Response of plant functional types to grazing intensity in grassland

Abstract

The objective of this work was to identify responses of grassland vegetation, described by speciesand plant functional types, to different grazing intensities. In order to describe the vegetation, 0.25 m² quadratswere used in the spring and summer. Vegetation description involved identification and cover-abundanceestimation of the species in each quadrat. Each species was described by 21 macro-morphological qualitativeand quantitative attributes. Data analysis aimed at identifying functional types as a subset of attributes thatmaximized the congruence ρ(D; Δ), between the variation of the vegetation (matrix D) and of the forage available(matrix Δ). Ordination revealed plant functional types that, concerning cover-abundance, responded more clearlyto this factor. Multivariate analysis of variance with randomization testing was used to compare the vegetationcomposition, as described by plant functional types, among the forage available levels, and significant differences(P = 0.002) were observed. The differences were not significant when vegetation was described by the speciescomposition. The use of plant functional types is more effective to detect the result of grazing intensity than theuse of species composition.