Soil, being the foundation of life, is of great importance to human and nature
Every day as you lay your feet on the ground and walk the earth, have you ever wondered what lies beneath? Soil. This material exists on the outermost part of Earth’s crust, forming the surface of land and sometimes regarded as “skin of the earth”.
The uses of soil are endless.
Soil is an important natural body as it supports agriculture. Most of the food we consume can be traced back to soil because it is the original source of nutrients needed to grow and produce food. Soil also plays a crucial role in the water cycle. Not only does soil store and filter water, providing a clean supply of water, it too improves our resilience to floods and droughts, especially in the face of climate change. On top of that, soil is a habitat for a wide variety of organisms. It houses microscopic organisms to soil fauna of larger sizes – for example, earthworms, springtails, burrowing rodents, etc. Soil is undeniably an extremely valuable and vital ecosystem that delivers ecosystem services, enabling life on Earth, fundamental to our survival.
So what exactly is soil?
The Soil Science Society of America defines soil as the unconsolidated mineral or organic material present on the immediate surface of earth, serving as a natural medium for the growth of land plants. Others describe soil as layers of generally loose mineral and/or organic material that are affected by physical, chemical and biological processes at or near the planetary surface and usually hold liquids, gases, and biota (living things) and support plants.
Composing of a mixture of minerals, water, air, organic matter, and decaying remains of living things that once lived, the components of soil fall into two distinct categories: biotic and abiotic factors. The biotic factors encompass both the living and dead – for instance plants, insects and even soil microorganisms such as archaea, fungi, algae and more. The abiotic factors on the other hand represent non-living things which include minerals, water and air. Commonly found soil minerals such as nitrogen, phosphorus and potassium are amongst the essential nutrients needed for healthy plant growth followed by calcium, magnesium and sulphur. The combination of these factors ultimately determine the properties of soil – its texture, structure, porosity, chemistry and colour. But that’s a topic for another day.
Undoubtedly, soil builds and supports the foundation of a community, a nation, and basically any form of life. The giving nature of soil provides us and other forms of life with an abundance of resources.
Soil can also be described as a repository of memory, holding records of the past of our planet, our evolutionary history of how far we have come. It may also store secrets and possibilities that have yet to be discovered to a sustainable future.
Essentially, all life depends upon the soil… There can be no life without soil and no soil without life; they have evolved together.
Dr Charles E. Kellogg
So while you keep your feet on the ground, stay grounded and stop treating soil like dirt.
Soil organisms constitute more than 25% of discovered biodiversity on earth. However, much of them remain unexplored and receive little attention compared to aboveground organisms.
Though less visible, these organisms are responsible for various ecosystem functions such as:
supporting agro-ecosystems etc.
The ecological processes in soil are mainly driven by interactions between soil microorganisms and plants, especially their underground roots. The soil microbes (microscopic organism), mainly bacteria and fungi, break down dead organic matter e.g. fallen leaves and release minerals and carbon compounds into the soil. These nutrients will be reused by plants for development. Some microbes establish mutualistic relationships with plants. For example, the mycorrhizal fungi transport water and minerals to the plant, while they receive carbon in return.
The soil microbes also suppress plant diseases by competing with disease-causing organisms, colonising or consuming them.
Soil microorganisms are important in maintaining soil structure and retaining water.
The sugar-rich secretion of bacteria or threadlike filaments of fungi bind soil particles into small aggregates which are physically and chemically stable.
The microbes are eaten by larger soil organisms i.e. the protozoa and nematodes. These small animals are then eaten by their predators such as insects, centipedes, spiders and scorpions. This underground food web is connected to aboveground food web as soil-dwelling animals become the food source of animals that live on the ground such as birds, snakes and frogs.
Aside from organisms in the grazing food chain, there are animals thatfeed on dead plant materials. Unlike decomposer, these animals need to orally ingest the organic matter and digest it inside their bodies. Some examples of these detritus-feeders are woodlices, beetles and termites.
A pleasing fungus beetle feeds on fungus and decomposing matter.
Cave cricket lives in leaf litter.
