Influence of environmental factors on the abundance of naturalised annual clovers in the South Island hill and high country
Abstract
The abundance of four naturalised annual clovers
(striated, cluster, suckling, haresfoot) and two
sown clovers (subterranean and white clover) was
investigated in relation to topographical, soil fertility
and management factors on two contrasting hill/high
country stations in the South Island: Glenfalloch in
inland Canterbury (1 665 mm annual rainfall), and Mt
Grand in Central Otago (703 mm annual rainfall). Site
surveys were conducted in three hill blocks per farm,
with measurements of grassland species cover, slope,
aspect, grazing intensity, soil fertility, soil depth, and
altitude made within quadrats along three transects at
upper, middle and lower hill slope positions. The only
naturalised clover present at Glenfalloch was suckling,
whereas all were present at Mt Grand. The % cover
of naturalised annual clovers was greater (30.1) than
that of white clover (3.8) or subterranean clover (0.1)
at Mt Grand. The % cover of white clover decreased
with increasing altitude. The % cover of striated and
cluster clover was greatest on sunny aspects, while
white clover % cover was greatest on shady aspects.
White clover cover increased and striated clover cover
decreased with increasing available soil phosphorus.
Naturalised annual clovers exhibit regeneration and
persistence strategies that allow them to regenerate and
grow in dry hill/high country pastures.
