Table of Contents
What You Will Do
- Learn what determines (and changes) climate.
- Begin to find, change, and create microclimates.
- Understand how to consider the challenge of climate change within your designs.
- Identify the basic vocabulary of ecosystems and their components.
- Understand the flow of nutrients, energy, and relationships through the ecosystem.
We open this module with a word from our elders
Science helps us to be better designers.
Before we can get too deep into designing to make best use of microclimates and natural patterns, we need to develop a basic understanding of where we are, how the life cycles and food webs function, and what natural limitations and opportunities we can reasonable expect to find.
This information can help us make important decisions about plants, animals, placement, water use, building materials, and so much more. This module will give you an understanding of climate and microclimate and what you need to know as a designer for optimum results. We’ll also make an introductory foray into ecology, ecosystems, energy and nutrient flow.
If this science-y stuff is new to you, use this handout to familiarize yourself with the terms you will come across in this module.
Climate Systems 101
This section by Klaudia Van Gool
The word climate originates from the Greek word klima which means inclination, and refers to the tilting of the Earth. Climate factors include: precipitation, wind and radiation.
Climate is defined as weather changes over a long period of time for at least 30 years. The Climate System refers to how the atmosphere interacts with oceans, ice sheets, landmasses and vegetation. It is driven by the sun.
To understand how this works, it’s easier to see it, so here’s a short video by the UK Met Office. It also explains the seasons on the Northern and Southern Hemispheres.
Climate vs. Weather
Weather is the elements received daily. They can change hour by hour and day by day, and include differences such as temperature, rain and wind. The weather can vary considerably within a climate region.
We use climate zones to show how climate varies across the globe. The most recently identified zones are known as the Trewartha climate classification. These were developed from the earlier Köppen Geiger climate classification which is based on average monthly values of temperature and precipitation.
Climate and climate zones are important because they impact how people live and what can be grown. Techniques that work in one climate zone may not work, or may even have disastrous consequences, in another climate zone.
This is why ecological design is not a set of techniques, but rather a way of understanding how things work together in different places. While we can affect local microclimates (and you will be learning more about this!), the weather patterns of the climate zone you live in is not something you can change as part of your design.
However, considering adaptations and mitigations to cope with the changing climate may well be useful and necessary, and how climate change affects your area will also depend to some extent on your climate zone.
Here’s a map showing what these zones look like. You may notice overlap between the climate zones on the map below and the biomes map in the Local Ecosystems module. This is normal since biomes are affected by climate. However, remember that biomes are defined by vegetation more so than by climate, so their boundaries look different.
Hardiness zones
Another kind of zone is hardiness zones, which are a geographically defined area in which a specific category of plant life is capable of growing, as defined by climatic conditions, including its ability to withstand the minimum temperatures of the zone.
This helps us to make the right plant choices, although they may need to be adjusted if you’re in a coastal area, as the water modifies temperature extremes, so it may not freeze in an area where hardiness zones state it should.
Regional climate
There are regional climate differences for example between coastal and inland, different altitudes and between country and town. As designers, it is important to know the patterns of winds, precipitation and temperature throughout the year. The prevailing wind is the wind from the direction that is predominant or most usual at a particular place or season. Wind rose plot diagrams (below) provide a useful way to identify wind direction and speeds in a particular region. Local measurements using wind vanes and observing local vegetation are important as they help to determine local conditions.
For example, the wind changes direction during the day in coastal regions. This is called the diurnal wind change. The wind also tends to be stronger in a coastal area.
Water bodies modify temperature on all scales, from sea and land mass scale, to a water tank in a greenhouse scale.
When designing, it is important to know the patterns of winds, precipitation and temperature throughout the year.
The prevailing wind is the wind from the direction that is predominant or most usual at a particular place or season.
Wind rose plot diagrams provide a useful way to identify wind direction and speeds in a particular region.
Local measurements using wind vanes and observing local vegetation are important as they help to determine local conditions.
