University of Sheffield landscape senior lecturer landscape management, ecology and design Cameron said: "We're increasingly disconnected with nature. Horticulture has historically fed the world. It now can act as a catalyst to bring us back in touch with the natural world."
Speaking at RHS Lindley Hall in London, he added: "The future is an urban world. The urban world is dominated by the grey infrastructure, but do we actually want to live in an environment like this?
"We are a biological entity with biological needs. Most species are very habitat dependant."
The holistic value of horticulture to help alleviate the effects of climate change and to help people engage with the natural world needs more emphasis, says Dr Ross Cameron.
The presentation,"Repairing the rift: putting humans back in touch with their own ecology", was about horticulture's role in the ecosystem service delivery - the benefits we derive from the natural world.
He added: "A lack of engagement or understanding of nature and our own basic ecological needs has been coined 'nature deficit disorder'. Indeed, some now argue there is a significant rift between our modern society and our basic ecological and physiological requirements.
Cameron said: "It is important that our cities retain effective green infrastructure to remain functional. It also highlights the fact that horticulturists are well placed to understand the important details of green landscapes and can get the best 'services' out of these places."
He said "symptoms" of this "disorder" can include reduced physical activity and related health issues based around a sedentary lifestyle; a reduction in well-being and increase in mental health problems; fewer social skills; reduced attention span/poorer academic performance; a lack of understanding/appreciation of our own basic environmental requirements (natural cycles, where fresh water/food etc comes from); apathy and an inability to deal with environmental challenges such as climate change; less understanding of or empathy for other species; and a lack of understanding of the value that natural areas and green spaces can provide.
In an urban context this includes combating urban heat islands, improving water quality, reducing the risk of flooding, providing habitat for wildlife, opportunities for recreation and leisure and also directly providing economic gains.
Cameron presented evidence on plants effect on cooling, insulating and flood reducing, for which he said new urban ground cover research showed bergenia, vinca and dianthus had been tested with dianthus showing best results.
He said for noise reducing cedrus was best as a high frequency electrical noise blocker. and photinia as a traffic noise blocker.
On pollinators, he said Aster 'White Wings' had no pollinator visits an hour, while other asters have 15 visits.
And on green roofs, he said tests showed uncovered roofs reached 37 degrees centigrade, the widely reommended sedum 34 degrees, and stachys 22 degrees.
He said a garden with flowers, butterflies and water can be best for psychology so we should be more careful about what to plant. But he added while naturalistic gardens are good for stress-busting, more "inspirational" gardens can help psychology too.
He asked: "To what extent do we still need nature? Can we be more imaginative about our live/work environment? Where does horticulture fit into this urban world?"
Cameron said horticulture needs to be much more radical in its policy ideas and how it pushes them: "Horticulture needs to be more aggressive, abrasive, ambitious to build back ecosystems in urban environment."