Increased Resource Availability Research Articles

Plant trait dissimilarity increases competitive interactions among co‐occurring plants

Abstract Plant–plant interactions, often studied in the context of plant traits, are considered crucial assembly mechanisms for plant communities and offer insights into how neighbours affect growth. Three key questions regarding these interactions have theoretical importance but limited empirical support: (1) does similarity in plant traits enhance competitive interactions among species, (2) is the “competitive environment” determined through plant traits of the resident species, and (3) do greater species diversity and niche use result in increased competition among co‐occurring species. Here we use a simple experimental design to directly test these foundational questions. In a mesocosm experiment using native grassland fragments, we investigated our questions simultaneously by manipulating trait relationships among resident and colonizing plants. To assess the net impact of neighbours on plant growth, we measured the degree of suppression experienced by focal plants compared to growth in the absence of neighbours. We further tested whether trait‐function relationships are context‐dependent by modifying available resources. Contrary to the limiting similarity hypothesis, we found that reduced overall dissimilarity mitigated neighbour‐induced growth suppression, with more negative effects occurring among dissimilar neighbours. The influence of trait dissimilarity depended on nutrient context and was stronger under increased resource availability. We found little support for the idea that specific plant traits are “functional” in creating competitive environments: no community traits (community weighted means) were associated with net neighbour effects. In contrast, resource supply significantly affected species interactions, with increased resources exacerbating negative neighbour effects on plant growth. We found that plant trait dissimilarity does function in competition but is contingent on resource context. However, trait values were not inherently competitive: traits may have physiological functions but did not function in focal plants' competitive response. We provide some of the limited data directly testing the core mechanisms of community assembly. We encourage such direct experimental tests as they are essential to building an understanding of ecological processes. Read the free Plain Language Summary for this article on the Journal blog.

Sex, moulting dynamics, and reproductive status in Atlantic Forest tanagers and their collective impact on body condition

ABSTRACT Body condition in individuals is intricately linked to behaviour, physiology, and immunity. This study investigated how seasonal factors, such as reproduction and moulting, influence the body condition of 21 tanager species in the Atlantic Forest. Utilising publicly available data, I employed phylogenetic generalised linear mixed models to dissect these influences. Notably, females with brood patches exhibited concurrent body and feather moult, suggesting simultaneous energy-costly constraints. Furthermore, females with brood patches displayed higher body condition, indicating proactive preparation or increased resource availability during breeding. Lastly, individuals moulting body feathers exhibited enhanced body condition, suggesting heightened foraging activity. These data suggest complex connections between sex, moulting, and reproductive status in tanagers in the Atlantic Forest.

Neonatal Hyperbilirubinemia Admissions Following Clinical Practice Guideline Implementation.

Treatment of neonatal hyperbilirubinemia remains one of the most common reasons for readmission following delivery. Revised clinical practice guidelines (CPGs) for the treatment of neonatal hyperbilirubinemia were published on August 5, 2022. This report describes the preliminary outcomes following implementation of the new CPGs at Tripler Army Medical Center. A retrospective chart review was performed for the 12 months prior to implementation and the 5 months post implementation. Bilirubin admissions decreased from 15.6% of total admissions during the 12 months prior to the new guidelines (69/441) to 4.1% of admissions (8/194) during the 5 months after implementation of the new guidelines (P < 0.001). This corresponds to a 74% reduction (risk ratio = 0.26, 95% confidence interval [CI] 0.13 to 0.54). The decrease in admissions was found to correlate to greater than $140,000 in annual savings. Adhering to the revised CPGs has the potential to increase resource availability at a time when nursing shortages and financial instability are impacting health care systems nationwide. No short-term adverse events were noted; however, long-term follow up will be needed.

