1. Valuing the Impact of Incursions on Biodiversity: Wilding Trees
Basil Sharp & Geoff Kerr

2. Wilding Trees Self seeded trees growing where we don’t want them
Mainly conifers (our focus)
Lodgepole Pine (Pinus contorta)
Larch (Larix decidua)
Dwarf Mountain Pine (Pinus mugo)
Scots Pine (Pinus sylvestris)
Corsican Pine (Pinus nigra)
Douglas Fir (Pseutostuga menzeisii)
Scots Pine

3. Introduction Estimates of impact on commercial activity
Little work appears to have been done on value of lost biodiversity
We provide:
Very brief overview of literature
Proposed wilding trees study
Outline of approach
Douglas fir

4. International Literature
Pathways and impacts:
uncertainty over invader’s pathway once arrived;
little known about ecosystem response but indications are that focus should be broad and include temporal component.
Theoretical models:
damages = f(changes to ecosystem, environmental conditions, policy response)
Valuation: market + non-market

5. Wilding Trees Problem: Exotic species invading high country grassland
Spread over large area
Prolific seed production, predominantly wind dispersed (up to 10kms), successful germination depends on state of grassland
Impacts:
plant and animal communities (local extinction),
soils and hydrology,
increased fire risk,
landscape,
recreation,
cultural,
land use
Lodgepole pine

6. Management Options for management: Where, when, how?
Do nothing
Prevention
Containment
Removal
Where, when, how?
Costs v. benefits of management options
Robust Grasshopper

7. Control & Removal Manual Mechanical Spraying Grazing Competition
Biological
Fire
Control & Removal

8. Methodology Focus groups Choice experiment
Urban / Rural and North Island / South Island
Measure understanding of what wildings are
Identify perceived impacts
Identify salient attributes
Identify perceptions of merits of control
Understand factors driving control preferences
Choice experiment
Groups
In person
Large number of choice events