biodiversity Flashcards
(17 cards)
decline of the vultures due to human activity study -
Buechley et al (2016)
Buechley et al (2016) - study explain
Vultures the only obligate vertebrate scavengers (rely almost entirely on scavenging for food) - in an avian scavenger crisis = have experienced rapid and dramatic decline in their population and conservation status globally
decline due to = dietary toxins
Vultures ingest toxin by feeding of dead carcases of livestock that have been treated with the drug shortly before death = leads to kidney failure
what are the effects of vulture decline -
Triggers significant trophic cascades and ecological conscequences
With fewer vultures to quickly consume carcasses – carrion ability increase for other species
Dead to increases in populations of facultative scavengers, mesopredators and invasive species
Consequence = increase disease transmission = vultures possess highly acidic stomachs that efficiently destroy most pathogens in carrion
Facultative scavengers do not have this adaptation more likely to contact and spread diseases among themselves and to humans
emergence of the small shy fish study name and date
Monk et al (2021)
monk et al (2021) - explain
Highlight how harvesting of fish can act as significant selective force that can drive evolutionary changes in populations
Harvest induced evolution
Suggested that fishing is one of the few anthropogenic selective forces consistently stronger than natural selection
To understand total selective forces acting on phenotype the counteracting forces of natural selection must also be considered = for sustainable resource management and conservation it is critical to anticipate for the evolutionary changes
how are humans altering size of fish?
Harvesting increases adult mortality –> can favour life history adaptations that prioritise current reproduction over future reproduction
In most fisheries there is a positive relationship between vulnerability to harvest and fish body size
Larger fish more likely to be caught = leading to decrease in average fish body size
Decrease initially results from the direct removal of the larger fish (demographic truncation) - but also stems from evolutionary adaptation
Altered fitness landscape favours individuals that are smaller and reproduce earlier = less energy spent of growth and more on reproduction leading to smaller fish
behavioural changes in fish
Capture of fish reliant on active fish that take more risks
More vulnerable to be captured if active and bold
Selective capture of the aggressive, active and bold fish can promote emergence of timid populations
Diversity across scales study
Le Provost et al (2023)
Le Provost et al (2023)
Protecting and promoting diversity at multiple spatial scales – not just plot level species richness is essential for sustaining a broad suite of ecosystem services in agricultural landscapes
Examines – 150 european grassland plots assess supploy of 16 ecosystem services – cultural, provisipnal and regulating services
provost et al (2023) - Dual scale diversity drives services
Cultural services (eg flower cover and birdwatch value) and above ground regulatory services (pollination, est control) depend significantly on both alpha and gamma diversity)
2) Services such a biomass and soil nutrient retention are primarily influenced by field level land use intensity ad environmental context rather than biodiversity
implications of provost study on managememt of landscape?
-Sustainable agriculture should maintain permanent diverse grassland patches within landscapes to ensure multi-functionality – particularly for cultural and regulating services
-Policies must account for multi scale biodiversity = to focus solely on plot level diversity is insufficient
methorst et al (2021)
biodiversity effects on mental health
-Number of species in area dirvectly related to mental health
-The more species a park has the less hospitalisations fot meantal health related issues
-Also foud that siatance to parks has hegative correlation with mh
= further away = worse mental health
-Urban planners should consider supporting biodiverse environments to promote mental health
-Species diversity could be salutogenic = health promoting characteristic
biodiversity effects on mental health
Methorst et al (2021)
biodiversity and ecosystem function study
Reich et al (2012)
Compared ecosystem productivity in grasslands with high diversity with low diversity grasslands
Found ecosystem productivity increases with biodiversity
The longer the time scale the stronger the positive impact on diversity
Diverse plant communities become more efficient at using available resources over time
Species interactions leas to complementaru resource use (e.g. rooting at different soil depths, varying nutrient uptake strategies)
These effects accumulate time increase overall function
Functional diversity increases with time
So does functional redundancy
Positive diversity dependent feedbacks enhance ecosystem functioning as ecosystems mature
study to contest the positive relationship between biodiversity and ecosystem functioning
Hagan et al (2021)
Hagan et al (2021) findings
Controlled experiments often demonstrate these positive BEF relationships but much more variance in Observational field data
Can include neutral and negative BEF relationships
Suggest this variability partly due to biotic interactions during community assembly filtering species, which can lead to high ecosystem functioning even when local biodiversity (specifically, realised diversity) is low
Biodiversity loss at regional scales – specifically loss of local species pool diversity due to regional extinctions and habitat fragmentation can negatively impact ecosystem functioning in the long term - even if local realised diversity stays temporarily unchanged
what is traditional BEF thinking
higher biodiversity enhances ecosystem functioning through:
Complementarity effect – when species exploit resources in unique non overlapping ways – can be spatially, temporally or through distinct resource types.
Selection effect - the more species more likely that there will be high yield species/high productivity – increases chance of the ‘super-performance’
Facilitation – where one species helps another often by modifying the environment to reduce stress or enhance resource availability
