Development of a combined marine and terrestrial biodiversity indicator: research

11. Glossary of technical terms used in this report

Aichi targets: 20 time-bound, measurable targets adopted in the Strategic Plan for Biodiversity 2011-2020 in order to assess progress towards Convention on Biological Diversity goals.

Bayesian modelling: a statistical approach in which probability is used to represent all uncertainty within the model, both the uncertainty regarding the output but also the uncertainty regarding the input (aka parameters) to the model.

Biological records: validated records of species at a given location and time. Collected through a wide range of sampling approaches often without overarching design, and with varying resolutions (e.g. spatial). They are collated in a variety of ways, most notably by the Biological Records Centre (BRC) but also by a network of regional centres (Local Environmental Records Centres).

Confidence limits: the maximum and minimum values within which a value is believed to lie at a given level of probability. Often 95% is used to e.g. give the values either side of an indicator line within which the true value of the indicator is 95% likely to lie.

Demersal fish: species which live and feed on or near the bottom of water bodies (e.g. seas). Also referred to as groundfish.

Disaggregation: the analytical disassembly of categories that have been previously been combined together.

Generalised Additive Models: a class of Generalised Linear Model (see below) in which the usual linear relationships between the response and predictor variables are replaced by non-linear smooth functions

Generalised Linear Models: a flexible generalization of ordinary linear regression that allows for response variables that have error distribution models other than a normal distribution.

Geometric mean: a measure of average, which indicates the central tendency or typical value of a set of numbers by using the product of their values (as opposed to the arithmetic mean which uses their sum). Often used to calculate averages for measures of proportional change.

Indicandum: the subject to be indicated – in this case biodiversity.

Invasive species: an organism that causes ecological or economic harm in a new environment where it is not native – most often defined as a country in which it does not naturally occur.

Living Planet Index: a measure of the state of the world's biological diversity based on population trends of vertebrate species from terrestrial, freshwater and marine habitats.

Natural Capital: the stock of elements of nature (including living things, soil, air, water and geology) which directly or indirectly provide benefits for humans (often referred to as 'ecosystem services').

Occupancy-detection modelling: used to account for imperfect detection of organisms in surveys and to determine the probability of the true presence or absence of a species at a site.

Pelagic: relating to open marine waters e.g. pelagic fish, excluding zones near the bottom of the sea, so not including fish defined as demersal (see above).

Red list: an inventory of the conservation status of species, usually defining risk of extinction using a formal process governed by the IUCN (International Union for the Conservation of Nature), although alternative red-listing approaches do exist.

Smoothing: use of functions to remove minor fluctuations ("noise") in an ordered series to reveal underlying trends.

Weighting: the use of factors to increase or decrease the importance of given data points. Often used to address biases in sampling across different groups.