Habitat Structure Research Articles

Razor clam (Pinna bicolor) structural mimics as drivers of epibenthic biodiversity; a manipulative experiment

Shellfish ecosystems facilitate important ecological functions and communities, but overexploitation and mismanagement have contributed to their decline worldwide. Within recent decades, coastal management efforts have increasingly sought to understand and reinstate valuable ecological functions provided by habitat-forming bivalves including oysters, mussels and pinnids. However, many bivalve species are critically understudied, limiting restoration and ecological engineering opportunities. Pinnids, specifically, are an underappreciated bivalve group, with razor clams (Pinna bicolor) forming dense aggregations, and potentially supporting important ecological functions. This study, conducted in an urban Australian estuary, was a manipulative experiment that investigated whether artificial razor clam shells could facilitate beneficial ecological functions through the provision of structural habitat. Specifically, we investigated the influence of intertidal benthic structures, including the micro-habitat influences of surface structure associated with mortality status (open or closed shell), and the short-term response of the benthic and epifaunal communities. Within 12 weeks, the structural razor clam mimics rapidly changed the aboveground ecological community, relative to the bare habitat controls. Both open and closed artificial shells provided a settlement surface for epiphytic organisms and supported enhanced epifaunal biodiversity. Contrastingly, the artificial structures did not significantly alter sediment characteristics or infaunal macroinvertebrate composition in the surrounding benthos. These results provide important insights into the rapid ecological response to the installation of intertidal pinnid structures in dynamic estuarine ecosystems. Furthermore, we provide a case study for understanding the ecological functions of an understudied habitat-forming species, which could be used to inform future restoration and management efforts.

Seabird inputs drive changes in Cladocera assemblages in freshwater ponds

Seabirds are biovectors that transport large concentrations of nutrients from their marine feeding areas to terrestrial breeding grounds. Here, we used subfossil cladoceran assemblages to assess if, and how, changes in the world’s largest colony of Leach’s Storm Petrels affected the structure of Cladocera assemblages over the past ~1700 years. Using sediment cores from four ponds impacted by Leach’s Storm-Petrel colonies on Baccalieu Island (NL, Canada), we observed a consistent transition in cladoceran assemblages from benthic/littoral to pelagic taxa in association with high seabird presence. This shift aligns with previously published limnological changes that tracked the growth of the colony. Compared to trends in sedimentary chlorophyll-a, pelagic cladoceran taxa lagged behind algal shifts driven by seabird activity. The main drivers of cladoceran assemblage shifts were likely alterations to the physical habitat structure and food availability driven by seabird inputs. Furthermore, deposition of calcium from seabirds may have also contributed to changing the composition of cladoceran communities. Our study provides information on food web shifts associated with seabird-driven eutrophication, which can be compared to future paleoecological studies.

Assessment of imaging risks for recurrence after stereotactic radiosurgery for brain metastases (IRRaS-BM)

BackgroundThe identification of viable tumors and radiation necrosis after stereotactic radiosurgery (SRS) is crucial for patient management. Tumor habitat analysis involving the grouping of similar voxels can identify subregions that share common biology and enable the depiction of areas of tumor recurrence and treatment-induced change. This study aims to validate an imaging biomarker for tumor recurrence after SRS for brain metastasis by conducting tumor habitat analysis using multi-parametric MRI.MethodsIn this prospective study (NCT05868928), patients with brain metastases will undergo multi-parametric MRI before SRS, and then follow-up MRIs will be conducted every 3 months until 24 months after SRS. The multi-parametric MRI protocol will include T2-weighted and contrast-enhanced T1-weighted imaging, diffusion-weighted imaging, and dynamic susceptibility contrast imaging. Using k-means voxel-wise clustering, this study will define three structural MRI habitats (enhancing, solid low-enhancing, and nonviable) on T1- and T2-weighted images and three physiologic MRI habitats (hypervascular cellular, hypovascular cellular, and nonviable) on apparent diffusion coefficient maps and cerebral blood volume maps. Using RANO-BM criteria as the reference standard, via Cox proportional hazards analysis, the study will prospectively evaluate associations between parameters of the tumor habitats and the time to recurrence. The DICE similarity coefficients between the recurrence site and tumor habitats will be calculated.DiscussionThe tumor habitat analysis will provide an objective and reliable measure for assessing tumor recurrence from brain metastasis following SRS. By identifying subregions for local recurrence, our study could guide the next therapeutic targets for patients after SRS.Trial registrationThis study is registered at ClinicalTrials.gov (NCT05868928).

