06. ECOSYSTEMS IN THE ANTHROPOCENE Flashcards
What was the significance of the Victorian government’s? 1988 Flora and Fauna Guarantee Act?
legal recog of imp biodiv for human + planet survival
What were the outcomes of the of the 1992 Earth summit?
- UN Convention to combat desertif
- UNFCCC
- Conv on Biological Div 1992
What were the outcomes of the Convention on Biological Diversity?
- signed by 173st
- req all sigs to devt nat biodiv strats + action plans - report updates every 5yrs
- nagoya protocol (fair access to genetic resources)
- cartegena protocol (GMOs)
- strat plan for biodiv 2010 = Aichi targets (2011-20)
- SDGs (2015-)
What did Aichi Target 12 promise?
- prev extinct of known threatened spp
- improve/sus of spp most in decl by 2020
Define ecosystem services
benefits humans derive from the environment + its resources
e.g.
- 2bn ppl rely on wood as primary E source
- nat pollinators contrib $560bn/yr to gl econ
(IPBES Global Assessment - Lecture 31, BIOL10010)
What are the 4 categories of ecosystem services?
- cultural e.g. recreational
- provisioning e.g. food
- regulating e.g. pollination, erosion regulation
- supporting e.g. nutrient cycling, PT
Key implications of IPBES Global Assessment
overall 50 yr global downward trend for regularory ecost services (a/t varying levels of sci certainty)
Evidence of rapid species extinction in the Anthropocene
- 20-25% assessed spp = at sig risk of extinct (IUCN Red List)
- =1mil spp
Animal groups in order of extinction risk
- amphibians
- mammals
- birds
- reptiles
- fishes
Global drivers of species extinction
v
Efficacy of current conservation action
NOT EFFECTIVE
- 25-25% assessed spp = at sig risk of extinct (IUCN Red List)
- =1mil spp
NEED TRANFORMATIVE CHANGE
- =1mil spp
What threat does biodiversity loss pose to the global economy?
biodiv loss = #3 in list of Top 10 Global Risks by Severity (World Econ Forum 2022)
5/top10 = environmental
Define the anthropocene
Refers to the geological epoch in which human activities are the primary influence on the environment.
preceded by holocene = prime environ for humans to thrive + expand
What are the biological indicators of the Anthropocene?
- inc soil N + P content bc fertilisers
- rapid inc in atm CO2 + CH4 conc
- dram inc in spp extinct
- deforest for ag, logging + urban devt
Identify the key biological and earth system processes that maintain stable climactic, atmospheric and environmental conditions on Earth
must remain w/in hard planetary boundaries for
- CC (C conc of atm)
- biosphere integ (biodiv)
- land-system change (defor)
⇒ Planetary Boundary Assessment 2015 = 4/9 processes already exceeded safe limit (Steffen et al. 2015)
Describe the carbon cycle and explain its link to anthropogenic climate change
land:
- plants absorb CO2 from atm during PT
- prod of PT = stored as plant biomass = C sink
- animals/bact/microbes eat plants + release C into atm thru resp
- plant biomass → soil biomass as plants drop leaves/die → embedded in sediment over time = becomes rock/ff
ocean:
- phytoplankton PT → create sugars from CO2 in air
- marine orgs respire/decompose → release C02 into water (some stored in ocean sediment)
- carbon transferred bw ocean surface, deep ocean + reactive sediments (C sinks) → released into atm via air-sea gas exchange
Outline how much carbon is in each major carbon reservoir and how much moves between them
per yr - Gt
flux:
- PT 120Gt/yr
- resp 60 Gt/yr
- microbial resp/decomp 60Gt/yr
- air-sea gas exchange 90Gt/yr each way
reservoirs:
- biomass 600Gt
- soils 1500Gt
- rock 100mil Gt
- FF 5-10K Gt
- ocean surface 1000Gt
- reactive sediments 6K Gt
- deep ocean 37K Gt
- sediments 150Gt
When do fossil fuels accumulate?
when dead plant matter accumulates faster than it can decay → layers of orgo C = FF
What are two ways human are changing the carbon cycle
added deforestion + burning FF → losing C sinks + inc amt C02 released into atm
= contrib 9 extra Gt C per yr into atm → 1/2 removed by fast C cycle but rest remains in atm
Explain how the anthropogenic alterations to the carbon cycle is causing global warming
inc inbalance bw carbon emissions + capacity of natural fast C cycle to remove C from atm → atm C02 conc x2 since pre-ind era (Met Office, 2021) → human enhanced GHG effect → gl warming
Outline the major impacts of anthropogenic climate change on ecosystems
atm:
- inc gl temps
- inc freq of extreme weather events
ocean:
- acidification
- inc H20 temp
- sea lvl rise
land:
- some inc plant growth (a/t lim)
- inc fire freq
- melting permafrost
Does the overall amount of carbon in the plant system change?
