The Ordinary Nature of Vegetation by Juntao Jiang by yazid

THE ORDINARY NATURE OF

VEGETATION JUNTAO JIANG S3665298

The Ordinary Nature of ABSTRACT Nowadays, Large-scale urban construction has changed the original natural environment, and it has undergone great threats causing the city to have a heat island effect. In Melbourne where is widely considered as a most livable city worldwide and population booming is expected to expand this city, it becomes necessary to plan for potential problems in advanced. This research is going to explore the possibility of exploiting the existing urban space distribution more effectively to get more tree canopy within the city area and also coordinating the relationship between private and public realms. The space formation in Melbourne central business district area is more likely to be a extremely compact and dense place to create more space for vegetation. As a result, the wisdom to allocate limited space to save financial resources and achieve sustainable goals is going to be a significant element in urban planning aspect. Moreover, Melbourne local governments already define some strategies to work on increasing urban forest canopy and this will be discussed in the article.

VEGETATION 2

CONTENTS

Source: <https://cdn.onlyinyourstate.com/ohio/duck-creek-outdooradventures-summer-oh/?utm_medium=Social&utm_source=Pinterest> 2

OBSERVATION

RESEARCH QUESTION INTRODUCTION

DISCUSSION

LINEAGE MAP

STRATEGY

CONCLUSION

OBSERVATION

FIGURE 2 Location

One of the city center streetscape in Changzhou China, some commercial owners planted some small trees at the door of the store. The lush streetscape trees along the street stand in stark contrast with them. Nowadays, more and more merchants exploit the street frontage as an extension of their own property, planting some private greenery to attract customers or just play a decorative role. It becomes hard to define whether the area is totally private possessed or totally public.

FIGURE 1 Streetscape in changzhou, China

In fact, the city set this street as a vibrant scenic area to attract tourists because it retains the cultural atmosphere of classical architecture. Therefore, the trees here are mostly preserved to provide more space for visitors to enjoy, the other streets may not have so many carefully pruned lush trees.

FIGURE 3

FIGURE 4

Streetscape in Melbourne CBD

Location

Streetscape in Melbourne CBD, there are also some private trees being recognized in some residential backyard. However, the boulevards in the city do not form very dense shadows for pedestrians. Considering Melbourne as one of the most liveable city in the world and extreme weather such as heatwave become more frequent comparing with the past, the author tend to research on if these green infrastructure could response to the challenges such as booming population and extreme weather in near future.

These observation in different cities arouse some consideration about tree density and the quality of providing shade in city including public realm and private space. Due to the boundary between public and private space could be ambiguous in some places so the tree location becomes the decisive factor in determining private or public tree when they are going to be discussed in this article.

RESEARCH QUESTION How to make space use for vegetation more effective through considering private and public space relationship?

FIGURE 5 Size of green spaces per person

INTRODUCTION Over the last century, people quickened their pace of urbanization worldwide owing to industrialization and manufacturing. With booming urban population growing with high-rise buildings in cities, urban residents gradually have awareness of its side effect such as climate change, pollution and biodiversity loss. Humanity realize that they may not be able to survive in these challenges if they take no action. After considering about this, tree canopy within city area becomes relative more important than other factors which can provide shade and take away heat by evaporation during the heatwave. DISCUSSION Hence, the planning for urban green infrastructure becomes an important role in addressing urban development problems. These green spaces in a city could include park preserved areas, sports fields, rivers and river banks, green way trails, community gardens and street trees in the city. Urban green space can help improve many â&#x20AC;&#x2DC;urban diseasesâ&#x20AC;&#x2122; and improve the living environment of urban residents. For example, green vegetation filtering and purifying the air, reducing pollution, reducing noise, cooling, hydrating and providing healthy food for residents. However, in urban areas, the allocation of green space is often unfair. Some former researches prove that the distribution of large amount of urban green spaces will be highly depending on income, race, age, gender, etc. The research is aiming to explore the tree canopy condition in both private and public space and how to ensure the canopy in the city has a increasing tendency which will matter against the background of climate change in subsequent decades.

Tree density in whole Melbourne area reveals that Melbourne central business district has the fewer trees comparing with other suburbs. This may result from it is a highly constructed space, most of the space were occupied by buildings. According to Melbourne urban forest strategy, Melbourne government is trying to increase the amount of trees and also biodiversity within this area to enhance the resilient ability. In Europe standard, people living in the city needs a requirement of at least 5000 square meters within 3 hundred meters distance to have regular activity which is difficult to achieve in CBD because of compact buildings gathering in limited areas. Furthermore, a conference report from World Health Organization points out that the minimum size of green space for residents to keep health is supposed to be more than approximately 9 square meters per person and the ideal size for citizens to live with is about 50 square meters per ca pita.

