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Focal plants are considerably affected by their neighbouring plants, especially when growing in heterogeneous soils. A previous study on grasses demonstrated that soil heterogeneity and species composition affected plant biomass and above- and belowground allocation patterns. We now tested whether these findings were similar for forbs. Three forb species (i.e. Spartina anglica , Limonium bicolor and Suaeda glauca) were grown in pots with three levels of soil heterogeneity, created by alternatively filling resource-rich and resource-poor substrates using small, medium or large patch sizes. Species compositions were created by growing these forbs either in monocultures or in mixtures. Results showed that patch size × species composition significantly impacted shoot biomass, root biomass and total biomass of forbs at different scales. Specifically, at the pot scale, shoot biomass, root biomass and total biomass increased with increasing patch size. At the substrate scale, shoot biomass and total biomass were higher at the large patch size than at the medium patch size, both in resource-rich and resource-poor substrates. Finally, at the community scale, monocultures had more shoot biomass, root biomass and total biomass than those in the two- or three-species mixtures. These results differ from earlier findings on the responses of grasses, where shoot biomass and total biomass decreased with patch size, and more shoot biomass and total biomass were found in resource-rich than resource-poor substrates. To further elucidate the effects of soil heterogeneity on the interactions between neighbour plants, we advise to conduct longer-term experiments featuring a variety of functional groups. [ABSTRACT FROM AUTHOR]

Diversity of mosses of a unique and unexplored geographical location in Himalaya, the Pangi valley in Himachal Pradesh, India is investigated. A total of 49 moss species belonging to 21 families have been recorded, including Hedwigia emodica, the detail on the type specimen of which is uncertain and Encalypta vulgaris, a rare moss in the Himalaya. In addition, 13 moss species are new records for Himachal Pradesh. The dominant mosses of the surveyed area are Philonotis and Grimmia, where the latter is frequently found on basic, barren boulders in sunny positions. Among the recorded moss species, 35 are terrestrial, six aquatic, and eight epiphytes. The findings will be useful for forest policies and management of bryophytes conservation in areas which have extreme climatic conditions. [ABSTRACT FROM AUTHOR]

BACKGROUND: Digital X-ray imaging is essential for diagnosing osteoporosis, but distinguishing affected patients from healthy individuals using these images remains challenging. OBJECTIVE: This study introduces a novel method using deep learning to improve osteoporosis diagnosis from bone X-ray images. METHODS: A dataset of bone X-ray images was analyzed using a newly proposed procedure. This procedure involves segregating the images into regions of interest (ROI) and non-ROI, thereby reducing data redundancy. The images were then processed to enhance both spatial and statistical features. For classification, a Support Vector Machine (SVM) classifier was employed to distinguish between osteoporotic and non-osteoporotic cases. RESULTS: The proposed method demonstrated a promising Area under the Curve (AUC) of 90.8% in diagnosing osteoporosis, benchmarking favorably against existing techniques. This signifies a high level of accuracy in distinguishing osteoporosis patients from healthy controls. CONCLUSIONS: The proposed method effectively distinguishes between osteoporotic and non-osteoporotic cases using bone X-ray images. By enhancing image features and employing SVM classification, the technique offers a promising tool for efficient and accurate osteoporosis diagnosis. [ABSTRACT FROM AUTHOR]

Increasing agricultural intensification, combined with land transformation and fragmentation, poses significant threats to biodiversity. While extensively cultivated landscapes serve as vital refuges against biodiversity loss, they are modified by land abandonment and intensification. Orchard meadows in Central Europe represent traditional extensive land management systems, exhibiting high biodiversity. Comprising cultivated grasslands and scattered fruit trees, orchard meadows feature structures rich in different habitats supporting a diverse flora and fauna. However, their decreasing economic importance in recent decades has resulted in severe degradation or abandonment. Despite their importance for biodiversity conservation, there remains no comprehensive overview of orchard meadow biodiversity and management in Central Europe. This review aims to summarize existing knowledge on orchard meadows' role in biodiversity conservation and the effects of management practices on habitat diversity and quality at both smaller (structure and microhabitats, local scale) and larger scales (surrounding landscape, regional scale). The first part focuses on orchard meadow biodiversity, including both plants and animals and their link to landscape-scale factors. Biodiversity in orchard meadows is predominantly affected by patch size, determining species richness and composition, and connectivity to neighbouring orchard meadows, influencing species migration and recolonization success. The second part evaluates management impacts, illustrating differences in the benefits of mowing versus grazing across taxonomic groups. An intermediate management intensity for orchard meadows determines their conservation value in terms of species composition, varying among different taxonomic groups. To prevent area loss and abandonment of orchard meadows, we advocate for political and public support, along with incentives for farmers to maintain their biodiversity. [ABSTRACT FROM AUTHOR]

The spatial distribution of flowers has important impacts on pollinator movement and foraging decisions. For example, it is well established that bumble bees typically visit larger plants at a higher rate per plant, but the visit rate per flower typically declines as the number of flowers increases. However, much less is known about how honey bee foraging patterns are influenced by plant size and flower number, despite honey bees' importance as agricultural pollinators and their strong competitive impact on other bees. Using a combination of field observations and manipulative experiments with two different wild plant species, we confirmed that honey bees visit larger plants at a higher rate, not only per plant but also per inflorescence. This foraging pattern seems surprising, because it means that there is greater forager density and thus competition for resources on larger plants. We examine three hypotheses to explain why honey bees might nevertheless preferentially visit floral resources on larger plants: (1) larger plants are more salient, making them easier to find and advertise; (2) larger plants offer greater nectar rewards, making visits to them more worthwhile; (3) larger plants have more densely packed flowers, so they are less costly to navigate. We found that honey bee visit rates were indeed influenced by the costs and rewards of their local foraging experience, but the total number of flowers on the plant still positively affected visit rate even when controlling for those local factors. We suggest several ways that the collective foraging strategy of honey bees could lead to an aggregation of foragers on plants with more flowers and discuss the potential implications for agricultural pollination and wild bee conservation as well as foraging theory. • Honey bee visits/inflorescence were higher for large plants than for small plants. • Honey bees' focus on larger plants may stem from their collective foraging strategy. • Prior work has shown that bumble bee visits/flower typically decrease with plant size. • Variation in plant size may reduce competition between honey bees and native bees. [ABSTRACT FROM AUTHOR]

Public and private flower gardens could be valuable for slowing pollinator decline in urbanized areas, as they can potentially provide crucial foraging and reproductive resources in fragmented landscapes. We conducted surveys of adult butterflies at 26 gardens that contained a majority of native species; we then evaluated how the impervious surface percentage (IS%) surrounding each site and the gardens' local characteristics (garden area, plant species richness, and planting density) influenced butterfly communities. Butterfly diversity and abundance were strongly influenced by interactions between IS% and local characteristics. IS% interacted significantly with plant species richness to affect butterfly species richness (p = 0.027) and also interacted significantly with both garden area (p < 0.001) and planting density (p = 0.001) to affect butterfly abundance. In each of these interactions, increasing IS% had a negative effect on butterfly abundance, but that effect was mitigated by increases in the interacting factor. In all cases, the strength of this mitigation was greater in more urban gardens, i.e. those with higher IS%. For example, while larger gardens always had higher butterfly abundances, this difference was greatest when comparing large urban gardens with small urban gardens. Garden area is also critical; in addition to the interaction with IS%, garden area significantly affected butterfly species richness (p = 0.037). As gardens increased in size, so did butterfly species richness regardless of IS%. Our results show that gardens can positively affect urban butterfly diversity and abundance. Urban conservation efforts should focus on establishing new gardens/habitat patches, as well as increasing the size of currently established gardens. [ABSTRACT FROM AUTHOR]

