Ecology and Changing Environments - Functional Groups & Environmental Change
Plant Functional Types in Biome Type Models
- Equilibrium biogeography models predict biome distribution using plant functional types.
- Models predict equilibrium distribution and biogeochemistry (transfer of materials).
- Simulations compare observed vs. simulated biome distributions under environmental changes.
Biome3
- Predicts net primary productivity or leaf area index (LAI) based on the environment.
- LAI measures leaf area per unit area of earth's surface.
- Uses seven plant functional types (e.g., tropical broadleaf evergreens, temperate boreal conifers).
- Attributes: leaf persistence, root fraction in upper soil, photosynthetic pathway, stomatal conductance.
Biome4
- Coupled biogeography and biogeochemistry model with more functional types.
- Incorporates incoming radiation, atmospheric CO2, climate, and soil characteristics.
Testing Biome Models
- Pollen records used to infer past vegetation.
- Pollen cores from sedimentary deposits identify pollen types (grasses, conifers, broadleaves).
- Comparing model predictions to pollen-inferred vegetation from 6,000 years ago (warmer period) to test model accuracy under different climatic conditions.
Freshwater Invertebrates
- Used for bio-monitoring due to diversity and varying environmental responses.
- Macroinvertebrate sampling indicates waterway health.
- Study predicts climate change impacts on temperate European regions, expecting them to become more like Mediterranean regions.
Predictions Based on Traits
- Predictions made about how traits (e.g., body size, dispersal) will be affected by climate change.
- Small-bodied organisms expected to be more prominent in Mediterranean climates due to short life cycles.
- Active aerial dispersal is expected in Mediterranean systems due to intermittent water flow.
- Predictions evaluated by comparing macroinvertebrate traits in Mediterranean vs. temperate sites.
- Examines how plant traits relate to grazing across the globe.
- Based on 197 studies, considers traits like life history, canopy height, and habit architecture.
- Annual life histories often increase with grazing, perennials decrease.
- Context dependence: dry regions with short grazing history show different patterns.
Urbanization and Plant Traits
- Studies whether urban floras share common characteristics across cities.
- Analyzes extinction data and plant traits from 11 cities.
- Taller plants and heavier-seeded species more likely to persist in urban environments.
Scaling Traits to Ecosystem Function
- Aims to scale from individual species traits to community-level changes to ecosystem function.
- Environmental change affects species differently based on their traits, influencing community structure and ecosystem functioning.
- Concordance between functional response and effect groups influences ecosystem change magnitude.
Bumblebees and Pollination
- Agricultural intensification impacts bee communities and pollination.
- Larger-bodied bees, which are more effective pollinators, face higher extinction risk.
CO2 Enhancement and Nitrogen Cycling
- Examines whether enhanced CO2 leads to greater nitrogen cycling.
- Leaf nitrogen influences biomass response to elevated CO2.
- Soil nutrient cycling is better predicted by total plant biomass rather than leaf nitrogen content.
Population Dynamics Modeling
- Transition matrix modeling uses demographic attributes (fecundity, growth, survivorship).
- Predicts species responses to change, requiring dynamics.
- Population dynamics can be modeled with transition matrix modeling.
- Projects the rate of vital attribute replacement sequence and depends upon logical deductive functional groups.
Transition Matrix
- Life history stages (seedlings, juveniles, adults) and transitions between them.
- Transition matrix represents stasis (staying in the same stage), growth (moving to the next stage), and fecundity (reproduction).
- Matrix multiplication used to project population changes over time, incorporating disturbances.