Ecological forecasting uses knowledge of physics, ecology and physiology to predict how ecological

populations Population typically refers to the number of people in a single area, whether it be a city or town, region, country, continent, or the world. Governments typically quantify the size of the resident population within their jurisdiction using a ...

communities A community is a social unit (a group of living things) with commonality such as place, norms, religion, values, customs, or identity. Communities may share a sense of place situated in a given geographical area (e.g. a country, village, to ...

, or

ecosystems An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syst ...

will change in the future in response to environmental factors such as

climate change In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to ...

. The goal of the approach is to provide natural resource managers with information to anticipate and respond to short and long-term climate conditions. Changing climate conditions present ecologists with the challenge to predict where, when and with what magnitude changes are likely to occur so that we can mitigate or at least prepare for them. Ecological forecasting applies existing knowledge of ecosystem interactions to predict how changes in environmental factors might result in changes to the ecosystems as a whole. One of the most complete sources on the topic is the book Ecological Forecasting written by Michael C. Dietze.

Methods

Ecologists shifted towards Bayesian methods starting 1990, when improvements in computational power allowed the use of more demanding computational statistics such as Hierarchical Bayes. This kind of analysis employs a

Bayesian Network A Bayesian network (also known as a Bayes network, Bayes net, belief network, or decision network) is a probabilistic graphical model that represents a set of variables and their conditional dependencies via a directed acyclic graph (DAG). Ba ...

that provides a probabilistic graphical model of a set of parameters, and can accommodate unobserved variables. A Bayesian structure is a probabilistic approach that is flexible for high-dimensional data, and allows ecologists to separate sources of uncertainty in their models. Forecasts can leverage

Bayes' Theorem In probability theory and statistics, Bayes' theorem (alternatively Bayes' law or Bayes' rule), named after Thomas Bayes, describes the probability of an event, based on prior knowledge of conditions that might be related to the event. For examp ...

and be iteratively updated with new observations using a process called

Data Assimilation Data assimilation is a mathematical discipline that seeks to optimally combine theory (usually in the form of a numerical model) with observations. There may be a number of different goals sought – for example, to determine the optimal state es ...

. Data Assimilation combines observations on different temporal and geographic scales with forecasts, all of which combine to provide more information than any one data source alone. Some ecologists have found this framework to be useful for ecological models as they often rely on a wide range of data sources.

Models

Ecological forecasting varies in spatial and temporal extent, as well as in what is being forecast (presence, abundance, diversity, production, etc.). * Population models may be used to generate short-term abundance forecasts using knowledge of

population dynamics Population dynamics is the type of mathematics used to model and study the size and age composition of populations as dynamical systems. History Population dynamics has traditionally been the dominant branch of mathematical biology, which has a ...

and recent environmental conditions. These models are used especially in

fisheries Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life; or more commonly, the site where such enterprise takes place ( a.k.a. fishing ground). Commercial fisheries include wild fisheries and fish farms, ...

and

disease A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that a ...

forecasting. * Species distribution models (SDMs) may be used to forecast

species distribution Species distribution —or species dispersion — is the manner in which a biological taxon is spatially arranged. The geographic limits of a particular taxon's distribution is its range, often represented as shaded areas on a map. Patterns of ...

(presence or abundance) over longer ecological time scales using information about past and projected environmental conditions across the landscape. ** Correlative SDMs, also known as climate envelope models, rely on statistical correlations between existing species distributions (range boundaries) and environmental variables to outline a range (envelope) of environmental conditions within which a species can exist. New range boundaries can then be forecast using future levels of environmental factors such as

temperature Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measured with a thermometer. Thermometers are calibrated in various temperature scales that historically have relied o ...

rainfall Rain is water droplets that have condensed from atmospheric water vapor and then fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides water f ...

, and

salinity Salinity () is the saltiness or amount of salt (chemistry), salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensio ...

from climate model projections. These methods are good for examining large numbers of species, but are likely not a good means of predicting effects at fine scales. ** Mechanistic SDMs use information about a species' physiological tolerances and constraints, as well as models of organismal body temperature and other biophysical properties, to define the range of environmental conditions within which a species can exist. These tolerances are mapped onto current and projected environmental conditions in the landscape to outline current and forecasted ranges for the species. In contrast to "climate envelope" approaches, mechanistic SDMs model the fundamental niche directly, and are therefore much more exact. However, the approach requires more information is also usually more time-consuming. *Other types of models may be used to forecast (or hindcast) biodiversity over evolutionary time scales. Palaeobiology modeling uses fossil and phylogenetic evidence of biodiversity in the past to project the trajectory of biodiversity in the future. Simple plots can be constructed and then adjusted based on the varying quality of the fossil record.

Forecasting examples

Biodiversity

Using fossil evidence, studies have shown that vertebrate biodiversity has grown exponentially through Earth's history and that biodiversity is entwined with the diversity of Earth's habitats.

Temperature

Forecasts of temperature, shown in the diagram at the right as colored dots, along the North Island of

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island coun ...

in the austral summer of 2007. As per the temperature scale shown at the bottom, intertidal temperatures were forecast to exceed 30 °C at some locations on February 19; surveys later showed that these sites corresponded to large die-offs in burrowing sea urchins.

Terrestrial Carbon Cycle

Forecasts of terrestrial carbon flux have been used to inform earth system models (ESMs). Some approaches use measurements from

eddy covariance The eddy covariance (also known as eddy correlation and eddy flux) is a key atmospheric measurement technique to measure and calculate vertical turbulent fluxes within atmospheric boundary layers. The method analyses high-frequency wind and scal ...

towers to predict carbon pools. In a 2015 paper, researchers found that carbon content in terrestrial ecosystems tend to converge to an equilibrium, and the rate of approach to equilibrium is intrinsically predictable.

References

External links

The Ecological Forecasting Initiative website
a grassroots initiative building a community of practice around ecological forecasting {{Authority control Environmental science Fisheries science