The Public Spaces of the Forest-City
Trees First
Tomorrow, we will plant forests in our cities rather than trees. Let’s focus on trees in the city and their needs as a starting point for a better design of public space. Let’s look at the city as a potential forest territory. Let’s establish new public space typologies around tree communities. Forest succession will bring a new temporality and healthy urban living in our densely populated cities.
The Public Spaces of the Forest-City
Trees First
Trees First The Public Spaces of the Forest-City Master of Landscape Architecture Academy of Architecture Author Jean-Franรงois Gauthier Committee Members Jana Crepon (Mentor) Mirjam Koevoet Wiebke Klemm Amsterdam, August, 2019
Index
What is a Forest?
Brussels as a Forest
Where Extremes Meet
14 A Territory
40 Brussels Under Heat Waves
70 The canyon Forest | | BVD Anspach
24 A Community
42 Geographical conditions
88 The Hill forest | Square Anneessens
32 A Time Landscape
44 The Initial Forest
98 The Wetland Forest | Fontainas Park
34 3 Guidelines for the Forest-City
46 The Modern City
118 The Mountain Forest | Brouckere Towers
50 Toward a Forest-City
127 A Matrix for the Forest-City
55 A Hidden Water Structure 58 An Artificial Topography 60 A Pedestrian City Centre 62 A Mosaic of Habitats
A Territory
Wetland Mountain
Experience A Time Landscape
A Community
Canyon Hill
Preface
Trees First My interest in Landscape Architecture started with a fascination for drawings and for the painters from “Barbizon” school, which were the first artists painting “on-site”, in the XIXth century. What strikes me the most is the fact that their only topic was the forest, as if the richness of this environment could never be caught completely and as if the forest was the essence of Art. While doing experimentation myself in the same condition, I realised how difficult it was to draw a tree and how easy it was to paint it. Drawing a tree out of its living context didn’t seem to work while painting it as part of its immediate surrounding seemed right. The painting medium taught me that trees are always connected to their environment and cannot be extracted from it. In landscape architecture; materials, textures and vegetal elements are the basics of our profession. However, the bigger scale brings new layers to deal with. Let’s think of program, car traffic, underground layers, and other pragmatic questions. As a consequence, nature becomes a secondary choice in landscape design. I want to ask myself if a landscape design could be different. Can nature and trees play a leading role in every step of the design process?
6
On-site sketching: first step in my understanding of forest
7
Increase the Tree Cover
A new goal on the urban agenda Increasingly, adding trees to the city is a new goal on the urban agenda in order to fight climate change. Scientific studies explain that trees are our allies to reach sustainable goals such as: - The heat mitigation and the cool island effect thanks to the evapotranspiration phenomena. - The improvement of the air quality thanks to the photosynthesis phenomena and the Co2 absorption. - The resilience of the city thanks to wind, noise protection and the buffering of rain-water. - The increasing of the quality of life and citizen health thanks to the development of nature and biodiversity within the city.
8
News article selection showing the importance of trees in world megalopolis
9
A Change of Attitude
The Concrete-City of Today In European cities, trees are still seen through a utilitarian perspective and as urban furniture. As a consequence, the average life span of a tree in urban conditions is only 30 years. As 75 per cent of the population is expected to live in an urban setting by 2050, a radical approach towards urban nature is needed. Planting trees is not enough; planting forest should become a precondition for a healthy living and urban development.
The Forest-City of Tomorrow Tomorrow, we will plant forests in our cities rather than trees. Cities will adapt to forest plant communities needs. Space will be made for forest succession and spontaneous growth to proceed. Cities will receive great benefits in return in terms of ecosystem services, and urban forests will contribute to public health. In this project, we will focus on trees in the city and their needs as a starting point for a better design of public space.
10
Urban Heat Islands
Pollution Concrete city
Accidental Nature
Controlled Nature Climate Change
Trees as urban furniture
Nature thought ahead
Forest rather than trees
Sustainability Ecology
Purification Physical Experience
Permeable city
Urban Development
11
What is a Forest?
What is a Forest?
An Ecological Definition Looking for a forest definition, one would find hundred of variation, coming from different fields of study such as forestry, literature, landscape architecture or land management. In this project, trees and their ecological needs will be our starting point. To do so, three main themes will help us to give a forest definition. A Territory Environmental conditions define key forest habitats. Trees are adapting specifically to different factors such as the topography, the light, the heat, the hydrology, the soil and the nutrient cycles. A Community A forest is more than a collection of trees competing with each other for light. It is a living organization where trees exchange resources with each other and with animals. Recent book such as The Hidden Life of Trees, explain this new ecological knowledge on forests and their underground social network. A Time Landscape From pioneer stage to climax stage, forests are ever-changing. Ecological succession brings dynamic changes and constant evolution of the plant-community. Walking in the forest, our experience will vary greatly depending on these three themes. In this chapter, we will go through these three themes, and compare forest growth in natural conditions and in urban conditions. In a second time, we will give a definition of the Forest-City, its challenges and its opportunities. Finally, we will define guidelines to build the Forest-City.
14
A Territory Habitats
A Community A Forest
Underground Network
A Time Landscape Ecological Succession
15
A Territory
Natural Conditions “Almost no habitat on Earth offers ideal living conditions [---]. There are many number of difficult sites, and a tree that can get along in such places can conquer an enormous geographic range. Ideal conditions are nowhere to be found and that is a good thing for diversity.” (The Hidden Life of Trees, 2016, p.75).
Urban Conditions “We have to face the fact that many of the species that have been evolving and adapting to the urban environment most successfully are non-native” (Darwin comes to town, 2018, p.179 ).
What is a Forest?
16
Mountain
Plateau
Steep Slope Hill
Canyon
Wetland River
Mountain Plateau Steep Slope Canyon Hill Hill River
Wetland
17
A Territory Environmental Factors
Natural Conditions The adaptation of trees towards very specific conditions result in the formation of forest communities. In every habitat, the light, the heat, the water, the soil and nutrient cycle are key factors for trees development.
