Range Boundaries Research Articles

A canonical metacommunity structure over 3 decades: ecologically consistent but spatially dynamic patterns in a hurricane-prone montane forest.

The Anthropocene is a time of rapid change induced by human activities, including pulse and press disturbances that affect the species composition of local communities and connectivity among them, giving rise to spatiotemporal dynamics at multiple scales. We evaluate effects of global warming and repeated intense hurricanes on gastropod metacommunities in montane tropical rainforests of Puerto Rico for each of 28 consecutive years. Specifically, we quantified metacommunity structure each year; assessed effects of global warming, hurricane-induced disturbance, and secondary succession on interannual variation in metacommunity structure; and evaluated legacies of previous land use on metacommunity structure. Gastropods were sampled annually during a 28-year period characterized by disturbance and succession associated with 3 major hurricanes (Hurricanes Hugo, Georges, and Maria). For each year, we evaluated coherence (the extent to which the environmental distributions of species are uninterrupted along a common latent environmental gradient), species range turnover, and species range boundary clumping; and conducted co-occurrence analyses for each pair of species. We used generalized linear mixed-effects model to evaluate long-term responses of the metacommunity to aspects of global warming and disturbance. Metacommunity structure was remarkably stable, with consistent patterns of species co-occurrence. Disturbance, warming, and successional stage had little effect on metacommunity structure. Despite great temporal variation in environmental conditions, groups of species tracked their niche through space and time to maintain the same general structure. Consequently, metacommunity structure was highly resistant and resilient to multiple disturbances, even those that greatly altered forest structure.

Differential responses of trailing-edge populations of a foundation alga to thermal stress

ABSTRACT Populations within the same species range edge may experience contrasting local conditions and exhibit diverse levels of environmental tolerance. This heterogeneity within a range boundary has seldom been considered in studies forecasting the impact of anthropogenic habitat alteration and climate change on species distributions. Moreover, any ecological prediction under changing environmental conditions requires a good understanding of the combined responses of organisms to multiple stressors, in particular the effects on key life cycle stages of species. The intertidal seaweed Fucus serratus is a dominant species on northern Atlantic shores and whose southern limit is in the NW Iberian Peninsula. We examined how early developmental stages of southern-edge populations of this foundation alga responded to the combined effects of environmental stressors, including salinity and aerial and seawater temperature. Four populations from two different areas of the NW Iberian coast were considered: two populations from open shores on the northern coast and two populations from the western rias on the Atlantic coast. The study findings revealed inter-population variability in the response to heat stress, with greater survival of germlings from the northern populations than those from western rias. Environmental conditions are still more benign within western rias, under the influence of strong summer upwelling events. The results also suggest the key role of aerial thermal stress in determining the southern limit of distribution of the target species. The future of these heterogeneous edge populations from NW Iberian Peninsula depends on trends in climate change and the ability of populations to cope with these. Environmental changes may already be occurring at rates that exceed the plastic and adaptive potential of edge populations in N Spain, while the future of western rias as climate refugia for this and other foundation alga is also uncertain.

Emergent features of species: existence between populations and communities

The key block of tasks in defining species as a phenomenon, as a concept, and as a category — its emergent features, is considered. These include 5 systems of features, such as 1) diagnosis (primarily morphological, including unique apomorphies); 2) genotype in the broadest sense (including karyotype); 3) system of reproduction and protection of the gene pool from mixing with foreign forms (reproductive isolation); 4) geographical range (including type habitats and distribution limits); 5) system of variability (including the presence and features of age-related changes, sexual differences, and trends in geographical variation). There is evidence that species as a reality is characterized by the properties of "repeating structures". To the latter the author includes the following six: 1) limited volumes of species composition of communities; 2) limited body-size rows of guilds; 3) parallelisms and the phenomenon of isomorphism; 4) limited number of ecotypes and the phenomenon of vicariates; 5) homeomorphies and restrictions of morphological types; 6) synperates as overlaps of range boundaries. Areas of non-alternative application of the concept of "species", including red lists, checklists, descriptions of unique parts of communities (endemics, rarities, etc.), and objects of economic value are given.

