Jacob Virtue, Darren Turner, Guy Williams, Stephanie Zeliadt, Arko Lucieer
Monitoring seabird populations is increasingly urgent as numerous species become more vulnerable to climate change and urbanisation. Surveying burrow‐nesting seabirds is challenging due to their nocturnal behaviour, the inaccessibility of colonies, and the disturbance that monitoring poses to nesting sites. Traditional survey methods, which are manual transects conducted by researchers (~200 m), extrapolate this data to derive the population estimates of entire colonies. To enhance the accuracy beyond interpolated data, a survey method was developed using Unoccupied Aerial Systems (UAS) equipped with thermal sensors to survey short‐tailed shearwaters (Ardenna tenuirostris). Thermal imagery of breeding colonies was collected from 2019 to 2024, providing comprehensive coverage capturing all occupied burrows (chick presence) at each colony. Occupied burrow densities decreased from 0.28 to 0.18 burrows per m2 over this period. Chick numbers decreased by 27% from 2019 (6129) to 2024 (4445). Burrow occupancy counts varied widely (0%–66%) with transect location, highlighting the advantages of using UAS‐mounted thermal sensors for providing spatially complete data. This indicates that counts are not uniform, highlighting the bias of using transect data to estimate chick production. A series of simulated transects were imposed over the thermal imagery to compare whole colony chick counts with extrapolated counts. Using data from this study, we estimated that the global breeding population of short‐tailed shearwaters is currently 13.5 million, which is approximately 41% less than the last reported global estimate in 1985 of 23 million. This study highlights the utility of emerging technology that addresses the challenges of studying species that are nocturnally active or in remote/inaccessible habitats.
{"title":"Thermal drone observations capture fine‐scale population decline of short‐tailed shearwaters","authors":"Jacob Virtue, Darren Turner, Guy Williams, Stephanie Zeliadt, Arko Lucieer","doi":"10.1002/rse2.70020","DOIUrl":"https://doi.org/10.1002/rse2.70020","url":null,"abstract":"Monitoring seabird populations is increasingly urgent as numerous species become more vulnerable to climate change and urbanisation. Surveying burrow‐nesting seabirds is challenging due to their nocturnal behaviour, the inaccessibility of colonies, and the disturbance that monitoring poses to nesting sites. Traditional survey methods, which are manual transects conducted by researchers (~200 m), extrapolate this data to derive the population estimates of entire colonies. To enhance the accuracy beyond interpolated data, a survey method was developed using Unoccupied Aerial Systems (UAS) equipped with thermal sensors to survey short‐tailed shearwaters (<jats:italic>Ardenna tenuirostris</jats:italic>). Thermal imagery of breeding colonies was collected from 2019 to 2024, providing comprehensive coverage capturing all occupied burrows (chick presence) at each colony. Occupied burrow densities decreased from 0.28 to 0.18 burrows per m<jats:sup>2</jats:sup> over this period. Chick numbers decreased by 27% from 2019 (6129) to 2024 (4445). Burrow occupancy counts varied widely (0%–66%) with transect location, highlighting the advantages of using UAS‐mounted thermal sensors for providing spatially complete data. This indicates that counts are not uniform, highlighting the bias of using transect data to estimate chick production. A series of simulated transects were imposed over the thermal imagery to compare whole colony chick counts with extrapolated counts. Using data from this study, we estimated that the global breeding population of short‐tailed shearwaters is currently 13.5 million, which is approximately 41% less than the last reported global estimate in 1985 of 23 million. This study highlights the utility of emerging technology that addresses the challenges of studying species that are nocturnally active or in remote/inaccessible habitats.","PeriodicalId":21132,"journal":{"name":"Remote Sensing in Ecology and Conservation","volume":"119 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144763123","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
José Luis Hernández‐Stefanoni, Luis A. Hernández‐Martínez, Juan Andres‐Mauricio, Víctor Alexis Peña‐Lara, Karina Elizabeth González‐Muñoz, Fernando Tun‐Dzul, Carlos A. Portillo‐Quintero, Eric Antonio Gamboa‐Blanco, Stephanie George‐Chacon
Accurate assessment of forest aboveground biomass density (AGBD) is essential for understanding the role of vegetation in climate change mitigation and developing forest management and environmental policies at national and regional levels. The Global Ecosystem Dynamics Investigation (GEDI) uses full‐waveform LiDAR and provides a valuable tool for estimating AGBD. Calibrating GEDI biomass products with local field data is vital for improving model accuracy, as current estimates rely on global datasets. Additionally, evaluating key factors that influence biomass estimation is essential to refine GEDI‐based models. In this research, we calibrated linear models with field AGBD as the dependent variable and GEDI metrics as independent variables, and compared the performance against the GEDI L4A product across forest types. Additionally, we evaluated the effects of terrain slope, forest structural complexity, and forest type on the accuracy of the models. Finally, we mapped AGBD in Mexico by aggregating footprint‐level estimates with local models and compared it with the GEDI AGBD map (L4B product). Model validation showed R2 values from 0.35 to 0.46 across forest types, with most models having %RMSE below 52.0. Errors were 32.7 to 34.2% lower than GEDI L4A, highlighting a notable accuracy improvement. The total carbon stocks in Mexico estimated here are approximately 1.78 Gt, aligning closely with official FAO estimates, whereas GEDI estimates are 33.5% higher than the official estimate. Biomass estimation with GEDI is most accurate in areas with moderate slopes and low forest structural complexity. Coniferous and tropical forests showed the lowest errors in estimating AGBD with GEDI (46.7 and 47.3 of %RMSE, respectively) likely due to the widespread presence of uniformly structured coniferous trees and the moderate terrain slopes found in tropical forests. Our findings highlight the importance of calibrating local AGBD data with GEDI forest structure metrics to improve biomass estimations at the footprint and national levels.
