soil-conservation-people-religion-and-land.pdf - South West NRM

will be referred to later. It is deemed useful here to
reiterate the original basic concepts from which modern
monitoring evolved.
The first proposed range condition assessment was that of
Smith (1899) who suggested that "the occurrence of any one
species as a dominant or most conspicuous grass is, to some
extent, an index of the state of the land and of what stage in
overstocking and deterioration has been reached". (It is
interesting to note at after 50 years of range assessment,
South African scientists have recently proposed a system using
species composition as the only criterion of condition
(Tainton, 1986) ) .
Range condition may be described as the general state of
health of natural grazing land and was originally defined as
follows: "The state of health or productivity of both soil
and forage of a given range, in terms of what it could or
should be under normal climate and best practicable
management" (Sampson, 1952). Because conditions may be
changing, a report ~f~condition is always with reference to a
certain time and as Dyksterhuis (1949) has pointed out, data
on condition are gathered Ifto show current condition in
relation to potential condition, thus enabling a range manager
to recognize an attainable goal1v. (Note that Moore (1969)
maintained that "the principle objective of management must be
to maintain or re-establish conditions suitable for the
regeneration and survival of useful species ...fr.)
One of the simplest definitions of condition is that of
Ellison (1951) which states that "condition is the character
of the vegetal cover and the soil, under man's use, in
relation to what it ought to be".
The term "range trendv1 refers to the direction of change in
condition of natural grazing land. In its original context,
lgtrendvl indicated whether "the state of health, and thus
productivity of rangeland, was moving toward or away from the
climax condition. In its simplest terms @@trendwt is change in
condition. Both the direction and the rate of change in range
condition are embraced by the concept of "trend" and are
influenced by a complex of environmental and management
factors,
The use of the "key speciesg1 concept was first proposed by
Standing (Anon, 1938) as a basis on which correct utilization
of grazing land could be judged. The key species are those
species on which the correct level of defoliation for the
vegetation as a whole is judged. Key species should be
palatable, reasonably resistant to grazing and competition,
reasonably abundant and nutritious and should produce a
reasonable volume of feed. Usually 2-4 key species are chosen
for use as indicators of proper utilization. In some cases
one dominant may suffice and when this is judged to have been
properly used (vlmaximum allowable defoliation without damageRf)
it is assumed that the range as a whole should not be grazed
further .