Soil heterogeneity has been shown to enhance plant diversity, but its effect on grassland productivity is less clear. Even less is known about the effect of plant clumping (intraspecific aggregation) and its potential interaction with soil heterogeneity. The combined effects of soil 3D spatial heterogeneity and species clumping were experimentally studied in grassland mesocosms consisting of four grassland species. These species were planted in three patterns (i.e. completely mixed, clumped by 9 or 36 individuals of the same species) on soils with heterogeneous cells of alternating nutrient‐poor and rich soil differing in size from 0 (mixed soil) to 12, 24, and 48 cm (complete poor or rich mesocosm). Moderate soil cell sizes (12–24 cm) consistently increased whole‐mesocosm aboveground productivity by more than 20%, which mainly originated from the increased growth of the plants growing on the poor soil cells. In contrast, total mesocosm productivity was not affected by species clumping although there were some species‐specific effects, both of clumping and of the interaction of clumping with soil heterogeneity. Our results show that intermediate soil heterogeneity promotes productivity. Clumping can improve the growth of inferior species, thus promoting coexistence, without affecting overall productivity. We found no interaction effect of clumping and soil heterogeneity on productivity at the community level and some minor species‐specific effects. [ABSTRACT FROM AUTHOR]

Recovering anomalous information covered under noise in late gates can enhance airborne transient electromagnetic (ATEM) detection. Conventional denoising mainly comprises filtering and gate correlation-based decomposition algorithms; the former fails to extract anomalies contaminated by noise and the latter relies on the correlation between gates, which may yield false late gate anomalies caused by early large-amplitude anomalies in early gates. In ATEM profiles, the correlation between anomalies in adjacent gates makes the anomalies to be measured to have low-rank characteristics relative to the noise-contaminated profiles; the noise is uniformly distributed in the profiles, which have nonlocal self-similarity. Therefore, the low-rank matrix approximation algorithm is applicable to ATEM data denoising. In this study, an algorithm—noise-whitening-based weighted nuclear norm minimization (NW-WNNM)—is designed to remove ATEM profile noise. First, we analyze the influence of patch size in block matching on anomalous and noisy patches and estimate the profile patch size adaptively. Then, we combine the estimation of noise variance in weighted nuclear norm minimization (WNNM) with the noise whitening of similar patch matrices to reduce the noise interference on the nuclear norm and add a whitening factor in the weight vector to make the soft-thresholding function applicable to the low-rank reconstruction of the whitened matrix. By analyzing the reconstructed low-rank matrix and its feature distribution, compared with WNNM, NW-WNNM can detect the feature information more accurately and eliminate the influence of noise on the nuclear norm. Simulation and field profile results indicate that NW-WNNM is superior to comparison denoising methods. [ABSTRACT FROM AUTHOR]

Abstract Phenotypic plasticity is a main mechanism for organisms to cope with changing environments and broaden their ecological range. Plasticity is genetically based and can evolve under natural selection, such that populations within a species show distinct phenotypic responses to the environment if evolved under different conditions. Understanding how intraspecific variation in phenotypic plasticity arises is critical to assess potential adaptation to ongoing climate change. Theory predicts that plasticity is favored in more favorable but variable environments. Yet, many theoretical predictions about benefits, costs, and selection on plasticity remain untested. To test these predictions, we took advantage of three genetic trials in the northern Rocky Mountains, USA, which assessed 23 closely located Pinus ponderosa populations over 27 years. Mean environmental conditions and their spatial patterns of variation at the seed source populations were characterized based on six basic climate parameters. Despite the small area of origin, there was significant genetic variation in phenotypic plasticity for tree growth among populations. We found a significant negative correlation between phenotypic plasticity and the patch size of environmental heterogeneity at the seed source populations, but not with total environmental spatial variance. These results show that populations exposed to high microhabitat heterogeneity have evolved higher phenotypic plasticity and that the trigger was the grain rather than the total magnitude of spatial heterogeneity. Contrary to theoretical predictions, we also found a positive relationship between population plasticity and summer drought at the seed source, indicating that drought can act as a trigger of plasticity. Finally, we found a negative correlation between the quantitative genetic variance within populations and their phenotypic plasticity, suggesting compensatory adaptive mechanisms for the lack of genetic diversity. These results improve our understanding of the microevolutionary drivers of phenotypic plasticity, a critical process for resilience of long‐lived species under climate change, and support decision‐making in tree genetic improvement programs and seed transfer strategies.

The arrangement of plant species within a landscape influences pollination via changes in pollinator movement trajectories and plant–pollinator encounter rates. Yet the combined effects of landscape composition and pollinator traits (especially specialisation) on pollination success remain hard to quantify empirically.We used an individual‐based model to explore how landscape and pollinator specialisation (degree) interact to influence pollination. We modelled variation in the landscape by generating gradients of plant species intermixing—from no mixing to complete intermixing. Furthermore, we varied the level of pollinator specialisation by simulating plant–pollinator (six to eight species) networks of different connectance. We then compared the impacts of these drivers on three proxies for pollination: visitation rate, number of consecutive visits to the focal plant species and expected number of plants pollinated.We found that the spatial arrangements of plants and pollinator degree interact to determine pollination success, and that the influence of these drivers on pollination depends on how pollination is estimated. For most pollinators, visitation rate increases in more plant mixed landscapes. Compared to the two more functional measures of pollination, visitation rate overestimates pollination service. This is particularly severe in landscapes with high plant intermixing and for generalist pollinators. Interestingly, visitation rate is less influenced by pollinator traits (pollinator degree and body size) than are the two functional metrics, likely because 'visitation rate' ignores the order in which pollinators visit plants. However, the visitation sequence order is crucial for the expected number of plants pollinated, since only prior visits to conspecific individuals can contribute to pollination. We show here that this order strongly depends on the spatial arrangements of plants, on pollinator traits and on the interaction between them.Taken together, our findings suggest that visitation rate, the most commonly used proxy for pollination in network studies, should be complemented with more functional metrics which reflect the frequency with which individual pollinators revisit the same plant species. Our findings also suggest that measures of landscape structure such as plant intermixing and density—in combination with pollinators' level of specialism—can improve estimates of the probability of pollination. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Human activities affect biodiversity by reducing the area of habitats, altering their shape, and increasing their isolation. Ants are particularly sensitive to habitat fragmentation, as it may locally change abiotic conditions, the availability of food and nest sites, the abundance of mutualists, competitors and predators, and also restrict gene flow between patches. As a result, the genetic population and colony structure of ants is expected to show signs of fragmentation. In the present study, we investigated the impact of fragmentation on the ant Temnothorax crassispinus in 45 forest patches across the Franconian Jura, Germany. Based on 283 colonies, of which 156 were genetically analyzed, we evidenced the presence of two putative distinct genetic clusters in the study area. Both the nest densities and the presence of queen were impacted by the number of adjacent forest patches within 400 m around the focal patch, but neither by patch shape nor patch size. We could not detect any effect of fragmentation on the genetic diversity, probably because the high dispersal abilities of T. crassispinus counterbalance any detrimental genetic consequences of fragmentation. Nevertheless, fragmentation still impacts the species density as well as the social structure of its colonies. Further investigations regarding the drivers of occurrence at a finer spatial scale might clarify the role of edge effects on the occurrence of this species. [ABSTRACT FROM AUTHOR]

Significantly higher population densities of a squash pest beetle, Acalymma vittatum, were observed in a squash monoculture than a triculture of squash, maize, and beans. One hypothesis for such differences is that non‐host plants in the triculture cause the herbivore to move more frequently resulting in higher emigration rates from the tricultures. Plant to plant movement of the beetle was studied in vegetative winter squash to evaluate if differences in components of trivial movement would generate a higher emigration rate from the triculture. Tenure times were shorter on plants in the triculture than on plants in the squash monoculture, there was no movement directionality, movement distances were greater in squash monocultures than in tricultures and were greater during July than August. In the tricultures, plant‐to‐plant transitions were primarily to maize from non‐host plants and to beans or squash from host plants during July, but during August, movement from any plant was primarily to maize. We integrated the values of the movement components from vegetative winter squash into a simple Markov model, and found that during July, emigration was estimated to be faster from the triculture than the monoculture, supporting the hypothesis. However, in August, emigration was estimated to be slower from the triculture. In August, maize plants were tall and, by acting like a fence, greatly reduced the movement distance of beetles. The effect of the differences in emigration rate on beetle population density was greatest for small patches, indicating that emigration may be important only in small‐scale production systems. [ABSTRACT FROM AUTHOR]