Historical and average weather data such as rainfall, temperature and wind rose charts are readily available via the internet. While identifying a site’s total annual data is important, obtaining monthly data can provide a clearer understanding of how temperatures, rainfall and wind patterns change throughout the year. Reliable weather data can be accessed online through national meteorology services such as USA and UK examples.
Climate and microclimate data and observations are crucial when we are looking for an ideal site for our home/project. We need to consider such things as: protection from wind, aspect of the land, and the direction the house is faced, so we can optimize passive solar energy, except in very hot climates, where keeping a house cool is more important. We’ll go deeper into understanding solar aspect and considerations for buildings such as houses in the Built Environment module.
Knowing our local climate classification is really useful as it makes it easy to identify climate analogues. These are locations around the world with a similar climate. Researching your climate analogues is a great way to find out about plants, practical solutions and vernacular building styles suitable for your particular climate.
Climate Change
Long term changes to climate are a natural pattern. However, over the last couple of centuries, changes to human activities have significantly increased greenhouse gas emissions along with a reduction in the natural systems, or sinks, that absorb them. As a result of anthropogenic (human) activity, average global temperature and extreme weather events are increasing at a rate much faster than would naturally occur. You can see the latest CO2 data here.
For many of you, working out how to respond to a changing climate may be part of your motivations to becoming a designer. Realistically, in order to thoroughly discuss the causes and impacts of climate change we’d need to create a whole extra course. So let’s start with Zone 0, and work outward, as always.
How does climate change affect YOU?
How does it influence your decisions?
Are you noticing changes in your local climate?
How is your community adapting?
and so on…
As ecological designers, we aim to live and design our lives to reduce atmospheric pollution and support climate stability. We aim to incorporate design strategies to reduce, mitigate and regenerate our harmful impact and to design for resilience against changes we can’t prevent.
There are many ways to creatively respond to change in your design project, and we’ll spiral back around to these discussions again and again. Here the focus is on designing in different conditions of temperature, humidity and exposure to the elements at small scales, so we can increase our resilience through diversity.
Just as historical data and current observations about the local climate are part of understanding your design site you also need to consider the future climate in your designs. At a simple level you can include diverse “edge” species from nearby climate zones to buffer against changing temperature and precipitation conditions.
The idea of a climate analogue is just as applicable for discussing future climate scenarios. Increasingly online tools like this are available. These take a particular location as input and return climate analogue locations under different climate scenarios.
Climate change is part of the reality within which we live. We can make the greatest impact in reduction, mitigation, regeneration and adaption within our own lives and design projects. Working with microclimates is one of the practical tools we use.
Ecology and Local Ecosystems
This section by Lucie Bardos
- Ecology is the branch of biology that deals with the relations of organisms to one another and to their physical surroundings. As eco-logical designers, our designs need to support, encourage, and enhance the relations of organisms to each other.
- Ecosystems describe the web or network of relations among organisms at different scales of organization. A local ecosystem is made up of groups of organisms (and the non-living environment), interacting together as a complex, self sustaining, natural system.
- Download our ecosystems glossary of terms.
Classifying Ecosystems
There are several scales at which we can define ecosystems, depending on how much detail we are looking for. Below are some of the most common ecosystem classifications.
Biogeographical realms or ecozones. These are the broadest description of ecosystems and are based on general distributions of terrestrial organisms. They are: Neoartic, Paleoartic, Oceanic, Neotropical, Afrotropical, Indo-Malay, Australasian, and Antarctic.
Biomes. Biomes are give us a little bit more detail, but are still high level classifications for ecosystems. They are large regions of the world with similar plants and animals that are adapted to the surrounding climate and other abiotic conditions.Biome classifications vary slightly between different groups of scientists, but essentially they allow us to identify regions that are ecologically similar, even though they may be located on separate continents, such as temperate forests and grasslands.
Here is an example of a global biome map:
Ecoregions.
