Sustainability of high-country pastures under contrasting development inputs. 9. Vegetation dynamics

Abstract

Changes in pasture composition over 24 years are reported for two grazed multiple-species mixture trials on a high-country soil. Quantified response equations (34) between different plant species ranking, vegetation types, time, fertiliser and grazing input treatments for 19 years are reported depending on whether estimation is of “species from environment” (species response from treatment variables) or “environment from species” (treatment variables from species composition). Species abundance and vegetation type were primarily determined by S and P fertiliser levels, duration of development, and only secondarily by relative stocking rate or grazing method. Species dominance and vegetation continued to change over time. Lupinus polyphyllus was dominant over most of the period at low fertiliser input levels, while Trifolium ambiguum increased steadily to dominate in the higher fertiliser input levels during the second decade, with both as sustainable pasture species options. © 2007 Taylor & Francis Group, LLC.