Bio-diversity key to survival

Ruapehu Bulletin, Volume 11, Issue 510, 2 November 1993, Page 6

Bio-diversity key to survival

BY

CATHY

JONES,

SENIOR

CONSERV ATION OFFICER (FLORA) DEPARTMENT OF CONSERV ATION.

In conservation these days we often hear of the concept of Bio-diversity. This word may look offputting and scientific to some people or seem to refer to something very complicated and difficult for non-scientific people. Don't let it put you off! It is true that even scientists don't understand all there is to be understood within that concept but anyone can grasp the main idea. Bio-diversity talks about all the various

creatures and plants in nature; how they live together; depend on each other; how the different characteristics of each individual are needed to keep plant and animal communities operating as they should. To help you understand this, just think of human communities: Imagine all the links that one family in a city might have, say, in a week. Links with friends, work-mates, milk-men, rubbish-collectors, shopkeepers, service-station attendants, doctors dentists, customers, schoolteachers. There are hundreds more that we tend not to think about but

rely on like people who maintain our watersupplies and sewerage. The list is endless. We are all different and we all have our part to play in the life of our community. The same is true of communities in nature. Take our native pigeon, the kereru, which relies on the forest to provide it with everything it needs: a place to build a nest; the material to build it with; places to shelter from bad weather; food to eat. Kereru eat the berries from trees such as tawa, miro, pokai whiriwhiri. They eat flowers and young shoots at times of year when fruit is not available. No one

tree can provide all the kereru needs. A varied forest is necessary. Now think about that forest. It relies on the kereru. Many plants have seeds which will grow better if they have passed through a bird's digestive system. Many just rely on the kereru to transport seeds away from the parent tree to new sites. The plants themselves all play different roles in the forest. In an area which has been recently disturbed, where perhaps a big old tree has fallen over or there has been a landslide, tiny plants will grow. Lichens, mosses and algae will cover the ground

along with plants like tutu which take nitrogen from the atmosphere and enrich the soil so that other plants can grow. Then come shrubs and small trees like karamu and five-finger. Birds enjoy the seeds and fruit of these plants and while eating them, bring in the seeds of larger trees. The seedlings of the larger trees grow slowly and require shade in their early years. They are sheltered by faster-growing but smaller and shorterlived light-loving shrubs. When these shrubs are over-topped by trees they are shaded out and are gradually replaced by other shrubs which like to grow

in the shade. Roles are reversed and the tall trees shelter the under-storey shrubs which do their share by adding to the leaf-litter, keeping the forest floor moist and stopping wind from blowing around the trunks of the big trees. These are only a very 'few of the connections which occur but it begins to show how important it is to look after all the individual members of a community so that the whole community can continue to function with all the richness and variation that it has now. The same, of course, applies to the plants and animals which live in any area whether it is wet-land, tussock-land, farm-land or even your back-yard. All this and more is what we mean when we talk about maintaining bio- ' diversity. So you can see why, at times, it is easier to use one all-encompassing word.