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Analogue forestry: Addressing biodiversity and food security

17 Jul 2022

 By Sarah Hannan Picking up from last week’s food security topic, we move on to forests and how they provide nourishment, not only in terms of fulfilling our dietary requirements, but also improving the nourishment of multiple living organisms, whilst refining air quality and soil quality and providing the environment to protect freshwater springs that are drying up due to unplanned development. Entering the closest thicket to source the much-needed firewood, leafy greens, fruits, and even medicinal herbs is still practised in the less-urbanised townships in Sri Lanka. However, if one is in an urbanised environment, all the above will need to be sourced from the closest boutique or supermarket. Today many households have gardens filled with ornamental plants. Those that have fruits and vegetables growing face the problem of pests, with monkeys feeding on the produce and destroying plants in the vicinity. Some have therefore opted to chop off fruit-bearing trees. However, Sri Lanka started to see a change in how home gardens were landscaped after the pandemic-related curfews, with people growing vegetables, herbs, and leafy greens in their gardens. Today, with prices soaring daily, many who resorted to growing their own food two years ago are now able to save money that otherwise would be spent on purchasing vegetables and spices, including turmeric, ginger, green chillies, and tomatoes, to name a few. What is an analogue forest? However, for those who own a considerable amount of land expanse, the ideal solution to follow would be trying their hand at analogue forestry. The Sunday Morning recently spoke to EarthRestoration Chairman Dr. Ranil Senanayake on the benefits we could reap by establishing such an ecosystem. He explained: “An analogue forest can provide nutrients throughout the year as different crops come into production at different times. It also helps with sustaining human health, because it contains many medicinal species in addition to food and commercial species. As an analogue forest contains many layers of vegetation, it gives a much higher output of oxygen and clean water and soil is improved through the planting of species designed to create a deep soil ecosystem.” Dr. Senanayake’s quest to establish or rather design an analogue forest began following his acquisition of a 17-acre plot of land in Mirahawatte, Bandarawela nearly four decades ago. “Part of the land I took over was a degraded tea estate; the other part was coarse grassland. The initial challenge was how to control the grassland fires and the lack of shade in the area. The next was to build carbon and nutrients in the soil,” he explained. Even today one can observe that the soil is tightly packed in the area and turning it into an environment where plants would thrive was a challenge in itself. According to Dr. Senanayake, the soil was of poor quality due to erosion and long-term application of chemical fertiliser. “The challenge was to grow the soil while arresting the erosive processes. The first steps were to establish shade and protection from erosive rainfall, so I used pioneer species like Trema, Erythrina, and Inga, to begin creating shade, shelter, and soil growth. It took about three years for me to get control of the erosive forces at work on the land,” he added. Essentially, when the analogue forest was taking shape in Mirahawatte, Dr. Senanayake was turning what was a monoculture farm, which mainly fostered a tea plantation, into a forest filled with native endemic species and exotic species, which started to improve the biodiversity of the area. Forty years later, he has introduced 12-14 species of alternative foods to Sri Lanka that grow well in tandem with endemic species. “If you consider introducing the knowledge to use already-present exotics as portrayed in my book ‘Exotic Medicinal Plants of Sri Lanka,’ it goes up to 50 or more. The forest has also attracted many creatures and is providing enough food for monkeys, giant squirrels, porcupines, and wild boar as well,” Dr. Senanayake noted. Natural deterrents for pest control The analogue forest maintained at Mirahawatte is free of chemical pesticides which raised the question of how Dr. Senanayake’s team is able to mitigate any pest attacks. “The biggest pest problems we face today are the large populations of monkeys, giant squirrels, porcupines, and wild boar to name a few. They have prospered in the forest we created and now become pests. As we do not kill any of the creatures due to ‘ahimsa’ reasons, we face the same problem faced by all rural folk today – partly due to the growing populations of pests and also because there is no control extended by the authorities whose mandate is to manage wildlife.” He said that there were minor problems with insect attacks at the start, but they were controlled by using botanical sprays and planting keystone species that provide food and shelter as biocontrol agents as the planting attained size. Monoculture farming to analogue forests The Sunday Morning spoke to Rainforest Protectors of Sri Lanka Convenor Jayantha Wijesinghe who is currently involved in reforestation efforts and is carrying out an awareness session on the dangers of monoculture farming to the environment and the surrounding forest reserves. Sharing his