Biodiversity, Ecology and Conservation Flashcards
Definition of ecology
Interaction between organisms (biotic) and their environment (biotic and abiotic)
Definition of biological species
Two organisms which cannot breed to produce viable, fertile offspring
Definition of population
A group of individuals of 1 species living and interacting in one area at a given time
Definition of community
Associations of populations of 2 or more different species in the same area
Definition of ecosystems
Community and physical environment and the transfer between different trophic levels in the whole environment
Definition of landscapes
Areas with considerable differences e.g. multiple ecosystems
Definition of biosphere
All the world’s ecosystems i.e. all living organisms and their environment
Definition of assemblages
A group of similar animals e.g. an assemblage of birds
Definition of population dynamics
How population size varies through time
Basic population equation and what it is used to calculate
Nt+1 = Nt + B - D + I - E
To calculate population size for animals with annual breeding cycles
Definition of geometric growth
Species population changes in size by a constant proportion in discrete time steps
Definition of exponential growth
Species population with continuous reproduction changes in size by a constant proportion at each instant in time
When does unlimited population growth occur?
- no competition and unlimited resources
- in small populations
- Newly colonised regions
- e.g. Muskox, Alaska
Important population measures
- Population size i.e. number of individuals
2. Population density i.e. number of individuals/ area or vol
What are area-based counts
Count sessile individuals or vegetation using quadrats or aerial surveys for large mammals in a known area
What are distance-based counts
Measure distances individuals seen from a transect line/ point to estimate relative number of individuals/ unit area
Definition of relative population size
Number of individuals in time/ place relative to a number in another
Methods used to measure population sizes
- Area-based counts
- Distance-based counts
- Capture, mark, release, recapture
Capture, mark, release, recapture equation to estimate population size
Total population (N) = (Number marked first catch (M) x total caught second catch (C) / number marked second catch (R) N = (M x C)/R
Assumptions and issues with capture, mark, release, recapture
- No B, D, I or E between M and R i.e. equal chance of capture
- No harm during process
- Marks do not fade
- Overestimate if animals learn to avoid recapture
- Underestimate if animals get preferentially caught
Definition of intraspecific competition
Competition within members of the same species as similar resource requirements i.e. demand>supply
Definition of interspecific competition
Competition between different species where both suffer negatively
Definition of carrying capacity (K)
The upper sustainable limit of a population
Begon et al. (1996) intraspecific comp. characteristics
- Effect is a measurable reduction in an individual’s contribution to future generations
e. g. a) fecundity (Cain 2011) - song sparrow breeding pairs and offpsring survival b) survivorship (van Balen 1980) - supplementary feeding and great tit breeding pairs - Resources must be in limited supply
- Reciprocity e.g. bird of prey chicks, spadefoot toad phenotypic plasticity
- Density dependent e.g. Tribolium confusum, soybean survivorship
Population growth models
- Exponential growth equation
2. Discrete logistic growth equation
Exponential growth equation
Nt+1 = reproductive rate x Nt
Nt = pop. size
Discrete logistic growth equation
Represents intraspecific competition
Nt+1 = reproduction rate x Nt (1 - Nt/K)
- calculate N at different time phrases
- plot Nt (y) against time (x) to see population growth
Characteristics of density dependence
- closely linked to intraspecific competition
- regulates population sizes around an optimum K value
Population regulation
- Regulating equilibrium around K by DD factor regulation (pop. often fluctuates)
- DD factors do not regulate if there is a time delay or if it only regulates in certain environmental conditions
- Different factors, e.g. food, waste, predation, may cause DD
What is cobwebbing (Ricker-Moran plots), how to use them and features?
