The Response of Soil CO2 Fluxes to Progressively Excluding Vertebrate and Invertebrate Herbivores Depends on Ecosystem Type

Grasslands support large populations of herbivores and store up to 30% of the world's soil carbon (C). Thus, herbivores likely play an important role in the global C cycle. However, most studies on how herbivory impacts the largest source of C released from grassland soils—soil carbon dioxide (CO2) emissions—only considered the role of large ungulates. This ignores all other vertebrate and invertebrate herbivores and their collective effects on ecosystem properties. We progressively excluded large, medium, and small vertebrates and invertebrates from two subalpine grasslands (productive, heavily grazed short-grass; less productive, lightly grazed tall-grass) using size-selective fences, assessed the impact on soil CO2 emissions and related biotic and abiotic variables. Exclusion resulted in significant changes in soil CO2 emissions in both vegetation types. Short-grass soil CO2 emissions progressively increased when large and medium mammals were excluded. However, no difference was detected among plots were all or no herbivores grazed. In contrast, tall-grass soil CO2 emissions were not affected by mammal exclusion, but excluding all herbivores lead to reduced emissions. Soil micro-climatic parameters best predicted the patterns of soil CO2 emissions in short-grass vegetation, whereas root biomass was the best predictor of CO2 release in tall-grass vegetation. Our results showed that diverse herbivore communities affect soil respiration differently than assumed from previous studies that only excluded large ungulates. Such information is important if we are to understand how changes in herbivore species composition—as could happen through altered management practices, extinction or invasion—impact grassland C storage and releas

Green-up selection by red deer in heterogeneous, human-dominated landscapes of Central Europe

The forage maturation hypothesis (FMH) assumes that herbivores cope with the trade-off between digestibility and biomass in forage by selecting vegetation at intermediate growth. The green wave hypothesis (GWH) extends the FMH to suggest how spatiotemporal heterogeneity in plant quality shapes migratory movements of herbivores. Growing empirical support for these hypotheses mainly comes from studies in vast landscapes with large-scale habitat heterogeneity. It is unclear, however, to what extent ungulates surf green waves in human-altered landscapes with small-scale heterogeneity in terms of land use and topography. We used plant phenological proxies derived from Sentinel 2 satellite data to analyze the habitat selection of 93 collared red deer (Cervus elaphus) in montane and alpine habitats. Using a step selection analysis, we investigated how plant phenology, that is, the instantaneous rate of green-up (IRG) and normalized difference vegetation index (NDVI), and a set of variables describing topography and human presence influenced red deer resource selection in open habitats. We learned that red deer selected areas with high biomass at green-up and avoided habitats with possible exposure to human activity. Additionally, landscape structure and topography strongly influenced spatial behavior of red deer. We further compared cumulative access to high-quality forage across migrant strategies and found migrants gained better access than residents. Many migratory individuals surfed the green wave, and their surfing behavior, however, became less pronounced with decreasing distance to settlements. Within the constraints of topography and human land use, red deer track spring green-up on a fine spatiotemporal scale and follow the green wave across landscapes in migration movements. Thus, they benefit from high-quality forage even in human-dominated landscapes with small-scale heterogeneity and vegetation emerging in a heterogenic, dynamic mosaic

Identifying the environmental drivers of corridors and predicting connectivity between seasonal ranges in multiple populations of Alpine ibex (Capra ibex) as tools for conserving migration

Aim Seasonal migrations, such as those of ungulates, are particularly threatened by habitat transformations and fragmentation, climate and other environmental changes caused by anthropogenic activities. Mountain ungulate migrations are neglected because they are relatively short, although traversing heterogeneous altitudinal gradients particularly exposed to anthropogenic threats. Detecting migration routes of these species and understanding their drivers are therefore of primary importance to predict connectivity and preserve ecosystem functions and services. The populations of Alpine ibex Capra ibex have all been reintroduced from the last remnant source population. Despite a general increase in abundance and overall distribution range, ibex populations are mostly disconnected but display intra-population migrations. Therefore, its conservation is strictly linked to the interplay between external threats and related behavioural responses, including space use and migration. Location Austria, France, Italy and Switzerland. Methods By using 337 migratory tracks from 425 GPS-collared individuals from 15 Alpine ibex populations distributed across their entire range, we (i) identified the environmental drivers of movement corridors in both spring and autumn and (ii) compared the ability of a connectivity modelling algorithm to predict migratory movements between seasonal ranges of the 15 populations, using either population-specific or multipopulation datasets, and three validation procedures. Results Steep, south-facing, snow-free slopes were selected while high elevation changes were avoided. This revealed the importance of favourable resources and an attempt to limit energy expenditures and perceived predation risk. The abilities of the modelling methods we compared to predict migratory connectivity from the results of those movement analyses were similar. Main Conclusions The trade-off between energy expenditure, food and cover was the major driver of migration routes and was overall consistent among populations. Based on these findings, we provided useful connectivity models to inform conservation of Alpine ibex and its habitats, and a framework for future research investigating connectivity in migratory specie

