AA_HU_Design Workshop Individual Assignment_Chalk

Chalk: Ecosystem Restoration and Settlment Pattern

Author:

Chun Liu

Programme: MA, Housing and Urbanism

Subject: Design Workshop - The Long Game

Tutor: Lucy Styles

Introduction

Nowadays, about 77 percent of people are living in the urban area, and the percentage is projected to keep growing, and the citizens spend 90 percent of their time indoors in an artificially controlled environment, losing their connection with the natural world as the origin of everything.1

Under the circumstances, the rural spaces always seem to be the areas that provide natural resources for the daily urban process, such as trees becoming timber material, agricultural productions as food, and river and underground water as water supplies. People are only asking for materials from nature, they ignore some original benefits from rural space. Moreover, the overmuch urban requests hurt natural ecology and ecosystems, broke the balance between human beings and nature.

In order to rebuild the balance between urban and rural areas, as well as humans and nature, a new living pattern is raised: plan a self-sufficient community that is motivated by rewilding the environment, find a healthy life and work possibility, which could help people realize their deep relationship with nature. The pattern could also reflect on the five principles put forward by Rewilding Britain,

1. Support people and nature together

2. Let nature lead

3. Create resilient local economies

4. Work at nature’s scale

5. Secure benefits for the long-term2

This essay put forward one of the possibilities under the topic, with the theme of chalk, creating the neighbourhood with chalk streams and chalk grassland ecosystems, and constructing the residence with chalk material. We could explore the possible way to live, work, restore the natural environment of the site, and get income from the life pattern. The potential of the site, the role of settlement contribution, how environmental restoration is beneficial, and the structure of housing are the four crucial levels in the hierarchy.

1. Potential of the riverine site

Under the topic, finding the potential of the site is the first very crucial part, we could see the potential of the site in several aspects, such as its potential for ecosystem restoration, living, and economy. The site is in the southern part of England, along the River Itchen, located between New Alresford and Winchester.

1 Rewilding Britain, "People’s Place In Nature"

2 Rewilding Britain, "Defining Rewilding"

Fig.1-3: Photo of chalk cliff, Adam Wearing Photo of chalk stream, Tim Sykes Photo of chalk grassland, Clem Rutter

I. Ecosystem Restoration Potential

Chalk geology

As we mentioned, ecosystem restoration is one of the motivations for building a rural community under the topic, "freshwaters" and "grasslands, shrublands and savannahs" are the two of the eight ecosystems defined by the United Nations.3 Chalk is particular geology in the United Kingdom, which is a soft, white, porous, sedimentary carbonate rock, creating three special ecologies: chalk streams, chalk grassland, and chalk cliff, two of which are the unique local ecosystems in the "freshwaters" and "grasslands, shrublands and savannahs" category.

Chalk Stream

The chalk stream is one UK local type of river, and there are 210 chalk streams all over the world, 160 of which are in England, fed primarily from the underground water with chalk aquifers because of the permeability of chalk geology. As a result, its water is very clean and barely contains organic matter and sediment, and its flow rate, mineral content, and temperature range have stable seasonal variations. Their stable, cool, nutrient-rich waters support many species, so these habitats are named "England's rainforests". However, such treasure natural resource nowadays faces some problems, such as low water flow because of excessive water usage, pollution, and sediments from farms; according to the State of England's Chalk Streams report, over three-quarters of chalk streams are not in good condition.4

River Itchen is one of the chalk streams that need to deal with the issues, the site of the project is at its good and poor water flow point of intersection between New Alresford and Winchester, the part closer to the seaside is has better water flow, with the river flow's direction from inland to the coast. Several farms produce many river sediments in the upstream area of River Itchen, which causes the river's low water flow and low water quality problems. The site as the downstream area for the farms can potentially recover the chalk stream ecosystem for River Itchen.