{"title":"Spatial distribution and drivers of aboveground forest biomass in Mexico using GEDI and national forest inventory data","authors":"José Luis Hernández‐Stefanoni, Luis A. Hernández‐Martínez, Juan Andres‐Mauricio, Víctor Alexis Peña‐Lara, Karina Elizabeth González‐Muñoz, Fernando Tun‐Dzul, Carlos A. Portillo‐Quintero, Eric Antonio Gamboa‐Blanco, Stephanie George‐Chacon","doi":"10.1002/rse2.70019","DOIUrl":"https://doi.org/10.1002/rse2.70019","url":null,"abstract":"Accurate assessment of forest aboveground biomass density (AGBD) is essential for understanding the role of vegetation in climate change mitigation and developing forest management and environmental policies at national and regional levels. The Global Ecosystem Dynamics Investigation (GEDI) uses full‐waveform LiDAR and provides a valuable tool for estimating AGBD. Calibrating GEDI biomass products with local field data is vital for improving model accuracy, as current estimates rely on global datasets. Additionally, evaluating key factors that influence biomass estimation is essential to refine GEDI‐based models. In this research, we calibrated linear models with field AGBD as the dependent variable and GEDI metrics as independent variables, and compared the performance against the GEDI L4A product across forest types. Additionally, we evaluated the effects of terrain slope, forest structural complexity, and forest type on the accuracy of the models. Finally, we mapped AGBD in Mexico by aggregating footprint‐level estimates with local models and compared it with the GEDI AGBD map (L4B product). Model validation showed <jats:italic>R</jats:italic><jats:sup>2</jats:sup> values from 0.35 to 0.46 across forest types, with most models having %RMSE below 52.0. Errors were 32.7 to 34.2% lower than GEDI L4A, highlighting a notable accuracy improvement. The total carbon stocks in Mexico estimated here are approximately 1.78 Gt, aligning closely with official FAO estimates, whereas GEDI estimates are 33.5% higher than the official estimate. Biomass estimation with GEDI is most accurate in areas with moderate slopes and low forest structural complexity. Coniferous and tropical forests showed the lowest errors in estimating AGBD with GEDI (46.7 and 47.3 of %RMSE, respectively) likely due to the widespread presence of uniformly structured coniferous trees and the moderate terrain slopes found in tropical forests. Our findings highlight the importance of calibrating local AGBD data with GEDI forest structure metrics to improve biomass estimations at the footprint and national levels.","PeriodicalId":21132,"journal":{"name":"Remote Sensing in Ecology and Conservation","volume":"14 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144669664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Francesco D'Adamo, Rebecca Spake, James M. Bullock, Booker Ogutu, Jadunandan Dash, Felix Eigenbrod
Identifying the drivers of ecosystem dynamics, and how responses vary spatially and temporally, is a critical challenge in the face of global change. Grasslands in sub‐Saharan Africa are vital ecosystems supporting biodiversity, carbon storage, and livelihoods through grazing. However, despite their importance, the processes driving change in these systems remain poorly understood, as cross‐scale interactions among drivers produce complex, context‐dependent dynamics that vary across space and time. This is particularly relevant for woody vegetation dynamics, which are often linked to degradation processes (e.g., woody encroachment), with consequences for biodiversity, forage availability, and fire regimes. Here, we used satellite data and structural equation models to investigate the effects of rainfall, temperature, fire, and population density on woody vegetation dynamics in four African grassland regions (the Sahel grasslands, Greater Karoo and Kalahari drylands, Southeast African subtropical grasslands, and Madagascar) during 1997–2016. Across all regions, rainfall was consistently positively correlated with increased woody vegetation, while higher temperatures were associated with decreased woody vegetation, suggesting that water availability promotes woody plant growth, whereas rising aridity limits it. Unexpectedly, fire had a negative effect on woody cover only in the Greater Karoo and Kalahari drylands, while in Madagascar, higher temperatures and greater population density reduced fire; yet these relationships did not translate into significant indirect effects on woody vegetation. These findings illustrate the complex ways by which environmental and anthropogenic drivers shape woody vegetation dynamics in grasslands across sub‐Saharan Africa. Compared to savannas, fire plays a weaker and more region‐specific role in grasslands, where its feedback with woody cover is less consistent. The opposing effects of rainfall and temperature may currently constrain woody expansion, but climate change could disrupt this balance and further weaken fire's limited regulatory role. These differences highlight the need for management strategies tailored to the distinct climate–vegetation dynamics of grassland systems.