Apart from that, the earthworms which feed on leaf litter and soil are known as ecosystem engineers as they produce nutrient-rich castings and create pores in soil. The castings are important for soil aggregate formation and plant growth, while the pores in soil facilitate water movement, increase water infiltration and alleviate flooding.
Like aquatic and terrestrial organisms, soil organisms are threatened by a series of environmental issues. The major threat that they face is habitat loss, which results from land conversion, pollution, climate change and invasive species. Agricultural activities such as “tillage” alter composition of bacterial communities and reduce diversity of soil fungi and larger animals. Construction of roads, buildings and street pavement damage the soil structure and destroy soil organism’s habitat.
Habitat degradation occurs when the soil is polluted. Pollutants such as heavy metal and excess nutrients change the soil environment chemically, usually in an abrupt and profuse manner. This makes the soil condition unfavourable for many existing soil microorganisms. As a result, only a few pollution-tolerant species survive and dominate the community. The overall microbial diversity and activity decrease.
The alteration of environmental parameters as a result of climate change also affects soil organisms. Increased concentration of atmospheric CO2 triggers responses of soil fungal communities. Such responses are reflected in the amount of living plants in the area. Quantity and frequency of rainfall and changes of temperature also impact underground animals such as insects. However, the impacts vary by taxon (unit used by scientists to classify organisms) and ecosystem as some are more resistant to environmental changes while some are more vulnerable.
The intrusion of invasive species such as exotic plants brings changes to the soil environment as well as underground microbial communities.
Their roots release a new combination of chemicals e.g. sugars and enzymes into the soil. The type and amount of chemicals are different from the ones released by original plant communities. This affects the activity and population size of microbial community at the rhizosphere i.e. portion of soil surrounding roots of living plant as its biological and chemical properties are influenced by the roots. The invasive plants also impact the soil organisms by interfering with nutrient cycling e.g. the legume plants, or changing the amount of litter and root inputs.
Conservation measures to support soil biodiversity include managing natural areas, restoring degraded ecosystems, adopting sustainable farming practices and adapting urban areas for both nature and people. Identifying undisturbed land and protecting it are important to sustain soil biodiversity as the habitat quality of soil organisms is maintained. Other than that, both artificial and natural revegetation of disturbed land help soil microbes and fauna to re-establish.
Sustainable farming practices are also important in conserving soil biodiversity. Reduced tillage, crop rotation, planting of cover crop and retention of litter are some useful measures to improve soil quality as well as support soil biodiversity. Allocating spaces for greenery and wildlife in urban planning, establishing green roofs and rain gardens, reduced soil compaction and using mulch as groundcover are some of the ways that encourage soil biodiversity in urban areas.
Alizabeth M. Bach, K. S. (2020). Soil Biodiversity Integrates Solutions for a Sustainable Future. Sustainability, 2662.
Resources produced by plants for animals come in many forms. Some animals require the presence of water for reproduction like frogs. Others like butterflies require shade to prevent overheating. Some require very specific structures like rotting wood, or crevices to complete their life cycle.
When it comes to planting, plants produce resources for animals in several ways:
Many plants produce food in the form of leaves for folivores (leaf eaters), seeds for grainivores (seed predators), fruits for frugivores (fruit eaters) or wood for xylophages (wood eaters). These in turn become food for other animals in the food chain. In tropical rain forests, figs and palms have more frequent fruiting cycles and are a staple of many frugivores diets. Dipterocarps and oaks, which make up the majority of trees in our lowland forest, fruit less frequently but produce large quantities of seeds every 2-12 years in a phenomenon known as “mast seeding”. Fallen leaves, logs and branches also provide food for invertebrate decomposers.
Many plants have chemical defences that make them poisonous to some animals (like tobacco and caffeine). However some animals have been able to overcome these and have adapted to solely feeding on a small variety of plants, these animals usually require the host plant to complete part of their life cycle. For example the tree Saraca thaipingensis is the host plant for the butterfly Drupadia ravindra. Planting larger varieties of plants usually leads to an increase in insect life due to a higher availability of host plants.