no but it does flow from diff reservoirs w/in system
Why is the formation of rock and fossil fuels not considered to be part of the ‘fast’ carbon cycle?
occurs over geological time scales
Explain the Intergovernmental Panel on Climate Change (IPCC)
Roles:
- assess + summarise research into drivers of CC
- assess threats posed by CC + how to reduce
Importance:
- prov transparent + reliable info
- central auth on CC action
- 195 members - diverse perspectives on CC
Outline the different climate scenarios presented by the IPCC’s AR6
Low emissions:
- SSP1-1.9 + SSP1-2.6
- emissions peak now
- 1.5-C warming
Intermediate emissions
- follows current trend
- SSP2-4.5
- emissions peak 2050
- 2.7 warming by 2100
High emissions
- SSP5-8.5 + SSP3-7.0 (’biz as usual’)
- emissions cont grow
- 4-5C warming by 2100
What are the key differences between implications of 1.5 and 2 degrees of warming?
- coral reefs - cover decl 70-90% @ 1.5C → non-existent @ 2C
- forest - inc severe forest biomass decl + inc defor/wildfires
- biodiv/ecosystems - 6% insects, 8% plants + 4% verts habitat range dec 50% @ 1.5C → 18/16/8% @ 2C
What proportion of animals in Australia are endemic?
- 87% mammals
- 93% reptiles
- 94% frogs
(Lecture 33, BIOL10010)
Australia is one of 17 _ nations
megadiverse (Lecture 33, BIOL10010)
Outline scope of species extinction in Australia
- 110 extinct since Eur col
- 1800sp = high risk
- 35% global mammal extinctinction
- 50% decl in avg bird abundance since 1985
- Aus = 2nd highest rate of biodiv loss (Waldron et al. 2013)
(Lecture 33, BIOL10010)
Australia is the ‘extinction capital’ for what taxonomic group?
mammals
‘Evil quartet/sextet’
=proximal (cf fundamental) drivers of extinct
- invasive intro spp e.g. cats kill 1.7bn native animals in Aus/yr (Lecture 33, BIOL10010)
- habitat loss/frag
- over exploitation e.g. TAS tiger
- co-extinctions
coined by Diamond (1989)
two novel factors:
- CC e.g. Gilbert’s poteroo = sml pop + range → 1 fire could cause extinct.
- disease
Ecosystems are fundamentally comprised of…
interactions bw living + non-living components
List some characteristic interactions in Australian ecosystems
- ice/snow x snow gums
- fire x euc forests
- sitting water x wetland spp
- high rain x RF spp
- low rain x desert spp
Explain why the preservation of mountain ash ecosystems is important
- CC prevention
- world’s lgest C store - stores 1900 t C02/ha (vs avg trop forest = 200-500t/ha) (Lecture 33, BIOL10010)
- clean drinking water
- single catchment prov 150bn L/yr (Lecture 33, BIOL10010)
- spp survival
- greater glider possum range is shrinking (Lindenmayer & Sato 2018) likely bc defor of mt ash
- econ
- fiscal value of water prov services = higher than C sequestering, timber prov, + recreational service combo (Nat Environ Sci Prog, 2017)
Describe how nature’s ability to provide benefits to people have changed
inc threat of CC → most econ/soc/environ responsible choice = conservation of C sinks that prov max ecosystym servioces e.g. mt ash forest
What does it mean for an ecosystem to collapse?
comp of ecological comm = transformed due to:
- loss of native biota
- environ degrad
- decl geog distrib
e.g. alaskan sea kelp in 1980s - overexploitation of sea otters → explosion of sea urchin pop → overgrazing → degred of sea kelp forest → ecosyst collapse (but event saved :))
Describe impacts of ecosystem change
scientists suspects mt ash ecosystem potentially undergoing ‘hidden collapse’
How is ecosystem collapse assessed?
IUCN created red list
criteria:
- decl distrib spp
- restricted distrib spp
- degred of abiotic environ
- altered biotic processes/interactions
importance:
- can be applied to any ecosystem
- transparent info
Rank five types of conservation interventions by how effective they are at supporting high levels of biodiversity.
