537
Elevational range The absolute difference (maximum minus minimum) between
elevation at two sites or sample units.
Ellenberg indicator values A classification procedure for Central European
plants according to their ecological “behavior” and botanical properties, first
described in detail by Heinz Ellenberg in the mid-1970s.
Emissivity A measure of the degree to which an object’s surface emits thermal
energy (expressed relative to a blackbody of the same temperature).
Empirical line correction A method for correcting atmospheric influences on
remotely sensed data to estimate surface reflectance using calibrated or stable
ground targets (a form of vicarious calibration).
Empirical model A mathematical model derived directly from observable data,
often using statistical methods (as opposed to first principles or conceptual
mechanisms) to derive a generalized representation of a process (c.f. mechanistic
model or process model).
Empirical-statistical model a model derived from applying statistics to data (c.f.
mechanistic model).
Endmembers Spectral signature “types” selected to represent different categories of surface features, such as different vegetation classes or scene components (e.g., forest, grassland, soil, standing water), phylogenetic groups (e.g.,
plant families, species), or vegetation states (e.g., alive, dead). Can also represent
spectral types determined mathematically, e.g., from imaging spectrometry.
Endemism Degree of spatial restriction of a species. A species is endemic to a
place if it only exists in that location (e.g., an island, mountain, country, region).
Ensemble classification A classification method using multiple learning algorithms to obtain better performance than use of a single learning algorithm.
Environmental filtering The process by which organisms cannot persist in a
local environment because they lack the necessary physiological tolerances to
survive or reproduce there. In the strict sense, environmental filtering refers only
to abiotic factors that prevent persistence rather than biotic factors, such as competition or pest or pathogen pressure. In contrast, environmental sorting encompasses both abiotic and biotic factors.
Environmental heterogeneity The variability of environmental entities—such as
topography, hydrology, soils, and climate—in space and time.
Environmental sorting The process by which species assemble into particular
ecological niches, defined by biotic and abiotic variables, based on their functional characteristics and environmental tolerances. Environmental sorting is a
consequence of both abiotic factors (such as light, nutrient and water availability,
or temperature) and biotic factors (such as herbivory, pathogens, competition,
pollination, etc.).
Environmental space The suite of environmental conditions at a given space
and/or time.
Epidermis The outermost layer of cells on plant organs that have not undergone
secondary growth, e.g., the “skin” of the surfaces of the leaves or other primary
plant organs.
Epigenetic Heritable changes in gene expression patterns that do not involve
alterations in the DNA sequence. An example is the addition of methyl groups
Glossary
Elevational range The absolute difference (maximum minus minimum) between
elevation at two sites or sample units.
Ellenberg indicator values A classification procedure for Central European
plants according to their ecological “behavior” and botanical properties, first
described in detail by Heinz Ellenberg in the mid-1970s.
Emissivity A measure of the degree to which an object’s surface emits thermal
energy (expressed relative to a blackbody of the same temperature).
Empirical line correction A method for correcting atmospheric influences on
remotely sensed data to estimate surface reflectance using calibrated or stable
ground targets (a form of vicarious calibration).
Empirical model A mathematical model derived directly from observable data,
often using statistical methods (as opposed to first principles or conceptual
mechanisms) to derive a generalized representation of a process (c.f. mechanistic
model or process model).
Empirical-statistical model a model derived from applying statistics to data (c.f.
mechanistic model).
Endmembers Spectral signature “types” selected to represent different categories of surface features, such as different vegetation classes or scene components (e.g., forest, grassland, soil, standing water), phylogenetic groups (e.g.,
plant families, species), or vegetation states (e.g., alive, dead). Can also represent
spectral types determined mathematically, e.g., from imaging spectrometry.
Endemism Degree of spatial restriction of a species. A species is endemic to a
place if it only exists in that location (e.g., an island, mountain, country, region).
Ensemble classification A classification method using multiple learning algorithms to obtain better performance than use of a single learning algorithm.
Environmental filtering The process by which organisms cannot persist in a
local environment because they lack the necessary physiological tolerances to
survive or reproduce there. In the strict sense, environmental filtering refers only
to abiotic factors that prevent persistence rather than biotic factors, such as competition or pest or pathogen pressure. In contrast, environmental sorting encompasses both abiotic and biotic factors.
Environmental heterogeneity The variability of environmental entities—such as
topography, hydrology, soils, and climate—in space and time.
Environmental sorting The process by which species assemble into particular
ecological niches, defined by biotic and abiotic variables, based on their functional characteristics and environmental tolerances. Environmental sorting is a
consequence of both abiotic factors (such as light, nutrient and water availability,
or temperature) and biotic factors (such as herbivory, pathogens, competition,
pollination, etc.).
Environmental space The suite of environmental conditions at a given space
and/or time.
Epidermis The outermost layer of cells on plant organs that have not undergone
secondary growth, e.g., the “skin” of the surfaces of the leaves or other primary
plant organs.
Epigenetic Heritable changes in gene expression patterns that do not involve
alterations in the DNA sequence. An example is the addition of methyl groups
Glossary