Chalk Grassland

The lowland calcareous grassland, also called chalk grassland, could always be found on limestone and chalk valleys in southern England. They are lime-rich but low in nutrients, so the soil only holds little water, preventing the lush grasses from dominating the habitat, which creates a mosaic state for the species with weaker competitiveness, so we could see biodiversity of lower plants and herbs flourish, which also attracts various invertebrate

3 UN Decade, "Types of Ecosystem Restoration"

4 UK Government, "New chalk streams strategy launched to protect ‘England’s rain forests’"

Wikipedia, "Chalk stream"

WWF, "UK Rivers and Chalk Streams"

WWF Report, The State of England’s Chalk Streams

Fig.4: Chalk aquifer distribution in the UK Data source: https://chalkaquiferalliance.wordpress.com/english-chalk-stream-map/ Fig.5: Chalk River's distribution and water flow condition in the UK Data source: 2013 WFD classification for chalk streams, http://assets.wwf.org.uk/downloads/wwf_chalkstreamreport_final_lr.pdf

Fig.6: River distribution and water flow condition in the zooming part Data source: https://chalkaquiferalliance.wordpress.com/english-chalk-stream-map/

Spring Size Information

Summer 3

Water crowfoot Spread: ~0.5m

Height: 10-50cm

Atlantic salmon Weight: ~40kg Lifespan:~13 years

Diet: invertebrates, small fish

Length: 70-80m

Rainbow trout Weight: ~14kg Lifespan: 4-6 years Diet: small fish, insects

Length: 50-70cm

Brook lamprey Weight: ~60g Lifespan: 4-8 years Diet: detritus

White-clawed crayfish Weight: ~90g Lifespan: 8-12 years Diet: water plants...

Length:10-15cm

Southern damselfly Lifespan: 2 years

Flying days: 5-8days Diet: mayflies

Length: 6-12cm

Length: 10cm

Bloom period Plants

Spawn season Animals

Migrant period Invertebrates

Flight period

and insects such as the Adonis Blue and Duke of Burgundy.5 But in the chalk grassland of the site, there are too many trees which take over most of the nutrients of the grassland, so many other lower plants lost their living opportunity in the area. The existed trees also shelter not only the meadows but also streams a lot, which means they deprive the sunshine for the smaller species. Restoring the local chalk grassland to a mosaic status requires biodiversity, which is also the ecosystem restoration potential for the site.

II. Living Potential

In spite of finding the ecosystem restoration potential of the site, we need to focus on its living potential as well. First of all, what could people do with the river? For the recreation aspect, the chalk river and chalk grassland will be beautiful sightseeing for people after its restoration, good sceneries could bring people enjoyment. And fishing is a traditional activity for the chalk rivers, people like Atlantic Salmon and Rainbow trout fishing; the Atlantic Salmon always migrate from the sea to the upstream area in spring and early summer for spawning, while the latter fish is introduced to the chalk rivers in the UK for the fishing industry, people love to stand on the fishing shore or walk into the chalk rivers to catch fish in the particular period in the year, these exciting water activities could also bring people enjoyment and comfort. Secondly, the river in the site has three branches, and they divide the grassland into several parts, which could be the evidence of placing settlements and planning management for different areas.

III. Economic Viability

For the economic viability thinking, as we know, agricultural and farming activities are always the first choice for a rural community to answer the self-sufficiency requirement. However, a large scale of agriculture and grazing practices can hurt the river condition heavily, because the farming activities always bring the soil into the stream water, and the grazing animals need to drink water, they will get many sediments to the river. The sediments do not mean pollution, but the residues influence the water flow, which is one of the significant criteria when we judge the condition of a river. As a result, farming and grazing are not appropriate for the economic viability of a river ecology restoration topic.

Are there any other possibilities of economic potential? The mentioned species of Atlantic salmon and Rainbow trout could be the starting point for the income consideration, and it could be possible to set up a fishing school and fishery industry in the project. Different from agricultural activities, both of them could create resilient local economies for the community, without bringing the River Itchen more possible sediments from farming activities, corresponding to the self-sufficiency requirement of the topic. Furthermore, the site is not very far from the existing settlements, it is close to New Alresford and Winchester, which means it could provide its fishery products to the two nearby towns and attract people from further afield to come and enjoy the fishing activities, not only local people.

