We hear much about the hunter gathers of the savannahs and the plains. We hear less about the forest cultures who lived deep within a complex mix of old growth trees, shrubs, and groundcovers . Generally our agriculture has come from the grass-based plains. It relies heavily on cultivated grasses, or grains, and animals who graze on grasses. When I was in my early twenties and an intern at the Land Institute in Salina, Kansas, I was drawn to horticultural societies and agroforestry. At the Land Institute, we were envisioning a food system modeled after the diverse mix of perennial grasses and flowering plants living together in the prairie. This agriculture would be a perennial polyculture with its roots deep into the rich prairie soil undisturbed by tillage and the herbicides, pesticides, and fertilizers humans created to subsidize our tillage, disturbance-based agriculture. I kept wanting to talk about fruit and nut trees and the exciting diversity of small meadows at the forest edge. In exasperation one day, Wes Jackson, cofounder of the Land Institute, told me that when people get serious about agriculture, they plant grains.
He was right, especially in a world with burgeoning population growth. So, for the next 25 years I studied, researched, and taught horticulture/agriculture and produced organic vegetables and fruits on my farm in Montana, with as little tillage as possible. I added legume living mulches in between my straight rows of vegetables, fruit bushes, and fruit trees. I called my reduced tillage, increased diversity system agricultural ecology. But in 2011 I was humbled by a true agricultural ecology system. I discovered my first productive forest garden in Panama, created by a remarkable man who grew up in Argentina and gardened/farmed for many years in Hawaii. Forest gardening in the humid tropics is not for everyone. In fact, Bruce was the only one left of the group who originally started the Caribbean island coast farm, or forest garden. The partners returned to north America and are living on a grain based diet.
When we arrived on the island, we walked from the small town where the water taxi left us through neighboring land holdings to reach the forest garden. In Panama and Costa Rica we had already seen a lot of deforested jungle planted to plantains, banana monocultures, and pasture for heat-tolerant Brahma cattle. We saw more of this on the way to the forest garden.
When I walked through the gate and into the 60 acres of jungle that is this forest garden, I could feel, hear, and smell the change, the teemingness of life, the biodiversity.
The land had been in cattle production and cleared for pasture until 2003. Then Bruce started his process of planting an edible, mixed forest. His methods are based on ecological succession and the concept that there is never climax, or stasis in a plant community, it is always changing, modifying, and adjusting. Plant communities are a dynamic process and farming is a dynamic managing of interrelationships. Bruce started with fast-growing, competitive, (some might even say) weedy, pioneer species. His goal is to have canopy closure, soil coverage, in two years. This is key because exposed soil in the tropics quickly degrades as it is pounded by rain and heat. Plant material decomposes very fast and does not remain in the soil to form the skeletal framework required to feed soil microorganisms and plant roots. Another vital reason to cover the soil as soon as possible is to provide the shade needed for natural tree germination in a functioning forest. The regular shedding of leaves maintains soil fertility and feeds the soil food web, the co-mingling soil microorganisms who break down plant residues and release nutrients into the soil in a form that can be taken up by plant roots. Never chop a broadleaf plant or fern; it is the necessary understory for tree germination, Bruce cautioned. He has to keep a constant eye on his local employees hired to help maintain the dynamic process of managing forest garden interrelationships.
Our human tendency is to chop down excessive plant growth, clear away brush, control the wildness, make nature neat. If we do too much, however, we inherit the jobs of the organisms we get rid of and are forced to make and add fertilizer, apply fungicides to control disease, and insecticides to kill insects. Scientific research shows that the spatial, or structural, diversity in a functioning forest, what we call the "uneven texture" in a wild forest, enhances bird and insect population diversity and balances insect pest populations and outbreaks. In other words, the shape of a forest, from top to bottom, helps it maintain its own insect resistance.
Managing the interrelationships in this life-affirming forest garden in Panama means that when the trees have germinated and are growing, humans carefully release them into the sun. Maintenance consists of cleaning out vines and creating an opening of sunlight space by cutting down the fast-growing pioneer species. These fast-growing, early canopy closers can be used for lumber and building. It is all about timing of release into the sunlight.
Bruce walks through his forest garden and pinches off branches rather than pruning with a chainsaw. The pinched off green material ends up on the forest floor beneath the tree ready for the soil food web to cycle parts of it back to tree roots. From leaves to leaves, from roots to roots is a good description of what is happening here. I walked through the wild intermingling of this forest garden, being surprised by pendulous fruits hanging everywhere, including shiny, green key limes growing on small trees in a grove that Bruce said had become naturalized, already reseeding themselves. I thought of something a beginning gardener told me once as she showed me her rather chaotic mix of vegetables and flowers. She said, I think plants like to snuggle. At the time, I thought it was a cute sentiment without scientific merit. Now I am not so sure.