The majority of animals are not able to maintain their body temperature and must depend on their environment to heat up or cool down. Plants change the thermal environment by releasing water vapour into the air and reducing the amount of sunlight and heat below them.
4.Nesting space/nesting materials/shelter
Plants with complicated structures are often good places to hide for many smaller animals. Larger animals such as monkeys also use trees to rest at night to avoid predators. Plants with large root systems or branching growth are especially good for animal nests. Some frogs have adapted to laying their eggs in epiphytes or bamboo.
Many animals use plants as a space for attracting the opposite sex. Birds often require trees to make mating displays. Some flies also use leaves for performance space, while beetles often need rotting wood as a place to attract mates. In some cases the loss of certain plant species leads to the loss of animals that use them for mating, like mangrove fireflies and berembang trees (Sonneratia caseolaris).
As humans we view ourselves as nothing special. This thinking causes all sorts of problems for the wildlife around us, because humans are in fact quite extraordinary creatures, and when we design our spaces for extraordinary creatures we exclude the average animal.
If I was to describe the average animal species, it would be cold-blooded, it has a narrow diet, it is very small in size, likely it can fly and it would be negatively affected by artificial light.
Humans are fantastic at sweating and warming ourselves up. We have one of the best heat regulation systems in the natural world, and it is so good that we rarely think about it.
We can heat ourselves up when we are cold and sweat off any excess temperature. Many animals have to depend on their environment to be able to do so.
But this leads us to build cities that are designed for amounts of heat that humans can handle, but many other animals cannot. We also carelessly use materials like concrete and glass that reflect a lot of heat, creating areas that are bearably hot for humans but lethal to some animals.
We eat a lot of things. Our diets are very wide, and we take food from many different levels of the food chain. Compare that to the limitations that most animals face: predators usually have a small set of prey that they can hunt or some herbivores are limited to only single host plant.
When designing habitat, we should consider that many animals have a limited set of items that they can feed on. Many butterflies need host plants to survive, and without these plants you can’t have enough caterpillars to sustain a population of insect feeding birds.
Many birds are limited by the design of their beak, if there isn’t the right types of fruit or seed available they might not be able to survive in an environment.
We are very much in the upper limits of animal size. We usually compare ourselves to megafauna we see on National Geographic, but considering that the smallest animals are smaller than specks of dust and most animals are actually less than a few centimeters in length, we’re really big. And this is a problem when we think about habitats, we assume that animals need as much space as us. In many cases they can do with less.
Frogs can live in a system that consists of a few ponds or streams, millipedes can spend their entire lives in a single log and populations of butterflies can survive in small parks or patches of forest.
The modern human lives in a 2-dimensional world, we rarely need to move upwards or downwards unless we are changing the level that we are on. Therefore we rarely think about 3-dimensional space, especially space that can be reached through flight.
Most species of animals can fly. Most insects are able to fly at least at one point of their lives, birds are capable of flight, mammalian bats can fly, even reptiles and amphibians have evolved the ability to glide.
This means that they can move in ways that humans can’t. Roads with heavy traffic may be an obstacle to humans, but not a bird. The ledges of buildings and the rooftops of our cities are all fair game for animal habitat.
We can create light and it doesn’t have a seriously negative effect on us. This is not the case for many animals with strict activity periods.
Artificial light can extend the activity of birds, causing them to use up more energy or become more stressed. It can be downright lethal to many insects since it affects their navigation and causes them to fly about lights until the die of exhaustion or get eaten by predators.
Humans are a special class of our own. And when we consider the needs of animals we need to consider that animals are very different from us, so we need to design with their need in mind as well. When we do that, there is a surprising amount of space for us and our animal neighbours.
Most animals are what we would call “cold-blooded” (This is not a proper scientific term, it is more accurate to say they are exothermic and poikilothermic). Unlike humans, they can’t generate their own body temperature and depend on outside heat.
They are also less capable of dealing with higher temperatures, it can cause them to overheat. This means many of the hotter zones in our cities are barriers to their movement.
Our obsession with concrete, steel and glass, the modern designs of our cities don’t take into account the thermal environment. Combined with the tropical heat, our architecture creates an environment that is hostile to life.
