The sunbeams scarce
molest me with a smile,
|THE IMPORTANCE OF BIODIVERSITY||
Biodiversity has become something of a buzzword in recent years. Around the topic has grown a range of confusing terminology, arguments and acronyms (BAPs, BAPAGs, BUPs, etc.).
Below is set out what we hope is a simple outline of the arguments, which may go some way towards clarifying the subject.
WHAT IS BIODIVERSITY?
Biodiversity, as defined by famous biologist E.O. Wilson, "biological diversity is meant to be all inclusive- it's the genetic based variation of living organisms at all levels, from the variety of genes in populations of single species, through species, on up to the array of natural ecosystems."
WHY IS BIODIVERSITY IMPORTANT?
The sheer diversity of life provides a foundation for the continued existence of a healthy planet. It is a common belief that ecosystems rich in diversity gain greater resilience and are therefore able to recover more readily from stresses such as drought or human-induced habitat damage. When ecosystems are diverse, there is a range of pathways for ecological processes so that, if one is damaged or destroyed, an alternative pathway may be found and the ecosystem recover.
The conservation of biodiversity differs from traditional nature conservation. Biodiversity conservation entails a shift from a reactive attitude - fixing things after they have gone wrong - to a proactive effort, seeking to meet peoples' needs from biological resources, while ensuring the long-term ecological sustainability of Earth's biological wealth. On a global level, this involves not only the protection of wild species and their habitats but also the protection of the genetic diversity of cultivated and domesticated species and their wild relatives.
Nancy Dise, Professor of Environmental Science at Manchester Met. University: "As biodiversity is lost, we are chipping away at the life-support system of the planet. We do not know how much of this damage ecosystems can tolerate before they begin to lose functions like clean water, removal of contaminants and storage of carbon and other greenhouse gases."
BIODIVERSITY AND HEDGEROWS
According to the UK Government advisors on nature conservation, the Joint Nature Conservation Committee (JNCC):
"Hedgerows are the most significant wildlife habitat over large stretches of lowland UK and are an essential refuge for a great many woodland and farmland plants and animals."
Hedgerows are the principal habitat for around 50 existing species of conservation concern in the UK, including 13 globally threatened or rapidly declining species (more than for most other key habitats). They are particularly important for butterflies and moths, farmland birds, bats and dormice. There is an estimated ½ million km of hedgerow in England and Wales, of which 42% (about 154,000 km) are ancient and/or species-rich.
Over 600 plant species, 1500 insects, 65 birds and 20 mammals have been recorded at some time living or feeding in hedgerows. Over 100 species of invertebrates can be found in a typical 20-metre section of hedgerow. Hedgerows adjacent to roads, green lanes, tracks and wooded ground tend to be particularly species-rich.
Hedgerows also act as wildlife corridors for many species, including reptiles and amphibians, allowing movement between other habitats. With modern farming practices fields can be barren deserts; hedgerows often afford the only cover for wildlife over huge areas of countryside.
Since 1945 there has been a drastic loss of hedgerows through removal and neglect throughout the UK, particularly in eastern counties of England. This loss is still continuing. Between 1984 and 1990, the net loss of hedgerow length in England was estimated as 21%, in Scotland 27% and in Wales 25%. This loss was the result of a combination of outright removal (1.7% per annum) and neglect (3.5% pa). In England and Wales the loss continued between 1990 and 1993, with neglect becoming increasingly important and removal less so.
|HOW BIODIVERSITY HAS BEEN LOST IN BRITAIN||
The biggest single factor in Britain for loss of biodiversity has been modern farming practices, introduced since WW2; specifically:
· Neglect (no cutting or laying) leading to hedgerows changing into lines of trees or the development of gaps. This reflects the high cost of modern labour and the loss of traditional skills. Too frequent and badly timed cutting leads to poor habitat conditions, the development of gaps and probable species changes and decline.
· Loss of hedgerow trees through old age and felling, without encouraging replacements; this has been identified as a particular problem by the Tree Council.
· Use of herbicides, pesticides and fertilisers right up to the bases of hedgerows leading to nutrient enrichment and a decline in species diversity.
· Increased stocking rates, particularly of sheep, leading to hedgerow damage and the need to fence fields. The presence of fences reduces the agricultural necessity for hedge maintenance and so hastens their deterioration. The modern practice of "ranching" (placing netting around several fields to form a grazing block) also contributes to the deterioration of internal hedges.