The creeping perennial weed species Cirsium arvense (L.) Scop. occurs in patches. Expanding creeping roots allow these patches to increase their covered area. This characteristic has rarely been addressed when investigating the effects of control options in arable fields. We designed a three-year field experiment (2019–2021) in north-eastern Germany, accounting for existing patch patterns. The experimental setup included an untreated control, a competition treatment (cover crop, CC), two disturbance treatments by mouldboard ploughing (PL), root cutting (RC), and four combined applications (RC + CC, PL + CC, PL + RC, PL + RC + CC). Root cutting was performed by a prototype tillage machine produced by "Kverneland". Plots were defined by the species growth pattern and mapped by GPS and UAV. The experiment investigates the thistle response variables: "Expansion", "Density", "Coverage", and "Height". Treatments including disturbance by ploughing (PL, PL + CC, PL + RC, PL + RC + CC) reduced "Density" by the factor 0.15 and "Expansion" by 0.25, while those without ploughing (CC, RC, RC + CC) only reduced "Density" by the factor 0.68 and "Expansion" by 0.71. Adding root cuttings or cover crops did not further increase the reduction effect of ploughing. Treatments with competition by cover crops impacted "Expansion" more clearly than "Density". When cover crops were combined with root cutting (RC + CC), "Expansion" was almost additively reduced, resulting in a reduction comparable to that of ploughing. The "Height" of the shoots was significantly reduced in four treatments (PL, RC + CC, PL + RC, PL + RC + CC), while "Coverage" did not change significantly. UAV patch monitoring proved to be accurate enough for thistle "Expansion" but not for thistle "Density" within the patch. The results of this study demand innovative research when controlling patch-forming creeping perennial weeds. The need for patches will limit small-scale experimental set ups. [ABSTRACT FROM AUTHOR]

Fragmentation and scale: Although habitat loss has well‐known impacts on biodiversity, the effects of habitat fragmentation remain intensely debated. It is often argued that the effects of habitat fragmentation, or the breaking apart of habitat for a given habitat amount, can be understood only at the scale of entire landscapes composed of multiple habitat patches. Yet, fragmentation also impacts the size, isolation and habitat edge for individual patches within landscapes. Addressing the problem of scale on fragmentation effects is crucial for resolving how fragmentation impacts biodiversity. Scaling framework: We build upon scaling concepts in ecology to describe a framework that emphasizes three "dimensions" of scale in habitat fragmentation research: the scales of phenomena (or mechanisms), sampling and analysis. Using this framework, we identify ongoing challenges and provide guidance for advancing the science of fragmentation. Implications: We show that patch‐ and landscape‐scale patterns arising from habitat fragmentation for a given amount of habitat are fundamentally related, leading to interdependencies among expected patterns arising from different scales of phenomena. Aggregation of information when increasing the grain of sampling (e.g., from patch to landscape) creates challenges owing to biases created from the modifiable areal unit problem. Consequently, we recommend that sampling strategies use the finest grain that captures potential underlying mechanisms (e.g., plot or patch). Study designs that can capture phenomena operating at multiple spatial extents offer the most promise for understanding the effects of fragmentation and its underlying mechanisms. By embracing the interrelationships among scales, we expect more rapid advances in our understanding of habitat fragmentation. [ABSTRACT FROM AUTHOR]

Optimal foraging theory has guided much of the research on foraging behaviour in the past five decades, with the notion of optimality deeply embedded in most models today. However, assuming that all foragers strive to maximize a certain predefined currency, such as amount of food per unit time, restricts what can be learned about the factors influencing foraging decisions. Here we applied a different approach: the discrete-choice model, which does not assume an optimal strategy as the starting point, but instead examines foraging decisions directly, modelling interpatch movements as the consequence of a choice of destination from a limited set of options. We analysed a set of foraging decisions by both adult male and female chimpanzees, Pan troglodytes , from two habituated communities in the Budongo forest, Uganda, to investigate the influence of foraging variables including food patch characteristics and interpatch distance on patch choice, with a view to identifying the strategy underlying these decisions. Despite differences in habitat between communities, we found that foraging strategies were remarkably similar across both communities and sexes, with chimpanzees exhibiting a clear preference for closer and novel (not previously visited) food patches. Individuals of both communities frequently chose to forage on food patches providing young leaves, highlighting the importance of this food type in their diet. Contrary to expectation, patch size did not predict foraging decisions, except for adult males of one community that chose larger patches, while both sexes aimed to minimize travel distance between consecutive patches. This study provides the first direct evidence that chimpanzees consider travel distance and whether they have recently visited a patch when choosing between potential foraging sites and demonstrates that new insights can be gained (even in a well-studied system) from integrating several important variables describing feeding ecology into a coherent model of patch choice. • Discrete-choice models facilitate direct investigation of animal foraging strategies. • Chimpanzees consider distance and novelty when choosing foraging patches. • Patch size had no impact on choice of patch by adult female chimpanzees. • Both male and female adult chimpanzees aim to minimize travel distance. [ABSTRACT FROM AUTHOR]

Animals commonly exhibit a tendency to return to previously visited locations. Such tendency is manifested at different scales, for example, fidelity to a site or fidelity to a specific patch within a site. Although patch fidelity has important implications for the pollinators and the plants they visit, our understanding of patch fidelity, and the extent to which it varies among bee species, remains limited. Here, we used a mark–reobservation approach to compare patch fidelity and patch size preference between one bumble bee and one honey bee species foraging on patches of Medicago sativa L. Honey bees exhibited greater patch fidelity (76%) than bumble bees (47%); they were more likely to return to the patch where they were marked. Patch size affected the level of patch fidelity for bumble bees but not for honey bees. Bumble bees were more likely to return to larger rather than smaller patches. In addition to patch fidelity, we detected preference of bees for the larger patches. Bees visited the larger patches more often than the smaller patches. These results add patch fidelity to the already known repertoire of differences in foraging strategies between a bumble bee and a honey bee species. It also indicates how the simultaneous study of distinct species in a similar environment can reveal important previously undetected information about their behavioral ecology. Observed differences in patch fidelity and patch size preferences may have important implications for crop pollination and conservation habitat design. [ABSTRACT FROM AUTHOR]

Medical image segmentation, whether semi-automatically or manually, is labor-intensive, subjective, and needs specialized personnel. The fully automated segmentation process recently gained importance due to its better design and understanding of CNNs. Considering this, we decided to develop our in-house segmentation software and compare it to the systems of established companies, an inexperienced user, and an expert as ground truth. The companies included in the study have a cloud-based option that performs accurately in clinical routine (dice similarity coefficient of 0.912 to 0.949) with an average segmentation time ranging from 3′54″ to 85′54″. Our in-house model achieved an accuracy of 94.24% compared to the best-performing software and had the shortest mean segmentation time of 2′03″. During the study, developing in-house segmentation software gave us a glimpse into the strenuous work that companies face when offering clinically relevant solutions. All the problems encountered were discussed with the companies and solved, so both parties benefited from this experience. In doing so, we demonstrated that fully automated segmentation needs further research and collaboration between academics and the private sector to achieve full acceptance in clinical routines. [ABSTRACT FROM AUTHOR]

Abstract Animals commonly exhibit a tendency to return to previously visited locations. Such tendency is manifested at different scales, for example, fidelity to a site or fidelity to a specific patch within a site. Although patch fidelity has important implications for the pollinators and the plants they visit, our understanding of patch fidelity, and the extent to which it varies among bee species, remains limited. Here, we used a mark–reobservation approach to compare patch fidelity and patch size preference between one bumble bee and one honey bee species foraging on patches of Medicago sativa L. Honey bees exhibited greater patch fidelity (76%) than bumble bees (47%); they were more likely to return to the patch where they were marked. Patch size affected the level of patch fidelity for bumble bees but not for honey bees. Bumble bees were more likely to return to larger rather than smaller patches. In addition to patch fidelity, we detected preference of bees for the larger patches. Bees visited the larger patches more often than the smaller patches. These results add patch fidelity to the already known repertoire of differences in foraging strategies between a bumble bee and a honey bee species. It also indicates how the simultaneous study of distinct species in a similar environment can reveal important previously undetected information about their behavioral ecology. Observed differences in patch fidelity and patch size preferences may have important implications for crop pollination and conservation habitat design.

