Publication Date
1997
Description
Long term Agroforestry trials were established in the North and South Islands of New Zealand between 1971-76. They compared a range of final tree stockings of Pinus radiata planted into pasture with open pasture control plots and were measured for tree growth parameters and agricultural production. This paper presents the results of pasture species changes over the period of tree age 10-22 years. Pasture species composition under Pinus radiata changed with time, dependent primarily on the rate of canopy closure. Changes occurred relatively rapidly in high tree stocked areas of 400 stems per hectare (sph) in the North Island trials where ryegrass (Lolium perenne L) and white clover (Trifolium repens L) were replaced with annual and native grass until canopy closure resulted in loss of all pasture by tree age 13 years. In lower tree stocked areas these changes occurred more slowly so that by tree age 19 years, pasture species such as Yorkshire Fog (Holcus lanatus) and annual grasses (Poa Species) still contributed to the ground cover. In the South Island trials, pasture persisted longer into the tree rotation. Open pasture (0 sph) retained similar pasture species to that at the trial commencement in all locations. A point analysis technique at one North Island site gave a good measure of ground surface cover over time.
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
Changes in Understorey Pasture Composition in Agroforestry Regimes in New Zealand
Long term Agroforestry trials were established in the North and South Islands of New Zealand between 1971-76. They compared a range of final tree stockings of Pinus radiata planted into pasture with open pasture control plots and were measured for tree growth parameters and agricultural production. This paper presents the results of pasture species changes over the period of tree age 10-22 years. Pasture species composition under Pinus radiata changed with time, dependent primarily on the rate of canopy closure. Changes occurred relatively rapidly in high tree stocked areas of 400 stems per hectare (sph) in the North Island trials where ryegrass (Lolium perenne L) and white clover (Trifolium repens L) were replaced with annual and native grass until canopy closure resulted in loss of all pasture by tree age 13 years. In lower tree stocked areas these changes occurred more slowly so that by tree age 19 years, pasture species such as Yorkshire Fog (Holcus lanatus) and annual grasses (Poa Species) still contributed to the ground cover. In the South Island trials, pasture persisted longer into the tree rotation. Open pasture (0 sph) retained similar pasture species to that at the trial commencement in all locations. A point analysis technique at one North Island site gave a good measure of ground surface cover over time.