FIGURE 6 Tree density in city of Melbourne, 1:50000

From the figure, now in the city of Melbourne area general public possess about 487.74 hectares and with a population of 0.18 million in 2019 so the green space individually accessible is about 26.7 square meters and it is seem to be a abundant figure for now. However, Melbourne population is going to witness a rapid growth in next few decades which is expected to increase by 0.38 million in 2041.

At that time the green space per person will shrink to 12.5 square meters which is very close to the minimum standard. Also, the other challenges also gradually emerged, when more statistics were collected. Thanks to urbanization and industrialization, people are attracted to the city centre by profession opportunities and need to commute to work everyday, so that lack of physical activity becomes a major public health risk now. (Farahani, Maller and Phelan, 2019). In Australia, close to half of citizens do not even meet the standard outdoor activity time for 30 minutes every day. One study found that people who use public green spaces are three times more likely to receive recommended levels of physical activity than those who do not. Users and potential users prefer nearby, attractive, larger parks and open spaces (Wolf, 2008).

FIGURE 7 Tree useful life expectancy Looking at Melbourne CBD at a closer view with a lens of useful life expectancy, what can be identified is that most of trees here will be out of their life span within 30 years. This could remind people of a horrible scenario, if local government stay choose to do nothing in 3 decades, Melbourne CBD will just have few trees remained healthy. Fewer trees and short life expectancy in Melbourne CBD will cause problems here getting worse. First, the higher surface temperature in summer could influence local community peopleâ&#x20AC;&#x2122;s well being negatively and decrease the livability in this area for some vulnerable cohort such as elderly who suffer from cardiovascular diseases. Secondly, this could result in the loss of biodiversity which will drag the urban ecosystem into a vicious circle. Less plantings make the other fauna species lose potential food opportunity in the city and lower fauna leads to scarcity of food for people.

FIGURE 8 Tree canopy cover rate

Overlapping the tree density which needs replacement in subsequent 5 years on a canopy cover rate mapping, what can be identified is that in Melbourne central business district, the blocks around the Swanston Street even just several trees could grow there and the blocks from west and east of this street has more trees gathered but these places are where trees has short useful life expectancy there. The smaller tree canopy cover rate compared to other suburbs may caused by the constraints of dense streets and buildings urban configuration. Therefore, the city not only face the obstacles of less tree density, but also the remained trees could have a high possibility being demands for replacing because of the short life span rest, which makes the place becomes a relative problematic place to make some difference for its future. 12

Public space vegetation being made up of trees locating in where most of people can have access in such as streets, roads, parks, squares, reserves and sports fields. These trees mostly were in charged from local government who provide regular maintenance of watering, fertilizer and pruning. The benefit of public trees are they can directly offer shade and fresh air for general public. Private vegetation could be composed by domestic gardens, or some vegetation space not possessed by government entities. These vegetation may not be able to serve everyone, but the advantages of them are not supposed to be ignored by people because majority of space within the city are private property. On the one hand, private vegetation could integrate the scarcity of green spaces in some areas. The domestic garden can configure numerous green space where plants photosynthesize in the sun, absorbing carbon dioxide and generating oxygen. In this way, the oxygen containing in the air created by the function conducted by plantings and this will enhance the quality of urban living environment. On Earth, people or animals are only able to live depending on oxygen at the same time release amount of carbon dioxide. The oxygen that the atmosphere originally stored could be consumed rapidly if no plants remain on this planet. The current situation which not allow people to postpone dealing with them, global temperatures are rising, causing melting ice bergs and bringing about frequent floods and droughts. If there are more vegetation, the surface temperature can be lowered, the heat will be blown away. Moreover, the city has a lot of noise and dust, and the green belt can absorb a large amount of dust, purify the air, reduce noise, prevent various diseases, and create a beneficial living condition. On the other hand, private plantings could bring their owners advantages not just including addressing macro environmental issues, also could become a kind of personal beneficial wealth such as an aesthetic presentation, both enhancing owners physical and mental health. As a result, vegetation spaces are regarded as an indispensable part for sustaining living beingâ&#x20AC;&#x2122;s lives, no matter in public or private spaces.

