Biogeography Flashcards
What is Biogeography
Geography of life, Science of understanding spatial patterns of Biology
Organism distribution causes
Geographic template and when they change, Biota response, species interaction
Why is Biogeography important
Organisms’ importance, understanding uneven spatial distribution, adapting to environmental change
What percent of species face extinction due to climate change
15-37%
Whakapapa-
Kaitiakitanga-
Mauri-
Taonga-
Whakapapa - Understanding the total environment
Kaitiakitanga - guardianship of the environment
Mauri - energy, the life force of all things
Taonga - treasure, iconic species
Linnean system
Order-Family-Genus-Species
Terrestrial biomes
Areas of similar climates and vegetation
Environmental gradient
Change in abiotic (non living) factors through space (e.g moisture, altitude)
Species response function
Measure of the performance of a species along an environmental gradient
Environmental gradient conditions
Temperature, moisture, salinity etc
Environmental gradient resources
Food, water, space, soil, breeding, something competed for
Niche
The set of environmental conditions in which a species can survive in
Fundamental Niche
The set of environmental conditions in which a species can survive in the absence of other organisms
Realized Niche
The set of environmental conditions in which a species can survive with organisms present (geographic range)
Is realized niche or fundamental niche smaller
Realized niche
What can we see from an observed distribution of a species
Realised and environmental niche models, as well as predict potential distribution
IUCN red list criteria
Population reduction, restricted geographic range and extinction probability
What does IUCN red list criteria result in
The species being endangered or vulnerable
Species distribution types
Cosmopolitan, Disjunct, Endemic
Invasion Biogeography
Alien-
Naturalised-
Invasive-
Weed-
Introduced-
Alien - A species whose precense in an area is due to human activity
Naturalised - Alien species that manage to sustain viable populations
Invasive - Naturalised species dispersing far away from site of introduction
Weed - Any species that does harm
Introduced - Any species that has been transported by humans across a major geographical barrier
Species richness
Overlapping species ranges in a location
Cosmopolitan species traits
Wide niche range (large environmantal tolerance), Generalist, Rapid breeding, Short generation time (quicker evolution), Good disperser, Transported by people
Disjunct species traits
Relict features, Range contraction, Long-distance dispersal, Plate tectonics/sea level rise, Human habitat fragmentation (anthropogenic)
Endemism species traits
Relict features, Range contraction, Land patterns, Mountain tops/oceanic islands (isolation)
Biodiversity
Variety of life; includes diversity within species, between species and of ecosystems
How is biodiversity measured
Number of species and genetic diversity
Global species richness
Total known-
Total estimated-
Vertebrates-
Invertebrates-
Vascular plants-
Total known - 1.7 million
Total estimated - 9 million
Vertebrates - 70,000
Invertebrates - 1.3 million
Vascular plants - 390,000
Nz species richness
Total known-
Vertebrates-
Invertebrates-
Vascular plants-
Native and exotic vascular plants-
Percentage alien and endemic
Total known - 56,000
Vertebrates - 1,700
Invertebrates - 20,000
Vascular plants - 4,700
Native and exotic vascular plants - 2,200 and 2,500
50% alien 80% Endemic
Region hotspot criteria
> 1500 species of endemic vascular plants, lost >70% of original habitat
NZ Endemism in terms of taxonomic level and why
High endemism at species level
Low endemism at family/order level
Due to geographic isolation following gondwana connection (species derived from common ancestor)
Nz Endemism in terms of plant type
High rate of endemism in woody species (poor dispersers)
Low rate of endemism in ferns/orchids (good dispersed)
Drivers of Biodiversity
Biological processes: speciation and extinction
Environmental factors: Energy, climate, geography/area, time
Speciation
Process by which populations of same species evolve into two distinct species
Speciation types
Allopatric and Sympatric
Allopatric speciation
Vicariance, geographic separation of population into disjunct populations
Sympatric speciation
Speciation in Geographically unchanged areas
Types of extinction
local and global
5 mass extinctions
End ordovician, late devonian, end permian/guadaloupen, end triassic, end cretacous
Species go extinct because
Small fragmentated populations, reduced fitness and offspring success
Drivers of biodiversity - Energy
Solar input higher at mid than polar latitudes
There is more biodiversity in polar or mid latitudes
Mid latitudes
Drivers of biodiversity - Climate
Tropical climates are more stable and have no glaciations and low seasonality.
Drivers of biodiversity - time
Evolutionary (long term) - the world has been tropical longer than nontropical giving species time to evolve to tropical climate.
Ecological (short term) - higher environmental, climatic and geological stability in tropics giving species more time to disperse
Drivers of biodiversity - Geography/Area
Larger areas in equatorial areas meaning higher diversity of environment, more diverse species and therefore higher species richness
Patterns of extinction and immigration on islands
Island area and distance to mainland
Equillibrium species richness
We can expect smallest number of species on a small island far away from the mainland and vice versa
Species richness at equillibrium (Macarthur and wilsons theory on island biogeography)
Point at which species richness remains the same through equal rates of extinction and immigration, explains how spatial habitat arrangement can determine an area’s biodiversity.
Ecological community
Assemblage of several co existing and interacting individuals of different species in a location or habitat at a given time
Ecological interactions
Biotic (organism on organism), Abiotic (use of resources)
Community structure
Measure of biodiversity (how many species and to what abundance)
Measures of community structure
Species richness, Shannon-Wiener diversity index
Realised niche of a species determines its
Geographic range
The traits of a species in a community determines
How the species respond to the environment and what functional role they have in the ecosystem
Community composition
Species make up
Functional composition
Species traits of the different species, what role they play in the ecosysytem
Measures of community composition
Classification, ordination
Ordination methods
Principal component analysis (PCA), Non-metric multidimensional scaling (NMDS)
Convergent evolution (convergence)
When organisms that aren’t closely related evolve similar traits due to similar abiotic/biotic factors.
Ecosystem services
Functional and physical properties of ecosystems that are of use to people
Ecosystem services types
Provisioning, regulating, cultural recreation, supporting
How does biodiversity benefit ecosystem functionality
Complementary, Insurance effect, Sampling effect, Response effect
Four main processes of environmental change
Tectonics (separation from Gondwana), Tectonics (Oligocene drowning), Land uplift/mountain formation, Climate change
How have tectonics resulted in environmental change in Nz
Nz tectonic events have shaped Nz Biota with vicariance e.g Ratites
How has land uplift resulted in environmental change in Nz
Nz was originally a low lying archipelago well separated from the rest of the world, resulting in 93% of Alpine species in Nzs’ young mountains being Endemic.
How has climate change resulted in environmental change in Nz
At last glacial maximum, Nz had larger land area, lots of ice and mostly open grass/shrubland, restricting the forests to the warm Northern tip of Nz
When was the:
Nz seperation from Gondwana -
Nz Oligocene drowning -
Last glacial maximum in Nz -
Gondwana seperation - 60 mya
Oligocene drwoning - 23 mya
Last glacial maximum - 21,000 ya
Five main processes of anthropogenic environmental change
Land use, climate change, Nitrogen deposition, biotic exchange, Atmospheric CO2
Is Anthropogenic or natural environmental change faster
Anthropogenic
Species responses to environmental change
Adapt, move, die
Species processes to environmental change
Functional change (Phenology, change in species interactions), Range shifts
Phenology
Timing of a key life cycle stage
