Publication Date
1997
Description
A model is presented that analyses the potential effect of vertebrate grazing on the partitioning of grasses. Its conclusions are: 1) When grazing is sufficiently frequent and severe, grasses can increase their net increase in biomass by partitioning growth to reserves. 2) Partitioning growth to reserves greatly reduces leaf growth between defoliations. After repeated clipping, dryland browntop (Agrostis castellana) and red fescue (Festuca rubra) allocated a smaller proportion of growth between defoliations to leaves than ryegrass (Lolium perenne) or rough meadow-grass (Poa trivialis). Browntop and fescue achieved less leaf growth than ryegrass and meadowgrass between defoliations, but their total biomass increased faster through a series of repeated weekly clippings.
Citation
Birch, C P.D. and Thornton, B, "Theoretical and Observed Relationships Between Defoliation and Partitioning in Grasses" (2024). IGC Proceedings (1993-2023). 22.
https://uknowledge.uky.edu/igc/1997/session7/22
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
Theoretical and Observed Relationships Between Defoliation and Partitioning in Grasses
A model is presented that analyses the potential effect of vertebrate grazing on the partitioning of grasses. Its conclusions are: 1) When grazing is sufficiently frequent and severe, grasses can increase their net increase in biomass by partitioning growth to reserves. 2) Partitioning growth to reserves greatly reduces leaf growth between defoliations. After repeated clipping, dryland browntop (Agrostis castellana) and red fescue (Festuca rubra) allocated a smaller proportion of growth between defoliations to leaves than ryegrass (Lolium perenne) or rough meadow-grass (Poa trivialis). Browntop and fescue achieved less leaf growth than ryegrass and meadowgrass between defoliations, but their total biomass increased faster through a series of repeated weekly clippings.