In Melbourne CBD, the large numbers of buildings in this place are high rise buildings, and residential here are almost apartment buildings. Observing the public and private trees distribution in cbd area, actually the private trees and public trees are all necessary to the whole environment. Private trees could make up the part of vegetation which is scarce in some areas where private property gathering, However, comparing with public trees, the number of private realm trees here still far more less than public realm trees although private property occupied broader area here. In next figure, the view zoom in to look at what happen where trees need instant replacement and at the same time private trees and public trees both grew there. The first selected place is around the corner between Collins Street and Russell Street, in this place the private trees are owned by a local church. It was assumed that these private trees could be preserved for some historical reason which means these trees may have become the urban cultural heritage or as a significant aesthetic element in the field serving for the formation of religion ritual. The second zoom-in place is the west side of melbourne park. These trees grow around tennis court possessed by Tennis Australia. Another space where private trees cluster is on city campus of RMIT University, especially around sports field and leisure places. These preserved private trees in the city area have some common characteristic, they all reserved by private organization and be used as particular functional trees on the open or semi open space. On the contrary, on the centre of bourke street, where commercial stores cluster, for some reason this street just has limited trees, this could be resulted in the stores needs open entrance to the road, and too much trees may block the way and view which related with yield profit. Comparing with private residential in suburbs, in Melbourne CBD area only some large corporate or organization owning private properties where has open space could have the opportunities to planting trees. The rest part due to commercial development, they were all occupied by buildings which is hard to make space for vegetation. FIGURE 9 Tree in public and private realms

URBAN FOREST STRATEGY2012-2032

Lineage map

LOCATION

POLICY

Urban Forest Diversity Guidelines 2011 Green Permit Program 2010 Biotope Area Factor 1997

Green Space Factor 2001

Berlin

Malmö

Open Space Strategy 2012

Future Melbourne 2016 Resilient Melbourne 2016

Growing Green Guide 2014 CENTRAL CITY: Urban Forest Precinct Plan 2013-2023

Seattle Green Factor 2013 Chicago

Melbourne

GREEN OUR CITY STRATEGIC ACTION PLAN 2017–2021 The ordinary nature of tree canopy NATURE IN THE CITY: THRIVING BIODIVERSITY AND HEALTHY ECOSYSTEMS 2017

Melbourne

Seattle

Council House 2 in Melbourne PROJECTS

Burnley living roof

The New Nature 2002

The Dynamic Landscape 2004

Resilience through Regeneration: The Fragmentation- The Biggest Obstacle economics of repurposing vacant land for Biodiversity conservation 2014 with green infrastructure 2018 Green roofs for a wide brown land: Opportunities and barriers for rooftop greening in Australia Cooling cities: Strategies Green roofs as habitats for wild and technologies to mitigate urban heat 2017 plant species in urban landscapes: First insights from a large-scale sampling 2013

Tim Low

Nigel Dunnett and James Hitchmough

Juntao Jiang

Nicholas S.G

INSTITUTIONS

KEY THINKERS

THEORY

Mediterranean open habitat vegetation offers great potential for extensive green roof design 2014

Low Carbon Living CRC

2000’s

2010’s

RMIT 17

STRATEGY When it comes to make space use more effective, ensure the ability of providing enough shadow in the future. Considering the situation of private tree in cbd, the discussion about the method only concentrating on public trees. There are some key factors affecting the quality of these green infrastructure, including species, distance, planting schedule, road formation and so on. Begin with tree species, now Melbourne boulevard trees face the challenges of low biodiversity, usually the single same specie to achieve the sense of order and aesthetic. In central city urban forest precinct plan, it provide other exploration in street trees species selection. Considering the short term and long term goals, the strategy is going to achieve 20 % growth from the existing condition of green space.