Coastal wetlands provide essential ecosystem goods and services but are extremely vulnerable to sea‐level rise, extreme climate, and human activities, especially the coastal wetlands in large river deltas, which are regarded as "natural recorders" of changes in estuarine environments. In addition to the area (loss or gain) and quality (degradation or improvement) of coastal wetlands, the information on coastal wetland structure (e.g., patch size and number) are also major metrics for coastal restoration and biodiversity protection, but remain very limited in China's four major river deltas. In this study, we quantified the spatial–temporal dynamics of total area (TA) and patch number (PN) of coastal wetlands with different sizes in the four deltas and the protected areas (PAs) and assessed the effects of major driving factors during 1984–2020. We also investigated the effectiveness of PAs through the comparison of TA and PN of coastal wetlands before and after the years in which PAs were listed as Ramsar Sites. We found both TA and PN experienced substantial losses in the Liaohe River Delta and Yellow River Delta but recent recoveries in the Yangtze River Delta. The coastal wetlands had a relatively stable and variable trend in TA but had a continually increasing trend in PN in the Pearl River Delta. Furthermore, reduced coastal reclamation, ecological restoration projects, and rapid expansion of invasive plants had great impacts on the coastal wetland structure in various ways. We also found that PAs were effective in halting the decreasing trends in coastal wetland areas and slowing the expansion of reclamation, but the success of PAs is being counteracted by soaring exotic plant invasions. Our findings provide vital information for the government and the public to address increasing challenges of coastal restoration, management, and sustainability in large river deltas. [ABSTRACT FROM AUTHOR]

Context: Intensive use of agricultural land often modifies the landscape by dividing continuous natural habitat into smaller and more isolated patches. While the effects of habitat fragmentation on species abundance and diversity have been widely studied, little is known about how fragmentation impacts the function of organisms that do persist in the modified environment. Understanding these effects is complicated by the fact that fragmentation can affect organisms directly but also indirectly, by altering the patch microclimatic conditions. Objectives: We tested the hypothesis that fragmentation-induced microclimate change might be an important mechanism driving changes in animal locomotion in an agricultural landscape. Methods: We used satellite image analysis, behavioral assays, and patch analyses, to disentangling the direct and indirect effects of fragmentation on the locomotor behavior of a darkling beetle, Zophosis punctata (Tenebrionidae), in the Southern Judea Lowlands in Israel. Results: We found that fragmentation in an agricultural ecosystem may lead to changes in the thermal conditions of natural habitat patches. Importantly, such fragmentation-related increases in patch temperature played an important role in explaining variation in beetle locomotion across an agricultural landscape. Specifically, beetles from highly fragmented landscapes, which included warmer habitat patches, showed high locomotor intermittence -frequent pausing events during locomotion. Conclusions: This study shows that the potential consequences of habitat fragmentation on organism function are likely to be underestimated when fragmentation-related microclimate change is ignored. Intermittent locomotion, as opposed to steady locomotion, may provide physiological and fitness benefits in fragmented landscapes, like mitigating performance limitations imposed by extreme thermal conditions. [ABSTRACT FROM AUTHOR]

Haze, generated by floaters (semitransparent clouds, fog, snow, etc.) in the atmosphere, can significantly degrade the utilization of remote sensing images (RSIs). However, the existing techniques for single image dehazing rarely consider that the haze is superimposed by floaters and shadow, and they often aggravate the degree of the haze shadow and dark region. In this paper, a single RSI dehazing method based on robust light-dark prior (RLDP) is proposed, which utilizes the proposed hybrid model and is robust to outlier pixels. In the proposed RLDP method, the haze is first removed by a robust dark channel prior (RDCP). Then, the shadow is removed with a robust light channel prior (RLCP). Further, a cube root mean enhancement (CRME)-based stable state search criterion is proposed for solving the difficult problem of patch size setting. The experiment results on benchmark and Landsat 8 RSIs demonstrate that the RLDP method could effectively remove haze. [ABSTRACT FROM AUTHOR]

With past and continued loss of secondary forests in urban areas, this paper aims to assess the current distribution of secondary forests and evaluate the ecological values of secondary forests in terms of patch sizes, plant density and biodiversity values by using the analysis tools of GIS and FRAGSTATS. According to the analysis in this paper, over 1782 ha of secondary forest cover in Singapore has been lost due to the urbanization, such as residential and infrastructure development, in the past decade. It is estimated that about 7331 ha of secondary forests are planned to be cleared for new development. The future loss of secondary forests is about 1.2 times larger than the entire area of all parks and nature reserves in Singapore. It is shown that secondary forests became more fragmented compared with 2011, and more than 80% of patches are smaller than 1 ha. Most of the secondary forests' patches are with high plant density and high biodiversity values in terms of ecological connection. Discussions towards the improvement of biodiversity and phase development planning for secondary forests in a tropical high-density city are addressed in this paper. There is lots of potential to integrate secondary forests into future land use developments for improving biodiversity based on the literature review and analysis results. [ABSTRACT FROM AUTHOR]

Chapman et al.'s (Behav Ecol Sociobiol 36:59–70, 1995) ecological constraints model posits that the size and distribution of food patches place restrictions upon foraging group size. Larger groups incur increased travel costs for any given array of patches, and thus, to fulfil individual energetic and nutritional requirements, foragers should adjust group sizes to balance energy obtained against that spent on travelling. Support for this model comes from both comparative and species-specific studies but findings are contradictory, and the utility of the model has been questioned. This study provides a rigorous test, analysing measurements from distinct food patches and individual inter-patch movements, on an appropriately shorter temporal scale. Using data drawn from two social groups of a species characterised by a high degree of fission–fusion dynamics, the chimpanzee (Pan troglodytes), we show that larger parties foraged in larger food patches and for longer durations, and that larger parties were associated with further travel between patches. Overt contest competition over food increased with party size. We found no evidence of distinct sex differences in either party size or travel distances: the predictive power of forager sex was low compared to that of ecological variables. We propose that analysis at the patch level is more appropriate than a daily averaging approach that may smooth out the very variation being investigated. Our findings suggest that, despite certain limitations, Chapman et al.'s (Behav Ecol Sociobiol 36:59–70, 1995) model of ecological constraints remains a useful tool. Ecology does indeed constrain grouping patterns, and the impact of this is not necessarily differentiated by sex. Significance statement: Foraging animals face the 'more mouths to feed' problem: as the numbers in a group increase, the group must travel further to find enough food, using up energy. Hence, foragers should adjust numbers to minimise these costs, but tests of this idea have proved inconclusive. We investigated the foraging behaviour of chimpanzees, a species with highly flexible grouping, considering their travel between specific patches of food. We found clear support for this proposition, with larger patches of food hosting larger numbers of foragers, and such groups having to travel further to find food. Although it is often thought that female animals should respond more strongly to foraging costs, we found little evidence of sex differences. Our results show that ecology does indeed constrain grouping patterns, and that the impact is felt equally by males and females. [ABSTRACT FROM AUTHOR]

Modern hyperspectral sensors provide a huge volume of data at spectral and spatial domains with high redundancy, which requires robust methods for analysis. In this study, 2D and 3D CNN models were applied to hyperspectral image datasets (ROSIS and Jilin-1 GP01) using varying patch and sample sizes to determine their combined impacts on the performance of deep learning models. Differences in classification performances in relation to particle and sample sizes were statistically analysed using McNemar's test. According to the findings, raising the patch and sample size enhances the performance of the 2D/3D CNN model and produces more accurate results in the classification of hyperspectral imagery. To be more specific, the thematic maps produced with 400 and 600 samples resulted in a notable increase in overall accuracies (approximately 10%) compared to 50 and 100 samples per class. Statistical test results confirmed the importance of patch size selection for the case of limited training data and the maximum number of samples required for deep learning. It could be also mentioned that an appropriate patch and sample size should be selected considering the characteristics of the dataset and the type of deep learning algorithms. [ABSTRACT FROM AUTHOR]