Graphical method to predict the results of intraspecific competition and show population dynamics
- plot curve represented by the discrete logistic growth equation
- plot straight line to present unchanging population around K
- plot graph N against time
Changes to curve shape can majorly impact population stability and dynamics
Patterns vary i.e. cycles, oscillations, fluctuations
Ricker-Moran plot pattern examples
- Yeast rises smoothly with no fluctuation around K
- Callosobruchus beetles have a decreasing oscillating pattern
- Tasmanian sheep show regular fluctuations
- Great Tits have no order and wide fluctuations
Definition of mutualism
Both species benefit i.e. symbiotic e.g. zebra and oxpecker
Definition of commensalism
Presence of one species needed for another e.g. crabs and species living in their shells
Definition of predation
One species usually kills another
Definition of ammensalism
One species has a negative effect on another but it itself is unaffected e.g. elephants walking through vegetation
Types of interspecific competition
- Exploitation (indirect)
2. Interference (direct)
Definition of competitive exclusion
One species may have a competitive advantage over another resulting in one becoming out-competed (exploitation competition) and extinct
Example of competitive exclusion
- (Park 1948) flour beetles:
a) abiotic: T. castaneum wins 100% in hot-moist climate whilst T. confusum wins 90% in hot dry
b) biotic: confusum competitive advantage in presence of parasites - (Tansley) Galium species:
G. sylvestre outcompetes on limestone and G. saxatile on peat
Definition of niche theory
Ultimate distribution unit related to species’ ecological position
Types of niche
- Fundamental
2. Realised
Definition of niche partitioning
Alter and shift niche to reduce overlap and enable co-existence by avoiding/ reducing interspecific competition
e.g. (Gause) grown together P. caudatum ate bacteria on surface and P. bursaria ate settled bacteria
Niche partitioning mechanisms
- Resource Partitioning
2. Character displacement
Resource Partitioning
- Change niche components
- Reduce interspecific competition by narrowing niches
- May increase intraspecific competition
- e.g. (Schoener) 4 species of Anolis lizard live and eat similar food but height and thickness of perch and time spent in sun/shade differ
Character displacement
- Changing morphologically
- long term evolutionary response
- e.g. Hydrobia snails usually 3.5mm but together H. ulvae = 4mm and H. ventrosa = 3mm
- e.g. Geospiza finch beak size. G. fulignosa smaller than G. fortis
Brown and Davidson (1977) niche partitioning experiment
- exploitative competition between seed-eating ants and rodents
- ant colonies increase by 70% when rodents removed and rodents increase by 18% when ants removed
- interspecific competition - remove both seed density increases from 1 to 5.5
- interference competition - rodents enter ant burrows whilst ants sting rodents
- resource partitioning between ant species
- character displacement of ant foraging strategies
What are mortality/ survivorship curves?
Graphical representation of survivorship from life tables
Pearl (1928)’s survivorship curve types
- Low early, high late mortality e.g. humans, mountain sheep
- Constant probability e.g. passerines
- Very high early mortality but high survivorship if survive e.g. fish, LEDC humans (30% Gambians)
What are cohorts and life tables used for?
To study population trends and predict population sizes
Definition of cohort
Group of animals born in the same time interval. Track fate from birth to death for population information
Function of life tables
Provide information about birth and death patterns and summarise variations in survival and reproductive rates with age
Types of life tables
- Diagrammatic
2. Cohort
Diagrammatic life tables
- easy to follow
- harder to analyse and make predictions
- e.g. Great Tits have overlapping generations so individuals alive at t+1 = range of ages
Cohort life tables
- more reliable
- for continuously breeding or overlapping generations
- change in mortality with age/ stage
- construct fecundity schedules by measuring births at different ages
- plants, sessile organisms, animals with annual life-cycles
k-values (“killing power”)
- reflect intensity/ mortality rate at each stage relative to the next as sequential mortality factors
- scaled and standardised
- sum to show overall mortality
What is the key factor?
The most important k factor.
Correlates most closely with k-total and contributes most to overall mortality
What is the regulating factor?
k factor which correlates most closely is the main population regulator
Compare k-values with population size by plotting each k value separately against measure of population size over years
Types of life tables
- Fixed - look at a pop. cohort. Usually simple annual cycles
- Static - study whole pop. in a single year. Usually highly mobile/ cryptic species e.g. Red Deer on Isle of Rhum
Lowe 1969 static life table of Red Deer on Isle of Rhum
- reconstructed pop. age structure of 1957
- smoothed the data
- survivorship reduced with age
- High mortality at 8-10 years after high birth rate
Definition of true predators
Complete consumption of another species
Definition of parasites
Rarely kill host but effects vary. Obligate association with host (co-evolution)
e.g. pathogen, Myxoma virus
Definition of parasitoids
Kill host by laying eggs which hatch and eat host from within
Definition of hyperparasitoid
Parasitise on another parasite/ parasitoid
Definition of herbivores
Eat tissue/ internal fluids of living plants/ algae
