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Digital terrain model (DTM) A gridded dataset containing the absolute elevations of the terrain with built objects and vegetation removed or data describing
the bare terrain surface (without buildings, vegetation, etc.).
Dimensions of biodiversity A term referring to the different aspects of biodiversity—including taxonomic diversity, phylogenetic diversity, functional diversity,
and spectral diversity—that can be applied at different scales (including alpha,
beta, and gamma diversity).
Direct/indirect species detection directly observing species presence or
composition/inferring species presence or composition based on correlated
measurements.
Directional scale See angular scale.
Discrete return system in the context of LiDAR measurements, instrumentation
that records individual points (representing peaks in the leading edge) in the
returning signal from a transmitted laser pulse from (c.f. full waveform).
Dispersal ability The capacity of organisms to move themselves or their propagules and offspring from one location to another.
(Dis)similarity coefficient A measure or index of the similarity (or difference)—
using any number of distance-based or other methods—between two objects,
variables, or samples, for example, ecological communities. Dissimilarity and
similarity coefficients are often used in multivariate analyses, including ordination methods, cluster analysis, multidimensional scaling, principal components analysis, etc. Common dissimilarity metrics include Euclidean distance,
Manhattan distance, covariance, correlation, and Bray-Curtis.
Distance decay Describes—often mathematically—the effect of distance on
interactions of the components in a study system, such that the decline in the
interaction of components between two locations is a function of the distance
between them.
Diversity Variation in characteristic or feature of interest. See also phylogenetic
diversity, structural diversity, taxonomic diversity, functional diversity, geodiversity, optical diversity, spectral diversity, phylogenetic diversity, structural diversity, taxonomic diversity, alpha diversity, beta diversity, and gamma diversity.
Diversity metrics A broad array of mathematical formulae for calculating biodiversity within a given spatial extent based on biological entities (individuals,
species, functions, groups) that variously consider numbers, abundance, and distribution. Many are related to metrics of information content or entropy.
Dominant species The most abundant in terms of biomass, cover, or stem density
in a community, ecosystem, or landscape. Developed most clearly by E. Lucy
Braun for use in characterizing forest types in North America.
Double bounce Reflection of a radar signal from one surface and then immediately from a second perpendicular surface such that most or all of the signal
returns to the antenna.
Downscaling A general procedure for taking information at broad spatial scales
to make predictions, or to infer states and processes, at finer scales (c.f. upscaling), e.g., interpolating from coarse to fine pixel or grain sizes.
Drone See unmanned aerial vehicle (UAV).
Glossary
Digital terrain model (DTM) A gridded dataset containing the absolute elevations of the terrain with built objects and vegetation removed or data describing
the bare terrain surface (without buildings, vegetation, etc.).
Dimensions of biodiversity A term referring to the different aspects of biodiversity—including taxonomic diversity, phylogenetic diversity, functional diversity,
and spectral diversity—that can be applied at different scales (including alpha,
beta, and gamma diversity).
Direct/indirect species detection directly observing species presence or
composition/inferring species presence or composition based on correlated
measurements.
Directional scale See angular scale.
Discrete return system in the context of LiDAR measurements, instrumentation
that records individual points (representing peaks in the leading edge) in the
returning signal from a transmitted laser pulse from (c.f. full waveform).
Dispersal ability The capacity of organisms to move themselves or their propagules and offspring from one location to another.
(Dis)similarity coefficient A measure or index of the similarity (or difference)—
using any number of distance-based or other methods—between two objects,
variables, or samples, for example, ecological communities. Dissimilarity and
similarity coefficients are often used in multivariate analyses, including ordination methods, cluster analysis, multidimensional scaling, principal components analysis, etc. Common dissimilarity metrics include Euclidean distance,
Manhattan distance, covariance, correlation, and Bray-Curtis.
Distance decay Describes—often mathematically—the effect of distance on
interactions of the components in a study system, such that the decline in the
interaction of components between two locations is a function of the distance
between them.
Diversity Variation in characteristic or feature of interest. See also phylogenetic
diversity, structural diversity, taxonomic diversity, functional diversity, geodiversity, optical diversity, spectral diversity, phylogenetic diversity, structural diversity, taxonomic diversity, alpha diversity, beta diversity, and gamma diversity.
Diversity metrics A broad array of mathematical formulae for calculating biodiversity within a given spatial extent based on biological entities (individuals,
species, functions, groups) that variously consider numbers, abundance, and distribution. Many are related to metrics of information content or entropy.
Dominant species The most abundant in terms of biomass, cover, or stem density
in a community, ecosystem, or landscape. Developed most clearly by E. Lucy
Braun for use in characterizing forest types in North America.
Double bounce Reflection of a radar signal from one surface and then immediately from a second perpendicular surface such that most or all of the signal
returns to the antenna.
Downscaling A general procedure for taking information at broad spatial scales
to make predictions, or to infer states and processes, at finer scales (c.f. upscaling), e.g., interpolating from coarse to fine pixel or grain sizes.
Drone See unmanned aerial vehicle (UAV).
Glossary