Ecoregions are a more descriptive type of ecosystem classification. They are defined by their geography and contain distinct groupings of natural communities. Ecoregions are complex and they exist on varying scales. For example, in North America there are Level I, II, and III ecoregions. Level I contains 15 ecoregions, Level II contains 50, and Level III contains 182. Level III ecoregions contain names like: Hawaian Moist Forest, Western Great Lakes Forests, and Chiapas Montane Forests.
Here’s a Level III map of the ecoregions of Canada, USA and Mexico.
If you live in North America, can you identify which ecoregion you are a part of?
Bioregions.
Bioregions are a way of reinserting humans back into the ecosystem equation. They are defined partly through physical and environmental features, such as watershed boundaries and soil or terrain types. However, what is really interesting about bioregions they are also a “cultural phenomenon.” Bioregionalism includes culture, local populations and their histories and knowledge as defining characteristics of a region.
For example, we can look at the Cascadia bioregion, also known as the Pacific Northwest, which hugs the coast from California all the way to Alaska. You will notice that its boundaries do not line up neatly with biomes or ecoregions. It is partly defined by the fact that its Indigenous peoples fished salmon, used the waterways as trading networks, and traded extensively with the people of the interior continental plate.
As a fun optional activity, try this bioregional quiz
Types of Ecosystems
We can classify ecosystems as belonging to two main categories, terrestrial and aquatic. Terrestrial ecosystems may include communities such as tundra, forest, desert and grassland. Aquatic ecosystems may include freshwater communities such as ponds, lakes, and rivers, or salt water communities such as oceans and estuaries. Ecosystems also may have differing levels of human participation and can include farms, gardens, managed bodies of water etc.
It is very important to note that outside of bioregions, what is not captured in many textbook style infographics depicting the different “natural” and “manmade” ecosystems is that many so-called “natural” ecosystems have been heavily influenced by intensive pre-colonial human activity. This includes forests, grasslands, and jungles. The colonial practice of erasing or invisibilizing the cultural and ecological footprint of Indigenous communities can be seen in the ways that we classify and teach about ecosystems in educational institutions. One example of this is human influence on a “natural” ecosystem is the “terra preta” or “black earth” soils found in the Amazon rainforest. They are evidence of ancient soil building techniques of Indigenous Amazonian peoples.
Ecological Succession
Ecological succession is the process by which an ecosystem evolves over time. It is a process that we utilize in ecological designs to envision how the landscape and its associated plant and animal communities will change over time.
There are two main kinds of natural succession: primary and secondary.
Primary succession happens when we begin with bare rock, such as lava flows, whereas secondary succession takes place after an existing ecosystem or community is disturbed by an event, such as a fire or a clear cut.
There are a few main roles that species play in ecological succession.
- Pioneers: these are the “weedy” species. They are fast growing, short lived, and thrive in harsh climates. Many pioneer species have the unique ability to access hard to reach nutrients stored in the bedrock or deep underground. They pull up the nutrients and store them in their tissues. The nutrients then get released into the topsoil as the pioneers die. Pioneers are soil builders!
- Early and mid-successional species: there are often short lived perennials, such as herbs and shrubs, or fast growing, short lived trees that require medium quality soil. They begin to shade out and replace the pioneer species and the soil quality improves.
- Late successional species: these are the slow growing perennials, often large deciduous or coniferous trees, depending on the geography and climate. They require nutritious soil and can grow in the shade of the early and mid-successional species until they surpass them in size and shade them out. Their presence indicates a mature ecosystem.
A great way to get a first hand look at succession in action is to go for a walk in your neighborhood and look for disturbed sites such as road sides, construction sites, or forests where trees have fallen. Look at what is happening on the ground:
- Do you see weeds, shrubs, tree saplings, or bare soil?
- What if you visit the site a year later or a few years later?
- How has it changed?
- Would the changes have been different, if different species had been living there?
- In which ways?
Primary succession
Secondary succession
Trophic structure, food webs, and energy flow through ecosystems
This section by Tara Rae
Producers are photosynthesizing organisms.