Resource availability and herbivory alter defence-growth-reproduction trade-offs in a masting Mediterranean pine

Pairwise trade-offs among the main dimensions of life history of plants, namely growth, reproduction and defence, have been hypothesized and repeatedly tested. Experimental evidences, however, are far from conclusive, probably as a consequence of different methodological approaches, but also of an underlying multivariate complexity that is not considered in pairwise analyses. We carried out two long-term field experiments with 81 ramets clonally replicated from 6 genotypes of maritime pine (Pinus pinaster) to assess the allocation to growth, reproduction and defence in response to increased resource availability (fertilization and control treatments) and simulated herbivory (low intensity mechanical wounding, high intensity mechanical wounding, needle clipping, jasmonate application and control treatments). Fertilization increased tree growth and N and P concentration, and altered the production of resin and polyphenolics in complex ways, contingent on time and tissue. A natural event of infestation by Pissodes castaneus was more intense on fertilized trees. Fertilization increased both reproductive effort and output in terms of quantity (number of seeds) but not quality (dry weight of seeds). Needle clipping and methyl-jasmonate, but not mechanical wounding, increased the concentration of needle resin and phenols shortly after treatment, while concentrations in the phloem remain unaltered. Damage by P. castaneus did not differ across induction treatments. Generally, needle clipping had the strongest effect on reproductive variables, and mechanical wounding the mildest, with a high variability on intensity and direction of effects. Needle clipping decreased tree growth, while the rest of herbivory treatments did increase it. Complex interactions among life-history dimensions arose, showing that pairwise approaches are too simplistic for unravelling these complexities. This three-way relationship imposes new environmental and physiological constraints to the evolution and maintenance of reproductive strategies.

Trait–environment relationships depend on species life history

AbstractQuestionPredicting the functional response of vegetation to environmental variations remains highly challenging. A first reason is that trait–environment relationships result from joint intraspecific and interspecific responses. A second reason is that most plant communities host sets of species that are expected to display different environmental responses according to their ecophysiological strategies.LocationMediterranean rangeland, Larzac Plateau, France (“La Fage” INRAE experimental station: 43°55′ N, 3°05′ E).MethodsIn a Mediterranean rangeland, we tested whether changes in trait values in response to management intensification (increased resource availability and grazing intensity) differ between annuals and perennials that coexist locally. To capture the multiple facets of plant phenotypes, we studied nine traits related to carbon acquisition and conservation, plant size, water‐use efficiency, phenology and reproduction.ResultsFor most traits, we evidenced a significant interaction between environment and life history. In particular, changes in trait values were higher in perennials for leaf traits related to tissue density and growth. These differences were explained by: (a) a lower species turnover in annuals, and (b) the presence of species with more distinct trait values across environments in perennials. For most traits, these changes were not accompanied by differential intraspecific variations between annuals and perennials, which invalidates previous theoretical predictions. In addition, the contribution of intraspecific trait variation to among‐communities trait variance was higher for annuals than perennials for most traits.ConclusionAltogether, our findings highlight that changes in trait values with the environment can depend on functional groups (here, life history), which can further critically impact the assessment of the functional response of communities. They challenge the mean field approaches to communities in which trait aggregation is most often blindly applied, without considering potential different trajectories in response to environmental changes at various nested organizational levels.

Tropical forest mammal occupancy and functional diversity increase with microhabitat surface area.

Many animal-environment interactions are mediated by the physical forms of the environment, especially in tropical forests, where habitats are structurally complex and highly diverse. Higher structural complexity, measured as habitat surface area, may provide increased resource availability for animals, leading to higher animal diversity. Greater habitat surface area supports increased animal diversity in other systems, such as coral reefs and forest canopies, but it is uncertain how this relationship translates to communities of highly mobile, terrestrial mammal species inhabiting forest floors. We tested the relative importance of forest floor habitat structure, encompassing vegetation and topographic structure, in determining species occupancy and functional diversity of medium to large mammals using data from a tropical forest in the Udzungwa Mountains of Tanzania. We related species occupancies and diversity obtained from a multispecies occupancy model with ground-level habitat structure measurements obtained from a novel head-mounted active remote sensing device, the Microsoft HoloLens. We found that habitat surface area was a significant predictor of mean species occupancy and had a significant positive relationship with functional dispersion. The positive relationships indicate that surface area of tropical forest floors may play an important role in promoting mammal occupancy and functional diversity at the microhabitat scale. In particular, habitat surface area had higher mean effects on occupancy for carnivorous and social species. These results support a habitat surface area-diversity relationship on tropical forest floors for mammals.

