Pakihi

Pakihi or pākihi is a vegetation association unique to the West Coast of the South Island of New Zealand, characterised by flat boggy land with infertile, waterlogged soil on which only rushes, ferns, moss, and mānuka grow.

[1] Both these ideas are encompassed by the use of pakihi in New Zealand English to refer to open country, mainly on the West Coast of the South Island, from which forest was once cleared but which no longer allows tree growth.

[2] One way pakihi can arise is through the formation of an iron pan in the subsoil, which prevents free drainage and "drowns" forest trees, until only ferns, moss, and scrub can survive.

[5] Around the margins of pakihi are found mānuka, mountain toatoa (Phyllocladus alpinus) and silver pine (Manoao colensoi), which grade into rimu (Dacrydium cupressinum) and kahikatea (Dacrycarpus dacrydioides) swamp forest.

For many years, farmers tried to turn pakihi into productive land, experimenting with sowing different pasture grasses, liming, adding large amounts of fertiliser, and even using explosives to break up the iron pan.

[10][11] One side effect of such large scale land conversion is pest outbreaks, as the "blank slate" created allows insects to multiply rapidly, free of natural enemies.