Spatial Gaussian processes improve multi‐species occupancy models when range boundaries are uncertain and nonoverlapping

Abstract Species distribution models enable practitioners to analyze large datasets of encounter records and make predictions about species occurrence at unsurveyed locations. In omnibus surveys that record data on multiple species simultaneously, species ranges are often nonoverlapping and misaligned with the administrative unit defining the spatial domain of interest (e.g., a state or province). Consequently, some species display differentially restricted extents within a study area. Assuming hard boundaries based on expert opinion or published range maps to restrict species occurrence predictions implies a false sense of certainty in model‐based inferences. We propose a multi‐species occupancy model with a spatial Gaussian process on site‐specific effects for each species as a model‐based solution. Specifying informative Bayesian hyperpriors on the spatial hyperparameters encapsulates broad‐scale correlation among site occupancy probabilities for each species. We fit this model to acoustic detection/nondetection data collected with autonomous recording units during summer of 2016–2019 throughout Oregon and Washington, USA, on 15 bat species. We found vast improvements in spatial predictions of spotted bat (Euderma maculatum), canyon bat (Parastrellus hesperus), and Brazilian free‐tailed bat (Tadarida brasiliensis) when the available environmental predictors were insufficient for characterizing their restricted ranges within the region. In contrast, widespread species (Lasionycteris noctivagans, Myotis californicus, Myotis evotis, Myotis volans) were appropriately modeled using only environmental predictors, such as percentage forest cover and cliff and canyon cover. Utilizing spatial Gaussian processes within a community or multi‐species model incorporates uncertainty in range boundaries and allows for simultaneous predictions for the entire faunal assemblage even if species have nonoverlapping or restricted ranges within a spatial domain of interest. Such modeling improvements are essential if species distribution models are to accurately inform monitoring, species recovery plans, and other conservation efforts.

Colonizations cause diversification of host preferences: A mechanism explaining increased generalization at range boundaries expanding under climate change.

As species' poleward range limits expand under climate change, generalists are expected to be better colonists than specialists, extending their ranges faster. This effect of specialization on range shifts has been shown, but so has the reverse cause-effect: in a global meta-analysis of butterfly diets, it was range expansions themselves that caused increases in population-level diet breadth. What could drive this unexpected process? We provide a novel behavioral mechanism by showing that, in a butterfly with extensive ecotypic variation, Edith's checkerspot, diet breadths increased after colonization events as diversification of individual host preferences pulled novel hosts into population diets. Subsequently, populations that persisted reverted toward monophagy. We draw together three lines of evidence from long-term studies of 15 independently evolving populations. First, direct observations showed a significant increase in specialization across decades: in recent censuses, eight populations used fewer host genera than in the 1980s while none used more. Second, behavioral preference-testing experiments showed that extinctions and recolonizations at two sites were followed, at first by diversification of heritable preference ranks and increases in diet breadth, and subsequently by homogenization of preferences and contractions of diet breadth. Third, we found a significant negative association in the 1980s between population-level diet breadth and genetic diversity. Populations with fewer mtDNA haplotypes had broader diets, extending to 3-4 host genera, while those with higher haplotype diversity were more specialized. We infer that diet breadth had increased in younger, recently colonized populations. Preference diversification after colonization events, whether caused by (cryptic) host shifts or by release of cryptic genetic variation after population bottlenecks, provides a mechanism for known effects of range shifts on diet specialization. Our results explain how colonizations at expanding range margins have increased population-level diet breadths, and predict that increasing specialization should accompany population persistence as current range edges become range interiors.

Mosquito Distribution in Northwestern Russia: Species of the Genera Anopheles Meigen, Coquillettidia Dyar, Culex L., and Culiseta Felt (Diptera, Culicidae)

Records of 16 species of the mosquito genera Anopheles, Coquillettidia, Culex, and Culiseta (Diptera: Culicidae) in Northwestern Russia are mapped. The values of the sum of active temperatures above 0°C were shown to correlate with the position of the northern range boundaries of mosquito species, according to which 16 species were included in 4 distribution groups.

