combined monoculture and community experiment to test whether PSFs in monocultures predict PSFs in communities, and to infer the role of PSFs in invasive plant success. We found that (1) PSFs from monocultures were poor predictors for PSFs in plant communities, (2) competitive strength of invasive species did not consistently depend on PSF, and (3) dominant species experienced a significantly stronger negative PSFs than non-dominant species when grown in community. Hence, PSFs of plant species in monocultures seem less predictive for their abundance in plant communities or for invasibility than previously assumed. Nevertheless, PSF—and particularly negative PSF—seems indeed a major driver of plant species coexistence, with a strong species-specific pathogenic effect on dominant plants facilitating the persistence of rare species.

Effects of the forests-agriculture conversion on the availability and diversity of forest products in a neotropical rainforest region

Tropical rainforests offer a diverse array of real or potential forest products (FP). However, the ongoing conversion of these forests to agriculture raises concerns about the future availability and sustainability of FP. In this study, we examined the changes in availability (tree density and above-ground biomass) and species richness of native trees, recognized by local communities as sources of FP, with the forest-to-agriculture conversion in a Mesoamerican tropical rainforest region. Specifically, we tested hypotheses on whether species with FP had a higher, equal, or lower reduction in the availability, diversity, and probability of persistence than species without FP with the forest conversion. We interviewed landowners to identify tree species with FP and documented management practices and regulations for using these species. In fourteen 1 km2 landscapes, encompassing the entire range of forest-to-agriculture conversion (from 0 % to ∼100 % old-growth forest cover), we analyzed changes in the availability and richness of species with and without FP. In each landscape, we randomly established 30 plots (each 706.8 m2, totaling 420 plots and 29.7 ha sampling area) covered by old-growth forest, secondary forest, or agricultural fields (mostly cattle pastures). Over four years, we surveyed all trees with a diameter at breast height ≥ 10 cm in these plots. With the forest conversion, assemblages of tree species with FP exhibited a higher reduction in aboveground biomass than species without FP. However, assemblages of species with FP exhibited a significantly lower reduction in abundance, species richness, and a higher probability of persistence than assemblages of species without FP. Furthermore, we found evidence of implementing forest management practices favoring the preservation of species with FP in agricultural lands. Thus, we conclude that people intentionally foster the persistence of valuable species in their agricultural fields, which could have important implications for the structure and composition of future regenerating forests on abandoned agricultural lands. In the long term, this might lead to an overabundance of locally valuable species, as observed in old-growth tropical rainforests that native people ancestrally managed.

Extensive and Continuing Loss of Seagrasses in Florida's Big Bend (USA).

Florida's Big Bend in the northeastern Gulf of Mexico contains the second-largest contiguous seagrass meadow in the continental United States, providing numerous ecosystem functions and services, including carbon cycling and storage. We present 21 years of mapping data and 13 years of annual in-water monitoring that reveal extensive declines in area, species frequency of occurrence (FO), and percent cover of seagrass. Seagrass area declined by 15% to 85,170 ha in 2022. Subregions in the southern Big Bend experienced extensive seagrass losses of 90-100%. North of the Steinhatchee River, the Northern Big Bend contained 85% of the total seagrass area and experienced losses of only 8.4%. The FO of seagrass and bare quadrats exhibited similar trends to areal coverage. The lowest FO along with complete loss of species was observed near the mouth of the Suwannee River. At a distance from the Suwannee River, FO also declined, but no species were lost. In the remainder of the Big Bend, FO remained stable except for short-term reductions in 2013-2014, which were likely related to anomalously high runoff from rainfall and tropical storm activity. Mean percent cover, however, declined throughout Big Bend, reaching minimal levels in 2014, with little to no recovery through 2019. The persistence of low percent cover may increase vulnerability of beds to continuing areal losses, but the persistence of seagrass species at a distance from the Suwannee River mouth may allow recovery if environmental conditions improve.

Traffic and weather influence on small wildlife carcass persistence time on roads

The rapidly expanding road network threatens the persistence of many terrestrial species through mortality associated with wildlife-vehicle collisions. Roadkill monitoring under-estimate actual collision numbers as the time during which roadkill carcasses remain visible on the road is often shorter than the frequency of road monitoring. By placing passerine and amphibian carcasses on stretches of roads we surveyed every 2 h, we fine-tuned existing persistence estimates for these species. The time for half of the carcasses to disappear was less than 30 min for birds and 1–18 h for amphibians depending on the volume of traffic, which is much shorter than previous estimates. We show the implications of our results by performing roadkill surveys on common toads 3 h after the window of reproductive migration, showing roadkill is under-estimated by half, and by estimating from citizen-science data that passerine collisions could be as high as 10 individuals.km-2.year-1 in south-eastern France.

Learning Progression of Students’ Reasoning about Life Cycles

This study explored elementary students’ reasoning about the life cycles of various organisms, including insects and amphibians. The study took place in a private school in Lebanon with 24 fifth-grade students. Students participated in a life cycle unit with pre and post-written assessments about what they learned and interviews to help determine their reasoning about life cycles. Using our findings, we suggest a learning progression (LP) approach to guide students over time in their learning about life cycles and their importance for species persistence within an ecosystem. Two LPs were developed from this study: Reasoning about the cyclic nature of life and comparison of life cycle stages. Overall, students improved their understanding of the cyclical nature of life, but comparing organisms’ structures, stages, and life cycles proved to be more challenging. These LPs have direct implications for elementary instruction about life cycles, organisms, and species.

Edaphic conditions affect plant life‐history trait syndromes in a tropical ancient biodiverse ecosystem

AbstractA functional approach to understand natural plant communities helps elucidate the dynamics of environmental filters and community assembly. Species classification into functional groups allows the translation of ecological complexity into simplified and applicable knowledge. Here, we developed a plant functional type (PFT) system to investigate whether functional structure (PFT composition and abundance) of plant communities varies between substrate types and plant physiognomies in an old climatically buffered infertile landscape (OCBIL), namely Brazilian campo rupestre. We sampled the herbaceous and shrubby vegetation and collected soil variables in four different plant physiognomies growing in quartzitic and ferruginous substrates. We classified the sampled species according to life‐history traits related to species persistence, reproduction, and biological interactions. Functional dissimilarity among plant physiognomies and the two substrate types and the role of soil factors affecting the dissimilarities were assessed. Pollination and seed dispersal syndromes, mycorrhizal association, and reproductive phenology were the main traits defining the PFTs. We found distinct functional structure between plant communities of different substrates and physiognomies, with a marked influence of chemical and physical soil factors. Also, we defined main PFTs profiles for each physiognomy, identifying core PFTs with basic combinations of traits, common to all or almost all physiognomies. The functional perspective proposed by this study provides applicable knowledge to the restoration and conservation of campo rupestre ecosystem, reinforcing the importance of habitat heterogeneity for maintaining its functioning.