Natural grasslands in the basaltic region of Uruguay are threatened by
an increase in stocking rates and changes in land use. To assess the
effect of grazing intensification, plant functional types are proposed
as simple tools to aid the monitoring and management of vegetation. In
the present study we evaluated the effect of stocking rate increase at
community level taking into account plant traits of 23 dominant
perennial grass species. In order to identify plant functional types,
we determined the grazing response in an experiment with two wethers
stocking rates (0.78 and 1.56 livestock units ha-1) quantifying species
cover and traits values. Leaf dry matter content (LDMC) and specific
leaf area (SLA) were the traits that best described the perennial
grasses response to the stocking rate increase and therefore are
suggested to be used as functional markers. Three functional types were
identified. Low stocking rates were related to functional type A (tall,
warm season species with low SLA and high LDMC and functional type B
(tall, cool-season species, with intermediate levels of leaf traits).
On the other hand, high stocking rate encouraged functional type C
(prostrate, warm season species, with high SLA and low LDMC). The
classification of a highly diverse community into three functional
types and the selection of traits as functional markers candidates is
an innovative approach to develop simple and general methods to
diagnosis the state of basaltic grasslands in Uruguay and to advise on
its management