5 National Trust, "What's special about chalk grassland?"

water grassland

railway highway road path

train station farm fishing/fishery point

0 1km

Fig.8: Map of Site and surrounding towns, roads, and river

Data source: Digimap

Fig.9: Site analysis diagram: chalk stream flow situation

poor flow good flow chalk stream trees

Fig.10: Site analysis diagram: exising vegetation of the site

Winchester buildings

River Itchen River Itchen

Dropwort Height: 20-50cm Conservation status: common

Pyramid orchid Height: <55cm Conservation status: common

Autumn lady’s tresses Height: 10-15cm Conservation status: vulnerable

Horseshoe Vetch Hight: <20 cm Conservation status: common

Burnet Rose Hight: <50 cm Conservation status: common

Early purple orchid Hight: <40 cm Conservation status: common

Devil's-bit scabious Hight: <75 cm Conservation status: common

Spider orchids Hight: 10-50 cm Conservation status: vulnerable Small scabious Hight: <70 cm Conservation status: common

Monkey orchids Hight: 15-30 cm Conservation status: vulnerable

Adonis Blue

Diet: Horseshoe Vetch Length: 38mm

Chalk Hill Blue

Diet: Horseshoe Vetch Length: 38mm

Spring

Summer

Autumn Winter

4 5 6 7 8 9 11 12 1 2 10

Bloom period caterpillar period Flight period

Fig.11: Local resource analysis diagram, main species in the chalk grassland

However, both the fishing school and fishery could not create a stable income because they are all based on the growth period of the fish; for instance, it is easier to catch Atlantic salmon during its spawn period since they are habituated to spawn back to the upstream area. Tourism could be an alternative for the community, the restored chalk river and grassland could provide unique sceneries to attract visitors, maybe not only tourists but some other organisations restoring chalk ecologies could also pay for visiting. So in the fishing off season, the empty dormitories could be open to the visitors.

2. Role of the settlement

After finding out the potential of the site, exploring the role of settlements in various aspects is also significant. We could treat settlements as a bridge connecting human beings and nature, their organisation, layout, and the working process could be tools to restore the ecosystem and guide human activities.

I. To restore ecosystem

The linear settlements are arranged perpendicular to the streams of the River Itchen, and their combination creates a weave. This organisation could refer to the Cefalu project designed by Vittorio Gregotti, this project locates in the valley. The horizontal megastructures go above and cut the river, which are designed with the upper part of car parks, offices, kindergartens, shops, shopping centres, social centres, and lower structures used as residences.6

Compared with the Cefalu project, the project above River Itchen also uses three linear settlements with different functions to cut the three distributaries. It seems like the three settlement lines create a reasonable hierarchy for the neighbourhood, they not only divide the river into different sections with varying strategies of restoration but also draw the grassland into several parts for management convenience, and the nearest housing units dominate the divided grassland areas. The upper line of housing has the filter function for the River Itchen when its water flows into the community, a longitude filter net is fixed on the elevated bridge of the settlement. The middle line of houses is designed as a fishing school, while the lower line is planned for fishery-relating living and warehouses. Local people who live in different residences have different areas to restore and maintain, all of the local people live in the upper line and lower line, and some of them work in the service centre and cafes of the two collective kitchens of the middle row. The middle and bottom lines of houses are both related to fish, so the two stream segments between two lines could be restored with a small gravel beach, which could show more fishing characteristics for this area and bring people a strong sense of walking to the beach and the chalk stream, corresponding the local chalk fishing culture. In addition, the two

6 Quale Cefalu, "Gregotti e il suo negato Piano per l'edilizia economica e popolare a Cefalù"

Branches of River Itchen Settlement

Sediment filter Chalk grassland Sand and gravel beach

Fig.13: Diagram of weaving concept

Fig.12: Photo for Model of Cefalu residence, Vittorio Gregotti archive

linear accommodations and the two river segments encircle an island area, and the island seems more isolated than other grassland areas, so we could plan this area to grow more vulnerable species of chalk grassland, such as Monkey orchids, Spider orchids, and Autumn lady’s tresses. We could also grow Horseshoe Vetch in the area since it is the diet for most of the chalk grassland butterfly species, so the Horseshoe vetch could attract the butterflies to come and spread pollen for the vulnerable wildflowers to protect them.7

II. For education

The middle line of fishing school with student dormitory and collective kitchen could firstly students coming to learn how to do some special fishing activities. For instance, English cultural chalk stream fishing needs to walk into the streams, and the stream water soaks feet and legs, making people feel relaxed and natural. The collective kitchens in the middle linear residence are right above the branches of the stream, and people could do indoor fishing through the long window. These exciting fishing activities could attract many people to enjoy. So at the same time, it is an excellent chance to invite the students of the fishing school to participate in some eco-friendly activities for restoring the ecosystem, such as cleaning the stream water, sowing various seeds of herbs and small plants on the chalk grassland, and recording the data of species growth condition. So the middle line settlement not only could teach people how to fish but also spread out the importance of ecosystem restoration. Participation could bring people a strong sense of their origin from nature, reinforcing their connection with the environment that has been broken by urbanisation and industrialisation.