They make their own food (i.e., sugars) from the sun’s energy. Green plants make their food by taking sunlight and using the energy to make sugar. The plant uses this sugar, also called glucose, to make many things such as wood, leaves, roots, and flowers.
A small group of producers are called Chemotrophs (as opposed to Autotrophs) and they utilize chemicals in the environment to create food. An example of this includes some sulfur-eating bacteria which use sulfur to make energy
Consumers (primary, secondary, & tertiary) need to eat their food to get energy.
Animals are consumers because they cannot make their own food. Primary consumers (herbivores) eat plants to get energy, while secondary consumers eat primary consumers to obtain energy. Tertiary consumers eat secondary consumers.
Decomposers break down organic matter into little pieces of energy (i.e., nutrients) for plants.
Fungi (including mushrooms) and bacteria are the major decomposers, but so are many invertebrates. Worms and isopods (i.e., rollie-pollies) are examples of invertebrates which break down small pieces of organic matter and release it as fecal matter or nutrients in the soil for plants to use again.
Photosynthesis and respiration.
During photosynthesis, organisms such as plants, algae, and certain bacteria harness energy from the sunlight and convert it into chemical energy. That energy is stored as food (i.e. sugars/carbohydrates) while releasing oxygen.
Conversely, during respiration, organisms (animals and microorganisms like bacteria) use carbohydrates (i.e. sugars) and breathe oxygen to obtain energy. They release water vapor and carbon dioxide as byproducts.
Carbon Cycle.
All living things are made of carbon. CO2 in the atmosphere and oceans is cycled relatively quickly. The carbon cycle is a biogeochemical process by which carbon is exchanged between reservoirs. Reservoirs can be biotic, such as animals and plants, or abiotic, such as compounds like limestone. CO2 is a greenhouse gas that traps heat in the atmosphere. Without it and other greenhouse gases (e.g. methane), the earth would freeze. However, too much carbon in the atmosphere (e.g. produced by burning fossil fuels) warms the earth at a faster rate. This is what we call global warming; over time, this is referred to as global climate change. By burning fossil fuels, people are changing the carbon cycle with far-reaching consequences.
Nitrogen cycle.
The nitrogen cycle is a biogeochemical cycle by which nitrogen is converted into multiple chemical forms as it circulates through the abiotic and biotic environment. The conversion of nitrogen is carried out through both biological and physical processes. Microorganisms, usually the bacterial nodules on nitrogen-fixing plants (e.g. legumes) convert atmospheric nitrogen (N2) into Nitrite (NO2-). Then, bacteria convert Nitrite (NO2-) to Nitrate (NO3-). Nitrate, Nitrate, and Ammonia (NH4) are the usable forms of Nitrogen for plants. Denitrification occurs when bacteria convert Nitrate (NO3-) back into atmospheric Nitrogen (N2).
Microclimates: the Edge is Where the Action is!
This section by Klaudia Van Gool
Climate will vary more locally through human structures, topography, altitude, vegetation and water masses. This is called microclimate. By observing and analyzing our microclimate, we can design strategies to modify it.
Let’s look at some of these factors in more detail.
Topography is the shape of the landscape and includes aspect and slope. Hills, mountains and valleys affect how wind moves through a landscape, as the wind moves around hills, speeds up near the top of hills, and funnels through valleys.
Aspect, the direction land faces, affects the amount of sunlight on a site. For example, a south facing site in the Northern Hemisphere will be a sunny site and can produce more biomass/vegetation.
It is an extremely useful skill to be able to identify the directions, so that appropriate design decisions are made to optimise the microclimates of a site. When the sun is shining in the Northern Hemisphere, the sun is due South at 12.00 (and due North in the Southern Hemisphere). A way to determine North at night is to identify one of the well known constellations, the Big Dipper, to find Polaris, which is also known as the North Star. A line from the two outermost stars in the bowl of the Big Dipper points to Polaris.
In the Southern hemisphere, the Southern Cross can be used to identify South.