Taxonomic and Functional Diversity of Reptiles in a Heterogeneous Landscape of Jalisco State, West-Central Mexico

Reptiles are threatened by anthropogenic landscape transformation, largely due to agriculture. However, ecosystems nowadays constitute a matrix of fragmented landscapes. We analyzed a heterogeneous landscape’s reptile taxonomic and functional diversity patterns across ten land cover/use types in Jalisco state, in west-central Mexico. At the alpha diversity level, we assessed the taxonomic diversity using q-order indices, and functional diversity with multidimensional indices (FRic, FDiv, and FEve) by land cover/use. We evaluated the differences in species composition among land cover/use types (beta diversity). We utilized multidimensional distance-based analyses (dbRDA) to evaluate the association between reptile diversity, habitat structure, and environmental variables. Species richness did not correlate with functional richness across land cover types overall, except for riparian habitat surrounded by crops (RH-C), which exhibited higher species richness and functional diversity. Secondary vegetation surrounded by temperate forest (SV-TF), riparian habitat surrounded by tropical dry forest (RH-TDF), and RH-C were the land cover/use types with the most functional groups. Herbaceous cover is crucial for preserving both reptile diversity facets in this landscape. These findings suggest that the availability of resources (e.g., riparian habitat and herbaceous cover) regardless of perturbation level could be more relevant for reptile diversity than the condition (tropical vs. temperate) due to the high plasticity and adaptation of the group. It is essential to recognize the ecological value of these habitats by adopting a holistic approach that values the intrinsic and ecological importance of reptile diversity.

Dynamic shifts of functional diversity through climate-resilient strategies and farmland restoration in a mountain protected area

Land-use land-cover (LULC) change contributes to major ecological impacts, particularly in areas undergoing land abandonment, inducing modifications on habitat structure and species distributions. Alternative land-use policies are potential solutions to alleviate the negative impacts of contemporary tendencies of LULC change on biodiversity.This work analyzes these tendencies in the Montesinho Natural Park (Portugal), an area representative of European abandoned mountain rural areas. We built ecological niche models for 226 species of vertebrates (amphibians, reptiles, birds, and mammals) and vascular plants, using a consensus modelling approach available in the R package ‘biomod2’. We projected the models to contemporary (2018) and future (2050) LULC scenarios, under four scenarios aiming to secure relevant ecosystem services and biodiversity conservation for 2050: an afforestation and a rewilding scenario, focused on climate-smart management strategies, and a farmland and an agroforestry recovery scenario, based on re-establishing human traditional activities. We quantified the influences of these scenarios on biodiversity through species habitat suitability changes for 2018–2050. We analyzed how these management strategies could influence indices of functional diversity (functional richness, functional evenness and functional dispersion) within the park.Habitat suitability changes revealed complementary patterns among scenarios. Afforestation and rewilding scenarios benefited more species adapted to habitats with low human influence, such as forests and open woodlands. The highest functional richness and dispersion was predicted for rewilding scenarios, which could improve landscape restoration and provide opportunities for the expansion and recolonization of forest areas by native species. The recovery of traditional farming and agroforestry activities results in the lowest values of functional richness, but these strategies contribute to complex landscape matrices with diversified habitats and resources. Moreover, this strategy could offer opportunities for fire suppression and increase landscape fire resistance. An integrative approach reconciling rewilding initiatives with the recovery of extensive agricultural and agroforestry activities is potentially an harmonious strategy for supporting the provision of ecosystem services while securing biodiversity conservation and functional diversity within the natural park.

Habitat complexity versus habitat heterogeneity: Invertebrates prefer macrophyte stands with intermediate biomass and high functional diversity