7 See Fig.11, Fig.20

III. For self-sufficiency

Considering the rural community should sufficient itself, the layout of the settlement influence the working process. Because the three branches of River Itchen are confluent at the bottom part of the site, the lower linear settlement is designed for the fishery industry to reflect self-sufficiency. The long bridge facing the river confluence provides working space for the fishery, which is broader than the bridges of upper settlements. Different from the indoor fishing activity of the middle line settlement tending to be recreation, the wider bridge is more efficient for the economic process. After finishing the fishery working on the bridge, people do the following process indoors, there is a communal space for every two families, which contains an open kitchen, dining area and fishery working space. The interior collective working space for the fishery has a long table and several professional fridges for storage. The linear residence units beneath the bridge look like the ending edge of the project, which combines the warehouse inside every living unit, so the fishery working process mix with the locals' living.

Self-sufficiency not only means income, but also provides working opportunities and food for the residents. The working opportunities come from teachers and managing the fishing school, daily restoring and data recording activities for chalk stream and chalk grassland, and fishery process. And the fish from the fishery could be the food, obviously. The settlements create the appropriate layout for the process.

3. Environmental restoration beneficial to human

Figure 19 shows the chalk stream restoration strategies and references, most of which are to create shelters and habitats for water animals, such as plating water crowfoot, putting clean gravel, and tree cutting as Logs staked into the riverbed. And other measures are going to create a better fishing environment for people, the gravel beach is a buffer for people to walk in the chalk streams, while people could stand on the log front edge as a fishing platform.

Figure 20 illustrates the mixed planting strategies of the chalk grassland, and it is obvious to see some keys of restoration. The plants and herbs are planned to be mixed based on their height, conservation status, and colour. Zone A are the small hills exposing their chalkland while Zone F is the vulnerable plants' island. The wildflowers of taller height are planted in the outer Zone D of the site as a natural fence of the community; Zone C grows dense Horseshoe Vetch to attract butterflies because it is far from settlements, and Horseshoe Vetch is the diet for most of the chalk grassland butterfly species, so that people will less disturbe butterflies' natural living and working.

Fig.15: Diagram of cutting existing trees

Fig.17: Connectivity

Bridge, stairs, and fishing platform Chalk stream

Fig.16: Diagram of grassland management division

Chalk stream Vegetation Trees plan to cut house I house II house III house IV

area I area II area III area IV

Fig.18: Diagram of building functions

Housing A: narrow house with filter net Housing B: fishing school domitary Housing C: housing for fishery

C Area growing dense Horseshoe Vetch to attract butterflies D Outter area with higher plants as fence E Interbreed area with short plants F Area growing vulnerable species G Common interbreed area H Common interbreed area

Environmental restoration must be a long game to play, and the recovering strategies influence human life more or less. First of all, the sense of restoring participation brings people a sense of belonging, which is essential for a community. Secondly, different recovering measures create different zones with various identities; when people see a massive area with yellow flowers, they could realise that the zone is to attract butterflies; and when they see the gravel beach, they will do activities relating to fishing in the area; when people see most of the wildflowers in the space are purple and tall, they will know they come to the edge of the community. Here natural elements play the role of distinguishing features.

4. Chalk and timber construction

When we look into the construction of the settlement, it uses all the raw materials of chalk and timber from the site, and we could recognise that the materials are all eco-friendly and require less manufacture, resulting in less pollution while producing them. And the structure aims to less hurt the natural environment.

I. How does it touch the ground

Using a regular concrete foundation will break the surface of the land a lot, so the linear houses use a more eco-friendly foundation, which are supported by wooden logs dug many holes into the ground and riverbed, which is less damaging to the environment and avoid using heavy infrastructure construction in the natural environment. Fig.22 illustrates how to make a timber log foundation in the stream. Firstly, remove the gravel and water plants above the riverbed, then use a barrel tool to isolate the area predicting to dig a hole; drain the water. After that, dig a cubic hole and then a deep hole of the same shape as the wooden logs, fill the void with sand once you have inserted the foundation log. Finally, remove the barrel shape isolation, move the gravel and water plants back, and the upper housing structures can be built securely. The construction of the foundation in the river is already simple and environmentally friendly, the ground part foundation will only get easier.

