Island Ecosystems Research Articles

Unveiling the nexus and promoting integration of diverse factors: Prospects of big data-driven artificial intelligence technology in achieving carbon neutrality in Chongming District

Climate change is one of the most pressing challenges facing the world today. The large amount of greenhouse gas emissions produced by human activities, especially the emission of carbon dioxide, is an important driving factor behind climate issues. Under the background of China’s “3060” decarbonization goal”, Chongming District in Shanghai is actively promoting the construction of a world-class ecological island and is committed to creating a carbon–neutral demonstration zone with global influence. However, Chongming District faces challenges as the mechanism of carbon-neutrality transition path remains unclear. The data related to evaluating carbon neutrality status are heterogeneous from multiple sources. It is difficult to effectively implement relevant evaluation and response measures, impeding the progress of its low-carbon transformation. In response to the aforementioned challenges, this paper will propose and discuss the potential methods based on the new generation of information technology, represented by big data and artificial intelligence. These technologies aim to facilitate the integration of diverse factors, including carbon, and explore the nexus among them, thus exploring pathways for low-carbon transformation, and ultimately achieving decarbonization goal in Chongming District. Hopefully, the research conducted in this paper will contribute to the efforts of China and the global community in addressing carbon-related challenges and advancing towards a more sustainable and low-carbon future.

Assessment of macrobenthic communities of rocky intertidal zone from Zhejiang offshore islands with AZTI marine biotic index

The structure of macrobenthic communities in island intertidal zones serves as an important indicator for assessing the health status of ecosystems. In recent years, the unregulated and extensive development and utilization of island resources in China, coupled with the continuous deterioration of the ecological environment in the surrounding marine areas of islands, have significantly impacted the health and stability of island ecosystems. Four investigations during spring (2018, 2021) and autumn (2017, 2020) of the Niushan Island intertidal zones and surrounding waters, located off the coast of Taizhou, Zhejiang, were conducted in this study. The purpose was to explore the external factors influencing the structure of intertidal macrobenthic communities and to assess the ecological status of the island. There was a clear vertical zonation observed in the distribution of the macrobenthic communities. During this survey, the eutrophication index improved, and the temperature, salinity, and suspended particulate matter exhibited seasonal fluctuations. Dissolved inorganic phosphorus and nitrate were the environmental factors that required special attention in coastal ecological monitoring, which significantly affected the distribution of the macrobenthic communities and was strongly correlated with the biotic indices and different ecological group biomasses. Most of the islands were classified as having a moderate status based on the Shannon-Wiener diversity index (H'). The AZTI Biotic Index (AMBI) and Multivariate AMBI (MAMBI) indicated that almost all islands were in good status, and the evaluation results demonstrated that the AMBI and MAMBI tended to overestimate the ecological status of the rocky intertidal zone. There was a significant correlation between the MAMBI and several traditional biological indices, suggesting that the MAMBI could be introduced as an evaluation indicator for the ecological status of rocky reefs. Nevertheless, it is important to consider the boundaries of different assessment levels.

Ecological non-equilibrium and biological conservation

How to establish efficient conservation actions and policies for the long-term persistence of ecological systems remains a challenge. Conservation biology was born as a discipline of crisis, targeting the recovery of altered ecosystems under the paradigms of equilibrium and ecological stability. However, we argue that the concepts of ecological equilibrium and balance still hinder wildlife managers from optimizing proper decision-making and correctly prioritizing conservation actions. This is still the case, despite the prevailing paradigm has recently shifted to a more realistic view of non-equilibrium dynamics in ecosystems, even in the absence of anthropogenic impacts. The challenge for managers and policymakers is now even greater. First, because non-equilibrium is the basis for the Darwinian adaptive response of ecosystems, and hence maintaining variance, rather than decreasing it, should be the target of conservation. Secondly, ecosystems show non-linear responses (e.g. transients and critical transitions), which hamper diagnosis and prediction. Even though we are unable to suggest solutions to this conundrum, we warn here about potential biases when conserving non-equilibrium ecosystems. We suggest that insights from island ecology and medical science may be helpful when dealing with non-equilibrium in applied conservation. Incorporating the advances of the discipline of complex systems into the conceptual framework of management and policymaking may also contribute to improving the prioritization of actions, especially regarding some agents of global change. Finally, we advocate for the strengthening of the feedback between ecologists (both theoretical and empirical) and conservation practitioners to improve our knowledge on how ecosystems respond to perturbations.