Spartina anglica (hereafter Spartina) is an invasive perennial marsh grass shifting hydrodynamic regime and sediment characteristics in invaded area, thereby reducing macrobenthic diversity. There have been only a few studies focusing on the patch structure of Spartina according to size and its effects on macrofauna. A field experiment was conducted to identify effects of Spartina patches where they have been introduced no later than 5 years after invasion occurred on macrofauna assemblages in Ganghwa Island, South Korea. The survey area was divided into two sections according to vegetation: (1) Suaeda japonica vegetation from 0 to 60 m away from the levee, and (2) bare mudflat from 60 to 90 m away from the levee. The patch sizes of Spartina were categorized into small (1–4 m2), medium (5–11 m2), and large (13–40 m2) in area with four replicates for each section. The biomass ratio of the belowground and aboveground in the small size patch of Spartina was significantly higher than those in the medium and large size patch of Spartina. It indicated that more resource was allocated to rhizomes in small size patch with short invasion history (1 ~ 2 years). After Spartina invaded, macrofauna richness (70%), Shannon–Wiener diversity (80%), and density (67%) were decreased. However, infaunal deposit-feeding polychaete Perinereis linea and epifaunal gastropods Batillaria cumingi and Lactiforis takii increased by Spartina. Ordination of macroinvertebrate assemblages separated the habitat with Spartina invasion from the adjacent uninvaded tidal flat and Suaeda japonica habitats. This study offers a significant insight into early invasion strategies of an aggressive plant invader, Spartina for management of coastal wetlands and its impacts on macrofaunal assemblages. [ABSTRACT FROM AUTHOR]

Phenotypic plasticity is a main mechanism for organisms to cope with changing environments and broaden their ecological range. Plasticity is genetically based and can evolve under natural selection, such that populations within a species show distinct phenotypic responses to the environment if evolved under different conditions. Understanding how intraspecific variation in phenotypic plasticity arises is critical to assess potential adaptation to ongoing climate change. Theory predicts that plasticity is favored in more favorable but variable environments. Yet, many theoretical predictions about benefits, costs, and selection on plasticity remain untested. To test these predictions, we took advantage of three genetic trials in the northern Rocky Mountains, USA, which assessed 23 closely located Pinus ponderosa populations over 27 years. Mean environmental conditions and their spatial patterns of variation at the seed source populations were characterized based on six basic climate parameters. Despite the small area of origin, there was significant genetic variation in phenotypic plasticity for tree growth among populations. We found a significant negative correlation between phenotypic plasticity and the patch size of environmental heterogeneity at the seed source populations, but not with total environmental spatial variance. These results show that populations exposed to high microhabitat heterogeneity have evolved higher phenotypic plasticity and that the trigger was the grain rather than the total magnitude of spatial heterogeneity. Contrary to theoretical predictions, we also found a positive relationship between population plasticity and summer drought at the seed source, indicating that drought can act as a trigger of plasticity. Finally, we found a negative correlation between the quantitative genetic variance within populations and their phenotypic plasticity, suggesting compensatory adaptive mechanisms for the lack of genetic diversity. These results improve our understanding of the microevolutionary drivers of phenotypic plasticity, a critical process for resilience of long‐lived species under climate change, and support decision‐making in tree genetic improvement programs and seed transfer strategies. [ABSTRACT FROM AUTHOR]

Abstract Patch size is one of the most important factors affecting the distribution and abundance of species, and recent research has shown that patch size is an important niche dimension affecting community structure in aquatic insects. Building on this result, we examined the impact of patch size in conjunction with presence of larval anurans on colonization by aquatic insects. Hyla chrysoscelis (Cope's gray treefrog) larvae are abundant and early colonists in fishless lentic habitats, and these larvae can fill multiple ecological roles. By establishing larvae in mesocosms prior to colonization, we were able to assess whether H. chrysoscelis larvae have priority effects on aquatic insect assemblages. We conducted a series of three experiments in naturally colonized experimental landscapes to test whether (1) H. chrysoscelis larval density affects insect colonization, (2) variation in patch size affects insect colonization, and (3) the presence and larval density of H. chrysoscelis shift colonization of insects between patches of different size. Larval density independently had almost no effect on colonization, while patch size had species‐specific effects consistent with prior work. When larvae and patch size were tested in conjunction, patch size had numerous, often strong, species‐specific effects on colonization; larval density had effects largely limited to the assemblages of colonizing beetles and water bugs, with few effects on individual species. Higher larval densities in large mesocosms shifted some insect colonization to smaller patches, resulting in higher beta diversity among small patches in proximity to high density large mesocosms. This indicates establishing H. chrysoscelis larvae prior to insect colonization can likely create priority effects that slightly shape insect communities. Our results support the importance of patch size in studying species abundances and distributions and also indicate that colonization order plays an important role in determining the communities found within habitat patches.

Diversity in habitat patches is partly driven by variation in patch size, which affects extinction, and isolation, which affects immigration. Patch size also affects immigration as a component of patch quality. In wetland ecosystems, where variation in patch size and interpatch distance is ubiquitous, relationships between size and isolation may involve trade‐offs. We assayed treefrog oviposition at three patch sizes in arrays of two types, one where size increased with distance from forest (dispersed) and one with all patches equidistant from forest (equidistant), testing directly for an interaction between patch size and distance, which was highly significant. Medium patches in dispersed arrays received more eggs than those in equidistant arrays as use of typically preferred larger patches was reduced in dispersed arrays. Our results demonstrated a habitat selection trade‐off between preferred large and less‐preferred medium patches across small‐scale variation in isolation. Such patch size/isolation relationships are critical to community assembly and to understanding how diversity is maintained within a metapopulation and metacommunity framework, especially as wetland habitat becomes increasingly rare and fragmented. These results bring lessons of island biogeography, writ large, to bear on questions at small scales where ecologists often work and where habitat restoration is most often focused. [ABSTRACT FROM AUTHOR]

Context: Several plant traits are associated with resistance to fire, thus fire-resistant species may give rise to more fire-resistant landscapes. However, up-scaling from plant traits to landscape- and regional-scale fire effects remains a challenge. Objectives: We test two hypotheses: (1) forests composed of fire-resistant species experience lower fire severity than forests composed of less fire-resistant species; and (2) wildfires affecting forests with greater fire resistance experience smaller patches of high-severity fire. Methods: We used a predictive map of existing forest types (major tree species dominating forest composition) and a trait-based map of fire resistance. We examined large-scale spatial patterns of fire severity derived from Landsat imagery in 611 wildfires across the range of western larch in the Inland Northwest USA (1985–2014). We then applied structural equation modeling to study complex relationships between fire resistance and high-severity fire in each wildfire. Results: Forest types dominated by fire-resister species (e.g., ponderosa pine) experienced lower fire severity than forest types dominated by non-resister species such as lodgepole pine (fire-embracer) and subalpine fir (fire-avoider). We found a strong negative correlation between the fire resistance index and average values of the relative differenced normalized burn ratio, as well as an indirect relationship between fire resistance and high-severity patch size. Conclusions: The large-scale differences in fire severity among forest types generally reflect the degree of fire resistance that fire-related traits confer to individual trees species, providing evidence that incorporating plant traits has the potential to assist in assessing fire resistance at large spatial scales. [ABSTRACT FROM AUTHOR]

The focus of research and conservation in tropical regions is mainly devoted to forest ecosystems, usually neglecting the processes underlying widespread, more open biomes, like savannas. Here we test a wide range of sampled woodland sites across the South American savanna for the direct and indirect effects of habitat loss and vegetation density on the diversity of small-mammal species. We quantify the direction and magnitude of the effects of habitat amount (habitat loss), vegetation density (tree or foliage density), and patch size (species-area effect) on species composition and richness. We also test whether the relative effect sizes of landscape and patch-related metrics predict a persistence gradient from habitat specialist to generalist species across 54 sites. We used structural equation models (SEM) to test our predictions. After 22,032 trap-nights considering all sampled sites and 20 small-mammal species identified, the structural equation model explained 23.5% of the variance in the richness of small-mammal species. Overall, we found that landscape-level metrics were more important in explaining species richness, with a secondary role of patch-level metrics such as vegetation density. The direct effect of local landscape was significant for explaining species richness variation, but a strong positive association between regional and local landscapes was also present. Furthermore, considering the direct and indirect paths, SEM explained 46.2% of the species composition gradient. In contrast to species richness, we recorded that the combined landscape-level and patch-level metrics are crucial to determining small-mammal species composition at savanna patches. The small mammals from the South American woodland savanna exhibit clear ecological gradients on their species composition and richness, driven by habitat specialist (e.g., Thrichomys fosteri, Monodelphis domestica, and Thylamys macrurus) and generalist (e.g., Didelphis albiventris, Rhipidomys macrurus, and Calomys callosus) species’ responses to habitat amount and/or vegetation density, as seen in dense-forest Neotropical biomes.