As we mentioned in the former chapters, biodiversity recovery is crucial to the chalk grassland, so the existed trees are not very beneficial to creating the mosaic condition of the chalk grassland. The trees are cut down selectively to reduce their density, some of the cutdown logs become the timber construction material for the housing; some other logs are put inside the river or at the riverside to touch the water, being simple habitats for creatures; and rest of them will be placed at the shore to be the front edge for people staying for fishing.

II. Gap space

In order to minimise the harm to the meadows, the houses are all elevated, there is a gap space between the grassland and the upper housing structure for living and working, so the plants and herbs on the grassland could keep growing in the gap, although there is less sunshine. The linear buildings are also above the streams, meaning that fish could swim and shuttle between the supporting foundation grid of timber logs. The houses could also be artificial shelters for the water animals, which might increase the interest in indoor fishing.

III. Housing construction

The housing is constructed with chalk and timber. Although we could find some historical chalk warehouses and barns in rural England, chalk is recently not so commonly used as

Fig.22: Timber log foundation construction way in the riverbed area

Fig.23-26: Left middle: Photo for North Barn built with chalk in Cerne Abbas, Jo Thomas

Left bottom: Photo for Riverside cottages built with chalk in Litton Cheney, Jo Thomas

Right middle: Photo for Chalk House Private House in Kent, Cassion Castle Architects

Right bottom: Photo for Pines Calyx, Rammed Earth Consulting

a building material. The old chalk structure always used chalk bricks to build up the exterior wall of the building, and they were always not applied to human living due to the high porosity of chalk material, behaving inadequate thermal insulation. But in the cases of Kent Chalk House designed by Cassion Castle Architects and Pines Calyx, they applied the technology of chalk compressed wall, which both keeps the initial characteristics of the chalk rock and improves the practicability of the chalk material. The production process of the chalk compressed wall that refers to Pines Calyx is quite similar to the standard concrete form removal construction process, and the manufacturing process is eco-friendly and low carbon. 1

The bridge uses the timber junctions to support, and then the wooden panel are placed as surface of the bridge, the housing structure is built above the timber structure, whose wall and roof use compressed chalk panels, and the load-bearing structure uses timber columns and beams.

Similar to the timber material source of the project, the chalk material comes from the site as well, a small part of which comes from some chalk wholes dug for housing foundation, most of them are from chalk dug for creating the mosaic grassland with the requirement of bald chalkland. According to the altitude, we could observe from the masterplan that the bald chalkland is created from three small hills on the site, and wildflowers grow denser around the chalkland. In conclusion, digging chalk is both beneficial to building construction and the chalk grassland ecosystem.

Rammed Earth Consulting, "Pines Calyx"

Fig.27-30: Top left: Photo for Compressed chalk wall construction process of Pines Calyx, Rammed Earth Consulting

Top right: Photo for Normal concrete form removal construction process, Chun Liu

Bottom left: Photo for 1: 50 model of Housing A, Chun Liu

Bottom right: Photo for 1: 50 model of Housing A, Chun Liu

1 Cassion Castle Architects, "Chalk House, Private HouseKent"

0 5 10 15m

Fig.31: Housing A plan

Roof construction: -Sheet Copper -bitumen cold bonding agent -Secondary waterproofing -Compressed chalk roof panel 120mm -Insulation boards protect sealing level 50mm -Insulation 130mm -Vapor barrier -Chalk panel ceiling 40mm Total: 340mm

Floor construction: -Compressed chalk panel flooring 45mm -bitumen cold bonding agent -Insulation 80mm -Vapor barrier -Compressed chalk panel 175mm -Timber bridge -Timber log foundation Total: 300mm

Fig.32: Diagram of Housing A-Circulation

Private area Collective area

Domesticity

Water sediment cleaning area Experiment and recording room Warehouse

Fig.33: Diagram of Housing A-Private and collective

0 0.5 1 1.5m

Fig.34: Diagram of Housing A-Function

Fig.35: Section of Housing A

0 5 10 15m 0 5 10 15m

Fig.39: Housing C plan Fig.36: Housing B plan

Fig.37: Diagram of Housing B-Circulation Fig.40: Diagram of Housing C-Circulation

Private area Collective area

Private area Collective area River Itchen River Itchen

Fig.38: Diagram of Housing B-Private and collective Fig.41: Diagram of Housing C-Private and collective