Plant defences
- Chemical
- Mechanical
- Nutritional
- Tolerance
Predator-prey relationships
- Delayed DD coupled oscillations e.g. hare and lynx
- no link/ relationship e.g. woodmice and tawny owl
- Prey outbreaks
Hare population cycle
Krebs et al. 1995
- interaction between food and predator
- remove predator, hares increase x2
- add food, hares increase x3
- both, hares increase x10 but density still decline
Definition of monophagous
Single prey species/ genera therefore may have coupled oscillations
Definition of oligophagous
Few prey types
Definition of polyphagous
Many prey species
Evolutionary predator adaptations
- Physical e.g. speed
- Poison
- Detoxification/ chemical tolerance
Evolutionary prey adaptations
- Physical e.g. body forms
- Armour
- Behaviour
- Mimicry
Characteristics of specialist predators
Shorter search than handling time
Characteristics of generalist predators
Longer search than handling time
Predator switching
Predators may become specialist if they show a preference
Efficiency may increase with reliable search images
Ecological impacts of parasites
- Increase diversity if attack dominant competitor
- Reduce distribution range
- Near host extinctions
- Affect population dynamics
- Change physical environment
Community level interactions
- Direct i.e. between 2 species
2. Indirect i.e. relationship between 2 species is mediated by a 3rd (or more)
Definition of trophic cascade
Consumption at one trophic level causes change in abundance composition at lower trophic level and can affect whole ecosystem
Definition of trophic facilitation
Direct positive interaction between consumer’s prey and another species which indirectly facilitates the consumer
Definition of competitive hierarchy
Linear relationship as no feedback with a dominating species i.e. A -> B -> C
Definition of competitive network
Circular relationship between species as every species has a negative impact on another resulting in stability and co-existance as no single species dominates
Definition of keystone species
Relatively rare but disproportionally large impact on ecosystem
Definition of ecological dominants
Species which have large impacts due to high abundance
Disturbance
- can reduce population sizes so resources become non-limiting affecting species richness
- varies in intensity and frequency
- creates gaps allowing colonisation and creates a mosaic community
Intermediate disturbance hypothesis
Connell
- low disturbance/ climax community = low diversity as competitive exclusion via dominant species
- highest species richness at intermediate levels i.e. mid-succession
- high disturbance = low species richness as high mortality
- e.g. Sousa algal communities on rocky shores
Definition of biodiversity
The variability among living organisms: within species, between species and of ecosystems
Why conservation science important?
- Threatened species rising i.e. now 24,307
- Varies taxanomically e.g. 64% Cycadopsida threatened
- Extinction rates higher than normal background rates e.g. amphibians 66 to 107, 5 mass extinctions
- Dominant biodiversity loss drivers vary geographically (Sala)
When did the Anthropocene begin?
a) 1610 as CO2 concentrations began to rise
b) 1964 - radioactivity peaks
Biggest threat to mammals
Overexploitation with >6000 species affected
What is Conservation Biology?
- Soule 1985
- address biodiversity and nature issues caused by humans
- crisis biology i.e. act now, data later
- intrinsic value of biodiversity i.e. protection for itself
Conservation Biology value statements
- High organism diversity is good
- Extinction is bad
- Ecological complexity is good
- Evolution and genetic diversity is good
Conservation Biology Tools
- Singe large or several small (SLOSS), Simberloff and Abele, 1982
- Minimum Viable Population (MVP), Schaffer 1981
- Convention on International Trade in Endangered Species (CITES), 1975
What is Minimum Viable Population (MVP)?
Smallest number of individuals needed for an isolated population to persist at a preferred probability (90-95%) for a predefined time into the future (100 years)
What is CITES?
- international agreement between 183 governments
- regulates trade
- 3 appendices covering 5800 animals and 30,000 plants:
1. Cannot trade unless exceptional circumstances
2. Regulate trade to prevent worsening already threatened status
3. Between 2 countries. May be threatened in a particular country but not globally so may want to regulate trade
What is Conservation Science?
- Kareiva and Marvier, 2012
- coupled human - natural systems
- maximise benefits for nature and humans
- systematic data collection
- CB + human consideration
- instrumental value of biodiversity i.e. it also helps achieve other things
Conservation Science value statements
- Human well-being is important
- Maximise human and biodiversity benefits
- Evidence-based and community involvement
- Pristine nature does not exist
- Avoid ‘tragedy of the commons’
- Local and global conservation linked
How has conservation context changed 1985 vs 2012
- 40 % human population increase = increased demand
- CO2 increase and climate change
- More protection e.g. marine <1mil km2 to >8.1 mil
- Culture change
- Purpose has changed (Mace) i.e. 1960-70 = nature itself whilst now = people + nature
Conservation policies
- Convention on Biological Diversity (CBD)
- Strategic Plan for Biodiversity
- 17 Sustainable Development Goals
What is CBD?
- UN policy
- Following 1992 Rio Earth summit
- 2010 targets to reduce rate of biodiversity loss not met
What is the Strategic Plan for Biodiversity?