Our cities are often too hot for invertebrates, except for hardy pest species. And when there are no other animals to control them, these pests can multiply out of control. But they often are not enough to sustain viable food chains.
Imagine a city where controlling the temperature is a goal, and biodiversity is one of the indicators of whether you can achieve that goal. Living things such as trees, rain gardens, green spaces and green walls can greatly help to dissipate heat.
Not only would it be healthier for all living things, but for humans as well.
Biodiversity is the variety of animals, plants and fungi in an area. It is also the variety of genes within each species.
Many don’t know that Malaysia is country with mega biodiversity, which means that compared to the rest of the world we have many times more diversity. For example in Malaysia we have 6000 species of moths, 2000 species of bees, 8000 species of ants and 200 species of dung beetles.
Of course in cities there are far fewer species. The study of urban biodiversity is about what can survive in our cities and the unique new ecosystems that emerge in them.
An example of urban biodiversity is the patches of pavement plants that grow next to our pathways, or the banyans that take over buildings as soon as they are abandoned. These become the foundation for food chains that allow pollinators or fruit eating birds to live in our cities.
In terms of genetic variety, a good local example is the different breeds of banana that we enjoy. Malaysia has a wide variety of wild and domesticated banana species, and these allow us to have a wide selection of pisang goreng as well as the genetic diversity to breed more resilient crops in the future.
There are practices that we can do to make our cities more friendly to wildlife, this website is a repository of information on how we can create cities that can serve more than just humans.
from Biodiversity Gardens Capacity Building Workshop with Dr Noraini Bahari
Dr Noraini Bahari is a member of MY Bee Savior. She was a landscape architect at USIM for six years and is currently a senior lecturer at UiTM, Perak.
MY Bee Savior Association is an NGO that was established in 2015 to create public awareness of the importance of bee sustainability. It also aims to strengthen the efforts to increase bee populations and to empower corporate commercialisation in the field of bee keeping. Bees are highly important for crop pollination. These bees include Apis mellifera (western honey bee), native to Europe, and Apis cerana (eastern honey bees) which can be found in our country. They are highly managed in hives for crop pollination.
Populations of these agricultural pollinators are declining worldwide. This phenomenon, known as Colony Collapse Disorder, occurs when the majority of worker bees disappear. It first came to the world’s attention with reports of western honey bees disappearance in North America in 2006. But most beekeepers in European countries (especially in Northern Ireland) experienced a similar phenomenon in 1998, where there was a reported decline of 50% in bee population.
Now, this phenomenon has become global and affects some Asian and African countries as well. This shows the great need to protect, conserve and preserve our bee populations. We have to start worrying now before it is too late.
The possible causes of Colony Collapse Disorder include climate change, non-native species presence, pesticides and genetically modified crops. Discontinuous supply of flora resources, disease and habitat fragmentation all play a role in the decline of bee populations.
Bees need us. How can we help them?
From the perspective of a landscape architect, one of the ways which can help restore bee populations and preserve their habitat is establishing bee gardens. Cities hold the key to saving bees because cities encompass urban green spaces (UGS), for example, green roofs, public gardens, community gardens, allotments, domestic gardens, etc. The ability of these places to support biodiversity has been recently acknowledged. There is now a call to effectively integrate these UGS in biodiversity planning and management to ensure their full inclusion in biodiversity conservation.
The urban garden is one of the UGS that we are concentrating on now. It is preferred by bees because of the wide range of fruits, vegetables, flowers that can be found in the garden. Many studies find that urban gardens often attract up to ten times more bees than the places we might consider bee havens such as nature reserves, parks, cemeteries and other public green spaces. This is because bees are unable to thrive when there are only trees or turves. Thus, we should try to plant a variety of flowering plants that are richer in pollen and nectar.
Bees provide flowers the vital service of pollination, help us to produce healthy crops and maintain thriving ecosystems, which in turn ensure our health. In simple words, bees are important for the overall health of the environment.