Urban Conditions Looking at city habitats, soil is often very compact and the space for roots development is limited. Heat island effect, droughts and floods create extreme urban conditions. Native species are struggling to survive in this harsh environment. Urban habitats studies will allow us to select suitable trees for our city forests. Radical city transformations are required to allow new nature to settle.
What is a Forest?
18
Light and Heat heliophytes
mi-shadow
sciophytes
Water
hygrophytes
mesoxerophytes
mesophytes
Soil and Nutrient
Light and Heat
urban heat island
limited sun
Water
flood and pollution
drought
Soil and Nutrient
impermeability and lack of nutrients compact and covered clay
sandy soil and fast water runoff
19
A Territory Habitat Mosaic
Natural Conditions Challenges coming from the environmental condition define contrasted key forest habitats. Depending on these habitats, forest spatial organisation can varies greatly.
Urban Conditions Human activities have deeply transformed landscapes to create modern cities. Artificial conditions in the city are closer to extreme habitats in natural landscape than to the initial landscape where cities were built. In the new urban conditions extreme habitats can be find next to each other on a small scale. It is an opportunity for a new type of nature to settle in the city.
What is a Forest?
20
Mountain
Plateau
Canyon
Steep Slope
Hill
Wetland
Mountain
Plateau
Canyon
Steep Slope
Hill
Wetland
21
A Territory Ecological Network
Natural Conditions On a broader scale, forest habitats are organised through sources, corridors and stepping stones. Together, these populations form an ecological network and meta-populations as described in the book Landscape ecology principles in landscape architecture. The forest territory is not a uniform landscape but rather a mosaic of habitats. Gradient from open grassland to woodland create dynamics from open to closed space. Edges between habitats are as important as the habitats itself.
Urban Conditions In urban conditions nature is fragmented and highly disturbed by human activities. However, looking at the city as a potential territory, parks could be seen as forest sources; streets could be seen as corridors and squares could be seen as stepping stones. To protect this urban ecological network, the interface between forest communities and public space becomes key and requires design attention.
What is a Forest?
22
Source Stepping stone Corridor
Source
source Park
Corridor Streets
Stepping stone Squares
Source
Forest remains
23
A Community
Natural Conditions As discovered by Suzann Simard in the Architecture of the Wood Wide Web, a forest is an interwoven system rather than a collection of trees. Older trees are connected with each other thanks to underground mycorrhizal networks and share resources and informations.
Urban Conditions “Whereas forests cool themselves on hot summer nights, streets and buildings radiate the heat they soaked up during the day, keeping temperatures elevated [---] Many of the companions that look after trees’ well being in the forest (such as micro-organisms that make humus) are missing. Mychorrhizal fungi that help collect water and food are present only in low numbers. Urban trees, therefore, have to go it alone under the harshest conditions” (The Hidden Life of Trees, 2016, p.175).
What is a Forest?
24
stability: trees supporting each other wind is stopped at the edge
sunlight is not reaching the ground
micro-climate: soil generating humidity in trees shade 50.00m
water absorption is progressive
high and fast transpiration
artificial light
heat reflection
building shadows (reduced photosynthesis) hydrocarbons
limited space for the root system and dry soil
Diagram adapted from the Architecture of the wood-wide web, Kevin J. Beiler, Suzanne Simard
25
A Community Mother Trees
Natural Conditions Mother trees help younger trees from their own species by giving them nutrients through funghi exchange. They bring shade for the seedlings to grow slowly and steadily.
Urban Conditions Urban trees from nurseries are growing solitary, receiving intensive care in their younger years. The contrast with the urban conditions is extremely high in terms of soil quality, access to water and heat. As a consequence, trees from nurseries are not adaptive to the harsh urban conditions they will met when moved to the city.
What is a Forest?
26
genetic diversity
mother tree great photosynthesis
young tree being nursed in the shade
water and sugar exchanges
NURSERY
CITY full sun
Spoiled tree facing harsh city conditions fast growth abundant water
monoculture container
instability and horizontal growth
27
A Community Veteran Trees
Natural Conditions The older a tree gets, the more important it becomes for biodiversity and for the plant-community living around.
Urban Conditions Veteran trees are ideal shelter for the biodiversity we need in our cities (mushrooms, symbiotic bacteria, plants growing on the tree, lichen, moss and animals living around). However, the average life span of a tree in urban conditions is 30 years. It is a design challenge to create better conditions in cities for trees to grow older.
What is a Forest?
28
0
200 - 1600 years
Biodiversity
high potential for urban benefits
average life span of a tree in urban conditions
acceptance 0
27 years
200 - 1600 years
29
A Community The Forest floor - Plant community
Natural Conditions Looking closer to the forest floor, the first 30 cm below ground are the richest thanks to organic material and loose soil. It is also the place for mychorrhization to happen, funghi reach water sources and share it with trees; in exchange trees share produced sugar from photosynthesis. Roots diameters can be 2 to 3 times wider than the tree crown.
Urban Conditions “When trees are planted in these restricted spaces, conflicts are inevitable. [...} When trees in urban areas run up against ground as hard as concrete wherever they turn, they get desperate, and it is only as an absolutely last resort that they finally find a way out into sloppily backfilled trenches.� (The Hidden Life of Trees, 2016, p.175).
What is a Forest?
30
photosynthesis O2
Richer soil in the first 30cm
H2O evapotranspiration
CO2
organic material
water run-off
tree litter mycorrhization infiltration
minerals and water absorption
bedrock
First 30cm covered
unspoiled bedrock
paving on top of the richer soil compact soil
31
A Community Forest Edge
Natural Conditions “At the edge of the forest, the rules for straight trunk growth are not quite strict. Here, light comes in from the side, from a meadow or a lake - places where trees just don’t grow. Smaller trees can get out from under larger ones by growing in the direction of the open area. Deciduous trees, in particular, take advantage of this.” (The Hidden Life of Trees, 2016, p.41).
