Mosses of Ship Cove, Marlborough Sounds, New Zealand
Total Page:16
File Type:pdf, Size:1020Kb
MOSSES OF SHIP COVE, MARLBOROUGH SOUNDS, NEW ZEALAND. by J.E. Beever1 and P J. Brownsey2 'c/- Landcare Research, Mt Albert Research Centre, Private Bag 92170, Auckland 'Museum of New Zealand Te Papa Tongarewa, P.O. Box 467, Wellington SUMMARY A total of 125 species of mosses from 36 families is recorded from the vicinity of Ship Cove, at the seaward end of Queen Charlotte Sound, Marlborough Sounds, New Zealand (latitude 41°06'S, longitude 174°14'E). Six principal vegetation types were investigated, within an altitudinal range extending from sea-level to 724 m. Particularly rich associations of mosses were found in forest streams, and along the coastal fringe. On Motuara Island, forest regeneration is being accompanied by establishment of a high number of associated forest mosses, probably from forest refugia on the island, and reinvasion from the mainland. INTRODUCTION The area around the historic anchoring point of Captain James Cook in Ship Cove, Queen Charlotte Sound, during his three visits to New Zealand in 1770, 1773 and 1777, is of considerable botanical interest. It is today reserved in a number of Scenic and Historic Reserves (Fig. 1). On the mainland Ship Cove Historic Reserve, Resolution Bay Scenic Reserve and Tawa Bay Scenic Reserve together comprise almost 2000 ha of protected land, with a small area of private land along the foreshore. Motuara Island, the site of Cook's raising the British flag to claim Queen Charlotte Sound and its surrounding lands for King George III, lies 2 km offshore in the centre of the Sound, and is also protected as a Scenic and Historic Reserve. Geologically the area consists of Marlborough Schist, in various states of weathering. Study of the botany of the region by Europeans began with Cook's first visit in January 1770. Then, as in subsequent surveys, bryophytes received only secondary attention. Joseph Banks, on 25 January 1770, while the Endeavour was anchored in Ship Cove, recorded in his journal 'Dr Solander and myself (who have now nearly exhausted all the Plants in our neighbourhood) went today to search for Mosses and small things, in which we had great success gathering several very remarkable ones' (Beaglehole 1962). What became of these specimens is not known, and no bryophytes appear for New Zealand in the unpublished 'Catalogue of the plants of Cook's First Voyage' (Beaglehole 1962). 155 lane, VoL 34, 1993 Fig. 1. Map of study area, with insets showing location with respect to Cook Strait in central New Zealand. Dotted lines represent boundaries of reserves. * marks site of Cook Monument in Ship Cove. Since that time few collections of bryophytes appear to have been made in the area. Some specimens of mosses have been located by us in herbaria, e.g. 156 Tane, VoL 34, 1993 collections by J. H. McMahon made in the 1920s and by G. Brownlie in the 1970s. The modern vascular plant vegetation and flora of the area have been documented in detail by Walls (1984), as part of a biological survey of reserves in the Marlborough Land District. Vegetation types in the area were found to be complex, with 9 types of forest and scrub recognised in the Resolution Bay and Ship Cove Reserves alone. Apart from a brief record of the abundance of 'lower plants' ('high' for Resolution Bay Scenic Reserve/ Ship Cove Historic Reserve, 'medium' for Tawa Bay Scenic Reserve, and 'low' for Motuara Island Scenic and Historic Reserve), mosses were not included. The present account is based on collections and observations made during 9 'bryologist-days' in the field with the Offshore Islands Research Group while camped at Resolution Bay between 31 December 1991 and 7 January 1992. Two 'bryologist-days' were spent on Motuara Island, and the remainder on the adjacent mainland in the three reserves listed above, and on private land along the foreshore of Resolution Bay. For the purposes of the present account we recognise 6 broad vegetation types, as follows: 1. Coastal fringe vegetation 2. Pasture and cut grass 3. Kanuka/manuka-dominated regenerating forest 4. Mixed regenerating forest 5. Beech forest 6. Podocarp/broadleaf forest. RESULTS 1. Coastal fringe vegetation A dense coastal scrub occurs around much of the foreshore, with wharariki (Phormium cookianum), karamu (Coprosma lucida), taupata (C. repens), kawakawa (Macropiper excelsum), and rangiora (Brachyglottis repanda) being the commonest vascular plants, often with a dense fringe of the large coastal grass Poa anceps lowest on the shore. Tauhinu (Cassinia leptophylla) occurs in more open sites, with shore lobelia (Lobelia anceps), pearlv/otf£(Sagina procumbens), and New Zealand iceplant (Disphyma australe). This vegetation type was examined for mosses in the eastern part of Resolution