14th October 2022
Biodiversity
The natural world and its ecosystems are our life support system providing us with oxygen, clean air, water, food, medicines etc that keeps us all alive. They reduce flooding, even out extreme temperatures, and ensure rainfall. They maintain our well-being – being in nature, seeing blue and/ or green landscapes are known to improve mental and physical health. To diminish the natural world is to diminish what makes life enjoyable and possible. To severely diminish the natural world is to severely compromise life to the point of extinction.
The natural world depends for its vitality on its biodiversity – those the numerous and varied life forms that co-exist in an interconnected web. Reducing biodiversity – whether through the diminution in number of any species or through the extinction of individual species – reduces the health of the natural world and thus the viability of life on this planet.
Do we value the natural environment and its biodiversity? In economic terms do we ascribe to the natural environment – to its natural resources on which we are so dependent – an appropriate financial value? When we build a road do we put a sufficient price on what we will loose through the initial and ongoing damage to the natural environment that it will cause? If we did we might be shocked at how expensive road building is! The WWF calculates the value globally of nature as a capital benefit as being at least US$125 trillion every year. A UK Government study in 2010 reported:-
- The benefits that inland wetlands bring to water quality are worth up to £1.5billion per year to the UK;
- Pollinators are worth £430million per year to British agriculture;
- The amenity benefits of living close to rivers, coasts and other wetlands is worth up to £1.3billion per year to the UK; and
- The health benefits of living with a view of a green space are worth up to £300 per person per year.
Are we, as a nation and a world, encouraging biodiversity and caring for the natural environment? Sadly no.
Scientists working with the Natural History Museum have carried out a survey to measure biodiversity levels across the globe. 100% represents areas where the natural level of biodiversity is intact, where human interaction has not diminished the number or diversity of species. Such areas of pristine biodiversity only exist in remote parts of the Arctic plus a few isolated pockets in the rain forests. At the other extreme there are many areas in, for example the USA, Argentina and New Zealand, where biodiversity has been diminished by nearly 50%. The global average stands at 75%. The safe level – sufficient to guarantee the health and well-being of humans – is 90%!
What causes this loss of biodiversity?
Changes in land use
This includes clearing forests to create plantations or farm land; clearing pasture to create arable land; switching to monocultural farming; digging up hedges; using large tracts of grassland for sheep or cattle (another form of monoculture); clearing vegetation to create mines and quarries. In many places, particularly in Europe the initial change from wild to farm land will have happened a thousand plus years ago – since the 1500s 133 species have become extinct in the UK. However in the last hundred years there has been a marked acceleration in the loss of biodiversity. The State of Nature 2019 report revealed a 41% decline amongst UK species since 1970.
Urbanisation
This is a particular variation of changing land use, and includes not just building houses, commercial and industrial buildings but also transport infrastructure. In Britain the swift population has declined by 38% since 1985 as new and modernised buildings no longer provide suitable nesting spaces.
Buildings and infrastructure not only diminish wildlife habitats, they also fragment existing habitats so preventing species from migrating and/or limiting their gene pools. A rising to the Biologist magazine, everywhere volunteers in Henley on Thames carry upwards of 5000 toads across the A4155 from the ponds where they overwinter to the ponds where they spawn. (https://thebiologist.rsb.org.uk/biologist-features/toads-on-roads)
Pollution
Pollution damages or kills species. Pollution includes not just pollution of water, land and air but also noise pollution. This particularly affects marine creatures. Swift populations have also been affected by the decline in insects. A German study found that insect numbers had declines by 76% since 1990, undoubtably affected by the increasing use of pesticides. The river Wye suffers from excess quantities of phosphates leaking into the river from factory-sized chicken farms that populate the valley. This by-product of chicken faeces kills plants such as water crowfoot, and by taking oxygen from the water, kills local fish and the wildlife that relies on these fish for food, such as kingfishers and otters.
Overkill
Whether hunting or fishing, overkill diminishes numbers right up to the point of extinction, as was seen with beavers (16th century) and wolves (18th century) in the UK. Globally the great auk became extinct in the 1850s (last two were killed in Iceland) and the western black rhino was declared extinct in 2011, whilst only two northern white rhino still exist – both female.
Invasive species
With global travel, non native species have spread around the globe and often proof invasive in their new locations. Japanese knotweed is a particular problem in Britain, whilst rats have threatened wildlife on the Scilly Isles.
