531
Brownian motion model of evolution A model that depicts the evolution of a trait
as the accumulation of many random changes over time in a diffusion- like process.
At any point in time, a trait value is equally like to increase or decrease. The pace
at which those random changes accumulate is referred to as the rate of evolution.
Calibration Comparison of an instrument or measurement to a known standard,
often with known units (e.g., referenced to the US National Institute of Standards
and Technology).
Calibration data Data used to train models from imagery, including calibration
for atmospheric effects, georegistration, spectral resolution, and any retrieval of
interest.
Canopy The upper, aerial region of a plant or group of plants (e.g., tree crown or
crowns), often including other biological organisms (epiphytes, lianas, arboreal
animals, etc.). In ecology, the canopy often refers to the crown of a single plant,
whereas in remote sensing, it often refers collectively to the crowns of many
plants in a stand (e.g., trees in a forest).
Canopy cover Projection of tree crowns onto the ground divided by ground surface area.
Canopy structure The architecture of the aerial portion of a plant or plant stand
that influences the way plants interact with light and the reflectance patterns they
generate. Typical metrics include leaf area index, plant area index, leaf angle
distribution, branching structure, crown shape, etc.
Carbon cycling A critical biogeochemical cycle on Earth that governs how carbon
moves from living to nonliving chemical forms and involves transfers between
various “spheres” (biosphere, atmosphere, hydrosphere, lithosphere). The fast
carbon cycle (involving the biosphere) can be distinguished from the slow carbon cycle (involving the deep lithosphere and long-term geological storage).
Carbon flux Movement of carbon between Earth spheres (e.g., atmosphere, biosphere, and hydrosphere). Typically expressed as unit carbon per cross- sectional
area per unit time.
Carotenoids Plant tetraterpenoid pigments (a family of more than 1100 molecules), with hydrocarbon chains of conjugated double bonds ending in benzene
rings. They form red, yellow, and orange colors in leaves, fruit, and flowers (e.g.,
autumn leaf colors). They are grouped into two types: those without oxygen (the
carotenes) and those with oxygen (the xanthophylls). In plants, these molecules
help capture light energy for photosynthesis, or shield against excess energy, and
also act as antioxidants for photoprotection.
Cation-exchange capacity A measure of how many cations (atoms or molecules
with a positive charge) can be held on soil surface particles (typically negatively
charged) and thus are made available to plants.
Chemical phylogeny The evolutionary relationship of chemical traits.
Chemometrics A subdiscipline of chemistry aimed at extracting information from
chemical measurements in mixed environments using mathematical and statistical procedures that can be applied to spectroscopic data and remotely sensed
imagery.
Chlorenchyma A type of parenchyma cell in leaf mesophyll tissue that contains
chloroplasts and is photosynthetic.
Glossary
Brownian motion model of evolution A model that depicts the evolution of a trait
as the accumulation of many random changes over time in a diffusion- like process.
At any point in time, a trait value is equally like to increase or decrease. The pace
at which those random changes accumulate is referred to as the rate of evolution.
Calibration Comparison of an instrument or measurement to a known standard,
often with known units (e.g., referenced to the US National Institute of Standards
and Technology).
Calibration data Data used to train models from imagery, including calibration
for atmospheric effects, georegistration, spectral resolution, and any retrieval of
interest.
Canopy The upper, aerial region of a plant or group of plants (e.g., tree crown or
crowns), often including other biological organisms (epiphytes, lianas, arboreal
animals, etc.). In ecology, the canopy often refers to the crown of a single plant,
whereas in remote sensing, it often refers collectively to the crowns of many
plants in a stand (e.g., trees in a forest).
Canopy cover Projection of tree crowns onto the ground divided by ground surface area.
Canopy structure The architecture of the aerial portion of a plant or plant stand
that influences the way plants interact with light and the reflectance patterns they
generate. Typical metrics include leaf area index, plant area index, leaf angle
distribution, branching structure, crown shape, etc.
Carbon cycling A critical biogeochemical cycle on Earth that governs how carbon
moves from living to nonliving chemical forms and involves transfers between
various “spheres” (biosphere, atmosphere, hydrosphere, lithosphere). The fast
carbon cycle (involving the biosphere) can be distinguished from the slow carbon cycle (involving the deep lithosphere and long-term geological storage).
Carbon flux Movement of carbon between Earth spheres (e.g., atmosphere, biosphere, and hydrosphere). Typically expressed as unit carbon per cross- sectional
area per unit time.
Carotenoids Plant tetraterpenoid pigments (a family of more than 1100 molecules), with hydrocarbon chains of conjugated double bonds ending in benzene
rings. They form red, yellow, and orange colors in leaves, fruit, and flowers (e.g.,
autumn leaf colors). They are grouped into two types: those without oxygen (the
carotenes) and those with oxygen (the xanthophylls). In plants, these molecules
help capture light energy for photosynthesis, or shield against excess energy, and
also act as antioxidants for photoprotection.
Cation-exchange capacity A measure of how many cations (atoms or molecules
with a positive charge) can be held on soil surface particles (typically negatively
charged) and thus are made available to plants.
Chemical phylogeny The evolutionary relationship of chemical traits.
Chemometrics A subdiscipline of chemistry aimed at extracting information from
chemical measurements in mixed environments using mathematical and statistical procedures that can be applied to spectroscopic data and remotely sensed
imagery.
Chlorenchyma A type of parenchyma cell in leaf mesophyll tissue that contains
chloroplasts and is photosynthetic.
Glossary