High-resolution land use/cover forecasts for Switzerland in the 21st century.

We present forecasts of land-use/land-cover (LULC) change for Switzerland for three time-steps in the 21 century under the representative concentration pathways 4.5 and 8.5, and at 100-m spatial and 14-class thematic resolution.

The tempo of greening in the European Alps: Spatial variations on a common theme.

The long-term increase in satellite-based proxies of vegetation cover is a well-documented response of seasonally snow-covered ecosystems to climate warming. However, observed greening trends are far from uniform, and substantial uncertainty remains concerning the underlying causes of this spatial variability. Here, we processed surface reflectance of the moderate resolution imaging spectroradiometer (MODIS) to investigate trends and drivers of changes in the annual peak values of the Normalized Difference Vegetation Index (NDVI).

Outstanding Challenges in the Transferability of Ecological Models.

Predictive models are central to many scientific disciplines and vital for informing management in a rapidly changing world. However, limited understanding of the accuracy and precision of models transferred to novel conditions (their 'transferability') undermines confidence in their predictions. Here, 50 experts identified priority knowledge gaps which, if filled, will most improve model transfers.

Do floral and niche shifts favour the establishment and persistence of newly arisen polyploids? A case study in an Alpine primrose.

Background And Aims: Polyploidization plays a key role in plant evolution. Despite the generally accepted 'minority-cytotype exclusion' theory, the specific mechanisms leading to successful establishment and persistence of new polyploids remain controversial. The majority of newly formed polyploids do not become established, because they are less common, have fewer potential mates or may not be able to compete successfully with co-occurring progenitors at lower ploidy levels.

How Do Cold-Adapted Plants Respond to Climatic Cycles? Interglacial Expansion Explains Current Distribution and Genomic Diversity in Primula farinosa L.

Understanding the effects of past climatic fluctuations on the distribution and population-size dynamics of cold-adapted species is essential for predicting their responses to ongoing global climate change. In spite of the heterogeneity of cold-adapted species, two main contrasting hypotheses have been proposed to explain their responses to Late Quaternary glacial cycles, namely, the interglacial contraction versus the interglacial expansion hypotheses. Here, we use the cold-adapted plant Primula farinosa to test two demographic models under each of the two alternative hypotheses and a fifth, null model.

Water availability predicts forest canopy height at the global scale.

The tendency of trees to grow taller with increasing water availability is common knowledge. Yet a robust, universal relationship between the spatial distribution of water availability and forest canopy height (H) is lacking. Here, we created a global water availability map by calculating an annual budget as the difference between precipitation (P) and potential evapotranspiration (PET) at a 1-km spatial resolution, and in turn correlated it with a global H map of the same resolution.

Working toward integrated models of alpine plant distribution.

Species distribution models (SDMs) have been frequently employed to forecast the response of alpine plants to global changes. Efforts to model alpine plant distribution have thus far been primarily based on a correlative approach, in which ecological processes are implicitly addressed through a statistical relationship between observed species occurrences and environmental predictors. Recent evidence, however, highlights the shortcomings of correlative SDMs, especially in alpine landscapes where plant species tend to be decoupled from atmospheric conditions in micro-topographic habitats and are particularly exposed to geomorphic disturbances.

Thermal niches are more conserved at cold than warm limits in arctic-alpine plant species.

Aim: Understanding the stability of realized niches is crucial for predicting the responses of species to climate change. One approach is to evaluate the niche differences of populations of the same species that occupy regions that are geographically disconnected. Here, we assess niche conservatism along thermal gradients for 26 plant species with a disjunct distribution between the Alps and the Arctic.

Topo-climatic microrefugia explain the persistence of a rare endemic plant in the Alps during the last 21 millennia.

Ongoing rapid climate change is predicted to cause local extinction of plant species in mountain regions. However, some plant species could have persisted during Quaternary climate oscillations without shifting their range, despite the limited evidence from fossils. Here, we tested two candidate mechanisms of persistence by comparing the macrorefugia and microrefugia (MR) hypotheses.

A greener Greenland? Climatic potential and long-term constraints on future expansions of trees and shrubs.

Warming-induced expansion of trees and shrubs into tundra vegetation will strongly impact Arctic ecosystems. Today, a small subset of the boreal woody flora found during certain Plio-Pleistocene warm periods inhabits Greenland. Whether the twenty-first century warming will induce a re-colonization of a rich woody flora depends on the roles of climate and migration limitations in shaping species ranges.

Elevational adaptation and plasticity in seedling phenology of temperate deciduous tree species.

Phenological events, such as the initiation and the end of seasonal growth, are thought to be under strong evolutionary control because of their influence on tree fitness. Although numerous studies highlighted genetic differentiation in phenology among populations from contrasting climates, it remains unclear whether local adaptation could restrict phenological plasticity in response to current warming. Seedling populations of seven deciduous tree species from high and low elevations in the Swiss Alps were investigated in eight common gardens located along two elevational gradients from 400 to 1,700 m.

Climatic niche shifts are rare among terrestrial plant invaders.

The assumption that climatic niche requirements of invasive species are conserved between their native and invaded ranges is key to predicting the risk of invasion. However, this assumption has been challenged recently by evidence of niche shifts in some species. Here, we report the first large-scale test of niche conservatism for 50 terrestrial plant invaders between Eurasia, North America, and Australia.

Variation in habitat suitability does not always relate to variation in species' plant functional traits.

Habitat suitability models, which relate species occurrences to environmental variables, are assumed to predict suitable conditions for a given species. If these models are reliable, they should relate to change in plant growth and function. In this paper, we ask the question whether habitat suitability models are able to predict variation in plant functional traits, often assumed to be a good surrogate for a species' overall health and vigour.

Niche dynamics in space and time.

Niche conservatism, the tendency of a species niche to remain unchanged over time, is often assumed when discussing, explaining or predicting biogeographical patterns. Unfortunately, there has been no basis for predicting niche dynamics over relevant timescales, from tens to a few hundreds of years. The recent application of species distribution models (SDMs) and phylogenetic methods to analysis of niche characteristics has provided insight to niche dynamics.

Prediction of plant species distributions across six millennia.

The usefulness of species distribution models (SDMs) in predicting impacts of climate change on biodiversity is difficult to assess because changes in species ranges may take decades or centuries to occur. One alternative way to evaluate the predictive ability of SDMs across time is to compare their predictions with data on past species distributions. We use data on plant distributions, fossil pollen and current and mid-Holocene climate to test the ability of SDMs to predict past climate-change impacts.