The ecology of tussock grasslands: Some soils of the tussock grasslands
[First paragraph(s)...]
[First paragraph(s)...]
[First paragraph(s)...]
One fifth of New Zealand carries tussock or bunch grass vegetation related to the socalled steppes of the world (1). Tall-tussock grassland has long been distinguished from low-tussock grassland, but further subdivision awaits basic field work. Failing a classification of vegetation types a plant capability survey reviews the restricted range of growth forms present.
[First paragraph(s)...]
[First paragraph(s)...]
The Chairman (DR. FALLA), in initiating the discussion, expressed regret that there had not been further contributions to the symposium dealing in particular with the inter-relationships between flora and fauna of both terrestrial and littoral regions.
[First paragraph(s)...]
[First paragraph(s)...]
Early visits to subantarctic islands were limited to a few days duration and the collecting of specimen material naturally took precedence. Cockayne (1903) and Laing (1909) wrote of the plant formations and associations and gave a remarkably complete picture of the vegetation of the day. Since that time certain aspects of the subantarctic flora have changed considerably although the essential elements are the same. In 1951 Oliver and Sorensen named the associations in accordance with the appearance of the vege- tation 50 years later.
[First paragraph(s)...]
[First paragraph(s)...]
P. B. HANNKEN asked if there was evidence that the fluctuation III the wasp population was not, in fact, an indication of very strong fluctuations which might bring the population back to full strength.
DR. W. COTTIER said he was not certain of the situation, his statement had only been postulation.
[First paragraph(s)...]
It is intended to suggest that there are grounds for the separate consideration of the dynamics of newly introduced species, and further, that there is a need for closer research interest in the dynamics of new populations These aspects are dealt with in general terms.
[First paragraph(s)...]
Whereas experimental patterns of population growth can be satisfactorily determined in the laboratory, their application under field conditions is not easy, although it has been done to a limited extent, e.g., Davidson in Australia on thrips in roses. This contribution is a rather general account of the progress of three newly- introduced species with observations on some factors considered to have influenced population growth. In general the population growth curve of these introductions is shown in the following figure.