FRST90032 Ecosystems in a Changing Climate
The Complete Study & Assessment Guide · Semester 2 2026FRST90032 Overview
- Graduate coursework
- Semester 2 2026
- Climate and Ecosystem Science
- 4 concept chapters
The forest-climate overview distributes Semester 2, 2026 assessment across 3 rows weighted 10%, 25%, 65%. The current Week 1 subject overview identifies three assessment pieces and their weights.
- Weather varies inside a changing climate Separate short events from distributions that shift over decades
- Impact emerges from exposure and sensitivity Link the climate variable to a biological process and a vulnerable life stage
- Carbon dioxide changes leaf exchange Distinguish instantaneous photosynthesis from whole-ecosystem production
- A pool is not a flux Keep tonnes of carbon separate from tonnes per year
How FRST90032 is assessed
| Component | Weight | Format |
|---|---|---|
| Daily quizzes | 10% | Up to 12 LMS questions, two attempts, first attempt graded |
| Oral presentation | 25% | Ten-minute pre-recorded group presentation |
| Written assignment | 65% | 3,000 words across three smaller parts |
The current Week 1 subject overview identifies three assessment pieces and their weights. It does not state a hurdle in the captured assessment section; Canvas remains the authority for allocated topics, part instructions and current due dates.
Assessment structure
Forest-climate assessment weights follow the current Week 1 overview; Canvas controls allocated topics and part-level directions.
What FRST90032 covers
The scientific route moves from the energy imbalance to ecosystem exposure and response, isolates the conditional effects of elevated carbon dioxide, and closes by reconciling carbon pools with the fluxes that change them.
Climate Signals, Forcing and Uncertainty
Connect observed climate change to energy imbalance, drivers, models and risk statements.02Forest Impacts and Ecosystem Feedbacks
Examine exposure, sensitivity, adaptive capacity and the feedbacks generated by forest change.03Elevated Carbon Dioxide and Production
Interpret photosynthetic response through experiments and the resource constraints that limit persistence.04Carbon Pools, Fluxes and Accounting
Reconcile carbon stored in ecosystem compartments with gross and net transfers across a declared boundary.It does not state a hurdle in the captured assessment section; Canvas remains the authority for allocated topics, part instructions and current due dates. The scientific route moves from the energy imbalance to ecosystem exposure and response, isolates the conditional effects of elevated carbon dioxide, and closes by reconciling carbon pools with the fluxes that change them.
Weather describes atmospheric conditions over short periods; climate describes the distribution of those conditions over a longer reference interval. Climate change alters means, variability and extremes rather than prescribing every event. Compare like seasons, locations, variables and baselines. A climate signal appears in persistent distributional change supported across records, not in a single memorable anomaly.
Earth's climate responds to the balance between absorbed solar energy and outgoing infrared radiation. A positive radiative forcing reduces outgoing energy or increases absorption until warming restores balance. Identify the forcing agent, sign, spatial pattern and time scale. Greenhouse gases, aerosols, land-cover change and solar variation act through different radiative pathways.
Express each perturbation relative to a stated baseline and distinguish instantaneous forcing from the adjusted response after the stratosphere changes. Carbon dioxide, methane and other gases differ in atmospheric lifetime, absorption and interaction with biogeochemical cycles. Emissions alter concentration through source and sink processes. Keep stock emissions, annual flow and atmospheric concentration distinct.
Specify whether a comparison concerns near-term warming, long-term commitment or cumulative carbon. Name the accounting horizon and pulse-versus-sustained-emission convention before comparing gases, because each choice changes the policy meaning. Climate models encode physical processes on a resolved grid and parameterise smaller-scale phenomena.
Ensembles sample internal variability, initial conditions and scenario uncertainty. Evaluate whether a model reproduces relevant historical patterns, conserve the variable and scale of interest, and compare multiple models where structural uncertainty matters. Where a source publishes a stated ± range, preserve that interval and its units instead of replacing it with a naked point estimate.
Detection asks whether observed change exceeds expected internal variability. Attribution assesses the relative contribution of candidate forcings using observations, models and physical understanding. Compare fingerprints across space, season, altitude or variable, and test whether natural drivers alone reproduce the pattern. State confidence and alternative contributors.
An ecosystem impact depends on the magnitude and timing of exposure, organism or community sensitivity, and capacity to acclimate, adapt or move. Temperature alone rarely completes the chain. Specify the climate driver, duration, season, physiological process and response metric. Compare across species, age, soil and management where those conditions alter the mechanism.