Urban Conditions At the edge between open and closed habitats, the highest biodiversity can be found. However forest edges are absent in the urban paved areas. As a consequence fauna is limited. Understory is also absent in public spaces. The cool-island effect around trees is therefore less intense.
What is a Forest?
32
30m
50m
30m
Forest Edge
Forest Community
Forest Edge
33
A Time Landscape
Natural Conditions Before reaching a stable social structure, trees are colonizing new areas. In this pioneer stage, Populus, Betula and Salix will grow fast and regenerate the soil. Acer, Fagus, Carpinus, will grow slowly in the shade of the pioneer trees and later replace them. In a climax forest, different succession can be seen next to each other and form a mosaic of stages.
Urban Conditions Dense urban area create fragmentation within woodlands. Pioneer trees are often visible in left-over spaces. Older trees in european capitals can often be seen in private areas such as gardens or cemeteries. If we want to bring back old trees in public spaces, it is important to define clear spaces and borders for trees to grow old. Different urban typologies require different strategies for succession to happen. Depending on the constraints, the maintenance will be higher or lower.
What is a Forest?
34
1 Year: from Annual to Perennial Grasses
10 Years: Pioneer Forest
30 Years: Pioneer Replacement
40 Years: Replacing Forest
90 Years: the First Natural Generation Dies
100 to 200 years: Climax Forest
1 Year: Tree Nurseries
10 Years: City Leftovers
30 years: Street and Square
40 years: Parks
90 years: Courtyard and Garden
Stages Fragmentation
35
3 Guidelines for the Forest-City
Trees First A Territory Urban habitats studies will allow us to select suitable trees for our city forests where extreme habitats can be find next to each other on a small perimeter. It is an opportunity for a new type of nature to settle in the city. A Community The interface and edges between natural areas and public areas is key to protect forest communities from urban disturbance. By creating clear edges, nature is given a holy character. These woodland edges will vary greatly depending on the forest and the urban typologies. A Time Landscape Different urban typologies require different strategies for succession to happen. Depending on urban constraints, the maintenance will be higher or lower. Natural process in public space brings a new temporality and social inclusiveness around urban forest.
A Territory Urban Habitats Mountain Plateau Steep Slope Canyon Hill Hill
River
Wetland
A Community A Forest-City
A Time Landscape Succession Strategies
Dissemination Strategy
Diversification Strategy
Composition Strategy
Vertical Growth Strategy
Minimum Forest
Brussels as a Forest
Brussels as a Forest
The forest-city as dreamt by Brussels inhabitants Rue du Grand-Serment, mural by Brecht Evens
Cities Under Heat Waves What can we do?
In this project, we will take the very centre of Brussels as a case study for an urban forest to settle. As shown in this extract taken from the VRT news, it is urgent to bring nature back in our city-centre:
“Temperatures are rising, especially in the city. Also in Brussels, where parts of the city turn into urban heat islands. Marie-Leen Verdonck is expert in city climate and has studied this theme for years. Marie-Leen Verdonck: Everywhere around us there are buildings and paving, and all this stone absorbs heat. Next to this, there is almost no vegetation, no trees, no grasses. This absence of green makes sure that the city absorbs heat the whole day and in the evening the city becomes a source of heat. All the rough materials are excessing heat during the evening, which ends up in the city cooling down really slowly during the night. Even during late hours at night, the city stays warm and can hardly lose its own heat. When your body is constantly exposed to high temperatures, you will experience a constant feeling of stress, you can hardly concentrate and become easily grumpy. We should really think about how to let green be a bigger part of our cities, creating a more healthy living environment.� Translated from Dutch | VRT news, July 25th, 2019
What is a Forest?
42
Screenshot taken from VRT news, July 25th, 2019
43
Geograhical Condition
The Broad-Leaved Forest Brussels is located between the Northern edge of the Ardennes and the coastal plains of Antwerp. In this area, many small rivers shape a gentle topography before flowing in the Senne which is one of L’Escaut river‘s watershed. These geographical conditions are typical of Western european broad-leaved forests growing in submontane areas, valleys and lowlands.
Brussels as a Forest
44
The Coastal Plain Sea and Scheldt influence in Antwerp
The Central Plateau The Broad leaved Forest: • Gentle topography and side valleys shaping Brussels • River Senne part of the river Escaut watershed
The Northern Edge of the Ardennes Charleroi highlands and Hilly landscape
N
45
The Initial Forest
Natural Conditions Looking closer at Brussels geology, a clear contrast can be noticed between the West and the East part of the Senne River. In the Eastern lowlands, tributaries and sandy-clay soils create conditions for wetland forest to grow. On the West side, the topography is more striking. Limestone hills and plateau define a landscape more suitable for mixed Beech forest. In roman time, the city has been built at the edge between the valley and the higher lands of Brussels West. As a consequence, most of the wetland forests have been cut during the creation of the city.
140 m 60 - 80 m
0 - 20 m
West Wetlands (sand and clay)
Brussels as a Forest
East Hills and Plateau (sand and limestone)
46
N
47
The Modern City
Grey versus Green city Walking in the modern City, is it still possible to experience the initial Brussels forest? Natural remains can still be found in parks located in the tributaries valleys and in forest left-overs in the outskirts of the city (for example the Sonian forest). However, city development has transformed the initial landscape dramatically. The Senne Valley has been completely industrialised. In the city centre, the water system is artificial and the environment is mineral. As a consequence, trees are nowhere to be found in the heart of the city.
Initial Forest Remains
Artificial water cycle
Brussels as a Forest
48
N
49
Opportunity
Heat Island and Impermeability City transformations has led to a dramatic decrease of nature, especially in Brussels city-centre. It is a paradoxical situation, where the initial lifeline of Brussels, the Senne Valley, has become the harshest and driest environment of the city. This is an opportunity as well as a challenge to bring back nature here and to invent new forest typologies serving the resilient city.
