Habitat Types Research Articles

Habitat context and functional growth traits explain alien plant invader impacts on native vegetation communities

AbstractExamining context-dependency of ecological impacts of alien plant invasions is critical to further understand the mechanisms driving impacts. We examined how different regional and local habitat contexts influence the abundance-impact associations of an invasive ground-creeper, Tradescantia fluminensis, in native forests across eastern New South Wales (NSW), Australia. Invader impacts were assessed using surveys of resident vegetation at 97 monitoring plots (5 m × 2 m) located at 14 sites, representing a gradient of T. fluminensis abundance. We modelled the association of T. fluminensis invasion with native species richness (number per plot) and foliage cover across two different habitat types (remnant vs replanted forests), two vegetation community types (wet sclerophyll vs river oak forests), and two regions (northern vs. southern NSW). We also modelled variation in native species responses amongst different functional growth forms. The negative associations of T. fluminensis and native species communities was more strongly explained by local site variables (i.e., habitat type, community type, plant growth form) than regional scales. Native richness reduced with invasion in river oak but not wet sclerophyll forest. Native richness also declined in remnant forest, although no effect of invasion was observed in replanted forest. Surprisingly, native species growth forms most like T. fluminensis (ground layer herbs, ferns) were more resistant to reductions in native richness compared to divergent forms (shrub, tree and woody vine recruits). This study highlights the need to explicitly consider local community and habitat context and functional representation of resident species when considering invader impacts and site-level management plans.

Global plant responses to intensified fire regimes

AbstractAimGlobal change factors, such as warming, heatwaves, droughts and land‐use changes, are intensifying fire regimes (defined here as increasing frequency or severity of fires) in many ecosystems worldwide. A large body of local‐scale research has shown that such intensified fire regimes can greatly impact on ecosystem structure and function through altering plant communities. Here, we aim to find general patterns of plant responses to intensified fire regimes across climates, habitats and fire regimes at the global scale.LocationWorldwide.Time periodStudies published 1962–2023.Major taxa studiedWoody plants, herbs and bryophytes.MethodsWe carried out a global systematic review and meta‐analysis of the response of plant abundance, diversity and fitness to increased fire frequency or severity. To assess the context dependency of those responses, we tested the effect of the following variables: fire regime component (fire frequency or severity), time since the last fire, fire type (wildfire or prescribed fire), historical fire regime type (surface or crown fire), plant life form (woody plant, herb or bryophyte), habitat type and climate.ResultsIntensified fire regimes reduced overall plant abundance (Hedges' d = −0.24), diversity (d = −0.27), and fitness (d = −0.69). Generally, adverse effects of intensified fire regimes on plants were stronger due to increased severity than frequency, in wildfires compared to prescribed fires, and at shorter times since fire. Adverse effects were also stronger for woody plants than for herbs, and in conifer and mixed forests than in open ecosystems (e.g. grasslands and shrublands).Main conclusionsIntensified fire regimes can substantially alter plant communities in many ecosystems worldwide. Plant responses are influenced by the specific fire regime component that is changing and by the biotic and abiotic conditions.

Catch yield and selectivity of a modified scallop dredge to reduce seabed impact.

Global scallop fisheries are economically important but are associated with environmental impacts to seabed communities resulting from the direct physical contact of the fishing gear with the seabed. Gear modifications attempting to reduce this contact must be economically feasible such that the catch numbers for the target species is maintained or increased. This study investigated the outcome of reducing seabed contact on retained catch of scallops and bycatch by the addition of skids to the bottom of the collecting bag of scallop dredges. We used a paired control experimental design to investigate the impact of the gear modification in different habitat types. The modified skid dredge generally caught more marketable scallops per unit area fished compared with the standard dredge (+5%). However, the skid dredge also retained more bycatch (+11%) and more undersize scallops (+16%). The performance of the two dredges was habitat specific which indicates the importance of adjusting management measures in relation to habitat type. To realize the potential environmental benefits associated with the improvement in catchability of this gear modification, further gear modification is required to reduce the catch of undersize scallops and bycatch. Furthermore we advocate that technical gear innovations in scallop dredging need to be part of a comprehensive and effective fisheries management system.