- 2011-2020
- 5 strategic goals each with 20 targets
- mostly insufficient/ no progress
What are the Sustainable Development Goals?
- UN
- broad blueprint for a more sustainable future
- reviewed annually
- meet by 2030
- more research linked
Conservation success examples
- Southern White Rhino went extinct in 1800s but rediscovered and NT in 2008. Following translocation and restocking now > 20,000
- Golden Lion Tamarain went from CE, 1996 to EN, 2003. Translocation and now around 1000 with 1/3 from captive stocks
- 68 status improvements
IUCN Databases
- ECOLEX
- Protected Plants
- Key Biodiversity Areas
- Red List of Ecosystems
- Red List of Threatened Species (1964)
IUCN species Red List criteria
- Population decline measured using counts, demographic data, presence/ absence
- Geographic Range Size i.e. spatial distribution in areas of known presence.
- Fragmentation
- Small Population Size - MVP, extinction vortex
- extinction risk assessed based either on decline rate over time or just point based
What is Population Viability Analysis (PVA)?
- Gilpin and Soule, 1986
- determine viability and extinction for particular time and environment
1. Time-series i.e. use estimates of total number to define average growth trend and variance
2. Demographic - use estimates of age/ stage specific vital rates
3. Individual based models and patch- occupancy data
How to measure Geographic Range Size
- Extent of occurrence - measure within boundary
2. Area of occupancy - sum of how many occupied grids
What is the Extinction Vortex?
- Gilpin and Soule, 1986
- abundance variability increases as population reaches extinction
- increased rate of population decline nearer extinction
- small pop = inbreeding/ reduced genetic variability =bottlenecks = low fitness = reduced tolerance
- e.g. carnivores reduced lifespan and offspring survival and fitness once genetic diversity lost
Largest threats to plants
Biological resource use i.e. logging
Most threatened species
Cycads
Species showing greatest levels of decline
Corals
Challenges measuring biodiversity
- Dark Diversity
- Sampling Bias - taxa, detection, geography
- Numbers described vs predicted
- Identifying new indicators
What is Dark Diversity?
- Species which should be there but are not
- Currently absent but could disperse and colonise the area
- Should prioritise areas with high observed and low dark diversity
What are the Aichi Targets?
- 5 strategic goals
- progress markers towards CBD 2020 targets
What are Essential Biodiversity Variables (EBV)?
- derived, standardised measurements needed to study, report and manage biodiversity change
- help provide indicators of progress towards CBD 2020 targets
1. Genetic composition
2. Population abundance and distribution
3. Traits
4. Community composition
5. Ecosystem structure and function
What is Adaptive Management?
- incorporating research into management
- systematic planning to test and monitor solutions effectiveness
- improve and update actions based on results and assessment
- understand which interventions work and then improve these e.g. Eastern Arc Mountain Tanzania
Island Biogeography Theory
- MacArthur and Wilson, 1963
- Pattern:
larger and nearer islands have more species - Processes:
a) increase distance = slower immigration rate
b) smaller size = higher extinction rate as more competition - doesn’t consider speciation
- isolation = selection pressures
- turnover rate (equilibrium) - calculate k to predict how many species should be present based on rates of immigration and extinction
- initial high immigration, as more arrive, extinction rate increases
- useful when considering fragmentation and PA locations
Island Biogeography examples
- Rakata - environmental change changed immigration rate as new ecosystems emerged
- Hawaiian Islands
very isolated chain of islands varying from Kure (15 my) to Hawaii (<700,000y). Climatic and vegetational variation caused speciation.
Types of “islands”
- Oceanic
- Land-bridge
- Habitat
Definition of metapopulation
A group of populations occupying different patches but connected by individuals’ movement
Metapopulation models
- Classical
- Mainland Island
- Patchy
- Non- equilibrium
What is the classical metapopulation model?
- small extinct-prone populations can be recolonised by neighbours
- all patches are small
- migration rate causes persistence
What is the mainland island metapopulation model?
- system of patches near a mainland patch
- migration from mainland patch prevents extinction of smaller surrounding patches
What is the patchy metapopulation model?
- no risk of extinction as migration between all patches
- large continuous non-independent metapopulation
- highly connected patches of different sizes
What is the non-equilibrium metapopulation model?
- no exchange
- sub populations = independent separate extinction-prone metapopulations
Types of habitat edges
- Natural e.g .Arabuko Sokoke Forest Kenya
2. Artificial e.g. roads, plantations
Definition of countryside biogeography
Inclusive of human-induced change and used to create more animal-friendly connections whilst benefiting humans
Definition of ecosystem functioning
The process species perform within an ecosystem
Ecosystem functioning theories
- Species Redundacy
- Rivet-popping hypothesis
- Insurance hypothesis
What is the species redundancy hypothesis?