Viele Köche retten den Brei: Erfolgsfaktoren im Wildlifemanagement / Beaucoup de cuisiniers sauvent le potage : Facteurs de réussite dans la gestion de la faune sauvage

Zusammenfassung: Der Not gehorchend hat sich Wildlifemanagement sehr gewandelt. Lange Zeit dominierten okologische Ansätze die Disziplin. Dann wurde deutlich, dass aile Aufgaben auch eine soziologische und ôko- nomische Dimension auszeichnet, oft auch eine politische. Wirksame Problemlosungsstrategien miissen daher problemgerecht sein. Im Wildlifemanagement haben sich die Identifikation und Beteiligung von Interessens- gruppen an der Zielfindung und an den Losungsansätzen als besonders wichtig gezeigt.Abstract: Many cooks save the broth: factors for a successful Wildlifemanagement. Bowing to necessity, wildlife management has changed considerably. For many years this discipline was largely dominated by ecological considerations. It became clear, however, that socialogical and economical factors also had a role to play, as well as politics. Effective problem-solving strategies must be adapted to the problem in question. In wildlife management the importance of identifying and involving different groups of interest in establishing aims and providing a basis for solving problems has been clearly shown.Resume : Beaucoup de cuisiniers sauvent le potage : Facteurs de réussite dans la gestion de la faune sauvage. Obéissant à l'urgence, l'approche de la gestion de la faune sauvage s'est considérablement modifiée ces dernières années. Au début, les approches écologiques ont longtemps dominé la discipline, mais par la suite, il est devenu évident que cette tâche comportait également des dimensions sociologiques et économiques, mais également souvent, une dimension politique. Les stratégies de résolution de problèmes efficaces doivent donc être équitables pour tous les groupes d'intérêt. Dans la gestion de la faune sauvage, l'identification et la participation des groupes d'intérêts se sont montrées particulièrement importantes pour la recherche d'objectifs et de solutions communes.Filli Flurin, Schröder Wolfgang. Viele Köche retten den Brei: Erfolgsfaktoren im Wildlifemanagement / Beaucoup de cuisiniers sauvent le potage : Facteurs de réussite dans la gestion de la faune sauvage. In: Revue de géographie alpine, tome 90, n°2, 2002. pp. 117-126

The weather dictates the rhythms: Alpine chamois activity is well adapted to ecological conditions

Activity rhythms play an important role in the ecological relations of a species and form part of its evolutionary adaptation. Such rhythms are strongly synchronised with the annual cyclic changes by environmental stimuli, the so-called zeitgebers. Animals’ reliance on environmental stimuli is highly species-specific and allows behavioural adjustments to be made in preparation for the conditions expected in each season. We investigated daily and annual activity rhythms of Alpine chamois (Rupicapra rupicapra) by analysing high-resolution data of animals monitored with GPS collars. This first detailed field study of chamois activity showed that this species exhibited clear daily and annual activity rhythms entrained to the light-dark cycle. Chamois were more active during spring-summer and less active during winter, likely in response to the variation in the availability of food resources: both sexes appeared to maximise energy intake during the season offering the highest amount of food resources to compensate for poor food supply during winter. Daily activity was influenced by the climatic factors considered. We showed a negative correlation between daily activity and adverse climatic conditions (i.e. precipitation and, during winter, snow depth). As activity was strongly influenced by the interplay between temperature and wind throughout the year and by radiation and wind in winter, we conjectured that it was critically dependent upon animals’ thermal balance. In conclusion, our study highlighted that chamois is well adapted to the Alpine environment and seasonality but also raised questions about its ability to adapt to future climate change. Significance statement: In this study, we investigated the effects of ecological factors on Alpine chamois activity. Thanks to radio collars with accelerometers, we obtained highly detailed information on activity levels of wild animals. We found that chamois were more active during spring-summer (i.e. the seasons with the highest quality and quantity of food) and less active during winter. Our results showed that chamois activity was strongly influenced by such climatic factors as temperature, precipitation and wind speed. In winter time, chamois activity increased during the days with high solar radiation and decreased with high snow depth. Given their wide distribution in the Alps, chamois can be considered as a sentinel species of Alpine habitats. Thus, our results on the current relationship between climate and chamois behaviour may shed light on the animals’ ability to track and adapt to climate change

Rothirsche in der Val Foraz, Komplexe Karten machen Veränderungen sichtbar

Die saisonalen Wanderungen der Rothirsche sind gut erforscht und haben sich in den letzten Jahren nicht grundsätzlich verändert (Seite 148). Doch nutzen die Hirsche über zwei Jahrzehnte ein Gebiet immer gleich? Verändert sich der Tagesgang der Raumnutzung mit der Zeit? Aus der Val Foraz liegt ein Datensatz vor, der den Tagesgang des Raumverhaltens der Rothirsche langfristig dokumentiert. Die Herausforderung liegt oft nicht nur in der Erhebung, sondern auch in der Visualisierung und Auswertung der Daten. 2012 entstand eine komplexe Karte, welche die Veränderung der Raumnutzung über die Zeit sichtbar machen soll

Multi‐event capture‐recapture analysis in Alpine chamois reveals contrasting responses to interspecific competition, within and between populations

International audienc