Long-term monitoring of mammal communities in the Peneda-Gerês National Park using camera-trap data.

Background: In the past decades, agricultural land abandonment and declining land-use intensity became common, especially in the Mediterranean countries of southern Europe. In some areas, this development opened up possibilities for rewilding and the recolonisation or expansion of large mammal populations. Yet, in some instances, co-occurrence of wild mammals and free-ranging domestic herbivores might lead to potential conflicts. It is, therefore, necessary to study the ecological interactions between wild and domestic mammal species to understand the effects of land abandonment and rewilding on biodiversity and ecosystem services. Camera traps are an effective tool for studying species interactions and occupancy dynamics as they allow for long-term monitoring with minimal interference. We conducted a long-term monitoring programme with camera traps in the Peneda-Gerês National Park in northern Portugal. The area has undergone substantial land-use changes following the abandonment of agricultural areas in the past 60 years. While agro-pastoral activities, especially the breeding of free-ranging horses and cattle, are still common in the area, the intensity of these activities has decreased significantly, promoting natural succession and an increase or return of several large mammal species in recent years. Overall, our project aims at: (1) assessing the population trends of the medium and large sized mammals in the area over time; (2) analysing the effects of passive rewilding on occurrence, abundance and behaviour; and (3) understanding potential interactions or conflicts between wild and domestic herbivores. In this publication, we present results of a primary occupancy analysis between 2015 and 2020, as well as a comparison between occupancy and density estimates for 2019. New information: Our publication provides a dataset from long-term camera-trap monitoring in the Peneda-Gerês National Park between 2015 and 2021. We established a 16 km² grid of 64 cameras deployed yearly during the summer months. Together with this publication, we publish the data and images collected between 2015 and 2021, using both the Camtrap DP standard and the GBIF Darwin Event Core. We obtained a total of 934,810 pictures on 41,234 trap nights. The pictures were automatically grouped into sequences with each sequence representing a distinct occurrence event, resulting in 80,191 occurrences. Out of those, 14,442 contained observations of a species, while the remaining were either blank or the species was not identifiable. We only obtained the information whether a species was present or absent on a picture, disregarding the number of individuals. Most observations were of domestic cattle (Bostaurus) and horses (Equuscaballus), followed by European roe deer (Capreoluscapreolus) and wild boar (Susscrofa). Further observations include red fox (Vulpesvulpes), gray wolf (Canislupus), Eurasian badger (Melesmeles), stone marten (Martesfoina), common genet (Genettagenetta), Iberian ibex (Caprapyrenaica) and red deer (Cervuselaphus). We estimated occupancy and densities for the most common species. The project is on-going and additional data will be included in the future. The dataset is freely available for ecological analysis, but also for training machine-learning systems in automated image classification as all pictures have been manually classified.

Rewilding complex ecosystems.

The practice of rewilding has been both promoted and criticized in recent years. Benefits include flexibility to react to environmental change and the promotion of opportunities for society to reconnect with nature. Criticisms include the lack of a clear conceptualization of rewilding, insufficient knowledge about possible outcomes, and the perception that rewilding excludes people from landscapes. Here, we present a framework for rewilding that addresses these concerns. We suggest that rewilding efforts should target trophic complexity, natural disturbances, and dispersal as interacting processes that can improve ecosystem resilience and maintain biodiversity. We propose a structured approach to rewilding projects that includes assessment of the contributions of nature to people and the social-ecological constraints on restoration.

Identifying key needs for the integration of social-ecological outcomes in arctic wildlife monitoring.

For effective monitoring in social-ecological systems to meet needs for biodiversity, science, and humans, desired outcomes must be clearly defined and routes from direct to derived outcomes understood. The Arctic is undergoing rapid climatic, ecological, social, and economic changes and requires effective wildlife monitoring to meet diverse stakeholder needs. To identify stakeholder priorities concerning desired outcomes of arctic wildlife monitoring, we conducted in-depth interviews with 29 arctic scientists, policy and decision makers, and representatives of indigenous organizations and nongovernmental organizations. Using qualitative content analysis, we identified and defined desired outcomes and documented links between outcomes. Using network analysis, we investigated the structure of perceived links between desired outcomes. We identified 18 desired outcomes from monitoring and classified them as either driven by monitoring information, monitoring process, or a combination of both. Highly cited outcomes were make decisions, conserve, detect change, disseminate, and secure food. These reflect key foci of arctic monitoring. Infrequently cited outcomes (e.g., govern) were emerging themes. Three modules comprised our outcome network. The modularity highlighted the low strength of perceived links between outcomes that were primarily information driven or more derived (e.g., detect change, make decisions, conserve, or secure food) and outcomes that were primarily process driven or more derived (e.g., cooperate, learn, educate). The outcomes expand monitoring community and disseminate created connections between these modules. Key desired outcomes are widely applicable to social-ecological systems within and outside the Arctic, particularly those with wildlife subsistence economies. Attributes and motivations associated with outcomes can guide development of integrated monitoring goals for biodiversity conservation and human needs. Our results demonstrated the disconnect between information- and process-driven goals and how expansion of the monitoring community and improved integration of monitoring stakeholders will help connect information- and process-derived outcomes for effective ecosystem stewardship.

