Week 12: Biodiversity Threats and Conservation Flashcards
Threats to Biodiversity, Invasive species, Disease emergence and Conservation (23 cards)
Summarise the threats to biodiversity and the relative importance of each threat
- Habitat disruption (species pop)
- climate change (species traits)
- over-exploitation (ecosystem structure)
- invasive alien species (ecosystem function)
- infectious diseases
Explain the effects of habitat disruption, climate change and over-exploitation of biodiversity with reference to examples
HD: destruction (urban/agricultural take over, forest clearance, causes fragmentation so reduces pop size)
Degradation: (pollution from pesticides, fertiliser, acid rain - water soluble pesticides can be neurotoxins and so become env persistent)
Disturbance: (subset of pop affected so minor indv effects but can cause cumulative damage)
Climate Change: Indv/pop (phenotypic plasticity/ evolution) -> pop/species (migration + range shifts)
-> communities (species level selection) -> ecosystems
Over-exploitation:
-Unsustainable harvest: causes extinction of megafauna and animals used for food (fishing)
-Medicine: also the aesthetic market and industrial materials (value increases in rarity so exploitation increases
-Fishing: tipping points, unsustainable exploitation can shift a habitat into a low productive state of no return
Relate mechanisms of decline in small populations
- chance effects and population size
- demographic uncertainty
genetic problems
-inbreeding: causes genetic impoverishment leading to loss of evolutionary potential
The extinction Vortex: threats (habitat loss, exploitation ….) cause small fragmented, isolated pop -> inbreeding so reduced adaptability and survival -> then other chance effects such as catastrophes, env variation -> reduce pop size and this cycle continues till extinction
Understand and explain methods to estimate global species richness
- extrapolation using macro- ecological patterns (body size frequency distribution, latitudinal gradients)
- Diversity ratios: ratios in taxon number, host specificity: taxon ratios
-Taxonomic patterns: discovery accumulation over time
Use diversity ratio extrapolation to estimate species number at the global scale
exp:
(a) First calculate ratio fungi: plants
277/48 = 5.77
Ratio fungi: plants = 5.77:1
(b) Next extrapolate unknown global fungal diversity
270,000 x 5.77 = 1.56 million spp.
Contrast historical and current patterns of species loss
-Global diversity increases through geological time
-5 mass extinctions
-Background extinction rate
-Future extinction rates
Calculate extinction rates
E/MSY:
extinctions per million species years
(Contrived) example
1230 species, 13 extinctions, 100 years
13= observed extinctions
(1230* 100)= opportunity for extinction
Ext’n rate, E/SY = 13 / (1230 * 100) = 0.000106
Ext’n rate, E/MSY = E/SY * 1000,000 = 106
Define invasive species and describe their key characteristics, supported by relevant examples
a non native organism introduced as a result of human activity to an environment where it does not naturally occur and whose present causes or is likely to cause harm to the environment, economy or human health
Key characteristics: fast growth and reproduction (e.g. floating penny worth)
-good at living in human-altered env (e.g. Japanese knotweed, Argentine ant, giant hogweed)
- often generalists, can adapt fast and well to a wide range of conditions (brown rat, lionfish, German cockroach)
-good competitors, no competition in a new area, utilises resources unavailable for local species
Explain the ecological, economic, and human health impacts of invasive species with examples.
Ecological impacts: reduction of biodiversity (brown tree snakes), alteration of habitats /ecosystems (cane toad, rabbit), hybridisation with native species (ducks), divers of speciation (guppies)
Economic impacts: crop loss to agriculture, domestic cats cause $52 billion in economic costs
Human Health impacts: mosquitos are disease vectors for dengue fever, zika virus
Identify the pathways through which invasive species are introduced, with examples.
Human facilitated introductions: during international trade (zebra mussels), accidental release (e.g. pet trade pythons)
Intentional intro: Victorians and ornamental plants (Japanese knotweed, rhododendron), biocontrol (cane toad in Australia, Mongoose in the Caribbean and Hawaii)
Outline and characterise the main stages of invasive species management, provide examples.
- Intro: invader absent then few populations cause localized invasion
- after lag time, expansion occurs with strong pop growth and rapid dispersal
- Persistence: Invader fully established, widespread and abundant, natural fluctuations of pop size
Describe control strategies for managing invasive species, provide examples.
- strict border controls and quarantine
- pathway management
- public awareness and education
-Legalisation and policy
-Risk assessment and screening - clean equipment and vehicles
- early detection and rapid response
-mechanical, chemical, biological control (integrated pest management combining multiple control methods)
Define emerging and re-emerging diseases and provide relevant examples. Discuss why studying emerging infectious diseases (EIDs) is important.
- infections that recently appeared in a pop and have existed previously but are now rapidly increasing in incidence, geographic range or severity
e.g. smallpox, Ebola, diphtheria, typhoid
Why study: threats to global health, economical impact, social disruption, forecast future pandemics and enable rapid response and prevention
Define zoonotic diseases and illustrate your definition with examples.
