identifying species targets at the landscape/ seascape scale
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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
• 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
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
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)
Sou
rce:
Rus
s (2
000)
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 targetsFragmentation:• Map fragments of suitable habitat within Area of
Occupancy;• Estimate potential populations of largest
fragments;• If no fragment holds suitable habitat for a sub-
population 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 targetsFragmentation example: Tapirus pinchaque (EN)
• Population density is 1 per 5.51-5.87 km2 in protected areas;
• In Colombia, only 5-6 fragments large enough to support 150 individuals (estimated minimum for viable population in the short-term);
• Remaining patches could play an important role in conservation of the species if
connected to larger patches. Source: Lizcano et al (2002)
Assess connectivity requirements for species that
move between sitesMovement 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 Other1: 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 Y9: 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.
Example: Casuarius casuarius (VU)
• Mean population density = 0.5-2 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).
Assess area requirements to meet population type targets
Map appropriate habitats
Identify critical habitat/ resources for site-scale protection in KBAs
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