Habitat Structure Research Articles

Behavioral responses to predator and heterospecific alarm calls are habitat-specific in Eurasian tree sparrows

Acoustic communication plays a vital role in predator-prey interactions. Although habitat structure has been shown to affect anti-predator tactics, little is known about how animals vary their behaviors in response to predator calls or heterospecific alarm calls in different environments. Here we used sound playbacks to test the responses of Eurasian tree sparrows (Passer montanus) foraging in harvested/unharvested rice paddy and open residential area. In the first experiment, we tested their behavioral responses to dove calls, male common cuckoo (Cuculus canorus) calls, hawk-like calls mimicked by female common cuckoo, sparrowhawk (Accipiter nisus) calls, and human yell calls produced to scare birds (predator signal playbacks). In the second experiment, we tested their behavioral responses to the Japanese tit’s (Parus minor) territorial songs and alarm calls (heterospecific alarm signal playbacks). Results showed that the tree sparrows had less fleeing in unharvested ripe rice paddy than in harvested rice paddy and open residential area. In predator signal playbacks, call type affected the escape behavior of sparrows in unharvested rice paddy and open residential area but not harvested rice paddy. In alarm signal playbacks, tit alarm calls evoked more fleeing than territorial songs in harvested rice paddy and open residential area but not unharvested rice paddy. These results suggest that anthropogenic habitat changes may influence avian anti-predator tactics.

Body size shapes song in honeyeaters.

Birdsongs are among the most distinctive animal signals. Their evolution is thought to be shaped simultaneously by habitat structure and by the constraints of morphology. Habitat structure affects song transmission and detectability, thus influencing song (the acoustic adaptation hypothesis), while body size and beak size and shape necessarily constrain song characteristics (the morphological constraint hypothesis). Yet, support for the acoustic adaptation and morphological constraint hypotheses remains equivocal, and their simultaneous examination is infrequent. Using a phenotypically diverse Australasian bird clade, the honeyeaters (Aves: Meliphagidae), we compile a dataset consisting of song, environmental, and morphological variables for 163 species and jointly examine predictions of these two hypotheses. Overall, we find that body size constrains song frequency and pace in honeyeaters. Although habitat type and environmental temperature influence aspects of song, that influence is indirect, likely via effects of environmental variation on body size, with some evidence that elevation constrains the evolution of song peak frequency. Our results demonstrate that morphology has an overwhelming influence on birdsong, in support of the morphological constraint hypothesis, with the environment playing a secondary role generally via body size rather than habitat structure. These results suggest that changing body size (a consequence of both global effects such as climate change and local effects such as habitat transformation) will substantially influence the nature of birdsong.

Response of the root anatomical structure of Carex moorcroftii to habitat drought in the Western Sichuan Plateau of China

Main conclusionThe anatomical structures of Carex moorcroftii roots showing stronger plasticity during drought had a lower coefficient of variation in cell size in the same habitats, while those showing weaker plasticity had a higher coefficient of variation. The complementary relationship between these factors comprises the adaptation mechanism of the C. moorcroftii root to drought.To explore the effects of habitat drought on root anatomy of hygrophytic plants, this study focused on roots of C. moorcroftii. Five sample plots were set up along a soil moisture gradient in the Western Sichuan Plateau to collect experimental materials. Paraffin sectioning was used to obtain root anatomy, and one-way ANOVA, correlation analysis, linear regression analysis, and RDA ranking were applied to analyze the relationship between root anatomy and soil water content. The results showed that the root transverse section area, thickness of epidermal cells, exodermis and Casparian strips, and area of aerenchyma were significantly and positively correlated with soil moisture content (P < 0.01). The diameter of the vascular cylinder and the number and total area of vessels were significantly and negatively correlated with the soil moisture content (P < 0.01). The plasticity of the anatomical structures was strong for the diameter and area of the vascular cylinder and thickness of the Casparian strip and epidermis, while it was weak for vessel diameter and area. In addition, there was an asymmetrical relationship between the functional adaptation of root anatomical structure in different soil moisture and the variation degree of root anatomical structure in the same soil moisture. Therefore, the roots of C. moorcroftii can shorten the water transport distance from the epidermis to the vascular cylinder, increase the area of the vascular cylinder and the number of vessels, and establish a complementary relationship between the functional adaptation of root anatomical structure in different habitats and the variation degree of root anatomical structure in the same habitat to adapt to habitat drought. This study provides a scientific basis for understanding the response of plateau wetland plants to habitat changes and their ecological adaptation strategies. More scientific experimental methods should be adopted to further study the mutual coordination mechanisms of different anatomical structures during root adaptation to habitat drought for hygrophytic plants.

