TheImprovement ofTropical and Subtropical Rangelands

230 IMPROVEMENT 01' TROPIOAL AND SUBTROPIOAL RANGELANDS
Middle Atlu and blocking all winter movement of man and beut
across the mountains, the absence of snow in the lower elevations is
an essential prerequisite for the successful winter pasture of the Beni
Mguild in the Azaghar.
Vegetation shows a vertical zonation similar to the distribution
of rain and snow.13 Cedar (Cedrus atlantica) is found on the higher
slopes of the more humid northern and central portions ofthe Middle
Atlu. The distribution of the cedar begins at about 1,300 m and
extends upwards to the snow line at about 2,200 m. However, above
2,200 m regeneration is difficult; hence, an herbacious vegetation
nourished by snow melt emerges in the spring. Downslope from the
cedars is the zone of evergreen oaks and occasionally of thu,tJ (Co.1­
litm tJrticulattJ) , which is frequently degraded by cutting, browsing,
and burning into a mtJquu assemblage. Numerous grll8l!lell and agricultural
stubble, important for foraging, are found below 2,000 m.
On the eutem slopes of the Middle Atlu, the entire character of the
vegetation changes, for the rainshadow effect of the mountains favors
the development of a steppe complex, where e,parto (Stipe tenacis·
lima)-a tough tu880ck grass, inedible during most of the year-is
most common.
The natural regime sketched above is one of distinct seasonal
and altitudinal variation in the availability of pasture and water. In
summer, agriculture engages the attention of tribesmen in lowland
and plateau areas, and the herds are kept in the upland areas over
2,200 m to take advantage of putures nourished by melting snow
or the esparto of the Moulouya Valley. In winter, herds are moved
to the lowland plateaus of the Azaghar, where milder temperatures
and adequate rainfall permit abundant grazing on unoccupied land
or harvested fields. Actually, as indicated below, the system is still
more complex, for the Beni Mguild are engaged in cereal farming in
the Moulouya Valley at the same time that they are shifting their
herds from zone to zone.
MIGRATORY CYCLE
The Beni Mguild are divided into two major groups, a northern
and a southern, and it is the migratory pattern of the southern group
that is considered here (figure 2-1). The southern Beni Mguild are, in
turn, divided into four separate subtribes, each with its own slightly
different adjustments, migratory routes, and areu of cultivation and
pasturage. The northernmost of these subtribes, the Alt Lias, begin