Here are some of the bees that can be found in our cities:
honey bees (lebah madu)
stingless bees (lebah kelulut)
solitary bees (lebah tunggal)
bumblebees (lebah dengung)
(among the four types of bee, the bumblebee is perhaps the most glamorous because of the movie Transformers)
Establishing bee gardens in the city
Bees are unique insects. They play a major role in plant pollination due to their absolute dependence on flowers as their source of food. Therefore, bees that live in the cities seek out green spaces like parks and gardens. These green spaces in urban areas provide a proper habitat to the bees, thus helping in the conservation of bees.
When designing a bee garden, the flowers have to be in large patches because these would allow bees to dine at one spot for a long period of time. Otherwise bees would expend too much energy flying from one location to another, leading to stress. In one spot, we ought to have more than two species of plants. Researchers suggest a minimum of ten species of plants to be planted in one spot.
When there is limited space, a vertical bee garden can be one solution. We can use walls or trellis as media to hang the plants. We can also make cool ponds for bees to take water, adding features like pebbles in the water so the bees have something to land on and do not drown.
Typology of green spaces for bee gardens
There are many types of green spaces in the city. When considered collectively as wider infrastructure, they can create extensive and powerful recreational, cultural or community spaces and improve environmental quality as well as provide diverse and species-rich habitats.
Urban squares attract urbanites to get together and socialise, why not extend this function to let bees to have fun as well? By planting a variety of trees and plants in the planter boxes, and establishing green roofs at the gazebos, we can make urban squares key sites for conserving bee populations.
Bioswale or rain garden can be turned into ‘Beeswale’ gardens. While managing the stormwater, we can also take care of urban bees.
Vertical walls have an amazing and dramatic appeal. These walls are popping up in major cities all over the world. A large vertical wall can be covered by hundreds of plant species which are good for bees.
Bee pop-up gardens can be established anywhere in the city, even at the roadside or in parks. They beautify the environment while providing foraging habitat for bees in the city. One of the pop-up gardens in Sweden comprises hexagonal structures which act as planting vessels that contain plants and water. These gardens can be incorporated into edible gardens as well.
Other places include rooftops, residential gardens and small individual gardens.
The landscape structure of bee gardens
To sum up, the basic elements for creating bee habitats are softscape, hardscape and water features.
Softscape refers to a composition of native plants with varieties of bee-preferred species. These plants should have flowers that are rich in pollen and nectar. It is good if the plants flower all year round. The plants also have to be intensely fragrant and have vivid colours. Some choices include Cosmos caudatus (ulam raja), Portulaca grandiflora, Angelonia spp, Antigonon leptopus (coral vine or air mata pengantin), Jasminum sambac (jasmine), Nelumbo nucifera (lotus).
Hardscapes or hard structures such as planter beds, boxes or vertical walls support the plants. These structures are useful when you have limited garden space. We can also construct bee houses or bee hotels for solitary bees to rest, lay eggs and raise their young. Although these bees do not produce honey, they are excellent pollinators.
from Biodiversity Gardens Capacity Building Workshop with Tan Kai Ren
Tan Kai Ren was the project officer of the Rimba Project in University of Malaya where he conducted a series of urban biodiversity conservation and education programmes. He also organised the Klang Valley City Nature Challenge in 2019, a citizen science project that focused on collecting biodiversity data in the urban area. A former YSEALI Academic Fellow for Natural Resource Management and Environmental Issues, he is now an environmental officer at Club Med Cherating.
Kai Ren discusses how we benefit from biodiversity and how we can introduce elements that promote urban biodiversity.
Importance of biodiversity
Biodiversity provides us with oxygen and food, a fact that many of us seldom appreciate as we do not see the link between nature & human. It helps increase productivity as diverse soil microbes are involved in nutrient cycles where they break down organic matter underground and keep plants healthy.
Biodiversity also contributes to our health. Many pharmaceutical products are made with raw materials that come from many different plants in the forest. It contributes to our economy as well: places with high biodiversity become recreational destinations and attractions for tourism.
Biodiversity contributes to pest control too as it regulates the number of pests by natural processes through prey and predator interaction.