Brussels as a Forest
50
N
51
Towards a Forest-City
Where extremes meets In this project area we will focus on the challenging Brussels city-centre and especially on the surrounding of the former Senne river valley. Here, urban transformation has been so radical that extreme potential forest habitats can be found within a very small perimeter. A hidden water system, artificial topography and remains of the initial Brussels valley define a potential forest territory. Different urban situations and very contrasted forest habitats can be found within the perimeter of the Boulevard Anspach and its surroundings. It is an opportunity for a new experience of nature in the most dense part of the city. On a broader scale, it is a chance to study exemplary conditions for Brussels development.
Brussels as a Forest
52
N
53
Project Area
Former Industry | River Senne
Fontainas Park
Brouckère Towers
Annessens Square
Anspach Boulevard
Former Industry | River Senne
Brussels as a Forest
54
Former Industry | River Senne
Brouckère Towers
Anspach Boulevard
Fontainas Park
Annessens Square
Former Industry | River Senne
N
55
A Hidden Water Structure
The Life-line of the City Center? As in many european cities, Brussels Senne river has been covered in the 19th century. Streets in the lowest part of the city follow the river Senne initial water course. In the Boulevard Anspach and Maurice Lemmonier, the river Senne is canalised 1 meter below ground. Its is a combined system mixing rainwater and sewage. By separating rain water and sewage water, there is an opportunity to create a water reservoir for the newly planted forest. At the same time, it will act as a water buffer zone for the city-centre.
River Senne initial water course Canalised River Senne Open-air River Senne
Where Extremes Meet
56
SECTION LINE
N
57
A Water Reservoir for the Forest-City
Proposal Existing situation • A Combined rainwater and sewage system in the lowest part of Brussels Proposal • To separate rain water and sewage water Rain Water Buffer in Winter • A water reservoir for the new forest • A water buffer zone in the lowest part of the city collecting and retaining water from roofs and public spaces • To clean the collected rain water before letting it flow back into the river Senne Cool Island Effect in Summer • Healthy forest and evapotranspiration • A water storage for drought emergency
Where Extremes Meet
58
Existing Situation
Proposal
Rain Water Buffer in Winter
Cool island in Summer
59
An Artificial Topography
Opportunity for New Nature In Brussels, modernist towers were built right next to historical buildings. At the same time, metro lines were constructed and are running right under the city-centre. These urban layers bring a new topography and verticality in the former Senne valley. It creates a “canyon effect� in the centre boulevards and opportunities for new mountain forest habitats to settle.
Modernist Towers M
Metro Station Metro Lines
Where Extremes Meet
60
N
61
A Pedestrian City-Center
Experiment the New Nature Brussels municipality is developing projects to give more space to pedestrian in the city-centre. A plan is being realised to turn Boulevard Anspach into a pedestrian shopping Boulevard. We propose to extend the pedestrian area untill the Boulevard Maurice Lemmonier. The traffic could be reorganised thanks to a loop system. Minimum amount of crossings could be carefully chosen within the future forest area. A peaceful area will allow pedestrian to discover the new nature.
Where Extremes Meet
62
N
63
A Mosaic of Habitats
River Forest
Wetland Forest
Mountain Forest
Hill Forest
Canyon Forest
River Forest
Brussels as a Forest
64
River Forest Former industry
Mountain Forest Brouckère Towers
Canyon Forest Anspach Boulevard Wetland Forest Fontainas Park
Hill Forest Annessens Square
River Forest Former industry
N
65
Where Extremes Meet Boulevard Maurice Lemonnier | Boulevard Anspach
Wetland Forest Mountain Forest Canyon Forest Hill Forest
Where Extremes Meet
A hidden water system, artificial topography and remains of the initial Brussels valley define a potential forest territory. Different urban situations and very contrasted forest habitats can be found within the perimeter of the Boulevard Anspach and its surroundings. Four main forest typologies are defined: the Canyon Forest Boulevard, the Hill Forest Square, the Wetland Forest Park and the Mountain Forest Towers. A green network will be built around these four forest typologies. New urban programmes can be developed around them. Soil continuity and permeability are the precondition for the new forest to settle as well as for the city to become resilient.
Elementary school
The Wetland Forest
Pre-School
The Hill Forest Institut Cooremans Institut Anneessens-Funck
Boulevard Maurice Lemonnier
Boulevard Anspach
Place Fontainas
Palais du Midi
Where Extremes Meet
68
Béguinage
Sainte Catherine
Halles de Saint-Géry
The Mountain Forest
Notre-Dame aux Riches Claires
The Canyon Forest
Place de la Bourse
Place de Brouckère
Boulevard Anspach
Centre Monnaie
Saint Nicolas underground river Senne La Monnaie
The City-Forest
Just like in a forest “meta-population”, the Canyon-Boulevard serves as a “corridor” for fauna and flora, as well as a water reservoir. Thanks to theirs important size, the Mountain-Towers and the Wetland-Park are important “forest sources”. The HillSquare is a “stepping sone” in this networks. Roof-top and green facades can be seen as “forest edges”. Clear edges are defined to protect forest-communities. Soft or hard boundaries around natural areas are created according to the urban pressure. These plant-communities are reacting to the scale of the spaces they settle in. For each habitats, a successions strategy is defined.
