Biodiversity and Ecosystem Function

Vocabulary flashcards based on lecture notes about biodiversity, ecosystem function, and related concepts.

Biodiversity

• The variability of all living organisms from all sources

• Willis and Gillson, 2007

Alpha diversity

• The number of species in a specific location.

• Dornealas et al., 2014

Beta diversity

• How different communities are between places.

• often over a small distance, between habitats

• Dornealas et al. 2014

Gamma diversity

• the total species richness of a large geographic area - from ecological communities to entire biomes/ continents

• reflects combined influences of alpha and beta diversity

• Lomolino et al., 2017

Why is biodiversity important ?

• Ecosystem stability

• Without biodiversity humans struggle

• Lomolino et al., 2017

• number of green spaces are related to mental health

• the more species in park the less hospitalisations due to mental health

• Methrost et al., 2021

Ecosystem function

• The result of interactions between organisms.

• biodiversity increases ecosystem function

• more species - the better the species get in growing

• becoming more efficient in using the resources in Niches

• becoming more complementary

• efficiency increases - redundancy decrease

• Reich et al., 2012

Biodiversity does not always increase plant productivity

• Biodiversity loss at regional scales may effect ecosystem functioning

• ecosystem functioning was higher in patches with the lowest realised diversity

• There is a point which all species will die out

• Hagan et al., 2021

Why is ecological complexity important ?

• more taxa present that support the same function = increased redundancy

• higher diversity of taxa that support different functions = increased functional uniqueness

• Wagg et al., 2019

Microbiome diversity and microbial network complexity positively influenced several ecosystem functions

• greater microbial richness = greater complexity + greater association among taxa that support several functions

• we loose complexity, we loose functions

• Wagg et al., 2019

Case study for complexity over time

• recovering meadows in the Netherlands

• complexity and function increase through time

• soil networks had more and stronger interactions = more efficient carbon use

• Morriën et al. 2017

Pulse disturbance

• A disturbance that happens once and then disappears

• Lomolino et al., 2017

Press disturbance

• A disturbance that stays through time.

• Lomolino et al., 2017

Examples of disturbance

• wildfires, storms, floods, volcanic eruptions

• Begon and Townsend, 2021

Impact of disturbances

• Can open up gaps for new species to colonise and thrive

• some cases it prevents one species from dominating - maintains a diverse range of species - allows inferior species to colonise

• after a disturbance pioneer species arrive

• Begon and Townsend, 2021

• E.g. Atlantic forest in Brazil was flooded

Resistance

• Ability to withstand disturbance.

• most disturbance combination of press and pulse

• Lomolino et al., 2017

Robustness

• How much a species changes after a disturbance

• Lomolino et al., 2017

Biodiversity increases ecosystem stability, but not resilience

• Ecosystems with better diversity are able to overcome disturbance better

• Greater chance of having species with traits that are able to adapt to change

• Biodiversity stabilises ecosystem productivity to things such as climate events

• over time - ecosystems more stable

• McCann, 2000

Latitude and climate

• increase in species from the poles to the tropics

• temperatures are higher and precipitation is greater at lower latitudes

• needed for species growth + survival - more energy here

• e.g. troical diversity among mammals die to higher levels of fruit-eating lifestyle

• Cox and Moore, 2019

• Diagram from Rahbek et al., 2019

Elevation and climate

• decrease of species richness with elevation

• high elevation communities occupy small areas

• declining temperatures - less energy - harder for growth

• high elevations - moisture os frozen + unavailable

• diversity increases as altitude increases, reaches a peak - then decreases

• e.g. Mount Kinabalu - distance peak

• Begon and Townsend, 2021

Biodiversity hotspots

• areas that are extremely rich in species

• E.g. tropical rainforests, coral reefs and islands

• 25 hotspots

• land surface area = 1.4 %

• Low-latitude concentration of hotspots

• Diversity not evenly spread over globe

• Lomolino et al., 2017

Factor influencing biodiversity - Productivity

• species locate where conditions and resources are appropriate

• plants - productivity depends on nutrients or conditions + solar radiation

• higher productivity is linked to wider resources

• there are occasions of high productivity and low species richness

• high productivity —> high pop growth —> extinction of some species present

• species richness lower in extreme environments

• Begon and Townsend, 2021

Factor influencing biodiversity - Area / Physical barriers

• environments that are heterogeneous can accommodate new species

• as wider variety of microhabitats + microclimates

• Environmental temperature regimes - serve as barriers

• physical barriers - prevent spread of an organism e.g. mountains etc

• climatic and biological barriers e.g. geology and soil chemistry + competition

• Cox and Moore, 2019

Factor influencing biodiversity - Competition

• Biotic interactions can constrain distributions within a range

• organisms that share the same resource compete with each other can suffer from reduced growth, survival and reproduction

• exploitative competition - individuals use up resources and make them unavailable to others

• interference competition - individuals use aggressive dominance to deny others access to resources

• predation - when one organism kills another

• Lomolino et al., 2017

Spatial scale

• Local scale - species interactions - big importance

• Landscape scale - landscape configuration e.g. connected corridors etc

• Global scale - climate, biogeography etc

• diagram - Willis and Whittaker, 2002

Temporal scales

• may be predictable and unpredictable

• predictable - allows specialised adaptation

• unpredictable changes = disturbance

• communities are disturbed in extended timescales

• Begon and Townsend, 2021