Host phylogeny shapes viral transmission networks in an island ecosystem

Virus transmission between host species underpins disease emergence. Both host phylogenetic relatedness and aspects of their ecology, such as species interactions and predator–prey relationships, may govern rates and patterns of cross-species virus transmission and hence zoonotic risk. To address the impact of host phylogeny and ecology on virus diversity and evolution, we characterized the virome structure of a relatively isolated island ecological community in Fiordland, New Zealand, that are linked through a food web. We show that phylogenetic barriers that inhibited cross-species virus transmission occurred at the level of host phyla (between the Chordata, Arthropoda and Streptophyta) as well as at lower taxonomic levels. By contrast, host ecology, manifest as predator–prey interactions and diet, had a smaller influence on virome composition, especially at higher taxonomic levels. The virus–host community comprised a ‘small world’ network, in which hosts with a high diversity of viruses were more likely to acquire new viruses, and generalist viruses that infect multiple hosts were more likely to infect additional species compared to host specialist viruses. Such a highly connected ecological community increases the likelihood of cross-species virus transmission, particularly among closely related species, and suggests that host generalist viruses present the greatest risk of disease emergence.

Dendroecological analysis of the remote endemic Nothomyrcia fernandeziana forests of Robinson Crusoe Island in the Southeast Pacific

Juan Fernández Archipelago National Park is located in the Southeast Pacific Ocean ∼670 km off the coast of Chile. Composed by three islands, encompasses an ecosystem with 208 native plant species of which 64% are endemic. Robinson Crusoe Island (RCI) is the largest and the only with a permanent human population. Among the tree species of RCI, Nothomyrcia fernandeziana is the most abundant and dominant forming part of this fragile forest ecosystem. Despite this, there is very little information regarding its autoecology and conservation. Therefore, the objective of this work was to determine the radial growth patterns of N. fernandeziana and its longevity using dendrochronological methods. For this purpose, cross sections of trees blown down by wind were collected in conjunction with park rangers from five different sites and analyzed using tree-ring methods. Our results confirm that N. fernandeziana is a shade-tolerant species capable of maintaining extremely low initial growth rates under the canopy for several decades. Individual growth series were found to respond rapidly to changes in environmental conditions, revealed by abrupt positive and negative changes in their annual growth. Our data indicate a longevity of up to 450 years, with one N. fernandeziana individual established in the mid XVII century before the arrival of humans to the pristine island ecosystem. The results of this study are essential to strengthen RCI conservation plans considering restoration actions based on the autoecology of this rare endemic tree species, and the control of exotic invasive species that presently threatens the RCI forests ecosystems.

Ecological challenges on small tourist islands: A case from Chinese rural island

AbstractThe expansion of the global tourism market has accelerated the development of small tourist islands. The rapid growth of tourist scale and activity intensity poses a potential threat to the fragile ecosystems of small islands. This article focuses on the ecological stresses small tourism islands face in their development. Compared with similar studies, we found a more flexible way to measure ecological stress of current activities. We show a framework for ecological stress assessment on small rural islands and illustrate it with Weizhou Island, China. It reveals a new approach to combining ecological footprint, geographic data, and visitor activity data. This combination enables a spatial linkage between biophysical and social surveys. To verify the validity of the assessment framework, we assessed the spatial distribution of ecosystem loss on the island using habitat quality. A multi‐scale geographically weighted model describes the spatial correlation between ecological stress and habitat quality. Real‐world application cases were used to test the usability and practical use of the policy assessment framework. We provide methodological and application‐based contributions to support the sustainable development of small tourist islands. Overall, the assessment framework offers a reliable solution for systematically collecting, analyzing, and reporting ecological stresses faced by small tourist islands.