Molecular plasticity to ocean warming and habitat loss in a coral reef fish.

Sea surface temperatures are rising at unprecedented rates, leading to a progressive degradation of complex habitats formed by coral reefs. In parallel, acute thermal stress can lead to physiological challenges for ectotherms that inhabit coral reefs, including fishes. Warming and habitat simplification could push marine fishes beyond their physiological limits in the near future. Specifically, questions remain on how warming and habitat structure influence the brain of marine fishes. Here we evaluated how thermal stress and habitat loss are acting independently and synergistically as stressors in a damselfish of the Western Atlantic, Abudefduf saxatilis. For this experiment, 40 individuals were exposed to different combinations of temperature (27°C or 31°C) and habitat complexity (complex vs simple) for 10 days, and changes in brain gene expression and oxidative stress of liver and muscle were evaluated. The results indicate that warming resulted in increased oxidative damage in the liver (p=0.007) and changes in gene expression of the brain including genes associated with neurotransmission, immune function, and tissue repair. Individuals from simplified habitats showed higher numbers of differentially expressed genes, and changes for genes associated with synaptic plasticity and spatial memory. In addition, a reference transcriptome of A. saxatilis is presented here for the first time, serving as a resource for future molecular studies. This project enhances our understanding of how fishes are responding to the combination of coral reef degradation and thermal stress, while elucidating the plastic mechanisms that will enable generalists to persist in a changing world.

Spatial and temporal changes in shorebird habitats under different land use scenarios along the Yellow and Bohai Sea coasts in China

The effect of coastal wetland loss on shorebird habitat in recent years has been widely reported in previous studies. Various coastal wetland conservation and restoration measures have been implemented or will soon be implemented in China. The extent to which these measures will affect the area and structure of coastal wetland habitat in the future remains unclear. Here, we predicted changes in habitat area and structure for 39 common shorebird species along the coasts of the Yellow and Bohai Seas using a cellular automata–Markov (CA-Markov) land use scenario model and a maximum entropy species distribution model, along with terrain factors (slope, aspect, and digital evaluation model) and climate factors (temperature and precipitation) from the Data Centre for Resources and Environmental Sciences at the Chinese Academy of Sciences, land cover maps interpreted using the human–computer interactive method, and citizen science data of shorebird occurrences derived from eBird, Global Biodiversity Information Facility, and Bird Report. We found that shorebird habitat was most abundant along the coasts of Bohai Bay, Laizhou Bay, and Yancheng. The area of habitat decreased and became increasingly fragmented between 2000 and 2020 for more than half of the 39 species. Under the future business-as-usual scenario, the area of shorebird habitat decreased from 2020 to 2050, and the remaining habitat became increasingly fragmented. Under the ecological protection (EP) scenario, habitat loss was mitigated, and habitat connectivity was improved. The area of habitat was lower in 2050 under the EP scenario than in 2000 for most species, especially threatened species, suggesting that the area of habitat will not return to year-2000 levels under the EP scenario. These results emphasize the need to protect remaining shorebird habitats and implement ecological conservation measures to ensure the long-term preservation of coastal wetlands.