Elementary school
The Wetland Forest
Pre-School
The Hill Forest Institut Cooremans Institut Anneessens-Funck
Boulevard Maurice Lemonnier
Boulevard Anspach
Place Fontainas
Palais du Midi
Where Extremes Meet
70
Béguinage
Sainte Catherine
Halles de Saint-Géry
The Mountain Forest
Notre-Dame aux Riches Claires
The Canyon Forest
Place de la Bourse
Place de Brouckère
Boulevard Anspach
Centre Monnaie
Saint Nicolas La Monnaie
The Canyon Forest
A Territory
A Community
• Contrasted seasonal changes from flood to extreme drought
• Linearity and pioneer clumps • Open under-story
• Sandy soil, maximum drainage • Tree roots tolerant to water-logging • Minimum root space • Green Walls • Moisture gradient
Where Extremes Meet
72
A Time-Landscape
Program and Urban Benefits
• Composition Strategy
• Pleasant pedestrian boulevard
• Combining pioneer trees and target species
• Living and shopping area • Water buffer for the city centre • Water squares • Cool island effect from green walls • Ecological corridor
73
The Canyon Forest Boulevard Maurice Lemonnier Sequence 1
Contrasted seasonal changes from flood to extreme drought, green walls, open perspective, sunken forest, clumps and open under-story define the Canyon Forest Boulevard.
underground river Senne
trees in planters boulevard Maurice Lemonnier
metro access car traffic
cafĂŠ
Where Extremes Meet
74
Prunus
A
Aln
Forest Fringe
ndula
Salix alba
The Canyon Forest Boulevard Maurice Lemonnier
M
Alnus glutinosa
Plan Existing - Plan Project
75
The Canyon Forest Boulevard Maurice Lemonnier Sequence 1
The Canyon Forest typology preserves the monumental aspect of the boulevard as the central perspective remains open. Bridges crossing the sunken areas allow people to meet in the centre of the Boulevard where views are kept open. Canyon green walls enhance the historical façades. Pleasant edges and steps between the terraces and the forest clumps allow people to experience the water buffered in the heart of the Boulevard.
boulevard Maurice Lemonnier
monumental perspective
trees in planters
sewage
trees in planters
River Senne collector
cafĂŠs
sewage
Sidewalk
Car Traffic
Sidewalk
5.90
16.70
5.90
Where Extremes Meet
76
green faรงade
retained monumental perspective
Betula pendula Salix aurita
bridge
overflow
2% >
< 2%
gully
Canyon Facade
Pedestrian
Canyon
Pedestrian
1.50
4.50
16.40
6.00
Section Existing - Section Project
77
The Canyon Forest Boulevard Maurice Lemonnier Sequence 2
In this sequence, the Canyon Forest becomes minimum since the metro station is located 1 meter below ground. Swales are created on top of the canalised river Senne which flows along the facades, on both sides of the street.
underground river Senne
cafĂŠ
car traffic
boulevard Maurice Lemonnier
trees in planters cafĂŠ
Where Extremes Meet
78
forest playgrounds Sorbus a
Pre-School
Acer pseudoplat
t Cooremans
Quercus b
Hill Forest e Anneessens
Dryland Vaccinium myrtillus
platanus
Forest Fringe
Tilia cordata
etulus
a
Hotel Barry Café Swales
alba
Betula pendula
Space for Events
Green Façade
Plan Existing - Plan Project
Café
79
The Canyon Forest Boulevard Maurice Lemonnier Sequence 2
In the center of the Boulevard, space for events such as local market is kept. Soil continuity comes from a linear dry prairie meadow. Little by little wild flowers and shrubs will grow and form an early forest succesion in the canyon area.
BVD Maurice Lemonnier
metro access
river Senne collector
metro
sewage
river Senne collector sewage
Sidewalk
Car Traffic
Sidewalk
5.60
16.70
5.60
Where Extremes Meet
80
green faรงade open space for event
swale
Pedestrian
Swale
Dry Meadow
Swale
Pedestrian
4.00
1.60
13.60
1.60
4.00
Section Existing - Section Project
81
The Canyon Forest Place de la Bourse Sequence 3
“Place de la Bourse” is a meeting point for people coming from higher city district and going down to the city-center. It’s also a big metro station and an important space for events and demonstration. Here the canyon effect will be even stronger than in the rest of the Boulevard as the Forest will sunken untill the metro station leel.
M
M
Place de la Bourse
Bourse de Bruxelles
underground river Senne
Where Extremes Meet
82
Sunken Forest
M
Forest Fringe
M Salix aurita
Salix alba Boulevard Anspach
The Canyon Forest Place de la Bourse Large Open Space for Events
Bourse de Bruxelles
Ă&#x2030;glise Saint Nicolas
Plan Existing - Plan Project
83
Where Extremes Meet
84
The Canyon Forest Place de la Bourse Sequence 3
Walking out from the metro, people will already experience the verticality and green walls of the Canton Forest. On the square, nature is well protected thanks to the spatial configuration. Maximum space is kepts for big events on ground floor. The forest canopy becomes an attraction and a landmark.
Place de la Bourse
Metro Access
River Senne collector
sewage
Section Existing
River Senne collector
sewage
85
Platanus orientalis Salix aurita
Metro Access
River Senne collector sewage
Sunken Forest 13.50
Where Extremes Section Meet Existing Boulevard - Section Anspach Project - Place de la Bourse | 1-200e
86
Place de la Bourse Bourse de Bruxelles
Wide Open Space for Events
River Senne collector sewage
Urban Square 48.00
Section Project
87
The Canyon Forest Plant Community
Stones giving stability to trees
Platanus orientalis
Alnus glutinosa
Populus nigra
Canyon Green Wall
Salix aurita
Melissa officinalis
Parietaria erecta
Salix Alba
Urtica dioica
Gradient from dry to wet meadows
Pioneer roots network growing horizontally
Pioneer ability to grow on steep surface
Alnus cordata regenerating soil fertility through symbiotic nitrogen fixation
Where Extremes Meet
88
89
The Canyon Forest Time Landscape
Today: Boulevard Maurice Lemonnier
Pioneer Settlement
Rain Water Buffer in Winter
Cool island in Summer
Where Extremes Meet
90
The Canyon Forest | Development in Time
91
The Hill Forest
A Territory
A Community
• Lowlands and lower slopes of hills
• Tree community at the edge between low and high land
• Space for roots development • Gradient of conditions, from wet to dry
Where Extremes Meet
92
A Time-Landscape
Program and Urban Benefits
• Renewal strategy
• Reinforce urban life (existing cafés, hotel)
• Diversification around Mother Trees
• Cool island in the heart of the city
• Under-story development
• Stepping stone for urban fauna
• Careful tree selection in the secondary succession
• Enhance historical buildings • Move existing market to the Boulevard
• Maintenance close to natural processes
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The Hill Forest
The Hill Forest square can be found at the edge between the valley and higher land; a gradient of moisture defines a specific habitat where Tilia cordata is the key community species.