Slope, the gradient or steepness in the land, will affect wind speed; this increases towards the top of a slope. Turbulence will be experienced just past the top of a slope. This is important information when situating wind turbines, as they work more efficiently without turbulence. Cold air will sink and move down the slope. Accordingly, the slope will impact thermal zones, and a cold sink may occur just above structures or vegetation lower down the slope or in slightly depressed areas. In colder areas this can create a frost pocket.
Altitude. Temperature decreases with higher altitudes. We also find higher wind speeds and more moisture, because of rain or other precipitation at higher altitudes.
Studying existing vegetation can give us clues to rainfall, wind strength and direction and soil fertility. A way to discover the prevailing wind in our local landscape is by observing trees.
This picture shows how the wind has shaped the trees, restricting growth on the side that the wind blows from, so that there’s more growth on the other side.
As well as trees being affected by wind, trees themselves can also affect the wind in the landscape and other microclimate factors.
For example, in temperate climates it is cooler and less windy in a forest while it’s hot outside of it, as trees provide shade and a more moist microclimate and act as a windbreak. At night it stays warmer in a forest compared to out in the open, as the trees create shade from the wind and trap warmth. This does depend on the season and vegetation/leaf cover.
On a larger scale, trees contribute to the creation of rain through evapotranspiration. See further reading for a couple of inspiring videos.
Ecotones.
These are the areas where two or more habitats overlap and are often home to unique microclimates. Because this overlap area has characteristics of both, more diversity is present in this area than in either of the edging habitat, including microclimate differences.
This picture shows the diversity of a wetland, an ecotone between river and land. As ecological designers we generally aim for high diversity, and therefore incorporate edges deliberately into our designs.
A classic practical example, working with microclimate, edges and the natural pattern of spirals is the herb spiral. This is a small mound with a spiral edging going all the way up.
In creating this shape, we create different microclimates and can therefore grow a wider variety of plants. We can grow dry-climate, sun loving plants at the top and on the sun side, and more shade and moisture loving plants lower down and on the shade side.
Structures.
Urban environments create warmer microclimates through the “heat island effect,” as concrete absorbs more heat than the surrounding countryside. In general it is warmer in the centre of a city.
The hard surface of buildings, roads and straight lines of streets also create a wind tunnel effect, where wind speeds up. Tall buildings can create wind turbulence. Buildings can create a rain shadow, so there is a drier and a wetter side.
Microclimate and niche
Microclimates are directly connected to ecological niches, where organisms occupy a space where they can thrive optimally.
Creating, or being aware of having, a variety of microclimates, means you can have a wide variety of niches for more diverse planting, keeping animals, and thus increasing yields.
Microclimate modifications.
We can make modifications to a microclimate to reduce and direct wind flow, as wind has a growth limiting effect on vegetation. On a windy site, planting windbreaks and shelterbelts is one of the earliest modifications needed. These create more sheltered areas and can direct the flow of air, including cold air coming downhill. Using plants to reduce wind is more effective than solid structures, which create more turbulence. In addition, we can choose species for multiple functions, which again creates more yields.
We can modify our local climate or microclimate by adding water storage, which can modify temperature fluctuations. On a larger scale, we can introduce lakes or ponds to modify heat and to add light reflection. On a smaller scale, adding water storage inside a greenhouse or polytunnel will help buffer extremes of temperature.
In hot climates, planting trees and adding vegetation gives a cooling effect. This is as a result of shade and evaporation, which creates cooling.
We can modify climate and microclimate through buildings, like adding a greenhouse. When we place a dwelling to the North of a greenhouse (in the Northern Hemisphere) we can make use of surplus heat and protect plants. We can paint walls white in darker, shadier areas to direct in more light and improve growth and ripening by reflecting light. Dark walls reduce frost risk by keeping warmer.We can use thermal mass like rocks or stone walls to absorb heat and plant more tender plants close up to it. We can also use the cooler temperature of the Earth, whilst it’s warmer at the surface, to create a root cellar for food storage into the Earth, without energy based refrigeration.
