G. A. M. Scott

Forest Succession on landslides above Lake Thomson, Fiordland

Summary Forest succession following Ianilsliiles is described from an altitude of about 1,000 ft on a steep northerly slope above Lake Thomson, west of Lake Te Anau, in Fiordland. Two distinct serai patterns are described from six adjacent stands, ranging in age from 15 years to mature forest. On the denuded slip-faces the relatively drought tolerant Leptospermum scoparium is the principal seral species. On the detritus of the debris-fans, almost pure stands of Aristotelia serrata, followed by Fuchsia excorticata and possibly by Hoberia glabrata, intervene before the return of the climax forest dominated by Nothofagus menziesii. For each of the six stands, the structure and composition of the vegetation and a brief description of the soil is presented.

Vegetation studies on Secretary Island, Fiordland

Summary The quantitative composition of epiphytic and ground vegetation (excluding vascular plants) is recorded from three stands of lowland forest and one stand of subalpine forest near the NW corner of Secretary Island. Ground vegetation was sampled by local frequency measurements in blocks of 25 one dm2 quadrats; the abundance of epiphytic species was estimated visually and then converted to approximate cover values using empirical conversion constants. Lists are also given of species collected from several sources above tree line on Secretary Island and from coastal forest on the adjacent mainland, together with a list of all bryophytes known to occur on the island. The feasibility of pooling data from different stands of forest is discussed; there is no evidence in the Secretary Island data to warrant pooling except between different stems of the same phorophyte species within a stand. Several epiphytes of tree-fern trunks seem to have very strong substrate preferences; otherwise the data are not ade...

Altitudinal variation in forest composition near Lake Hankinson, Fiordland

Abstract A description is given of forest composition and structure on a spur near Lake Hankinson, Fiordland, at approximately 500 ft intervals from the valley floor at 700 ft to near tree line at 3,000 ft. Density values are given for tree, small-tree, shrub, and herb categories and for regeneration of Nothofagus spp. which are dominant in the canopy throughout. Altitudinal gradients occur in forest composition with a rather marked change near 2,000 ft which is interpreted as a transition from lowland to upland facies of N. menziesii forest. Similar patterns are revealed in the distribution of ground and epiphytic bryophytes. From comparison with studies on Secretary Island and in the Lower Hollyford Valley, it is suggested that Fiordland forests can be regarded as a beech forest continuum, dominated largely by N. menziesii in the upland facies but, in the lowland facies, segregating into different forest types in different areas, probably under environmental pressure.

The altitudinal sequence of climax vegetation on Mt Anglem, Stewart Island

Summary The composition of ground and epiphytic plant communities, consisting mainly cf bryophytes, is recorded in samples from c:ght stands of climax vegetation at different altitudes on Mt Anglem, Stewart Island. Hepatics form at least 40–50% of the total species list in the ground and epiphytic layers of most stands. Ground vegetation was recorded as presence or abscncc data using cither decimetre square quadrats or point quadrats. The abundance of epiphytic spccics was estimated visually and then converted to cover values using empirical conversion constants. Some defects of this technique are discussed. The list of Stewart Island bryophytes compiled by Martin is brought up to date by the inclusion of new records from this study and from other publications.

Some problems in the quantitative ecology of bryophytes

In seeking to understand the interdependence of variables in an ecosystem, the ecologist usually has no more than a spatial pattern of species from which to start (Scott, 1969a). From this pattern he has to deduce which species and which habitat factors are correlated, which are most important to the ecosystem, and which will best repay experimental investigation. For this initial step bryophyte-dominated communities, unduly neglected, have much to oifer, both for their own intrinsic interest and as model systems for investigation. They are compact enough to show pattern on several different scales within easy compass and they are virtually 2-dimensional. Lacking both widespread root-systems and effective cuticular control of transpiration, and with continual maintenance by unspecialised vegetative reproduction, their response to environmental factors, particularly light and humidity, is direct and immediate. Their diversity of pattern thus closely reflects diversity of the micro-environment. For subseque...

New Zealand bryology; Past, present and future

Summary A brief outline is given of the history of bryology in New Zealand, and suggestions are made for further work.