Tilia roots searching for lose soil in existing situation
underground river Senne
Haute ĂŠcole Francisco Ferrer
Prunus avium
Tilia cordata
hotel Barry metro access boulevard Maurice Lemonnier trees in planters cafĂŠ
Where Extremes Meet
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Institut Cooremans
The Hill Forest Square Anneessens
Vaccinium myrtillus Prunus avium
Acer pseudoplatanus
Forest Fringe
Tilia cordata
Carpinus betulus Alnus glutinosa
M
Swales
Salix alba
CafĂŠ
Plan Existing - Plan Project
Hotel Barry
Space for Events
Green Façade
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Where Extremes Meet
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The Hill Forest
Three steps going down towards the former valley define the hill forest edges, creating a gradient from wet to dry conditions. Three crossing are designed to allow pedestrian to experiment these natural gradients and forest conditions.
boulevard Maurice Lemonnier Haute ĂŠcole Francisco Ferrer
2% >
Section Existing
hotel Barry
car traffic
Sidewalk cafĂŠ
Tilia cordata
Quercus borealis
Haute ĂŠcole Francisco Ferrer
Tilia
Prunus avium Acer pseudoplatanus
Vaccinium myrtillus Crossing and Seating Edge
Pedestrian 12.40
Where Extremes Meet
Dry edge
The Hill Forest
17.50
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Tilia cordata
a cordata
Carpinus betulus Alnus glutinosa Crossing and Seating Edge
hotel Barry Bridge
Seating Edge
River Senne collector
River Senne collector sewage
Section Project
sewage
Wet edge
Pedestrian
37.00
6.00
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The Hill Forest Plant Community
Allium ursinum
Narcissus pseudonarcissus
Tilia cordata
Melampyrum pratense
Prunus avium
Vaccinium corymbosum
Anemone nemorosa
Acer pseudoplatanus
Tilia as mother trees giving nutrients to siblings thanks to mycorrhizal exchange
Dry edge crossing
Bridge
Wet edge crossing
Where Extremes Meet
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The Hill Forest Time Landscape
Today: Tilia cordata as Mother Trees
Enhancing the Hill Forest Habitat
Dry and Wet Edges development
Secondary succession
Where Extremes Meet
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The Hill Forest | Development in Time
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The Wetland Forest
A Territory
A Community
• Lowest part of the city landscape
• Constant moisture
• Island and wetland territory
• Habitat mosaic: valley, wet fringe, plain
• Brussels initial Forest
Where Extremes Meet
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A Time-Landscape
Program and Urban Benefits
• Spreading strategy
• Social Forest (involving schools and inhabitants)
• Natural regeneration Protected and holly islands
• Forest edges cultivated by the inhabitants • New types of sports at the edge of the Forest
• Protecting nature and slowly moving edges • Water sponge for the city • Maximum biodiversity
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The Wetland Forest
The Wetland Forest Park lies in the lowest part of Brussels; it is a mosaic of wet habitat to be found in the plain, the valley and the wet fringes. The main re-creative path cross these different habitats. Parking at the edge of the park are reclaimed and turned into a continuous swale collecting water from the neighbourhoods. A pedestrian loop explores the different forest edges: wetland, playgrounds and food-forest create social interaction between the city and the Forest.
underground river Senne
rue Van Artevelde
buildings recently removed private garden
football
ping-pong tables pre-school basketball
playground
playground institut AnneessensFunck
trade union building playground
place Fontainas
Where Extremes Meet
rue de la Grande Ile
boulevard Anspach
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forest gardens
Alnus glutinosa
forest playgrounds Sorbus aucuparia
Salix alba Salix pentandra
Pre-School
Wetland Acer pseudoplatanus
Quercus borealis
Tilia cordata The Wetland Forest Fontainas Park
Dryland
Institut Annees
Place Fontainas
CafĂŠ
Salix alba Populus nigra
Betula pendula
The C Boule CafĂŠ
Plan Existing - Plan Project
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The Wetland Forest
Thanks to its generous size, the wetland forest is an important forest source in the project area. The park becomes a social forest where time and space is given to inhabitants to experiment natural regenaration and forest dynamics.
Acer pseudoplatanus Sorbus aucuparia
Salix alba
Alnus glutinosa Salix pentandra
Forest Fringe Recreative Path
Pedestrian
Wetland
10.00
74.00
Where Extremes Meet
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Tilia cordata
Quercus borealis
Populus nigra
Entrance
Seating Edge
Dryland
Wetland
Pedestrian
91.00
52.00
12.90
Section Existing - Section Project
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The Wetland Forest Plant Community
Alnus glutinosa
Veteran Trees are ideal shelters for symbiotic bacteria
Lysimachia vulgaris
Mentha aquatica
Iris pseudacorus
Caltha palustris
Equisetum telmateia
Salix Alba
Central path crossing habitats
Later succession occurs in dryer ground
Populus as landmark for the Bouevard
â&#x20AC;&#x153;Ahahâ&#x20AC;? principle as soft border for the park
Where Extremes Meet
110
111
The Wetland Forest Time Landscape
Today: Scattered sports and playgrounds
Celebrating Trees
Pioneer Development
Secondary Succession
Where Extremes Meet
112
The Wetland Forest | Development in Time
113
The Mountain Forest
A Territory
A Community
• Contrasted and extreme conditions
• Communities of specialists
• Steep slope and vertical territory • Limited soil
Where Extremes Meet
114
A Time-Landscape
Program and Urban Benefits
• Vertical growth strategy
• Modernist building to transform (architectural typology with loading capacity) • Governmental offices and shopping centre to reinvent • New public space in the dense city • Collecting rain water and cool island from roof landscape •Fauna development
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The Mountain Forest
The Mountain Forest Towers is a vertical and contrasted territory where very specific tree communities can survive. Modernist towers are ideal structure to be transformed into steep forest territory. Space is reclaimed in the tower. The strict structure of poles and beams is used to create forest space from the ground towards the top of the mountain tower.
