Climate change impacts and vulnerability in Europe 2016

Climate change impacts on environmental systems
4.4.4 Distribution shifts of plant and animal species
Key messages
• Observed climate change is having significant impacts on the distribution of European flora and fauna, with distribution
changes of several hundred kilometres projected over the 21st century. These impacts include northwards and uphill
range shifts, as well as local and regional extinctions of species.
• The migration of many species is lagging behind the changes in climate owing to intrinsic limitations, habitat use and
fragmentation, and other obstacles, suggesting that they are unable to keep pace with the speed of climate change.
Observed and modelled differences between actual and required migration rates may lead to a progressive decline in
European biodiversity.
• Climate change is likely to exacerbate the problem of invasive species in Europe. As climatic conditions change, some
locations may become more favourable to previously harmless alien species, which then become invasive and have
negative impacts on their new environments.
• Climate change is affecting the interaction of species that depend on each other for food or other reasons. It can disrupt
established interactions but also generate novel ones.
Relevance
Climate change affects ecosystems in complex ways.
Many sites will experience a change in the composition
and abundance of species. This change does not
necessarily translate into species loss, but generalist
species appear to be favoured over specialists.
The composition of many plant communities is
changing, often to such an extent that completely
new assemblages are appearing (Urban et al., 2012).
The extinction risk is particularly large at the trailing
edge (i.e. southern or lower altitudinal range margins)
of a species (Dirnböck et al., 2011). The ecological
implications of these changes and their effects on
the provision of ecosystems services are difficult to
assess and quantify. However, it is clear that climate
change is an important threat for long-term biodiversity
conservation. It threatens the ability of meeting the
EU policy target to halt biodiversity loss by 2020. In
the longer term, the favourable status of Natura 2000
sites is also in danger (Thuiller et al., 2011; Hickler et al.,
2012). The negative effects of climate change not only
are having an impact on habitats that already have an
unfavourable conservation status, but also are likely
to cause changes in habitats that presently have a
favourable conservation status (EC, 2013b).
Shifts in the distribution of plant and animal species
can have consequences for agriculture (crops and
livestock), forestry, human health, biodiversity and its
conservation, and ecosystem functions and services
(see Section 4.5). The distribution of many animal
species will be particularly affected by climate change
if habitat fragmentation impedes their movement
to more suitable climatic conditions. Northwards
and uphill movements are taking place two to three
times faster than previously reported (Chen et al.,
2011). An increased extinction risk compared with
previous findings is predicted, and is supported by
observed responses to climate change (Maclean and
Wilson, 2011). A 'biotic homogenisation' of specific
ecological communities of European flora and fauna
(i.e. losing regional uniqueness and characteristics) is
projected (Davey et al., 2012). Looking at the Natura
2000 terrestrial species, amphibians are considered
to be most vulnerable to climate change. For many
invertebrates (with the exception of butterflies), not
much is known about their response to climate change,
as there is limited knowledge about their ecology or their
present distribution (EC, 2013b).
The impacts of climate change on a single species can
lead to disruptions or alterations of currently existing
species interactions such as competition, herbivory,
predation, parasitism, pollination and symbiosis. These
interactions are affected because different species
adapt their phenology (i.e. the timing of annual events)
and their distributional range differently in response to
climate change (Kovats et al., 2014; Settele et al., 2014).
Species interactions can further be disrupted by invasive
species introduced as a result of human interference.
Climate change can also affect disturbance regimes,
such as wildfires and storms. Biodiversity is increasingly
acknowledged as providing indispensable ecosystem
services, such as increasing the resistance of ecosystem
productivity to climate extremes (Isbell et al., 2015).
Therefore, the 'EU Biodiversity Strategy to 2020' regards
biodiversity as 'our collective life insurance' (EC, 2011).
Climate change, impacts and vulnerability in Europe 2016 | An indicator-based report
167