Movement, home range, and structural habitat use of the Largemouth Bass complex in two large Texas reservoirs

Movement, home range, and structural habitat use of the Largemouth Bass complex in two large Texas reservoirs

Blood transcriptome analysis of common kestrel nestlings living in urban and non-urban environments

Urbanisation is one of the main anthropogenic forms of land cover affecting an ever-increasing number of wild animals and their habitats. Physiological plasticity represents an important process through which animals can adjust to the novel conditions of anthropogenic environments. Relying on the analysis of gene expression, it is possible to identify the molecular responses to the habitat conditions and infer possible environmental factors that affect the organismal physiology. We have quantified for the first time the blood transcriptome of common kestrel (Falco tinnunculus) nestlings living in urban sites and compared it to the transcriptome of kestrel nestlings inhabiting rural and natural environments. We found mild differences in the expression of genes among sites, indicating adaptability or acclimation of the birds to the urban habitat. We identified 58 differentially expressed genes between urban and natural kestrels, and 12 differentially expressed genes between urban and rural kestrels. The most striking differences among sites involved inflammatory-immunological, metabolic, apoptosis, DNA repair and development genes. In particular, we found that (i) urban kestrel nestlings had higher expression of genes linked to inflammation, repair of DNA damage, or apoptosis than natural kestrel nestlings, and (ii) natural and rural kestrel nestlings had higher expression of genes linked to the development and activation of immune cells, type I interferon response, or major histocompatibility complex than urban kestrel nestlings. Finally, the KEGG enrichment analysis identified the insulin signalling as the main pathway that differed between natural and urban kestrel nestlings. This is one of a limited number of studies on vertebrates that revealed habitat-associated differences in the transcriptome. It paves the way for further in-depth studies on the links between physiological variation and habitat structure at different spatial and temporal scales.

Social interactions and habitat structure in understanding the dynamic space use of invasive wild pigs

Untangling the abiotic and biotic feedback mechanisms driving animal movements and ranges is a core question in ecology, yet progress is hampered by inadequate modelling procedures. Here we show how a recently developed process‐based modelling approach, combining step‐selection functions and individual‐based models, enables a flexible method to infer movement drivers and multi‐scale emergent space use patterns. As a case study, we examine the movement behaviours of a highly invasive social generalist (wild pigs, Sus scrofa) in relation to conspecific space use and multiple land cover types in a complex agricultural landscape, showing that social interactions are predominantly more important to this species than selection for land cover. Thus, animal movement studies should not neglect the effects of sociality when inferring resource driven movements and, crucially, use multi‐scale techniques that incorporate movement processes to untangle drivers of animal space use.

Architectural approach for evaluation of radiation shielding integration in space habitats

NASA HRP considers developing radiation protection for human space flight and surface habitation as one of the critical technologies for successful deep space exploration. Although the danger of radiation exposure is recognized as a potential show-stopper for deep space exploration, and radiation effects on humans are now understood better than before, shielding strategies for different stages of space flight and habitation are still not addressed in a fully comprehensive manner. Habitats and all space structures planning and design are guided by essential requirements and constraints associated with safety, manufacturing and assembly procedures, propellant and construction costs, maintenance, crew and/or passenger satisfaction. This paper reviews radiation shielding options for space habitats and discusses their feasibility in relation to habitability needs, including the potential for outside viewing in distinct types of space habitats. Typically, radiation protection depends on the thickness of the exterior structure that consists of a pressurized shell, multilayer insulation (MLI) and any applied radiation shielding material. The mass of the external protection shell is the primary factor of radiation shielding effectiveness. Nevertheless, using materials with low atomic numbers (e.g., Boron (5), Carbon (6), and H2O) helps to lower secondary radiation hazards. Water, which is rich in hydrogen and has the lowest atomic number, can also be used for other mission needs. Other materials, including biomaterials, can be considered when their inclusion in the structure is possible and appropriate. The paper presents a comprehensive strategy for radiation shielding selection that includes investigation of complications associated with a type of space habitat structure, mission needs, duration, destination, and crew requirements. The approach presented in the paper aims to establish an evaluation methodology for defining the feasibility of the integration of diverse radiation shielding types into habitat structures. The paper summarizes by reviewing radiation shielding proposals with selected case studies including water, regolith, hydrogen-rich polymers, biotechnology, polyethylene/boron nitride composites, and active strategies.

