Nonlinear Dynamics

The intrinsic predictability of ecological time series and its potential to guide forecasting

Successfully predicting the future states of systems that are complex, stochastic and potentially chaotic is a major challenge. Model forecasting error (FE) is the usual measure of success; however, model predictions provide no insights into the …

Quantitative argument for long-term ecological monitoring

Although it seems obvious that with more data, the predictive capacity of ecological models should improve, a way to demonstrate this fundamental result has not been so obvious. In particular, when the standard models themselves are inadequate (von …

Predicting coastal algal blooms in southern California

The irregular appearance of planktonic algae blooms off the coast of southern California has been a source of wonder for over a century. Although large algal blooms can have significant negative impacts on ecosystems and human health, a predictive …

Stock assessment and end-to-end ecosystem models alter dynamics of fisheries data

Although all models are simplified approximations of reality, they remain useful tools for understanding, predicting, and managing populations and ecosystems. However, a model’s utility is contingent on its suitability for a given task. Here, we …

Empirical Dynamic Modeling

Inferring system dynamics from time series

Forecasting

Predicting the future state of ecosystems.

Predicting the future in a nonlinear world

Equation-free mechanistic ecosystem forecasting using empirical dynamic modeling

It is well known that current equilibrium-based models fall short as predictive descriptions of natural ecosystems, and particularly of fisheries systems that exhibit nonlinear dynamics. For example, model parameters assumed to be fixed constants may …

Causal feedbacks in climate change

The statistical association between temperature and greenhouse gases over glacial cycles is well documented[1], but causality behind this correlation remains difficult to extract directly from the data. A time lag of CO_2 behind Antarctic …

Complex dynamics may limit prediction in marine fisheries

Complex nonlinear dynamics in marine fisheries create challenges for prediction and management, yet the extent to which they occur in fisheries is not well known. Using nonlinear forecasting models, we analysed over 200 time series of survey …