Effectively and accurately mapping global biodiversity patterns for different regions and taxa

AbstractAimThe aim was to understand the representativeness and accuracy of expert range maps and to explore alternative methods for mapping species distributions accurately.LocationGlobal.Time periodContemporary.Major taxa studiedTerrestrial vertebrates and Odonata.MethodsWe analysed the biases in 50,768 animal International Union for Conservation of Nature, Global Assessment of Reptile Distributions and BirdLife species maps and assessed the links between these maps and existing political boundaries and various non‐ecological boundaries to assess their accuracy for certain types of analyses. We cross‐referenced each species map with data from the Global Biodiversity Information Facility to assess whether maps captured the whole range of a species and what percentage of occurrence points fell within the assessed range of the species. In addition, we used a number of different methods to map diversity patterns and compared these with high‐resolution models of distribution patterns.ResultsOn average, 20–30% of the non‐coastal range boundaries of species overlapped with administrative national boundaries. In total, 60% of areas with the highest spatial turnover in species (high densities of species range boundaries marking high levels of shift in the community of species present) occurred at political boundaries, which was especially common in Southeast Asia. Different biases existed for different taxa, with gridded analysis in reptiles, river basins in Odonata (except the Americas) and county boundaries for amphibians in the USA. On average, up to half (25–46%) of the recorded range points of species fell outside their mapped distributions. Filtered minimum convex polygons performed better than expert range maps in reproducing modelled diversity patterns.Main conclusionsExpert range maps showed high bias at administrative borders in all taxa, but this was highest at the transition from tropical to subtropical regions. The methods used were inconsistent across space, time and taxa, and the ranges mapped did not match species distribution data. Alternative approaches can reconstruct patterns of distribution better than expert maps, and data‐driven approaches are needed to provide reliable alternatives to gain a better understanding of species distributions.

Assessment of curly birch introduction prospects

We introduce an analysis of the experience of curly birch introductions accumulated in Russia and abroad, from which the main means and methods of evaluating introduction prospects were derived. It follows from this analysis that the most important and commonly used approaches and criteria are: comparison of the edaphic and climatic conditions in the prospective introduction site and the location from which the source material is taken (climate analogues method), assessment of the origin and biological characteristics of the source material, assessment of the composition of stand-forming tree species and their companion species in the prospective introduction site. In addition, we suggest the “distance method”, providing information about the distance from the species range boundary to the prospective introduction site, and about the distance over which curly birch has been moved for introduction before relative to the “averaged” distance. The importance of cultural operations, stocking rate and density of the planted trees for the expression of “figured grain” and “figure intensity” features in wood is highlighted. It is concluded that although curly birch has quite high ecological plasticity and, accordingly, a high introduction potential, the prospects for its introduction should be assessed using a widest possible set of indirect criteria and indicators, which will collectively yield a more probable future estimate of the introduction outcome, and generate a premise for improving its efficiency. The lack of the said integrated approach to evaluating the prospects of introduction is a key reason for its underperformance, notably reducing the chances of successfully dealing with the tasks of gene pool preservation and augmented reproduction of this unique member of the forest tree flora by means of introductions