Zoonosis: any infectious disease or infection that is naturally transmissible from vertebrate animals to humans. Can be caused by bacteria, viruses and parasites and then spill over into transmission of pathogen from original reservoir (animals) to new host (humans)
e.g.
Ebola: initial human infection through contact with infected bat then human- human transmission
Rabies: bats -> wild animals -> domestic dog -> human
Describe the key factors that contribute to the emergence of EIDs, and provide examples
- Introduction of the pathogen in a new host pop
- Establishment and dissemination within a new host pop
Key factors:
-Ecological changes (deforestation) increased human- wildlife contact, altered vector habitats, biodiversity loss, habitat fragmentation, intensified animal farming, water and food-borne diseases
-Climate change: increase pathogen survival and reproduction, climate- induced stress on host leads to susceptibility, lengthen transmission season. Influence on human behaviour: displacement and crowding, changes in recreational and social activities, changes in agricultural practices (deforestation, land use)
e.g.
-Lyme disease: ticks
-Zika Virus pandemic
Explain the concept of One Health and outline its main advantages.
WCS: called for international interdisciplinary approach to prevent disease and formed the One World One Health concept
Implementing programmes, policies, legislation and research in which multiple sectors communicate and work together to achieve better public health outcomes
- Hotspots, sampling strategy, testing strategy, risk characterization
-Adv: better understanding disease ecology, improves env risk assessment, provides stronger evidence of zoonotic transmission risk, max resources
Explain the basic economic rationale for conserving biodiversity, and discuss approaches to evaluate the costs of biodiversity conservation
“the great conservation bargain”
-costs include: implementation, buying, maintenance, protection and management, expansion and compensation
- whilst we spend around
$300 billion per year on conservation buying, surveying and protecting areas, the money we get back $240 billion by greening the wider landscapes shows a payoff making the cost much more justified
-Challenges: lack of standardized data/ consistent frameworks, need to integrate biodiversity in planning/operations, need more from policy, uncertain environmental integrity of offsets and mechanisms, insufficient industry and local community buy-in
Relate broad-scale geographical patterns in biodiversity conservation costs and in the consumption and generation of biodiversity resources
-more than half the planet’s species are endemic to 16% of its land area
-4/5 of terrestrial vertebrates occur in these hotspots
-2/5 of all species under extreme threat in 25 localities that make up 1.4% of the Earth’s land surface
-PROBLEMS in the hotspots: habitat destruction, climate change making it worse, direct exploitation, hotspots notable centres of violence (high pop/pop growth rates), often in the poorest countries so cannot afford to conserve and not all countries agree to aid
-The top 10 importing/exporting countries associated with pressure on biodiversity directly affects low income countries
Explain the development of global legal frameworks through time and their relationship with local (national) frameworks for biodiversity conservation
Convention on Biological Diversity (CBD) 1992 -not met
-three types of diversity (ecosystems, species, genetics)
-conservation, sustainable use, sharing benefits
-doesn’t incorporate diversity of the past
AIMS: (Aichi targets)
1. address reasons for loss of biodiversity by mainstreaming biodiversity
2. reduce direct pressures on BD and promote sustainable use
3. improve status of BD by safeguarding ecosystems, species and genetic diversity
4. enhance the benefits of BD to all
5. enhance implementation through planning, knowledge and management
UK national biodiversity strategy:
1.implementation
2. monitoring
3. timeframes
4. recognising ecosystem services
Critically evaluate the success of global legal frameworks for biodiversity conservation
-Framing of the Aichi targets: they were SMART (specific, measurable, ambitious, realistic, unambiguous
-intergovernmental science-policy body created with expert opinions
-None of the Aichi targets were fully met
Understand and relate the role of monitoring in underpinning the effectiveness of protected area networks
-1/6 terrestrial land is protected and increasing but not all change drivers are controlled
- Statutory protected areas: key responsibility for nature conservation and require a compliant to network of bodies
-Condition assessment: standardized , quick and easy
-Feature based: specific for habitats, species and landforms
-SSSI: site of special scientific interest
-NVC: national vegetation Classification
-Issues with NVC monitoring: dynamic change due to eutrophication and disturbance, need to identify NVC, vegetation as static desirable endpoints
Explain the concept of ecological deficit and understand its components
-Our ecological footprint (consumption, waste products, measured as are) is beyond Biocapacity (regenerative capacity, renewable resources, expressed as area)
Eco footprint of consumption= Eco footprint of production + Net Ecological footprint of trade
Explain the concept of a planetary boundary, including its potential value in relating earth system sustainability to policy makers
e.g. Climate change, novel entities, ozone depletion, atm aerosol loading, ocean acidification, biochemical flows, freshwater use, land system change and biosphere integrity
-There are 9 boundaries we
must stay within as safe limits for stability and resilience of the Earth’s system
- Transgression from these can drive large scale abrupt or irreversible env change
-They are interlinked and considered jointly
2023: 6 boundaries crossed