{"title":"Precipitation and temperature drive woody vegetation dynamics in the grasslands of sub‐Saharan Africa","authors":"Francesco D'Adamo, Rebecca Spake, James M. Bullock, Booker Ogutu, Jadunandan Dash, Felix Eigenbrod","doi":"10.1002/rse2.70018","DOIUrl":"https://doi.org/10.1002/rse2.70018","url":null,"abstract":"Identifying the drivers of ecosystem dynamics, and how responses vary spatially and temporally, is a critical challenge in the face of global change. Grasslands in sub‐Saharan Africa are vital ecosystems supporting biodiversity, carbon storage, and livelihoods through grazing. However, despite their importance, the processes driving change in these systems remain poorly understood, as cross‐scale interactions among drivers produce complex, context‐dependent dynamics that vary across space and time. This is particularly relevant for woody vegetation dynamics, which are often linked to degradation processes (e.g., woody encroachment), with consequences for biodiversity, forage availability, and fire regimes. Here, we used satellite data and structural equation models to investigate the effects of rainfall, temperature, fire, and population density on woody vegetation dynamics in four African grassland regions (the Sahel grasslands, Greater Karoo and Kalahari drylands, Southeast African subtropical grasslands, and Madagascar) during 1997–2016. Across all regions, rainfall was consistently positively correlated with increased woody vegetation, while higher temperatures were associated with decreased woody vegetation, suggesting that water availability promotes woody plant growth, whereas rising aridity limits it. Unexpectedly, fire had a negative effect on woody cover only in the Greater Karoo and Kalahari drylands, while in Madagascar, higher temperatures and greater population density reduced fire; yet these relationships did not translate into significant indirect effects on woody vegetation. These findings illustrate the complex ways by which environmental and anthropogenic drivers shape woody vegetation dynamics in grasslands across sub‐Saharan Africa. Compared to savannas, fire plays a weaker and more region‐specific role in grasslands, where its feedback with woody cover is less consistent. The opposing effects of rainfall and temperature may currently constrain woody expansion, but climate change could disrupt this balance and further weaken fire's limited regulatory role. These differences highlight the need for management strategies tailored to the distinct climate–vegetation dynamics of grassland systems.","PeriodicalId":21132,"journal":{"name":"Remote Sensing in Ecology and Conservation","volume":"13 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144629804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Camille Goudalier, David Mouillot, Léa Bernagou, Taha Boksmati, Caulvyn Bristol, Harry Clark, Sekar M.C. Herandarudewi, Régis Hocdé, Anna Koester, Ashlie J. McIvor, Dhivya Nair, Muhammad Rizki Nandika, Louisa Ponnampalam, Achmad Sahri, Evan Trotzuk, Nur Abidah Zaaba, Laura Mannocci
The monitoring of body condition, reflecting the state of individuals' energetic reserves, can provide early warning signals of population decline, facilitating prompt conservation actions. However, environmental and anthropogenic drivers of body condition are poorly known for rare and elusive marine mammal species over their entire ranges. We assessed the global patterns and drivers of body condition for the endangered dugong (Dugong dugon) across its Indo‐Pacific range. To do so, we applied the body condition index (BCI) developed for the related manatee based on the ratio of umbilical girth (approximated as maximum width times π), to straight body length measured in drone images. To cover the entire dugong's range, we took advantage of drone footage published on social media. Combined with footage from scientific surveys, social media footage provided body condition estimates for 272 individual dugongs across 18 countries. Despite small sample sizes relative to local population sizes, we found that dugong BCI was better, that is, individuals were ‘plumper’, in New Caledonia, the United Arab Emirates, Australia and Qatar where populations are the largest globally. Dugong BCI was comparatively poorer in countries hosting very small dugong populations such as Mozambique, suggesting a link between body condition and population size. Using statistical models, we then investigated potential environmental and anthropogenic drivers of dugong BCI, while controlling for seasonal and individual effects. The BCI decreased with human gravity, a variable integrating human pressures on tropical reefs, but increased with GDP per capita, indicating that economic wealth positively affects dugong energetic state. The BCI also showed a dome‐shaped relationship with marine protected area coverage, suggesting that extensive spatial protection is not sufficient to maintain dugongs in good state. Our study provides the first assessment of dugong body condition through drone photogrammetry, underlining the value of this non‐invasive, fast and low‐cost approach for monitoring elusive marine mammals.