Abstract Aquatic macrophytes serve as shelter and a direct source of food for invertebrates, in addition to indirectly providing items such as algae, detritus, and microorganisms. Thus, aquatic macrophytes act as habitat structuring elements, requiring a distinction between habitat complexity (physical formations such as fractal dimensions, density and biomass) and habitat heterogeneity (diversity of these structures). Here we explore the effects of habitat complexity and habitat heterogeneity on the invertebrate community. We collected macrophytes and invertebrates from 28 sampling sites along a 13.7‐km stretch of the Baía River in Brazil, and examined specific groups (insects, microcrustaceans, and other invertebrates). Environmental variables in the sites were also measured. We aimed to explore the effects of habitat complexity (measured by macrophyte biomass) and habitat heterogeneity (evaluated through macrophyte functional diversity) on the richness and abundance of invertebrates. We found that overall invertebrate richness was positively influenced solely by habitat heterogeneity. For invertebrate abundance, intermediate habitat complexity had more invertebrates, while habitat heterogeneity had a positive impact. Environmental variables influenced only the abundance. For specific groups, insect richness was positively influenced by habitat heterogeneity, while insect abundance decreased with high complexity and increased with high heterogeneity. Microcrustacean abundance was positively influenced by habitat complexity. Richness and abundance of other invertebrates was positively influenced by habitat heterogeneity. Invertebrates prefer macrophyte stands with intermediate complexity and high heterogeneity. Abundance is linked to structural complexity and heterogeneity, while species richness is more strongly associated with heterogeneity. Furthermore, the impact of these factors varies among invertebrate groups. These findings emphasise the importance of integrating a broad range of metrics, such as macrophyte biomass and functional diversity, to gain a thorough understanding of invertebrate community dynamics in future studies. Additionally, our study demonstrates that preserving macrophyte stands with high heterogeneity significantly enhances the diversity of associated invertebrate species.

Ecologically sustainable retention forestry supports spider biodiversity in the Lower Morava UNESCO Biosphere Reserve

Abstract Floodplain forests are among the most endangered ecosystems worldwide, even though they are hotspots for numerous taxa. The abandonment of traditional management and large‐scale timber extraction, such as clear‐cutting, has led to a decline in floodplain forest biodiversity. Retention forestry has the potential to facilitate the implementation of an ecologically sustainable forest management approach. Despite the increasing popularity of this method, its potential for spider diversity conservation, especially its comparison with the widespread practice of clear‐cutting, is still poorly studied. We studied the short‐term effect of forestry treatments (dispersed retention with 60% retained trees and clear‐cutting) on the diversity of ground‐dwelling spiders in the floodplain forests along the Lower Morava (March) and Dyje (Thaya) rivers in the Czech Republic. Spiders were sampled using pitfall traps during 2021 (pre‐harvest year) and 2022 (post‐harvest year). A total of 10,005 specimens from 167 species were recorded. Both forestry treatments simplified habitat structure compared with pre‐harvest conditions, resulting in lower beta‐diversity within sites. However, dispersed retention had higher alpha‐ and beta‐diversity than clear‐cuts, indicating that retention provided a more complex‐structured habitat. Dispersed retention and clear‐cuts hosted distinct spider assemblages with characteristic indicator species. Species typical of open and significantly disturbed habitats preferred clear‐cuts, while species typical of forests and (semi‐) open habitats, including threatened species, showed a preference for dispersed retention. Our results demonstrated, for the first time, that dispersed retention forestry could serve as an effective management tool for conserving the ground‐dwelling assemblages of spiders in floodplain forests.

Unique functional diversity during early Cenozoic mammal radiation of North America.

Mammals influence nearly all aspects of energy flow and habitat structure in modern terrestrial ecosystems. However, anthropogenic effects have probably altered mammalian community structure, raising the question of how past perturbations have done so. We used functional diversity (FD) to describe how the structure of North American mammal palaeocommunities changed over the past 66 Ma, an interval spanning the radiation following the K/Pg and several subsequent environmental disruptions including the Palaeocene-Eocene Thermal Maximum (PETM), the expansion of grassland, and the onset of Pleistocene glaciation. For 264 fossil communities, we examined three aspects of ecological function: functional evenness, functional richness and functional divergence. We found that shifts in FD were associated with major ecological and environmental transitions. All three measures of FD increased immediately following the extinction of the non-avian dinosaurs, suggesting that high degrees of ecological disturbance can lead to synchronous responses both locally and continentally. Otherwise, the components of FD were decoupled and responded differently to environmental changes over the last ~56 Myr.

Habitat structural complexity predicts cognitive performance and behaviour inwestern mosquitofish.

