Habitat Structure Research Articles

Influence of nearest neighbor distance and habitat structure on vigilance behavior

One of the important antipredator benefits of group living for prey species is collective vigilance that enhances early predator detection. Within the group, individuals monitor the behavior of others to gauge the level of risk in the environment. The nearest-neighbor distance is important as the information travels quickly and easily from the nearest individuals. I examined the vigilance behavior of free-ranging chital deer (Axis axis, Gir Protected Area, India) in response to the group size, nearest neighbor distance, and habitat structure (open versus dense vegetation). The vigilance behavior showed a weak negative response to increases in group size. Overall, the vigilance levels were significantly higher for animals that had distant neighbors. There was a significant interaction effect of habitat structure and the nearest neighbor distance on vigilance levels of chitals. However, this effect was only significantly different for individuals living in dense vegetation. Chitals respond more strongly to conspecific vigilance from their nearest companion in the denser mixed forest than open acacia grasslands. The results indicate that nearest neighbor distance and habitat structure interact in determining the vigilance behavior of group living ungulates and transmission of information within a social group.

Challenges and opportunities of the exotic invasive macroalga Rugulopteryx okamurae (Phaeophyceae, Heterokontophyta)

Abstract The invasion of Rugulopteryx okamurae along the southern European coastline is producing significant ecological and socioeconomic impacts. Its rapid proliferation and high adaptability have cause severe ecosystem disruptions, displacing indigenous species and altering habitat structures. Various factors, including favorable environmental conditions and chemical defenses, have contributed to its rapid spread. This situation has prompted urgent interdisciplinary research and the implementation of management strategies. Regulatory frameworks have been established to address its invasive status, aiming to control the bio-invasion. Valorization strategies could contribute to sustainable marine ecosystem management and marine biotechnology advancements. R. okamurae presents a wide variety of valuable molecules in its internal composition, such as alginates, terpenoids or carotenoids, with potential biotechnological applications. Promising results have been obtained using R. okamurae in compost or biostimulants, as supplements in aquafeed or as part of biomaterial to develop eco-friendly products. Some molecules like terpenoids have shown anti-inflammatory properties with applications in the nutraceutical industry. However, significant challenges remain in fully understanding its biology, ecological impacts, and effective control measures. Coordinated efforts among scientists, politicians, companies and stakeholders are essential to mitigate its spread and explore its potential for sustainable resource utilization. The ecological and economic impacts are being studied but there is a still scarce number of studies to follow a strategy of control based in blue and circular economy.

How does optimal prey abundance shape space use by a territorial raptor?

Understanding predator-prey interactions is important to determine the inter-relationships between species. Optimal foraging theory states that predators balance out energy expended with the energy gained from their prey. In the Iberian Peninsula, the European rabbit (Oryctolagus cuniculus) is a key prey species for endangered Bonelli’s eagle (Aquila fasciata). Thus, it is vital to understand how changes in rabbit abundance can influence habitat selection and territory use by Bonelli’s eagle. We studied 11 radio-tagged Bonelli’s eagles in their territories in Catalonia (NE Iberian Peninsula) and analysed the relationship between rabbit relative abundance, habitat selection and territory use of eagles. Rabbit relative abundance varied between territories, with shrublands hosting more rabbits, and eagles preferred shrublands and open areas for foraging and avoided dense forests. Spatial use by territorial eagles correlated positively with rabbit abundance in rabbit-rich territories, thereby supporting the idea that prey availability influences habitat selection. This result confirms optimal foraging strategies given that open habitats including shrublands tended to host more rabbits, thus providing better opportunities for prey detection and capture. Therefore, maintaining rabbit populations and their habitats (i.e., preserving open Mediterranean shrublands) would seem to be crucial for Bonelli’s eagle conservation. Our findings improve our understanding of predator-prey interactions and highlight the relationship between habitat structure, prey abundance and predator behaviour. In addition, our results emphasize the need for targeted conservation strategies designed to safeguard endangered species such as Bonelli’s eagle and maintain ecosystem integrity.

