Managers must be able to illustrate that green spaces are essential for energy, flood alleviation and education if the sector is to survive this age of austerity, sector experts have warned.
Speakers at a Groundwork conference last week said despite compelling arguments and figures on their benefits, parks and other landscapes face massive decline and neglect.
Landscape architect and horticulturist Chris Beardshaw said: "There is a risk that without direct and new funding, austerity and localism will mean that we all start to avoid responsibility for caring for and managing green spaces."
A key to survival is to make sure green spaces are "fit for purpose" instead of historical throwbacks no longer relevant to the community.
"If we can show they are essential for energy, flood alleviation and education, spaces start to assume a much greater function. We need a clear and relevant strategy so green spaces are not considered as land left over or aesthetic luxuries but essential to our social fabric."
Environment expert and University of Manchester emeritus professor John Handley warned of a return to the 1980s when the parks labour force shrunk by 60 per cent in a decade. Cuts mean "impoverished, simplified" landscapes stripped of many of their features.
Landscape consultant Peter Neal added: "Non-statutory services will see a 66 per cent reduction in funding in the next eight years and there is a likelihood some services will see a 90 per cent cut."
But he suggested that the sector is good enough to rise to the challenge, referring to last week's Heritage Lottery Fund conference that compared and contrasted the nation's oldest public park, Birkenhead Park, with the newest, the Olympic Park.
"We were good then and are still good. We have one of the world's best urban parks, created for the Olympics through political will, good funding and incredible skill."
Environmental consultant Alison Millward said the sector could play an increasingly strategic role thanks to recent laws creating local nature partnerships and the Green Infrastructure Partnership. It should also tap up "new kids on the block" such as the NHS by proving it can save a primary care trust £10m through good green spaces. Meanwhile, enlightened companies are investing in landscape at their offices.
Among other topics at the event, held in Manchester Town Hall, several speakers highlighted the pioneering role of Lord Heseltine in environmental regeneration back in the early 1980s. Professor Handley said initiatives such as Liverpool International Garden Festival gave huge impetus to landscape-led regeneration.
Environmentalist Chris Baines said Heseltine's focus on green spaces and the formation of Groundwork acted as a cooling counterpoint to violent urban upheavals such as the 1980s riots.