Drought reduces water availability, heat raises atmospheric demand and fire consumes biomass while changing structure. Their coincidence or order can create effects larger than isolated stress. Follow soil moisture, vapour pressure deficit, stomatal response, tissue damage, mortality, fuel condition and regeneration. Lagged effects belong in the observation window.
Forests influence climate through carbon uptake and release, surface reflectivity, roughness and evapotranspiration. The net effect depends on biome, season, disturbance and time horizon. Compare biogeochemical and biophysical pathways on a common spatial and temporal boundary. Include the counterfactual land cover rather than treating forest presence as a universal baseline.
Elevated carbon dioxide can increase carboxylation and reduce stomatal conductance in many plants, potentially improving water-use efficiency. Scaling to ecosystems introduces respiration, allocation, turnover and competition. Separate leaf assimilation, gross primary production, net primary production and net ecosystem exchange. The sign and magnitude depend on which fluxes and pools are measured.
Specify whether the comparison is instantaneous, seasonal or cumulative, because identical percentages can refer to incompatible carbon quantities. Report leaf area, duration and allocation assumptions before scaling a chamber response to stand-level carbon storage.
Free-Air CO2 Enrichment experiments expose vegetation under field conditions while retaining weather, soil and community interactions better than small closed chambers. They test both initial response and persistence. Read treatment contrast with replication, duration, nutrient status, water supply and measured pool. Look for acclimation and allocation shifts rather than only the first-year mean.
Carbon pools are amounts stored in vegetation, dead wood, litter and soil at a time. Fluxes transfer carbon among pools or across the ecosystem boundary through photosynthesis, respiration, disturbance and export. Label every quantity with units, time basis and boundary. A stock change equals inflows minus outflows only after internal transfers are treated consistently.
Carbon accounting defines which land, gases, pools, activities and periods are included. Net claims change when harvested products, displaced activity, baseline growth and future disturbance are added. Draw the system boundary, identify the without-project trajectory and record each material transfer. Use consistent carbon dioxide or carbon units and avoid counting one benefit twice.
Worked application: Net carbon depends on boundary and counterfactual
- 1Declare the spatial boundary, period and response variable.
- 1Trace the physical or biological mechanism across each link.
- 1Match the comparison or treatment to the causal claim.
- 1Separate supported response from projection and report uncertainty.
Key terms
- Weather varies inside a changing climate
- Separate short events from distributions that shift over decades. Weather describes atmospheric conditions over short periods; climate describes the distribution of those conditions over a longer reference interval. Climate change alters means, variability and extremes rather than prescribing every event.
- Radiative forcing perturbs the energy budget
- Follow incoming sunlight, reflection and outgoing longwave radiation. Earth's climate responds to the balance between absorbed solar energy and outgoing infrared radiation. A positive radiative forcing reduces outgoing energy or increases absorption until warming restores balance.
- Greenhouse gases differ by lifetime and pathway
- Compare concentration, radiative effect and carbon-cycle response. Carbon dioxide, methane and other gases differ in atmospheric lifetime, absorption and interaction with biogeochemical cycles. Emissions alter concentration through source and sink processes.
- Models are controlled representations
- Use ensembles to explore mechanisms and conditional futures. Climate models encode physical processes on a resolved grid and parameterise smaller-scale phenomena. Ensembles sample internal variability, initial conditions and scenario uncertainty.
- Attribution compares worlds with and without forcing
- Move from observed change to a probabilistic causal statement. Detection asks whether observed change exceeds expected internal variability. Attribution assesses the relative contribution of candidate forcings using observations, models and physical understanding.
- Impact emerges from exposure and sensitivity
- Link the climate variable to a biological process and a vulnerable life stage. An ecosystem impact depends on the magnitude and timing of exposure, organism or community sensitivity, and capacity to acclimate, adapt or move. Temperature alone rarely completes the chain.
- Drought, heat and fire form compound stress
- Track hydraulic failure, carbon balance, fuels and recovery. Drought reduces water availability, heat raises atmospheric demand and fire consumes biomass while changing structure. Their coincidence or order can create effects larger than isolated stress.
- Forests feed back to climate
- Balance carbon storage with albedo, water and energy exchange. Forests influence climate through carbon uptake and release, surface reflectivity, roughness and evapotranspiration. The net effect depends on biome, season, disturbance and time horizon.
- Carbon dioxide changes leaf exchange
- Distinguish instantaneous photosynthesis from whole-ecosystem production. Elevated carbon dioxide can increase carboxylation and reduce stomatal conductance in many plants, potentially improving water-use efficiency. Scaling to ecosystems introduces respiration, allocation, turnover and competition.