Effects of water and sediment chemistry variables on aquatic macroinvertebrate community structuring in a subtropical Austral river system.

Riverine physical and chemical characteristics are influencing ecosystem integrity while shaping and impacting species richness and diversity. Changes in these factors could potentially influence community structuring through competition, predation and localised species extinctions. In this study, eight sampling sites over multiple seasons were assessed along the streams draining the City of Nelspruit, South Africa, to examine river health based on water and sediment quality, while using macroinvertebrates as bioindicators for pollution. All water variables with the exception for salinity were found to be significantly different among seasons, with sites having significant differences among all water variables. All sediment chemistry variables were also found to be significantly different among sites and seasons, with the exception of K for sites and Zn and Ca for seasons. The PCA factor loadings and two-cluster analysis identified two groupings, i.e. group 1 that consisted of all metals apart from K and Na and group 2 with K and Na metals. A total of 4470 macroinvertebrate taxa were identified, with Crustacea Caridina nilotica and Diptera Chironominae being dominant across seasons, with macroinvertebrate communities being found to be significantly different among sites and seasons. The most common functional feeding groups across sites were the collector-gatherers (52.2%), followed by collector-filters (26.8%), predators (16.4%), scrapers (4.4%) and shredders (0.1%). Boosted regression trees indicated that high variation in species richness occurred with change in resistivity, P, water pH, ORP, conductivity and S concentrations. These results evidence a strong linkage among the sediment, water quality, substratum embeddedness and habitat structure and community structure. It is important to protect the integrity of aquatic ecosystems through effective monitoring due to the increasing water and sediment quality pressures that arise from various anthropogenic activities.

Avian communities show distinct responses to forest-to-bog restoration.

Since the 1990's, attempted restoration of blanket bogs which have been previously afforested with non-native conifers has taken place in Ireland and Britain, with the aim of reinstating hydrological functioning and hence, peatland biodiversity. Here, we assess the conservation benefit of these restoration measures at sites in the west of Ireland, 16-20 years post works, by comparing avian communities between trios of restored (n=6), near-natural (n=6), and afforested (n=6) lowland blanket bogs. We assessed avian community response in terms of differences in the richness and density of all bird species and of Birds of Conservation Concern in Ireland (BoCCI), as well as community composition. We also investigated which structural habitat variables were responsible for variation in community composition among site types. Restoration resulted in no changes in overall species richness and lower overall bird density but importantly, increased BoCCI richness in comparison to afforested sites. In particular, restoration benefited red-listed species, with richness and density of these species being similar to that of near-natural sites. Avian communities of restored sites were variable but more similar overall to those of near-natural than afforested sites, indicating partial restoration success. Changes in conifer cover, dwarf shrub height, deadwood cover, and broadleaf cover explained the majority of variation occurring across site types. These results indicate that the response of avian communities following forest-to-bog restoration is a prolonged process influenced by the evolving habitat structure, which, in turn, is contingent on the effectiveness of hydrological restoration measures, local conditions and ongoing management.

Niche-related processes explain phylogenetic structure of acoustic bird communities in Mexico.

Acoustic communities are acoustically active species aggregations within a habitat, where vocal interactions between species can interfere their communication. The acoustic adaptation hypothesis (AAH) explains how the habitat favors the transmission of acoustic signals. To understand how bird acoustic communities are structured, we tested the effect of habitat structure on the phylogenetic structure, and on the phylogenetic and vocal diversity of acoustic communities in a semi-arid zone of Mexico. From autonomous recordings in three types of vegetation (crop fields, tetecheras, and mesquiteras), which differ in terms of complexity and canopy openness, we evaluated sound attenuation, and estimated metrics of phylogenetic structure and diversity as well as acoustic diversity with the use of two indices. Mesquiteras showed greater vegetation density, more attenuation, more vocal diversity, as well as a phylogenetic structure that tended towards overdispersion, in contrast to crop fields that showed less vegetation density, less attenuation, less vocal diversity and more phylogenetic relatedness, while tetecheras showed intermediate patterns. Phylogenetic structure was explained by vegetation density and excess attenuation. The higher vocal diversity, phylogenetic structure tended towards overdispersion. These results suggest a role for environmental filters in the crop fields, where more closely related species with similar vocal characteristics coexist (supporting AAH), and probably competitive exclusion in the mesquiteras, where more distantly related species coexist, promoting vocal diversity. This study offers information about the influence of habitat on the acoustic community structure, which could inform our understanding of the distribution of species from acoustic perspective.

