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Glossary: O is for ... old organic order.
by Ariadne Unst
Glossary of O...
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- O horizon (n.)
- The soil horizon above
the A horizon.
- old growth (n.)
- Old-growth or ancient forests are forest lands that have not been
harvested or in any other way altered by people.
Of the estimated 2
million acres of coast redwood forest shortly after the arrival of the
Europeans, less than 4% are now uncut.
An old-growth stand is usually well
past the age of maturity as defined by the culmination of mean annual
increment. It often exhibits characteristics of decadence. Example: low growth
rates, dead and dying trees, snags, and down woody material. The stands
usually contain large-diameter trees relative to species and site potential,
multi-layered canopies, a range in tree-diameter sizes, and the presence of
Some documents specify a lower limit on size; for
example Michael Barbour et al. in Coast
Redwood: A Natural and Cultural History state that old-growth
redwoods exceed 200 feet high and 40 inches in diameter.
- open (adj.)
- Uncongested and open organization of flowers in an
- opposite (adj.)
that lie in pairs on axis.
Uncongested and open organization of flowers in an
- order (n.)
- A taxonomic category ranking below a class and above a
- organic soils layers (n.)
- L-layer--Freshly fallen or only slightly decomposed leaves, twigs,
flowers, fruit, and bark lying on the soil surface.
- F-layer--Zone of active organic matter fermentation.
- H-layer--Humidified zone. The more or less stable fraction from the
decomposed soil organic material. Generally, it is amorphous, colloidal, and
- organism (n.)
- An individual member of a species. A
single biological entity.
- ovary (n.)
- The basal portion of a
where germinated cells develop into seeds.
Some plants have a
and some have an
- ovate (adj.)
- Plump like a longitudinal section of a hen's egg;
broad end basal.
- ovule (n.)
- The body (inside the ovary) that develops into the seed.
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