AN EFFICIENT FOG ENABLED HEALTHCARE MAINTENANCE SYSTEM USING INTERNET OF THINGS WITH DEEP LEARNING STRATEGIES

Internet of Things (IoT) is the ruling term now-a-days, in which it attracts several smart gadgets and application due to its robust nature and support. In healthcare industry several new technologies are required to improve the stability and provide transparent services to clients. The integration of healthcare maintenance system with respect to Internet of Things support leads to a drastic change in healthcare field as well as this provision provides huge advantages to users. This paper is intended to provide an intense healthcare maintenance scheme by using latest technologies such as Deep Learning, Internet of Things, Fog Computing and Artificial Intelligence. All these innovations are associated together to build a new deep learning strategy called Intense Health Analyzing Scheme (IHAS), in which this proposed approach provides all provisions to clients such as Doctors and Patients with respect to monitor the patient details from anywhere at anytime without any range boundaries. The Fog Computing is an innovative domain, in which it provides ability to the server to operate based on hurdle free processing logic. Artificial Intelligence logic is used to manipulate the health data based on previously trained health records, so that the predictions are more fine compare to the classical healthcare schemes. In traditional schemes it is difficult to raise an alert based on the emergency situation predictions, but in the proposed deep learning strategy assists the proposed approach to send an alert instantly if any emergency cases occurred on patient end. Generally the Fog Servers are used to reduce the occupancy of the storage server and provide reliable storage abilities to server, but in this proposed approach, the fog server is utilized for priority wise data handling nature and stores the health records accordingly. In this nature, the fog servers are handled and provide high efficient results to the clients in an innovative way. With the help of deep learning procedures, the health records are clearly prioritized and maintained into the server end for monitoring. For all this paper introduced a new logic of healthcare maintenance scheme IHAS to provide efficient support to patients as well as doctors in clear manner.

Life-history theory provides a framework for detecting resource limitation: a test of the Nutritional Buffer Hypothesis.

For ungulates and other long-lived species, life-history theory predicts that nutritional reserves are allocated to reproduction in a state-dependent manner because survival is highly conserved. Further, as per capita food abundance and nutritional reserves decline (i.e., density dependence intensifies), reproduction and recruitment become increasingly sensitive to weather. Thus, the degree to which weather influences vital rates should be associated with proximity to nutritional carrying capacity-a notion that we refer to as the Nutritional Buffer Hypothesis. We tested the Nutritional Buffer Hypothesis using six moose (Alces alces) populations that varied in calf recruitment (33-69 calves/100 cows). We predicted that populations with high calf recruitment were nutritionally buffered against the effects of unfavorable weather, and thus were below nutritional carrying capacity. We applied a suite of tools to quantify habitat and nutritional condition of each population and found that increased browse condition, forage quality, and body fat were associated with increased pregnancy and calf recruitment, thereby providing multiple lines of evidence that declines in calf recruitment were underpinned by resource limitation. From 2001 to 2015, recruitment was more sensitive to interannual variation in weather (e.g., winter severity, drought) and plant phenology (e.g., duration of spring) for populations with reduced browse condition, forage quality, and body fat, suggesting these populations lacked the nutritional reserves necessary to buffer demographic performance against the effects of unfavorable weather. Further, average within-population calf recruitment was determined by regional climatic variation, suggesting that the pattern of reduced recruitment near the southern range boundary of moose stems from an interaction between climate and resource limitation. When coupled with information on habitat, nutrition, weather, and climate, life-history theory provides a framework to estimate nutritional limitation, proximity to nutritional carrying capacity, and impacts of climate change for ungulates.

Palaeontology meets metacommunity ecology: the Maastrichtian dinosaur fossil record of North America as a case study

AbstractDocumenting the patterns and potential associated processes of ancient biotas has always been a central challenge in palaeontology. Over recent decades, intense debate has focused on the organization of dinosaur‐dominated communities, yet no general consensus has been reached on how these communities were organized in a spatial context. Here, we used analytical routines typically applied in metacommunity ecology to provide novel insights into dinosaurian distributions across the latest Cretaceous of North America. To do this, we combined fossil occurrences with functional, phylogenetic and palaeoenvironmental modelling, and adopted the perspective that more reasonable conclusions on palaeoecological reconstructions can be gained from studies that consider the organization of biotas along ecological gradients at multiple spatial scales. Our results showed that dinosaurs were restricted in range to different parts of the Hell Creek Formation, prompting the recognition of discrete and compartmentalized faunal areas during the Maastrichtian at fine‐grained scales, whereas taxa with the broadest ranges included those with narrower distributions when combining data from various geological formations across the Western Interior of North America. Although groups of dinosaurs had coincident range boundaries, their communities responded to multiple ecologically‐important gradients when compensating for differences in sampling effort. Metacommunity structures of both ornithischians and theropods were correlated with climatic barriers and potential trophic relationships between herbivores and carnivores, thereby suggesting that dinosaurian faunas were shaped by physiological constraints, limited food resources abundance, and a combination of bottom‐up and top‐down forces across multiple spatial grains and extents.