Pathogenic Leptospira are widespread in the urban wildlife of southern California

Leptospirosis, the most widespread zoonotic disease in the world, is broadly understudied in multi-host wildlife systems. Knowledge gaps regarding Leptospira circulation in wildlife, particularly in densely populated areas, contribute to frequent misdiagnoses in humans and domestic animals. We assessed Leptospira prevalence levels and risk factors in five target wildlife species across the greater Los Angeles region: striped skunks (Mephitis mephitis), raccoons (Procyon lotor), coyotes (Canis latrans), Virginia opossums (Didelphis virginiana), and fox squirrels (Sciurus niger). We sampled more than 960 individual animals, including over 700 from target species in the greater Los Angeles region, and an additional 266 sampled opportunistically from other California regions and species. In the five target species seroprevalences ranged from 5 to 60%, and infection prevalences ranged from 0.8 to 15.2% in all except fox squirrels (0%). Leptospira phylogenomics and patterns of serologic reactivity suggest that mainland terrestrial wildlife, particularly mesocarnivores, could be the source of repeated observed introductions of Leptospira into local marine and island ecosystems. Overall, we found evidence of widespread Leptospira exposure in wildlife across Los Angeles and surrounding regions. This indicates exposure risk for humans and domestic animals and highlights that this pathogen can circulate endemically in many wildlife species even in densely populated urban areas.

An empirical study on relationship between island ecological environment and socio-economic development from perspective of environmental Kuznets curve (EKC)

Constrained by the limitations of its natural environment, the island ecosystem remains susceptible to the influence of human activities. Achieving a state of equilibrium and sustainability between the ecological milieu and regional economic growth becomes a paramount goal. To this overarching aim, the author embarked on an endeavor to assess the ecological landscape of Hainan Island utilizing the Remote Sensing Ecological Index (RSEI) model. This appraisal was further coupled with an empirical exploration of its interplay with socioeconomic progress through a panel regression framework. The outcomes borne of this meticulous inquiry unveil a compelling dynamic: the nexus between the ecological environment and socioeconomic advancement assumes the form of a “positive N-shaped” curve. This signifies that the ecological milieu prospers in tandem with the ascent of GDP per capita up until the emergence of the first inflection point (corresponding to a GDP per capita of 18,796.01 yuan). Following this juncture, the ecological conditions start to deteriorate, only to experience a revival leading to the second inflection point (marked at a GDP per capita of 70,586.91 yuan). Moreover, it's worth noting that the variables under scrutiny in this study, with particular emphasis on the industrial structure, wield a discernible influence on the Environmental Kuznets Curve (EKC). In light of these findings, it is imperative that environmental regulatory authorities implement judicious strategies aimed at harmonizing economic advancement with ecological preservation. By doing so, a harmonious balance between developmental gains and environmental stability can be achieved.

Fracturing, Flux & Fragility: Mapping Ecological Islands & Edges

Fracturing, Flux & Fragility: Mapping Ecological Islands & Edges

Patterns in sightings of ocean sunfishes (Molidae) in the greater Dyer Island ecosystem, Western Cape, South Africa

This study aims to describe the distribution of ocean sunfishes (family Molidae) in the greater Dyer Island ecosystem off the southwest coast of South Africa. Between 2014 and 2022, local whale watching vessels operating under Dyer Island Cruises conducted 3 227 trips which resulted in 274 trips with Molidae sightings, with a total of 300 individuals sighted. Molidae sightings showed a significant correlation to sea surface temperature and a strong seasonal pattern. Sightings in the greater Dyer Island area increased significantly after 2016, suggesting a correlation with the decline of white shark Carcharodon carcharias sightings, with further increases in 2021. This suggests that the greater Dyer Island ecosystem has become a more favoured habitat for species of Molidae.

