Climate and Life on Earth V: Global change - biodiversity in the Anthropocene 1 Flashcards
Define the anthropocene
- the current geological age in which human activity has been the dominant influence on climate and the environment
- recognises humans as a major geological and environmental force
Describe the Anthropocene
- modified >50% terrestrial land cover
- consume c.40% NPP each year
- increased CO2 concentration to 410ppm
- 1 degree of warming
- 0.5-1M species to extinction brink
- removed or rendered critically endangered all trop predators on land and sea
- 60% decline in vertebrate populations since ’70s
when did the Anthropocene begin?
1610
Define biodiversity
- variability amount living organisms from all sources including inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes the diversity within species , between species and of ecosystems
- variation in genes, traits, species, communities, habitats and ecosystems
List some scales of biodiversity
- gene
- individual
- population
- community
- ecosystem
- biome
- biosphere
biodiversity can be assessed in terms of
1) richness (number of elements)
2) evenness (equitability of elements)
3) heterogeneity (disparity in element form and function)
What are the biodiversity elements usually measured?
- taxonomic species or subspecies
- phylogenetic species
- ecological functions
What are the 3 main ways of measuring variability in space?
1) alpha diversity
2) beta diversity
3) gamma diversity
Describe alpha diversity
pool of local species or other element
Describe beta diversity
turnover of species among sites
Describe gamma diversity
pool of region species
Describe the elevational diversity gradient
- changes in species richness with increasing altitude in mountains (e.g. Mt Kilimanjaro)
- many taxa peak at mid-altitudes
Describe clades of great biodiversity
- Lake Malawi cichlids
- Heliconid butterflies in Central and South America
Describe clades of little biodiversity
- Lake Malawi tiger fish
- Cethosia butterflies in SE Asia
Tropics
cradle a museum of young and old species
LDG
geographical variation in species richness
List 3 hypotheses for the LDG
1) area-based (spatial) hypothesis
2) evolutionary hypothesis
3) biotic hypothesis
What are the factors that affect biodiversity geographically?
- area
- climate stability
- solar radiation
- ambient temperature
How does area affect biodiversity?
- large continents in the Southern Hemisphere have more space with more niches, and more opportunities for diversification
- they also exhibit larger populations with lower rates of extinction
How does climate stability affect biodiversity?
stable, predictable resources allow for specialisation and hence speciation
How does solar radiation affect biodiversity
provides more energy for higher NPP, resulting in more resources, niches and opportunities for speciation
How does ambient temperature affect biodiversity?
higher ambient temperatures entail faster rates of evolution via higher mutant rates, faster physiological processes, faster rates of evolution and hence speciation
How does biodiversity beget biodiversity
- more species
- more complex species-interactions (host-pathogen, predator-prey)
- more co-evolution
- more speciation
phylogenetic trees have revealed
no correlation between age of lineage and number of species
List some hypothesis for phylogenetic variation in species richness
- life-history trait variation
- biogeographical factors
Describe how life-history trait variation affects phylogenetic variation in biodiversity
certain life history traits (such as dispersal) predispose lineages to radiate
Describe how biogeographical factors affects variation in phylogeny in biodiversity
- isolate populations from one another
- slows geneflow
- allows divergence and speciation to begin
Phylogenetic variation in species richness arises from
combinations of stochastic and deterministic factors
Describe biodiversity in South America
- most biodiverse content
- landscape change primary driver of diversification
- poor dispersal capacity of many species amplifies biogeographical effects
List some concepts that biodiversity is confused with
- nature
- wildlife
- natural resources
- ecosystem services
- green infrastructure
- the biosphere
Define nature
the world’s natural living and non-living features not created by humans
biodiversity short definition
- the variety of the living components of nature (all living organisms)
- the diversity of life within the biosphere
Define wildlife
well-known wild mammals and birds
Define natural resources
materials or substances occurring in nature that can be exploited for economic gain
- may be renewable, and derived from living resources (e.g. timber, bushmeat, firewood)
- may be finite, and derived from inanimate sources (e.g. oil and gas, minerals)
Biodiversity secures
the long term production of natural resources
Define ecosystem services
flows of benefits that people gain from natural ecosystems
Describe the relationship between biodiversity and ecosystem services
- strengthening and sustaining with resilience
- increased productivity and efficiency
- allows continuation in the long term
Define green infrastructure
network of natural and semi-natural features that provide benefits to people such as reduced air pollution, managed rainwater run-off and recreational facilities
List some green infrastructure
- hedgerows
- rivers
- green roofs
- parklands
Describe the relationship between biodiversity and green infrastructure
- more resilient
- greater continuation potential
Fine the biosphere
the part of the Earth’s system comprising all ecosystems and living organisms: the living layer of the planet
Why is it important to define biodiversity correctly?
- avoid false narratives
- avoid reductionism
- measurement
- monitoring
- conservation prioritisation
Describe species recognition in animals
- 1,371,500 described species
- 11million predicted top
Describe species recognition in fungi
- 100,000 described species
- 10 million predicted top
Describe species recognition in plants
- 307,700 described
- 450,000 predicted top
List some ecosystem services
- clean water
- fish
- wood
- pollination
- cool temperatures
- control flooding
- purify water
- store carbon
- clean air
- education
- recreation
- aesthetic
- stewardship
- habitat
- biodiversity
- photosynthesis
- soil formation
- food
What are 4 contributions of ecosystem services
- provisioning
- regulating
- cultural
- supporting
Describe the effects of biodiversity
- increases the efficiency and stability of ecosystem functions
- improves the flow of very valuable ecosystem services
How does biodiversity increase the efficiency and stability of ecosystem functions?
- increased plants, detritivores, herbivores and predators
- non-linear saturating effects
- impacts across trophic levels
List some ecosystem functions
- resource capture
- biomass production
- decomposition
- nutrient recycling
Describe resilience
the capacity of a system to resist and recover from perturbation
Biodiversity buffers against
change, and enables ecosystems to resist and recover
Describe connectivity
allows for migration and range shifts to track moving ecological niches as an adaptive response to climate change
Describe diversity
species richness safeguards evolutionary potential
- diversity, functional redundancy and abundance increase resilience
Biodiverse connected ecosystems accommodate
- climate extremes
- pathogens
- migration from forests and grasslands
Describe Panama resilience expts
- one-species plot growth is strongly regulated by climate events
- higher mortality during 4 year drought
Describe resilience expts in the USA and Europe
- productivity of low-diversity communities (1-2spp) changed by 50% during climate events
- high-diversity communities (16-32spp.) changed 25%
Describe resilience expts in Western Ghats, India
- greater stability of carbon capture in species-rich natural forests compared to species-poor plantations
- rate C capture in plantations 29% lower in dry season compared to natural forest plots
Valuate ecosystem services
<125 trillion US$ per annum
Valuate Amazonian rainfall
- 20Bn tonnes per day
- fuel agricultural economy of c.240Bn US$ in Latin America
Valuate pollination services
- £1.25Bn globally
- £690M in UK