Climate Change and Local Host Availability Drive the Northern Range Boundary in the Rapid Expansion of a Specialist Insect Herbivore, Papilio cresphontes

Species distributions, abundance, and interactions have always been influenced by human activity and are currently experiencing rapid change. Biodiversity benchmark surveys traditionally require intense human labor inputs to find, identify, and record organisms limiting the rate and impact of scientific enquiry and discovery. Recent emergence and advancement of monitoring technologies have improved biodiversity data collection to a scale and scope previously unimaginable. Community science web platforms, smartphone applications, and technology assisted identification have expedited the speed and enhanced the volume of observational data all while providing open access to these data worldwide. How to integrate and leverage the data into valuable information on how species are changing in space and time requires new best practices in computational and analytical approaches. Here we integrate data from three community science repositories to explore how a specialist herbivore distribution changes in relation to host plant distributions and other environmental factors. We generate a series of temporally explicit species distribution models to generate range predictions for a specialist insect herbivore (Papilio cresphontes) and three predominant host-plant species. We find that this insect species has experienced rapid northern range expansion, likely due to a combination of the range of its larval host plants and climate changes in winter. This case study shows rapid data collection through large scale community science endeavors can be leveraged through thoughtful data integration and transparent analytic pipelines to inform how environmental change impacts where species are and their interactions for a more cost effective method of biodiversity benchmarking.

The influence of spatial features and atmospheric conditions on African lion vocal behaviour

Long-distance vocalization is a characteristic of African lion, Panthera leo, behaviour and is important for maintaining territorial boundaries as well as locating distant group members. Vocal signalling is, however, a flexible behaviour that involves varying costs and benefits depending on environmental, social and spatial factors. Motivated by previous data collection limitations, we developed a novel approach to investigate the influence of atmospheric conditions and animal home range geography on lion vocal behaviour using acoustic and accelerometer biologgers. To compensate for the short lifetime of the acoustic biologger, we trained a machine-learning model to detect lion roars from long-term acceleration signals which yielded over 500 nights of data from seven individual lions. Analysis of detected roar events revealed that vocalizations occurred mainly at night with a peak just before dawn. The relative likelihood of vocalization was negatively related to wind speed and temperature and positively related to absolute humidity suggesting that lions preferred to roar under conditions that reduce sound attenuation and thereby maximize calling area. Roar occurrence was found to be dependent on an animal's location relative to its home range with lions demonstrating an apparent avoidance for vocalizing beyond the home range boundary. Lions were also more likely to roar repeatedly while closer to rivers and water points within their home range. This study is the first of its kind and not only improves the understanding of lion vocal behaviour but can also inform new approaches for recording animal vocalizations remotely.

Sharp boundary formation and invasion between spatially adjacent periodical cicada broods

Periodical cicadas, Magicicada spp., are a useful model system for understanding the population processes that influence range boundaries. Unlike most insects, these species typically exist at very high densities (occasionally >1000/ m2) and have unusually long life-spans (13 or 17 years). They spend most of their lives underground feeding on plant roots. After the underground period, adults emerge from the ground to mate and oviposit over a period of just a few days. Collections of populations that are developmentally synchronized across large areas are known as “broods”. There are usually sharp boundaries between spatially adjacent broods and regions of brood overlap are generally small. The exact mechanism behind this developmental synchronization and the sharp boundary between broods remain unknown: previous studies have focused on the impacts of predator-driven Allee-effects, competition among nymphs, and their impacts on the persistence of off-synchronized emergence events. Here, we present a nonlinear Leslie-type matrix model to additionally consider cicada movement between spatially separated broods, and examine its role in maintaining brood boundaries and within-brood developmental synchrony that is seen in nature. We successfully identify ranges of competition and dispersal that lead to stable coexistence of broods that differ between spatial patches.

