Perennial grasses traits as functional markers of grazing intensity in basaltic grasslands of Uruguay

Abstract

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.

Nutrient Characteristics in Relation to Plant Size of a Perennial Grass Under Grazing Exclusion in Degraded Grassland

“…The sensitivity of stems was higher than that of leaves with the increase of grazing exclusion time, indicating that L. chinensis can exhibit rapid pant growth by promoting stem elongation. A previous study on leaf traits indicated that the strategies for stability and plant protection under grazing disturbance provides some indirect evidence for our findings ( Jaurena et al, 2013 ).…”

Long-term ecological research in southern Brazil grasslands: Effects of grazing exclusion and deferred grazing on plant and arthropod communities

“…This preferential grazing promotes heterogeneity by creating a mosaic of patches under different grazing pressures in the landscape, with the selection of plants that share traits compatible with each local disturbance [7,8]. Conversely, grazing exclusion, or very low grazing intensities, may benefit species with certain traits, such as the tussock habit of many C4 grasses (e.g., [14,15]), and ligneous species such as shrubs [16]. In the absence of disturbance, such species may dominate, homogenize, and ultimately change the structure of large patches via competitive exclusion [17,18], and these effects may be detected in different spatial components of diversity [12,19].…”

Temporary grazing exclusion promotes rapid recovery of species richness and productivity in a long‐term overgrazed Campos grassland

“…Major advances have occurred in the recent years in understanding the plant–animal relationships at Campos biome (Carvalho et al ; Nabinger et al ; Cruz et al ; Da Trindade et al , ; Jaurena et al ). These works showed the benefits of moderate grazing intensity on plant diversity, functional types composition, pasture productivity, and animal performance.…”