Glossary - D
     
 
   
 

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D

DC: Abbreviation for the District of Columbia (United States).
DE: Abbreviation for the state of Delaware (United States).

Deep water: Open, non-vegetated aquatic habitats, extending beyond the littoral zone (shore or shallow water).

Degree of Threat: Code indicating the degree to which the element is threatened globally. Values include: A = Very threatened throughout its range communities directly exploited or their composition and structure irreversibly threatened by man-made forces, including exotic species; B = Moderately threatened throughout its range, communities provide natural resources that when exploited alter the composition and structure of the community over the long-term, but are apparently recoverable; C = Not very threatened throughout its range, communities often provide natural resources that when exploited alter the composition and structure over the short-term, or communities are self-protecting because they are unsuitable for other uses; D = Unthreatened throughout its range, communities may be threatened in minor portions of the range or degree of variation falls within natural variation; U = unknown.

Description: A brief description of the element. For more information see Classification of Plants

Desert: Extremely dry landscape, sparsely vegetated by widely spaced herbs, shrubs, or succulent tree-like plants; relatively barren substrate tends to dominate the aspect of the habitat. For more information see Classification of Ecological Communities.

Distribution Outside Canada and the United States (Ecological Communities and Systems): Countries outside Canada and the Unites States in which the Ecological Community or System occurs. The list for Alliances is calculated from the distribution of the Associations that are members of the Alliance. A "?" next to a nation means that the Ecological Community or System is suspected, but not confirmed, to occur there. Note: Absence of a nation cannot be interpreted as a definitive statement that the Ecological Community or System does not occur there.

Diurnal: Characteristically active during daylight.

Dominant
If checked, the designated component species (in the designated stratum/lifeform) is typically one of the most abundant species in stands of the ecological community.

Duration: The length of time an individual plant persists (e.g. annual, biennial, perennial).

Dwarf-Shrubland: For more information see Classification of Ecological Communities.

Dynamics: Summary of information on the important natural disturbance regimes, including comments on the type and length of disturbance cycles; successional status; and temporal dynamics for the Ecological Community or Ecological System.

 

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