Spawning phenology of a rapidly shifting marine fish species throughout its range

Abstract Ocean warming is leading to poleward range shifts for many fish species, and while well described, potential life history phenology differences within fish populations along a gradient from their historic to current distributional range have not been studied. In a rapidly shifting fish population, the Northern stock of black sea bass (Centropristis striata), we investigated spawning phenology and output across the US Northeast Shelf to comprise locations in their historic and more recently occupied range near their northern range boundary. Spawning started later in the northern extreme of our study but also ended earlier, leading to decreased spawning duration from south to north. Spawning phenology was mostly driven by Julian day followed by temperature and latitude. Gonadosomatic index, a proxy for reproductive output, was lower in the northern region, indicating that black sea bass did not compensate for the shorter spawning season there. Hepatosomatic index was lower in the northern regions indicating lower pre-spawning liver energy reserves, potentially leading to lower reproductive output. These results suggest a potential for lower recruitment in the recently occupied range and should be further investigated to predict the impacts of ocean warming and for proactive fisheries management as black sea bass distributional range expands poleward.

Plant–soil interactions limit lifetime fitness outside a native plant’s geographic range margin

Plant species' distributions are often thought to overwhelmingly reflect their climatic niches. However, climate represents only a fraction of the n-dimensional environment to which plant populations adapt, and studies are increasingly uncovering strong effects of nonclimatic factors on species' distributions. We used a manipulative, factorial field experiment to quantify the effects of soil environment and precipitation (the putatively overriding climatic factor) on plant lifetime fitness outside the geographic range boundary of a native California annual plant. We grew plants outside the range edge in large mesocosms filled with soil from either within or outside the range, and plants were subjected to either a low (ambient) or high (supplemental) spring precipitation treatment. Soil environment had large effects on plant lifetime fitness that were similar in magnitude to the effects of precipitation. Moreover, mean fitness of plants grown with within-range soil in the low precipitation treatment approximated that of plants grown with beyond-range soil in the high precipitation treatment. The positive effects of within-range soil persisted in the second, wetter year of the experiment, though the magnitude of the soil effect was smaller than in the first, drier year. These results are the first we know of to quantify the effects of edaphic variation on plant lifetime fitness outside a geographic range limit and highlight the need to include factors other than climate in models of species' distributions.

Lithologic features of near-surface layers of the Quaternary cover as a key to understanding of environmental constraints for the Quaternary ground squirrel species

ABSTRACT Here, we propose the modern soil map as a source for creating spatial context for agent-based modelling of the historical expansion and dispersal of ground squirrel species. On the basis of this soil map, we produced a lithologic map of the near-surface layers of the Quaternary cover. Units of this new lithologic map (i.e. certain kinds of substrate) were assessed in context of preferability by certain ground squirrel species. Then, these (basic) preference rates were modified for the case of valley slopes (positive impact of valley slopes) and for the case of loess-and-soil accumulation (also positive impact). The hypothesis of the positive impact of loess and soil accumulation is supported by following facts: range shrinking of Spermophilus species in the Holocene; stability of the range boundary between Spermophilus pygmaeus and Spermophilus suslicus in the Middle and Late Pleistocene and the ability of the Pleistocene ecosystems to support high animal biomass even during cold epochs.

