Basin Notes - April 2009

The Tangled Web

The Fabric of Life on earth is a tightly woven mesh of species that live in a delicate balance. This means that it is difficult to say what are the most important species. Many might say plants, as they are the main engine turning sunlight into solid food and providing oxygen for all the other life forms. The workers are undoubtedly the insects, who tirelessly convert plant material into nourishing protein that is vital to so many other species from birds to bears.

Take, for example, a Pipistrelle bat which will consume over 3,000 small insects in a single night. Equally amazing is that in one year in the UK, all the Blue tit chicks consume about 35 billion caterpillars and other small invertebrates.

In addition, many plants rely on insects to pollinate their flowers and so complete their reproductive cycle. Well-known pollinators include bumblebees, honeybees, butterflies and hoverflies. In addition, some less well-known species also provide this service, including moths, thrips, beetles and solitary bees.

This sort of critical relationship was brought into focus recently in some research into the connection between crane-flies (daddy-long-legs) and golden plover. These beautiful moorland breeders have not been doing well over the recent summers because the crane-fly population has declined dramatically. The problem centres on the very hot summers drying out the small water courses that act as the nursery for the next year's crane-flies.

Of course, there are many occasions when the activities of insects intrude on human activities and cause us to reach for some technology to alleviate or eradicate the problem. Of course, when aphids are ruining your garden it is hard to take the long view, but remember that they are provender for ladybirds and hover flies.

Montrose Basin Local Nature Reserve is just like your garden, although gardening design gurus might frown at such a large "water feature". However, there is still weeding, pruning, tidying and planting to be done to keep the Reserve in good condition for wildlife.

Attention has focussed on the reedbeds at the west end of the Basin because, despite tidal action keeping the area "swept" twice a day, improvements to its biodiversity were necessary. Reedbeds are vital habitat for many hundreds of invertebrate species, but to support the maximum range of these beasts the reedbed needs a good mix of age and size of reed and associated plants.

So last autumn staff and volunteers were involved in cutting areas of the reedbed to provide the necessary diverse micro-habitats required for a healthy insect population.

In January this year, the Initiative for Scottish Invertebrates issued a "Strategy for Scottish Invertebrate Conservation" highlighting the plight of invertebrates in the face of habitat loss, habitat fragmentation, climate change, development pressures, competition from non-native species and pollution. It is hoped that nationwide action can be taken to enhance conditions for these unsung heroes of biodiversity.

So if you are keen to have birds and butterflies in your garden, you can help out by providing conditions to encourage insects. Leave some untidy areas with some rotting wood and plant shelters to establish a good population of insect workers in your garden.