Migrations as a response to climate change Flashcards
What is the “ecological space” occupied by an organism?
The environmental conditions where populations of a species can survive without the need to migrate.
Example of ecological spaces in real world
Kestrels vs Owls
They overlap in their food requirements (small mammals)
But they obtain their food under different conditions.
What happens with species with different overlapping requirements for a critical resource or habitat?
Species will migrate to within their tolerance range.
Resources for better understandings plant altitudinal changes are the records held by:
Fieldwork
Ancient photographs
Georeferenced herbarium data
Accelerated increase in plant species richness on mountain summits is linked to what?
Warming
Ancient photography and maps technique
Repeat photography comparison
Useful technique in the analysis of long term ecological and geological landscape changes.
Step by step methodology to monitor the upward shift of forests
1) Historical records of vegetation at three peaks taken since 1940s by several researchers.
2) Photographs of these three main peaks and also from medium altitude taken since early 1940s
3) Orto-rectified aerial photographs from the 1050s to currents days (Cartographic institute of Catalonia)
4) 1945 vegetation map and 1994 forest map
5) Field visual examination of the Montseny mountains to confirm vegetation.
Examples of altitudinal shift
Altitudinal shift of the native and introduced flora of California.
Examples of latitudinal migration
Poleward range shifts on birds- nearly 60% of the 305 species found in North America in winter are on the move, shifting their ranges northward by an average of 35 miles.
Observed Impacts in range shifts in mammals
Red fox (Vulpes vulpes) is expanding into the arctic habitats. Arctic fox (Vulpes lagopus) has contracted to Atlantic.
What is an invasive species?
An introduced species that spreads rapidly.
Most introduced species are not invasive
A species may be invasive in some regions but not in others.
Invasive species are species that affect, economically, environmentally or ecologically, habitats where they have been introduced, either accidentally or deliberately, outside their normal past or present distribution.
Trait:
Asexual reproduction Fast growth/ maturation Rapid reproduction High dispersal capacity Phenotypic plasticity Tolerance to wide range of environmental conditions
Benefit
No need to find a mate Able to reproduce early/ often Easy to access new habitats Better able to exploit new habitats Reduced likelihood of mortality Able to feed/ grow on many different things
What is invasion?
The establishment of a species outside its natural range
What does invasion require?
Establishment requires dispersal across barriers, colonization, and successful reproduction
Invasive species and climate change
1) Mountain plant communities are not particularly resistant to invasion by exotic species.
2) New species, that may become invasive, will be entering regions due to climate change.
3) Climate induced stress in an ecosystem will facilitate invasive species arrivals