views on how analogue forestry could benefit the environment in turning monoculture farming into gradual analogue forests, he stated: “The initiatives will take a long time. Yet, if we could adapt the methodology of implementing analogue forests instead of monoculture farming, especially in the hillsides, that would not only benefit the people but also improve the quality of the soil and biodiversity, attract pollinators back to the area, and become commercially viable as well.” Wijesinghe further noted that in their efforts to acquire land parcels bordering buffer zones of forest reserves, they were also looking at establishing analogue forests to improve the top canopy and the underbrush. Initiatives are currently underway to protect the buffer zone of Sinharaja and the organisation is looking to purchase farmland plots that are used for monoculture farming and convert them to analogue forests or start with multi-culture farming. Improving air quality within confined spaces Research conducted by NASA has found that aloe vera has the ability to remove 90% of the formaldehyde from a chamber, Dracena marginata reduced benzene concentrations by 80% and spathiphyllum reduced trichloroethylene by 50%. The pollutants were ‘sequestered’ or tied up in the plant tissue and then acted upon by the various bacteria associated with its leaves and roots to break the toxins into harmless compounds. Subsequent research has shown that one or two plants per 8-10 square metres are sufficient in normal situations, although severe pollution will require ventilation and other physical measures in addition. When choosing plants to clean and maintain a healthy and safe breathing environment, it should be noted that one species of the plant alone cannot handle the diversity of toxins found in the household environment. Therefore, a wide variety of plants, each suited to removing a different class of chemicals, should be used. Consider the three most prevalent indoor pollutants as examples: formaldehyde, benzene and trichloroethylene. Formaldehyde is produced by plywood, carpeting, clothes, paper goods, foam insulation, and household cleaners. It produces headaches, eye and upper respiratory tract irritation, and asthma and can lead to throat cancer. This chemical is controlled by species of philodendron, aloe, scindapsus, and sansevieria. Benzene is produced by tobacco smoke, plastics, synthetic fibres, detergents, petrol, inks, oils, and moulded rubber products. It produces skin irritations, eye irritation, and loss of appetite, headaches, drowsiness, leukaemia, and other blood diseases. This chemical is controlled by species of gerbera, spathiphyllum, dracaena, and chrysanthemum. Inks, varnishes, paints, dry cleaning products, lacquers, and adhesives produce trichloroethylene. This chemical is found to increase the risk of cancer in the liver. This chemical is controlled by species of chrysanthemum, spathiphyllum, and bromeliads. Thus, the inclusion of living plants into the household and office environment would seem to be an essential need for indoor living. The increase in air-conditioning, which circulates toxic air without removing these chemicals, only adds to the risk. Therefore, indoor plants provide us with a widely and easily available weapon against some of the serious health risks associated with modern living. (Source: ‘Using Household Plants That Help Reduce Health Risks of Modern Living’ by Dr. Ranil Senanayake) Principles of analogue forestry Designing an analogue forest comprises four stages; baseline, design, management, and individual and collective expression. So before taking up the challenge to grow an analogue forest one must follow the steps given below: Baseline stage: 1) Observe and record: Where am I? In what type of forest? What species are present? 2) Understand and evaluate: Learn about the area, from both scientific and traditional standpoints. 3) Know your land: Examine the landscape features, water systems, soil, and ecosystems, terrestrial and aquatic. Design stage: 4) Map out flow and reservoir systems: Graphically represent the flows of water, sun, and wind. 5) Identify levels of yield: Identify the capacity of the land. How much could you harvest in each area? Management stage: 6) Be guided by landscape needs: Knowing your land and its surroundings is important for making a design. 7) Follow ecological succession: Imitate and accelerate the phases of the natural evolution of a forest from a pasture, or thicket, to a forest. 8) Utilise ecological processes: Designs can benefit from interactions occurring between elements of the ecosystem. 9) Value biodiversity: Increasing biodiversity of species will increase ecosystem function and provide valuable services and forest garden products. 10) Respect maturity: Mature forests are some of the most productive ecosystems and are the goal of analogue forestry. 11) Reduce the ratio of external energy in production: Minimise the use of fossil fuels. Encourage the recycling of nutrients and the use of natural fertilisers. How can we maintain a closed cycle within the plot? Individual and collective expression stage: 12) Respond creatively: Prepare yourself for the unexpected and be conscious that there are multiple pathways to success. (Source: ‘Field Guide to Analogue Forestry’ published by International Analog Forestry Network)  


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