Signe Normand

Signe Normand


Research Focus & Metrics

Academic Career Length

22Years (2005-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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12 June 2012 in Biological Reviews
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Journal Article
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MWMary Susanne Wisz
Mary Susanne Wisz
JPJulien Pottier
Julien Pottier
WKW. Daniel Kissling
W. Daniel Kissling
LPLoïc Pellissier
Loïc Pellissier
JLJonathan Lenoir
Jonathan Lenoir
Jens-Christian SvenningJens-Christian Svenning
Jens-Christian Svenning
Predicting which species will occur together in the future, and where, remains one of the greatest challenges in ecology, and requires a sound understanding of how the abiotic and biotic environments interact with dispersal processes and history across scales. Biotic interactions and their dynamics influence species' relationships to climate, and this also has important implications for predicting future distributions of species. It is already well accepted that biotic interactions shape species' spatial distributions at local spatial extents, but the role of these interactions beyond local extents (e.g. 10 km2 to global extents) are usually dismissed as unimportant. In this review we consolidate evidence for how biotic interactions shape species distributions beyond local extents and review methods for integrating biotic interactions into species distribution modelling tools. Drawing upon evidence from contemporary and palaeoecological studies of individual species ranges, functional groups, and species richness patterns, we show that biotic interactions have clearly left their mark on species distributions and realised assemblages of species across all spatial extents. We demonstrate this with examples from within and across trophic groups. A range of species distribution modelling tools is available to quantify species environmental relationships and predict species occurrence, such as: (i) integrating pairwise dependencies, (ii) using integrative predictors, and (iii) hybridising species distribution models (SDMs) with dynamic models. These methods have typically only been applied to interacting pairs of species at a single time, require a priori ecological knowledge about which species interact, and due to data paucity must assume that biotic interactions are constant in space and time. To better inform the future development of these models across spatial scales, we call for accelerated collection of spatially and temporally explicit species data. Ideally, these data should be sampled to reflect variation in the underlying environment across large spatial extents, and at fine spatial resolution. Simplified ecosystems where there are relatively few interacting species and sometimes a wealth of existing ecosystem monitoring data (e.g. arctic, alpine or island habitats) offer settings where the development of modelling tools that account for biotic interactions may be less difficult than elsewhere.

31 January 2020 in Nature Climate Change
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Journal Article
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IMIsla H. Myers-Smith
Isla H. Myers-Smith
JKJeffrey Kerby
Jeffrey Kerby
GPGareth K. Phoenix
Gareth K. Phoenix
JBJarle W. Bjerke
Jarle W. Bjerke
HEHoward Epstein
Howard Epstein
SWSonja Wipf
Sonja Wipf

24 December 2010 in Global Change Biology
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Journal Article
Closed access
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RERobin Engler
Robin Engler
CRChristophe F. Randin
Christophe F. Randin
WTWilfried Thuiller
Wilfried Thuiller
SDStefan Dullinger
Stefan Dullinger
NZNiklaus Zimmermann
Niklaus Zimmermann
AGAntoine Guisan
Antoine Guisan

16 September 2014 in Ecography
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Journal Article
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CMCory Merow
Cory Merow
MSMathew J. Smith
Mathew J. Smith
TEThomas C. Edwards
Thomas C. Edwards
AGAntoine Guisan
Antoine Guisan
SMSean M. McMahon
Sean M. McMahon
JEJane Elith
Jane Elith
Species distribution models (SDMs) are widely used to explain and predict species ranges and environmental niches. They are most commonly constructed by inferring species' occurrence–environment relationships using statistical and machine‐learning methods. The variety of methods that can be used to construct SDMs (e.g. generalized linear/additive models, tree‐based models, maximum entropy, etc.), and the variety of ways that such models can be implemented, permits substantial flexibility in SDM complexity. Building models with an appropriate amount of complexity for the study objectives is critical for robust inference. We characterize complexity as the shape of the inferred occurrence–environment relationships and the number of parameters used to describe them, and search for insights into whether additional complexity is informative or superfluous. By building ‘under fit’ models, having insufficient flexibility to describe observed occurrence–environment relationships, we risk misunderstanding the factors shaping species distributions. By building ‘over fit’ models, with excessive flexibility, we risk inadvertently ascribing pattern to noise or building opaque models. However, model selection can be challenging, especially when comparing models constructed under different modeling approaches. Here we argue for a more pragmatic approach: researchers should constrain the complexity of their models based on study objective, attributes of the data, and an understanding of how these interact with the underlying biological processes. We discuss guidelines for balancing under fitting with over fitting and consequently how complexity affects decisions made during model building. Although some generalities are possible, our discussion reflects differences in opinions that favor simpler versus more complex models. We conclude that combining insights from both simple and complex SDM building approaches best advances our knowledge of current and future species ranges.

4 May 2009 in Global Change Biology
Verified
Journal Article
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CRChristophe F. Randin
Christophe F. Randin
RERobin Engler
Robin Engler
SNSigne Normand
Signe Normand
MZMassimiliano Zappa
Massimiliano Zappa
NZNiklaus Zimmermann
Niklaus Zimmermann
AGAntoine Guisan
Antoine Guisan

11 February 2022 in Global Change Biology
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Journal Article
Open access
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JLJonas Lembrechts
Jonas Lembrechts
JHJohan van Den Hoogen
Johan van Den Hoogen
JAJuha Aalto
Juha Aalto
MAMichael B. Ashcroft
Michael B. Ashcroft
PFPieter De Frenne
Pieter De Frenne
JLJonathan Lenoir
Jonathan Lenoir
Research in global change ecology relies heavily on global climatic grids derived from estimates of air temperature in open areas at around 2 m above the ground. These climatic grids do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur and most terrestrial species reside. Here, we provide global maps of soil temperature and bioclimatic variables at a 1‐km2resolution for 0–5 and 5–15 cm soil depth. These maps were created by calculating the difference (i.e. offset) between in situ soil temperature measurements, based on time series from over 1200 1‐km2pixels (summarized from 8519 unique temperature sensors) across all the world's major terrestrial biomes, and coarse‐grained air temperature estimates from ERA5‐Land (an atmospheric reanalysis by the European Centre for Medium‐Range Weather Forecasts). We show that mean annual soil temperature differs markedly from the corresponding gridded air temperature, by up to 10°C (mean = 3.0 ± 2.1°C), with substantial variation across biomes and seasons. Over the year, soils in cold and/or dry biomes are substantially warmer (+3.6 ± 2.3°C) than gridded air temperature, whereas soils in warm and humid environments are on average slightly cooler (−0.7 ± 2.3°C). The observed substantial and biome‐specific offsets emphasize that the projected impacts of climate and climate change on near‐surface biodiversity and ecosystem functioning are inaccurately assessed when air rather than soil temperature is used, especially in cold environments. The global soil‐related bioclimatic variables provided here are an important step forward for any application in ecology and related disciplines. Nevertheless, we highlight the need to fill remaining geographic gaps by collecting more in situ measurements of microclimate conditions to further enhance the spatiotemporal resolution of global soil temperature products for ecological applications.