Glossary of biological terms: M
B C D
E F G
H I J
K L M
N O P
Q R S
T U V
W X Y
Massenerhebung effect. Depression of the
altitudinal limit of montane forest on small mountains compared with large ones.
See Grubb, P.J. 1971. Interpretation of the 'Massenerhebung'
effect on tropical mountains. Nature 229: 44-45.
mycelium. A network of
fungal hyphae (filaments) forming the vegetative
part of a fungus.
mycorrhiza (pl. mycorrhizae). A
mutualistic association between a fungus and
the roots of a higher plant. About 85% of vascular
plant species have mycorrhizae. The fungus benefits the plant by decomposing
organic matter in the soil and providing minerals to the plant, and the plant
benefits the fungus by providing sugars, amino acids, and some other organic
substances. Two main types occur: (1) Endomycorrhizae. The fungus
penetrates the cortical cells where it coils, or branches (the composite
branching hyphae in a cell are collectively called
an arbuscule); and (2) Ectomycorrhizae. The fungus forms a sheath around
the roots with hyphae growing inbetween the cortical cells.