Global warming
Many species are sensitive to climate change, and whilst they might overtime be able to adapt or migrate, the speed of change is such that many cannot adapt fast enough and instead decline rapidly in number. Such species include the Adélie penguin in the Antarctic and the North Atlantic cod, as well as alpine plants such as snow pearlwort, drooping saxifrage and mountain sandwort which are all nature to Scotland.
Armed conflict
This is not something we often think of, but armed conflict destroys not just infrastructure but wildlife too and often expended armaments lead to long term pollution of soil, air and water. In marine situations, conflict is a cause of noise pollution too. The Eastern gorilla, which inhabits Congo, Rwanda, and Uganda, is at risk due to fighting in the region. The Ukraine is critical resting spot for migratory birds like the curlew sandpiper. Russia’s invasion of Ukraine coincided with the springtime migration. Fighter jets roared over nature refuges and birds, susceptible to sound, were scared away from their normal resting grounds.
At the Earth Summit held in Rio de Janeiro in 1992 then Convention on Biological Diversity was set up having three main goals: the conservation of biodiversity; the sustainable use of its components; and the fair and equitable sharing of its benefits. In 2010 the signatories of the CBD agreed a set of 20 global targets, with a 10 year time frame, to halt global loss. The Government’s Sixth National Report, published in 2019, showed the UK had missed 14 of its 20 targets.
In 2021 Natural England, Natural Resources Wales, NatureScot, Northern Ireland Environment Agency and the Joint Nature Conservation Committee launched a new report – Nature Positive 2030 – which laid out how the rate of biodiversity loss could be reversed. It called on national and local governments, landowners, businesses and others to:-
- protect existing wildlife habitats – Meadows are one of the rarest habitats in the UK, with 97% of this habitat lost in Britain since World War II. English Heritage properties have some of the last remaining meadows, and is maintaining these to provide much needed habitat for a wide range of flora and fauna such as wildflowers and butterflies. In the Royal Parks, land is being established as wildlife meadows including areas in both Green Park and Hyde Park in central London.
- invest in new habitat restoration projects – of the south coast England’s largest seagrass restoration project has planted around 3.5 hectares of seagrass, whilst another project has planted approximately 1.2 million seagrass seeds across 20,000m2 in Pembrokeshire, Wales. Seagrass provides a vital habitat for a diversity of marine life and an excellent absorber of CO2.
- create nature networks – the Somerset Wildlife Trust recently bought Honeygar Farm in the Avalon Marshes. The aim is to rewild the land as wetland enhancing its biodiversity and increasing the connectivity between nearby nature reserves. The land now forms part of the newly designated “super nature reserve” covering 15,000 acres of the Somerset landscape.
- integrate biodiversity as an integral part of all development plans – the NHBC Foundation, with the RSPB and Barratt Developments has produced a report ‘Biodiversity in new housing developments: creating wildlife-friendly communities’ to show how design concepts, practical solutions and best practice case studies can ensure that new homes are built in a way that enhances wildlife, develops climate resilience, and improves people’s health and wellbeing.
- give preference at every opportunity for nature-based solutions for climate change mitigation – In Richmond’s Old Deer Park, land which regularly floods is to be rewilded with a network of creeks, wetlands, bogs, and reedbeds, a mosaic of wet habitats that could sustain more wildlife and better hold excess river water. This is part of the Thames Landscape Strategy and aims to reduce the extent and impact of flooding in the Thames valley.
Similar projects are and need to be taking place at scale across the globe.
However many countries lack the necessary funding. For others the short-term economics may make it more attractive to sell licenses to rich companies who will exploit the land, than to conserve the biodiversity and natural richness of their land. The provision of external funding for the countries is one of the issues that is to be addressed at the concluding part of COP15 which is due to take place in Montreal this December (the biodiversity COP as opposed to the climate change COP27 taking place in November in Egypt).
It is equally important that wealthy nations do not export its biodiversity loss to lower-income countries – ie if in the UK we rewild agricultural land, we need to ensure that at the same time we restructure our food production to maintain – and ideally improve – our home-grown production rather than just importing more food from other countries to make up any shortfall. In particular this will mean increasing plant based foods and reducing our consumption of animal products. (The former requires far less arable land than the latter).
There is a lot for government and big businesses to do to achieve the necessary improvements in biodiversity but we as individuals through volunteering and fundraising, through petitions and protests, as gardeners and as consumers, can be part of the solution too.
The Green Tau 