2.2 Vegetation within the site.

2.2.1 Pakihi

From a distance pakihi appears to be a uniform vegetation of little natural diversity (Figure 1). In composition, however, it is surprisingly diverse with an intriguing range of unusual species. In terms of this project the pakihi, which occupies the crest of the slope west of Glen Gyle Creek, will be influenced by access into the Richmond Flat area. Pakihi replaces forest after repeated burning and colonization by fire-tolerant or dependent, low fertility-demanding, seral (high light-demanding, relatively short-lived) species. The pakihi in this area is low shrubland, 1 to 3m tall, composed of small areas of gorse and needlebush (Hakea sericea), and large areas of manuka, sometimes with scattered emergent kanuka. Scattered throughout are narrow upright shrubs of Epacris pauciflora. In wetter places the manuka gives way to large sedges (species of Gahnia, Scirpus, Juncus and Baumea and others). On the ground is a range of Lycopodium species, spreading patches of fern allies, L. laterale, L. scariosum and L. fastigiatum. Patches of the primitive ferns Gleichenia circinata and Sticherus cunninghammii (umbrella fern) occur in open areas, as do tufts of the very distinctive fern, Schizaea fistulosa (Figure 2). Sundew (Drosera spathulata), Haloragis incana and H. depressa cover bare ground surface in places, with several species of native grasses, scattered sun orchids and ‘tussocks’ of blueberry, Dianella nigra.

While an unusual collection of species well adapted to harsh conditions, this vegetation is widespread in North-west Nelson, does not appear to include any rare species and is capable of regenerating on disturbed ground. There is unlikely to be lasting negative impacts of roading through this vegetation. At the present time there is widespread pig-rooting taking place. In older patches of manuka-dominated vegetation there is an abundance of forest species regenerating within it, including kamahi and rimu.

2.2.2 Secondary broad-leaved vegetation

i. On the western slope leading down to Glen Gyle Creek, the incidence of broad-leaved forest species within the manuka-kanuka pakihi increases, especially kamahi, rimu, tree daisy (Olearia rani), hard beech, and toru (Myrsine salicina). In the moister gullies the volume of vegetation increases and new species enter the composition, especially tree ferns (Dicksonia squarrosa, Cyathea smithii, C. dealbata- silver fern), Coprosma tenuicaulis (swamp coprosma), hutu, pigeonwood and mahoe.

In the valley floor, where uneven ground indicates former gold mining, a secondary forest of silver and hard beech and kamahi has developed, with some young kahikatea in the wettest areas. A few lacebark (possibly a local NW Nelson variety) occur.

ii. True right flank of Glen Gyle. Apart from the heads of upper gullies, where remnant black beech and rimu occurs, the entire west-facing slope along Glen Gyle Creek is a uniform growth of secondary bush emerging through gorse and hakea (Figures 3, 4, 5). The latter are so-called ‘old-man’ specimens, with distinct trunks 10-20cm diameter often collapsing through fungal decay and bearing a cover of moss and ferns (Figure 6). However, they are still forming a scattered canopy towards the upper slopes. Mamaku tree ferns are scattered throughout and sometimes forming pure stands. The broadleaved canopy surrounding them is composed of mahoe, marble-leaf, hutu, Coprosma grandifolia and occasional pate with dense growths of climbing rata (Metrosideros perforata, M. diffusa, M. fulgens) especially on the Dicksonia tree ferns. The large population of mature hutu (Ascarina lucida, one of New Zealand’s more primitive trees), is a feature. There is widespread pig rooting on this slope, and several slips indicate inherent instability.

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