- dec consumption
- sus prod
- cut pollution
- CC action
- conservation/restoration
Example of ‘transformative change’
Finance for Biodiv pledge → worlds leading financial instit (worth >14.7trEUR) pledge to ensure investments = biodiv pos
Name a major obstacle to preserving biodiversity in Australia
lack of funding - need $1.7bn/yr protect threatened spp from extinct - Fed + st govts only spent $120mil last yr
Outline five actionable interventions to prevent biodiversity loss in Australia
- priv protected areas/conservation orgs
- e.g. aus wildlife conservancy
- nat-friendly agri
- indig land mgmt
- comm action
- science/innov
Describe the Australian Wildlife Conservancy’s work
- manages 6.5mil ha habitat for threatened spp/ecosyst
- roles:
- feral cat/fxoc control (e.g. pred-proof fences prov vital conserv for 45 spp)
- fire mgmt
- feral herb control
- weed control
Describe Bush Heritage Australia’s work
- maintains reserves across Aus
- e.g. Nardoo Hills - restored grassy woodlands veg → successfully recovered multi spp e.g. fat-tail dunnarts + swift parrots
List the threats faced by Nardoo Hills ecosystem
plants
- dec water availability bc dec RF + inc temps
- invasive weed spp e.g. prickly pear cactus
- feral herbs e.g. deers, pigs, goats, rabbits
animals
- pred feral cats + foxes
- habitat loss - esp. trees prov shelter + breeding ground + food e.g. swift parrots
How are scientists working to increase ecosystem resilience in the face of climate change?
e.g. Nardoo hills
scientists introduced seedlings from drier/northern provenances → tested to see if grow better than local veg
solution = plant genetically pre-adapted seedlings now to ensure veg survives inc temp
Evidence of the severity of land clearance for agricultural use
- 395K ha cleared 2015-16 in QLD
- 60% aus land mass used for agri in some way
Examples of transformative change in agriculture
- Aus govt Biodiv Stewardship Fund = financial reward scheme to encourage farmers to reduce GHG emissions + improve biodiv on land
- Tiverton farm - pred proof fence w bandicoots inside → helps improve soil quality → LT beneficial for agri + conservation
Why is Indigenous land management crucial for threatened species conservation?
- nearly 60% Aus threatened spp have part/all distrib on Indig mgmt land (BIOL10010 L34)
- 44% total protected area governed by indig grps vs 42% by govt (Aus Govt DCCEEW)
Example of Indigenous land management supporting biodiversity
- martu country in WA
- home to multi rare + threatened spp e.g. black-flanked wallaby
- ranger program
- 300 ppl
- controlled burning dec severity + freq of late dry-szn fires (North Aus Fire Info)
- use knowledge of spp distrib + habitat prefs → tailor conserv interventions e.g. esp successful for billbies
Example of successful community action for conservation
merri creek - averted becoming highway → instead cherished reserve
Example of successful science in partnership for conservation
- low genetic div in Bulla MPP pop
- translocated 6 males 2011
- by 2015 87% pop had Hotham genes - hybrids = more survival + reprod success
What does the phrase Caring for country mean? How have Aboriginal people cared for the country over the last 65,000 years?
‘caring for country’
- way of managing environ holistically to support health of land + ppl + animals
- hinges on worldview where culture co-exists w nature
- focuses on stewardship values
What impact has European settlement had on Australia’s ecology? Why are so many species now in decline or threatened with extinction?
- disrupted cultural burning = Indig ppl’s opp to enhance health of land + ppl bc a) improve soil health + b) opp for plant reprod + c) dec fire severity
- t/f ecology + spp in decline bc a) low qual soil b) lost opp for reprod c) devastating fires
Why are Australia’s Tropical Savannas at such high risk of wild bush fire?
- prolonged dry szn (6-7mo)
- high biomass prod
- late dry-season 1mo ‘build up’ before wet szn → storms → lightning → ignites devo fire
⇒ inc opp + fuel to burn
Features of cultural burning practices
- targets sml areas
- tightly controlled acc to kinship + cosmo laws
What are the benefits of cultural burning in Australia’s tropical savannahs?
ecological:
- canopy intact
- low C release bc early szn
- encourages landscape heterogeneity → supports biodiv → ecosystem health
- dec freq + severity of late-szn fires
social (co-benefits):
- return to country - pos physical + psych benefits for FN ppl
Why is proper fire management importance for climate change mitigation?
wildfires contrib 3% Aus C emissions (BIOL10010 L35)
How does cultural burning help to protect/maintain the ecosystem?
- nutrient cycling → improve soil health
- ensures long-living spp X dominate - averts comp exclusion
- stimulates plant reprod
- dec freq + severity of late szn wildfires = contrib to CC + sig biodiv loss
After European settlement how did the fuel load of the landscape change? Did the environement become more or less prone to fire?