- Walker, 1992
- removing driver species causes a cascade effect
- removing passenger species causes little change
- focus on functional groups i.e. low redundancy for continued functioning
What is the rivet-popping hypothesis?
- Erhlich and Erhlich, 1981
- all species contribute to functioning
- up until a certain threshold, losses are manageable but beyond threshold get catastrophic functional loss
What is the insurance hypothesis?
- Yachi and Loreau, 1999
- increasing biodiversity insures the ecosystem
- more species = more likely one will succeed and continue to provide a particular function
- more species = compensation for those that are lost
Relationships between ecosystem functioning and species richness
- Linear i.e. more species = greater functionality
- Redundancy i.e. only beneficial if function not already performed and less likely as species increase
- Idiosyncratic i.e. no pattern as depends on sequence of additional and removal. Community composition more important than richness
Definition of ecosystem resilience
The ability of an ecosystem to absorb disturbance without changing to an alternative state where it would lose function and services,
Definition of tipping point
Threshold at which you can get an alternative state
Definition of Protected Areas
A defined geographical space which is managed to achieve long term conservation and contribute to people’s wellbeing
Definition of Multiple Use Zones (MUZs)
Areas surrounding PAs to maintain movement or organisms, nutrients, E etc. but which have managed human activity
Definition of ecosystem stability
The invariability in function over time
Definition of in-situ
Protecting endangered species within their natural habitat to conserve ecosystems and recover/ maintain viable populations so biodiversity can maintain itself
What are Key Biodiversity Areas?
Areas which significantly contribute to biodiversity persistence and species survival
Types of Protected Areas
Ia. Strict Nature Reserve
III. Natural Monument/ Feature
IV. Habitat/ Species Management
VI. with Sustainable Use
Protected Areas Management Effectiveness (PAME)
Address human influence and the degree of protection and benefits based on criteria
- Laurance et al. = 50% reserves have biodiversity erosion and reduction in sensitive functional groups e.g. amphibians
- Leverington et al. = 40% management deficiencies
Usefulness of PAs
- Protect multiple species simultaneously
- Effective and secure
- Maintain viability and gene flow
- Protection from main drivers
Definition of translocation
Movement for conservation purposes from one site for release into another to either
- Introduce
- Reintroduce
- Restock
Likely to be successful translocation if
- Native, non-threatened
- High habitat quality
- Optimum niche away from edge effects
- Herbivores
- Early breeders
- Wild animals
Types of Translocation
- Population restoration
2. Conservation introduction
What is population restoration and the types?
Translocation within indigenous range
a) Reinforcement - intentional release into an existing population to boost numbers and genetic diversity
b) Reintroduction - intentional release into an indigenous range where it has disappeared
What is conservation introduction and the types?
Translocation outside indigenous range
a) Assisted colonisation - intentional release to avoid population extinctions e.g .climate change
b) Ecological replacement - intentional release to fill a perceived ecological gap/ function due to extinction
Pro conservation introduction arguments
Thomas 2011
- dispersal barriers prevent natural migration to more suitable habitats
- translocate within same geographic range which lacks endemics
Anti conservation introduction arguments
Ricciardi and Simberloff 2009 Vila and Hulme 2011 - well documented negative impacts of invasives - ecological disturbance risks - e.g. Nile Perch, American Red Squirrel
In-situ management successes
- Golden Lion Tamarin
Appendix I, EN as wild pop. = 800. PVA target = 2000. Combination of ex-situ breeding, habitat management i.e. Pocas das Antas reserve, 1974 and reintroduction via translocation of 13 captive, 1983 and 120 wild in 2000 - Large Blue Butterfly
Extinct in UK 1979 as obligate myrmecophile. Habitat management and reintroduction from Sweden, 1983-92 = natural colonisation by 2008 - New Zealand’s ground nesting birds. Predator exclusion and eradication and then reintroduction using captive bred individuals
Opportunity Costs
- locals dependent on areas now in PAs
- expensive to compensate e.g. Borneo cost of not planting oil palm = 46-48 $/ t CO2
- Expensive strategies
Definition of ex-situ
Protecting endangered organisms outside their natural habitat in a controlled, modified environment
Decision criteria to use ex-situ methods
- in-situ population near MVP
- Continued in-situ population decline despite action
- Population only lives outside PA
- Save EW species
Zoo benefits
- Keep those at risk of extinction alive
- Educate
- Fund research and projects
- Captive breeding and reproductive management
Zoo downfalls
- focus on expensive “charismatic” mega-fauna
- Don’t focus on species which would benefit from captive breeding and could be reintroduced into wild
- Detract funds from in-situ methods
- Limited resources
- Husbandry issues i.e. stress behaviours
- Domestication and loss of wild behaviours
What is the “Ark concept”?