Urban stream syndrome alters stream habitat complexity. We define habitat complexity as the degree of variation in physical habitat structure, with increasing variation equating to higher complexity. Habitat complexity affects species composition and shapes animal ecology, physiology, behaviour and cognition. We used a delayed detour test to measure whether cognitive processes (motor self-regulation) and behaviour (risk-taking) of female Western mosquitofish, Gambusia affinis, varied with habitat structural complexity (low, moderate and high) that was quantified visually for nine populations. We predicted that motor self-regulation and risk-taking behaviour would increase with increasing habitat complexity, yet we found support for the opposite. Lower complexity habitats offer less refuge potentially leading to higher predation pressure and selecting for greater risk-taking by fish with higher motor self-regulation. Our findings provide insight into how habitat complexity can shape cognitive processes and behaviour and offers a broader understanding of why some species may tolerate conditions of urbanized environments.

Habitat and Population Structure of Lobster from Southern of West Java

Losbter is a an important and highly economical resources on Coastal Area, in Indian Ocean, including southern part of Java. The research on there area in Pamengpeuk (Garut), South Cianjur, Ujung Genteng conducting to evaluate of habitat and distribution, water quality and population structure. The research result shown the lobster larvae dominant on coastal and near beach, and adult lobster on deeper zone than larvae, and water quality relatively good. The species dominant found are Panulirus homarus and Panulirus pennicilatus) with composition 48%:52%. The size structure in Ujung Genteng relatively growth rapidly than Cianjur and Pamengpeuk. The finding of lobster research in this area are environmental quality appropriate where P homarus and penniculatus as dominat species, with good growth rate.

Biodiversity and Vegetation Succession in Vineyards, Moravia (Czech Republic)

Maintaining biodiversity in agricultural landscapes is a major challenge for environmental protection in Europe. Vineyards rely heavily on agrotechnical interventions such as herbicide use and tillage for weed control, which affect biodiversity and can lead to soil erosion and resistant weed populations. The fragmentation of agricultural landscapes affects biodiversity by altering community composition and often reducing plant population sizes and genetic diversity. However, it can also increase the abundance of certain species and enhance population resilience to environmental change. Vineyards can support high levels of biodiversity and provide ecosystem services due to their semi-natural habitat structure. This research evaluates vegetation biodiversity using phytosociological relevés in different vineyards. Our results show that species richness and biodiversity are significantly influenced by vineyard age and management type. This study highlights differences in the representation of plant functional groups, with perennial taxa in grassy inter-row contributing to anti-erosion functions and serving as food sources for pollinators. The root zone around vine trunks shows an increase in invasive species with vineyard age, posing a risk to the agroecosystem. Vineyards predominantly follow a ruderal ecological strategy, using nutrients and light efficiently, while tolerating management disturbances. Understanding these dynamics is critical for developing sustainable vineyard management practices that support biodiversity and ecological resilience, counteract the homogenization of agricultural landscapes, and promote the coexistence of viticulture and species-rich ecosystems.

Out of shape: Ocean acidification simplifies coral reef architecture and reshuffles fish assemblages.

Climate change stressors are progressively simplifying biogenic habitats in the terrestrial and marine realms, and consequently altering the structure of associated species communities. Here, we used a volcanic CO2 seep in Papua New Guinea to test insitu if altered reef architecture due to ocean acidification reshuffles associated fish assemblages. We observed replacement of branching corals by massive corals at the seep, with simplified coral architectural complexity driving abundance declines between 60% and 86% for an assemblage of damselfishes associated with branching corals. An experimental test of habitat preference for a focal species indicated that acidification does not directly affect habitat selection behaviour, with changes in habitat structural complexity consequently appearing to be the stronger driver of assemblage reshuffling. Habitat health affected anti-predator behaviour, with P. moluccensis becoming less bold on dead branching corals relative to live branching corals, irrespective of ocean acidification. We conclude that coral reef fish assemblages are likely to be more sensitive to changes in habitat structure induced by increasing pCO2 than any direct effects on behaviour, indicating that changes in coral architecture and live cover may act as important mediators of reef fish community structures in a future ocean.