Impacts of fire and prospects for recovery in a tropical peat forest ecosystem

Uncontrolled fires place considerable burdens on forest ecosystems, compromising our ability to meet conservation and restoration goals. A poor understanding of the impacts of fire on ecosystems and their biodiversity exacerbates this challenge, particularly in tropical regions where few studies have applied consistent analytical techniques to examine a broad range of ecological impacts over multiyear time frames. We compiled 16 y of data on ecosystem properties (17 variables) and biodiversity (21 variables) from a tropical peatland in Indonesia to assess fire impacts and infer the potential for recovery. Burned forest experienced altered structural and microclimatic conditions, resulting in a proliferation of nonforest vegetation and erosion of forest ecosystem properties and biodiversity. Compared to unburned forest, habitat structure, tree density, and canopy cover deteriorated by 58 to 98%, while declines in species diversity and abundance were most pronounced for trees, damselflies, and butterflies, particularly for forest specialist species. Tracking ecosystem property and biodiversity datasets over time revealed most to be sensitive to recurrent high-intensity fires within the wider landscape. These megafires immediately compromised water quality and tree reproductive phenology, crashing commercially valuable fish populations within 3 mo and driving a gradual decline in threatened vertebrates over 9 mo. Burned forest remained structurally compromised long after a burn event, but vegetation showed some signs of recovery over a 12-y period. Our findings demonstrate that, if left uncontrolled, fire may be a pervasive threat to the ecological functioning of tropical forests, underscoring the importance of fire prevention and long-term restoration efforts, as exemplified in Indonesia.

Habitat Selection of Three Neotropical Grassland Birds Is Dependent on Vegetation Structure and Resources

Grassland birds are globally imperiled. Those of endemic Neotropical savannas may be particularly threatened as knowledge of the ecology of many species is lacking, restricting our ability to take decisive conservation action. During the dry (non-breeding) season of 2010, we studied the population size, distribution, and habitat associations of the Cock-tailed Tyrant (Alectrurus tricolor), Black-masked Finch (Coryphaspiza melanotis), and Wedge-tailed Grass-finch (Emberiziodes herbicola) across a disturbance-mediated savanna–grassland gradient in Beni, Bolivia. We used distance sampling and surveyed structural and resource-specific habitat features at plots where birds were present versus random locations. Occupancy models identified fine-scale habitat associations. Cock-tailed Tyrant (7.1 ind./km2) specialized on open habitats in areas expected to be heavily inundated in the wet season, avoided trees, and selected tall grassy swards. Black-masked Finch (25.1 ind./km2) occurred across the gradient, associating with tall, forb-rich swards, sparse shrubs, and low levels of fruiting and seeding vegetation. Wedge-tailed Grass-finch (27.9 ind./km2) also occurred across the gradient, particularly associated with tall, forb-rich swards, abundant seeding grasses, and sparse shrubs. Our results offer the first quantitative abundance estimates for these species in Beni, provide vital baselines for future monitoring, and improve knowledge of the ecology and conservation management needs of these species. Importantly, our results suggest that populations of these three grassland birds may be best maintained in heterogenous, mosaic landscapes that can be produced by carefully managed burning and grazing. Further research in the breeding season would facilitate making stronger, more specific management recommendations.

Ponto-Caspian amphipod co-location with zebra mussel beds (Dreissena polymorpha) is influenced by substrate size and population source

The global spread of non-native species is leading to an increasing frequency of multiple co-occurring non-native species. We examined the co-occurrence of the bivalve mollusc Dreissena polymorpha (zebra mussel) with three Ponto-Caspian amphipods (Dikerogammarus villosus, Dikerogammarus haemobaphes, and Chelicorophium curvispinum) across England and Wales in association with in-situ substrate size. For all three amphipod species, substrate grain size where amphipods co-occurred with D. polymorpha was significantly finer than when recorded in isolation. Subsequently, we confirmed this via aquarium experiments. We examined the occurrence of D. villosus with D. polymorpha when present with cobbles, gravel, or sand from three population sources (co-location with abundant D. polymorpha populations, co-location with low populations, and naïve). Experiments demonstrated that D. villosus actively sought shelter on or near D. polymorpha, with their co-location being significantly more prevalent in finer grained substrates (sand > gravel > cobble). The strength of this co-location differed by population source, with those co-located with high D. polymorpha densities demonstrating a greater association. Our analyses and experiments indicate that D. polymorpha may facilitate Ponto-Caspian amphipod establishment in otherwise suboptimal locations, whereby mussel shells provide favourable structural habitat for the amphipods, analogous to the presence of coarse-grained benthic sediment.

