Page 18 of 20
Around the bases of the fast growing Coriaria arborea, small secondary growth plants were starting to appear, mainly hebe, Pseudopanax, manuka, broadleaf, wineberry and Senicio [Senecio].
Once again bags of duff were collected from the regenerating forest floor and packed around the bases of Coriaria arborea plants
The process was repeated each year until 1982 when the long range weather forecast was for drought. The areas already planted were dusted with bone meal at a rate of 100grms/sq.m. during very light rain.
The early plantings were now covered in open secondary growth up to four metres high and were now forming and trapping leaf debris and windblown dust to an uncompressed depth of 75mm.
Good growth was noted until late November when growth slowed and leaves started to he shed.
By January 1983 there had been a 40% leaf fall and conditions were very dry. A standard Moisture Meter reading of 5.2% was the average on ten sites.
Also in 1983 there was a phenomenal flowering period and 3.5 kilos of ripe fruit was harvested from the early Coriaria arborea plantings, which together with further collected seed, was treated and sown in the now much wider cracks in the last upper site.
By the close of February, the soil moisture reading had risen to 7% average and the leaf shed exceeded 50%.
With the onset of the winter rain, growth started again and before the heavy frosts, new growth on the Coriaria arborea had exceeded 400mm, while the other secondary growth plantings produced new leaves and minor growth.
By January 1984, with the drought in its second year on the Heretaunga Plains, the Coriaria species of the first two years was dying out in the shade of secondary growth. In the open tephra area, the soil moisture averaged 5% but where growth exceeded 2m high, the soil moisture ranged from 20% at 2m, to 31% at 4m high. 50% of the tender species planted as leaf litter in 1981 had died but the two Coriaria species not shaded by secondary growth had almost doubled in height, diameter of ground coverage and branch density.
In the spring of 1984 there was a sudden flush of growth, followed by a tremendous burst of flowering as the drought continued, although some rain was arriving as over-spray from the western side of the ranges. Some shrubs only two years old flowered only to die back. The flowering in more mature shrubs was even and prolific with seed maturing well.
With the drought continuing, only a small quantity of Coriaria arborea seed was gathered and treated to replant the top site that had less than a 2% strike rate, This area was also dressed with bone meal but strong winds removed most of this.
It was hard to tell if the seed had germinated or not on the open areas. Checks indicated that germination had taken place but the new growth had promptly died. In the deep gullies, was a different story, germination took place and about 10% of the Coriaria arborea reached 100mm long. The continued duff plantings were the worst yet with an almost complete lack of germination.
The winter of 1985 saw the density of the secondary growth improving with humus now thinly covering most of the floor and saprophytic bacteria, crustacea and apterygota becoming active. However with the prospect of yet another drought year, no further planting was undertaken.