Apex predators can structure ecosystems through trophic cascades: Linking the frugivorous behaviour and seed dispersal patterns of mesocarnivores

Abstract Current global change scenarios demand knowledge on how anthropogenic impacts affect ecosystem functioning through changes in food web structure. Frugivorous mesocarnivores are a key link in trophic cascades because, while their abundance and behaviour are usually controlled by apex predators, they can provide high‐quality seed‐dispersal services to plant communities. Thus, the recent rewilding of large carnivores worldwide can trigger cascading effects for plants. We investigated the top‐down effects of an apex predator (Iberian lynx Lynx pardinus) on seed‐dispersal services mediated by two mesocarnivore species (red fox Vulpes vulpes and stone marten Martes foina) at the plant community level by comparing areas with and without lynx in a Mediterranean mountain range in Southern Spain. We collected scats of mesocarnivores (n = 1575) to assess frugivory and seed dispersal of 15 plant species over two consecutive fruiting seasons and two habitat types (open and forest). Specifically, we assessed the effect of lynx presence on (i) seed occurrence and fleshy‐fruit biomass per scat, (ii) number of scats containing seeds and (iii) diversity of dispersed seeds. The quantity and diversity of dispersed seeds drastically decreased under predation risk for both mesocarnivore's species. Seed dispersal by stone martens was negatively affected by the presence of lynx, with a marked reduction in the number of scats with seeds (93%) and the diversity of dispersed seeds (46%). Foxes dispersed 68% fewer seeds in open habitats when coexisting with lynx, probably leading to differential contributions to seed‐dispersal effectiveness among habitats. Our study reveals a novel trophic cascade from apex predators to plant communities. The behavioural responses of frugivorous mesocarnivores to predation risk and the reduction in the intensity of their faecal deposition pattern are probably related to their lower abundance when co‐occurring with apex predators. While rewilding apex predators is a successful conservation tool, attention should be paid to cascading effects across food webs, particularly where frugivore megafauna is missing and mesocarnivores provide unique services to plants. Read the free Plain Language Summary for this article on the Journal blog.

The role of sheltered habitats in biodiversity conservation of species sensitive to drought: a case study using ground beetles (Coleoptera, Carabidae) in the Gorongosa National Park

AbstractIn the aftermath of 2019’ tropical cyclones Idai and Kenneth, we assessed ground beetle communities of the Gorongosa National Park (GNP) in Mozambique. The influence of habitat shelters, namely the buffering role of closed microhabitat conditions on Alpha diversity and community trait values during a long period of drought, was evaluated across the main habitat types of the park: miombo forests, mixed forests, transitional forests, and grasslands (open savannas). These habitat types comprised a distance gradient in relation to lake Urema, in the center of GNP. Miombo forests were farther from the lake while grasslands and transitional forests were in the floodplain area. Ground beetle communities were sampled using pitfall traps set up at 25 sites of each habitat type along an environmental gradient of tree canopy cover during the last twenty days of the dry season. Higher species richness of ground beetles was found in closed habitat shelters along the distance gradient to lake Urema. A higher functional diversity was also found along the canopy gradient, with larger sized and wingless species being more abundant in closed habitats than in open areas. This result highlights the crucial role of habitat closedness in the protection of sensitive ground beetles. In particular, the buffer effect of tree canopy and the protection of the understory plants and the litter layer was critical for the survival of hygrophilous species and will be key in conservation strategies to face climate aridification and habitat fragmentation.

