Transcript Identifying Species Targets at the Landscape/ Seascape

Identifying Species Targets at
the Landscape/ Seascape Scale
Identify species outcomes for hotspot or
high-biodiversity wilderness area
Identify and delineate key
biodiversity areas for globally
threatened and geographically
concentrated species
Identify globally threatened and
geographically concentrated species
that cannot be conserved at the site
scale alone and require conservation
action at the landscape/ seascape scale
• spp. with large home ranges and nomadic species
• spp. that occur at low densities
• spp. that move between key biodiversity areas and other
migratory species
• spp. that now occur in small isolated subpopulations due to
habitat fragmentation
• spp. that depend on ecological processes that cannot be
maintained through protection at the site scale
Species with large home ranges
and nomadic species
• Population with X mature individuals
requires more area than in any of the Y
largest KBAs identified for the species
or in which the species occurs
Species that occur at low
densities
• Population with X mature individuals
requires more area than in any of the Y
largest KBAs identified for the species
or in which the species occurs
Species that move between key
biodiversity areas
• Dispersal: Sub-adult dispersal patterns cannot
be accommodated within any of the Y largest
KBAs identified for the species or in which the
species occurs;
• Migratory species: Populations regularly move
between KBAs.
Species that now occur in small
isolated subpopulations due to
habitat fragmentation
• All subpopulations have less than X mature
individuals with limited probability of
recolonization due to habitat fragmentation
Species that depend on
ecological processes that cannot
be maintained at the site scale
Quantifying Species Targets for
Minimizing Extinction Risk at
the Landscape/ Seascape Scale
Population type targets
• Population reduction less than 30% over 10
yrs or 3 generations
• Population greater than 10,000 mature
individuals
• At least one subpopulation containing more
than 1,000 mature individuals
• Mature individuals spread across more than
one subpopulation
• More than 10 locations
• Probability of EW less than 10% over 100
years
Area type targets
• No continuing decline in Extent of
Occurrence
• Area of Occupancy greater than 2,000
km2
• No continuing decline in area/ extent/
quality of habitat
Connectivity type targets
• No severe fragmentation (i.e. not the case that
most of the population found in small relatively
isolated populations)
Assessing Area and
Connectivity Requirements for
Species Targets at the
Landscape/ Seascape Scale
Assess area requirements to
meet area type targets
• Extent of Occurrence: minimum area
requirement = current extent of occurrence
• Area of Occupancy: minimum area
requirement = area of occupancy greater
than 100/ 2,000 km2 or current area of
occupancy
• Habitat: minimum area requirement =
current area/ extent of habitat, with quality
maintained
Assess connectivity requirements to
meet connectivity type targets
Fragmentation:
• Map fragments of suitable habitat within Area of
Occupancy;
• Estimate potential populations of largest fragments;
• If no fragment holds suitable habitat for a subpopulation of 1,000 mature individuals, then identify
options for connecting fragments to achieve
sufficient interconnected habitat to support target
subpopulation;
• Check that increased connectivity does not reduce
number of locations/ subpopulations to less than 10.
Assess connectivity requirements to
meet connectivity type targets
Fragmentation example: Tapirus pinchaque (EN)
• Population density is 1 per 5.515.87 km2 in protected areas;
• In Colombia, only 5-6 fragments
large enough to support 150
individuals (estimated minimum for
viable population in the shortterm);
Source: Lizcano et al (2002)
• Remaining patches could play an
important role in conservation of
the species if connected to larger
patches.
Assess connectivity requirements for
species that move between sites
Movement requirements:
• Determine movement requirements.
• Determine movement/dispersal ability and
assess possible limitations.
• Characterize and map current connectivity
within landscape/ seascape.
• Quantify/ specify connectivity requirements.
Assess connectivity
requirements to meet
connectivity type targets
Movement example:
• For some subpopulations, female migration to
upstream nesting sites up to 80km from normal
estuarine habitat.
• Main threat to migration is dam construction which
block routes.
• Target = connectivity between nesting and foraging
sites (i.e. absence of dams or adequate mitigation
measures such as turtle ladders)
Identify threats that indicate
area/ connectivity requirements
Type of Threat
Area Conn. Ecol.P Policy Other
1: Habitat Loss/ Degradation
Y
?
2: Invasive alien species
?
?
3: Harvesting [hunting/gathering]
?
?
4: Accidental mortality
?
?
5: Persecution
?
?
6: Pollution
?
?
7: Natural disasters
?
8: Changes in native spp. dynamics
Y
9: Intrinsic factors
?
?
?
10: Human disturbance
?
?
Assess area requirements to
meet population type targets
• Define habitat and specific resource requirements;
• Estimate mean population densities (of mature
individuals) and estimate total area of suitable
habitat required;
• Map appropriate habitats and specific resources;
• Identify any critical habitats and/ or specific
resources that can be protected at the site scale and
ensure these are incorporated in KBAs;
• Quantify any additional habitat/ resource
requirements to meet population targets.
Assess area requirements to
meet population type targets
Example: Casuarius casuarius
(VU)
• Mean population density = 0.52 per km2 so population of
10,000 individuals would
require 5,000-20,000 km2.
• Habitat and resource
requirements: Rainforest and
associated habitats – requires
access to water points and
mixture of habitats in areas
with seasonal variation in food
supply (fruit-bearing trees).
Map appropriate
habitats
Identify critical habitat/
resources for site-scale
protection in KBAs