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mtedals, by carbon dioxiae produoed by the rwts and by
the action of soil micro-organism is reviewed in Lubz 8e
Chandler (I 946). Voigt (I 965) and Wed, Davey & Cook
(1969) give further det~5ls;
Ons of the mnin functions of roots is absorption of water
and nubdents from the soil. The wcorhiaal f'unej. growing
in and around the root tissues helps the plant h the absorptian
of nutrients, particularly phosphorma. bhen a root dies or is
killed by felling of the tTee the organic matter, it cantahs
is slowly deoomposed by the joint action of ad1 baoteria,
hgi md soil animals and the contained nutrients are released
alowly hto the soil, The presence of root chamnels 5n soil
re&ers the latter more permeable to air and water whereas
organic mtter from root decomposition helps to maintain the
hwa level throughout the soil profile. These effeota are
par*t;icUrly important in an area such as the W Dis tr3ot
where the high minfaI.1 tencla to Bach the soil of nutrients,
and deep-burrowing earthworms are often abserrt beoause of hi&
soil a-ty.
a) Litter'
Utter, the fallen dead branches, le~ves, flowers and frufta,
acts as a blanket or: tho soil surPace protecting the underlStjng
soil and the roots an& soil organisms it contaim againat
extremes of tempemture, direot insolation, and the direct
impact of rai~ and restrict jng eveporntion *om the soil.
The nutdents in litter can only beoome available to plants
by deoompositian of the litter under the influence of
numerous dZffeerent types of soil arganisms.