{"title":"Drone photogrammetry reveals contrasting body conditions of dugongs across the Indo‐Pacific","authors":"Camille Goudalier, David Mouillot, Léa Bernagou, Taha Boksmati, Caulvyn Bristol, Harry Clark, Sekar M.C. Herandarudewi, Régis Hocdé, Anna Koester, Ashlie J. McIvor, Dhivya Nair, Muhammad Rizki Nandika, Louisa Ponnampalam, Achmad Sahri, Evan Trotzuk, Nur Abidah Zaaba, Laura Mannocci","doi":"10.1002/rse2.70016","DOIUrl":"https://doi.org/10.1002/rse2.70016","url":null,"abstract":"The monitoring of body condition, reflecting the state of individuals' energetic reserves, can provide early warning signals of population decline, facilitating prompt conservation actions. However, environmental and anthropogenic drivers of body condition are poorly known for rare and elusive marine mammal species over their entire ranges. We assessed the global patterns and drivers of body condition for the endangered dugong (<jats:italic>Dugong dugon</jats:italic>) across its Indo‐Pacific range. To do so, we applied the body condition index (BCI) developed for the related manatee based on the ratio of umbilical girth (approximated as maximum width times π), to straight body length measured in drone images. To cover the entire dugong's range, we took advantage of drone footage published on social media. Combined with footage from scientific surveys, social media footage provided body condition estimates for 272 individual dugongs across 18 countries. Despite small sample sizes relative to local population sizes, we found that dugong BCI was better, that is, individuals were ‘plumper’, in New Caledonia, the United Arab Emirates, Australia and Qatar where populations are the largest globally. Dugong BCI was comparatively poorer in countries hosting very small dugong populations such as Mozambique, suggesting a link between body condition and population size. Using statistical models, we then investigated potential environmental and anthropogenic drivers of dugong BCI, while controlling for seasonal and individual effects. The BCI decreased with human gravity, a variable integrating human pressures on tropical reefs, but increased with GDP per capita, indicating that economic wealth positively affects dugong energetic state. The BCI also showed a dome‐shaped relationship with marine protected area coverage, suggesting that extensive spatial protection is not sufficient to maintain dugongs in good state. Our study provides the first assessment of dugong body condition through drone photogrammetry, underlining the value of this non‐invasive, fast and low‐cost approach for monitoring elusive marine mammals.","PeriodicalId":21132,"journal":{"name":"Remote Sensing in Ecology and Conservation","volume":"644 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144341173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Franziska Wolff, Tiina H. M. Kolari, Aleksi Räsänen, Teemu Tahvanainen, Pasi Korpelainen, Miguel Villoslada, Mariana Verdonen, Eliisa Lotsari, Yuwen Pang, Timo Kumpula
Unoccupied Aerial Vehicle (UAV) imagery is widely used for detailed vegetation modeling and ecosystem monitoring in peatlands. Despite high‐resolution data, the spatial complexity and heterogeneity of vegetation, along with temporal fluctuations in spectral reflectance, complicate the assessment of spatial patterns in these ecosystems. We used interannual multispectral UAV data, collected at the same time of the year, from two aapa and two palsa mires in Finland. We applied Random Forest classification to map plant communities and assessed spectral, temporal and spatial consistency, class relationships and area estimates. Further, we used the class membership probabilities from the classification to derive a secondary classification map, representing the second most likely class label per‐pixel and an alternative map to account for spatial uncertainty in area estimates. The accuracies of the primary classifications varied between 66 and 85%. The best results were achieved using interannual data, improving accuracy by up to 14%‐points when compared to single‐year imagery, particularly benefiting classes with lower accuracies. Spectral and temporal inconsistencies in the UAV data collected in different years led to variations in the classifications, notably for the Rubus chamaemorus community in palsa mires, likely due to weather fluctuations and phenology. The transformations from primary to secondary classifications in areas of high uncertainty aligned well with the class relationships in the confusion matrix, supporting the model's reliability. Confidence interval‐based adjusted estimates aligned largely with unadjusted area estimates of the alternative map. Our findings support incorporating class membership probabilities and alternative maps to capture spatially explicit uncertainty, especially when spatial variability is high or key plant communities are involved. Our presented approach is particularly beneficial for upscaling ecological processes, such as carbon fluxes, where spatial variability is driven by plant community distribution and where informed decision‐making requires detailed spatial assessments.
{"title":"Interannual spectral consistency and spatial uncertainties in UAV‐based detection of boreal and subarctic mire plant communities","authors":"Franziska Wolff, Tiina H. M. Kolari, Aleksi Räsänen, Teemu Tahvanainen, Pasi Korpelainen, Miguel Villoslada, Mariana Verdonen, Eliisa Lotsari, Yuwen Pang, Timo Kumpula","doi":"10.1002/rse2.70017","DOIUrl":"https://doi.org/10.1002/rse2.70017","url":null,"abstract":"Unoccupied Aerial Vehicle (UAV) imagery is widely used for detailed vegetation modeling and ecosystem monitoring in peatlands. Despite high‐resolution data, the spatial complexity and heterogeneity of vegetation, along with temporal fluctuations in spectral reflectance, complicate the assessment of spatial patterns in these ecosystems. We used interannual multispectral UAV data, collected at the same time of the year, from two aapa and two palsa mires in Finland. We applied Random Forest classification to map plant communities and assessed spectral, temporal and spatial consistency, class relationships and area estimates. Further, we used the class membership probabilities from the classification to derive a secondary classification map, representing the second most likely class label per‐pixel and an alternative map to account for spatial uncertainty in area estimates. The accuracies of the primary classifications varied between 66 and 85%. The best results were achieved using interannual data, improving accuracy by up to 14%‐points when compared to single‐year imagery, particularly benefiting classes with lower accuracies. Spectral and temporal inconsistencies in the UAV data collected in different years led to variations in the classifications, notably for the <jats:italic>Rubus chamaemorus</jats:italic> community in palsa mires, likely due to weather fluctuations and phenology. The transformations from primary to secondary classifications in areas of high uncertainty aligned well with the class relationships in the confusion matrix, supporting the model's reliability. Confidence interval‐based adjusted estimates aligned largely with unadjusted area estimates of the alternative map. Our findings support incorporating class membership probabilities and alternative maps to capture spatially explicit uncertainty, especially when spatial variability is high or key plant communities are involved. Our presented approach is particularly beneficial for upscaling ecological processes, such as carbon fluxes, where spatial variability is driven by plant community distribution and where informed decision‐making requires detailed spatial assessments.","PeriodicalId":21132,"journal":{"name":"Remote Sensing in Ecology and Conservation","volume":"15 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144341174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Marius Somveille, Joe Grainger‐Hull, Nicole Ferguson, Sarab S. Sethi, Fernando González‐García, Valentine Chassagnon, Cansu Oktem, Mathias Disney, Gustavo López Bautista, John Vandermeer, Ivette Perfecto
