 Thanks very much Bernard and thanks for the invitation to speak. My name is Ian Scoons, I'm a professor at IDS at the University of Sussex in the UK and lead the ERC funded pastures program and I want to argue that assuring good human health and preventing zoonotic disease outbreaks requires healthy ecosystems and for rangelands around the world pastures are essential and essential to nature conservation. This project has been working in six countries on three continents and very diverse settings from the high mountains of Amdo to Beirut, in China to the savannas of East Africa, to the grasslands of Kutch in India, to the desert edge in Tunisia, to the Mediterranean environments of Tardinia in Italy. As this map shows, rangelands where pastures live make up more than half of the world's land surface and are vitally important but very poorly understood ecosystems. Rangelands include savannas, tundra, steppes, parkland and they're all what are called open ecosystems where trees and grasses are mixed in variegated patches. These are highly biodiverse and are maintained by a combination of grazing and other forms of herbivory and fire. Open ecosystems are frequently not at equilibrium, they don't have a fixed stable state, they're always in flux. Mystic livestock have long been central to such ecosystems, often in combination with grazing wildlife as in the savanna plain of East Africa. Yet too often such systems are assumed to be degraded, desertified, simply wastelands and not the highly productive, biodiverse carbon stores that they are. These perceptions arise from deep misunderstandings about how such ecosystems function and the role of livestock in maintaining ecosystem health. A Western gaze assumes that such areas with few trees are degraded, that lack of grass in a dry period is a sign of desertification, that livestock inevitably are causing climate change and that mobile systems are backward and damaging by biodiversity. Responses often mastery planting in rangelands, fixed and fenced, protected areas and arguments for reducing livestock populations and settling pastoralists with alternative livelihood. This view of conservation and development is seriously misplaced. A better understanding of mobile pastoralist systems, this is emerging through our work and many others, suggests that pastoralists are vital for biodiversity conservation. Displacing pastoralists from so-called protected areas, as is happening in Tanzania currently with the Maasai and Loliondo, will do more harm than good. Thinking about targets for protected areas globally needs to take account of different livelihoods and different ecosystems. Exclusion is usually not the answer. I want to now highlight six ways that pastoralists are important for ecosystem health and conservation. First, mobile grazing both responds to and creates environmental variability through light disturbance and the deposition of dung and urine. This can enhance species of biodiversity in rangeland ecosystems. Second, movement across landscapes, for example through transhumans, can assist seed dispersal, promoting biodiversity and plant conservation. Transhumans' roots are widely recognized as important bio-corridors and they are crucial for species and landscape conservation. Local key resources, which are vital for livestock feeding and watering, are also crucial for migrant bird populations, but drainage and increased pesticide use for agriculture can upset its interaction. Pastoralist systems protect important genetic material through the practices of pastoral livestock breeding, creating animal biodiversity and resilience against disease and other threats. Livestock in certain valuable keystone species often live side by side. For example, in Europe endangered vulture species are reliant on scavenging, dead livestock perium. Grazing by pastoral livestock is essential for the removal of dry biomass and the suppression of hot and dangerous fires. Yet in the Mediterranean region, declining pastoral populations have been associated with increase in highly damaging fires. Rather than pastoral systems, it's livestock systems that are intensive and concentrated in one place with close and continuous human contact, where the dangers of zoonotic outbreaks lie. Instead, a biodiverse, rich ecosystem that is managed by pastoralists is much more likely to stop dangerous zoonotic spillovers and protect human health. In some, mobile diverse pastoral systems managing open ecosystems in sustainable ways together with nature must be central to future thinking about protecting our shared natural heritage at COP15 and beyond. Thank you very much.