Organic carbon enables the biotic engineering of beneficial soil structure in Profundihumic and Haplic Ferralsols

AbstractWe investigated how organic matter may, directly and indirectly, modify the porosity of Ferralsols, that is, deeply weathered soils of the tropics and subtropics. Although empirical and anecdotal evidence suggests that organic matter accumulation may increase porosity, a mechanistic understanding of the processes underlying this beneficial effect is lacking, especially so for Ferralsols. To achieve our end, we leveraged the fact that the Profundihumic qualifier of Ferralsols (PF) is distinguished from Haplic Ferralsols (HF) by both a much larger average carbon content in the first 1 m of soil depth (19 kg C m−3 in PF vs. 10 kg C m−3 in HF) and a significantly lower bulk density (1.05 ± 0.08 kg L−1 in PF vs. 1.21 ± 0.05 kg L−1 in HF). Through exhaustive modelling of carbon – bulk density relationships, we demonstrate that the lower bulk density of PF cannot be satisfactorily explained by a simple dilution effect. Rather, we found that bulk density correlated with carbon content when combined with carbon: nitrogen ratio (r2 = 0.51), black carbon content (r2 = 0.75), and Δ14C (r2 = 0.81). Total pore space was greater in PF (61 ± 3%) than in HF (55 ± 2%), but x‐ray computed tomography revealed that pore space inside soil aggregates of 4–5 mm diameter does not vary between the studied Ferralsols. We further observed nearly twice as many roots and burrows in PF compared with HF. We thus infer that the mechanism responsible for the increase in porosity is most likely an enhancement of resource availability (e.g., energy, carbon, and nutrients) for the organisms (earthworms, ants, termites, etc.) that physically displace soil particles and promote soil aggregation. As a result of increased resource availability, soil organisms can create especially the mesoscale structural soil features necessary for unrestricted water flow and rapid gas exchange. This insight paves the way for the development of land management technologies to optimize the physical shape and capacity of the soil bioreactor.

Deciduous Tundra Shrubs Shift Toward More Acquisitive Light Absorption Strategy Under Climate Change Treatments

AbstractThe effects of climate change on plants are particularly pronounced in the Arctic region. Warming relaxes the temperature and nutrients boundaries that limit tundra plant growth. Increased resource availability under future climate conditions may induce a shift from a conservative economic strategy to an acquisitive one. Following the leaf economics spectrum that hypothesizes a strategy gradient between survival, plant size and costs for the photosynthetic leaf area, light absorption of tundra plants may increase. We investigated climate change effects on light absorptance and the relationship between light absorptance (fraction of absorbed photosynthetically active radiation, FAPAR) and structural and nutritional leaf traits, performing a soil warming and surface soil fertilization experiment on two deciduous tundra shrub species. Our results show that fertilization and warming combined increase light absorptance in Arctic shrubs and that FAPAR is correlated with leaf nutrients but not with structural leaf traits. This indicates an economic strategy shift of shrubs from conservative to acquisitive induced by warming and fertilization combined. We found species‐specific differences: FAPAR was influenced by warming alone in Betula nana but not in Salix pulchra, and FAPAR was correlated with leaf phosphorus in B. nana but not in S. pulchra. We attribute this to water limitation of B. nana that generally grows in drier areas within the study site compared to S. pulchra. We conclude that FAPAR is a measure that opens up more possibilities to estimate nutritional leaf traits and nutrient cycles, plant economic strategies, and ecological feedbacks of the tundra ecosystem on broader scales.