Multiple‐stressor effects on leaf litter decomposition in freshwater ecosystems: A meta‐analysis

Abstract Recent years have witnessed a surge in research on the effects of multiple stressors in freshwater ecosystems. While studies have increased, the synthesis of their findings into a broader understanding of ecosystem‐level effects remains an ongoing endeavour. Leaf litter decomposition, a frequently investigated and pivotal ecosystem function in freshwaters, is sensitive to changes in abiotic conditions and biotic communities, and therefore susceptible to multiple‐stressor effects. Here, we synthesize findings from 27 manipulative experimental studies encompassing 61 responses of litter decomposition to paired stressors such as warming, nutrient enrichment and emerging pollutants in freshwater ecosystems. We calculated the individual and overall interaction effect sizes resulting from two stressors occurring simultaneously. Furthermore, we analysed the effect of moderator variables in the size and direction of interaction effect sizes using a meta‐analytical approach. Although the vote‐counting method showed additive interactions to dominate individual observations (91.8%), weighted random‐effects meta‐analysis revealed an overall antagonistic interaction between stressors (i.e. the cumulative effect of paired stressors on litter decomposition was less than the sum of their single effects). Our results emphasized the influence of experimental characteristics such as macroinvertebrate involvement, habitat type (lentic vs. lotic) and litter quality (assumed from plant mycorrhizal association) in shaping the responses of litter decomposition to multiple stressors. Our meta‐analysis highlights the need to incorporate local ecological complexities in manipulative experiments to improve predictions of multiple‐stressor effects on biodiversity and ecosystem functions. The present study underscores the importance of considering biotic interactions and adopting the metacommunity framework in conservation and restoration actions to support the management of freshwater ecosystems in an era of rapid global change. Read the free Plain Language Summary for this article on the Journal blog.

Saharo-Sindian endemic flora of Egypt: critical checklist, floristic analysis, habitats, and phytogeographic distribution

The Saharo-Sindian region is characterized by savannas, semi-deserts, and hot deserts. This floristic region includes Morocco, Mauretania, Algeria, Libya, Egypt, Palestine, Kuwait, Saudi Arabia, Qatar, Bahrain, United Arab Emirates, Oman, Yemen, South of Jordan, Syria, Iraq, Afghanistan, Pakistan, in addition to the Sind region. The Sudano-Zambezian region, part of the Paleotropical Kingdom, and the Mediterranean and Irano-Turanian regions, included in the Holarctic Kingdom, share a significant portion of their flora with the studied region. This study initiates the examination of the Saharo-Sindian endemic plants occurring in Egypt. Its objectives include assessing the list of endemic plants within this floristic region, and studying various aspects such as: life forms, habitats, rarity forms, flowering times, dispersal types, and phytogeographical distribution. Twenty field trips were conducted from spring 2020 to September 2023, investigating different regions in Egypt. In addition, all the previous studies performed in the investigated area, scientific literature, and specimens from the region housed in different herbaria have been taken into consideration. The inventory of plants that are endemic to the Saharo-Sindian floristic region in Egypt comprises 126 plant taxa (109 species, 17 subspecies) distributed across 87 genera and 37 families. These endemics are found in 11 habitat types, with the most abundant occurrences observed in inland rocky areas (82 taxa) and temperate shrublands (57 taxa). Moreover, South Sinai stands out as the richest region for Saharo-Sindian endemics, hosting a remarkable 83 taxa, which constitute 65.9% of the total endemics. Among these, the chamaephytes group leads with 56 taxa, followed by the therophytes with 32 taxa. Pogonochores (45 taxa) are the most represented dispersal type. This study holds significant importance in evaluating a critical checklist of plants endemic to the Saharo-Sindian region in Egypt, contributing to our understanding of species diversity in regions facing severe anthropogenic disturbance. This list provides a foundational reference for future monitoring programs.

Rewilding landscapes with apex predators: cheetah (Acinonyx jubatus) movements reveal the importance of environmental and individual contexts

