Summary
Large areas of the Thal desert (between 30º-32 º N, 71º-72ºE) Punjab Province, Pakistan have suffered from over-gazing. Good forage grasses have disappeared and fodder trees have been heavily browsed by camels Camelus dromedarius and lopped to feed other livestock. Here attempts to re-establish native grasses and trees of fodder value on sand dunes, where failures followed usual reseeding methods, are summarised.
Grass planting: From 1963 to 1966, ‘tuft planting’ i.e. transplanting individuals (at spacings of 5 x 5, 10 x 5, and 10 x 10 ft) with at least a 23 cm long root system and 15 cm tall of two native perennial grasses, buffel grass (dhaman) Cenchrus ciliaris and sewan grass (karera) Elyonurus hirsutus, was undertaken on about 809 ha of loose sand dunes.
Tree planting: A tree planting technique was developed to establish trees including: Zizyphus jujuba (ber), Z.nummularis (mallah), Prosopis splicigera (jand) and Tamarix articulata. Rooted cuttings were grown in open ended, baked earthen tubes (30 cm long x 11 cm diameter x 1.3 cm thick) in the nursery. From July 1964 to April 1967, 100,000 cuttings/saplings (generally 45-60 cm tall) were planted out, most during the monsoon (July-August), but also during unusually good spring (March-April) rains in 1965.
Some were protected around the base (affording shelter from wind, sand abrasion and frosts, and reducing sunlight and moisture loss) by a conical tree guard (made of local vegetal material). Some tubes were broken at time of planting, others left intact. Observations were undertaken for 20 months after planting. A small randomized replicated experiment (was made to compare ber plantings (height growth) on windward and leeward slopes (3 aspects, 10 replications).
Grass planting: Grass tuft establishment varied from 10 to 80%. Successful establishment was primarily linked to rainfall at planting. Tufts planted during rainfall or within 24 hours after rainfall, and those receiving a second shower soon after planting achieved 80% success. Aftercare was important in that subsequently ‘overgrazed’ tufts had low survival (note: no values given in original paper).
Tree planting: Survival of saplings planted after the 1965 spring rains was no more than 5%, and drought in May and June subsequently killed surviving individuals. Survival was significantly higher when the earthen tube was left intact at planting, and tree guards enhanced survival (no values given in original paper), but Tamarix all died. As trees grew their expanding roots eventually broke the tube. Better height growth of ber was achieved on southeastern (leeward) slopes.