Balmford et al. 2012 - Focus on: taxa not threatened by permanent habitat loss for successful reintroduction rapid small low cost breeders - Consider: captivity ease reintroduction feasibility indigenous species
What are EAZA Regional Collection Plans?
Developed by Taxon Advisory Groups to determine what should be kept, how and why and determine appropriate management as limited space and resources
European Endangered Species Programme (EEP)
- most intense
- maintain captive genetic diversity
- info on status of all individuals to determine future management plan
European Studbook (ESB)
- medium intensity
- population analysis based on EAZA data
- recommend either breeding, transfer or more intense management
Monitoring types
- low intensity
a) MON-P
b) MON-T
ex-situ guidelines
- Status review in wild
- Conservational role
- population size needed
- resources and expertise
Ecological scale
level of study i.e. individual vs ecosystem
Spatial Scale
Processes occur at small or large scales
What are general circulation models?
Numerical models using coarse i.e. 250-600 km scales to stimulate climate change response but may miss fine details so used alongside regional climate models with smaller dimensions (10-80 km)
Temporal Scale
Patterns visible at certain time scales may become noise at others
What are CCS - Integrated Conservation Strategies?
Hannah et al. 2012
Make conservation more effective by taking CC into consideration
1. Model regional biodiversity response
2. Select PAs based on CC and future movement
3. Incorporate corridors and areas outside PAs
4. Coordinate PA management across boundaries
5. Redistribute resources based on greatest CC contributors to greatest sufferers
What is climate - vegetation feedback?
Responses of ecosystems will in turn alter the climate
What is Reducing Emissions from Deforestation and Forest Degradation (REDD+)?
- UN programme in developing countries, 2008
- financial value for stored C in forests
- increased payment as emissions reduced
Relationships between poverty and the environment
- power, wealth, greed, exogenous and endogenous poverty and poor governance cause environmental degradation
- environmental degradation can cause poverty
What is “land sharing”?
- conservation farming
- continuous, heterogenous landscape
- maintain species and resilience
- humans part of nature
What is “land sparing”?
- separate PAs from farms
- binary landscape
- nature and agriculture separate
- humans separate from nature
What is the Ecosystem Services for Poverty Alleviation?
- UK led research
- sustainable ecosystem management and poverty decline in developing countries
What is the Natural Capital Project?
- US led research
- nature-based solutions
What is the Systematics Agenda?
- 2000
- catalogue all species and their distribution and relationships
Why are species estimates often uncertain and inconsistent?
- Lack of morphological variation
- Varied looking effort
- Varied ease of sampling
Value of biodiversity
- Ecosystem services e.g. resilience, regulation, provisions
- Genetic diversity e.g. wild tomatoes
- Well-being
- Use values i.e. direct and indirect
- Intrinsic non-use values
Role of Aristotle
384-322 BC
- first to catalogue based on observation and deductive reasoning
Role of Theophrastus
371-287 BC
- botany
- founded first ‘university’: Lyceum of Athens
- polynomial classification
Role of Linnaeus
1707-1778
- binomial nomenclature
- hierarchy
- classified 10,000 species
- classified plants based on flower sexual parts
What is the Catalogue of Life?
Most comprehensive online global species index database
Organism Kingdoms
- Prokaryotes
- Protocista
- Fungi
- Plantae
- Animalia
What happened 4.6 bya?
ARCHAEAN
Earth formed, no life
What happened 3.8 bya?
ARCHAEAN
Oceans formed
What happened 3.5 bya?
ARCHAEAN Prokaryotic cells (cyanobacteria in stromatolites) produced O2 via photosynthesis creating simple ecosystems
What happened 2 bya?
PROTEROZOIC
Ozone protection
Some prokaryotes use aerobic metabolism
What happened 1.8 bya?
PROTEROZOIC
Single-celled eurkaryotes
What happened 1.4 bya?
PROTEROZOIC
Multicellular green algae
What happened 600 mya?
PRECAMBRIAN
Soft-bodied metazoans
What happened 530 mya?
CAMBRIAN
Cambrian explosion = Burgess Shale fossils
What happened 440 mya?
SILURIAN
Ecosystem complexity
Complex arthropods
Colonisation of land
What happened 330 mya?