Bay, the northern end of Ship Cove, and on the south-west and eastern coasts of Motuara Island. This habitat was found to contain a relatively diverse and luxuriant array of mosses. The most abundant species was Calyptrochaeta apiculata, occurring in 157 dense swards on slightly damp soil at the base of the sea cliff. In some exposed sites it formed patches several square metres in extent, but was also found in dense shade, under overhanging vegetation. Fissidens leptocladus was also common in weak seepages, sometimes forming a 30 cm wide band below Calyptrochaeta apiculata. In drier sites the moss we provisionally name Hymenostomum patulum was common, as was Ditrichum difficile, the latter frequently occurring under overhangs. Other species of interest in this habitat included Ptychomitrium australe, Ischyrodon lepturus and Bartramia papillata. 2. Pasture and cut grass Rough pasture covers the slopes around the foreshore in the central part of Resolution Bay, with Yorkshire fog (Holcus lanatus), sweet vernal (Anthoxanthum odoratum), and browntop (Agrostis capillaris) being common component grasses, together with narrow leaved plantain (Plantago lanceolata) and a species of lotus (Lotus sp.). In less well maintained areas the shrubs barberry (Berberis glaucocarpa), tauhinu and kanuka (Kunzea ericoides) were common, with extensive patches of scented fern (Paesia scaberula). Areas of cut grass have been established around dwellings, and adjacent to the Cook Monument in Ship Cove. In dry open sites, amongst pasture grasses, Thuidium furfurosum and Hypnum cupressiforme were the commonest mosses, with Polytrichum juniperinum and Ceratodon purpureus occasional associates. On vertical clay banks Ditrichum difficile and Fissidens asplenioides were often present, while narrowly incised water-courses running through pasture provided shaded, moist habitat for species such as Pohlia wahlenbergii, and Philonotis pyriformis. In cut grass Stokesiella praelonga was the commonest moss, with concrete structures providing substrate for Tortula muralis, Bryum argenteum and B. dichotomum. 3. Kanuka/manuka-dominated regenerating forest Extensive areas of the lower slopes of the Resolution Bay catchment are covered in a regenerating vegetation dominated by kanuka and manuka (Leptospermum scoparium). Associated tree species include putaputaweta (Carpodetus serratus), mahoe (Melicytus ramiflorus), five-finger (Pseudopanax arboreus), kamahi (Weinmannia racemosa), wineberry (Aristotelia serrata) and rangiora, with the tree-fern, mamaku (Cyathea medullaris) common in gullies. A similar forest type covers much of the upper slopes and main ridge of Motuara Island. In the driest sites, under a light canopy of kanuka and manuka, Thuidium furfurosum, Hypnum cupressiforme, Campylopus clavatus and Ptychomnion aciculare were common on the accumulated duff, with Leptostomum 158 macrocarpum forming extensive clumps on rock outcrops. In moister sites, in the gullies, Hypnodendron arcuatum, Fissidens anisophyllus and Achrophyllum dentatum were common on soil, with Thamnobryum pandum frequently colonising rock, and Racopilum convolutaceum occurring on a variety of substrates. On cut soil banks at the edge of tracks Fissidens asplenioides, Ditrichum difficile and Pogonatum subulatum formed extensive patches. Epiphytes, which were mainly members of the Orthotrichaceae, were occasional in this vegetation type, occuring most often on the bases of tree trunks and on exposed roots. 4. Mixed regenerating forest A secondary forest, lacking kanuka and manuka, but with a diversity of tree species including kohekohe (Dysoxylum spectabile), tree fuchsia (Fuchsia excorticata), mahoe, wineberry, putaputaweta, heketara (Olearia rani) and kanono (Coprosma grandifolia) is found in the Ship Cove and Resolution Bay catchments, and on much of the lower slopes of Motuara. The tree fern, mamaku, is very frequent in gullies, with the silver fern (Cyathea dealbata) more common in drier sites. In this forest type streams were found to be particularly rich habitats for mosses, with luxuriant masses of bryophytes covering much of the available substrates both in, and adjacent to, the water. The tops of boulders were frequently covered with stands of the umbrella moss Hypopterygium commutatum, and their sides fringed with luxurious clumps of both Cyathophorum bulbosum and Calyptrochaeta cristata. Thamnobryum pandum and Eurhynchium austrinum were both common on rock in the splash zone of small waterfalls, and submerged in fast-flowing water, while Fissidens rigidulus, often the most common moss in such habitats elsewhere, was only occasional. A luxuriant, bright green form of Thuidium furfurosum, with abundant capsules, was often observed in the zone of frequent flooding. Out of the stream, on the sloping gully sides, Fissidens