- DC resistivity
- The property of a material that resists the flow of electrical current.
- decomposer
- An organism that breaks down the bodies of dead plants and animals into simpler subsantces. These organisms mineralize organic matter, releasing inorganic components (the nutrients) to the environment, where they are again available for plants.
- depth hoar
- Cup shaped crystals (depth hoar, sugar snow) in which a faceted form continues to grow or mature in the presence of a steep temperature gradient. These crystals are heavily striated and can have cup or scroll shapes. The grains typically tend to be very large and are often significantly larger than most other grains that would be found in a snowpack (typical grain size can be more than 3 - 5 mm).
- diaspore
- Reproductive propagule (a seed or a fruit) of a plant
- dioecy
- All individuals (genets) are either entirely male or female.
- discontinuous permafrost
- Permafrost occurring in some areas beneath the exposed land surface throughout a geographic region where other areas are free of permafrost
- disturbance
- A relatively discrete event in time that disrupts the ecosystem, community or population structure and changes the resources, substrate availability or physical environment. (White & Pickett 1985)
- drainage
- The passage of excess water through the soil
- duripan
- Soil horizon cemented by silica which will not fall apart in water or hydrochloric acid. It may contain secondary cement, e.g. carbonates and iron oxides.
- dystric
- Having a base saturation (by 1M NH4O Ac) of less than 50 % in at least some part between 20 and 100 cm from the soil surface, or in a layer 5 cm thick directly above a lithic contact in Leptosols (Source: World Reference Base for Soil Resources (1998))
|
back
to top