Forest disturbances increase the body mass of two contrasting ungulates

Abstract As climate change intensifies and demand for timber rises, forest disturbances are increasing. Disturbances in forests cause an abrupt loss in canopy cover and increase resource availability on the ground, which can have manifold effects on the habitat quality of forest‐dwelling species. One pathway through which disturbances influence habitat quality is by creating edges within forests. Disturbance‐created edges differ from edges to other land cover types in that they are transient, that is, they persist only for a limited period of time until canopy closes again. While the effects of permanent edges are well‐studied in ecology, the role of transient edges remains largely unclear. Here, we investigated whether edges caused by forest disturbances affect the individual fitness of two contrasting ungulates by examining the body mass of 378,602 roe deer (Capreolus capreolus) and Alpine chamois (Rupicapra rupicapra rupicapra) yearlings collected between 1992 and 2019 in the Eastern Alps. Transient edges had a significant positive effect on the body mass of both species. The effect size was larger for chamois than for roe deer, with yearling body mass increasing by up to 0.18 kg in female chamois for each 10 m ha−1 increase in edge density. Elevation modulated the effect of edges on chamois body mass, with a weaker effect of transient edges in high‐elevation forests that are naturally more open. The effect duration of transient edges was longer for roe deer than for chamois, lasting for up to 9 years post‐disturbance. The body mass effect of transient edges created by forest disturbances was an order of magnitude stronger than the effect of permanent edges between forests and other land cover types. Synthesis and applications: Increasing forest disturbances under climate change could improve the fitness of ungulates, potentially affecting forest recovery through browsing. Managers and hunting authorities should consider the effect of disturbances and dynamically changing carrying capacity of forest landscapes more explicitly when making decisions regarding habitat management and hunting policies. Such a dynamic perspective is an important element in balancing vital ungulate populations and healthy forest ecosystems.

Repair as a circular strategy for increasing resource availability and health system resilience during a crisis

BackgroundHealthcare is a complex socio-technical system where nations regularly struggle with the misalignment between public needs and available resources. The advent of COVID-19 further exacerbated shortcomings, as evidenced by the global panic to find ventilators and beyond. However, the pandemic catalysed a successful Brazilian public-private voluntary partnership that united key industry players, industrial training centres and several volunteers, who, in the absence of a supportive government, could repair ventilators in record time, giving the health system means to succeed. ObjectivesCharacterise how a voluntary public-private partnership came into existence and codify recommendations on how it effectively used repair as a circular strategy to increase ventilator availability and bolster health system resilience. MethodsCase study using multiple data sources collected over 10 months, including national data, semi-structured interviews, daily reports, and internal communications. Sampling, research instruments, and subsequent qualitative data analysis and theory development grounded in repair strategy, resilience, and supply chain literature. ResultsA successful public-private voluntary partnership delivered 2,514 repaired ventilators, approximately 3% of the total ventilators in use in Brazil and impacting around 24,700 lives. Furthermore, effectively functioned as a first-responder bringing to hospitals approximately 500 repaired units as early as April 2020, surpassing the government's procurement and doing so just-in-time for Brazil's COVID 1st wave. More than 70 institutions and 700 professionals helped hospitals in 25 out of 27 Brazilian states. This case documents how the initiative persevered through adversity, including inadequate policies representing a widespread difficulty in enforcing the “right to repair”. Public interest summaryIn Brazil, automakers, the National Industrial Training Service and other organisations formed a voluntary and temporary alliance to repair broken ventilators that had accumulated in hospitals. This initiative took place at the beginning of the COVID-19 pandemic and returned 2,514 ventilators to hospitals, supporting patient care and partially alleviating the shortage of ventilators. This repair depended on the training of technical staff who had never worked with health equipment before. In addition to training, there was a need to share information and manuals, calibrate repaired equipment, procure spare parts, organise logistics and find funding, amongst other activities, meaning that it was a wide scale operation involving several organisations - both within and outside the health system. This research demonstrates the role of ventilator repair in making a health system more resilient in the event of a health emergency, and the urgent need to develop strategies to make repair an everyday commitment.

Arbuscular mycorrhiza changes plant facilitation patterns and increases resource use efficiency in intercropped annual plants

Arbuscular mycorrhizal fungi (AMF) play a vital role in mediating rhizosphere interactions and plant growth, especially in resource-constrained soils. However, few studies have documented the effects of AMF on plant–plant interaction patterns and resource use efficiency along stress gradients. In this study, a growth environment-controlled experiment was carried out to evaluate the effects of AMF inoculation on maize-grass pea intercropping along three phosphorus (P) and two water gradients. The data indicated that soil water and P availability determined the plant interspecific interaction pattern, and that interaction was strongly mediated by AMF inoculation. Grass pea and maize were mutually facilitated under low P and water conditions and transitioned to a new pattern, i.e., that maize was facilitated but grass pea was neutral role or facilitator with increasing resource availability. The facilitative effect was particularly significant under P- and water-deficient conditions. Moreover, the transition of the plant–plant interaction pattern was mechanically driven by improving rhizospheric phosphatase activities by 5.08–20.02 %, rhizospheric acidification and enhanced microbial activities under resource deficit conditions. Critically, AMF inoculation was observed to significantly improve rhizospheric soil P availability and microbial biomass (p < 0.05); however, it enhanced the complementary utilization of P and water and weakened interspecific competition under high-resource conditions. Therefore, AMF inoculation positively transformed the plant–plant interaction pattern along resource gradients for higher P, nitrogen and water use efficiency. This study validates the context-dependent interspecific interaction and the role of AMF in optimizing resource use in a nutrient-impoverished intercropping system.