Landscape influences bat suppression of pine processionary moth: Implications for pest management.

Bats provide important ecosystem services, particularly in agriculture, yet integrating bat management into conservation plans remains challenging. Some landscape features considerably influence bat presence, diversity, and ecosystem service provision. Understanding the relationship between landscape structure, composition, pest suppression, and ecosystem services is crucial. We modelled areas where bats most effectively suppress pine processionary moths (Thaumetopoea pityocampa), considering landscape characteristics to predict ecosystem services and optimise pest suppression in Serra da Estrela, Portugal. Faecal samples collected during fieldwork were analysed for pine processionary moth presence in bat diets. Lasso regression assessed spatial landscape variables to create an "optimal landscape" for predation. Landscape structure and composition influenced pest suppression differently, with the greatest impact within a 5000-m buffer. "Riparian edge" and "tree cover density" were key habitat structure variables supporting bat navigation and access to hunting areas, while "other forest" and "vineyard/orchard" areas were important composition variables. Optimising landscape composition involves incorporating diverse forest within agroforestry systems to enhance pest suppression by creating habitats reflecting bats' foraging preferences. We recommend strategies focusing on riparian edge conservation, selective canopy reduction, and promoting diverse forest compositions. These strategies aim to create mosaic landscapes balancing land uses, fostering optimal conditions for bat foraging. Our study shows edges provide the highest rates of bats-pine processionary moth interactions. However, caution is needed to avoid excessive fragmentation, which may reduce habitat suitability and increase pest presence before effective bat predation. A balanced approach, focusing on edge creation without over-fragmenting the landscape, is key to promoting sustainable pest management.

Ecological dynamics in Banksia aemula woodlands following widespread, anthropogenic wildfires on a world heritage listed island (K'gari), Australia

AbstractThe increased severity and frequency of wildfires are a growing threat to biodiversity globally posing a complex challenge for the management of protected areas. K'gari, a World Heritage‐listed sand barrier island located off the coast of Australia, was extensively burnt in wildfires in 2019 and 2020. Banksia aemula low open woodland (BALOW) is a fire‐adapted ecosystem, and Banksia aemula is the dominant vegetation type on the island. This research explored interactions between vertebrate fauna and flora species richness and structure after fires in the BALOW habitat. We employed camera trapping and vegetation surveys to estimate species richness and habitat structure. We detected 28 fauna and 56 plant species, including two vulnerable species. Fauna species richness differed between sites; the site with the most intense, extensive, and recent fire had the lowest fauna species richness and mammal species richness. In contrast, the site with lower intensity and more frequent historical fires had the highest fauna diversity. The long unburnt site had higher overall tree diversity and reduced shrub diversity. This research further highlights the need for evidence‐based fire management in protected areas and the risk that large‐scale and/or high‐intensity fires may pose to biodiversity even within fire‐adapted ecosystems.