Land use change associated with agricultural intensification is a leading driver of biodiversity loss in the tropics. To evaluate the habitat–biodiversity relationship in production systems of tropical agricultural commodities, birds are commonly used as indicators. However, a consistent and reliable methodological approach for monitoring tropical avian communities and habitat quality in a way that is scalable is largely lacking. In this study, we examined whether the automated analysis of audio data collected by passive acoustic monitoring, together with the analysis of remote sensing data, can be used to efficiently monitor avian biodiversity along the gradient of habitat degradation associated with the intensification of coffee production. Coffee is an important crop produced in tropical forested regions, whose production is expanding and intensifying, and coffee production systems form a gradient of ecological complexity ranging from forest‐like shaded polyculture to dense sun‐exposed monoculture. We used LiDAR technology to survey the habitat, together with autonomous recording units and a vocalization classifier to assess bird community composition in a coffee landscape comprising a shade‐grown coffee farm, a sun coffee farm and a forest remnant, located in southern Mexico. We found that LiDAR can capture relevant variation in vegetation across the habitat gradient in coffee systems, specifically matching the generally observed pattern that the intensification of coffee production is associated with a decrease in vegetation density and complexity. We also found that bioacoustics can capture known functional signatures of avian communities across this habitat degradation gradient. Thus, we show that these technologies can be used in a robust way to monitor how biodiversity responds to land use intensification in the tropics. A major advantage of this approach is that it has the potential to be deployed cost‐effectively at large scales to help design and certify biodiversity‐friendly productive landscapes.
{"title":"Consistent and scalable monitoring of birds and habitats along a coffee production intensity gradient","authors":"Marius Somveille, Joe Grainger‐Hull, Nicole Ferguson, Sarab S. Sethi, Fernando González‐García, Valentine Chassagnon, Cansu Oktem, Mathias Disney, Gustavo López Bautista, John Vandermeer, Ivette Perfecto","doi":"10.1002/rse2.70015","DOIUrl":"https://doi.org/10.1002/rse2.70015","url":null,"abstract":"Land use change associated with agricultural intensification is a leading driver of biodiversity loss in the tropics. To evaluate the habitat–biodiversity relationship in production systems of tropical agricultural commodities, birds are commonly used as indicators. However, a consistent and reliable methodological approach for monitoring tropical avian communities and habitat quality in a way that is scalable is largely lacking. In this study, we examined whether the automated analysis of audio data collected by passive acoustic monitoring, together with the analysis of remote sensing data, can be used to efficiently monitor avian biodiversity along the gradient of habitat degradation associated with the intensification of coffee production. Coffee is an important crop produced in tropical forested regions, whose production is expanding and intensifying, and coffee production systems form a gradient of ecological complexity ranging from forest‐like shaded polyculture to dense sun‐exposed monoculture. We used LiDAR technology to survey the habitat, together with autonomous recording units and a vocalization classifier to assess bird community composition in a coffee landscape comprising a shade‐grown coffee farm, a sun coffee farm and a forest remnant, located in southern Mexico. We found that LiDAR can capture relevant variation in vegetation across the habitat gradient in coffee systems, specifically matching the generally observed pattern that the intensification of coffee production is associated with a decrease in vegetation density and complexity. We also found that bioacoustics can capture known functional signatures of avian communities across this habitat degradation gradient. Thus, we show that these technologies can be used in a robust way to monitor how biodiversity responds to land use intensification in the tropics. A major advantage of this approach is that it has the potential to be deployed cost‐effectively at large scales to help design and certify biodiversity‐friendly productive landscapes.","PeriodicalId":21132,"journal":{"name":"Remote Sensing in Ecology and Conservation","volume":"16 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144337521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ryan C. Blackburn, Robert Buscaglia, Andrew J. Sánchez Meador, Margaret M. Moore, Temuulen Sankey, Steven E. Sesnie
Accurately classifying tree species using remotely sensed data remains a significant challenge, yet it is essential for forest monitoring and understanding ecosystem dynamics over large spatial extents. While light detection and ranging (lidar) has shown promise for species classification, its accuracy typically decreases in complex forests or with lower lidar point densities. Recent advancements in lidar processing and machine learning offer new opportunities to leverage previously unavailable structural information. In this study, we present an automated machine learning pipeline that reduces practitioner burden by utilizing canonical deep learning and improved input layers through the derivation of eigenfeatures. These eigenfeatures were used as inputs for a 2D convolutional neural network (CNN) to classify seven tree species in the Mogollon Rim Ranger District of the Coconino National Forest, AZ, US. We compared eigenfeature images derived from unoccupied aerial vehicle laser scanning (UAV‐LS) and airborne laser scanning (ALS) individual tree segmentation algorithms against raw intensity and colorless control images. Remarkably, mean overall accuracies for classifying seven species reached 94.8% for ALS and 93.4% for UAV‐LS. White image types underperformed for both ALS and UAV‐LS compared to eigenfeature images, while ALS and UAV‐LS image types showed marginal differences in model performance. These results demonstrate that lower point density ALS data can achieve high classification accuracy when paired with eigenfeatures in an automated pipeline. This study advances the field by addressing species classification at scales ranging from individual trees to landscapes, offering a scalable and efficient approach for understanding tree composition in complex forests.