Rewilding landscapes through species or population restoration is an increasingly applied practice in biological conservation. There is expanding interest in wildlife release projects for apex predator population augmentation or reintroductions in historical ranges. Cheetahs (Acinonyx jubatus) are an IUCN Vulnerable-listed species with a declining global population facing major threats, which in southern Africa primarily include lethal persecution on livestock farms and bush encroachment transforming open habitats to woody areas. We used GPS radiocollars to monitor ten adult cheetahs from 2007 – 2018 in the Central Plateau of Namibia encompassing an area restored as an open savanna field (13.7 km2) located in a matrix of woodland savanna affected by bush encroachment. We generated a set of a priori hypotheses that tested the effects of various factors on cheetah movements indexed by step length. We compared cheetah movement metrics based on their history as wild, rehabilitated, and/or translocated individuals. Day/night activity, habitat type, and habitat edges were significant predictors of cheetah movement. Wild resident cheetahs displayed significantly longer steps than the other cheetah classes, possibly suggesting increased territorial behaviour in response to the presence of introduced cheetahs. Some cheetahs temporally segregated by moving extensively during daytime, but most individuals were primarily active during crepuscular periods. Small prey remained constant across time, whereas large prey declined over the study period. Cheetahs appeared to adjust behaviourally by increasing movements in years when large prey were scarce. Cheetahs appeared to be ecologically adaptable and behaviourally flexible in response to varying prey populations and when translocated to new environments, specifically at the interface between bush-encroached woodland and open savanna. Environmental settings and animal history need to be carefully considered in rewilding and ecosystem restoration, and monitoring of released and resident individuals, if present, is important to understand ecological dynamics at release sites.

Spatial structure imposes sex-specific costs but does not reduce interlocus sexual conflict

Abstract Spatial structure is a common feature of all naturally occurring populations. Theoretically, spatial structuring of a habitat could modulate the intensity of interlocus sexual conflict (ISC) in a population, possibly by modulating intersexual encounter rate. We tested this theory using laboratory populations of Drosophila melanogaster by measuring male-induced decline in female fitness in three-patch habitat systems with two alternative habitat types: structured–interconnected and unstructured. Our results on reproductive and survival costs in females suggested significant costs attributable to male presence (i.e. ISC) and to living on structured habitat. However, there was only weak evidence supporting the theory of modulation of ISC by habitat structuring only. Through a follow-up experiment, we also showed that the effect of habitat on ISC is robust to the alteration of female conditions. Therefore, it appears that spatial structuring per se is unlikely to modulate ISC but can impose additional survival costs. We also showed that this survival cost could be sex specific, possibly reflecting female-biased spontaneous dispersal.

MANAGEMENT PLAN FOR RECREATIONAL FISHING IN THE HYDROGRAPHIC ÂNCORA RIVER BASIN

This work is the result of the most recent studies carried out by the ICNF in the drainage basin of the future recreational fishing area (ZPL) of the Âncora river. These supported the design of a plan for the sustainable management and exploitation of recreational fishing in this river basin, which is part of the Minho and Lima Hydrographic Region (RH1). Seven sampling stations were set up for this purpose. Six in the main watercourse and one in the Regueiro dos Enxurros, in the middle of an area of successive waterfalls, just before its confluence with the Regueiro da Lapa Ladrão, which is considered to be the source of the Âncora River. At these stations, hydromorphological quality assessments were carried out on 500 m stretches using the River Habitat Survey (RHS) methodology and fish community monitoring (three per station, for a total of twenty-one inventories) using the electrofishing technique. The results made it possible to consider implementing more sustainable management and exploitation measures for fishing in these continental bodies of water. In this context, the management options took marked account of conservation objectives associated with the presence of European eels (Anguilla anguilla) and red eels (Achondrostoma spp.), the wide distribution of trout (Salmo trutta) and the reduced presence of boga (Pseudochondrostoma duriense) whose distribution in the upper third of this drainage basin is conditioned by a very peculiar geomorphology, filled with numerous slopes, which give rise to beautiful waterfalls. With the information collected, data on the age, growth and physical condition of the ichthyofauna assessed was studied, and their relationship with the different types of habitat in which they occurred was established. The results show that these are watercourses with "Excellent" quality habitats, but with levels of artificialization ranging from "severely modified" to "predominantly unmodified", the result of anthropogenic actions over time. Trout (Salmo trutta) are the most widely distributed species along the main watercourse. The absence of exotic aquaculture species in the samples and the lack of medium to large water impoundment structures in the hydrographic network evaluated should be emphasized. The existing river compartmentalization is materialized by the numerous micro-weirs (many of which allow aquatic organisms to migrate for a good part of the year) and a few waterfalls (natural cascades) that prevent fish from passing through. The trout show isometric growth for all the sampling stations, a balanced physical robustness and a maximum lifespan of 6 years. As a practical result of this study, a Recreational Fishing Management and Exploration Plan for the Âncora River will be created, which will support the design of measures to promote the sustainable management of recreational fishing in the area of the future LPZ, reconciling this activity with nature conservation objectives.

