International Day of Climate Action

In 2009,, the international environmental organisation, designated 24 October as the International Day of Climate Action. This was first organised to influence the delegates attending the annual Conference of the Parties in Copenhagen (COP15). There is no COP this year, but that does not mean we can afford to forget about the importance of climate action.

In this post, we hear from some of the Journal of Ecology Associate Editors about how climate change affects their areas of interest.

Kelp Forests

Healthy kelp forests support high levels of biodiversity and primary productivity, and underpin the provision of ecosystem services such as fisheries habitat and carbon cycling. Photo: Dan Smale

The geographical distributions of ocean-dwelling species such as seaweeds, corals, crustaceans and fish are strongly constrained by temperature. As such, climate-driven range shifts are particularly prevalent in marine ecosystems faced with recent rapid warming. My work aims to better understand how climate-driven shifts in the distribution, structure and performance of habitat-forming kelp species influences ecological pattern (e.g. associated biodiversity) and processes (e.g. rates of primary productivity) in temperate marine ecosystems. For example, in the UK, a warm-adapted kelp species is expanding polewards as waters warm, displacing cold-adapted species in certain locations, yet the wider consequences of such climate-driven substitutions are poorly resolved. Our work to date has shown that kelp species range shifts can lead to reductions in local biodiversity and changes in rates and timings of primary production. Given that kelp species function as ‘foundation organisms’ by providing habitat and underpinning primary and secondary productivity, understanding their responses to climate change is vital for managing and conserving temperate marine ecosystems.

The geographical distributions of kelp species in many regions is shifting in response to ocean warming. These climate-driven range shifts could alter local biodiversity, trophic interactions and carbon cycling, yet their direct and indirect effects are poorly understood. Photo: Dan Smale.


Mangrove forests are at the forefront of climate change and are expected to be particularly impacted by sea-level rise. Mangroves can only tolerate a certain amount of flooding, so have to trap sediments and make their own soils in order to keep pace with rising seas. However, surface elevation change in almost 70% of measured mangrove sites in the Indo-Pacific is lagging behind current rates of sea-level rise. This could have profound impacts on mangrove forests and the millions of people who rely on them for their livelihoods.

Mangrove systems are at the forefront of climate change

Swiss Mountain Grasslands

Climate change has strongly modified precipitation patterns in the Swiss Jura Mountains, with summer drought events occurring much more frequently over the last 10 years. Drought is considerably reducing grassland productivity but so far no change in plant community composition has been observed. In these grasslands, the high plant diversity, yielded by numerous subordinate species, plays an important role in the resistance and adaptation to drought. However, it is still unclear how these plant communities will be able to cope with multiple successive dry years. Unfortunately, we should know soon!

The plant community in the Swiss Jura Mountains. Photo: Pierre Mariotte

African Dryland Ecosystems

Water availability is an extremely important factor in determining the structure and function of many dryland ecosystems, such as savannas and rangelands. Plants within these ecosystems are adapted to long, dry periods. However, climate change is projected to increase the severity, frequency and duration of droughts in many regions. Although some plants may tolerate this drought, others will suffer. In East Africa, projections of changes to rainfall with climate change are uncertain; though most global climate models project wetter future conditions. If these projections come to fruition, there could be an increase in tree biomass. Higher atmospheric CO2 concentrations can also lead to faster growth rates in plants, which is likely to increase the amount of woody vegetation within savannas. Whether they are projected to become wetter or drier, African dryland ecosystems could look very different in a climate-changed future.

Dryland ecosystem in Amboseli National Park, Kenya. Photo: Rhosanna Jenkins

Dan Smale Associate Editor, Journal of Ecology
Daniel Friess Associate Editor, Journal of Ecology
Pierre Mariotte Associate Editor, Journal of Ecology
Rhosanna Jenkins Associate Editor for the Blog

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