Biological Invasions: The Human Dimension Philip Hulme NERC Centre for Ecology & Hydrology

Terminology Alien: A species that is not native to a country, region or habitat. Alternative terms include exotic, non-native and non-indigenous species (NIS) Naturalised: A species that is able to maintain a self- replacing population in a region where it is non-indigenous. Invasive: A species whose local abundance and/or geographic distribution is increasing, often in areas where it was previously absent. Current concern relates to biological invasions that result from human activities (introduction, habitat modification) although an increasing focus on unwanted natural colonisation events.

Alien impacts: non-native flora Campylopus introflexus Reduces Calluna regeneration Rhododendron ponticum Reduces species richness Picea sitchensis Ecosystem change Hyacinthoides hispanica Hybridization with natives Ambrosia trifida Health risk Oxalis pes caprae Economic damage

Alien impacts: non-native fauna Arthurdendyus triangulatus Earthworm predator Arion lusitanicus Economic damage Cervus nippon Hybridization with natives Fallopia japonica Wildfowl predator Sciurus carolinensis Wildlife disease Branta canadensis Social and economic pest

Bioinvasions in a global context Millennium Ecosystem Assessment: Ecosystems and Human Well-being – Synthesis 2005

International policy and invasions The European States have a commitment to: strictly control the introduction of non-indigenous species Bern Convention on the Conservation of European Wildlife & Natural Habitats eradicate those alien species which threaten ecosystems, habitats or species UN Convention on Biological Diversity ensure that the deliberate introduction into the wild of any species which is not native to their territory is regulated so as not to prejudice natural habitats within their natural range or the wild fauna and flora and, if they consider it necessary, prohibit such introduction European Union Habitats Directive

Risk Assessment LIKELIHOOD Economic Impact Environmental Impact Social Impact Management Costs Strength of Pathways Establishment Population Growth Dispersal HIGH RISK MEDIUM RISK LOW RISK HIGH RISK MEDIUM RISK LOW RISK CONSEQUENCE HIGH RISK MEDIUM RISK LOW RISK

Driving Forces: Transport & trade Greater connectivity through travel and trade provides opportunties for aliens Ponto-Caspian invasions Canal & river network link Black & Caspian to North & Baltic seas Lessepsian invasions Suez Canal opened in 1869 links Red & Mediterranean Seas

Understanding pathways: entry routes How many routes lead to species introductions? Contaminants of agricultural & aquacultural produce Contaminants of commercial grain supplies Seed contaminants of nursery & cut flower trade Organisms on timber Seed contaminants of soil Machinery, equipment, vehicles, aircraft Contaminants of packing materials Contaminants of mail and cargo Ballast soil Ballast water Hull fouling Tourists and their luggage Other

Sources on non-native plants in the UK Garden Escape Seed Contaminant Feral Crop Landscaping Aquarium Escape Medicinal Herb Forestry Other

Pressures: land-use change & disturbance Disturbance, fragmentation, eutrophication increase ecosystem vulnerability

Trends in invasion impacts Strongly negativeNegativePositiveStrongly positiveNo effect Economic impact Number of taxa Animals Plants Fungi & microbes Strongly negativeNegativePositiveStrongly positiveNo effect Environmental impact Number of taxa Animals Plants Fungi & microbes

Assessing impacts: invader removals X X American mink Mustela vison Nordstom et al Himalayan Balsam Impatiens glandulifera Hulme & Bremner 2006 Wire weed Sargassum muticum Sanchez & Fernandez 2005 Raccoon dog Nyctereutes procyonoides Kauhala 2004 Removal experiments are rare but necessary to assess correlative studies

Risk Assessment LIKELIHOOD Economic Impact Environmental Impact Social Impact Management Costs Strength of Pathways Establishment Population Growth Dispersal HIGH RISK MEDIUM RISK LOW RISK HIGH RISK MEDIUM RISK LOW RISK CONSEQUENCE HIGH RISK MEDIUM RISK LOW RISK

Likelihood

Impact

Integration

Aliens are often difficult to define Regional versus national perspectives The beech and hedgehog are viewed as both native and alien Established aliens part of countryside Pheasants and horse chestnuts Are accepted as part of UK wildlife Reintroductions Beavers and Norway spruce Once native to UK, so why not again?

King Crab: Paralithodes camtschaticus Commercial king crab fishery YearCatch Value K67 million NOK K93 million NOK K

Managing species: public perception

Conclusions The field of biological invasions has grown dramatically in last 20yrs High profile has raised public expectations of scientific deliverables Science needs move from quantifying problems to identifying solutions Several key areas include: 1.Quantifying the spatio-temporal dynamics at appropriate scales 2.Implementing robust monitoring strategies for rapid response 3.Identifying major tools & approaches to accurate risk assessment 4.Developing management guidelines based on ecological strategies Policy relevant science should still equate with cutting-edge research