Eur invasion → disrupted fire regimes → biomass buildup → more prone
Current climate scenarios project…
earth cont warm regardless of actions BUT can mitigate + adapt
Example of Australian rodent that went extinct due to CC
Bramble key melomys
List CC adaptation strategies
- improved disaster response systems
- enhanced comm networks + resilience
- flood protections
What are some strategies that seek to both mitigate AND adapt to CC?
- responsible water + E mgmt
- edu
- innov new E systems
- restoration/protection of native ecosystems
How do different types of ecosystems help us adapt to and mitigate CC?
- forests - veg = C sinks
- grasslands - soil = C sinks
- mangroves - coastal buffer i.e. storm surge attenuation
- wetlands - flood water retention
Explain the difference between climate change mitigation and adaptation
mitig aims to minim extent of CC itself by curbing GHG emissions vs adaptation focuses on harm reduction
Define nature based solutions
using nat systems to prov sol to crises in way that benefits ppl + nat
i.e. recog that healthy ecosystems = healthy planet = healthy ppl
Describe how ecosystems can help reduce the severity of and impacts of CC through nature-based solutions
e.g. mangroves
mangroves:
- acts as C sink - mitig
- cushions impact of storm surge on coastal settlements/ecosystems - adapt
- oxygen water → create healthy habitat for fish/birds/multi marine spp - biodiv
Describe three examples of nature-based solutions
- reforestation
- C sink
- dec impact desert + improves soil quality → inc food sec
- enhances biodiv
- prov sus source of firewood/timber prod
- sea walls
- cushions storm surge impact → protect coastal settlements/ecosystems
- enhances marine div bc creates eco niches/microhabitats
- genetics
-Bush Heritage Aus intro genetically pre-adapted veg into VIC forests- improves ecosystem resilience
Identify key liveability and biodiversity challenges in cities and describe some nature based solutions being used to address them.
challenges:
- urban heating
- absorb lots of heat in day + cool v slowly
- hot nights = cause of heatwave mort
- flooding
- poor health/wellbeing - disconn from nat
- biodiv loss
solutions:
- inc tree cover
- dec urban heating
- e.g. Melb Urban Forest Strat
- water gardens
- absorb excess rainwater → minimise flooding + prov habitat
- e.g. highline NYC; creek uncovered from 8lane freeway in Seoul
Describe the goal and outcomes of Melbourne’s Urban Forest Strategy
- goal = inc tree canopy cover 22% 2012 → 40% 2040
- intended outcomes: dec pm temp, inc tree div, improve soil qual, inc biodiv
Contrary to population belief, cities are actually…
hotspots for biodiv + home to more threatened spp that rural areas on avg
Non-flowering plants are limited in their ability to support biodiversity because…
pollen + nectar = opp for interspecific interactions → invites variety of spp in area
t/f melb testing infecting non-flowering trees w native mistletoe (parasitic + angiosperms) → enhance biodiv
Explain the Extinction of Experience and why it’s important.
EE = quality time ppl spend in nat trending down
time in nat = imp for humans bc:
- stress reduction
- dec crime + aggro behaviour
- improve cog function in kids
- promo sense of comm + place
- contrib to ID
- mitig heart disease/diabetes/cancer mort
time in nat = imp for planet bc:
- less time in nat → less interest → less support for conservation
Describe some approaches to enhancing nature experiences in cities
- improve walkability
- preserve remnant veg
- green walls + roofs
- citizen sci projs
- mid-rise arch
- reforestation of nativ spp
Explain the importance of semi-private green spaces
promotes stewardship values
List two EPBC-listed species from the temperate grassland of Victoria’s Volcanic Plain and describe the conservation action being taken for them.
- striped legless lizard
- growling grass frog
2009 Melb Strategic Assessment aimed to offset habitat loss by creating grassland reserves BUT unsuccessful bc difficulties acquiring land
Threats facing species in the temperate grassland of Victoria’s Volcanic Plain
- urban devt - eco deserts
- invasive spp (weeds)
- changed dist regimes
Reasons why First Nations burning practices are better than conventional government burning practices
- dec A burnt
- dec intensity
- dec C emissions over time
Factors to consider in an urban forest
- tree spp
- habitat needs
- human health
- CC
- C sequestering capacity
List processes part of the fast carbon cycle
- PT (120Gt/yr)
- resp (60Gt/yr)
- microbial resp + decomp (60Gt/yr)
- air-sea gas exchange (90Gt/yr each way)
List community responses to obstacles re conservation
- X know what to do → devt strat plan
- X know how to do it → collab w local govt + attend planning tribunals
- X have $ → media advocacy + apply for grants
What introduced species threatened the greatest number of Australian endangered species?
rabbits