A fundamental question in ecology is to understand how a species is distributed in a landscape. In terrestrial landscapes, the size and isolation of habitat patches, and matrix properties, are thought to drive population density patterns. Yet, given the same set of landscape features, why do species from a single taxon vary so widely in their density patterns? A primary hypothesis for such variation, proposed by community-level studies, is that key ecological characteristics of species influence how they respond to landscape features. However, robust tests of this hypothesis, which require measurements of populations of multiple species in an assemblage, are still scarce. We investigated the ability of ecological specialisation and the interaction of species with the matrix (matrix resistance) to predict population responses of butterfly species to patch size and connectivity in naturally heterogeneous tropical forest–grassland complexes. We surveyed 56 habitat patches in a 65 sq. km area by laying 276 transects, along which the identity and abundances of butterfly species were recorded. We also used transects that cut across two habitats to estimate matrix resistance. We find that habitat specialisation predicted the strength of area-density and isolation-density relationships. Matrix resistance also predicted variation in area-density relationships, highlighting the importance of species interactions with the matrix. Specialists showed higher matrix resistance and stronger area and isolation effects than did generalists. Our findings suggest that investigating how traits related to ecological specialisation and matrix resistance affect demographic parameters can contribute towards understanding mechanisms underlying species distributions in heterogeneous landscapes. [ABSTRACT FROM AUTHOR]

Invasive alien species are regarded as the second greatest threat to biodiversity globally. Yet, at a local scale their effects may vary, underlying the requirement for more local-scale studies across taxa and settings. Here we consider the effects of an alien invasive tree (Acacia dealbata, 5–8 m tall) on avifaunal numbers, richness and diversity in A. dealbata patches of three sizes relative to adjacent montane grasslands. Analysis of historical aerial photographs showed that A. dealbata first occurred in the area in the late 1930s/early 1940s and has continued to spread, despite some efforts by the landowner to keep it in check. It now covers approximately 11% of the site. This has provided habitat for a number of bird species more characteristic of wooded vegetation types. The number, richness and diversity of birds were greater in A. dealbata patches than the adjacent grasslands of equivalent size. These measures increased with increasing patch size, but more rapidly for A. dealbata patches than grassland ones. Only six of the 48 species of birds recorded were common between the two vegetation types. The most common feeding guild in the A. dealbata patches was insectivores, whereas in the grasslands it was omnivores. Although the invasion of A. dealbata has added to the habitat diversity of the area, thereby facilitating increased avifaunal diversity, if it continues to spread, then the populations and perhaps richness of grassland birds are likely to be negatively affected. [ABSTRACT FROM AUTHOR]

Forest disturbances have been altering the ecological properties of ecosystems; meanwhile, disturbance events of varying sizes create different structures and functions for a forest landscape. Therefore, size and frequency are important attributes of disturbances, and their relationship should be studied. We present a hierarchical method through the modeling of the overall trend of the size–frequency distribution and the characterization of the non-constant variances of disturbance sizes at each frequency level. This method was demonstrated to accurately model the sizes as well as the corresponding frequencies; thus, the total disturbed area and number of disturbance patches were both accurately estimated. By applying the method to 13 provinces in China, consistent patterns were revealed by the modeling results and remote-sensing-based product, showing that between 2000 and 2005, forests in most provinces were dominated by moderate disturbances (10 ha < size < 100 ha). Southeastern provinces contain the largest proportion of small disturbances (size < 10 ha), whereas most of the very large disturbances (size > 1000 ha) occurred in the northeastern and northwestern provinces. This study concludes that the proposed method can improve the representation of the size–frequency distribution of forest disturbances.

Urbanization can have profound consequences for mammalian biodiversity and is thought to contribute to patterns of species richness and community composition. Large cities can be particularly challenging environments for mammals because these habitats are often impacted by anthropogenic perturbations, including high human population density, fragmented habitats, and extensive human development. In this study, we investigated mammalian species richness, Shannon–Wiener diversity, and evenness in the most densely populated region in the United States: the New York metropolitan area. Specifically, we deployed camera traps from 2015 to 2019 to investigate six drivers of mammalian diversity across 31 greenspaces: (1) human population density, (2) patch size, (3) habitat type, (4) surrounding land cover, (5) geographical barriers to dispersal, and (6) habitat heterogeneity. We found that mammal community composition is largely influenced by a multitude of anthropogenic factors. Specifically, mammal species richness was higher in greenspaces with larger patch sizes and lower in greenspaces surrounded by more development. Moreover, Shannon–Wiener diversity and evenness were higher in urban natural landscapes than human-altered landscapes. In a subset of data that only included carnivores, we found that carnivore Shannon–Wiener diversity was higher in urban natural habitats and in sites with lower human population densities. Finally, we found that geographical barriers to dispersal contributed to both patterns of mammalian diversity and patterns of carnivore diversity: mammal taxa richness, Shannon–Wiener diversity, and evenness were all significantly higher on the continent (Bronx/Westchester) than on Long Island. These results suggest that preserving urban greenspaces is important for maintaining both mammalian and carnivore biodiversity and that management of mammals in cities should concentrate on maintaining large, connected, natural greenspaces.

Quantifying prey characteristics is important for understanding the foraging behaviour of predators, which ultimately influence the structure and function of entire ecosystems. However, information available on prey is often at magnitudes which cannot be used to infer the fine-scale behaviour of predators, especially so in marine environments where direct observation of predator–prey interactions is rarely possible. In the present study, animal-borne video data loggers were used to determine the influence of prey type and patch density on the foraging behaviour of the little penguin (Eudyptula minor), an important predator in southeastern Australia. We found that numerical density positively influenced time spent foraging at a patch. However, when accounting for calorific value in density estimates, individuals spent longer at dense patches of low-quality prey. This may reflect a trade-off between capture effort and calorific gain as lower quality prey were captured at higher rates. During the breeding season, foraging trip distance and duration is constrained by the need to return to the colony each day to feed offspring. The results of the study suggest that, under these spatio-temporal constraints, little penguins maximize foraging performance by concentrating efforts at larger quantities of prey, irrespective of their calorific quality.

Context: Area sensitivity, a behaviour whereby smaller patches of habitat are avoided, is of significant conservation concern for North American grassland birds. However, it is unclear whether area sensitivity is caused by patch size per se, or whether it results from factors such as landscape openness, which often covaries with patch size. Objectives: We aimed to determine which characteristics of a grassland patch or the landscape surrounding it most influence habitat use by tall-grass prairie birds. Methods: Using point-count data collected from 20 tall-grass prairie patches in Southern Manitoba, Canada, we determined which spatial extent and landscape characteristics contributed most to area sensitivity for five species of grassland passerines and grassland bird species richness. We assessed the relative importance of patch size, landscape composition within spatial extents ranging up to 8000 m from sampling locations, and edge proximity then compared the importance of landscape characteristics to that of local habitat structure. Results: The proportion of open landscape dominated by low-stature plants had a positive effect on species richness and the relative abundances of all focal species, and was generally more important than patch size, habitat amount, edge proximity, or local habitat structure. Conclusions: These results suggest that landscape openness, not patch size or habitat amount, drives area sensitivity of grassland birds. Grassland patches embedded in open landscapes are less susceptible to area sensitivity and may be of high conservation value for grassland birds, even when small. [ABSTRACT FROM AUTHOR]

