Building a riverside forest

Forest and Bird, Issue 292, 1 May 1999, Page 40

Building a riverside forest

Private planting project inspires community action on riverbanks writes MARGARET RICHARDSON

aap van Dorsser always J dreamed of creating a forest. Several thousand trees, hours of back-breaking labour, and many years later, this dream has become a reality. Forest and Bird members Jaap and his wife Sue live on a 3.7-hectare lifestyle block north of Rotorua, with the crystal clear Awahou stream on their boundary. It would normally be considered a great asset to have a beautiful stream running past your property, but until recently Jaap and Sue could not even see it for blackberry. Back in the 1980s, the local catchment commision devised a scheme requiring all major streams feeding Lake Rotorua to be fenced off. This represented an important step toward improving the water quality of the lake. By excluding all grazing animals from riparian strips, streams previously soiled by pasture run-off cleared remarkably. The flip-side was that previously grazed streambanks soon became infested with blackberry. Unless youre a goat, blackberry is very nasty stuff, and little can grow up through a well-established patch. Since every root system throws up a new shoot every year, layer upon layer of blackberry forms a dense barrier to light, and greatly delays natural succession to forest trees. While most landowners despair at these impossible thickets and turn a blind eye, Jaap, a retired forest nurseryman, saw the perfect site for

his forest. Armed with slashers, spades, the odd bonfire and several gallons of spray, the enterprising couple laid siege on the virulent weed. Most people could probably imagine more relaxed ways of spending

their retirement, but as Jaap says, ‘I don’t like golf and ’m very fond of trees.’ Once the blackberry was cleared and the root crowns dug out, they began planting native species. With a long background in forest-tree propagation, Jaap has broad experience in the field as well as ‘valuable contacts who are sympathetic to the cause.’ Obtaining hundreds of leftover shrubs from nurseries every year, the van Dorssers aimed for a high, initial planting density. As Jaap says, ‘If you want to make a forest, you just have to close the canopy as quickly as possible’. While this is a long-term project — in the extreme — the short-term requirements are clear and demanding. The van Dorssers are more concerned with coverage than artistic placement, and species are planted according to availability. For this reason, the for-

est is a bit of a hotch-potch to start with, but they know a more even distribution will result over time. The older areas of planting, dating back to 1965, are already taking on the variety and balance of a natural forest environment. The van Dorssers have planted a number of totara, beech, rimu and other tree species that grow in the area, but natural seeding has also taken place. They say there is nothing more satisfying than seeing wild kahikatea emerge from the undergrowth. By establishing a ground cover of ‘pioneer species’ such as coprosma, pittosporum, flax and other fast-growing varieties, blackberry is eventually prevented from re-invading the riparian area. The initial canopy also provides cover for most frost-tender species to establish. While strict forward planning is not necessary in creating

their forest, the van Dorssers have found it useful to construct clearly defined pathways from the outset, to provide easy access and future enjoyment. After the initial clearing, Jaap and Sue must spend the next three or four years keeping weeds out, so that juvenile plants can get properly underway. ‘Once decent shade is established, a natural progression takes over and canopy trees emerge, which would previously have been choked’ While they do the initial groundwork, nature does the rest. All they have to do is wait, and Jaap, with his affinity for ‘long horizons’, has the perfect temperament for a project of this kind. Every year, the retired couple work their way further along the stream, so the forest can be seen at several stages of development. "The end would be in sight if

we didn’t have that constant, niggling desire to go round the next bend. So impressive are the results of this project that other landowners and local authorities have followed their lead. Jaap has been appointed project leader of an environmental sub-committee formed by the Ngongotaha and Districts Community Association, to continue this work on a larger scale. What started as a personal vision by this hard-working Dutchman with a love of New Zealand flora has grown into a vigorous community project. ‘All we wanted to do was make our stream beautiful, the van Dorssers say. Nature is rewarding their efforts by ensuring this is the case. As an added bonus, efforts by the community association will now enable other streams in the area to support the same beauty over time.