Dynamic interplay between available resources and implementation climate across phases of implementation: a qualitative study of a VA national population health tool

BackgroundAvailable resources within an organization can determine the implementation success of an intervention. However, few studies have investigated how the required resources change over the phases of implementation. Using stakeholder interviews, we examined the changes in and interactions between available resources and implementation climate in the implementation and sustainment phases of a national implementation effort for a population health tool.MethodsWe conducted a secondary analysis of the interviews with 20 anticoagulation professionals at 17 clinical sites in the Veterans Health Administration health system about their experiences with a population health dashboard for anticoagulant management. Interview transcripts were coded using constructs from the Consolidated Framework for Implementation Research (CFIR) and according to the phase of implementation (pre-implementation, implementation, and sustainment) as defined by the VA Quality Enhancement Research Initiative (QUERI) Roadmap. We analyzed the factors that may determine successful implementation by examining the co-occurrence patterns between available resources and implementation climate across different implementation phases. To illustrate the variations in these determinants across phases, we aggregated and scored coded statements using a previously published CFIR scoring system (− 2 to + 2). Key relationships between available resources and implementation climate were identified and summarized using thematic analysis.ResultsThe resources necessary to support the successful implementation of an intervention are not static; both the quantity and types of resources shift based on the phases of the intervention. Furthermore, increased resource availability does not guarantee the sustainment of intervention success. Users need different types of support beyond the technical aspects of an intervention, and this support varies over time. Specifically, available resources in the form of technological support and social/emotional support help users establish trust in a new technological-based intervention during the implementation phase. Resources that foster and maintain collaboration between users and other stakeholders help them stay motivated during sustainment.ConclusionsOur findings highlight the dynamic nature of available resources and their impacts on the implementation climate across different phases of implementation. A better understanding of the dynamics of available resources over time from the users’ perspectives will allow the adaptation of resources to better meet the needs of the intervention stakeholders.

Temperate forest understory vegetation shifts after 40 years of conservation

Understanding how vegetation composition and diversity respond to global changes is crucial for effective ecosystem management and conservation. This study evaluated shifts in understory vegetation after 40 years of conservation within Drawa National Park (NW Poland), to check which plant communities changed the most, and whether vegetation shifts reflect global change symptoms (climate change and pollution) or natural forest dynamics. Using ordination and generalized mixed-effects linear models, we assessed changes in alpha diversity metrics, accounting for taxonomic, functional, and phylogenetic aspects within 170 quasi-permanent plots, surveyed in 1973–85 and resurveyed in 2015–19. We found an overall homogenization of forest vegetation and specific shift patterns in certain forest associations. In coniferous and nutrient-poor broadleaved forests, the overall number of species increased due to the replacement of functionally distinct or specialized species with more ubiquitous species that could exploit increased resource availability. In riparian forests and alder carrs we found either shifts from riparian forest to alder carrs or to mesic broadleaved forests. The most stable communities were fertile broadleaved forests. Our study quantified shifts in taxonomic, functional, and phylogenetic diversity after 40 years of conservation and provides important insights into the shifts in vegetation composition in temperate forest communities. In coniferous and nutrient-poor broadleaved forests we found an increase in species richness and replacement of functionally distinct or specialized species by ubiquitous species, indicating increased resource availability. Shifts between wet broadleaved forests and transition into mesic forests suggest water limitation, which can be related to climate change. The most stable were fertile broadleaved forests fluctuating due to natural stand dynamics. The findings highlight the need for ongoing monitoring and management of ecological systems to preserve their diversity and functionality in the face of global changes.

