Glossary - Afforestation, Reforestation and Forest Restoration in Arid and Semi-arid Tropics - page 269

is equal to the negative logarithm of the effective hydrogen ion concentration in it,
i.e. hydrogen ion activity in gram equivalent per litre of the solution.

Phenology The periodic biological changes in plants in a given locality that are
correlated with the weather cycle, i.e. the seasons of a year.

Piece-rate wages Wages earned by persons doing piecework.

Piecework Work done by the piece and paid for at a set rate per unit.

Pitcher irrigation A form of drip irrigation wherein earthen pitchers with small
holes in bottom are buried into ground and then filled with water and sealed with
a diaphragm. Water gradually seeps into the soil around the roots, thus avoiding
evaporation losses.

Plant extractor A cylindrical barrel usually made of sheet of galvanised iron, with
an iron rod passing into interlocked seamed edges, used for potting of large plants.

Plant material The source or germ plasm from which plants are propagated or
raised. It can be seeds, seedlings, cuttings, stumps, or tissues.

Plant propagation Multiplication of plants from parent material such as seeds, stem
cuttings, grafts, buds, or tissue. Though a given species of plant can be propagated
by many of these methods, generally there are preferred propagation methods for the
various species.

Plantation A large group of trees planted in a tract of land, usually fenced or
delineated with a boundary. Planting of nursery-raised seedlings is necessary to
supplement the natural vegetation growth, especially in arid and semi-arid areas.

Plantation calendar A schedule prescribing the dates and periods for the different
activities involved in raising of a plantation.

Plantation journal A topic that serially records all the events, work done, and
expenses incurred on a plantation, usually in a pre-set format. The plantation journal
of a work is the original record and history of that particular work.

Plantation life cycle The cycle of raising of a plantation and its harvesting, and
then raising it again. Such a cycle need not involve removal of all the trees at the
same time. Usually, it is best to continually harvest trees by selection or by coppice
and to replant as and when required.

Plantation model A typical treatment plan with cost estimates designed to match
averaged site conditions of a specific type of terrain with specific goals of production
and services. Since it is drawn on assumptions relating to a hypothetical site, it must
always be suitably modified and adapted to the actual site when used in field as a
guide. A model affords a basis of projecting costs in a project, and for allocation of
annual budget while executing the project.
Planting out ⇒ Outplanting