Warehouse

Domitory

Collective kitchen could do indoor fishing Service centre

Working area

Fig.38: Diagram of Housing B-Function

Domesticity

Working and storage area for fishery Dining area

Collective kitchen

Fig.42: Diagram of Housing C-Function

IV. Housing design

The design concept for the three linear settlements is narrow, the Housing A type is narrow houses with a long filtration net hanging on the bridge for filtering the sediment from upstream of River Itchen. The bridge also connects different areas divided by the chalk streams. The service space, kitchen and bathroom are open, and the toilet uses a curtain to keep privacy. The closets and cabinets replace some interior walls, being the space divider. Apart from the residences, one experiment and recording room and two warehouses are designed next to the staircases. The locals always need to monitor the conditions and changes during the restoration process, so they must look at the stream water and grassland soil under a magnifying glass and record the data. The farm tools and wildflower seeds are stored in the warehouse.

Housing B type of the middle line is a dormitory for the fishing school. Four people share a bathroom, a toilet, and a living room in one house. The students of the fishing school cook and eat in the communal kitchen, which is built above the river with a long window, so the students can Stick the fishing rod out of the long window to do indoor fishing in the space, enhancing the enjoyment of their life here. In addition, the students could rent the fishing gear in the service centre, and local people could enter their office and warehouse through the service centre.

Housing C type of the bottom line is a settlement for the fishery, people do fishery on the bridge and then deal with the fish or storage them in the working space on the left side of the collective indoor space. Every two families share one communal room with an open kitchen, dining area and working space. This housing pattern relates human life with their economic working process.

Conclusion

The new living pattern creates a rural community motivated by restoring the environment, finds self-sufficient possibilities with healthy living in the community. We could realise the significance of the following segments when we design a project under the pattern; site potential shows the possible enjoyment of human living; the settlement organises a reasonable and beautiful layout for living and working process, environmental restoration creates good sceneries and better living environment for both human beings and the nature; economic viability brings base and income for people to live here. In this pattern, the design is a practical possibility to recover the balance between humans and nature, and chalk is a great starting point because it relates to both chalk ecology and chalk building materials, and it connects the mentioned parts together fluently. Furthermore, we should keep finding some measures that could both be good for human life and the environment, which is more helpful.

Bibliography: Report

1. WWF Report, The State of England’s Chalk Streams, England: WWF UK, 2014, accessed May 22, 2022, http://assets.wwf.org.uk/downloads/wwf_chalkstreamreport_jan15_forweb.pdf?_ ga=2.247017092.1461907849.1653521468-456905744.1653137436

Website content

1. Cassion Castle Architects, "Chalk House, Private House - Kent", Cassion Castle Architects, accessed May 22, 2022, https://cassioncastle.com/chalk-house

2. Environment Agency, "New chalk streams strategy launched to protect ‘England’s rain forests’", UK Government, October 15, 2021, https://www.gov.uk/government/news/new-chalk-streams-strategylaunched-to-protect-england-s-rain-forests

3. Enzo Cesare, "Gregotti e il suo negato Piano per l'edilizia economica e popolare a Cefalù", Quale Cefalu, March 21,2020, http://www.qualecefalu.it/node/23745

4. Lucy Towers, "How to farm rainbow trout", The Fish Site, June 4, 2010, https://thefishsite.com/articles/ cultured-aquaculture-species-rainbow-trout

5. National Trust, "What's special about chalk grassland?", National Trust, accessed May 22, 2022, https:// www.nationaltrust.org.uk/features/whats-special-about-chalk-grassland

6. Nature Scot, "Atlantic salmon", Nature Scot, accessed May 22, 2022, https://www.nature.scot/plantsanimals-and-fungi/fish/freshwater-fish/atlantic-salmon

7. Northumberland Wildlife Trust, "Atlantic salmon", Northumberland Wildlife Trust, accessed May 22, 2022, https://www.nwt.org.uk/wildlife-explorer/freshwater-fish/atlantic-salmon?gclid=CjwKCAiAgbiQBhAHEiwA uQ6BkqS0n6RIM2pAj2Meu9cOW1Bf6DyJqvrjd3IJU04w6uRsiry5pihv1hoCzkIQAvD_BwE

8. Rammed Earth Consulting, "Pines Calyx", Rammed Earth Consulting, accessed May 22, 2022, http:// rammedearthconsulting.com/rammed-earth-pinescalyx.htm

