High altitude ecology: Progress in the study of South Island alpine vegetation
[First paragraphs...]
[First paragraphs...]
[First paragraphs...]
[First paragraph...]
[First paragraphs...]
[First paragraphs...]
In considering the effects produced on pasture areas by infestations of grass grub, it is important to bear in mind certain aspects of its biology:
The insect commonly known as grass grub is the melolonthine beetle (Costelytra zealandica). Other species of the same sub-family are sometimes also found in pasture, especially species of Pyronota (manuka beetle). The economic importance of these is however minor and this paper is concerned solely with C. zealandica.
[First paragraph...]
Without earthworms pasture production may be limited to slightly more than half the true potential. With beneficial earthworms increased production is associated with pronounced physical changes that are, readily observed in the field. Changes in both physical and chemical properties are revealed by analyses of soils from pastures with and without beneficial earthworms. Some of these changes are direct results of earthworm activity, others may be brought about indirectly.
[First paragraph...]
It should not be necessary to emphasise to ecologists the importance of the soil in the pasture ecosystem. Yet it is true that ecologists are not always aware of the limitations of soils with respect to the ecosystem. This is in part because soils are not as easily observed as plants or animals, and in part because of the lack of a course in pedology in the training of ecologists.
[First paragraph...]
In this paper it is intended to describe some aspects of leaf development and leaf canopy structure of communities of two species of importance to New Zealand agriculture in relation to the light environment, then to illustrate some effects grazing has on the grass-legume balance and productivity of pastures.
[First paragraphs...]
[First paragraphs...]
The term "ecosystem" may be defined as "an open system comprising plants, animals, organic residues, atmospheric gases, water and minerals which are involved together in the flow of energy and the circulation of matter".
It is an all-embracing system and this gives it its greatest value-that it is treated as a whole, not as a number of separate parts.