Assessing the effectiveness of disaster risk reduction strategies on the regional recovery of critical infrastructure systems

Communities depend on critical infrastructure systems to support their regular operations and future development. Destructive events, such as natural disasters, threaten to disrupt service to these systems and the communities they support. Strategies designed to reduce the impacts from disasters and other events are therefore an important consideration for community planning. At a regional level, coordination between communities supports the efficient use of resources for implementing disaster risk reduction (DRR) measures and completing post-disaster repairs to meet the needs of all residents. Coordination is challenging, however, due to the complexity of regional systems and competing stakeholder interests. This work presents a case study model of regional water, wastewater, and power systems, and demonstrates the effect of seismic hardening and increased resource availability on post-earthquake repair requirements and critical infrastructure recovery. Model results indicate that implementing DRR strategies can reduce required repair costs by over 40 percent and outage severity by approximately 50 percent for the studied sectors. Not all strategies are effective for all sectors and locations, however, so this work discusses the importance of comprehensive, coordinated, and accessible emergency planning activities to ensure that the needs of all residents are considered.

Teaching Mammalogy online: lessons learned from the COVID-19 pandemic and their application to the future

Abstract Educators of natural history have long resisted incorporating digital technology into their pedagogy for several reasons, including a perceived loss of biophilia tied to the near-ubiquitous use of digital tools. Simultaneously, a push to embrace educational technology exists for several reasons, including expanding access to educational opportunities, increasing resource availability, addressing diverse learning modalities, and approaching ‘digital natives’ in a familiar space. While the debate continues, the COVID-19 pandemic forced nearly all educators, including mammalogists, to transition rapidly to digital education and to use technology to teach students effectively. While exceedingly difficult in some respects, this pivot to remote learning provided the opportunity to identify and to use online resources to enhance student learning. I propose that this integration of technology into Mammalogy courses resulted in the development of pedagogical tools that introduced students to skills and resources that they may not have accessed in traditional learning environments and that may have enhanced the educational experience of these same students. I present the results of a survey of online mammalogy education during the pandemic, provide examples of pedagogical tools developed during the pandemic, and propose that these tools should be integrated into Mammalogy courses in the future, but not supplant traditional lab and field experiences. These online resources are particularly useful for programs with limited resources and budgets or with limited geographic access to field experiences with live mammals.

The influence of habitat properties on sex determination in cavity-nesting Hymenoptera

Unravelling the relationships between insect population dynamics and habitat properties is often complex. Established theoretical concepts, which predict an influence of available resources on sex determination, have often not been tested with quantitative field data. Cavity-nesting Hymenoptera are suitable to assess the influence of habitat properties on reproductive parameters, as haplodiploidy enables direct responses to local conditions. We hypothesize that with increasing resource availability, the population sex ratio (share of females per site), sex allocation preference per individual offspring (the probability of producing either a male or a female offspring per brood cell) and resource allocation per individual offspring will be favouring towards females. We sampled offspring of Osmia cornuta, Osmia caerulescens and Trypoxylon figulus and their resource provisions using trap nests on 30 study sites in an agricultural landscape in southwest Germany, from March to August 2020. The potential influence of resource availability, landscape variables, temperature, seasonal progression, and nesting opportunities on sex and resource provisions was tested. Population sex ratio was not related to habitat properties. Sex allocation preference in the three species, however, depended on several variables including cavity size and seasonal progression, with pronounced differences amongst species. Individual resource provisioning mainly differed between sexes, as male larvae received less provisions than female larvae. As there was no influence of resource availability, we conclude that the sex ratio of established populations was balanced at the selected study sites by available resources in the landscape. At the individual scale, sex and resource allocation were influenced in species-specific ways. As such, sex determination and resource allocation are essential life history properties of sexually reproducing organisms.