Brouckère Tower
Boulevard Anspach
Brouckère Tower
Place de la Monnaie
La Monnaie
Where Extremes Meet
underground river Senne
116
M
Alnus glutinosa
Vertical Forest
The Ca Place d
The Mountain Forest
alba Quercus petraea Pinus nigra
Prunus mahaleb
M
Centre Monnaie
Horizontal forest
Betula pendula
Plan Existing - Plan Project
La Monnaie
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Where Extremes Meet
118
The Mountain Forest
Thanks to their size, spatial configuration and sun orientation, the towers gives opportunities for very specific mountain forest habitats to settle.. From the canyon level to higher elevations, the forest flows into the building horizontally and vertically. New working environment is designed around canyon, caves or grasslands. It is new type of public space, a scale-down landscape system to experience which offers new views on the city-scape.
Section Existing
119
Pinus nigra
Betula pendula
The Vertical Forest
sewage
River Senne collector
sewage
Full Shadow Habitat
Rock Habitat
Mountain Cave Habitat
30.00
49.00
60.00
Where Extremes Meet
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The Horizontal Forest
Betula pendula
Place de la Monnaie
Pinus nigra
Prunus mahaleb
Section Project
Full Sun Habitat
Rock Habitat
27.00
53.00
121
The Wetland Forest Plant Community
Pinus nigra
Prunus mahaleb
Betula pendula
Quercus petraea
Asplenium trichomanis
Epipactus palustris
Asplenium adiantum
Experiencing the vertical forest from soil to camopy
Where Extremes Meet
122
123
The Mountain Forest Time Landscape
Today: Monolith towers
Buildings transformation
Mountain Pionneers
Vertical and Horizontal Growth
Where Extremes Meet
124
The Mountain Forest | Development in Time
125
A Matrix for the Forest-City
A set of design rules is defined from these case studies, exploring key urban habitats, tree communities, succession strategies and urban benefits. These guidelines can become the base for a matrix for the European Forest City.
Where Extremes Meet
126
127
A Matrix for the Forest-City
Where Extremes Meet
128
129
A Change of Attitude
Looking at the city as a potential forest territory, a new type of public space can be invented. It is a process of discoveries for a landscape that can only be met in the city: - The experience of contrasted forest habitats to be found on a very small scale. - The poetry of unknown forest communities finding there ideal landing in the most dense urban areas. - The excitement of an ever-changing picture and atmosphere in the heart of the city. The built programme will have to adapt to the specificities of these new public space creating new opportunities and challenges for architecture, urbanism and landscape architecture. A coherent green-structure can be displayed around key habitats and connect to its bigger scale surroundings. Trees First is a new attitude for urban development, where happy trees meet happy people.
Where Extremes Meet
130
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Acknowledgement and Sources
Working on this topic, I had the chance to learn from inspiring and talented people. Many thanks to: Graduation Committee Jana Crepon | Mentor Mirjam Koevoet | Committee Member Wiebke Klemm | Committee Member Head of Landscape Architecture Maike van Stiphout Hanneke Kijne Experts Hans Kaljee | Expert Urban Forestry Marco Roos | Researcher Urban Biodiversity Michiel Mol | Expert Urban Forestry Regis Ursini | Architect Martin Knuijt | Landscape Architect Pierre-Alexandre Marchevet | Landscape Architect Friends and Family Charlotte van der Woude Koen Hezemans Antonia Cangosz Antoine Thevenet Gaila Costantini Lourdes Barrios Ayala Giuliana Sibilia Florian Fakkert Philippe Allignet Arjan Leenstra Carlijn Klomp Paul Kersten Serge van Berkel Frank Vonk Willian Vonk - de Beer Katharina von Unold Elise Gauthier Sarah Gauthier Paul Gauthier
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New Phytologist
Research
Architecture of the wood-wide web: Rhizopogon spp. genets link multiple Douglas-fir cohorts
Urban trees are thriving
Kevin J. Beiler1,2, Daniel M. Durall1, Suzanne W. Simard2, Sheri A. Maxwell3 and Annette M. Kretzer4 1
Biology and Physical Geography Unit and SARAHS Centre, University of British Columbia Okanagan, Kelowna, BC V1V 1V7, Canada; 2Department of
Forest Sciences, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; 3Department of Biology, University of Western Ontario, London, ON N6A 5B8, Canada; 4SUNY College of Environmental Science and Forestry, Faculty of Environmental and Forest Biology, One Forestry Drive, Syracuse, NY 13210-2788, USA
An explanation of the innovation of the Stockholm soil system Jonathan Nyman
Summary Author for correspondence: Kevin J. Beiler Tel: +1 250 826 1002 Email: Kevin.Beiler@gmail.com Received: 17 June 2009 Accepted: 9 September 2009
New Phytologist (2010) 185: 543–553 doi: 10.1111/j.1469-8137.2009.03069.x
Key words: ectomycorrhizas, forest stability, fungal genet, microsatellites, mycorrhizal network, Pseudotsuga menziesii (Douglasfir), Rhizopogon, stand dynamics.