Time and habitat structure shape insect acoustic activity in the Amazon.

Insects are the most diverse animal taxon on Earth and play a key role in ecosystem functioning. However, they are often neglected by ecological surveys owing to the difficulties involved in monitoring this small and hyper-diverse taxon. With technological advances in biomonitoring and analytical methods, these shortcomings may finally be addressed. Here, we performed passive acoustic monitoring at 141 sites (eight habitats) to investigate insect acoustic activity in the Viruá National Park, Brazil. We first describe the frequency range occupied by three soniferous insect groups (cicadas, crickets and katydids) to calculate the acoustic evenness index (AEI). Then, we assess how AEI varies spatially and temporally among habitat types, and finally we investigate the relationship between vegetation structure variables and AEI for each insect category. Overall, crickets occupied lower and narrower frequency bands than cicadas and katydids. AEI values varied among insect categories and across space and time. The highest acoustic activity occurred before sunrise and the lowest acoustic activity was recorded in pastures. Canopy cover was positively associated with cricket acoustic activity but not with katydids. Our findings contribute to a better understanding of the role of time, habitat and vegetation structure in shaping insect activity within diverse Amazonian ecosystems. This article is part of the theme issue 'Towards a toolkit for global insect biodiversity monitoring'.

Comparing the Structure of Fish Assemblage among Natural and Artificial Shallow Rocky Habitats

Artificial coastal structures, such as seawalls, breakwaters, and groins, can exert various impacts on the fish communities in the nearby regions. This study focuses on assessing the ecological effects of coastal infrastructure on marine environments, by comparing, at different seasons, the habitat complexity and heterogeneity, as well as their effects on fish assemblages, between the artificial habitat created with the intention of constructing a marina (Puerto Amor) and the natural habitats surrounding the Cabo de la Huerta area in Alicante (Spain). Employing an asymmetric design and examining two temporal and spatial scales, we utilized visual censuses in snorkeling to gauge the abundance and size of fish species, alongside various parameters related to habitat complexity and heterogeneity. The overarching hypothesis is that fish populations associated with artificial habitats will differ in terms of abundance, biomass, species richness, and diversity compared to fish populations associated with natural habitats, due to changes in complexity and heterogeneity. The findings indicate a shift in fish assemblages; for example, the family Labridae showed differences between the two habitat types for several species. These changes were due to the influences of the Posidonia oceanica meadow and algae like Jania rubens; being influenced by biological variables such as Ellisolandia elongata, Oculina patagonica, and Sarcotragus spinosulus; as well as physical variables such as stones, gravel, and blocks. While there is evidence of alteration in fish assemblages due to changes in habitat structure, there is also an increase in richness (9 species/m2) and total abundance and biomass (1000 ind./m2 and 1700 g/m2, respectively) in the artificial habitat. Multivariate analyses reveal that the fish community in Puerto Amor is less homogeneous than the one in the natural habitat. However, these analyses also indicate an overlap between the communities of both habitats, suggesting substantial similarity despite the noted differences. Consequently, although the habitat alteration has impacted fish populations, it has not diminished abundance, biomass, or species richness. In conclusion, the artificial rocky habitat resulting from the construction attempt at Puerto Amor harbor has fish populations with ecological significance and its removal could lead to undesirable impacts in the area, as the fish assemblages have become well established.