Soil phosphorous is the primary factor determining species-specific plant growth depending on soil acidity in island ecosystems with severe erosion

Disturbances caused by invasive ungulates alter soil environments markedly and can prevent ecosystem recovery even after eradication of the ungulates. On oceanic islands, overgrazing and trampling by feral goats has caused vegetation degradation and soil erosion, which can alter soil chemistry. To understand the effects of the changes on plant performance, we conducted a laboratory experiment to assess herbaceous species growth under various soil conditions with phosphorous, nutrients, and acidity. Subsoil was collected from Nakodo-jima in the northwest Pacific. Six herbaceous species dominating the island were grown in soils with three levels of added CaCO3 and P2O5 and two levels of added KNO3. After 4 weeks of growth, the total dry plant weight was significantly lower with no added P2O5, regardless of the addition of KNO3. Three species weighed more under P2O5 and KNO3 addition in high-pH soil, whereas the remaining three weighed less. Our results indicated that herbaceous species growth is limited primarily by phosphorous availability; the limitation is dependent on soil pH, and the trend of dependency differs among species. This implies that ecosystems with extreme disturbances cannot recover without improving the soil chemistry.

Colonization and coexistence of non‐native ants on a model Atlantic island

AbstractAimsColonization by non‐native ants represents one of the gravest potential threats to island ecosystems. It is necessary to identify general mechanisms by which non‐native species are able to colonize and persist in order to inform future prevention and management. We studied a model‐island assemblage of 17 non‐native ant species with aim of identifying the spatial source of introductions and assessing how such a diversity of species are able to coexist.LocationData were collected on Ascension Island: an ideal study system for its intermediate area, compact shape, spatial heterogeneity, lack of native ant species, and availability of non‐native ant records dating back to the 1800s.MethodsWe collected over 47,000 individual ants from 73 sites using a range of baited traps and survey techniques. We combined this novel data with past occurrence records in order to determine whether human settlements have historically been the source of ant introductions and to quantify the mean rate at which species have dispersed across the island. Analysis of standardized field data revealed the extent to which ants were partitioning ecological niche space via (1) habitat separation, (2) fine‐scale resource partitioning and (3) climatic heterogeneity.ResultsAnts were radiating at a linear rate of approximately 0.5 km2 per year from human settlements on this island, with the most widespread species having been introduced earliest. After accounting for incomplete colonization, we found no evidence to suggest habitat separation between species. Instead, we found significant niche separation through resource partitioning and weather‐dependent activity patterns.Main ConclusionsOur results indicate that non‐native ants can coexist in very close proximity and are therefore capable of existing at great diversity on even small islands. It is inevitable that ant colonization will continue without increased biosecurity measures, habitat restoration around settlements and conservation of native species populations.

Application of the Electromagnetic Method to the Spatial Distribution of Subsurface Saline and Fresh Water in the Coastal Mudflat Area of Jiangsu Province.

Interfacial zones straddling terrestrial and marine realms, colloquially known as mudflats, epitomize a dynamic nexus between these environments and are fundamental to the coastal ecosystem. The investigation of these regions is paramount for facilitating infrastructural developments including ports, wharfs, cross-sea bridges, and the strategic utilization of freshwater resources sequestered from mainland islands amid ongoing economic progress. Terrestrial realms conventionally employ electromagnetic techniques as efficacious modalities to delineate subterranean geological information, encompassing structural details and water-bearing strata. However, the peculiar topographic and geological nuances of mudflat regions pose substantial challenges for the efficacious application of electromagnetic methodologies. The present paper endeavors to address these challenges by suggesting innovative modifications to the existing instrumentation and evolving novel data acquisition techniques specifically tailored for electromagnetic exploration within mudflat environments. This paper delves into the electrical characteristics of water-bearing layers within mudflats, and ascertains details pertaining to the subterranean structure and the spatial distribution of fresh and saline water resources, through the holistic interpretation of a multitude of profiles.

