TABLE 1.

Effects of global changes drivers on the outcome of species interaction through their effect on niche and fitness differences.

Global change driver	Effect on niche differences	Effect on fitness differences	Examples
Climate change	Increased climate variability can increase niche differentiation by promoting species with contrasted phenotypes.	New climate regimes possibly change the species hierarchy according their competitive ability. Dominant species become less competitive and subordinate species increase their dominance.	Sherry et al. (2007), Willis et al. (2008), Angert et al. (2009), Mariotte et al. (2013)
Nutrient pollution	Increase in nutrients (N, P) is reducing environmental heterogeneity and thus the chances of species to exploit resources from different niches.	A few species are benefiting from these more homogeneous environments leading to a few species outcompeting the rest. Other species are excluded because they cannot tolerate the new environmental conditions.	Reich et al. (2001), Stevens et al. (2004), Wookey et al. (2009)
Land use change	Novel ecosystems and intense landscape transformations is homogenizing the environment and reducing niche differences within communities. Among communities, land conversion is producing contrasting novel habitats increasing niche differentiation among species at large geographical scales.	Similar effects to nutrient application to agricultural systems. The competitive ability of a few species is dramatically increased, while other species are not able to survive. This reduces the diversity among and within communities.	Hobbs et al. (2006)
Biological invasions	Exotic species with contrasted phenotypes are able to exploit different resources increasing niche differentiation with respect to the resident community. Exotic species with similar phenotypes would reduce niche differentiation and increase niche overlap.	Although most of the introduced species fail to survive and invade because they cannot tolerate the new environmental conditions where they are introduced, successful invaders tend to possess traits that maximize competitive ability for a given quantity of resources.	Strauss et al. (2006), Funk et al. (2008), MacDougall et al. (2009), van Kleunen et al. (2010), Fridley (2012), Godoy and Levine (2014)