Instructor Notes

Why ecological forecasting?

Why do we need ecological forecasting?

  • Manage environmental change
  • Test how well we understand ecosystems

What are some of things we need to be able to make forecasts?

  • Models
  • Data


What influences our ability to forecast and how?

  • How well the factors driving the response are understood
  • How much data is available
  • Whether the forecast influences the thing being forecast
    • Are there examples in ecology where a forecast could influence the thing being forecast?

Forecasting, planning, and goals

What kinds of time-scales of forecasts do we want/need in ecology?

How might these different “forecasting horizons” influence our approaches to forecasting?

Determining what to forecast

How should we think about what to forecast in ecology?

  • Talk to those who need or are impacted by the forecast
  • Consider whether we have the data/models we need


What is forecasting?

  • Forecasting - probabalistic statement about the future using data assimilation.

The Luo et al. paper distinguishes between forecasting, prediction, projection & prognosis. What are the core differences?

  • Prediction - quantitative estimate of an unknown state. Can be about the future. Not necessarily accurate.
  • Projection - Possible future state resulting from a choice of future scenarios. Typically quantitative.
  • Prognosis - more subjective.
  • Note that these definitions vary across and even within disciplines
  • Definition of forecasting is much more narrow than most

Are these terms consistently used the two readings? In your experience more broadly?

  • Not really. Different fields, disciplines, and authors use them in different ways.


What is the distinction between point estimates and uncertainty?

  • Point estimates are the expected value or mean prediction
  • Uncertainty is the variability around that mean value, that describes the reasonable range of predictions.

Do most ecological forecasts include uncertainty estimates?

  • No

Why does estimating uncertainty matter?

  • Need to know how much to trust forecasts
  • What the realistic range of outcomes could be

Forecasting data and methods

What are the general types of models that can be used for forecasting and how do they differ?

  • Data-driven vs. Process modeling
    • What is a good example of cross-sectional forecasting in ecology?
    • What is a good example of time-series forecasting?
  • Within data-driven “Time series” vs. “Explanatory”

What are the different ways in which model parameters are determined?

  • Fixed
  • Fitted
  • How does this relate to process vs data-driven modeling?

When might these different approaches be most appropriate in ecology?

What are the different ways in which time can be incorporated into these models?

  • Explicitly
  • Implicitly (driving variables that change)
  • Not included

Basic steps

How do the “basic steps” of forecasting relate to ecological forecasting?

  • How well do you think our field does at each of these steps?
  • What can we do to improve on our current approaches?

Where do you think we are?

  • How good do you think we currently are at forecasting in ecology?
  • What does the history of weather forecasting tell you about how that might change?