9. Rewilding Britain, "Defining Rewilding", Rewilding Britain, accessed May 22, 2022, https://rewildingbritain.org.uk/explore-rewilding/what-is-rewilding/defining-rewilding?_ ga=2.197805679.1705808750.1653437142-710877904.1653437142

10. Rewilding Britain, "People’s Place In Nature", Rewilding Britain, accessed May 22, 2022, https:// rewildingbritain.org.uk/explore-rewilding/what-is-rewilding/reconnecting-with-nature

11. UN Decade, "Types of Ecosystem Restoration", UN Decade, accessed May 22, 2022, https://www. decadeonrestoration.org/types-ecosystem-restoration

12. Wikipedia, "Chalk stream", Wikipedia, accessed May 22, 2022, https://en.wikipedia.org/wiki/Chalk_ stream

13. WWF, "UK Rivers and Chalk Streams", WWF, accessed May 22, 2022, https://www.wwf.org.uk/wherewe-work/uk-rivers-and-chalk-streams

Table of figures:

• Cover page: Self-made drawings by Chun Liu

• Fig.1: Adam Wearing, https://www.theguardian.com/news/2021/feb/23/rock-of-ages-how-chalk-made-englandgeology-white-cliffs

• Fig.2: Tim Sykes, https://theconversation.com/chalk-streams-why-englands-rainforests-are-so-rare-and-precious-172827

• Fig.3: Clem Rutter, https://commons.wikimedia.org/wiki/File:DownsRanscombeFieldToMway0734c.JPG

• Fig.4: Self-made drawings by Chun Liu, Data source: https://chalkaquiferalliance.wordpress.com/english-chalk-streammap/

• Fig.5: Self-made drawings by Chun Liu, Data source: 2013 WFD classification for chalk streams, http://assets.wwf.org. uk/downloads/wwf_chalkstreamreport_final_lr.pdf

• Fig.6: Self-made drawings by Chun Liu, Data source: https://chalkaquiferalliance.wordpress.com/english-chalk-streammap/

• Fig.7: Self-made drawings by Chun Liu, Water crowfoot:

Photo source: Zoltan Major, https://blog.thompson-morgan.com/how-green-is-your-pond/ Data source: https://www.wildlifetrusts.org/wildlife-explorer/wildflowers/common-water-crowfoot Atlantic salmon: Photo source: https://www.ereferencedesk.com/resources/state-fish/alaska.html

Data source: https://www.nature.scot/plants-animals-and-fungi/fish/freshwater-fish/atlantic-salmon https://www.nwt.org.uk/wildlife-explorer/freshwater-fish/atlantic-salmon?gclid=CjwKCAiAgbiQBhAHEiwAuQ6BkqS0 n6RIM2pAj2Meu9cOW1Bf6DyJqvrjd3IJU04w6uRsiry5pihv1hoCzkIQAvD_BwE

Rainbow trout: Photo source: Eric Engbretson, https://commons.wikimedia.org/wiki/File:Salmo_trutta.jpg

Data source: https://thefishsite.com/articles/cultured-aquaculture-species-rainbow-trout

Brook lamprey: Photo source: Alamy Stock, https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/animals/fish/brook-lamprey/ Data source: https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/animals/fish/brook-lamprey/ https://canalrivertrust.org.uk/enjoy-the-waterways/fishing/caring-for-our-fish/freshwater-fish-species/rare-and-protectedfish/brook-lamprey

White-clawed crayfish: Photo source: http://www.jhecology.co.uk/services/protected-species-surveys-mitigation-licensing/white-clawedcrayfish-surveys-mitigation-licensing/ Data source: https://www.wildlifetrusts.org/wildlife-explorer/invertebrates/crustacea-centipedes-and-millipedes/whiteclawed-crayfish http://www.habitas.org.uk/priority/species.asp?item=33009#:~:text=Crayfish%20mate%20and%20spawn%20 in,hatch%20in%20May%20or%20June.