Glacier retreat triggers changes in biodiversity and plant–pollinator interaction diversity

AbstractDue to global warming, the worldwide retreat of glaciers is causing changes in species diversity, community composition, and species interactions. However, the impact of glacier retreat on interaction diversity and ecological networks remains poorly understood. An integrative understanding of network dynamics may inform conservation actions that support biodiversity and ecosystem functioning after glacier extinction. Here, we address how glacier retreat affects the frequency, diversity, and complexity of plant–pollinator interactions, both directly and indirectly through biodiversity change. We surveyed flower visitors (pollinators) and analyzed pollination networks across a gradient of 170 years of glacier retreat (Mont Miné glacier, Valais, Switzerland) which ranges from patchy grasslands to closed forests. We reported a strong impact of glacier retreat on both plant and pollinator communities. Notably, the diversity of plant–pollinator interactions was sharply affected by glacier retreat: interaction diversity increased few years after glacier retreat, but it ultimately decreased in late stages dominated by forests. In contrast, we found that plant–pollinator network complexity did not change with glacier retreat. Our results indicate that the development of plant–pollinator networks is a two-phases process. In the first phase, glacier retreat makes space to plant colonization. This initial increase in plant diversity drives the increase in pollinator and interaction diversity. The second phase is characterized by turnover as woody species encroaches and dominates the community, decreasing the diversity of plant species in ultimate instance. The local decrease of plant diversity leads to a local decrease in pollinator and interaction diversity. Slowing down woody encroachment and enhancing flower diversity, which is initially supported by the glacial landscape, may be key strategies for halting the erosion of ecological networks while increasing biodiversity and ecosystem functioning. Our research thus can help resolve the overarching question of how to conserve ecosystems once glaciers are extinct, pointing toward a composite role of both habitat structure and biological functions.

Unveiling the avian community structure, habitat preference, and conservation concerns in the sal forest of central bangladesh

A study on avifaunal diversity was conducted in Bhawal National Park, Gazipur, Bangladesh, from November 2020 to October 2021 using direct field observation. The study area was divided into five sites based on the habitat structure. A total of 138 bird species and 1,808 individuals were directly counted, representing 17 orders and 49 families. The order Passeriformes and the family Cuculidae had the highest number of species. During the winter season, the richness, abundance, and diversity was the maximum (116 species, 1132 individuals, H= 4.151, Ds= 0.976), with resident bird surpassing migratory species. Among the five study sites, the deep forest area exhibited the greatest number of bird species (75 species, H= 3.983, Ds= 0.975) and trees were the used microhabitat for the birds (101 species, 1521 individuals, H= 4.1, Ds= 0.977). Jungle Babbler (Turdoides striata) had the maximum relative abundance and the ten most abundant species constituted 36.7% of total individuals. A total of 25 habitat generalist species was observed using more than one habitat during the study, while the rest were found in single habitat. Among all the bird species, 136 were Least Concern, one was Near Threatened, and one was Data Deficient. Based on the observation status, it was determined that the majority of bird species (97 species, 70.28%) were classified as few, while 25 species (18.11%) were as uncommon, 12 species (8.69%) as common, and 4 species (2.89%) as very common. The area was noted for its widespread use for recreational activities, and the disturbance caused by visitors lacking awareness poses a significant threat to the local bird population and biodiversity.&#x0D; Dhaka Univ. J. Biol. Sci. 33(1): 1-21, 2024 (January)

Rodent communities in a neglected grassland landscape: Investigating species-specific responses of grassland rodents to habitat type and shrub presence

Arid grasslands worldwide are transitioning to scrublands due to shrub encroachment, resulting in habitats with varying shrub cover. Shrubs play a crucial role in grassland ecosystems, offering trade-offs to rodents in terms of visibility, shelter, and food availability, thereby affecting their occurrence and distribution. This study explores the link between habitat characteristics and rodent activity and density, focusing on shrub presence. In the Tirunelveli district of southern India, we measured rodent density and activity across three grassland types with increasing shrub presence. Our findings reveal species-specific responses to shrub density. The Soft-furred rat (Millardia meltada) dominated, showing adaptability to different shrub levels, while the black rat (Rattus Rattus) was least represented. Fine-scale analysis indicates a positive association between shrub presence and rodent captures. Grassland obligate species like the Indian gerbil (Tatera indica) exhibited reduced activity in densely shrubbed sites, whereas semi-arboreal species like the Indian palm squirrel (Funumbulus palmarum) showed increased activity. This study underscores the importance of considering habitat structure in grassland ecosystem management for the conservation of rodent diversity and ecosystem health.

