Global change Ecology Flashcards
Biodiversity-Ecosystem Functioning (BEF)
BEF is the study of how the diversity of species within an ecosystem influences its overall functioning and the provision of ecosystem services.
How can eco-evolution mechanisms behind the BEF relationship be assesed?
with experiments
e.g. the “gold standard” Jena experiment (2002):
* grassland communities with different levels of plant diversity
* 60 species of 4 functional groups (grasses, small herbs, tall herbs, legumes
Now: Mesocosm experiments
Performance of ecosystems is measured by biomass production!
* all treatment combination of soil history (with/without)
* all treatment combinations of plant history (with/without)
* controll- treatment
* => Full factorial experiment
* Allowes to disentangle temporal effects (legag effects) of soil microbial communities from temporal effects on plants.
legumes: Hülsenfrüchte
Biodiversity experiment: the issue of realism
Experimental versus real-world communities
-> the results of biodiversit- ecosystem functioning experiments are realistic
Linking climate change and biodiversity loss
- climate change and biodiversity loss are two of the most pressing issues of the Anthropocene
- the two are interconnected -> means that resolving either issue requires consideration of the other
=> mutually supporting goals
5 drivers of biodiversity loss
Driver “pollution”: airborne reactive nitrogen deposition
-> burning of fossile energy
airborne: pollution in air -> rain down
NItrogen deposition leads to loss of species richness beacuse somme will outcompete the other (Nitrogen = fertilizer)
Driver “Invasive species”
IAS Invasive alien species
* have gained importance in the last years
* the spread rate depends on the number of founder populations
=> Importance to focuse on small founder populations!
Archeophytes
introduced before 1492
Neophytes
Introduced after 1492
Emerging viruses def.
- newly identified or previously known viruses
- that have increased in incidence, geographic range, or virulence
- pose a potential threat to human and animal health.
virulence: Fähigkeit eines Krankheitserregers, eine Erkrankung hervorrufen. Grad der Pathogenität.
Emerging infectious disease def.
- newly identified or re-emerging diseases that have recently appeared or experienced an increase in incidence
- posing a threat to public health
Viruses and environmetal change
Viruses can respond to a changing environment and are tehrefore susceptible to environmental changes such as climate change and land-use change.
-> cause epidemic and pandemic
-> is often a result of a zoonosis
What is Ebola?
- highly contaigous & life threatening fever desease
- out of 10 infected, 5-8 will die
- spread strategy in humans: hit and run
- Reservoir of Evola viruses: Bats (especially Fruit-Bats)
Symptoms of Ebola
- flu-like with skin rash
- Vomiting diarrhea, bleeding on and in the body “hemorrhaigic fever” -> fail of organs
Reservoir hosts
fruit- bats
* nocturnal, feed on fruits and nectar
* all three species show migratory & social behavior (Zugflughund)
=> Virus exchange, transregional & inter- species
Why does the Ebolavirus not kill the fruit- bats?
Theory 1: oldest mammals, therefore possible co evolution with virus -> viral spread strategy “Infect & persist”
Theory 2: Ability to fly requires enormous amount of energy & fast metabolism -> genetic altertions of the immune system, therefore particularly efficient to fight against virus
->
=> Both theories might be true
How does the curve of a virus outbreak look like?
Sigmoidal curve/ Saturational curve = dynamics of invasive species
* Abundancy commulative infections over TIme (achses)
* Pre-emergence -> Curve starts with Patient Zero -> exponentional increase -> Turning point:
-> 1. towards pandemic emergence
-> 2. Saturation (Commulative Infections)
or
-> 3. decrease back to zero
commulative = all persons ever infected
5 years till they developed a vaccine! Why covid so much faster?
- resticted to the global south
- we hav learned from ebola -> more understanding of the urgency
Why do more recent Ebola outbreaks tend to spiral out of control?
- higher population density
- humans travel a lot more
(like fruit- bats) - proximity to large cities
-> no self-limitation of epidemic
Why do more recent Ebola outbreaks tend to spiral out of control? Asynchronous globalization
- lack of education
- lack of trust in helathcare workers
- Cellphones enable rash communication about quarantine measures and vaccines
-> fatal mix: Poor level of education & use of modern communication undermines interventions
(even more dramatic in 2018 outbreak: attacks on aid workers complicated response)
Why do more recent Ebola outbreaks tend to spiral out of control? (add on)
- Low capacity for intervention -> Exceeding a threshold of infected persons
- Little expertise of Ebola -> Ebola causes fear
- Inadequate documentation -> “marginal diseases from Western perspective until 2014 => Time lag
Reasons for outbreak increase
- Land-use change: possibly increaseds the probability to direct contact and alternative jump- pathways
- CLimate change: outbreaks 1994-2002 increased during dry years at the end of the rainy season -> increased drought frequency may increase frequency of jump
=> HUMAN MADE
What to do?
We explore the jump and learn from it. (sensitive way)
-> much room for research e.g. high immunity in Gabon, Frequent contact with small amount of the virus
=> One Health (their helath = our health)