{"title":"Eigenfeature‐enhanced deep learning: advancing tree species classification in mixed conifer forests with lidar","authors":"Ryan C. Blackburn, Robert Buscaglia, Andrew J. Sánchez Meador, Margaret M. Moore, Temuulen Sankey, Steven E. Sesnie","doi":"10.1002/rse2.70014","DOIUrl":"https://doi.org/10.1002/rse2.70014","url":null,"abstract":"Accurately classifying tree species using remotely sensed data remains a significant challenge, yet it is essential for forest monitoring and understanding ecosystem dynamics over large spatial extents. While light detection and ranging (lidar) has shown promise for species classification, its accuracy typically decreases in complex forests or with lower lidar point densities. Recent advancements in lidar processing and machine learning offer new opportunities to leverage previously unavailable structural information. In this study, we present an automated machine learning pipeline that reduces practitioner burden by utilizing canonical deep learning and improved input layers through the derivation of eigenfeatures. These eigenfeatures were used as inputs for a 2D convolutional neural network (CNN) to classify seven tree species in the Mogollon Rim Ranger District of the Coconino National Forest, AZ, US. We compared eigenfeature images derived from unoccupied aerial vehicle laser scanning (UAV‐LS) and airborne laser scanning (ALS) individual tree segmentation algorithms against raw intensity and colorless control images. Remarkably, mean overall accuracies for classifying seven species reached 94.8% for ALS and 93.4% for UAV‐LS. White image types underperformed for both ALS and UAV‐LS compared to eigenfeature images, while ALS and UAV‐LS image types showed marginal differences in model performance. These results demonstrate that lower point density ALS data can achieve high classification accuracy when paired with eigenfeatures in an automated pipeline. This study advances the field by addressing species classification at scales ranging from individual trees to landscapes, offering a scalable and efficient approach for understanding tree composition in complex forests.","PeriodicalId":21132,"journal":{"name":"Remote Sensing in Ecology and Conservation","volume":"47 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144252281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Heng Zhang, Carmen Meiller, Andreas Hueni, Rosetta C. Blackman, Felix Morsdorf, Isabelle S. Helfenstein, Michael E. Schaepman, Florian Altermatt
Different organismal functional feeding groups (FFGs) are key components of aquatic food webs and are important for sustaining ecosystem functioning in riverine ecosystems. Their distribution and diversity are tightly associated with the surrounding terrestrial landscape through land‐water linkages. Nevertheless, knowledge about the spatial extent and magnitude of these cross‐ecosystem linkages within major FFGs still remains unclear. Here, we conducted an airborne imaging spectroscopy campaign and a systematic environmental DNA (eDNA) field sampling of river water in a 740‐km2 mountainous catchment, combined with light detection and ranging (LiDAR) point clouds, to obtain the spectral and morphological diversity of the terrestrial landscape and the diversity of major FFGs in rivers. We identified the scale of these linkages, ranging from a few hundred meters to more than 10 km, with collectors and filterers, shredders, and small invertebrate predators having local‐scale associations, while invertebrate‐eating fish, grazers, and scrapers have more landscape‐scale associations. Among all major FFGs, shredders, grazers, and scrapers in the streams had the strongest association with surrounding terrestrial vegetation. Our research reveals the reference spatial scales at which major FFGs are linked to the surrounding terrestrial landscape, providing spatially explicit evidence of the cross‐ecosystem linkages needed for conservation design and management.
