Eulogy for the trees

November 21, 2022
The North East Link project has levelled a broad strip of remnant bushland at the Simpson Army Barracks. Photo: Warringal Conservation Society

A Funeral for the Environment was organised by Friends of Banyule and Sustainable Cities to mark the North East Link Project’s destruction of the Simpson Army Barracks Forest and its significant habitat in Watsonia.

Below is an abridged version of a speech by Gregory Moore, former Principal of Burnley College of the Institute of Land Food Resources at Melbourne University and a former Senior Lecturer in Plant Science and Arboriculture.

• • •

The trees are gone.

They stood as silent sentinels for decades, and some a century or more, providing environmental and ecological services.

They cooled us in summer, filtered the air we breathe, quietened the noise of the hustle and bustle around us. Their presence increased the value of our homes.

They did all of this at little cost and with less recognition. They helped us live better lives, but now they are gone; cut down in their prime.

Trees and green space are vital for human existence.

Can we really have forgotten that the planet we know as Earth is the earth we know because of plants, trees and green space? Without plants, there would be no life, certainly no human life.

Gone are the trees under which children played with parents and grandparents on balmy summer days. The memories of important family milestones in so many lives persist, but in a generation or two they too will be lost.

They are not the only things that have been lost.

It is curious that, despite knowing that the presence of trees and green space in the vicinity of where you live leads to longer human longevity, better human health and lower state and national health costs, we are still removing trees in our cities and towns.

From a mega-data study on women’s health in the United States, we know that in treed green spaces, women live longer, use fewer proscribed medications, give birth to babies with higher birth weights and are hospitalised less for shorter durations.

When trees are removed they are not the only things that are lost.

Australian research tells us that if there were more treed open spaces available to those living in urbanised areas, a massive $5 billion could be saved from the nation’s annual medical bill for type-2 diabetes, blood pressure and cardiac-related diseases.

The reason for the savings is not rocket science. If treed open spaces are available more people will exercise and these illnesses relate to a lack of physical activity, weight gain and obesity.

When trees are removed unnecessarily, they may not be the only ones who are lost.

Treed open space meets basic human physical, mental and psychological health needs that have their origins in human evolution.

Navigating a large and connected green space engages many senses — sight, hearing, smell and perhaps taste and touch — at once. This activates various parts of the brain and hones a suite of spatial problem-solving skills.

Finding your way requires planning, patience and memory if you have travelled there before: it is multi-tasking par excellence.

These experiences facilitate full human development from infancy to adulthood as the brain’s dopamine secreting neurones are stimulated, impacting motivation, attention and persistence.

Without treed green spaces can we even imagine what else is lost?

Microhabitats lost

Trees sequester carbon and provide diverse microhabitats that may accommodate 50 or more other species.

They are essential to biodiversity and allow humans to connect with nature in urban sites. Without trees the futures of native birds, insects, reptiles and fungi are put at risk too.

When trees are removed they are not the only things that are lost. The health and social benefits of recreation are well-known and the venues for such activities are public open spaces under local government control.

It is easy to think that these facilities bolster urban green space and provide opportunities for greater canopy cover. However more club rooms, car parks and hard surfaces are giving way to a gradual erosion of green space, even within older recreation reserves.

There is enormous pressure on open space to remove trees for more playing surfaces and facilities.

There is no argument against fostering greater participation in recreation, but why is there no strategy for preserving or increasing open green space?

When trees are removed the value of our green space is lost.

There is a strong correlation between the degree of tree canopy cover and the socio economic status of where people live.

Greener, leafier suburbs tend to have a higher socio economic status. People who live in these suburbs are healthier and live longer.

We know it is a correlation, not a simple cause and effect, that crime rates are lower, there is less violence, vandalism and graffiti and educational outcomes at all levels are higher in leafier suburbs.

Greater health benefits accrue to disadvantaged communities from the provision and use of treed open space.

When trees and green space are lost who knows what else we have lost?

Worldwide, the most impoverished sectors are the most disadvantaged in their access to and use of treed open space.

This is true of Australia’s cities, regional centres and many country towns. We can see how disconnected the green patches and corridors of our landscapes and urban environments have become.

It is astonishing to see developments of small blocks and large houses that could have been plucked from the new suburbs of any major city fringing hot, inland towns.

When trees are lost, the potential for coping with climate change is also lost.

Trees play a vital role in making cities sustainable and liveable as climate changes, warms and dries.

The subdivision of older homes involves the loss of mature trees on private land. There is an assumption that these losses will be compensated by street planting. This is pure fantasy: the large old house and block transforms into four townhouses with four driveways which leave little, if any, space in the nature strip for sizeable trees.

A spiral into greater canopy decline starts. The urban heat island (UHI) effect means that parts of cities, regional centres and even smaller towns can experience much higher day and night temperatures than the land that surrounds them.

These higher temperatures, particularly during heat waves, can contribute to higher rates of ambulance callouts, hospitalisation and heat wave related deaths.

Cool cities down

The simplest, easiest and cheapest ways to cool cities is by increasing tree canopy cover.

However, despite knowing the value of tree canopy cover in reducing UHIs, canopy cover is declining in most cities.

The loss in Melbourne is at a rate of 1-1.5% a year, mostly due to trees being removed on private land — front and back yards — for more intense housing development.

This is a serious concern for cities and towns anticipating population rises and future densification.

During the COVID-19 lockdowns, high level concerns about peoples’ physical health, capacities for coping with stress, increased risk of self harm and domestic violence and the learning environments of children, led to people flocking to local parks, gardens and riverside reserves.

Such places became vital in coping with the pandemic.

It also became clear that the most disadvantaged members of the community were further disadvantaged and subjected to higher levels of stress, because of the lack of accessible open space.

There will be future pandemics and one wonders when trees are lost whether the hard lessons of COVID-19 and the importance of treed open space have also been lost.

Research tells us to maximise the benefits provided by trees and their canopy cover. We should be aspiring to a canopy cover of 30%.

However, there is insufficient public space in many municipalities to achieve 30% tree canopy cover and this is further threatened by tree removals. Growing trees on private front and back yards must happen but they too are put at risk by re-development and housing infill.

How is it possible, given rising temperatures that state planning laws continue to ignore the value of trees and open space?

Public parks and gardens served their purpose admirably during lockdowns and, given the opportunity and proper planning, they will do so again, enabling cities to cope with climate change.

Providing large and well-connected treed green space is essential urban infrastructure. They are not as a luxury for a privileged minority, but as a vital component of a sustainable economy for the majority and they are a right for all.

Treed green space is not an option but an essential.

When trees, open space, green space and canopy cover are lost from cities and suburbs, society as a whole has lost.

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