In cooler climates, you can create sun traps. These designs are sun-facing and wind-still, creating shelter from cold and destructive winds by capturing maximum sunlight all day. In the Victorian era in the UK, walled gardens were built on large estates to create microclimates for tender crops. Fruit trees were trained up against the walls in fan or espalier shapes.
Hot beds are created by placing small glass frames on top of piles of manure, which generated heat as they rotted down. This is a form of season extension. You will learn more about season extension in a later module.
Extra tips for finding microclimates:
- Visit the different microclimate sites with a thermometer and record the temperature at different times of the day.
- Visit the sites with a wind meter. If you can, borrow a wind meter or tie a ribbon to a stick to observe the differences in wind speed between different locations.
- Observe pets and small domestic animals: Where do they hide on hot days or windy days?
- Watch human behaviour in different microclimates, for example, where people wait for shops to open on cold days or on hot days.
Microclimate observation exercise
Collecting hard facts about climate is one aspect of understanding a design site, and making further observations on site helps to contextualize the site and map its microclimate. These experiential exercises are a great way to develop designer’s mind.
Sensory attunement exercise
Instead of watching this video in your house, have a listen to this sensory attunement meditation as you go for a slow walk around your (design) site and make observations.
After a while, you can start making some notations on a basic sketch map of your design area:
- Notice how microclimates work with both intentional and unintentional design.
- Note other microclimate factors: buildings/structures, landform, altitude, aspect, slope, larger vegetation; sketch these onto your map.
- Make a very basic notation of the microclimates with colours or symbols.
- Note areas that are driest, wetter, windiest, most wind-sheltered, where it might be warmest in the morning and evening, and anywhere that would be cool all day.
- What different needs and opportunities are associated with these microclimates?
Now watch this video:
Homework
This Module is Special
As we’ve been saying, the “Homework” sections at the end of our topical modules may be considered optional, and should be seen more as something to explore in the years to come, rather than to bang out in a hurry so you can get your certificate. ONLY the assignments in the 11 classes of the Design Studio are “mandatory” for your certificate.
That being said, the homework section of this module will be echoed in the Design Studio, so you may as well jump in and learn as much as you can about this topic now!
Tasks related to your design project “deliverables”:
- Compile climate data for your site: hardiness zone, average rainfall, frost dates, prevailing winds, etc.
- Map every edge zone and microclimate you can identify on your site. Indicate microclimates you would like to change or create.
- Create a comprehensive species list for your site and the surrounding ecosystem.
The questions and optional hands-on below will help you with these assignments…
Questions for Review
- Identify your local climate and hardiness zones. How will they affect your design?
- Are there any short term changes you have noticed in your local climate? What are your gut feelings about future climate conditions in your area?
- What are the common plants, animals, birds, insects, and other living species found in your local ecoregion? Which of them are living on your site? What roles do they play in the food & energy web?
- Identify local ecological pressures related to your local ecosystem (e.g. mining or development pressures) and how the ecosystem reacts (e.g. more weeds). Are there ways you could mitigate these, within your design, to support the regional ecosystem?
- Describe/draw the energy flow through your neighborhood. It could be nutrients, water, food, people. What are some of the integrated feedback loops?
- Ask yourself, how do you fit into it all?
Recommended Hands-On
- Visit a local woodland and observe the differences outside of and within a forest environment.
- Visit an urban environment and observe the wind tunnel effect in streets with high buildings, and how the wind direction changes with the direction of the streets.
- Identify and map the microclimates on your site.
- Seek information about your local ecosystems and use it to influence the decisions you make for your design.
- Find a few examples of the ecological principles at work in your local ecosystem. How can you mimic them? How can you enhance the flow and productivity of the tiny ecosystem that is your site/design project?
- Consider your own community’s social ecosystem. How diverse is it? Who are the producers, consumers, and decomposers in your social network or town?