Aim: Wildfires increasingly create large high‐severity patches with interior areas far from less disturbed habitats. We evaluated how these trends impact bird communities by investigating the effect of internal distance from lower‐severity areas, high‐severity patch size, and years since fire on avian alpha and beta diversity. Location: Sierra Nevada, California, USA. Methods: Bird occurrence data were collected during 2009–2017 within high‐severity patches of 27 wildfires representing 1–30 years since disturbance. A two‐step multispecies occupancy method was used to account for imperfect detection of 94 species and estimate effects of patch characteristics on community richness and dissimilarity. Results: Community richness decreased with distance from patch edge and with patch size. Richness increased with years since fire, but this pattern was dependent on distance from edge with higher peak richness (23 species) near edges than interiors (18 species). Community dissimilarity was not associated with distance, indicating that large high‐severity patch interiors contain subsets of, rather than complements to, edge communities. Dissimilarity peaked later with increasing patch size. Guild richness of tree and primary cavity nesters was negatively associated with distance and patch size. Richness of ground and shrub nesters was insensitive to distance, while shrub nester richness increased somewhat with patch size. Due to declines among other species, ground and shrub nesters made up a greater percentage of the avian community within the interiors of large high‐severity patches. Main conclusions: As fire activity increases due to accumulating forest fuels and accelerating climate change, high‐severity patches and their resulting early‐seral habitats are becoming more extensive with less edge and more interior area. Such changes are likely to decrease avian diversity locally and shift community composition away from forest‐associated species. Management actions that promote the full range of fire effects but limit high‐severity patch size may best conserve bird diversity within fire‐adapted ecosystems. [ABSTRACT FROM AUTHOR]

Seed dispersal by frugivorous animals is important for plant mobility, regeneration and persistence. Human‐caused landscape change is thought to disrupt seed dispersal, but evidence is scarce. We performed a comprehensive meta‐analysis on the effects of habitat spatial pattern on frugivory and seed dispersal. We found 233 effects from 71 studies. At a patch or local scale, altered habitat spatial pattern was measured as declining patch size, increasing patch isolation or habitat edge (versus interior). At a landscape scale it was measured as declining amount of habitat, increasing mean patch isolation, increasing number of patches or increasing habitat edge in the landscape. We found overall negative effects of altered habitat spatial pattern on: 1) the quantity of frugivory or seed dispersal, 2) the number of species involved in a plant–frugivore interaction and 3) seed dispersal distance. Moderator variable analysis was only possible for the first of these. It revealed negative responses of the quantity of frugivory or seed dispersal to habitat loss at both the local scale (declining patch size), and the landscape scale (declining habitat amount), but little evidence for a response to habitat edge at either scale. In addition, altered habitat spatial pattern reduced the quantity of frugivory or seed dispersal more strongly in temperate than tropical areas. Finally, the few‐recorded effects of landscape‐scale fragmentation per se (increasing patch density or edge density) on the quantity of frugivory or seed dispersal were mixed and weak. Our meta‐analysis reinforces the notion that habitat loss is a major threat to frugivory and seed dispersal by animals, and reveals an insufficiency of studies of the effects of habitat fragmentation per se. Thus, based on the current literature, we conclude that maintaining and increasing habitat amount is vital for maintaining seed dispersal by frugivorous animals. [ABSTRACT FROM AUTHOR]

Refueling performance is the primary currency of a successful migration as birds must maintain energy stores to achieve an optimal travel schedule. Migrating birds can anticipate heightened energy demand, not to mention increased uncertainty that energy demands will be satisfied, especially within an urbanizing landscape following long-distance flights. We tested the expectation that refueling performance of songbirds is reduced as densities increase at stopover sites in an urbanizing coastline of the Gulf of Mexico. We measured the density of migrating birds, their refueling performance, and arthropod abundance in two large tracts of contiguous forest paired with two small isolated patches embedded within residential settings throughout spring migration over the course of 2 years. Refueling performance declined with increasing migrant densities, even though the overall daily densities of birds stopping in these landscapes were relatively low and arthropod densities were low throughout. Habitat patch size alone did not account for differences in refueling performance, but smaller habitat patches more often concentrated migrants in higher densities where they experienced reduced refueling performance. We found support for density-dependent refueling performance during spring migration through a region where overall passage and stopover densities are low; suggesting that larger contiguous forest tracks within urban landscapes provide higher quality habitat for refueling and that effect is likely even more pronounced in landscapes within higher density migratory corridors. The nutritional challenges encountered during migration influence the overall pace of migration and changes in access to food resources due to increasing urbanization may ultimately impact optimal travel schedules.

Urbanization is the land-use process that most significantly impacts flora and fauna. We conducted a multiple city comparison of two taxa to assess whether richness patterns are similar across cities and taxa. This study aimed to examine the effects socioecological factors, namely open area size, socioeconomic status and the built-up cover, on species richness and composition of plants and butterflies in five adjacent Mediterranean cities in Israel's coastal plain. Vegetation surveys were conducted in 170 open area sites in various urban settings. In 34 of them, the presence of butterfly species was also recorded. Mixed-effect generalized linear models were used to examine the site's characteristics effect on the species richness. The identity of each city was included as a random effect in the models. Results indicated that overall plant species richness increased with patch size, whereas butterfly richness was not associated with this factor. Plant and butterfly species richness in all categories decreased with the increase in building cover, except for endemic plant species. The results demonstrate the complex contribution of urban open area patches to the biodiversity of different taxa, being conditional on their size, surrounding built-up area and socioeconomic values. [ABSTRACT FROM AUTHOR]

Context: It is estimated that over one billion milkweed stems need to be restored to sustain the eastern North American migratory population of monarch butterflies; where and in what context the stems should be placed on the landscape is key to addressing habitat deficits. Objectives: We assessed how the amount of appropriate habitat surrounding a particular patch of monarch habitat affects monarch presence and reproduction. To ensure that habitat restoration efforts are targeted towards areas that maximize monarch population growth, it is important to understand the effects of landscape heterogeneity on monarch occurrence in habitat patches (i.e. grasslands with milkweeds) across the landscape. Methods: Over two summers (2018–2019), we surveyed monarch adults, larvae, and eggs at sixty grassland sites in Wisconsin that varied in patch size and landscape context (proportion grassland, forest edge density, and road density). We also estimated milkweed density and floral richness to characterize local patch quality. Results: Adult monarch abundance was highest at patches with the lowest proportion of surrounding grassland and lowest road density, and was heavily influenced by patch quality variables. Egg and larva density in a patch increased with milkweed density and floral richness within a patch. Patch size was unrelated to monarch abundance. Conclusions: These results suggest that optimal sites for monarch habitat restoration are within landscapes which contain little habitat and that high milkweed density and floral richness and abundance should be conservation goals. [ABSTRACT FROM AUTHOR]

This study evaluated the relationship of biodiversity with the patch size of village common forests (VCF) by analyzing floral biodiversity based on data from 25 selected VCFs in the Chittagong Hill Tracts (CHT), Bangladesh. The study took 225 quadratic plots by taking nine 10 m × 10 m plots from each VCF—three from each of base, mid, and top hill slopes. The coefficient of similarity (CS) among VCFs and forest community features including species richness, basal area, and popular diversity indices were calculated. Generalized linear model (GLM) assessed the bearings of patch size, slope, and elevation on stand parameters. In all, the study recorded the occurrence of 165 plant species from 52 families. Euphorbiaceae was the dominant family with 18 species. Seven least concerned and four threatened species as per the IUCN red data list of Bangladesh were found in VCFs. Vitex peduncularis had the highest importance value index (IVI) score followed by Lannea coromandelica and Ficus hispida. The mean CS of the VCFs was 0.54. The VCFs were rich in biodiversity, as indicated by observed species richness (644 species/ha), stem density (7111 plants/ha), basal area (65.56 m2/ha). Scores in biodiversity indices, viz. Shannon–Wiener diversity index (2.59), Simpson index (0.90), and evenness index (0.61), also concluded rich but heterogeneous biodiversity among VCFs comparable to other natural forests in the country. The GLM revealed the absence of significant (p ≤ 0.05) bearings of patch size, elevation, or slope on community parameters. The insensitivity of forest community parameters to patch size and elevation indicated the value of conserving VCFs irrespective of sizes and locations. [ABSTRACT FROM AUTHOR]