Characterizing landscape fragmentation of Koitobos river sub-basin, Trans-Nzoia, Kenya

The changes in landscape structure and functioning due to unprecedented human interference are hastening across the globe and it is thus a compelling necessity to preserve and restore our ecosystems. This study aimed to characterize levels of landscape fragmentation, habitat structure, driving forces, and perceptions of the residents on the most preferred reconfiguration approaches. The land use/land cover [LULC] change was first determined by interpreting the 1973, 1986, 1995, 2002, 2014, and 2022 Landsat images using the QGIS 3.26 while the selected landscape fragmentation metrics were analyzed using FRAGSTATS 4.2. Forests, shrubs, and grasslands showed a declining trend, except for agriculture, water, and built-up areas, which depicted high increases for the study periods [1973 to 2022]. The landscape of the study area is characterized as progressively fragmenting as signified by high escalated values of patch number [374 %], edge density [7828 %] between 1986 and 2002, contagion [10.3%], and a declined value of Shannon Diversity Index [SHDI] [-17.42%], Shannon evenness index [SHEI] [-25.8 %] and connectedness [-43.3%]. Considering these results, high losses of forests and grasslands coupled with expansive farmlands and built-up areas have led to unprecedented landscape fragmentation From field surveys and oral interviews, this has not only left streams vulnerable to massive sediment loads but has also triggered annual floods which occur during wet months even though change in onset of rainfall seasons was also reported. The findings call for restoration and integrated and sustainable restoration efforts, especially for the forests, grasslands, and riparian corridors along with sustainable urban planning and community-based sensitization on watershed management.

The effect of planting grass filter strips on fishes in agricultural headwater streams

Abstract Grass filter strips (i.e., herbaceous riparian buffers) are a widely used conservation practice in the United States to mitigate the impacts of agriculture on streams and rivers. Yet, only a limited amount of information is available on the effects of grass filter strips on stream fishes and instream habitat conditions and long‐term assessments are rare. The objective of this research was to document the long‐term effects of planting grass filter strips adjacent to channelized agricultural headwater streams on fish community structure and instream habitat. Fishes, instream habitat and riparian characteristics were sampled from three channelized agricultural headwater streams without grass filter strips, three channelized agricultural headwater streams with grass filter strips and two unchannelized streams having forested riparian habitats in central Ohio from spring of 2006 to autumn of 2015. Fish species richness, abundance, darter species richness, per cent darters, sunfish species richness, minnow species richness and per cent headwater fishes did not differ among riparian habitat types. Darter species richness and per cent darters differed annually. Mean water depth, velocity, wetted width, instream habitat diversity, dominant grain size and per cent instream wood did not differ among riparian habitat types. Mean water depth, water velocity, wetted width and instream habitat diversity exhibited annual differences. Additionally, mean riparian width, woody vegetation density and per cent canopy cover were greater in forested streams than the unplanted and grass filter strip streams. Riparian characteristics did not differ annually. The lack of fish community responses 10–13 years after planting grass filter strips is probably due to the lack of corresponding changes in hydrological characteristics, substrate and instream wood amounts. These results suggest that grass filter strips should not be implemented alone but in conjunction with conservation practices that will improve physical habitat quality and water quality.