Landscapes created by millennia of cultural land use in the Fleurieu Group of Islands, Tasmania—a knowledge baseline for current and future land management under changing climates

Aboriginal peoples have managed Australian landscapes for millennia; however, deep-time paleoecological evidence of the nature of landscape modification remains rare. The Fleurieu Group of islands in Bass Strait was one of the areas actively used by Aboriginal people in lutruwita (Tasmania), until forced dispossession of their lands due to European colonization occurred over 230 years ago, with subsequent land use including leaseholder pastoralism and nature conservation. There are emerging opportunities for greater input from Aboriginal people into land management of the islands now and into the future. This investigation of the long-term human–island ecosystem interactions in the area is aimed at providing a greater understanding of the impact of land-use changes on biodiversity and ecosystem change through time. Holocene multi-proxy paleoecological records from the islands show periods of low to high intensity land use, with the highest intensity periods occurring around 8500–6500 BP and the last 2000 years. Aboriginal land use in the past ∼2000 BP promoted a complex mosaic biodiverse landscape and provides a baseline for current and future land management on the islands and elsewhere in Tasmania.

The relationship between naturalized alien and native plant species: insights from oceanic islands of the south-east Pacific over the last 200 years

Aim: The relationship between native and naturalized alien species has been widely studied, particularly across large geographic scales. However, our knowledge of the spatial and temporal variations of their relationships is still limited, particularly for remote oceanic islands such as those of the south-east Pacific and across islands and archipelagos. In this study, we aim to assess the relationships between native and naturalized alien species by analyzing their current patterns of species-area relationships at different spatial scales, in addition to temporal variations in species richness, over the last 200 years.Area: One island (Rapa Nui) and two archipelagos (Juan Fernandez and Desventuradas Islands) comprising a total of 11 oceanic islands of the south-east Pacific (OISEP).Methods: We assembled the most comprehensive dataset of the vascular flora of the OISEP from currently available island flora checklists and updated with recent publications. Each plant species was classified as being native or naturalized alien. We examined temporal changes by estimating species richness, naturalization rates and naturalized-to-native ratios over time based on the first collection year of each naturalized alien species. Then, we determined the best shape of naturalized alien species richness accumulation over time by contrasting the fit of lineal, exponential, sigmoidal and Weibull regressions. Finally, we analyzed the relationships between native and naturalized species firstly at the inter-archipelagic scale by fitting island species-area relationship models and secondly at the island scale by performing ranged major axis regression analysis on residual values.Results: The OISEP flora dataset contained 674 species of which 282 were native and 392 were naturalized alien. Native island species-area relationships were similar to those of the naturalized alien species. Naturalized alien species richness increased notably through time with two clear peaks in 1950 and 2000. A Weibull regression and an exponential shape over time were the most appropriate fits for naturalized alien species richness accumulations at the inter-archipelagic scale, which further emphasizes the notable increase in naturalized alien species richness experienced in the timeframe examined here.Main conclusions: The relationship between naturalized alien species richness and native species richness was found to be independent of the geographic scale. The number of naturalized alien species clearly exceeded the number of native species on most islands but also for the whole OISEP. The accumulation of newly detected naturalized alien species does not show any sign of saturation and it is likely that new species will arrive in the future. Increased efforts on monitoring, prevention and biosecurity are needed to halt biological invasions on these unique island ecosystems.

The climbing flora of New Caledonia: a comprehensive checklist

ABSTRACT New Caledonia, an archipelago located in the southwest Pacific Ocean, hosts a rich and highly original vascular flora, distributed within a remarkable mosaic of habitats. Despite intensive research on the flora, the diversity and ecology of the climbing flora within the archipelago remain virtually unknown. More globally, while most liana studies have been carried out in continental forests, data from island ecosystems remain scarce. This study aims to document the taxonomic diversity, and to analyze the ecology and functional traits of angiosperms climbers in New Caledonia. Using herbarium data, exhaustive bibliographic review and field studies, we provide a checklist of 274 autochthonous climbing taxa, distributed in 45 families. The majority of climbing plant species in New Caledonia are woody, herbaceous vine being infrequent. Climbing plants account for ~ 8% of the native flora (angiosperms), a rather small contribution compared with continental tropical floras. There is, however, a great heterogeneity in the distribution of climbing plants within the different vegetation, as they represent up to 19% of species in the sclerophyll forests, and only ~ 8 and 6.5% in respectively shrublands (maquis) and rain forests, which are the most original ecosystems in New Caledonia. The endemicity is relatively low (64%) compared to the global flora (75% of endemism). Three endemic genera are exclusively climbers (Artia, Balgoya and Clematepistephium). The diversity of climbing plants is concentrated within few families: ~29% belonging to Apocynaceae and more than half of the species are included in just four families.

