Glossary - Afforestation, Reforestation and Forest Restoration in Arid and Semi-arid Tropics - page 277

Temporary nursery ⇒ Field nursery

Theodolite A surveyor's instrument for measuring horizontal and vertical angles
and usually provided with stadia hairs for tachymetrically reading distances as well.

Thinning Removal of alternate or selected trees in a stand to provide greater space
for growth of the remaining crop.

Tie A structural member that resists tension.

Tissue culture The plant propagation technique wherein body tissue of an adult
plant is made to grow in culture medium in vitro.

Topographic survey A survey undertaken to map out the main relief features of a
given tract of land.

Topographical survey sheets General purpose survey maps depicting the terrain,
its natural and man-made features including drainage lines, usually marking contours
at 10 to 20 m vertical interval. These maps form the categorical base for planning of
large projects. The scales of such maps may vary from 1:10,000 to 1:50,000.

Topping of plants Cutting of the top portion of plant shoot in nursery in order to
remove the dried up tops, or to stimulate growth in diameter.
Topsoil Surface soil including the organic matter in which plants have most of their
roots and which the farmer turns over in ploughing.

Total survey station A sophisticated equipment fitted with optical or radiomet-
ric capability and a computerised facility for automatic calculation and plotting of
positions of objects surveyed.

Transect walk A random walk cutting across an area with the aim of sampling the
area for its appraisal.

Transplanting To lift and reset a plant in another soil or situation.

Transpotting To transfer a plant from on pot or container to another.

Traverse A line surveyed across or around a plot of ground. The traverse line acts
as a base line for measuring and recording the details inside the plot of land, and also
determines the shape and area of the plot of land.

Treading Pressing the soil—with feet or otherwise—refilled in a pit during planting
operation, in order to make a firm contact between the soil and the roots. Treading
is critically important in naked root planting.

Treatment plan A plan laying down the different operations to be carried out and
structures to be made in a tract of land being considered for afforestation.

Tube well A small-diameter well drilled to obtain water. Also called a bore well or
simply a bore.
UGWR ⇒ Underground water reservoir