Interacting impacts of land use and climate changes on ecosystem processes: from cyclic herbivores to predators of conservation concern.

Lead Research Organisation: University of Aberdeen
Department Name: Inst of Biological and Environmental Sci


In recent years, evidence has emerged that dramatic changes in ecosystem processes and functioning are taking place across Europe under the joint impact of climate change and human-induced shift in land use. One of the most spectacular change concerns the populations of keystone herbivore species such as voles and moths with cyclical dynamics that took place nearly simultaneously in much of Europe in the 1990s (Ims et al 2008). Changes in small herbivore dynamics have the potential to lead to ecosystem re-organisation and therefore represent a challenge for the conservation of biodiversity, for which clear management and policy have to be addressed quickly. Indeed several European species of high conservation concern, as well as many birds of prey, are intimately linked to cyclically fluctuating prey. This project encompasses ecosystems as diverse as Lapland tundra, Norwegian taiga forest, UK upland grassland, agricultural plains of France, and agro-steppe in Spain, where small rodents are widely seen as key-stone species for a diverse guild of predators, including species of high conservation concern such as Artic fox, hen and Montagu's harrier or red kite. Interestingly, the dynamics of voles or lemmings have lost their large amplitude and regular cycles in northern areas during the last decades (Norway, UK, France), while the first outbreaks were recently recorded in the south (Spain). The impact of the rodent cycle is likely to be transmitted in the food web of these ecosystems by indirect interactions through, for instance, prey-switching by generalist predators to alternative prey and might lead to a profound re-assembly of predator, parasite and plant communities. Trophic cascades might indeed propagate and amplify between trophic levels subtle changes in primary producer phenology in response to climate change. Understanding how ecosystem processes are affected by the cascading effects of changing small herbivore dynamics is a knowledge gap with tremendous conservation implications. Along with outstanding issues of theoretical interest in population and community dynamics, the main objective of this proposal is to tackle the corollary conservation issues. Acquiring a better knowledge of these complex interactions appears to be essential for designing effective conservation initiatives for top predators and the communities to which they belong. This European collaborative project has been designed around five nested work packages progress from fundamental to decidedly applied issues. First, we will test the following nested set of four hypotheses: 1. that there is currently a geographically extensive syndrome of environmentally-driven (climate and land use), season-specific, changes in small herbivore dynamics across widely different eco-regions in Europe; 2. that these changes have disproportionate (non-linear) impacts on demographic parameters of predators that exploit cyclically fluctuating herbivore prey; 3. that these demographic changes, in turn, impact directly on population viability of predators; 4. and indirectly influence other species in the food web through a cascading effect. The issue of changing rodent dynamics is thus critically important at the European scale, with implications of profound importance to conservation and ecosystem management. Within the last work package (5), we will systematically explore the conservation corollaries of the hypotheses tested that pertain to the impacts of climate and land use changes on biodiversity and to the conservation management of exploited and pristine ecosystems in the face of global change. These include the scope for mitigating and adapting to the changes through alterations of seasonal patterns of land use, and active management of influential species. Together with policy makers and stakeholders, we will explore the ecosystem-level consequences of our findings, alternative management practices and highly-relevant policy implications.


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Cornulier T (2013) Europe-wide dampening of population cycles in keystone herbivores. in Science (New York, N.Y.)

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Luque-Larena JJ (2015) Tularemia Outbreaks and Common Vole (Microtus arvalis) Irruptive Population Dynamics in Northwestern Spain, 1997-2014. in Vector borne and zoonotic diseases (Larchmont, N.Y.)