Patch size is one of the most important factors affecting the distribution and abundance of species, and recent research has shown that patch size is an important niche dimension affecting community structure in aquatic insects. Building on this result, we examined the impact of patch size in conjunction with presence of larval anurans on colonization by aquatic insects. Hyla chrysoscelis (Cope's gray treefrog) larvae are abundant and early colonists in fishless lentic habitats, and these larvae can fill multiple ecological roles. By establishing larvae in mesocosms prior to colonization, we were able to assess whether H. chrysoscelis larvae have priority effects on aquatic insect assemblages. We conducted a series of three experiments in naturally colonized experimental landscapes to test whether (1) H. chrysoscelis larval density affects insect colonization, (2) variation in patch size affects insect colonization, and (3) the presence and larval density of H. chrysoscelis shift colonization of insects between patches of different size. Larval density independently had almost no effect on colonization, while patch size had species‐specific effects consistent with prior work. When larvae and patch size were tested in conjunction, patch size had numerous, often strong, species‐specific effects on colonization; larval density had effects largely limited to the assemblages of colonizing beetles and water bugs, with few effects on individual species. Higher larval densities in large mesocosms shifted some insect colonization to smaller patches, resulting in higher beta diversity among small patches in proximity to high density large mesocosms. This indicates establishing H. chrysoscelis larvae prior to insect colonization can likely create priority effects that slightly shape insect communities. Our results support the importance of patch size in studying species abundances and distributions and also indicate that colonization order plays an important role in determining the communities found within habitat patches. [ABSTRACT FROM AUTHOR]

Context: In central Queensland, Australia, the development of a coal-seam gas (CSG) industry is creating additional fragmentation of landscapes consisting of woodland and open forest that are already highly fragmented. Aims: To assess the response to fragmentation of Strophurus taenicauda (golden-tailed gecko). The species is 'near threatened' in Queensland. Methods: Occurrence and abundance were examined across three categories of patch size – small (≤10 ha), medium (10–100 ha) and large (≥100 ha) – across three geographic areas of the species' range. Minimal impact (i.e. sighting only) active searches for geckos were conducted at night. A minimum of three replicate sites of each patch size category was surveyed in each of the three geographic areas. Eleven additional patches (each <4 ha and located in the southern geographic area) were surveyed to investigate how size and spatial isolation of small patches affected occurrence and abundance of S. taenicauda. At all sites a standardised set of 22 habitat variables was collected, and the presence of other species of arboreal gecko was recorded. Key results: The species was located across patches of all sizes, including those as small as 1.11 ha. It was also located opportunistically in the matrix among patches and occurred in isolated trees within an urban area. The abundance of another commonly occurring arboreal gecko, Gehyra dubia (dubious dtella), was negatively correlated with S. taenicauda abundance in small patches. The most important habitat variable for S. taenicauda was average basal area of trees. As this increased, especially above 5.7 m2 ha−1, it was more likely to be present. When considering only the small patches, the main factors influencing presence and abundance of S. taenicauda were the average basal area of Callitris glaucophylla (white cypress) and grazing (negligible or absent). Conclusions: Strophurus taenicauda is a species that is tolerant of disturbance and can persist in fragmented habitat, provided the fragments have adequate cover of white cypress. Implications: The species appears to be resilient to the current level of CSG development within its geographic range. Additional fragmentation of already fragmented landscapes has emerged as a conservation issue in developed countries experiencing energy development projects that focus on extraction of unconventional gas. To address this issue we assessed the response to additional habitat fragmentation of Strophurus taenicauda (golden-tailed gecko) in the Brigalow Belt of Queensland, Australia, an area heavily fragmented by over 150 years of agricultural development. We sought to understand how fragmentation influences the occurrence and abundance of S. taenicauda and to use this information to predict how it may be impacted by the development of a coal-seam gas industry. Photograph by Eric Vanderduys. [ABSTRACT FROM AUTHOR]

Soil heterogeneity significantly affects plant dynamics such as plant growth and biomass. Most studies developed soil heterogeneity in two dimensions, i.e. either horizontally or vertically. However, soil heterogeneity in natural ecosystems varies both horizontally and vertically, i.e. in three dimensions. Previous studies on plant biomass and biomass allocation rarely considered the joint effects of soil heterogeneity and species composition. Thus, to investigate such joint effects on plant biomass and biomass allocation, a controlled experiment was conducted, where three levels of soil heterogeneity and seven types of species compositions were applied. Such soil heterogeneity was developed by filling nutrient-rich and nutrient-poor substrates in an alternative pattern in pots with different patch sizes (small, medium or large), and species compositions was achieved by applying three plant species (i.e. Festuca elata , Bromus inermis , Elymus breviaristatus) in all possible combinations (growing either in monoculture or in mixtures). Results showed that patch size significantly impacted plant biomass and biomass allocation, which differed among plant species. Specially, at the pot scale, with increasing patch size, shoot biomass decreased, while root biomass and R:S ratio increased, and total biomass tended to show a unimodal pattern, where the medium patch supported higher total biomass. Moreover, at the substrate scale, more shoot biomass and total biomass were found in nutrient-rich substrate. Furthermore, at the community scale, two of the three target plant species growing in monoculture had more shoot biomass than those growing together with other species. Thus, our results indicate soil heterogeneity significantly affected plant biomass and biomass allocation, which differ among plant species, though more research is needed on the generalization on biomass allocation. We propose that soil heterogeneity should be considered more explicitly in studies with more species in long-term experiments. [ABSTRACT FROM AUTHOR]

Abstract Habitat selection theory suggests that when choosing breeding sites, animals should choose the best available habitat; however, studies show that individuals fail to choose habitats that maximize their fitness especially in drastically altered landscapes. Many studies have focused on selection at single scales, often using a single measure of fitness. However, links between habitat selection and fitness may vary depending on the spatial scale and measure of fitness, especially in situations where agricultural land use has altered the surrounding landscape. We examined multiscale habitat selection and fitness measures of the Bell's Vireo (Vireo bellii) and Willow Flycatcher (Empidonax traillii) using data collected in agriculturally fragmented landscapes. We found evidence for selection of nest sites with dense understory, larger patches, and increasing restored habitat cover and decreasing forest cover in the surrounding landscape. For both focal species, selection for dense understory significantly increased nest survival; however, there appeared to be no concurrent benefit for fledgling production. Selection for broader scale features positively influenced nest survival for the Willow Flycatcher with no concurrent benefit for fledgling production. The observed mismatches may be due to anthropogenic habitat fragmentation at broader scales or may represent reproductive trade‐offs for a fitness benefit not measured in this study. Fine‐scale habitat selection decisions by our focal species appear to match fitness outcomes, whereas habitat selection at broader scales only provided fitness benefits for the Willow Flycatcher. Though providing no fledgling production benefit, when combined with suitably dense nesting habitat, larger patches in landscapes with greater amounts of restored habitat cover for Bell's Vireo and lower amounts of forest cover for Willow Flycatcher will produce more fledglings per unit area than smaller patches in landscapes with less restored habitat and more forest cover, respectively, which could help inform conservation decisions for these at‐risk species.

Background: The hermit beetle (Osmoderma barnabita) is an internationally protected specialist of tree hollows considered a relic of primeval forests. The backbone of its distribution in eastern Czechia, however, is a system of pollard willows in intensively farmed lowlands. Pollarding, a traditional agroforestry practice inducing formation of tree hollows, was partly abandoned in the area during the twentieth century. Aim: To assess the state of the system of pollard willows and to investigate parameters of pollards and their stands which affect the beetle's presence. Methods: We inventoried pollard trees and beetle distribution across ca 2000 km2 of lowlands along the Dyje, Morava and Odra rivers and their tributaries in eastern Czechia and westernmost Slovakia. Results: We found 10 441 pollard willows in 324 stands: most stands contained trees of large diameters and poor health; young trees were rare. Probability of O. barnabita presence increased with number of trees in stand, decreased with distance to the nearest occupied stand, and was further affected by the health state of trees. Discussion: Our results show that high hollow density in pollards allows for the existence of specialized, dispersal limited forest organisms in virtually deforested landscapes. They suggest stands should contain at least 200–300 pollard willows to sustain the beetle population. Although the beetle is still widespread over the study area, the existing populations are isolated and subjected to extinction debt. Implications for insect conservation: Large-scale restoration of pollarding practice, planting and pollarding of numerous young trees, and increasing connectivity is vital to facilitate the survival of this hermit beetle population but also support other hollow associated organisms. [ABSTRACT FROM AUTHOR]