Changes in vegetation phenology related to global warming are having alarming effects on the life history traits of many herbivore species.Such changes are particularly critical in alpine ecosystems,where strong clima...Changes in vegetation phenology related to global warming are having alarming effects on the life history traits of many herbivore species.Such changes are particularly critical in alpine ecosystems,where strong climate limitations on plant growth make seasonal synchronization imperative for the growth,reproduction and survival of herbivores.However,despite the pivotal role of resource-use strategies on the performances of such species,few studies have explicitly assessed the mechanistic impact of climate change on their diets.We aimed to fill this gap by studying the effect of spring onset on the dietary composition and quality of a medium-size alpine herbivore while considering density-dependent processes and age-and sex-specific differences in foraging behavior.Using an exceptional,long-term(24 years)direct individual-based dietary monitoring of a Pyrenean chamois population(Rupicapra pyrenaica pyrenaica),we showed that ongoing earlier onsets of spring are leading to an earlier access to high-quality forage and therefore a higher diet quality at a fixed date,without apparent changes in diet composition.We also showed that at high densities,intraspecific competition reduced diet quality by driving animals to feed more on woody plants and less on nutritious forbs and graminoids.By assessing the mechanistic effects of global warming on the dietary patterns of species at the center of trophic networks,this study is an essential step for predictive models aiming at understanding the ongoing ecosystem consequences of the global climatic crisis.展开更多
基金funded by the research partnership program“Approche Intégrée de la Démographie des Populations d’Isard”(N°2014/08/6171)between the Office Français de la Biodiversité(formerly Office National de la Chasse et de la Faune Sauvage)the Servei d’Ecopatologia de la Fauna Salvatge(SEFaS).Johan Espunyes acknowledges a pre-doctoral grant from the Government of Andorra(ATC015 AND 2015/2016,2016/2017,and 2017/2018)Emmanuel Serrano was funded by the Spanish Ministerio de Economía y Competitividad(Mineco)through a Ramon y Cajal agreement(RYC-2016-21120).
文摘Changes in vegetation phenology related to global warming are having alarming effects on the life history traits of many herbivore species.Such changes are particularly critical in alpine ecosystems,where strong climate limitations on plant growth make seasonal synchronization imperative for the growth,reproduction and survival of herbivores.However,despite the pivotal role of resource-use strategies on the performances of such species,few studies have explicitly assessed the mechanistic impact of climate change on their diets.We aimed to fill this gap by studying the effect of spring onset on the dietary composition and quality of a medium-size alpine herbivore while considering density-dependent processes and age-and sex-specific differences in foraging behavior.Using an exceptional,long-term(24 years)direct individual-based dietary monitoring of a Pyrenean chamois population(Rupicapra pyrenaica pyrenaica),we showed that ongoing earlier onsets of spring are leading to an earlier access to high-quality forage and therefore a higher diet quality at a fixed date,without apparent changes in diet composition.We also showed that at high densities,intraspecific competition reduced diet quality by driving animals to feed more on woody plants and less on nutritious forbs and graminoids.By assessing the mechanistic effects of global warming on the dietary patterns of species at the center of trophic networks,this study is an essential step for predictive models aiming at understanding the ongoing ecosystem consequences of the global climatic crisis.
