London, UK - The poet William Blake described Britain's landscape as a "green and pleasant land" but much of the countryside - from the mighty oak tree to the humble hedgehog - are at serious risk.

Conservation groups and scientists have warned in an alarming report that a staggering 60 percent of UK plant and animal species have declined in recent decades, while more than 10 percent are at risk of being lost entirely.

Intensive farming, sprawling urbanisation and climate change as well as an invasion of species and diseases from abroad are combining in a perfect storm to threaten Britain's fragile natural environment.

The State of Nature, a report compiled by a coalition of 25 conservation groups working together for the first time, warns that wildlife in the UK is under serious threat.

Common species like the lesser spotted woodpecker, barbastelle bat and hedgehog are vanishing before our eyes. -Dr Mark Eaton, conservation scientist

Its lead author, Dr Mark Eaton, a principal conservation scientist at the Royal Society for the Protection of Birds (RSPB), said: "This report reveals that the UK's nature is in trouble - overall we are losing wildlife at an alarming rate. These declines are happening across all countries and UK overseas territories, habitats and species groups, although it is probably greatest amongst insects, such as our moths, butterflies and beetles."

"Other once common species like the lesser spotted woodpecker, barbastelle bat and hedgehog are vanishing before our eyes."

The report examined the distribution of 3,148 mammals, birds, insects and plants and found that 60 percent of species assessed have declined over the past 50 years - 31 percent sharply.

It suggests that recent environmental changes are having a dramatic impact on the UK's land and seas - putting some of the country's most distinctive creatures in jeopardy.

The hedgehog - once a familiar sight in gardens - is disappearing as fast as the tiger with a population decline since the the 1950s of more than 90 percent.

Marina Pacheco, CEO of the Mammal Society, said: "It is astonishing to find that something so ubiquitous can suddenly be under threat. A large part of the problem for hedgehogs is over-development, with our cities becoming denser, more compact, providing less space for animals to move in.

"Hedgehogs are under pressure from humans: it is the pressure of development that's leading to their decline."

Decline across the board

The State of Nature report indicates that the UK has lost in the region of 44 million breeding birds since the late 1960s, including millions of the skylarks that herald the spring dawn.

Among butterflies alone, 72 percent of species have declined over the last 10 years, and the total number of larger British moths fell by 28 percent between 1968 and 2007.

Some native species, such as the stumbling bumblebee are now critically endangered by pollution, the loss of insect-friendly plants in gardens and climate change.

Seven out of eight species of the distinctive British ladybird have been declining rapidly since 2001 as the invasive Asian harlequin species has colonised the country.

Wildlife in Scotland is considered particularly at risk, with five out of 12 seabird species in serious decline and growing fears that wildcats could become extinct within a few years.

Since 1996, harbour seals in Scottish waters have declined by 31 percent.

And it is not just animals that are at risk, with serious threats to some of the established features of British plant life.

The mighty oak, the "King of Trees" and a potent symbol of England with a special place in the country's psyche, is just one established feature of the landscape threatened by invaders.

The oak processionary moth whose caterpillars strip whole trees bare of leaves has taken hold in London since 2006 after oaks were imported from continental Europe.

An invasive fungus that arrived from the continent is also causing the "dieback" of ash trees - crucial components of native woodlands - and in 2012, larvae of the Asian longhorn beetle, which kill oaks and willows, were found in Kent, resulting in 2,000 trees being burned.

The Woodland Trust fears pests and diseases could now threaten most of the country's 115,000 veteran and notable trees - the natural equivalent of listed buildings.

Austin Brady, head of conservation at the Woodland Trust, said: "Losing some trees to diseases and pests is all part of life and death in the forest, but to lose our precious ancient trees would be terrible."

Multiple causes

The threats to UK wildlife are multiple and varied, but modern lifestyles are taking a heavy toll. A significant cause of the threat to wildlife comes from loss of natural habitats due to ever-expanding urban sprawl.

Suburban gardening trends - from the use of paving and decking to an obsession with pet cats - are fuelling the decline. Estimates by the Mammal Society suggest that the UK's cats catch up to 275 million prey a year, of which 55 million are birds.

Poor management of land, forests and fisheries also played a role, as have pollution and wildlife crime. The ploughing, draining and fertilising of grassland has been a major cause of species loss, heathland has been affected by urban development, mineral extraction and afforestation, and the clearing of woodland, pollution and intensive grouse moor management have damaged hills, valleys, moors and mountains.

The intensification of farming driven by a demand for cheap food has left an indelible imprint on the landscape. Farmland birds and butterflies have declined substantially, farmland mammals such as brown hares are ailing, and 14 percent of all farmland flowering plants are threatened - some critically.

Pollution from farmland run-off and water extraction have left many ponds, lakes, rivers, streams, ditches, canals, reservoirs, reedbeds, fens and marshes in a poor condition. Along coastlines, huge areas of saltmarshes, lagoons, mudflats, dunes, shingle, beaches and cliffs have been lost or damaged.

Climate change is also having a discernible impact on British wildlife, particularly in upland and marine environments, and sea-surface temperatures around the UK are rising, changing the distribution of plankton and fish stocks and affecting the breeding success of seabirds.

With numbers in almost three-quarters of UK species at an historically low ebb, any tangible recovery will be more difficult than ever Dr Tom Brereton, Butterfly Conservation

Unusual weather patterns have broken UK records in recent years, prompting the country's top scientists to meet in June. A big freeze gripped Britain in December 2010 pushing temperatures to the lowest for the month in 100 years, and in 2012 a long, wet summer led to the coldest spring this year in 50 years.

The bad weather has played havoc with some species, and in March experts warned that butterflies could disappear from entire parts of the country because of last year's wet weather. In June, the National Trust said winged insects are suffering badly from the late, cold spring.

Dr Tom Brereton, from Butterfly Conservation, said: "2012 was a catastrophic year for almost all of our butterflies, halting progress made through our conservation efforts in recent years. With numbers in almost three-quarters of UK species at an historically low ebb, any tangible recovery will be more difficult than ever."

Non-native species of all kinds have also been invading the UK and spreading northwards in growing numbers, with a potentially devastating effect on native wildlife. More than 27 species of moth, for example, have colonised the UK since as recently as 2000.

Sustained decline

Some colonisers such as the French wasp have crossed the English Channel from continental Europe naturally, but others have been imported. Freshwater invertebrates are at particular risk from the American signal crayfish, introduced to the UK in 1976.

Economic and political factors are heightening the threats to wildlife, say conservationists, who suggest deep cuts to the budget of the Department for Environment, Food and Rural Affairs could have a dramatic impact on their work. Others say a blind emphasis on growth in the UK is undermining European directives to protect biodiversity.

Environmental groups also claim the European Parliament missed a vital chance to safeguard wildlife in reforms to the Common Agricultural Policy - a system of farm subsidies - after farmers successfully watered down plans to compel them to enhance biodiversity on their land.

The authors of the Sate of Nature report are at pains to identify good news stories - targeted conservation efforts that have brought back from the brink a few species such as corncrakes, large blue butterflies and otters.

But they insist that these recoveries have only revived these species to a fraction of their former levels.

Marina Pacheco said that development remains at the heart of the threat to UK wildlife.

"Britain is highly developed and getting more developed. Although we are constantly being told that we want sustainable development, it seems to be more sustained development than sustainable development."

"Unless we do something really clever, I don't see how we can reverse this decline."