Ecological Predictors of Habitat Occupancy for the Southeastern Beach Mouse

Abstract The federally threatened southeastern beach mouse Peromyscus polionotus niveiventris occupies just a fraction of its former range along Florida’s Atlantic coast, mostly within the 72 km of continuous coastline on federal lands of the Cape Canaveral Barrier Island Complex. Although believed to be caused by loss and degradation of habitat associated with human urban expansion, no precise explanation for the reduction in southeastern beach mouse range is known. We used nine years of winter habitat occupancy survey data for a trend analysis, and a subset of four years to identify key factors influencing occupancy dynamics in coastal habitat throughout the core population. Using a maximum likelihood based model selection approach, we tested evidence for the effects of environmental and anthropogenic factors arranged into four hypotheses related to habitat structure, beach erosion, population isolation, and access to inland habitat. As predicted, sites closer to the primary dune, farther from open water, and with higher elevation had higher initial occupancy than sites with the opposite characteristics. Also as predicted, sites farther from open water, with higher elevation, and more coastal strand, less disturbed ruderal vegetation, and in proximity to oak trees had lower site extinction. Contrary to predictions sites closer to infrastructure (roads, railroads, paved sites), and more isolated by narrow width or unsuitable habitat features also had lower extinction, possibly due to restriction of predator access. A Bayesian analysis showed that annual southeastern beach mouse habitat occupancy was generally high (0.63-0.97) but variable across the 72 km of coastal dune spanning most of the remaining species’ range. Simulation showed that the power of the survey was sufficient to detect a 20% decline between years. This study provides a baseline of knowledge about habitat occupancy dynamics for future monitoring and management of the southeastern beach mouse, and other beach mouse sub-species.

Long-Term Changes in Bird Communities in the Urban Parks of Mar del Plata City, Argentina

Urbanization is related to the loss of biodiversity and alteration of ecosystem processes. However, long-term changes in the southern hemisphere’s bird communities have been scarcely analyzed in urban areas. The general objective of this work was to analyze changes in bird species richness, diversity, and composition in parks located in the urban and suburban landscapes of Mar del Plata City (Argentina) between 2003 and 2018. Additionally, we aimed to analyze whether these changes were associated with an increase in urbanization or with alterations in the parks’ habitat structure. Tree cover showed significantly lower coverage during 2018. The results showed increased species richness and diversity in all parks by 2018. Rarefaction curves showed that the park bird richness did not differ between the landscapes surrounding parks, but the Shannon and Simpson diversities were higher in parks in suburban landscapes than in parks in urban landscapes. The Shannon and Simpson diversities showed higher values in suburban parks during 2018. However, the diversity values were similar between years in parks in urban landscapes. The species composition was significantly different between landscapes and years. Species turnover was the most predominant pattern of species dissimilarity between landscapes, and species nestedness explained the most dissimilarity between years. Nestedness between years was related to the population increase in many bird species in 2018. In conclusion, we observed differences in the park bird communities between years and landscape types. However, the long-term community changes were not associated with an urbanization increase. Instead, the changes in the local bird community were more related to regional bird species population changes associated with climate warming and increased crop cover.

Plant Architecture Optimizes the Trait-Based Description and Classification of Vegetation.

Trait-based approaches offer valuable perspectives for vegetation classification, but functional traits struggle to capture resource allocation among competing plants, showing limitations across scales. This study aimed to introduce plant architecture to enhance trait-based vegetation classification. Based on a forest transect survey along China's eastern coast from 2021 to 2023, data from 32 plots of coastal dwarf forests (CDF), characterized primarily by reduced plant height, and normal noncoastal dwarf forests (NCDF) were obtained. Their community characteristics were quantified, and classification and clustering models assessed the advantages of plant architecture in distinguishing these communities. The results indicated plant architecture traits are more critical for distinguishing different community types than leaf-based functional traits. Additionally, plant architecture traits are effective in clustering plant associations within the same community type. Because plant architectural traits are closely linked to habitat, phylogeny and community structure, providing a comprehensive description of vegetation. In contrast, traditional plant functional traits primarily reflect habitat information related to soil nutrients. Our findings underscore the importance of plant architecture in optimizing trait-based vegetation classification and suggest that variations in the plasticity of plant architecture traits may support the classification of CDF as a distinct vegetation unit.