CARBONIFEROUS Vascular plants Synapsids Complex ecosystem conditions create niches to support biodiversity Insects
What happened 170 mya?
JURASSIC
Reptiles and birds
What happened 165 mya?
CRETACEOUS
Flowering plants
What happened 65 mya?
TERTIARY
K/T ME
Bird and mammal (placental) radiation
What happened 1.8 mya?
QUATERNARY
Modern mammals and humans
Species features most threatened from extinction
- Small populations/ ranges
- Live in human favoured habitats
- Large organisms
- Higher trophic level
People who made discoveries about mass extinctions
- Mary Anning, 1800s - dated fossils of different taxa
2. Cuvier, 1825 - many taxa disappeared simultaneously in Parisian basin
Late Ordovician Mass Extinction
- 440 mya
- rapid cooling causing glaciation and sea level drop
- anoxic waters
Late Devonian Mass Extinction
- 360 mya
- extraterrestrial impact
- global cooling
- rising sea levels causing anoxia
Late Permian Mass Extinction
- 250 mya
- largest with 95% marine and 70% land species lost
- rising sea levels causing anoxia
- climate change
Late Triassic Mass Extinction
- 210 mya
- extraterrestrial impact
- anoxia
- vulcanism changed climate rapidly
KT (Cretaceous - Paleogene) Mass Extinction
- 65 mya
- 75 % extinct including dinosaurs
- extraterrestrial impact causing climate change
- fireball generated smoke and dust reducing light and releasing gases
Evidence for extraterrestrial impact of KT ME
- iridium spike in >100 sites globally
- 180km wide Chicxulub crater, Yucatan
- Tungska, Siberia 1908 remnant meteorite shock flattened 80 million trees
Pleistocene mammal extinctions
- 20 mya in N. America
- megafauna
- environmental degradation i.e. glacial retreat and drier vegetation
- human overkill (Martin)
Causes of extinction
- Climate
- Biological
- Vulcanism
- Impact
Volcanic eruptions and extinctions
- Santorini, 1470 BC
- Krakatoa, 1883
- Permian
Evidence of continental drift
- Plate tectonics
- geological similarities at content edges
- floral and faunal similarities
- paleomagnetism
Effects of plate tectonics
- Dispersal
- Biodiversity
- Continental drift
- Change climate patterns
Plates and environment in Early Devonian
- 380 mya
- plates separate
- increase in land plants reduces albedo and increase in photosynthesis changes climate as temperature and CO2 drop
- fish and coral reef diversification
Plates and environment in mid Carboniferous
- 320 mya
- plates moving together
- global cooling
- flora along equator
- lycopods, calamites, cycads and tree ferns
- swamps bordered by deserts
Plates and environment in late Permian
- 250 mya
- deserts replace coal swamps
- mountains in N Africa
- migration of land vertebrates hindered in Euramerica
Plates and environment in Pangea
- 200 mya
- continents joined
- uniform fauna
- N = Laurasia, S = Gondwanaland
- dinosaurs dominate but mammals radiating
When does Gondwana begin to separate from Laurasia?
160 mya
What happens when continents begin to gradually break up?
- migration routes destroyed
- isolation
- global climate change
Techniques used to link past climate to biodiversity
- Geology
- Biological
- Stable isotopes
Geology - past climate and biodiversity
- effects of glaciation
- dates and conditions from rocks
- glacial and inter-glacial deposits
Definition of uniformatarianism
Using present conditions to understand the past
Biological - past climate and biodiversity
- fossils and species presence/ absence
- calibrate fossils to estimate temperature
- carbon dating
- permafrost
- peat - pollen grains
Definition of permafrost
Ground which has been continuously frozen for a minimum for 2 years
Definition of palynology
Study of pollen grains
Stable isotopes - past climate and biodiversity
- Oxygen
- calibrate with marine molluscs
Investigating glaciation
- Croll - Milankovitch cycles i.e. strength and location of solar intensity
- Levels if CO2 and CH4
Croll Milankovitch cycles
- Eccentricity
- Obliquity
- Precession
- correlate with glacial cycles
What is eccentricity?
- 100,000 year cycle
- how earth orbits the sun
- elliptical = contrast between winter and summer
- circular = constant solar E
What is obliquity?
- 41,000 year cycle
- amount of tilt
- seasonal change
- greater tilt increases size of seasonal cycle i.e. more sun in summer and less in winter
What is precession?
- 22,000 year cycle
- axis ‘wobble’
- direction earth points in relation to a fixed point in space
How did the climate at Sheppey change?