Review and meta-analysis of correlates of home range size in bats

Abstract Home range is an ecological concept that affects many aspects of the life of vertebrates and hence understanding how it varies between species is crucial. Mammalian home range size has been linked to body size and diet, but these studies were based predominantly on terrestrial species and most specifically excluded bats. As the only group of flying mammals, bats experience distinctly different constraints on movement, and hence home range. However, despite their diversity, relatively little is known about the home ranges of bats, and this is the first global review assessing correlates of their home range size. Our hypothesis is that home range will be impacted by different ecological conditions experienced by the bats and by the biological traits of the bats themselves. We performed a meta-analysis based on published data for 81 bat species to identify variables that contribute most to home range size. Sex, wing loading, functional group, colony size, dietary class, distance from the equator (latitudinal region), habitat type, and the interaction between habitat type and latitudinal region were all important explanatory variables. Wing loading was positively correlated with home range size—while females, open-air foragers, large colony sizes, and bats in temperate regions consistently had large home ranges. Understanding the correlates of home range has important implications, for example, for bat conservation and for assessing the risk of spillover of zoonotic pathogens from bats to humans and livestock.

Evaluating habitat-specific interference in automated radio telemetry systems: implications for animal movement studies

Automated radio telemetry systems have become a popular and invaluable tool in tracking the activity and movement of wild animals. However, many environmental conditions can hinder accuracy when tracking with this technology. For instance, study sites may contain multiple habitat types, each habitat uniquely affecting the signal strength received from tagged species. To investigate the influence of a structurally diverse study site on an automated radio telemetry system, we conducted this project at a restored and managed pine barren habitat that consisted of a mix of mature pitch pine, treated pitch pine, scrub oak, and hardwood forests. This site, Montague Plains Wildlife Management Area, Montague, Massachusetts, is also a known breeding ground for Eastern whip-poor-will (Antrostomus vociferus). To measure the relationship of radio signal strength with distance across each habitat, we used radio telemetry equipment manufactured by Cellular Tracking Technologies. We produced negative exponential decay functions measuring radio signal strength over distance and tested for differences among habitat types on radio signal strength (RSS). We found that decay function parameters significantly differed by habitat type, prompting us to investigate if accounting for these differences improved location estimate accuracy. To test this, we estimated known locations using trilateration methods with and without habitat calibration. Comparing these tests indicates that habitat-specific adjustments significantly improved location accuracy. Lastly, we visualized estimated RSS-based locations of 1 week of whip-poor-will data and compared them to GPS data generated from the same individual. Previous studies have accounted for types of environmental interference (like elevation) in the field but have avoided incorporating habitat-specific factors by working with node networks covering a relatively small area, but in this study, we examined the potential to scale up for larger areas and in more complex habitats.

Temporal pattern in foraging behaviour of Vanellus malabaricus in relation to different seasons and habitats

This study monitored the temporal pattern of the diurnal foraging behaviour of yellow-wattled lapwing Vanellus malabaricus Boddaert, 1783 (Charadriiformes: Charadriidae) in different seasons (breeding and non-breeding) and habitats (uncultivated, cultivated, ponds and rivers). The focal observation method was employed to investigate the foraging behaviours of yellow-wattled lapwings. Foraging techniques showed non-significant (p = 0.85) variation in different habitat types; however, walk-halt pecking (WHP) was observed to be the most commonly utilized foraging technique across all habitats. Furthermore, foraging success varied significantly in seasons (p <0.05) as well as in habitat types (p <0.05). Due to the availability of ample food items, foraging success reached its peak in uncultivated habitats. We documented considerably high feeding rates in the uncultivated habitat in the breeding season due to the high prey abundance. Additionally, seasons and habitat both greatly affected the rate of walking. Uncultivated habitat represented the highest value of % successful attempts while the lowest value of % successful attempts was recorded in river habitat. Moreover, the % successful attempts were significant (p <0.05) in the breading season as compared to the non-breeding season. Finally, we found substantial (p <0.05) changes in temporal pattern with regard to daily foraging behaviour. The behaviours appear to be bimodal, with morning and evening types for both seasons and habitat types.

Population Abundance and Density Estimates of Poorly Documented Near-Threatened Calabar Angwantibo (Arctocebus calabarensis) in Oban Hills Region.