Paleoecology provides context for conserving culturally and ecologically important pine forest and barrens communities.

In fire-prone ecosystems, knowledge of vegetation-fire-climate relationships and history of fire suppression and Indigenous cultural burning can inform discussions of how to use fire as a management tool, particularly as climate continues to change rapidly. On Wiisaakodewan-minis/Stockton Island in the Apostle Islands National Lakeshore of Wisconsin, USA, structural changes in a pine-dominated natural area containing a globally rare barrens community occurred after cessation of cultural burning by Indigenous Ojibwe people and the imposition of fire-suppression policies, leading to questions about the historical role of fire in this culturally and ecologically important area. To help better understand the ecological context needed to steward these pine forest and barrens communities, we developed paleoecological records of vegetation, fire, and hydrological change using pollen, charcoal, and testate amoebae preserved in peat and sediment cores collected from bog and lagoon sediments within the pine-dominated landscape. Results indicated that fire has been an integral part of Stockton Island ecology for at least 6000 years. Logging in the early-1900s led to persistent changes in island vegetation, and post-logging fires of the 1920s and 1930s were anomalous in the context of the past millennium, likely reflecting more severe and/or extensive burning than in the past. Before that, the composition and structure of pine forest and barrens changed little, perhaps due to regular low-severity surface fires, which may have occurred with a frequency consistent with Indigenous oral histories (~4-8 years). Higher-severity fire episodes, indicated by large charcoal peaks above background levels in the records, occurred predominantly during droughts, suggesting that more frequent or more intense droughts in the future may increase fire frequency and severity. Persistence of pine forest and barrens vegetation through past periods of climatic change indicates considerable ecological resistance and resilience. Future persistence in the face of climate changes outside this historical range of variability may depend in part on returning fire to these systems. This article is protected by copyright. All rights reserved.

Arthropod-based biotic integrity indices: A novel tool for evaluating the ecological condition of native forests in the Azores archipelago

Island ecosystems are experiencing a significant decline in biodiversity, with forest biodiversity being particularly affected by several biodiversity erosion drivers. This alarming situation highlights the urgent need for conservation managers to develop more accurate and efficient tools to assess and monitor the quality status of sites. To address this issue, our study focuses on the development of two biological integrity indices (IBI) that utilize arthropod communities as indicators to measure the quality of forest sites. In accordance with studies that showed stratification of species diversity, we developed an IBI for canopy stratum (IBI-Canopy) and an IBI for an intermediate stratum targeting the forest understory (IBI-SLAM). We calibrated both indices on seven parameters for comparison purpose with a previous developed epigean IBI. Percentages of endemic, native non-endemic and introduced species richness and abundance were included in both indices. Percentages of Diplopoda species richness and abundance were included in IBI-Canopy and percentages of Saprophagous species richness and abundance were included in IBI-SLAM. As expected species richness and abundance of endemic species were negatively related to disturbance and selected for both IBI. Surprisingly, species richness and abundance of native non-endemic species were positively related to disturbance. The study highlights the limitations of single measurements in detecting all types of pressure sources, and proposes a multi-measurement system to provide a more comprehensive understanding of the overall system conditions. Our efficient and accessible indices confirmed low preservation status in Flores Island compared to Terceira and Pico, consistent with prior empirical studies. Our analyses also showed that canopy detect disturbance earlier than intermediate understory stratum. Our methodology has successfully been developed and tailored to the unique arthropod communities found in the Azores forests. While it may not be suitable for random forest sites, it can serve as a valuable source of inspiration for the development of arthropod-based IBIs in other islands of the world for which standardized endemic and exotic species richness and abundance could be obtained. The study also showed that arthropod assemblages mimicked forest biodiversity stratification and this is reflected in differences expressed by the IBIs.