- Tertiary, 65 mya = hot and humid
- Eocene, 40 mya = warm temperate
- Miocene, 20 mya = modern temperature
Pleistocene glaciations
- 2.6 mya - 11,700 ya
- series of ice ages inter-spaced by interglacial periods
- every 100,000 years
- biomes shifts
- refugia and local extinction during glacial
- broad vegetation during interglacial
- intermediate latitudes = greatest genetic diversity
Effects of glaciation
- habitat fragmentation
- allopatric speciation
- bridges as sea levels drop
- filters
- new barriers
- extinction
- change soil/ vegetation
- hybridisation
How many biogeographic regions are there?
8
How many biomes and ecoregions?
14 biomes
867 ecoregions
What are biomes?
Similarities based on environmental conditions, structure and habitats
How many hotspots?
25 terrestrial covering 1.4% land surface
What are hotspots?
Regions of high endemism and biodiverity but high rate of habitat loss therefore are a conservation priority
Faunal changes during the Triassic period (250-200 mya)
- therapsids and reptiles disappeared
- dinosaurs spread 230 mya
- monotremes evolved
Mammalian evolutionary history
- monotremes evolved in Triassic
- placentals and marsupials evolved in late Cretaceous (100 mya)
- radiated globally and diversified after KT ME
- High endemicity in Australia and S America as isolated during late Miocene (12 mya)
- 57% terrestrial families endemic
Angiosperm evolutionary history
- primitive species in early Cretaceous
- modern families by 95 mya
- effective dispersal prior to Pangea breaking up
- now dominant plant species i.e. 90% with 300,000 species
- increased CO2 and temperature
Angiosperm characteristics
- doubled genome = new features e.g. Flowers
- drought resistant
- resistant seed coat prevents desiccation
- rapid life history and reproduction
- specialise and adapt rapidly
- co-evolution with insects
Definition of Cosmopolitan taxa
Found in all/ most regions e.g. house sparrow
Definition of Widespread taxa
Common only in suitable habitats in well-defined regions e.g. Cactaceae
Definition of disjunct distribution
Taxon with 2 or more groups but geographically separated due to migration barriers
What are centres of diversity?
Areas where conditions favour speciation/ survival
What are endemics?
Unique to one well defined region as either evolved in one location and stayed and due to fragmentation causing extinction bar one area
What are evolutionary relicts?
Population/ taxon more widespread in the past e.g. magnolias
Plant dispersal success
- resistant seeds
- travel long distances
- monoecious and self fertile
- aerial dispersal across geographic barriers
- vegetative reproduction
- primary producers
- fungal-resistant seeds
- adaptable e.g. invasives
Animal dispersal
- Mobile
- need 2 individuals from opposite sex
- require certain prey species
- parasites and disease
Migration
- Corridors
- Barriers
- Filters
- Bridges
Diversity controls
- Environment i.e. physical structures and resources
2. Competition
Plant dominance index
Phillip Grime
- measure of competitive ability
- aggressive species require lots of resources
- community change indicator
- score 1-5, add total and divide by 2 to score /10
- growth rate, height, spread, litter
- low scores = high diversity as co existence
- high dominant species control diversity and are controlled by resource availability
Diversity indicies
- diversity index
- species richness
- species rank
What is diversity index?
Measure of number and evenness
What is species richness?
Number of different species
What is species rank?
- most common
- k-dominance curves i.e. how dominant a species is
- low slope = dominated by 1 species
- high slope = quite even
Shannon diversity (H) and evenness
- measure number and richness
- assume random distribution and equal sampling
H = - SUM(pi ln pi) - higher = greater diversity
E = (H/lnS) - higher = more even
Simpson Dominance Index (D)
- measure degree of dominance
- D increases as domiance increases i.e. reduced evenness and diversity
D = SUM (ni(ni-1))/ (N(N-1)) - between 0-1. Closer to 1 = more dominance
1/D shows diversity. i.e. greater value = more diversity
Species area relationships
S = ca^Z
- small area = lots of species
- increasing additional species decreases as area increases
Colonisation of Hawaiian islands
- sea
- wind
- animals
- immigration
What is albedo?
A measure of a surface’s reflectivity i.e. lower = more radiation absorbed so temperature increases
Effects of temperature increase
- reduced albedo as more snow/ ice lost
- asynchrony
3 phonological changes - spread of disease vectors
Future climate predictions
- greater effects at higher latitudes
- desert expansion
- more extreme weather events
- sea level rise
- temperature rise
- vegetation shift
What are similarity indices?
Compare community composition i.e. which species are present