Modeling abundance and nest occupation of Pseudomyrmex termitarius as a function of detection factors and habitat structure in fragments of urban vegetation

Understanding the relationship between abundance and habitat variability is an underlying theme of ecological studies. Due to imperfect detection, robust estimates of population size require large efforts, especially for megadiverse taxa such as Formicidae, where most of the surveys rely on presence-absence or community data. Here, we used mixed occupation models to estimate the population abundance and local distribution of Pseudomyrmex termitarius (Formicidae: Pseudomyrmecinae) in nests when detection was imperfect. Our goal was to create a sampling protocol to estimate unbiased population parameters, taking into account several sources of heterogeneity that can affect the estimates (e.g., researcher detection variability, survey period, habitat variables). The advantage of this protocol is that it is time- and cost-effective for accessing common and easily identifiable ant species. We distributed 44 transects (2.5 × 20 m) with five subplots each in 2.33 ha of the vegetation remnants of the Cuiabá Campus of the Federal University of Mato Grosso (UFMT). In each subsample, we recorded the presence or absence of P. termitarius workers, as well as the count of other cooccurring ant species during two consecutive days and time periods (midday and 16:00). Canopy openness and soil compaction were recorded in each transect. Among all the sampling trials, we directly counted a maximum of 364 P. termitarius workers in 92 subplots. Both nest abundance and occupation estimates were directly related to soil compaction. The estimated probability of detection was 39% and was not affected by the period. On the other hand, despite P. termitarius being a noncryptic species in the study area, it had a stronger effect on detectability. Although P. termitarius is a subordinate species, the co-occurrence of other species does not explain its abundance and distribution in our study. Perhaps P. termitarius's preference for sites with more compact soils could favor it by filtering out or reducing the abundance of potential competitors. After taking into account soil compaction and researcher detection variability, we estimated that the species occurred in 70% of the study area with a density of approximately 0.09 nests/m². We expect that this protocol can be an additional tool to improve the knowledge of ants in general and, especially, the management of alien or economically relevant ant species.

Evaluation of Ecological Sensitivity and Spatial Correlation Analysis of Landscape Patterns in Sanjiangyuan National Park

The Sanjiangyuan region, situated on the Qinghai–Tibetan Plateau, constitutes an exceptionally delicate ecological environment. Alterations in the region’s ecological landscape stem not only from natural factors but also from significant anthropogenic influences, exerting a notable impact on the sustainable economic and social development of the region’s middle and lower reaches. Consequently, investigating changes in the landscape pattern of Sanjiangyuan National Park holds paramount importance for comprehending the formation mechanism of spatial landscape distribution in the area. This study analyzes the ecological sensitivity and landscape pattern of Sanjiangyuan National Park in Qinghai Province, China, utilizing ArcGIS 10.8 and Fragstats 4.2. Employing the bivariate spatial autocorrelation analysis method, the research uncovers the spatial distribution characteristics between ecological sensitivity and landscape pattern, along with their aggregated change traits. The findings reveal that ecological sensitivity areas within the park encompass varying degrees, ranging from extremely sensitive to insensitive. The area of moderately sensitive zones in the Yellow River source region is 7279.67 km2 (39.17%), whereas the corresponding area in the Yangtze River source region is 32,572.34 km2 (36.30%). The eastern and northern parts of the Sanjiangyuan National Park exhibit significant landscape fragmentation. Ecological sensitivity varies markedly across different regions, with the southern and some northern areas showing higher sensitivity. In the Lancang River source park and the southern part of the Yellow River source park, the Largest Patch Index (LPI) and Ecological Sensitivity Index exhibit a high–high (HH) clustering pattern, indicating strong ecological connectivity in these areas. These regions also feature high Total Edge (TE), Number of Patches (NP), Patch Density (PD), and Edge Density (ED), indicating a complex landscape structure and abundant habitat edge areas. The study recommends restoring ecological connectivity in highly fragmented areas and implementing strict protection measures in sensitive regions to maintain ecosystem health and biodiversity. These findings provide a foundation for developing targeted ecological protection measures to enhance ecosystem health and biodiversity conservation in the area. This research aligns with several Sustainable Development Goals (SDGs), including Climate Action, Life on Land, and Clean Water and Sanitation, by promoting sustainable ecosystem management and biodiversity conservation.

STOCHASTICITY, SCALE, AND REFRACTION: DETERMINANTS OF POPULATION SYNCHRONY IN PARASITES OF CENTRARCHIDS IN J. STROM THURMOND LAKE, SOUTH CAROLINA.