Description ECOCYCLES explored the consequences of profound changes in the dynamics of grassland rodents experiencing multi-annual cycles of abundance and exploited by numerous predators. Researchers from Norway, France, Spain, and the UK worked over 4 years to improve understanding of the resulting ecosystem changes taking place across Europe. They demonstrated a consistent dampening in the amplitude of vole cycles according to a common syndrome, probably reflecting a common climatic driver and involving a reduction in winter population growth. Cycles still prevail but they are now of much reduced amplitude. Locally however, variation in land use, such as increased irrigation of arid areas in Spain, grazing pressure by cattle, sheep or reindeers, or agri-environmental schemes also influences rodent dynamics. ECOCYCLES established that vole predator populations such as owls and skuas will decline in response to those changes, but there may be long lags for some species, the length of which reflect variations in predators life histories, and to a lesser extent climate. ECOCYCLES also documented indirect interactions in food webs involving small rodent cycles, such as a reduction in spillover predation on ground nesting birds, and higher levels of endangerment for the Arctic foxes that relies more on lemming and less on carrions that the red fox. Throughout, ECOCYCLES has worked closely with stakeholders, most notably in Spain where sustained dialogue and provision of information has turned acrimonious arguments on the impact on vole outbreaks on agriculture in a more rational evidence-based approach to minimizing damage to crops and biodiversity.
Many ecosystems are dominated by regular fluctuations in the abundance of grass-eating small rodents that act as prey for many predators species. Those cycles act like the "heart beat" of ecosystems. However those cycles in abundance have been changing recently, and there was much concern that this will profoundly affect the environment. As part of ECOCYCLES, researchers from Norway, France, Spain, and the UK worked over 4 years to explore the consequences of these changes in the dynamics of voles and lemmings in Europe.
First they analysed statistically the long records on the abundance of grassland voles, some going back 50 years. They showed that cycles still prevail but they are now of much reduced amplitude, the "heart beat" of the cycles has become much fainter. Locally however, human activities such as increased irrigation of arid areas in Spain, grazing pressure by sheep cattle or reindeer, or agri-environmental schemes also influence rodent dynamics but the global signal is expected to eventually override those influences.
ECOCYCLES established that numbers of vole predator species such as owls, falcons and skuas will decline in response to changes in vole density. This because the years of plenty when these predators used to reproduce most intensively are now rare. The speed of the decline will vary between species according to their fecundity, longevity and behaviour. Thus only if the low amplitude cycles conditions continue do we expect these species to disappear.
Pulses of vole abundance used to influence whole ecosystems. For instance, after vole numbers have crashed, predation on other species would increase temporarily. ECOCYCLES documented that such indirect interactions are much less pronounced now. For a critically endangered species, the Arctic foxes that heavily on lemming, competition with the red fox is heightened in the absence of lemming peaks. The spread of shrubs in the tundra is also accelerated.
Throughout, ECOCYCLES worked in close collaborations with people who manage the land and species for conservation or their subsistence. In Spain, where, in contrast to elsewhere, vole outbreaks recently appeared, we worked closely with farmers, conservationist and farm pest managers and succeeded in turning acrimonious arguments on the impact on vole outbreaks on agriculture in a more rational evidence-based approach to minimize damage to crops and biodiversity. We provided information, established a sustained dialogue and involved people in monitoring and experimental vole management.
The success of ECOCYCLES demonstrates the value of partnership working in ecology.
Exploitation Route Governmental and NGO conservation bodies have been alerted to the potential crisis affecting vole predators.
Awareness of continental scale impacts of environmental change has increased
Progress has been made in conveying scientific information to stakeholders
Sectors Environment

Description Key findings are included in IPBES assessments, in particular for the presently on-going regional assessment for Europe and Central Asia. The project findings formed the basisi of a policy brief prepared in collboration with biodiversa: "Conservation of small mammals and associated ecosystems", based on the Ecocycles research results, treats of the importance of European policies (for example, the Common Agricultural Policy, the EU Strategy on Climate Adaptation) and actions in the context of the conservation of small mammals and other species which depend on them.
First Year Of Impact 2014
Sector Agriculture, Food and Drink,Environment
Impact Types Cultural,Societal,Economic

Description Policy brief for EU level governemental official issues 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Policymakers/politicians
Results and Impact A policy brief, jointly written with staff from IUCN EU office and Biodiversa Staff summarises main findings and policy implications of project

A policy brief summarising the results and policy implications of the project has been produced
Year(s) Of Engagement Activity 2014
Description Press release and subsequent interviews and coverage highlighting Global Change biology paper 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact A Press release was release highlighting Global Change biology paper and was followed by several interview and multiple items in the UK andPress

A press release had much uptake from the times Scottsman Press and journal and others
Year(s) Of Engagement Activity 2014
Description Press release highlighting Science paper 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact A press release was issued by The University of Aberdeen highlighting the key message of the paper published in Science on 05/04/2013

A press release was issued by the University of Aberdeen in addition to the Science pack issue by Science. this led to 3 interviews and > 10 news items in the US and UK. this is in addition to releases issued by the 17 co-authors of the paper in their h
Year(s) Of Engagement Activity 2013