TANE 24, 1978 ESTABLISHMENT AND MONITORING OF PERMANENT LICHEN QUADRATS AT KAWERUA, NORTHLAND, NEW ZEALAND by Roger V. Grace* and Glenys C. Haywardf *274a Birkdale Road, Birkenhead, Auckland 10 135 Trafalgar Street, Waterloo, Wellington SUMMARY Six permanent quadrats were established in October, 1976 for monitoring lichens in the maritime zone at Kawerua. Photographic sampling of the quadrats in January, 1978 indicated that some foliose species had grown up to 5 millimetres, whereas growth of crustose species was about 1 millimetre. INTRODUCTION The Auckland University Field Club hut at Kawerua is located on the rugged west coast of the Northland peninsula. The hut is visited several times a year by Field Club members, access being by permit only through the Waipoua State Forest. The presence of the hut provides ideal opportunities for long-term studies of natural phenomena. The lichen flora of the Kawerua area is described by Hayward and Hayward (1974), including the maritime lichens in the zone above the rocky shoreline. This zone contains mainly crustose and foliose species, which are suitable subjects for a long-term photographic study of growth and other changes. The locality chosen for the study is a prominent point about 1 kilometre south of the Kawerua hut, where detailed studies of intertidal and maritime lichens were carried out by Hayward and Hayward (1974). METHODS The general locations of the six quadrats are indicated in Fig. 1, in which the map and vegetation details are adapted from Hayward and Hayward (1974). Each quadrat is rectangular in shape, with the long axis measuring 0.5 metre. Each corner of each quadrat was permanently, but inconspicuously, marked in the following way. A hole was drilled in the basalt rock with a hand drill and 5.6mm (No. 10) masonry bit. A short length of firm plastic tube was hammered into the hole and a tight-fitting plug of grey PVC welding rod forced down the bore of the tube. The resulting marker was trimmed off so that between 5 and 10 millimetres remained projecting from the rock surface. Each quadrat was prepared for photographing by placing a loop of white hat elastic over the four corner markers to outline the quadrat. A label with the 173
0 J 0 of metres 3 Lichen quadrat Meuhlenbeckia v Scirpus Flax Cassinia Sa I i corn i a Fig. 1. Location of lichen quadrats. Map and vegetation details after Hayward and Hayward (1974). 174
quadrat number and date was held in the top left corner of the quadrat with a small clip, and a metric measuring tape held along the top edge of the quadrat. Quadrats were photographed in black and white using a Pentax SLR camera. Diffuse, even natural lighting was achieved by shading the area with an umbrella. A set of colour slides was taken for personal reference. QUADRAT DETAILS Figures 2 to 13 show the detailed locations of all quadrats, and close-ups of each quadrat when first established on 25 October, 1976. Quadrat details and lichens present are indicated in Table 1. Aspect and angle of slope of the rock surface at each quadrat were measured with a Silva compass. The lichen species lists for each quadrat are based on preliminary field identifications only, and await more detailed analysis. A number of the species, particularly crustose forms, cannot be identified because of the difficulty of Table 1. Quadrat details and major lichen species. Quadrat No. Aspect Angle of slope Major lichens present (in approximate descending order of abundance) 1 240 15 Xanthoria parietina var. parietina Lecidea sp. Melanoparmelia sp. "Xanthoparmelia isidiigera" 2 280 105 Buellia sp. Caloplaca sp. Ocellularia sp. Buellia punctata 3 5 55 Xanthoria parietina var. parietina "Xanthoparmelia isidiigera" Buellia sp. Ocellularia sp. 4 185 20 Buellia sp. Caloplaca sp. "Xanthoparmelia isidiigera" 5 215 55 Buellia sp. Buellia stellulata 6 125 90 Buellia sp. Buellia punctata Physcia sp. 175
176
178
Fig. 8. Location of quadrat 4. View from the south-west 2SI'10 jit r 1, Fig. 9rQuadrat 4 detail, 25 October, 1976. 179
180
182
field identification and the lack of knowledge of the New Zealand lichen flora. Present taxonomic problems, however, are not considered a hindrance to the establishment of the monitoring programme, as these will probably be resolved in time. CHANGES The quadrats were re-photographed on 1 January, 1978. Because changes until then were relatively minor, only two of these photographs are presented here, for quadrat 1 (Fig. 14) and quadrat 6 (Fig. 15). One of the more obvious changes was an apparent seasonal change in colour of some of the lichens (e.g. Xanthoria parietina var. parietina), and the background rock. The background "rock" was darker on 25 October, 1976 than on 1 January, 1978, possibly because of seasonal changes in micro-algae inhabiting the rock surface. These changes created minor difficulties in subsequent analysis of photographs by presenting different contrast characteristics between the initial and subsequent samplings (compare Figs 3 and 14). Growth of lichens from 25 October, 1976 to 1 January, 1978 was apparent on all quadrats. Foliose species such as Xanthoria parietina var. parietina, "Xanthoparmelia isidiigera" and Melanoparmelia sp. had expanded about 5mm at the edges of thalli (see quadrat 1, Figs 3 and 14). Crustose species, however, such as Buellia sp., had grown only about 1mm, and their growth was in fact barely detectable in the photographs (see quadrat 6, Figs 13 and 15). Other minor changes included the degeneration of central parts of some of the larger foliose thalli on quadrats 3 and 4. Minor mechanical disruption of thalli occurred, probably from people walking over the area, on quadrats 1 and 4, which are on relatively level rock surfaces. FUTURE MONITORING It is hoped to follow and report further changes in the lichen flora of the quadrats at intervals of several years. Clearly the longer the monitoring continues, the more useful it will become. The authors invite present and future Field Clubbers to continue monitoring these quadrats if they wish. REFERENCE Hayward, B.W. and Hayward, G.C. 1974: Lichen flora of the Kawerua area. Tane 20: 124-139. 183