Transcript Protecting Ecosystems

Ch. 11 Protecting
Ecosystems
“You take my life when you take the means whereby I live.”
ICUN recognizes 7 categories of protected areas
“A protected area is a clearly defined geographical space,
recognised, dedicated and managed, through legal or other
effective means, to achieve the long term conservation of
nature with associated ecosystem services and cultural
values.”
Reserve Selection
• Traditionally driven by aesthetics and recreation, not
biodiversity
• Need for biodiversity-driven decisions
• Two approaches
• Species based
• but how do we protect biodiversity when the majority of species
haven’t been described?
• Course filter
Centers of Species Diversity
• Species are not distributed uniformly across the globe.
• Hotspots of species richness or endemism
• pros: many species, small area
• cons: hotspots of richness, threat, endemism, for different taxa
don’t coincide
• Using GIS
• layer multiple datasets to protect
maximum # spp within smallest area
Ecosystems and Environmental
Surrogates
• Course filter approach assumes that protecting a complete set
of ecosystems will protect most species.
• Course filter approach requires system of ecosystem
classification based on
• physical environment
• species composition
• but remember dominant species often generalists, and species move
ranges
• Use environmental factors directly, not ecosystems
• Ecoregions
Filling in the gaps
• Usually adding a reserve to an existing system
• Gap analysis to identify what the existing reserves are missing
• High altitude regions generally over-represented
How much, how many?
• Enough to protect viable populations of species,
accommodate large home ranges, migrations, etc.
• World Conservation Union recommends 10-15% of the total
area of each ecosystem type be protected
• Currently 12% of land area protected, but imbalanced among
ecosystems
• too much tundra, not enough grassland
• less than half the area is under the strongest protection
Logistics
• Ideally decisions would be based solely on biological values
• Realistically:
• threat
• number of landowners/stakeholders
• current condition of area
Reserve Design
6 Features based on island BioGeo
• Larger better than small: recall species
area relationship
• Assuming same ecosystem type, single
large better than several small
• If you must have several small, avoid
isolation by having them proximate to
one another
• Clustering facilitates movement better
than linear designs
• Choose circular shapes to facilitate
dispersal and reduce edge effects
Reserve Size
• Benefits of large reserves
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wider range of environmental conditions
accommodate large home ranges
more likely to have rare species
accommodate area sensitive species
more secure, easier to manage
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larger populations, lower extinction probabilities
relatively smaller edges, reduced poaching, edge effects
less vulnerable to catastrophic events
efficiency of scale
• Minimum dynamic area: smallest area that holds an array of
patches in different stages of disturbance and succession
SLOSS Debate
Landscape Context
• Context matters
• Boundaries of reserves are permeable
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pollution
exotics
livestock
poachers
• Best to have a buffer from too much human intrusion
• easiest if reserves are circular and follow natural boundaries
• aim to encompass whole watershed
• usually follow political boundaries
• demilitarized zone between North and South Korea
Connectivity
• Few reserves large enough to protect completely
• Kinds of movement
• between patches, usually small scale
• annual migrations, range of distances
• mid-distance: reserve connectivity crucial
• long-distance: stepping stones
• dispersal, connectivity to members of the species living
elsewhere, avoid genetic problems
• range shifts, across continents over thousands of years
• reserves at multiple altitudes
• continental scale corridors
Designing connections
• Depends on the animal
• fence lines
• ocean currents
• enough habitat for breeding
• Acquiring strips difficult ~ many different property owners,
stakeholders
• Might improve connectivity for things we don’t want moving
• exotics
• disease
Reserve Management
• Human recreation: visitors, roads, pollution, waste disposal,
trampling, erosion, fishing, dead wood collection, disturbance to
wildlife
• locals occasionally allowed to take and sell reserve resources
• Natural processes: fire, flood, storms, insects
• public doesn’t understand why managers allow these things to occur
• how much interference after occurence? replanting, slope
stabilization
• Access to water
• people want more for themselves, less for reserve
• how do you manage the needs of different species?
• digging water holes for wildlife? cost to other spp? disease
transmission?
• Invasives
• public dislikes culling of wildlife, spraying of herbicide
• What is natural?
Discussion Qs
• Do you think reserves she be based on species or ecosystem
distributions?
• SLOSS? Where on the continuum do you fall?
• Would you create waterholes in arid reserves? Why or why
not?
• Do you think we should restore disturbed ecosystems after a
natural disaster? Why or why not?