Task: Class Definition Understanding (ontology: Earth_Environment/SWEET)

Which of the following definitions best describes 'alpine tundra'?

A. Gelisols are soils of very cold climates which are defined as containing permafrost within two metres of the soil surface. The word the concept comes from the Latin gelare meaning to freeze, a reference to the process of cryoturbation that occurs from the alternating thawing and freezing characteristic of Gelisols.
B. A the concept is an intrusive igneous rock body that crystallized from a magma slowly cooling below the surface of the Earth. Plutons include batholiths, dikes, sills, laccoliths, lopoliths, and other igneous bodies. In practice, ‘the concept’ usually refers to a distinctive mass of igneous rock, typically kilometers in dimension, without a tabular shape like those of dikes and sills. Batholiths commonly are aggregations of plutons. The most common rock types in plutons are granite, granodiorite, tonalite, and quartz diorite. [Wikipedia]
C. the concept is an ecozone that does not contain trees because it has high altitude. the concept occurs at high enough altitude at any latitude on Earth. the concept also lacks trees, but the lower part does not have permafrost, and alpine soils are generally better drained than permafrost soils. the concept transitions to subalpine forests below the tree line; stunted forests occurring at the forest-tundra ecotone are known as Krummholz. the concept occurs in an alpine zone
D. A constituent that occupies space between individual grains of a consolidated sedimentary rock, and binds the grains together as a rigid, coherent mass; it may be derived from the sediment or its entrapped waters, or it may be brought in by solution from outside sources. Material is usually chemically precipitated (Jackson, 1997, p. 103). Distinguished from matrix by clearly secondary origin and generally monomineralic charactera

Answer: the concept is an ecozone that does not contain trees because it has high altitude. the concept occurs at high enough altitude at any latitude on Earth. the concept also lacks trees, but the lower part does not have permafrost, and alpine soils are generally better drained than permafrost soils. the concept transitions to subalpine forests below the tree line; stunted forests occurring at the forest-tundra ecotone are known as Krummholz. the concept occurs in an alpine zone