Biodiversity And Ecosystem Functioning Flashcards
(31 cards)
What is BEF research?
Study of how biodiversity (species richness/composition) influences ecosystem processes (productivity, nutrient cycling, stability).
How did the 1990s change views on biodiversity?
Shift from seeing biodiversity as environmentally determined to recognizing it as a driver of ecosystem function.
Why was early BEF research controversial?
Some misinterpreted it as challenging abiotic controls (e.g., climate), but it complements them.
Name two landmark BEF syntheses.
Cardinale et al. (2012, Nature); Loreau et al. (2001, Science).
How does complementarity enhance ecosystem function?
Species partition niches (e.g., root depths) or facilitate each other (e.g., nitrogen fixers).
Why do diverse communities often outperform monocultures?
Higher chance of including a ‘high-performing’ species (e.g., fast-growing plant).
Give an example from marine systems.
Deep-sea sea cucumbers divide food by pigment, reducing competition.
What did the 11-year experiment demonstrate?
Diverse plots resisted drought better and recovered faster (higher resilience).
What were two limitations of early BEF experiments?
(1) Tested few species (≤16); (2) Ignored multi-trophic interactions.
How did the Jena Experiment address critiques?
500 plots with 1–60 plant species; showed complementarity dominated in mature systems.
Why is Ythan Estuary a model BEF system?
Compact (8 km), shows bioturbation’s role in nutrient cycling.
How was BPc (Bioturbation Potential) calculated?
Combined species abundance, biomass, mobility, and feeding traits.
Contrast marine and terrestrial BEF patterns.
Marine: Small bioturbators drive large processes; Terrestrial: Plant diversity dominates.
How does BEF support polycultures?
20–30% higher productivity; better resource use (e.g., nitrogen retention).
What were the key findings of the Climate Change Experiment?
Richness boosted function, but high CO₂ + 18°C caused collapse, even with diversity.
How does current extinction loss compare to background rates?
~1,000x faster (1 species/20 mins; 27,000/year).
Why is random extinction loss unrealistic?
Specialists/large species disappear first (e.g., elephants, deep-sea corals).
What did Bracken’s Seaweed Study show about species combinations?
Some experimentally possible mixes don’t occur naturally.
Why does function plateau at high richness?
Niche overlap reduces unique contributions (e.g., >10 plants add minimal nitrate retention).
Quantify marine bioturbation’s global impact.
30,000 km³ sediment mixed daily (~12.5x Everest’s volume).
How can BEF guide conservation policy for protected areas?
Prioritize functionally unique species (e.g., keystone engineers like beavers).
What’s a BEF-based restoration strategy?
Use diverse seed mixes to enhance resilience (e.g., Minnesota grasslands).
How is BEF applied in offshore wind farms?
Assess impacts on benthic communities to minimize bioturbation loss.
Give a BEF example in urban ecosystems.
Diverse green roofs improve stormwater retention and cooling.