{"title":"Hyperspectral imagery, LiDAR point clouds, and environmental DNA to assess land‐water linkage of biodiversity across aquatic functional feeding groups","authors":"Heng Zhang, Carmen Meiller, Andreas Hueni, Rosetta C. Blackman, Felix Morsdorf, Isabelle S. Helfenstein, Michael E. Schaepman, Florian Altermatt","doi":"10.1002/rse2.70010","DOIUrl":"https://doi.org/10.1002/rse2.70010","url":null,"abstract":"Different organismal functional feeding groups (FFGs) are key components of aquatic food webs and are important for sustaining ecosystem functioning in riverine ecosystems. Their distribution and diversity are tightly associated with the surrounding terrestrial landscape through land‐water linkages. Nevertheless, knowledge about the spatial extent and magnitude of these cross‐ecosystem linkages within major FFGs still remains unclear. Here, we conducted an airborne imaging spectroscopy campaign and a systematic environmental DNA (eDNA) field sampling of river water in a 740‐km<jats:sup>2</jats:sup> mountainous catchment, combined with light detection and ranging (LiDAR) point clouds, to obtain the spectral and morphological diversity of the terrestrial landscape and the diversity of major FFGs in rivers. We identified the scale of these linkages, ranging from a few hundred meters to more than 10 km, with collectors and filterers, shredders, and small invertebrate predators having local‐scale associations, while invertebrate‐eating fish, grazers, and scrapers have more landscape‐scale associations. Among all major FFGs, shredders, grazers, and scrapers in the streams had the strongest association with surrounding terrestrial vegetation. Our research reveals the reference spatial scales at which major FFGs are linked to the surrounding terrestrial landscape, providing spatially explicit evidence of the cross‐ecosystem linkages needed for conservation design and management.","PeriodicalId":21132,"journal":{"name":"Remote Sensing in Ecology and Conservation","volume":"25 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144192865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Guillaume Tougas, Christine I. B. Wallis, Etienne Laliberté, Mark Vellend
Insect and pathogen outbreaks have a major impact on northern forest ecosystems. Even for pathogens that have been present in a region for decades, such as beech bark disease (BBD), new waves of tree mortality are expected. Hence, there is a need for innovative approaches to monitor disease advancement in real time. Here, we test whether airborne hyperspectral imaging – involving data from 344 wavelengths in the visible, near infrared (NIR) and short‐wave infrared (SWIR) – can be used to assess beech bark disease severity in southern Quebec, Canada. Field data on disease severity were linked to airborne hyperspectral data for individual beech crowns. Partial least‐squares regression (PLSR) models using airborne imaging spectroscopy data predicted a small proportion of the variance in beech bark disease severity: the best model had an R2 of only 0.09. Wavelengths with the strongest contributions were from the red‐edge region (~715 nm) and the SWIR (~1287 nm), which may suggest mediation by canopy greenness, water content, and canopy architecture. Similar models using hyperspectral data taken directly on individual leaves had no explanatory power (R2 = 0). In addition, airborne and leaf‐level hyperspectral datasets were uncorrelated. The failure of leaf‐level models suggests that canopy structure was likely responsible for the limited predictive ability of the airborne model. Somewhat better performance in predicting disease severity was found using common band ratios for canopy greenness assessment (e.g., the Green Normalized Difference Vegetation Index, gNDVI, and the Normalized Phaeophytinization Index, NPQI); these variables explained up to 19% of the variation in disease severity. Overall, we argue that the complexity of hyperspectral data is not necessary for assessing BBD spread and that spectral data in general may not provide an efficient means of improving BBD monitoring on a larger scale.
{"title":"Hyperspectral imaging has a limited ability to remotely sense the onset of beech bark disease","authors":"Guillaume Tougas, Christine I. B. Wallis, Etienne Laliberté, Mark Vellend","doi":"10.1002/rse2.70013","DOIUrl":"https://doi.org/10.1002/rse2.70013","url":null,"abstract":"Insect and pathogen outbreaks have a major impact on northern forest ecosystems. Even for pathogens that have been present in a region for decades, such as beech bark disease (BBD), new waves of tree mortality are expected. Hence, there is a need for innovative approaches to monitor disease advancement in real time. Here, we test whether airborne hyperspectral imaging – involving data from 344 wavelengths in the visible, near infrared (NIR) and short‐wave infrared (SWIR) – can be used to assess beech bark disease severity in southern Quebec, Canada. Field data on disease severity were linked to airborne hyperspectral data for individual beech crowns. Partial least‐squares regression (PLSR) models using airborne imaging spectroscopy data predicted a small proportion of the variance in beech bark disease severity: the best model had an <jats:italic>R</jats:italic><jats:sup>2</jats:sup> of only 0.09. Wavelengths with the strongest contributions were from the red‐edge region (~715 nm) and the SWIR (~1287 nm), which may suggest mediation by canopy greenness, water content, and canopy architecture. Similar models using hyperspectral data taken directly on individual leaves had no explanatory power (<jats:italic>R</jats:italic><jats:sup>2</jats:sup> = 0). In addition, airborne and leaf‐level hyperspectral datasets were uncorrelated. The failure of leaf‐level models suggests that canopy structure was likely responsible for the limited predictive ability of the airborne model. Somewhat better performance in predicting disease severity was found using common band ratios for canopy greenness assessment (e.g., the Green Normalized Difference Vegetation Index, gNDVI, and the Normalized Phaeophytinization Index, NPQI); these variables explained up to 19% of the variation in disease severity. Overall, we argue that the complexity of hyperspectral data is not necessary for assessing BBD spread and that spectral data in general may not provide an efficient means of improving BBD monitoring on a larger scale.","PeriodicalId":21132,"journal":{"name":"Remote Sensing in Ecology and Conservation","volume":"41 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144183762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. R. Sharpe, R. A. Hill, H. M. Chappell, S. E. Green, K. Holden, P. Fergus, C. Chalmers, P. A. Stephens