Among-deme asynchrony has the potential to influence community richness and diversity by increasing the likelihood of regional persistence for a species. Parasites of Lepomis spp. collected from 4 localities at J. Strom Thurmond Lake, South Carolina over a 1-yr period were used to evaluate patterns of parasite population synchrony. Localities were separated by approximately 5 km to increase the likelihood that the parasites sampled represented different demes. Tylodelphys scheuringi and Crinicleidus longus, exhibited negative covariation between synchrony and among-locality distances. The degree of synchrony exhibited by Neoechinorhynchus cylindratis, Crepidostomum cornutum, and Clavunculus bifurcatus was associated with the degree of similarity in habitat structure between localities. Patterns of synchrony for Posthodiplostomum minimum and Spinitectus sp. were not associated with any of the habitat variables examined. The influence of habitat structure on parasite population synchrony, possibly through the refraction of large-scale environmental drivers, has the potential to produce asynchronous dynamics that are independent of the distance between demes, thereby promoting regional persistence by increasing the likelihood of rescue effects.

Performance Analysis of Automated Parcel Lockers in Urban Delivery: Combined Agent-Based–Monte Carlo Simulation Approach

Background: The habitat structure, the environmental impact, the market acceptance, the changes in consumers’ preferences, and the pandemic urged for innovative solutions in urban last-mile delivery. Parcel lockers are among the most preferred solutions by customers due to their home proximity, time availability, and cost efficiency. Methods: This paper introduces an agent-based model (ABM) and a Monte Carlo simulation program to analyze in detail the activity of parcel locker points. The ABM describes the behavior of the agents (customers, parcels, lockers, delivery agents). The simulation is realized using ARENA 12 software. Two scenarios are created based on the number of daily delivery shifts; for each scenario, 300 simulation experiments with various input data are conducted. Results: Three measures of performance (MOPs) are selected to assess the system activity: the number of daily delivered parcels, the delivery time of an order, and the daily delayed orders. The simulation outputs reveal significant predictors of MOPs and disclose moments when actions need to be taken to increase system capacity or change customer behavior. Conclusions: The versatility of the simulation model in terms of input variables makes it a useful decision support tool for planning by highlighting quantitative assessments, organizing delivery activity, along with influences due to customer behavior changes.

Metabarcoding the Bacterial Assemblages Associated with Toxopneustes roseus in the Mexican Central Pacific.

The Mexican Central Pacific (MCP) region has discontinuous coral ecosystems with different protection and anthropogenic disturbance. Characterizing the bacterial assemblage associated with the sea urchin Toxopneustes roseus and its relationship with environmental variables will contribute to understanding the species' physiology and ecology. We collected sea urchins from coral ecosystems at six sites in the MCP during the summer and winter for two consecutive years. The spatial scale represented the most important variation in the T. roseus bacteriome, particularly because of Isla Isabel National Park (PNII). Likewise, spatial differences correlated with habitat structure variables, mainly the sponge and live coral cover. The PNII exhibited highly diverse bacterial assemblages compared to other sites, characterized by families associated with diseases and environmental stress (Saprospiraceae, Flammeovirgaceae, and Xanthobacteraceae). The remaining five sites presented a constant spatiotemporal pattern, where the predominance of the Campylobacteraceae and Helicobacteraceae families was key to T. roseus' holobiont. However, the dominance of certain bacterial families, such as Enterobacteriaceae, in the second analyzed year suggests that Punto B and Islas e islotes de Bahía Chamela Sanctuary were exposed to sewage contamination. Overall, our results improve the understanding of host-associated bacterial assemblages in specific time and space and their relationship with the environmental condition.

Drivers of autochthonous malaria cases over time: could the Central European present the African future?

BackgroundResults of spatial and temporal comparison of malaria hotspots and coldspots could improve the health measures of malaria control and eradication strategies. The study aimed to reveal the spatially and temporally independent correlations between the potentially most effective background variables and the number of autochthonous malaria cases.MethodsRelationships between malaria cases and background variables were studied in 2 km × 2 km sized quadrates (10 Central European and 10 African). In addition to the current habitat structure of the African sites, annual precipitation, and annual mean temperature, data of the above parameters detected in the nineteenth and twentieth centuries and currently in the Central European sites were included in the analyses (n = 40). Mann–Whitney tests, Principal Component Analysis, and Generalized Linear Models were used for the examinations.ResultsIn addition to the apparent significant positive correlation of malaria cases with annual rainfall and mean temperature, several correlations were found for habitat parameters. The cover of marshlands in the 19th-century habitat structure of Central European quadrates was considerably the same as in the recent African ones. The extent of rural residential areas was significantly smaller in the 19th-century habitat structure of Central European quadrats than in present-day African ones. According to the revealed correlations, the surface cover of rural residential areas is the main driver of the number of autochthonous malaria cases that we can directly impact.ConclusionsThe study confirmed with historical comparison that not only the annual rainfall and mean temperature, the cover of marshlands and other habitats with breeding sites, but also the elements of the rural human environment play a significant role in the high number of autochthonous malaria cases, probably through the concentration and enhancing sites for vector mosquitoes. The latter confirms that a rapid urbanization process could reduce malaria cases in the most infected areas of Africa. Until the latter happens, extensive biological control of Anopheles larvae and chemical control (both outdoor and indoor) of their imagoes, further mosquito nets, repellents, and carbon dioxide traps will need to be applied more widely in the most heavily infested areas.