· Careless encouragement of the planting of wildlife unfriendly single species through grant programmes such as the Countryside Stewardship Scheme.
The loss of biodiversity through clearing of hedgerows has contributed to reduction in rainfall retention, salinisation of soils, leaching of nutrients and accelerated erosion of topsoil, decreasing the land's productivity.
|PRACTICAL BIODIVERSITY - HOW BIODIVERSITY CAN BE REGAINED WITH HEDGEROWS||
"Biodiversity begets biodiversity". Biodiversity has a natural tendency to increase; an accumulation of plants, insects, beetles, reptiles, amphibians, small mammals and birds will quickly fill ecological niches and develop a food chain. More plants mean more food, which means more insects, more birds, more reptiles, more mammals, which means more balance.
In order to achieve a sustainable community, a large variety of species is needed to encourage and accelerate the development of a balanced ecosystem; although this will happen eventually by itself, the timescales can be very long.
A biologically diverse hedgerow will quickly produce benefits:
|HOW YOU CAN CREATE BIODIVERSITY IN HEDGEROWS||
To aid the process: in general, the THICKER the hedge, the more wildlife benefit it provides.
· TREES in hedge lines are important for the landscape and help to increase bird, insect and small mammal numbers.
· LARGE VARIETIES of species in hedges mean more FOODSTUFFS will be available throughout the year.
· A WIDE SEPARATION between rows means better SHELTER for animals and a more varied MICROCLIMATE at the base of the hedge.
· UNDERSTOREY species (often rich in nectar) encourage a wide variety of insect life, and quickly establish cover for insects, amphibians, reptiles and small mammals.
· ARTIFICIAL HABITATS (log or rock piles, old pieces of drainpipe or flower pots) speed colonisation.
|BIODIVERSITY: HERE IS WHAT SOME OTHERS THINK||
"The ultimate test
of man's conscience may be his willingness to sacrifice something today
for future generations whose words of thanks will not be heard."
"The diligent farmer
plants trees, of which he himself will never see the fruit."
"To waste, to destroy,
our natural resources, to skin and exhaust the land instead of using it
so as to increase its usefulness, will result in undermining in the days
of our children the very prosperity which we ought by right to hand down
"Each one [of the
Earth's 5 million invertebrate species] plays a role in its ecosystem. It's
like we're tearing the cogs out of a great machine. The machine might work
after you tear out ten cogs, but what happens when you tear out a hundred?"
"A society is defined
not only by what it creates, but by what it refuses to destroy."
"A woodland in
full colour is awesome as a forest fire, a single tree is like a dancing
tongue of flame to warm the heart."
"A nation that
destroys its soils destroys itself."
not just containers, but are processes that change the content totally."
"You can go to
Paris or Beijing and everywhere there's a hamburger bar, the ecological
equivalent of franchised life-forms. Every place is the same place. Kudzu.
Zebra Mussels. Water Hyacinths. Starlings. The local natives, anything unique
gets squeezed out. The only biodiversity we're going to have left is one
soft drink supplier versus another. We're landscaping the whole world one
stupid mistake at a time."
of biodiversity is not just a job for governments. International and non-governmental
organisations, the private sector and each and every individual have a role
to play in changing entrenched outlooks and ending destructive patterns
of behaviour. "
"In nature, there
are neither rewards nor punishments; there are consequences."
depend upon biodiversity for their livelihoods, their quality of life, and
to provide basic ecological services on which all life depends."
"The spirit of
a country, if it is to be true to itself, needs continually to draw great
breaths of inspiration from the simple realities of the country; from the
smell of its soil, the pattern of its fields, the beauty of its scenery
and from the men and women who dwell and toil in the rural areas."
"But while nature
has considerable resilience, there is a limit to how far that resilience
can be stretched. No one knows how close to the limit we are getting. The
darker it gets, the faster we're driving. "
"Don't blow it
- good planets are hard to find."
"We find ourselves
ethically destitute just when, for the first time, we are faced with ultimacy,
the irreversible closing down of the earth's functioning in its major life
systems. Our ethical traditions know how to deal with suicide, homicide
and even genocide, but these traditions collapse entirely when confronted
with biocide, the killing of the life systems of the earth, and geocide,
the devastation of the earth itself."
Richard Mabey: Food
for Free, Collins, 1972