- FACE experiments reveal conditional response
- Use open-air manipulation to test acclimation, nutrients and water. Free-Air CO2 Enrichment experiments expose vegetation under field conditions while retaining weather, soil and community interactions better than small closed chambers. They test both initial response and persistence.
- A pool is not a flux
- Keep tonnes of carbon separate from tonnes per year. Carbon pools are amounts stored in vegetation, dead wood, litter and soil at a time. Fluxes transfer carbon among pools or across the ecosystem boundary through photosynthesis, respiration, disturbance and export.
FRST90032 FAQ
Why must every ecosystem claim declare a spatial and temporal boundary?
Earth's climate responds to the balance between absorbed solar energy and outgoing infrared radiation. A positive radiative forcing reduces outgoing energy or increases absorption until warming restores balance. Label the driver, response variable, place and period before allowing evidence to travel across scales.
Carry the declared boundary into greenhouse gases differ by lifetime and pathway: compare concentration, radiative effect and carbon-cycle response.
What separates a climate signal from one memorable weather event?
Climate models encode physical processes on a resolved grid and parameterise smaller-scale phenomena. Ensembles sample internal variability, initial conditions and scenario uncertainty. Compare like seasons and baselines across a long record instead of treating an isolated anomaly as the distribution.
Carry the declared boundary into attribution compares worlds with and without forcing: move from observed change to a probabilistic causal statement.
How should an ensemble range change the wording of a projection?
An ecosystem impact depends on the magnitude and timing of exposure, organism or community sensitivity, and capacity to acclimate, adapt or move. Temperature alone rarely completes the chain. Preserve scenario, internal-variability and structural uncertainty instead of averaging them into false precision.
Carry the declared boundary into drought, heat and fire form compound stress: track hydraulic failure, carbon balance, fuels and recovery.
When can elevated carbon dioxide increase leaf exchange without increasing forest carbon?
Forests influence climate through carbon uptake and release, surface reflectivity, roughness and evapotranspiration. The net effect depends on biome, season, disturbance and time horizon. Trace assimilation through allocation, respiration, turnover and nutrient constraint before inferring a durable pool change.
Carry the declared boundary into carbon dioxide changes leaf exchange: distinguish instantaneous photosynthesis from whole-ecosystem production.
Which comparison reveals a compound drought, heat and fire effect?
Free-Air CO2 Enrichment experiments expose vegetation under field conditions while retaining weather, soil and community interactions better than small closed chambers. They test both initial response and persistence. Examine event order, hydraulic damage, fuel condition and recovery because the same averages can hide compound stress.
Carry the declared boundary into a pool is not a flux: keep tonnes of carbon separate from tonnes per year.
Why can a large carbon pool coexist with a small annual sink?
Carbon accounting defines which land, gases, pools, activities and periods are included. Net claims change when harvested products, displaced activity, baseline growth and future disturbance are added. Keep tonnes of stored carbon distinct from tonnes per year crossing the ecosystem boundary.
Carry the declared boundary into weather varies inside a changing climate: separate short events from distributions that shift over decades.
What belongs inside a defensible forest-carbon counterfactual?
Earth's climate responds to the balance between absorbed solar energy and outgoing infrared radiation. A positive radiative forcing reduces outgoing energy or increases absorption until warming restores balance. Draw the without-project trajectory and follow products, substitution, leakage, disturbance and time explicitly.
Carry the declared boundary into greenhouse gases differ by lifetime and pathway: compare concentration, radiative effect and carbon-cycle response.
How to prepare for the assessments
Keep a scale ledger for atmosphere, organism, stand, ecosystem and landscape, and never move between them without naming the mechanism. Use Climate Signals, Forcing and Uncertainty; Forest Impacts and Ecosystem Feedbacks; Elevated Carbon Dioxide and Production; Carbon Pools, Fluxes and Accounting to connect forcing, exposure, response, feedback and carbon accounting.
Annotate every quantity as stock, flux, rate, concentration or probability, with units and time basis. Sketch the counterfactual beside the observation and identify which treatment, model ensemble or historical record supports the comparison. Rework one claim under a different season, biome, disturbance sequence or nutrient constraint.
Preserve model spread and experimental duration rather than converting conditional evidence into a universal forest response. Before handing in assessment work, audit each arrow and boundary. A carbon total must reconcile transfers, while a projection must distinguish detection, attribution and scenario-dependent future change.
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