Population abundance and density estimates play important roles in biodiversity conservation assessment and can lead to prioritization of conservation efforts, strategies, and management. The Calabar angwantibo (Arctocebus calabarensis) is a poorly studied, Near-Threatened nocturnal, arboreal mammal species occurring only in the lowland moist tropical rainforest blocks of southeastern Nigeria and southwestern Cameroon. Like other arboreal nocturnal mammals, there are gaps in knowledge of the distribution and abundance of this species, which may be facing population declines due to habitat loss and hunting. In this study, we investigated the abundance and density of A. calabarensis in the Oban Hills Region of Nigeria. We conducted systematic distance sampling survey along 32 transects in different habitats in a 1227 km of survey efforts. A total of 41 sightings of A. calabarensis were detected, resulting in an abundance of 7345 individuals (95% CI = 1.51-4.37) with an estimated density of 2.57 animals/km2. The estimated population abundance is 6515 individuals in closed-canopy forests and 830 individuals in secondary forests, with encounter rates of 0.52 individual/km2 and 0.60 individuals/km2 in the closed canopy and secondary forest habitats. The global estimates encounter rate of A. calabarensis across the habitat types is 0.33 individuals/km2 and population abundance of 4456 individuals. Our findings indicate that the A. calabarensis populations can adapt to low changes in forest habitat modifications resulting from increasing and widespread forest disturbance by human-dominated activity, which is giving way to forest clearance for agriculture cultivation and infrastructural development. Our findings help to fill a knowledge gap regarding this species and may help establish a baseline for future management, population monitoring, and conservation of the cryptic population of A. calabarensis in Cross-Sanaga Forests.

Diversity of Anopheles Larvae in Toro Local Government Area, Bauchi State, North-East Nigeria

Vector control is a critical element of malaria control programs in Africa. To reduce human exposure to infective Anopheles mosquitoes, most programs rely on methods that kill adult mosquitoes. Therefore, the study on the distribution and abundance of Anopheles larvae in Toro Local Government Area (LGA.), Bauchi State, North-East Nigeria was carried out in July 2013. Five villages were randomly selected for the collection of Anopheles larvae. A total of 988 Anopheles larvae were collected from five habitat types. The paddy habitat recorded the highest abundance of 494(50%) while the canal habitat had the least abundance 53(5.36 %). The mean abundance of Anopheles larvae in relation to gradients of larval habitat to houses showed no significant difference (F9 = 0.434, Adjusted R2 = -0.39, P = 0.885). However, there was a significant difference (F14 = 9.18, Adjusted R2 = 0.65, P = 0.001) in the mean abundance of Anopheles larvae in relation to habitat types. The larval abundance in relation to water depths varied significantly (F13 = 29.61, Adjusted R2 = 0.888, P = 0.001). There was no significant difference (P > 0.05) in larval abundance between still and moving waters; light versus shaded water bodies; and clear versus turbid waters, respectively. In conclusion, the inhabitants of Toro LGA should always clear stagnant water bodies so as to hinder mosquitoes breeding success. Also, larval source management should focus more on paddy habitat in peri-urban agricultural sites when designing intervention programmes in order to control mosquitoes’ larvae.

Determinants of taxonomic, functional, and phylogenetic beta diversity in breeding birds within urban remnant woodlots: Implications for conservation.