Linking habitat and population viability analysis models to account for vegetation dynamics, habitat fragmentation, and social behavior of a metapopulation of Florida scrub-jays

Population dynamics and viability are driven by interactions among habitat and species biology. The Florida scrub-jay (Aphelocoma coerulescens) is a declining and Federally Threatened bird species that requires mid-succession habitat of partly open soil surface with mid-height vegetation. This habitat is created and sustained in a dynamic state of vegetation growth and periodic natural (e.g., fire) or managed (e.g., mechanical clearing) disturbances. Florida scrub-jays once occupied open oak scrub habitats across much of peninsular Florida but have been reduced to a few regional metapopulations and scattered isolated remnant populations. Many of these populations are undergoing continuing decline as open scrub is either converted to residential development or transitions into closed pine and oak forests due to fire suppression. Long-term field studies have shown that breeding and survival rates are determined by the quality of the scrub habitat, with the demography influenced by and in turn mediating the social structure. Prior Population Viability Analyses (PVA) that included dependencies of demographic rates on habitat and social structure indicated that the east coast Florida metapopulations were fragmented into remnant protected patches that were too small and isolated to support long-term persistence, even if the remaining habitat area and quality was sustained. Moreover, recent modeling of habitat transitions under various proposed management schemes, in conjunction with implementation of Adaptive Resource Management (ARM), projected that the proportion of optimal habitat will continue to decline. In this study, we integrated these habitat projections within the PVA and found that the Brevard County mainland metapopulation is projected to decline toward extinction unless habitat quality, extent, and connectivity can be improved. Land managers have recently implemented new innovative methods for restoring optimal scrub habitat, identifying potential improvements in habitat connectivity of nearby populations, and translocation methods to increase and reinforce the demographic and genetic integrity of local populations. Our linked habitat-population models project that the combination of such habitat and population management actions can stabilize the metapopulation and achieve long-term viability.

Habitat Stability Modulates Temporal β-Diversity Patterns of Seagrass-Associated Amphipods Across a Temperate-Subtropical Transition Zone.

Identifying drivers that shape biodiversity across biogeographical regions is important to predict ecosystem responses to environmental changes. While β-diversity has been widely used to describe biodiversity patterns across space, the dynamic assembly of species over time has been comparatively overlooked. Insights from terrestrial and marine studies on temporal β-diversity has mostly considered environmental drivers, while the role of biotic mechanisms has been largely ignored. Here, we investigated patterns of temporal variation in β-diversity of seagrass-associated amphipods. We conducted a study in three biogeographical regions across a temperate to subtropical latitudinal gradient (approximately 2000 km, 13° of latitude in total). In each region, we randomly selected three Cymodocea nodosa meadows, totaling nine meadows sampled seasonally (i.e., four times per year) from 2016 to 2018. We partitioned temporal β-diversity into its turnover (i.e., species replacement) and nestedness (i.e., differences in species composition caused by species losses) components and addressed the relative influence of both temporal variation in habitat structure (i.e., biotic driver) and environmental conditions on the observed β-diversity patterns. Our study revealed high temporal β-diversity of amphipod assemblages across the three biogeographical regions, denoting significant fluctuations in species composition over time. We identified species turnover as the primary driver of temporal β-diversity, strongly linked to temporal variability in local habitat structure rather than to regional climatic drivers. Subtropical Atlantic meadows with high structural stability over time exhibited the largest turnover rates compared with temperate Mediterranean meadows, under lower structural stability, where nestedness was a more relevant component of temporal β-diversity. Our results highlight the crucial role of habitat stability in modulating temporal β-diversity patterns on animals associated with seagrasses, stressing the importance of monitoring variations in habitat structure over time for developing management plans and restoration actions in the context of diversity loss and fragmentation of ecosystems.