The keys to high biodiversity in your garden
High number of plant species results in high diversity of features and micro-climates that promote different kinds of wildlife. For example, companion plants grown alongside desired garden plants distract insect pests. This helps targeted plants grow more successfully.
Selecting local plant species for your garden attracts local animals as they seek their preferred food.
There is an easy way to look at how local wildlife can improve our life quality. The plants and animals such as the mammals, insects and birds in our garden interact among one another, forming food webs that regulate the population number of each species, including pests.
Many people think that more plants will attract more mosquitoes. In fact, once a whole ecosystem is established, there will be fishes eating the mosquito larvae and dragonflies eating the mosquitoes. As a result, less mosquitoes are found in the place.
The roles of a garden as a habitat
As urbanisation takes place, land that was covered almost entirely by natural forest habitats is replaced by high-rise buildings, roads and houses that lead to habitat fragmentation. Some animals find it difficult to survive in such conditions, especially those that need large spaces, e.g. elephants, tigers and other large mammals. Animal populations end up being threatened, some may become locally extinct, even the so-called common or urban species.
To re-introduce wildlife into our city, we can start growing fruit trees and wildflowers in our garden, as these plants attract butterflies and birds. We can view gardens as a shared space for ourselves and the wildlife. When we establish a balanced ecosystem in our garden, our garden serves as a place for animals to rest, nest and feed. Perhaps it is not for the relatively large animals, but the garden is still friendly to smaller and more mobile animals that contribute to the food chain.
We can view gardens as a shared space for ourselves and the wildlife.
We can try to make our gardens a bit wilder so as to attract wildlife such as the monitor lizard, bats and the Asian tree toad. Sometimes, when biodiversity comes to us, we push it away for reasons like guano from bats, for example. However, we can still try to find a solution to overcome these problems.
During the Klang Valley City Nature Challenge, over 2000 species of plants and animals were documented in Kuala Lumpur despite its urban setting. Urban gardens play a large role in supporting wildlife. Therefore, anyone can contribute to wildlife conservation, even in the city, by just growing a single plant in his or her garden.
Elements to encourage biodiversity
Sunlight. The essential element that plants can’t live without but there should not be too much exposure.
Shade. Shade is especially important for certain plants such as moss, ferns and orchids.
Water. Both continuous supply and temporary puddles are important to wildlife. Water features will attract frogs that eat mosquitoes.
Hideouts. The small lizards and frogs need these dark spaces, whether they are natural or artificial.
Plants. Have more plants that attract pollinators such as bees, butterflies as well as birds. The selection of plants depends on our expectations and objectives. Arrange plants in multiple layers to create spaces for shade-loving species. It is important to know the growing requirements of the plants. Choose plants that flower and fruit all year round. These plants are best for wildlife.
Decaying materials. Compost, logs, mulch that consists of dry leaves or wood chips increase biodiversity underground and keep plants healthy.
Feeding station. Provide grains for birds.
Ideas for a wildlife garden
Build an insect hotel by piling branches or rocks to create a moist and dark space for the insects.
Mulch plants to attract beneficial insects and earthworms that help release nutrients back into the soil. This will also attract more birds e.g. the wild junglefowl.
Create a small pond using plastic bottles or trays. Insert fish to inhibit breeding of mosquitoes. Small ponds help to increase biodiversity despite their size. It is also a good place for dragonflies to lay eggs.
Start composting. We produce food waste every day. The fruit peels or roots of vegetables can be turned into compost that help gardens grow.
Limit the use of insecticides as the toxins will cause long-lasting effects on non-target insects. Try alternative methods e.g. hand removal of the pest insects.
Plant fruit trees as most of them are perennial. Besides, they bear edible fruits for humans and animals.
Knowing your limits
Knowing the right microclimate is especially important for plants such as orchids and leafy vegetables. Also, make sure there are enough spaces for the plants to grow. The intensity of sunlight is a decisive factor for plant growth. We also need to have the suitable soil type to produce healthy plants that support wildlife.
Most importantly, make sure you have enough time to manage your own garden. More is not always better as nature can be messy sometimes. It is always about balance. Avoid dominance in terms of plants as well as animals.