Examining beta diversity of animal assemblages in fragmented habitats, which measures variation in species composition among different fragments, is important for understanding the impact of habitat fragmentation on biodiversity. However, relying solely on taxonomic composition may not provide a comprehensive understanding. Incorporating measures of functional and phylogenetic diversities is essential for elucidating the ecological mechanisms underlying changes in community composition. In addition, prevailing studies often prioritize the evaluation of landscape characteristics within fragments as determinants of beta diversity, neglecting differences in habitat type and plant community composition. In this study, we surveyed birds in 26 remnant woodlot patches (ranging from 0.3 to 290.4 ha) in an urban landscape, southwest China, during the breeding season from 2017 to 2022. We recorded 70 bird species (excluding those recorded only once and high-flying birds, including raptors, swallows, and swifts), with the number of species per patch varying from 14 to 56. The overall bird taxonomic and phylogenetic beta diversities were primarily contributed by the turnover component, while functional beta diversity was dominated by the nestedness-resultant component. Patch area and perimeter area ratio significantly influenced the taxonomic, functional, and phylogenetic beta diversities, primarily mediated through the nestedness-resultant component, while inter-patch distance had a significant effect via the turnover component. In addition, there was a considerable correlation of bird taxonomic, functional, and phylogenetic beta diversities with habitat type and woody plant beta diversities, including their respective partitioned turnover and nestedness-resultant components. Our results suggest that bird assemblages in these patches may be regulated by selective extinction, interspecific competition, and environmental filtering. The findings have significant implications for sustainable landscape planning and habitat restoration. Conserving habitat patches of different sizes and maintaining or enhancing habitat heterogeneity between patches can facilitate the persistence of metacommunities.

Impacts of habitat loss and fragmentation on seed dispersal by an Afrotropical bird community in an anthropogenic landscape: Insights from movement models

Habitat loss and fragmentation can affect seed dispersal by impacting seed dispersers' habitat choices, behavior, and movement patterns. Here we studied seed dispersal by an Afrotropical bird community in an anthropogenic landscape in Kenya. We used telemetry data of six bird species, estimated their habitat choices, behavior, and movement patterns in the forest fragments and the matrix. We then integrated our model estimates into a seed dispersal simulation model with multiple artificial anthropogenic landscapes, experiencing different levels of habitat loss and fragmentation. In our simulations, we included two seed disperser groups: forest specialist and habitat generalist birds that moved in the landscape using a mixture-correlated random walk, and encamped and traveled in the different habitat types. Increased habitat loss diminished seed dispersal distances, where seeds carried by forest specialist dispersers suffered a stronger reduction in dispersal distances compared to habitat generalists, and number of seeds deposited in habitat fragments, where fewer seeds were deposited into the fragments by habitat generalist dispersers compared to forest specialists. The effects of habitat fragmentation were similar to but weaker than that of habitat loss, and most apparent at an intermediate level of habitat loss. Other seed dispersal metrics, including spatial extent of seed rain and nearest neighbor distances among seeds, did not show any strong relationships with either habitat loss or fragmentation. Therefore, movement models offer valuable perspectives on how habitat loss and fragmentation can influence seed dispersal patterns, by reliably estimating habitat choices, behavior, and movement patterns of dispersers, and potentially benefiting efforts to conserve this ecological interaction.

Environmental DNA recovers fish composition turnover of the coral reefs of West Indian Ocean islands.

Islands have been used as model systems to study ecological and evolutionary processes, and they provide an ideal set-up for validating new biodiversity monitoring methods. The application of environmental DNA metabarcoding for monitoring marine biodiversity requires an understanding of the spatial scale of the eDNA signal, which is best tested in island systems. Here, we investigated the variation in Actinopterygii and Elasmobranchii species composition recovered from eDNA metabarcoding along a gradient of distance-to-reef in four of the five French Scattered Islands in the Western Indian Ocean. We collected surface water samples at an increasing distance from reefs (0 m, 250 m, 500 m, 750 m). We used a metabarcoding protocol based on the 'teleo' primers to target marine reef fishes and classified taxa according to their habitat types (benthic or pelagic). We investigated the effect of distance-to-reef on β diversity variation using generalised linear mixed models and estimated species-specific distance-to-reef effects using a model-based approach for community data. Environmental DNA metabarcoding analyses recovered distinct fish species compositions across the four inventoried islands and variations along the distance-to-reef gradient. The analysis of β-diversity variation showed significant taxa turnover between the eDNA samples on and away from the reefs. In agreement with a spatially localised signal from eDNA, benthic species were distributed closer to the reef than pelagic ones. Our findings demonstrate that the combination of eDNA inventories and spatial modelling can provide insights into species habitat preferences related to distance-to-reef gradients at a small scale. As such, eDNA can not only recover large compositional differences among islands but also help understand habitat selection and distribution of marine species at a finer spatial scale.