Effects of invasive alien plants and habitat structure on bird assemblages in a unique lowland forest in eastern Nepal

Abstract Invasive alien species play a major role in biodiversity decline. We studied the impacts of invasive alien plant species (IAPS) on bird assemblages and their habitats in Jalthal Forest, a biogeographically unique lowland remnant forest in eastern Nepal. We surveyed birds by point counts and quantified environmental variables at 89 sites. Observations of 1,373 individuals of 86 species showed that species richness was the highest in wooded grasslands and floodplains and lowest in sal forests invaded by IAPS, whereas abundance was highest in IAPS-invaded forests. Abundance and richness decreased with increasing cover of IAPS, shrub cover and distance to water. The abundance and richness of every feeding guild except omnivores were negatively correlated with IAPS cover. Our results increase our understanding of the impacts of IAPS on birds and clearly indicate the need of controlling IAPS in Jalthal Forest, and thus, are valuable for forest management and biodiversity conservation.

Variation in biodiversity and abundance of functional groups of arthropods along a tropical elevational gradient in Puerto Rico

AbstractElevational gradients represent platforms for exploring the effects of environmental variation on biodiversity. The environmental correlates of these spatial gradients are likely to be modified during the Anthropocene, as species respond to global change drivers including warming and increased frequency of extreme events. We quantified variation in the abundance of four functional groups of canopy arthropods (i.e., folivores, sap‐suckers, detritivores, and predators), as well as in aspects of biodiversity on each of six host‐plant species along two elevational transects in the Luquillo Mountains of Puerto Rico: a mixed forest transect, traversing tabonuco, palo colorado, and elfin forests, and a palm forest transect, comprising only patches dominated by sierra palm (Prestoea acuminata). We expected gradients in arthropod abundance and biodiversity to be host‐tree specific, and for gradients on palm to differ between transects due to a combination of mechanisms associated with host selection, rescue effects, habitat structure, and source pool dynamics. In general, abundance and biodiversity declined with elevation. The ways in which abundance declined with increasing elevation was contingent on host tree identity and on arthropod functional group, whereas all aspects of biodiversity declined with elevation in consistent manners regardless of host tree identity or transect. Similarly, turnover (beta components of biodiversity between sequential elevational strata) did not differ between transects. Decreases in productivity with increasing elevation may be responsible for gradients in abundance or biodiversity. However, host‐specific and functional group‐specific gradients suggest that elevational effects manifest differently depending on tree species identity and resource bases that are consumer specific.

Floristic composition and structure of Dipterocarps habitat in Dramaga Research Forest, Bogor, Indonesia

Floristic composition and structure of Dipterocarps habitat in Dramaga Research Forest, Bogor, Indonesia

Analysis of the Impact of Agriculture and Logging on Forest Habitat Structure in the Ankasa and Bia Conservation Area of Ghana.

Ghana's Ankasa (ACA) and Bia Conservation Area (BCA) are experiencing forest loss due to agricultural conversions. However, there is limited comprehensive analysis of these conversions and their impact on the forest habitat structure in these areas. This study aims to analyse anthropogenic-induced forest habitat loss and fragmentation in the ACA and BCA. Landsat images for the epochs 1980, 2000 and 2020 were pre-processed, and subsets were created using a 5 km buffer of the two conservation areas. The images were classified into forest, agriculture and built-up. The classified images were analysed for landscape pattern changes using patch density (PD), edge density (ED), largest patch index (LPI), landscape shape index (LSI) and aggregation index (AI). The Wilcoxon signed-rank test was used to analyse changes in landscape structure. The results indicate that forest cover in the ACA decreased by 16.4% from 100,941.6 ha in 1980 to 84,410.6 ha in 2020, and in the BCA, it decreased by 14.4% from 70,211.8 to 60,117.36 ha. There was no encroachment from agricultural activities within the conservation areas, but agricultural activities, mainly cocoa expansion, increased within the 5 km buffer, leading to the decline in forest cover. The landscape analysis shows that the forest patches have become fragmented, disjointed and isolated, especially within the 5 km buffer. This is indicated by increased PD, decreased AI, decreased LPI and increased ED. The immediate loss of forest habitat cover in the off-reserve landscape and the significant levels of forest fragmentation, resulting in the loss of forest connectivity, have significant implications for wildlife conservation. Ecological restoration and conservation efforts are needed to reduce this potential impact. Ecologists have recommended transitioning from monoculture cocoa to cocoa agroforestry to improve forest habitat connectivity within adjoining cocoa farms in the landscapes of these conservation areas.