Managing assets

Public trees From the figure, what can be seen is local government try their best to change the tree composition of public space, they are working on increasing planting area on streets and in parks. To 2040, the expected number of trees will reach 4200 which is 2 times as the number of existing trees in 2013. The growing number of trees including addition, replacement of park trees and street trees. At the same time, in 2013 the canopy cover rate in all public realm is up to 20 % and canopy cover provided by park only take up about 1 per cent. This cover rate number is expected to approach 30 percent and the additional part is more from canopy in parks which is going to grow by 5% in 2040. FIGURE 10 Tree facts and goals

Source: Mlbourne Urban Forest Strategy <https://www.melbourne.vic.gov.au/SiteCollectionDocuments/urban-forest-strategy. pdf>

FIGURE 11

Managing assets

In 3 different typologies of Melbourne street, these street types seem to be constrained by the tram lines configuration. So where the tram stop located may have a lot of cables which is restricted big plane trees to grow too much branches. One important thing is to think about the distance between the trees, now number of planting bed in some of melbourne streets is low so that cause the lower canopy cover rate in some particular streets. The second thing is mature time, because to ensure the longer useful life expectancy, government tend to replace the old trees with seedling which still need a long period of time to become mature, so in this stage of growth of trees, the entire road is not able to get enough shade. One reasonable strategy is to intercrop seedlings among mature trees which can balance the scarcity in the short time. Last but not least, the selection of species also matters. Although some of street configuration has the restriction of height, canopy width and soil moisture condition. The different species not only can compensate the loss of biodiversity within CBD but also help in fit in the different street types with relative better quality and long lasting shade for pedestrians.

FIGURE 12

On the other hand, open up private open green space for public could bring about some advantages for these cohort. For example, if the merchants on Bourke Street can plant more trees to spare some leisure place for pedestrians, and attracting people to stay in front of their shops which could increase the potential consumers for themselves. In order to spare as much space as possible for green space in private realm, green wall and green rooftop shoud

Tree facts and goals

Precedents

FIGURE 13 Precedents

Precedents

Source: <https://www.forms-surfaces.com/projects/lexington-streetscape>

Private trees In terms of entire precinct, although the private realm trees cannot form the same amount of shade space as the public trees, but in figure, the tendency of potential tree canopy located in private space experience a growing trend during the next few decades. In predictable future, what could be learned from the statistics indicates that the public realm trees will probably be saturated in street area. Hence, the opportunity for private organization to loosen up accessibility to their green space become a potential solution to addressing the limited resources for arbors. (Cameron, 2019) 20

Source: Madreselva Building / Vicca Verde, <https://www.archdaily.com/875111/edificiomadreselva-vicca-verde>

COCLUSION

REFERENCE

The whole vegetation in city could include both the private realm trees and public spaces trees. Public trees could contain street trees and park trees, existing condition in Melbourne seems to be road trees take up the majority in offering shade for general public, and this data shows that the street canopy is close to be saturated and have difficulty in raising the number of new trees. However the potential demonstrate that the park trees still have more possibility in tree growing. In private area, actually

1.Melbourne.vic.gov.au. 2019, URBAN FOREST STRATEGY: Making a great city greener 2012-2032, viewed in 6 May 2019, <https://www. melbourne.vic.gov.au/SiteCollectionDocuments/urban-forest-strategy. pdf> . 2.Melbourne.vic.gov.au. 2019, Central City Urban Forest Precinct Plan 2013-2023, viewed in 6 May 2019, <https://www.melbourne.vic.gov.au/ SiteCollectionDocuments/UFPP_Central_City_Precinct.pdf> .

in suburb where the large area of residential possess big backyard could contribute to the existing urban environment but in the case discussed in the article, Melbourne central business district are more compact and dense here, the large scale of backyard green space to benefit the whole green infrastructure is tricky to become a reality. Although with these limitations, the findings from the figure still shows that the potential to open more private canopy cover is considerable. Subsequently, the focus was transferred to the vegetation in public areas and it still can make some improvements for now engaging with the changes in distance of planting, planting schedule and different species palette. In terms of private realm, it is recommended that local council is supposed to advocate their people of considering about the positive effect of adding more plantings in their property which both benefit themselves and the public, promote activity about raising the awareness of the effect of the strength from tiny actions.

3.Farahani, L., Maller, C. and Phelan, K. (2019). Private Gardens as Urban Greenspaces: Can They Compensate for Poor Greenspace Access in Lower Socioeconomic Neighbourhoods?. [online] Landscapeonline.de. , viewed at 6 May 2019, <https://www.landscapeonline.de/wp-content/uploads/ DOI10.3097-LO201859.pdf> . 4.Troy, A., Grove, J., O’Neil-Dunne, J., Pickett, S. and Cadenasso, M. (2019). Predicting Opportunities for Greening and Patterns of Vegetation on Private Urban Lands. 5.Cameron, R., Blanuša, T., Taylor, J., Salisbury, A., Halstead, A., Henricot, B. and Thompson, K. (2019). The domestic garden – Its contribution to urban green infrastructure.