Microhabitats shape ant community structure in a spatially heterogeneous grassy woodland

AbstractHabitat structure is a key determinant of local animal diversity, with attributes of vegetation such as cover or complexity generating key resources for different species. However, habitat–diversity relationships can vary across spatial scales, and among different taxa and ecosystem types. Here we report on a study of habitat structure and its effects on ant communities at two spatial scales in a temperate grassy woodland characterized by heterogenous tree and grassland cover. We examined species richness and the occurrence of ground‐dwelling ant species at (1) microhabitat scales defined by a triplet of sites comprising open ground, adjacent to a log, and under a tree, each separated by a few meters, and (2) at macrohabitat scales defined by sites grouped into broader vegetation types defined by low or high levels of shrub and tree cover and separated by 100s of meters. We identified 117 species of ant from 41 genera, from a total of 155,004 individuals collected. Ant community composition differed significantly among microhabitats and macrohabitats, but mean species richness only differed at the microhabitat scale where it was the highest under trees and lower adjacent to logs and in open ground. Notably, ant species within the genera Iridomyrmex, Monomorium, and Pheidole displayed a spectrum of microhabitat preferences, highlighting the ecological flexibility within these groups. By contrast, all species of Melophorus preferred open habitat and all species of Camponotus preferred habitat under trees. Our study shows that ant communities in grassy woodlands are structured by vegetation cover and habitat “openness” most strongly at “microhabitat” scales, which is likely due to a distinct combination of thermal and foraging attributes that vary across relatively small distances. Our results also suggest that broad classifications of ants into functional types based on vegetation preference may not be applicable at small scales where species within the same genus can display contrasting preferences. Land management that promotes habitat heterogeneity at small spatial scales may promote species coexistence and benefit ant diversity more than management activities focusing on larger spatial scales within the same ecosystem.

Ecological Status of Treehopper Caresa tuarina in District Hyderabad, Sindh Pakistan

The treehopper, also known as Caresa tuarina, is an intriguing creature with more than a hundred recorded species. Treehoppers are a very diverse group of insects, that play a crucial role in the ecosystem, yet many species remain uncovered in terms of their ecological status. Objectives: To investigate the ecological status of C. taurina and propose conservation strategies to ensure its preservation in the district Hyderabad, Sindh, Pakistan. Methods: Field survey was carried out in different areas of Hyderabad to investigate the habitat and population of C. tuarina. For preservation of C. taurina specie, naphthalene balls and 70% alcohol were used. Environmental factors including temperature, humidity, plant cover, air pressure, soil type, and UV index and habitat structure were noted at each sample location. Results: The collected treehoppers were small size insects, measuring around 8 mm in length. Agricultural areas and riparian zones were shown to be important habitats for C. taurina populations. Different physical characteristics included soil type was lay and whose terrain was plane land; there was a full moon, 34°C in the mean temperature; 27% Mean humidity; 21.22 psig of air pressure; and a moderate UV index. Urbanization, intensified agriculture, pesticide usage, and changes in habitat appropriateness brought on by climate change are the main causes of habitat degradation for populations of C. taurina. Conclusions: It is concluded that population of treehoppers (C. tuarina) mostly found in agriculture and riparian zones. They are facing habitat degradation as a result of urbanization, intensive agriculture, pesticide use, and changes in habitat appropriateness brought on by climate change.

Influence of Ductility on the Performance of Lunar Habitat Structures Under Recurrent Disturbances

This research examines how ductility affects the durability of lunar surface structures against recurring disturbances like moonquakes, micrometeorite impacts, and thermal cycles over an extended period. The structural performance at various levels of ductility was determined by adjusting material parameters and the thickness of a reference multilayered dome structure. Moonquake and micrometeorite impact-induced lateral displacements were estimated using a reduced-order model under a control-oriented dynamic computational modeling framework. The study considered the degradation of the metallic dome’s strength properties over time due to thermal cycles. Fragility curves were generated by assessing the likelihood of reaching three predefined damage levels as a result of multiple hazards. Additionally, a discounted cash flow analysis was conducted to incorporate a financial aspect into the performance comparison. The findings revealed that structures with sufficient ductility capacity have a lower probability of sustaining severe damage or collapsing within a shorter time frame. Hence, having ductile structures in lunar environments is advantageous as it allows the postponement of maintenance and repair actions, thereby conserving scarce resources for more urgent tasks. Moreover, the financial analysis demonstrated that lunar habitats with higher ductile capacities result in larger net present values, offering a higher return on the initial investment.