Aim Species distribution models often assume a changing climate (dynamic climate variables) but unchanged land use (static land use variables) to estimate future species distribution shifts. However, scenarios of projected land use change are available to calculate dynamic land use variables. Surprisingly, the importance of using dynamic instead of static land use variables when projecting potential future species distributions under climate change remains largely unexplored. We tested whether the joint inclusion of land use and climate change scenarios altered the projection of future species distribution compared with the classical approach assuming unchanged land use. Location  Europe Methods We used land use and climate change scenarios to estimate the future distribution of a butterfly species (Lycaena dispar) according to different perspectives of projected environmental change: (1) land use change (dynamic land use and static climate variables), (2) climate change (static land use and dynamic climate variables) and (3) global change (dynamic land use and climate variables). As the importance of land use variables is known to depend on the spatial resolution of the models, we built them across a range of resolutions (50 km, 10 km and 5 km) to examine the resolution‐dependent relevance of using dynamic instead of static variables. Results For each resolution, the projected distribution changes were unaltered when using dynamic instead of static land use variables in the models. It was mainly due to the low thematic resolution of the land use change scenarios that include only few dynamic variables. Main conclusions  Even at fine spatial resolution (5 km), the available land use change scenarios poorly represent habitat suitability for the species. Hence, they may be of limited support to estimate future species distributions. Instead of supporting the assumption of unchanged future land use, our results plea for an improvement of the thematic resolution of land use change scenarios.

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Aim: Niche-based models often ignore spatial variation in the climatic niche of a species across its occupied range and the related variation in the response to changing climate conditions. This assumption may lead to inaccurate predictions of species distribution shifts under climate change. Models have been developed to address this issue, but most of them depend upon prior knowledge on evolutionary lineages, phenotypic traits or ecological processes underlying local adaptation or adaptive plasticity. As such information is often lacking, these models are not frequently used to predict distribution shifts for many species. This limits our ability to explore general patterns of change across species.Innovation: Here, we propose a modelling framework that can be applied across a large sample of species to assess their distribution shifts under future climate while exploring the effect of intraspecific spatial variation in the response to climate conditions. The proposed approach does not require a detailed understanding of the processes underlying such variation. The geographical distribution of a species is split into spatial subsets along the gradient of occupied climate conditions. These subsets are considered as proxies for intraspecific spatial niche variation. Local models are built with each subset and their predictions are assembled across the study area | 591 MARTIN eT Al.

Poleward range shifts under climate change involve the colonization of new sites and hence the foundation of new populations at the expanding edge. We studied oviposition site selection in a butterfly under range expansion (Lycaena dispar), a key process for the establishment of new populations. We described and compared the microhabitats used by the species for egg laying with those available across the study sites both in edge and in core populations. We carried out an ecological niche factor analysis (ENFA) to estimate (1) the variety of microhabitats used by the butterfly for egg laying (tolerance) and (2) the extent to which these selected microhabitats deviated from those available (marginality). Microhabitat availability was similar in edge and core populations. Ambient temperature recorded at the site level above the vegetation was on average lower at core populations. In contrast with what is often assumed, edge populations did not have narrower microhabitat use compared to core populations. Females in edge populations even showed a higher degree of generalism: They laid eggs under a wider range of microhabitats. We suggest that this pattern could be related to an overrepresentation of fast deciding personalities in edge populations. We also showed that the thermal time window for active female behavior was reduced in edge populations, which could significantly decrease the time budget for oviposition and decrease the threshold of acceptance during microhabitat selection for oviposition in recently established populations.