Liesbeth Bakker, PhD
Researcher, Aquatic Ecology
Abstract Liesbeth Bakker, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, 6708 PB Wageningen, The Netherlands, firstname.lastname@example.org
From defaunation to rewilding with large herbivores
In the Athropocene humans have had a dramatic influence on the abundance and species richness of large herbivores, starting with the Late Pleistocene extinctions of megafauna such as mammoths and continuing into the present. These extinctions and range contractions have now been termed defaunation – the disappearance of native wild animals from the landscape. However, at present, there is a new conservation movement, following the principles of rewilding – defined as restoring the naturalness and completeness of ecosystem processes. Trophic rewilding is a subset of this, aiming to restore food web relation and missing herbivores and predators in ecosystems, thus increasing the abundance and species richness of large animals.
With the extinction of the aurochs and tarpan, native large grazers are a missing component in present-day landscapes in North-western Europe. Their place has been taken by domestic cattle and horses used for farming or in grazing management in nature reserves. Since the early 1980s this grazing management has gradually changed into rewilding, with the introduction of wilder types of cattle and horses in nature reserves, which are allowed to graze year-round, live in mixed herds of males, females and young and displayed natural behaviour and population fluctuations. At present, in The Netherlands there is a wide variety of domestic-to-wilder types of cattle and horses in nature reserves accompanied by increasing numbers of red deer, fallow deer, roe deer and wild boar and the more recently introduced European bison and water buffalo. Whereas rewilding with large herbivores is rapidly becoming common practice, science lags behind.
An open question is how defaunation and rewilding affect the ecosystems in which these large herbivores are removed, respectively (re-)introduced.
I will look at the ecosystem functions that large herbivores have and how they affect their environment. I will present data on the impact of large herbivores on plant diversity, nutrient cycling and landscape structure, and how we may predict these. I will end with an outlook on the open questions that need to be addressed.
Liesbeth Bakker obtained her BSc and MSc at the University of Groningen (NL), her PhD at Wageningen University (NL) and did postdocs at the University of Lincoln, Nebraska, USA, University of Alberta, Canada and at the Netherlands Institute of Ecology, where she completed a tenure track. She now is a senior scientist at the Netherlands Institute of Ecology (NIOO-KNAW). She also chairs the Centre for Wetland Ecology (CWE), a network of 20 fundamental science groups in universities and academic research institutes in The Netherlands and Flanders working on the ecology of wetlands. She has a strong interest in the impact of animals on the functioning of ecosystems. In particular the impact of vertebrate herbivores is core of her research across ecosystems, including grasslands, wetlands, and underwater in freshwater and more recently marine systems. She is an experimental ecologist, who likes to see proof of the impact of herbivores by performing field experiments manipulating their densities or presence/absence, for instance using exclosures. Furthermore she conducts smaller scale experiments in the lab using model species to identify underlying mechanisms of animal impacts. She has long-standing experience addressing the impact of large herbivores on plant diversity, landscape structure and nutrient cycling and applies this knowledge to study the impact of rewilding with large herbivores on the functioning of ecosystems. Apart for rewilding with large herbivores she works on projects on nature development in aquatic and wetland systems using rewilding principles.