As camera traps have become more widely used, extracting information from images at the pace they are acquired has become challenging, resulting in backlogs that delay the communication of results and the use of data for conservation and management. To ameliorate this, artificial intelligence (AI), crowdsourcing to citizen scientists and combined approaches have surfaced as solutions. Using data from the UK mammal monitoring initiative MammalWeb, we assess the accuracies of classifications from registered citizen scientists, anonymous participants and a convolutional neural network (CNN). The engagement of anonymous volunteers was facilitated by the strategic placement of MammalWeb interfaces in a natural history museum with high footfall related to the ‘Dippy on Tour’ exhibition. The accuracy of anonymous volunteer classifications gathered through public interfaces has not been reported previously, and here we consider this form of citizen science in the context of alternative forms of data acquisition. While AI models have performed well at species identification in bespoke settings, here we report model performance on a dataset for which the model in question was not explicitly trained. We also consider combining AI output with that of human volunteers to demonstrate combined workflows that produce high accuracy predictions. We find the consensus of registered users has greater overall accuracy (97%) than the consensus from anonymous contributors (71%); AI accuracy lies in between (78%). A combined approach between registered citizen scientists and AI output provides an overall accuracy of 96%. Further, when the contributions of anonymous citizen scientists are concordant with AI output, 98% accuracy can be achieved. The generality of this last finding merits further investigation, given the potential to gather classifications much more rapidly if public displays are placed in areas of high footfall. We suggest that combined approaches to image classification are optimal when the minimisation of classification errors is desired.
随着相机陷阱的应用越来越广泛，从获取图像的速度中提取信息变得具有挑战性，导致积压，从而延迟了结果的交流和数据的保护和管理使用。为了改善这种情况，人工智能（AI）、向公民科学家众包以及综合方法已经浮出水面。使用来自英国哺乳动物监测倡议MammalWeb的数据，我们评估了注册公民科学家，匿名参与者和卷积神经网络（CNN）分类的准确性。通过将MammalWeb界面战略性地放置在自然历史博物馆中，促进了匿名志愿者的参与，该博物馆与“Dippy on Tour”展览有关。通过公共接口收集的匿名志愿者分类的准确性以前没有报道过，在这里，我们在其他数据获取形式的背景下考虑这种形式的公民科学。虽然人工智能模型在定制设置的物种识别方面表现良好，但在这里，我们报告了模型在未明确训练的数据集上的表现。我们还考虑将人工智能输出与人类志愿者的输出相结合，以展示产生高精度预测的组合工作流程。我们发现注册用户的共识总体准确性（97%）高于匿名贡献者的共识（71%）；人工智能的准确率介于两者之间（78%）。注册公民科学家和人工智能输出的结合方法提供了96%的总体准确性。此外，当匿名公民科学家的贡献与人工智能输出一致时，准确率可以达到98%。考虑到如果将公共展览放置在人流量大的地方，可能会更快地收集分类信息，最后这一发现的普遍性值得进一步调查。我们建议，当分类误差最小化时，组合方法对图像分类是最佳的。
{"title":"Increasing citizen scientist accuracy with artificial intelligence on UK camera‐trap data","authors":"C. R. Sharpe, R. A. Hill, H. M. Chappell, S. E. Green, K. Holden, P. Fergus, C. Chalmers, P. A. Stephens","doi":"10.1002/rse2.70012","DOIUrl":"https://doi.org/10.1002/rse2.70012","url":null,"abstract":"As camera traps have become more widely used, extracting information from images at the pace they are acquired has become challenging, resulting in backlogs that delay the communication of results and the use of data for conservation and management. To ameliorate this, artificial intelligence (AI), crowdsourcing to citizen scientists and combined approaches have surfaced as solutions. Using data from the UK mammal monitoring initiative MammalWeb, we assess the accuracies of classifications from registered citizen scientists, anonymous participants and a convolutional neural network (CNN). The engagement of anonymous volunteers was facilitated by the strategic placement of MammalWeb interfaces in a natural history museum with high footfall related to the ‘Dippy on Tour’ exhibition. The accuracy of anonymous volunteer classifications gathered through public interfaces has not been reported previously, and here we consider this form of citizen science in the context of alternative forms of data acquisition. While AI models have performed well at species identification in bespoke settings, here we report model performance on a dataset for which the model in question was not explicitly trained. We also consider combining AI output with that of human volunteers to demonstrate combined workflows that produce high accuracy predictions. We find the consensus of registered users has greater overall accuracy (97%) than the consensus from anonymous contributors (71%); AI accuracy lies in between (78%). A combined approach between registered citizen scientists and AI output provides an overall accuracy of 96%. Further, when the contributions of anonymous citizen scientists are concordant with AI output, 98% accuracy can be achieved. The generality of this last finding merits further investigation, given the potential to gather classifications much more rapidly if public displays are placed in areas of high footfall. We suggest that combined approaches to image classification are optimal when the minimisation of classification errors is desired.","PeriodicalId":21132,"journal":{"name":"Remote Sensing in Ecology and Conservation","volume":"18 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144097312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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