Absentee owners and overlapping home ranges in a territorial species

Understanding animals’ use of space can shed valuable light on multiple other aspects of behavioral ecology, including social organization, dispersal, and foraging efficiency. Home ranges, territories, core areas, and home range overlaps have been widely studied, but unless animals are directly observed or are tracked remotely on a fine temporal scale, how they actually use the space available to them and how they share (or partition) this space with a community of conspecifics over time cannot be fully understood. Using GPS technology, we tracked three adjacent groups of vervet monkeys (Chlorocebus pygerythrus) in Laikipia, Kenya, for 1 year to better understand the processes involved in territoriality and home range overlaps. Home ranges overlapped with any one neighboring group by 12.7–34.7%, but intergroup encounters only occurred in restricted areas within these zones, which defined territorial boundaries. The resources closest to the territorial boundaries were nocturnal core areas with preferred sleeping sites adjacent to short-grass areas offering fewer hiding places for ambush predators and greater visibility for predator detection. Home range overlaps were not neutral zones, the result of shifting home range boundaries over time, or based on intergroup encounters at boundaries, but resulted when groups made incursions beyond their territorial boundaries while the neighbor was far away and likely unaware of the intruders. Thus, territories can be non-exclusive but may still be perceived by the animals themselves as sole-owned, as neighbors only intrude when territory owners are absent from that area. How animals use their space is a perennial focus in behavioral ecology because space use influences nearly everything else in animals’ lives. While tracking has long been used to investigate space use, particularly for nocturnal animals, only direct observation or tracking on a fine scale can reveal the processes involved in the creation or maintenance of home ranges and territories and that cause home range overlaps to persist. We remotely tracked three adjacent groups of vervet monkeys on a fine temporal scale for 1 year. Despite behaving territorially, vervet home ranges overlapped well beyond territorial boundaries because neighbors were “absentee owners,” unable to prevent incursions when they were not nearby. Our findings suggest that exclusivity of use in the definition of territoriality may be too strict; animals may behave as if they are exclusive owners even if neighbors’ use of space does not reflect it.

Poboljšanje mera bezbednosti primenom tehničkog rešenja na borbenom vozilu pešadije M-80A

Introduction/purpose: The paper presents a solution for overcoming a possible problem - breach of safety measures when operating the BVP M80A Infantry Combat Vehicle on a training ground during tactical exercises and shooting at night. The crux of the problem is that the officer in charge of a tactical exercise and shooting is not in a position to observe in which direction the gunner-operator aims because no device has been installed on the BVP M-80A to signal this. Methods: After deploying the vehicle in practice and and on the basis of experience during shooting, it was concluded that there is a problem of controlling shooting at night and in reduced visibility conditions. Results: The paper provides a practical solution to prevent situations such as disorientation, impossibility of observing targets, and turning weapons towards the outside the shooting range boundaries, thus violating the security measures of all participants in the exercise including the BVP M80A unit itself. A technical improvement was implemented on the vehicle by installing a signaling device that gives visual information to the officer in charge of shooting in which direction the weapon is turned. Conclusion: The installed signaling device enables the officer who commands the exercise and shooting to be in control in a timely manner, eliminate possible causes of violation of security measures, and successfully implement the planned activity.

Microbes, mutualism, and range margins: testing the fitness consequences of soil microbial communities across and beyond a native plant's range.

Interactions between plants and soil fungi and bacteria are ubiquitous and have large effects on individual plant fitness. However, the degree to which spatial variation in soil microbial communities modulates plant species' distributions remains largely untested. Using the California native plant Clarkia xantiana ssp. xantiana we paired glasshouse and field reciprocal transplants of plant populations and soils to test whether plant-microbe interactions affect the plant's geographic range limit and whether there is local adaptation between plants and soil microbe communities. In the field and glasshouse, one of the two range interior inocula had a positive effect on plant fitness. In the field, this benefit was especially pronounced at the range edge and beyond, suggesting possible mutualist limitation. In the glasshouse, soil inocula from beyond-range tended to increase plant growth, suggesting microbial enemy release beyond the range margin. Amplicon sequencing revealed stark variation in microbial communities across the range boundary. Plants dispersing beyond their range limit are likely to encounter novel microbial communities. In C.x.xantiana, our results suggest that range expansion may be facilitated by fewer pathogens, but could also be hindered by a lack of mutualists. Both negative and positive plant-microbe interactions will likely affect contemporary range shifts.