Waihi North Project: Assessment of Terrestrial Ecological Values & Effects 62138 WNP AEE 54 The canopy is often discontinuous, dominated by rewarewa and tall pole Cyathea cunninghamii, however pōhutukawa are also present throughout, including some large, mature trees (none kauri or any other threatened or ‘At Risk’ species). The pōhutukawa were checked for signs of myrtle rust, and none were found at the time of assessment. The subcanopy includes silver fern and mamaku . The understory comprises rangiora , prickly mingimingi , several Coprosma species (C. robusta, C. areolata, C. rhamnoides), mapou and an abundance of towai. In steep rocky areas, epiphytic-associated ferns (Asplenium flaccidum, A. polyodon, Microsorum scandens, M. pustulatum) and the coastally-associated Astelia banksii are dominant. Barberry, Japanese honeysuckle, and gorse are present, particularly around the edges. As with SNA 166, the vegetation within the western block would have historically been WF12 kauri, podocarp, broadleaved forest (Singers & Rogers, 2014, (there are a few isolated, relict kauri trees beyond this fragment in the surrounding farmland landscape)) and is lacking many characteristic flora of this forest type (tōtara, rimu, kauri). Aerial imagery from 1982 (Figure 7) indicates that the vegetation within the western block is at least as old as the most mature parts of SNA 166. Regenerating scrub on the western and eastern blocks (Figure 22) to the southeast of SNA 166 support some boulder deposits which enhance habitat complexity and potential habitat values for ground dwelling lizards. The north-facing edges of these blocks may provide greater basking opportunities where there are higher light levels and boulder deposits. No surveys were undertaken to sample for lizards. 5.3.2.1.1 Ecological value and significance of vegetation within Western Fragment Representativeness The vegetation within the Western Fragment has low species richness and is generally a relatively young, regenerating area of native and exotic vegetation that supports some older trees, around which the younger vegetation is regenerating (Figure 28). The ground cover is grazed where it is not too steep for cattle, and canopy varies between a few sprawling pōhutukawa, some rewarewa and tree ferns. As with SNA 166, this fragment has been degraded by grazing and edge effects, and has low species richness. The representativeness of the fragment is assessed as low. Rarity and distinctiveness No rare species were recorded and (as with other areas) the disease-elevated species (pōhutukawa, kānuka, mānuka) . Therefore, this assessment concludes a low score for rarity and distinctiveness. Diversity and pattern As noted above, there is a low species richness and a low diversity in general of species and structures. There are some small gradients related to slope and hydrology but little evidence of vegetation assemblage responses to those gradients and therefore minimal evidence of patterns in the fragment. By and large the level of modification, ecological simplicity, age and high weed incursion result in the diversity and pattern of the fragment to be low. Ecological Context The feature is small (1 ha) and rather elongated (220 m long and 50 m wide and is largely all edge habitat). While it is close to the southern edge of the southern fragment of SNA 166 it does not
RkJQdWJsaXNoZXIy MjE2NDg3