Southern damselfly: Photo source: Mike Blacknell, https://www.flickr.com/photos/64271329@N08/49969728146/ Data source: https://www.pebblebedheaths.org.uk/wp-content/uploads/2020/05/PBH-Damselfly-Life-Cycle-reduced. pdf

• Fig.8: Self-made drawings by Chun Liu, Data source: Digimap

• Fig.9-10: Self-made drawings by Chun Liu

• Fig.11: Self-made drawings by Chun Liu

Dropwort:

Photo source: Hugh Mothersole, https://www.nationaltrust.org.uk/chilterns-countryside/features/discover-chalkgrassland-in-the-chilterns-countrysideData source: https://www.naturespot.org.uk/species/dropwort

Pyramid orchid: Photo source: Hugh Mothersole, https://www.nationaltrust.org.uk/chilterns-countryside/features/discover-chalkgrassland-in-the-chilterns-countrysideData source: https://www.wildlifetrusts.org/wildlife-explorer/wildflowers/pyramidal-orchid

Autumn lady’s tresses: Photo source: https://www.plantlife.org.uk/uk/discover-wild-plants-nature/plant-fungi-species/autumn-ladys-tresses Data source:https://www.plantlife.org.uk/uk/discover-wild-plants-nature/plant-fungi-species/autumn-ladys-tresses https://en.wikipedia.org/wiki/Spiranthes_spiralis

Horseshoe Vetch: Photo source: https://www.uksouthwest.net/wildflowers/fabaceae/hippocrepis-comosa.html Data source: https://www.uksouthwest.net/wildflowers/fabaceae/hippocrepis-comosa.html

Burnet Rose: Photo source: https://www.first-nature.com/flowers/rosa-pimpinellifolia.php Data source: https://www.first-nature.com/flowers/rosa-pimpinellifolia.php

Early purple orchid: Photo source: https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/plants/wild-flowers/early-purple-orchid/ Data source: https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/plants/wild-flowers/early-purple-orchid/ https://www.wildlifetrusts.org/wildlife-explorer/wildflowers/early-purple-orchid

Devil's-bit scabious: Photo source: Udo Schmidt, https://plantlife.love-wildflowers.org.uk/wildflower_garden/grow_in_the_garden/devilsbit_scabious Data source: https://plantlife.love-wildflowers.org.uk/wildflower_garden/grow_in_the_garden/devils-bit_scabious Spider orchids: Photo source: Surrey Wildlife Trust, https://mobile.twitter.com/surreywt/status/1394947180042113025 Data source: https://www.plantlife.org.uk/uk/discover-wild-plants-nature/plant-fungi-species/early-spider-orchid Small scabious: Photo source: Roger Darlington, https://wildflowerfinder.org.uk/Flowers/S/Scabious(Small)/Scabious(Small).htm Data source: https://www.gardenersworld.com/plants/scabiosa-columbaria/ Monkey orchids: Photo source: https://www.naturetrek.co.uk/tours/crete Data source: https://www.plantlife.org.uk/uk/discover-wild-plants-nature/plant-fungi-species/monkey-orchid Adonis Blue: Photo source: https://butterfly-conservation.org/butterflies/adonis-blue Data source: https://butterfly-conservation.org/butterflies/adonis-blue Chalk Hill Blue: Photo source: https://butterfly-conservation.org/butterflies/chalk-hill-blue Data source: https://butterfly-conservation.org/butterflies/chalk-hill-blue

• Fig.12: Vittorio Gregotti, https://relationalthought.wordpress.com/2013/05/06/1649/

• Fig.13-18: Self-made drawings by Chun Liu

• Fig.19: Self-made drawings by Chun Liu

Photo source: https://www.wessexrt.org.uk/assets/files/ChalkstreamRestorationExamples--EmailVersion.pdf https://www.orvis.co.uk/pages/one-to-one-personal-tuition-day-river-itchen https://www.aquaplante.fr/plantes-de-bassin/aquaplante-bassin/74822-nymphoides-peltata-panier-plantation11x11cm.html

Data source: https://www.wessexrt.org.uk/assets/files/ChalkstreamRestorationExamples--EmailVersion.pdf

• Fig.20: Self-made drawings by Chun Liu

Photo source: Chun Liu, 2022, Brighton

Ibid Fig.11

• Fig.21-22: Self-made drawings by Chun Liu

• Fig.23-24: Jo Thomas, https://www.dorsetbuildingstone.org/chalk.html

• Fig.25: Cassion Castle Architects, https://cassioncastle.com/chalk-house

• Fig.26-27: Rammed Earth Consulting, http://rammedearthconsulting.com/rammed-earth-pinescalyx.htm

• Fig.28: Chun Liu, 2019, Milan

• Fig.29-30: Chun Liu, 2022, London

• Fig.31-42: Self-made drawings by Chun Liu