Modelling density surfaces of intraspecific classes using camera trap distance sampling

AbstractSpatially explicit densities of wildlife are important for understanding environmental drivers of populations, and density surfaces of intraspecific classes allow exploration of links between demographic ratios and environmental conditions. Although spatially explicit densities and class densities are valuable, conventional design‐based estimators remain prevalent when using camera‐trapping methods for unmarked populations.We developed a density surface model that utilized camera trap distance sampling data within a hierarchical generalized additive modelling framework. We estimated density surfaces of intraspecific classes of a common ungulate, white‐tailed deerOdocoileus virginianus, across three large management regions in Indiana, United States. We then extended simple statistical theory to test for differences in two ratios of density.Deer density was influenced by landscape fragmentation, wetlands and anthropogenic development. We documented class‐specific responses of density to availability of concealment cover, and found strong evidence that increased recruitment of young was tied to increased resource availability from anthropogenic agricultural land use. The coefficients of variation of the total density estimates within the three regions we surveyed were 0.11, 0.10 and 0.06.Synthesis and applications. Our strategy extends camera trap distance sampling and enables managers to use camera traps to better understand spatial predictors of density. Our density estimates were more precise than previous estimates from camera trap distance sampling. Population managers can use our methods to detect finer spatiotemporal changes in density or ratios of intraspecific‐class densities. Such changes in density can be linked to land use, or to management regimes on habitat and harvest limits of game species.

Temporal consistency of a facilitation cascade on shallow rocky reefs

Facilitation cascades are increasingly recognized as key drivers of biodiversity in a variety of habitats, yet their temporal variability remains poorly investigated. On shallow subtidal rocky reefs, positive interactions between the canopy-forming species, Halopithys incurva, and its epiphyte, Jania rubens, enhance the abundance and diversity of the associated mobile invertebrate assemblage. By means of a field experiment manipulating the presence of J. rubens on H. incurva plants, we investigated whether the effects of this facilitation cascade varied over time scales of months. Despite seasonal fluctuations in its biomass, J. rubens enhanced total invertebrate abundance and species richness by 64% and 45%, respectively, throughout the experiment. Our results suggest that the presence of J. rubens, likely by providing novel microhabitats and increasing resource availability, sustains invertebrate biodiversity of shallow macroalgal forests consistently between warm and cold periods. Understanding the temporal dynamics of facilitation cascades and their mechanisms can help inform management strategies targeting biodiversity conservation and restoration under current and future climates.

Divergent response and adaptation of specific leaf area to environmental change at different spatio-temporal scales jointly improve plant survival.

Specific leaf area (SLA) is one of the most important plant functional traits. It integrates multiple functions and reflects strategies of plants to obtain resources. How plants employ different strategies (e.g., through SLA) to respond to dynamic environmental conditions remains poorly understood. This study aimed to explore the spatial variation in SLA and its divergent adaptation through the lens of biogeographic patterns, evolutionary history, and short-term responses. SLA data for 5424 plant species from 76 natural communities in China were systematically measured and integrated with meta-analysis of field experiments (i.e., global warming, drought, and nitrogen addition). The mean value of SLA across all species was 21.8m2 kg-1 , ranging from 0.9 to 110.2m2 kg-1 . SLA differed among different ecosystems, temperature zones, vegetation types, and functional groups. Phylogeny had a weak effect on SLA, but plant species evolved toward higher SLA. Furthermore, SLA responded nonlinearly to environmental change. Unexpectedly, radiation was one of the main factors determining the spatial variation in SLA on a large scale. Conversely, short-term manipulative experiments showed that SLA increased with increased resource availability and tended to stabilize with treatment duration. However, different species exhibited varying response patterns. Overall, variation in long-term adaptation of SLA to environmental gradients and its short-term response to resource pulses jointly improve plant adaptability to a changing environment. Overall SLA-environment relationships should be emphasized as a multidimensional strategy for elucidating environmental change in future research.

Increases in multiple resources promote competitive ability of naturalized non-native plants

Invasion by non-native plants is frequently attributed to increased resource availability. Still, our understanding is mainly based on effects of single resources and on plants grown without competition despite the fact that plants rely on multiple resources and usually grow in competition. How multiple resources affects competition between native and non-native plants remains largely unexplored. Here, with two similar common garden experiments, one in China and one in Germany, we tested whether nutrient and light availabilities affected the competitive outcomes, in terms of biomass production, between native and naturalized non-native plants. We found that under low resource availability or with addition of only one type of resource non-natives were not more competitive than natives. However, with a joint increase of nutrients and light intensity, non-natives were more competitive than natives. Our finding indicates that addition of multiple resources could greatly reduce the niche dimensionality (i.e. number of limiting factors), favoring dominance of non-native species. It also indicates that habitats experiencing multiple global changes might be more vulnerable to plant invasion.