Identificación de las Necesidades Clave para la Integración de Resultados Socio-Ecológicos en el Monitoreo de Fauna en el Ártico Resumen Para que el monitoreo efectivo en los sistemas socio-ecológicos cumpla con las necesidades de la biodiversidad, la ciencia, y los humanos, se deben definir claramente los resultados deseados y se deben entender las rutas que se toman de los resultados directos hacia los resultados derivados. El Ártico está sufriendo rápidamente cambios climáticos, ecológicos, y económicos, y requiere de un monitoreo efectivo de fauna para cumplir con las necesidades de diversos accionistas. Realizamos entrevistas a profundidad con 29 científicos del Ártico, responsables de decisiones y políticas, y representativos de organizaciones indígenas y organizaciones no gubernamentales para identificar las prioridades de los accionistas con respecto a los resultados deseados del monitoreo de fauna ártica. Mediante un análisis cualitativo de contenido identificamos y definimos los resultados deseados y documentamos las conexiones entre los resultados. Con un análisis de redes investigamos la estructura de las conexiones percibidas y las clasificamos como causadas por el monitoreo de información, el monitoreo del proceso, o una combinación de ambos. Los resultados con un mayor número de menciones fueron tomar decisiones, conservar, detectar cambios, diseminar, y asegurar alimento. Estos reflejan los enfoques más importantes del monitoreo en el Ártico. Los resultados con poca frecuencia en las menciones (p. ej.: regular) correspondían a temas emergentes. Nuestra red de resultados estuvo compuesta por tres módulos. La modularidad resaltó la poca fuerza de las conexiones percibidas entre los resultados que fueron causados principalmente por la información o que estuvieron más derivados (p. ej.: detectar el cambio, tomar decisiones, conservar o asegurar alimento) y los resultados que fueron causados principalmente por el proceso o que estuvieron más derivados (p. ej.: cooperar, aprender, educar). Los resultados expanden la comunidad monitora y diseminan las conexiones creadas entre estos módulos. Los resultados clave deseados se pueden aplicar extensamente a los sistemas socio-ecológicos dentro y fuera del Ártico, particularmente aquellos con economías de sustento basadas en la fauna. Los atributos y motivaciones asociados con los resultados pueden guiar el desarrollo de los objetivos integrados de monitoreo para la conservación de la biodiversidad y las necesidades humanas. Nuestros resultados demostraron la desconexión entre los objetivos conducidos por la información y aquellos conducidos por el proceso y cómo la expansión de la comunidad monitora y una mejor integración de los accionistas monitores ayudarán a conectar los resultados derivados de la información y derivados del proceso para una administración efectiva del ecosistema.

Wildlife species benefitting from a greener Arctic are most sensitive to shrub cover at leading range edges.

Widespread expansion of shrubs is occurring across the Arctic. Shrub expansion will substantially alter arctic wildlife habitats. Identifying which wildlife species are most affected by shrubification is central to predicting future arctic community composition. Through meta-analysis, we synthesized the published evidence for effects of canopy-forming shrubs on birds and mammals in the Arctic and Subarctic. We examined variation in species behaviour, distribution and population dynamics in birds and mammals in response to shrub cover (including shrub cover indicators such as shrub occurrence, extent, density and height). We also assessed the degree of heterogeneity in wildlife responses to shrub cover and synthesized the remaining literature that did not fit the criteria for our quantitative meta-analyses. Species from higher green vegetation biomass habitats (high Normalized Difference Vegetation Index, NDVI, across their distribution) were more likely to respond positively to shrub cover, demonstrating the potential for species to expand from boreal to arctic habitats under shrubification. Wildlife populations located in the lowest vegetation biomass (low NDVI) areas of their species' range had the greatest proportion of positive responses to shrub cover, highlighting how increases in performance at leading edges of invaders distributions may be particularly rapid. This demonstrates the need to study species at these leading edges to accurately predict expansion potential. Arctic specialists were poorly represented across studies (limited to 5 bird and 0 mammal species), this knowledge gap potentially explains the few reported negative effects of shrub cover (3 of 29 species). Species responses to shrub cover showed substantial heterogeneity and varied among sites and years in all studies with sufficient replication to detect such variation. Our study highlights the importance of responses at species range edges in determining outcomes of shrubification for arctic birds and mammals and the need for greater examination of potential wildlife losers under shrubification.

Phenological mismatch with abiotic conditions implications for flowering in Arctic plants.

Although many studies have examined the phenological mismatches between interacting organisms, few have addressed the potential for mismatches between phenology and seasonal weather conditions. In the Arctic, rapid phenological changes in many taxa are occurring in association with earlier snowmelt. The timing of snowmelt is jointly affected by the size of the late winter snowpack and the temperature during the spring thaw. Increased winter snowpack results in delayed snowmelt, whereas higher air temperatures and faster snowmelt advance the timing of snowmelt. Where interannual variation in snowpack is substantial, changes in the timing of snowmelt can be largely uncoupled from changes in air temperature. Using detailed, long-term data on the flowering phenology of four arctic plant species from Zackenberg, Greenland, we investigate whether there is a phenological component to the temperature conditions experienced prior to and during flowering. In particular, we assess the role of timing of flowering in determining pre-flowering exposure to freezing temperatures and to the temperatures-experienced prior to flowering. We then examine the implications of flowering phenology for flower abundance. Earlier snowmelt resulted in greater exposure to freezing conditions, suggesting an increased potential for a mismatch between the timing of flowering and seasonal weather conditions and an increased potential for negative consequences, such as freezing 'damage. We also found a parabolic relationship between the timing of flowering and the temperature experienced during flowering after taking interannual temperature effects into account. If timing of flowering advances to a cooler period of the growing season, this may moderate the effects of a general warming trend across years. Flower abundance was quadratically associated with the timing of flowering, such that both early and late flowering led to lower flower abundance than did intermediate flowering. Our results indicate that shifting the timing of flowering affects the temperature experienced during flower development and flowering beyond that imposed by interannual variations in climate. We also found that phenological timing may affect flower abundance, and hence, fitness. These findings suggest that plant population responses to future climate change will be shaped not only by extrinsic climate forcing, but also by species' phenological responses.