Seafloor sediment microtopography as a surrogate for biodiversity and ecosystem functioning.

Marine soft sediments play crucial roles in global biogeochemical cycles and biodiversity. Yet, with organisms often hidden in the sediment, they pose challenges for effective monitoring and management. This study introduces a novel approach utilizing sediment microtopography as a proxy for ecosystem functioning and biodiversity. Combining field sampling, benthic chamber incubations, and advanced Structure-from-Motion photogrammetry techniques, we investigated the relationships between microtopographic features and various ecological parameters across diverse subtidal habitats. Our findings reveal strong associations between sediment microtopography and environmental variables, benthic fluxes, biodiversity metrics, and community functional traits, with microtopography consistently explaining more than 50% of the variance in the data. This research demonstrates the potential of sediment microtopography as a cost-effective and scalable tool for assessing soft-sediment ecosystem dynamics and informing conservation strategies. By providing insights into the links between habitat structure and ecological processes, this study advances our understanding of marine benthic ecology and opens new possibilities for habitat assessment applications worldwide.

Habitat management interventions for a specialist mid- successional grassland butterfly, the Lulworth Skipper

Evidence-based management is needed to reverse declines in insect abundance. The Lulworth Skipper Thymelicus acteon is a range-restricted and declining species in the UK and northern Europe associated with mid-successional grassland, which presents management challenges because interventions are necessary to prevent long-term habitat deterioration but can result in short-term reductions in quality. In addition, site management should be compatible for the focal species and for wider plant and insect diversity. We conducted factorial experimental management trials to understand effects of cutting and rotovation on the height and structure of vegetation containing the larval host plant Tor-grass Brachypodium rupestre. We monitored vegetation height, B. rupestre cover and plant diversity, and T. acteon larval presence over four years. Rotovation and cutting differed in their effects on habitat structure and larval occupancy relative to controls. Vegetation height and host plant cover, the most important components of habitat quality for T. acteon, were faster to recover to suitable levels on cut plots. However, larval occupancy increased more quickly on rotovated plots, where plant species diversity was also higher. Results suggest that due to initial negative impacts of interventions on T. acteon occupancy, low frequency or low-intensity management, such as managing sections of a site every three years, is advisable. Our results show that rotovation or cutting the sward can be suitable for mid-successional grassland species such as Lulworth Skipper on sites where grazing might be problematic. Rotational grazing or rotovation can maintain suitable conditions for habitat specialist insects requiring a range of different grassland conditions, serving wider conservation goals.

Spatio-temporal patterns of fish acoustic communities in Western Mediterranean coralligenous reefs: optimizing monitoring through recording duration

In this study, we explored the fish acoustic community at two coralligenous sites in Sardinia (Tavolara and Santa Teresa, western Mediterranean Sea) during the summer 2023. Our goal was to understand spatial and temporal patterns of fish acoustic activity on different temporal scales to offer insights for optimizing acoustic monitoring of this crucial ecosystem. We identified seventeen distinct sound types, revealing a diverse acoustic community. Tavolara had higher acoustic richness and abundance compared to Santa Teresa, which may be attributed to site-specific factors such as habitat structure, species composition, or levels of protection. Temporal analysis revealed clear diel patterns, with certain sounds associated with nocturnal or diurnal periods, reflecting the daily rhythms of different species. The study also examined how recording duration influenced acoustic richness, finding that longer recordings (15 minutes per hour and 15 minutes per hour at night) provided a more comprehensive detection of acoustic activity. Additionally, the number of recording days required to detect species richness varied depending on the site. While extended recordings improve the likelihood of detecting rare or sporadic sounds, they also present challenges in data management and equipment maintenance. The study underscores the importance of carefully planning sampling strategies to optimize acoustic monitoring and ensure effective and sustainable ecological research in coralligenous ecosystems.