Seasonal and circadian patterns of herring gull (Larus smithsoniansus) movements reveal temporal shifts in industry and coastal island interaction

AbstractAnthropogenic food subsidies attract opportunistic generalists like gulls in high densities, which may lead to negative impacts on human communities and local ecosystems. Managing impacts requires understanding why gulls use particular natural or industrial sites at different times of day or phases of the breeding cycle. Use of natural and human‐influenced habitats likely varies temporally as gulls alter schedules and site selection to match the predictability of different resources as they vary through space and time relative to patterns in human activities (seasonal industries, the work week, working hours) and natural rhythms (daylight, tide cycles), while gull resource requirements and restrictions to movement also shift with changing reproductive demands.We quantified seasonal and circadian patterns in American herring gull (Larus smithsoniansus) interactions with anthropogenic and natural sites throughout breeding using GPS data from 15 gulls tracked over 3 years from two colonies. We examined the weekly probability of gull occurrence at distinct destinations (e.g. breeding colony, islands, offshore, fish processing plants), and how occurrence varied with time of day, weekday/weekend, tide phase and colony, using GLMMs with a binomial response for destination‐specific occurrence.Probability at the colony varied predictably through the breeding season (highest attendance from dusk to dawn, during incubation and early chick rearing), providing confidence in the modelling approach for detecting temporal patterns in behaviour. Gulls visited other islands mostly outside incubation and early chick rearing, and from dusk through the night, likely roosting. Occurrence offshore where interaction with fishing vessels is possible was highest from dusk to dawn, and differed among colonies, but was the most likely destination during incubation and early chick rearing. Occurrence at fish plants gradually increased until after fledging when attendance was highest from Aug‐Oct coincident with the peak of Atlantic herring (Clupea harengus) processing and was more likely during the weekdays, during working hours, and during low and flood tide.Gulls in southwest Nova Scotia, Canada, have the behavioural flexibility to adapt to both natural rhythms and human schedules when beneficial, enabling them to thrive in a region where industry and natural resources are abundant. These findings can provide information to guide when and where to test different subsidy management strategies locally, while also considering potential increased pressures on island ecosystems. We emphasise that management outcomes of reductions of food subsidies for opportunistic species depend on multiple factors, including availability of alternative food sources and timing of use.

Co-inversion of island leaf area index combination morphological and spectral parameters based on UAV multi-source remote sensing data

The precise and rapid estimation of leaf area index (LAI) is crucial for quantitative ecological monitoring and assessment, as it serves as an important ecological indicator of plant growth state and canopy structure. The acquisition, integration, and application of multiple remote sensing data from Unmanned Aerial Vehicle (UAV) platforms in quantitative ecological research is a current research hotspot. This study aims to explore the potential of combining morphological and spectral parameters using the symbolic regression (SR) algorithm with allometric models to improve the estimation of Leaf Area Index (LAI) at a regional scale of island ecosystem using UAV multi-source remote sensing data. The Canopy Height Model (CHM), Vegetation Density (VD), and Vegetation Indices (VIs), derived from UAV multi-platforms, were used as independent variables in the development of the retrieval models. Subsequently, regression equations were used to construct the Singlet, Duplet, and Triplet models. The precise assessments indicated that the triplet model demonstrates the highest accuracy, with a mean absolute error (MAE) of 9.48% and root mean square error (RMSE) of 0.2345. This improvement was observed compared to the singlet model (MAE = 19.55%, RMSE = 0.4091) and duplet model (MAE = 15.88%, RMSE = 0.3450), which can be attributed to incorporating morphological parameters to reduce the impact of tree height and leaf density. The analysis also showed that the estimated LAI accuracy is generally higher for shrubs and herbs compared to trees, and that lower plants with high vegetation coverage are better retrieved. The methodology advaneced in this study demonstrates significant potential and implications for ecological monitoring and assessment of island ecosystems, thereby expanding the research scope in the field of island ecology. Furthermore, it provides scientific evidence and technical support for decision-makers and scholars to propose and implement various measures for the conservation and restoration of island ecosystems.