Recovery potential of fish and coral populations following ecological disturbance

AbstractThe health of coral reef benthic and fish communities is implicitly connected, yet typically studied and managed separately. By developing a coupled reef population model that connects coral populations and reef fish biomass through the habitat complexity that corals build and fish live among, we aim to address this gap by holistically quantifying ecological feedbacks and responses to ecological stressors. We explored the impacts of fishing effort in conjunction with three types of ecological disturbances as they propagated through a coral reef ecosystem: (1) a disturbance that disproportionately affected small, bio‐energetically vulnerable colonies, (2) a disturbance that predominantly affected large, mechanically vulnerable colonies, and (3) a disturbance that affected colonies of all sizes randomly. We found that joint coral and fish population recovery was fastest and most complete under events affecting small colonies, followed by recovery from disturbances affecting random sizes, and lastly large‐colony disturbances. These results suggest that the retention versus loss of large coral colonies with high reproductive potential critically influenced population recovery. Low fishing levels maintained fish and coral populations and allowed for recovery after disturbances, whereas high fishing levels prevented recovery due to greater fish‐dependent coral mortality. Finally, we tested various formulations of the relationship between coral size and habitat complexity (i.e., exponential, linear, logarithmic) that constrain fish carrying capacity. All formulations led to similar population projections in most disturbance scenarios, but there were exceptions where the timing and trajectory of recovery differed, such as faster and greater recovery potential when complexity is logarithmic with respect to coral size. These findings suggest that fishing and habitat complexity mediate the recovery of coral reef populations, emphasizing the importance of describing linkages between coral size distribution and reef habitat structure. Furthermore, our results highlight the utility of the coupled‐model framework for understanding and managing the impact of disturbances at ecosystem scales.

Living together, feeding apart: the comparative foraging ecology of two African flycatcher species

This study examined how habitat and resource conditions influence the foraging behaviour and ecology of the Pale (Pallid) Flycatcher Agricola pallidus and Marico Flycatcher Bradornis mariquensis, two perch-and-pounce insectivores that swoop on prey from elevated perches. These species were studied in the early 1980s at the Nylsvley Nature Reserve in Limpopo Province, South Africa, where Marico Flycatchers occupied fine-leafed, spinescent Vachellia (Acacia) tortilis-dominated woodland, while Pale Flycatchers were confined to Burkea africana-dominated mesophyll woodland. These two woodland types correspond to two contrasting savanna types across Africa more broadly: arid-eutrophic, fine-leafed savannas and mesic/moist-dystrophic, broad-leafed woodlands. Their juxtaposition at the Nylsvley Reserve provided an opportunity to explore the factors affecting the habitat preferences and foraging behaviour of these two species. Acacia woodlands had higher invertebrate abundance, at least on the ground, and lower groundcover than Burkea woodlands in both seasons, although the difference was less during the dry season. Throughout the year, Marico Flycatchers consistently foraged at a faster rate, pouncing more frequently and more successfully on prey than did Pale Flycatchers. They also spent less time searching from each perch and gave up sooner if they found nothing. The average time difference between successful and unsuccessful searches was only a few seconds for both species, however. Presumably because they occupied a less productive woodland, Pale Flycatchers had considerably larger home ranges and occurred at lower densities overall, and so experienced fewer intraspecific and interspecific interactions. In contrast, Marico Flycatchers faced more competition both intra- and interspecifically, especially in the dry season when prey was scarce; they lost most of their conflicts, all with larger birds. Habitat separation between these two flycatcher species is apparently maintained by the differences in habitat structure, resource availability and occasional interspecific interactions, in which Marico Flycatchers dominated Pale Flycatchers.