Costing and Estimation ofWorks - Afforestation, Reforestation and Forest Restoration in Arid and Semi-arid Tropics - page 182

7.2.4 Silvipastoral Plantation (SPP)

These plantations are aimed at grazing lands and pastures. The model provides for
creation of grasslands dotted with trees to supplement yield of forage when grasses
are out of season. Seasons of lopping of trees and harvesting of grasses are staggered
in such a manner that forage is available throughout the year. This kind of arrangement
is crucial in arid areas where availability of fodder may be uncertain during a part of
the year. The principal work in this model is sowing of pelleted grass seeds on contour
furrows made by tractor-drawn disc ploughs. Table 7.10 shows model treatment plan
for a silvipastoral plantation of 50 ha.

7.2.5 Shelterbelt Plantation (SBP)

Planting trees in linear strips, or avenues—along roads, canals and railways, around
fields and habitations—poses special problems. Often the cost in such plantations, if
calculated per plant, is very high (6 mdeq, compared to 0.66 mdeq for RDF-500, for
example). Protection of the plants is difficult in spite of high cost of fencing. Species
range is wider, including broadleaf, ornamental, flowering, and exotic species which
are often more demanding in terms of maintenance and care. Size of such plantations
is often measured in row-kilometre (rkm) rather than in hectare because the cost is
directly proportional to the length of rows rather than to the block area. The number
of rows running parallel will affect the unit cost but this number is often limited and
ranges from three to ten because vacant land along roads, railways, or canalways
is often of limited width. The terrain is assumed to be flat and hence no in situ soil
and water conservation works are proposed except pit-saucers. These plantations are
likely to be irrigated plantations. The number of watering operations required will
depend upon the species and the climate. Table 7.11 presents a shelterbelt plantation
model with 300 plants per row-kilometre (i.e. an in-row spacing of 3 m between
plants).

7.2.6 Urban Area Plantation (UAP)

Planting trees in urban areas has many special features and characteristics that must be
taken into account. While the principles and practices of afforestation apply mutatis
mutandis , these plantations are often raised with different set of objectives. Choice
of species, level of fencing and protection, irrigation frequency, and absence of in
situ soil and water conservation structures distinguish urban area plantations from
other forest plantations. Block plantations raised in settlement areas—as forest parks,
woodlots, or tree groves—are an example of urban area plantations, although plan-
tations can also be raised as shelterbelts along roads in which case the SBP model
would be appropriate. Although the model UAP does not provide for in situ soil and