Biodiversity Planning

Irish Version of Site
The Basics of Biodiversity

Many management and maintenance techniques to encourage biodiversity are tailored to particular habitats, types of planting or types of animals. However, there are a number of general principles that underpin many specialised practices, and which apply regardless of the particular location. Athenry Tidy Towns group will actively plan using the following principles

  • You don’t know what you’ve got until it’s gone.
    A fundamental principle of managing sites for biodiversity is to make the most of what is already there. The first thing you should do is study what is in situ in a particular site. A regularly mown grassland may have a lot of wildflowers but these are never given a chance to flower. We must make sure what we already have before changing it.
  • Challenge the myths.
    Myths are not facts. Decisions cannot be made based on myths. An example would be that all birds nest in trees, but many nest on the ground. Many shrubs are planted to benefit bees and butterflies but by removing nettles and many other common shrubs we remove the plants required by caterpillars and other larvae.
  • Keep it appropriate.
     These principles are usually set out in the local Biodiversity Action Plan. To ensure a long term healthy biodiversity we must look at our local ecology. There is no point developing habitats for species that are not in this area.
  • Keep it clean.
    Wildness is often thought to mean leaving nature to look after itself. But it is important to make sure the site does not appear neglected. Litter picking is as important in a wildlife area as in a formal rose bed, but different ways of managing may entail adjustments to the regime, for example, litter needs to be picked before mowing, if cuttings will be composted.
  • Keep it dynamic.
    Standard management practice aims to keep elements of the landscape in the same condition: shrubs are pruned to a regular shape, lawns are close mown to the same height, all self-sown plants are removed from flower beds. Change is therefore limited. Management for biodiversity, on the other hand, may actively encourage change so that more varied opportunities are present for wildlife. Some grasslands might be allowed to change gradually into woodland or shrubs may be pruned less frequently. Many species have no permanent place in a green space managed to suppress all change, yet continuity of habitat is absolutely vital to many species.
  • Size matters.
    Although the quality of a park or green space is not generally dependent on its size, in the context of increasing biodiversity it can often be crucial. Some species, mainly birds and mammals, have minimum area thresholds. So it is important to provide the largest area or mass of habitat wherever possible, as this enhances the chances for species that have large  territories or that are vulnerable to disturbance. This provides the basic rationale to extending biodiversity beyond the bounds of the nature garden and integrating it into the
    wider management of parks and green spaces.
  • Safety in numbers.
    A greater diversity of plants is likely to support a wider range of animals. For example, a wildflower meadow is usually thought to be better for wildlife than areas of unmown, tall
    grassland, because the greater variety of flowering plants supports more nectar-feeding insects than grasses alone. Similarly, a mixed planting of shrubs or a mixed hedge may help encourage more species of birds than a planting or hedge made up of a single species.
  • The sum is bigger than the parts.
    Combining different habitat types together creates a more complex and varied environment for wildlife, because of the larger number of opportunities for shelter and feeding. For example, the song thrush feeds both on invertebrates in open lawns and on berries from hedgerows or woodland edge. Thus, combining areas of short-mown grass with shrubs, hedges and woodland provides all sorts of foraging opportunities as well as
    nesting cover. Rich mosaics of different habitats can also be very attractive to people and are desirable if the size of the site and local circumstances permit.
  • More structure means more diversity.
    The key to providing enhanced habitats for biodiversity is generally increasing the structural diversity of the habitats. For example, long grass meadows provide more
    opportunities than short swards. A woodland with ground flora, dead wood and a small tree layer provides significantly more habitat than one stripped of everything except its
    trees. A survey in England demonstrated a strong correlation between structural diversity and the number of breeding birds present.
  • It’s a matter of life and death.
    We are used to thinking of nature as the living things we can see all around us, whether they are plants or animals. However, biodiversity – the totality of living things – includes also those myriad species that are scarcely visible. Many organisms are involved in death
    and decay and in feeding upon and recycling the dead remains of other life into soil nutrients. Therefore, one of the ways of encouraging greater biodiversity is to encourage this natural recycling by, for example, leaving dead wood on the ground in woodland areas.
  • Life on the edge.
    Biodiversity hotspots often occur at the meeting point between two or more habitats. For example, where a shrubby woodland edge meets tall grass or meadow, plants and animals from both grassland and woodland habitats can thrive. Such boundaries and edges can be
    very useful where space is limited, particularly if allowed to merge rather than maintained as two or more separate areas. They can be especially valuable in warm and sunny aspects where the greatest diversity of wildlife can be expected.
  • Remember the bigger picture.
    It is easy to focus on an individual site or a particular area or feature within that site, to the exclusion of the surrounding area. However, wildlife rarely takes notice of our site boundaries. We should not forget to look at how an individual site fits into a much wider network of spaces and how that connection can be strengthened. We should also consider the role of private gardens, which extend the habitat available for wildlife beyond the public open space.
  • Keep it sustainable.
    Throughout the 20th century, managers of parks and green spaces (as well as the  countryside) often used specific techniques to remove biodiversity, which was seen to be a problem. This later rebounded through the food chain, or caused damage well away from the parks themselves. Adopting more sustainable approaches, for example reducing chemical inputs, water extraction and fertilisers, and avoiding the use of peat, can greatly
    enhance biodiversity.