• The role of mycorrhizal networks in forest dynamics is poorly understood because of the elusiveness of their spatial structure. We mapped the belowground distribution of the fungi Rhizopogon vesiculosus and Rhizopogon vinicolor and interior Douglas-fir trees (Pseudotsuga menziesii var. glauca) to determine the architecture of a mycorrhizal network in a multi-aged old-growth forest. • Rhizopogon spp. mycorrhizas were collected within a 30 · 30 m plot. Trees and fungal genets were identified using multi-locus microsatellite DNA analysis. Tree genotypes from mycorrhizas were matched to reference trees aboveground. Two trees were considered linked if they shared the same fungal genet(s). • The two Rhizopogon species each formed 13–14 genets, each colonizing up to 19 trees in the plot. Rhizopogon vesiculosus genets were larger, occurred at greater depths, and linked more trees than genets of R. vinicolor. Multiple tree cohorts were linked, with young saplings established within the mycorrhizal network of Douglas-fir veterans. A strong positive relationship was found between tree size and connectivity, resulting in a scale-free network architecture with smallworld properties. • This mycorrhizal network architecture suggests an efficient and robust network, where large trees play a foundational role in facilitating conspecific regeneration and stabilizing the ecosystem.
Introduction
Division of Landscape Architecture Department of Urban and Rural Development Master´s Thesis 30 HEC Landscape Architecture Programme – Ultuna Uppsala 2017
Mycorrhizal networks (MNs), or the mycorrhizal fungal mycelia that connect two or more plants, are increasingly recognized as mediators of interactions among trees through their effects on tree survival, growth and competitive ability (Simard & Durall, 2004; Selosse et al., 2006; Whitfield, 2007). Mycorrhizal networks provide a source of mycorrhizal fungal inoculum for establishing seedlings (Finlay & Read, 1986; Nara, 2006), and a potential conduit for interplant transfer of water, carbon and nutrients (Simard et al., 1997; He et al., 2005; Smith & Read, 2008; Warren et al., 2008). Three major challenges of MN research are determining the architecture, function and ecological significance of MNs; considerable debate exists on all levels (Whitfield, 2007). Historically, interest in MNs has focused on their formation and function in
� The Authors (2009) Journal compilation � New Phytologist (2009)
controlled artificial systems (Wu et al., 2001) and in natural ecosystems (Simard et al., 1997; Lerat et al., 2002). However, little remains known regarding the architecture of MNs in the field. Architecture includes the physical components (e.g. nodes and links) of the network and their genetic complexity, the relationships among the components, and the spatial extent and topology of the components and their relationships. Describing these attributes is a prerequisite to understanding how MNs function (e.g. in fungal colonization of plants, mycelial growth dynamics, or nutrient uptake ⁄ exchange between plants) and how they affect plant populations, communities, and forest dynamics (e.g. in tree regeneration, competition and mortality) (Nara & Hogetsu, 2004; Simard & Durall, 2004; Selosse et al., 2006). Network theory provides a useful framework for describing the structure, function and ecology of MNs (Bray, 2003;
New Phytologist (2010) 185: 543–553 543 www.newphytologist.org
Future City 9
Cecil C. Konijnendijk
Issue 1.1/2018
The Forest and the City The Cultural Landscape of Urban Woodland
Written by: Dr Andrew Hirons and Dr Henrik Sjöman
Second Edition Primary Project Funder
Academic Partners
Guidance Sponsors
TDAG
Journal of Landscape Architecture Journal of Landscape Architecture ISSN: 1862-6033 (Print) 2164-604X (Online) Journal homepage: https://www.tandfonline.com/loi/rjla20
The touch of the world: dynamic vegetation studies and embodied knowledge Roland Gustavsson To cite this article: Roland Gustavsson (2009) The touch of the world: dynamic vegetation studies and embodied knowledge, Journal of Landscape Architecture, 4:1, 42-55, DOI: 10.1080/18626033.2009.9723412 To link to this article: https://doi.org/10.1080/18626033.2009.9723412
ISSN: 1862-6033 (Print) 2164-604X (Online) Journal homepage: https://www.tandfonline.com/loi/rjla20
Urban forest and landscape infrastructure: towards a landscape architecture of openendedness Stefan Darlan Boris To cite this article: Stefan Darlan Boris (2012) Urban forest and landscape infrastructure: towards a landscape architecture of open-endedness, Journal of Landscape Architecture, 7:2, 54-59, DOI: 10.1080/18626033.2012.746089 To link to this article: https://doi.org/10.1080/18626033.2012.746089
Published online: 06 Feb 2012. Published online: 30 Nov 2012.
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Abstract
Trees First The Public Spaces of the Forest-City Master of Landscape Architecture Academy of Architecture Author Jean-François Gauthier Committee Members Jana Crepon (Mentor) Mirjam Koevoet Wiebke Klemm Amsterdam, August, 2019
Increasingly, adding trees to the city is a new goal on the urban agenda in order to fight climate change. There is an interesting contrast when looking at the average lifespan of trees in the cities: 30 years. The reason is that trees are still being seen from a utilitarian perspective and as urban furniture in European cities. As 75 per cent of the population is expected to live in an urban setting by 2050, a radical approach towards urban nature is needed. Forest should become a precondition for a healthy living and urban development. Tomorrow, we will plant forests in our cities rather than trees. Cities will adapt to forest plant communities’ needs. Space will be made for forest succession and spontaneous growth to proceed. Cities will receive great benefits in return in terms of ecosystem services, and urban forests will contribute to public health. Let’s focus on trees in the city and their needs as a starting point for a better design of public space. Let’s look at Brussels as a potential forest territory and let’s establish new public space typologies around tree communities. Forest succession will bring a new temporality in the densely populated Belgium capital. This project will take the very centre of Brussels as a case study, which is the most transformed area of the city. A hidden water system, artificial topography and remains of the initial Brussels valley define a potential forest territory. Different urban situations and very contrasted forest habitats can be found within the perimeter of our project area: the Boulevard Anspach and its surroundings. Four main forest typologies are defined: the Canyon Forest Boulevard, the Hill Forest Square, the Wetland Forest Park and the Mountain Forest Towers. A green network is built around these four forest typologies thanks to soil continuity and permeability. New urban programmes can be developed around them. A set of design rules is defined from these case studies, exploring key urban habitats, tree communities, succession strategies and urban benefits. These guidelines can become the base for a matrix for the european Forest City.
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