Grasslands of the World.pdf - Disasters and Conflicts - UNEP

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Grasslands of the world
Reseeding has been tried, with limited success, using thirty-two different
species of grasses in Kenya (Bogdan and Pratt, 1967), although disturbance
with subsequent colonization and regrowth was found to be successful for
revegetation in the Serengeti Plains of Tanzania (Belsky, 1986). Options to
improve success in Kenya were identified as selection of appropriate species
for the ecosystem , good quality seeds, integration of reseeding with overall
land management policy, adequate seedbed preparation, reasonable rain and
a complete rest from grazing during the establishment period (Bogdan and
Pratt, 1967). Chloris roxburghiana was difficult to establish in the south Kenya
rangelands using seeds collected from natural stands (Mnene, Wandera and
Lebbie, 2000). While there is the opportunity to introduce more productive
exotic species into the system, these may often not be as well suited to the
environment as the indigenous species and may not establish well. The study
by Mnene indicated that ecotypes of the same species from different areas also
showed poor establishment compared with seeds collected from populations
in the same area.
Seed supply to support reseeding is a major constraint in eastern Africa
and most species have to be collected from the wild (Bogdan and Pratt, 1967),
a situation that has changed little over the past 30 years. Most succession in
pastoral areas is through natural means, such as wind dispersal, although some
projects are collecting seeds from natural stands for revegetation purposes.
A limited number of cultivars of Rhodes grass , setaria, coloured guinea grass
(Panicum coloratum) and signal grass (Urochloa decumbens) are available in
Kenya from the Kenya Seed Company. These are useful for pasture establishment
but have limited use for reseeding rangelands, except for revegetation of
the Hyparrhenia tall-grass region as described by Herlocker (1999) and other
areas where these grasses are an important part of the natural ecosystem . These
species can also be used for range improvement due to their high palatability
and nutritive value, but establishment is often poor due to low rainfall and
competition , as well as open grazing during the establishment phase (Bogdan
and Pratt, 1967).
PRIORITIES FOR RESEARCH AND DEVELOPMENT PROGRAMMES IN
PASTORAL LANDS
Some history
In the late 1970s, the World Bank withdrew 98 percent of its funding to
pastoral research and development because there had been little progress
in improving the intensity of production in livestock-dominated systems
(de Haan, 1999). The pressure to intensify existed despite the fact that crop
cultivation of ten failed in these systems and often was unsustainable over
the long term (Niamir-Fuller, 1999). Intensification of production has had
such success in higher potential land that policy-makers assumed it was
appropriate for pastoral lands, particularly because most policy-makers have