That is not to say that science is uninvolved in Bruces forest garden. There is careful selection of tree species in this interweaving of fruit, leaves, branches, and roots. Bruce chooses species with different growth forms, plants that have evolved to find and use light, space, and soil resources differently. Bruce designs his plantings alternating with crown-bearing and stem- bearing types of species. Some species bear their flowers and fruits at the top, in the spreading crown of branches pushed into the sunlight above shady interlacing forest braches. Others produce flowers and fruit along the stem and lower branches in relative shade, like cacoa. Again, it is all about managing the light resource. Sunny, open-loving species like mango and citrus are mixed with shade tolerant species like nutmeg. In order to mimic the closed fertility cycle of a forest, trees are mulched with fallen leaves and twigs regularly. No fertilizer inputs are brought in from outside the 60 acres. Mulching is the main fertilization. Lots of woody biomass and decomposing leaves are added.
Bruce has created an intricate system of water catchment ponds that fill with aquatic plant growth. He periodically removes and composts this pond vegetation. Then he uses the finished compost for new plantings, especially in the more cleared out garden areas where he grows sun-loving vegetables such as taro, a root crop with more calcium than cows milk.
I asked Bruce about protecting newly planted trees in the forest from animal and insect grazers. He did admit to some problems with leaf- cutter ants, who can defoliate even large, established plants overnight in the tropics. Newly planted nursery trees are sometimes protected from leaf cutter ants with rotenone-pyrethrum spread on their leaves. Once the trees attain several feet in growth, they are on their own.
I visited another reforestation project on the Pacific side of Panama. It is owned by a couple with years of experience doing development work in Africa . They had been planting their previously cattle-grazed 20 acres into a forest garden for about 7 years. The contrast with their neighbors acreages was remarkable. Theirs was a green island of diversity amidst a green desert of short, grazed grass. However, the planting had not become a functioning forest. More birds visited their land, but it was not teeming with life as was Bruces forest garden. One of the things they had to contend with was lack of connectivity to jungle nearby. There were no corridors of wild plants to provide seed sources, shade, and that non-scientific cuddliness of a healthy, intertwined jungle. It had all been cleared around them and there were competitive, sunlight loving grasses refusing to be shaded out. One of their management techniques also made a difference I think. The growth in their forest garden was not so lush due in part to their organic residue choice. Instead of mulching with forest litter consisting of a diverse mixture of decomposing leaves and twigs, they had brought in a fertilizer monoculture of rice hulls from nearby rice field production. When they planted a tree, they added rice hulls to the soil and mulched the surface with rice hulls. This was good for loosening cattle compacted soil and covering the soil surface, but it was not a good fertilizer and soil food web feeder choice. The rice hulls lacked the plant nutrient diversity of mixed forest leaves and twigs. I think the rice hulls had a greater carbon to nitrogen and carbon to phosphorus ratio than the forest leaf/twig mulch. This could inhibit root growth in the short run. I experienced this high carbon material growth inhibition myself while creating a new forest garden in British Columbia in 2009 and 2010. We disturbed a secondary growth forest full of alder, salal, evergreen huckleberry, and weedy blackberry vine. In fact, we ransacked the area and compacted the soil with an excavator. In the process, we added lots and lots of high carbon woody plant material (like tree trunks and large branches) as well as some green leaves and small branches. The first year the garden grew slowly and weakly. It was hard to dig in the soil to plant. The fluffy texture of an undisturbed forest floor, complete with a soil full of open spaces for air and water to move freely was lacking. Newly planted raspberry bushes had yellow leaves and other perennials were stunted. Potatoes and carrots developed small roots and yielded lightly. Annual plants growing in the same soil , but amended with seaweed produced a good amount of edible foliage and fruits. Nutrients were tied up as the high carbon woody material broke down (releasing nutrients and creating air pockets in the process). The soil food web was rebuilding after disturbance. We learned our lesson about disturbing the forest to plant a garden even before we experienced the forest garden in Panama. In time the high carbon materials will break down, the soil texture will loosen up, the soil food web will rebuild, and plants will grow with vigor. But why disturb so drastically in the first place?
The list of species in Bruces forest garden is daunting, more than 500 species. Here is a partial species list and descriptions. Edible fruiting and tasty, subacid mangosteen (Garcinia magnifolia and G. mangostana) are native to Central America, Noni (Morinda citrifolia) is native to southeast Asia and its fruits are used by some for treatment of breast cancer. Guaba,or ice cream bean, (Inge eduli) is a south American native, fast-growing legume which produces pods with edible white pulp in between the large seeds. Huge 5 to 50 pound jakfruits (Artocarpus heterophyllus) are native to south east and southern Asia; they have sweet, delicious, yellow, soft flesh and are loved by birds who have an uncanny ability to know just the moment fruits are ripe.
Noni fruit and noni flower amongst huge leaves. A large jakfruit in a not atypical jungle rain shower.
Achiote, or rambutan, (Bixa orellana) has red and golden spiny fruits used for oil, food flavoring, food coloring, and as a great source of antioxidants.
Guarabana (Annona muricata) with juicy, slightly acidic fruits and Posh-te (Annona scheroderma) which produce fruits that taste like a blend of banana and pineapple and are both native to Central America and are cousins of my favorite tropical fruit (in the Annonaceae or custard apple family), Rollinia deliciosa, or Biriba. Some folks I met in Panama called biriba custard fruit which seems a great name to me since it has creamy, white, sweet flesh and large brown seeds. The outside of the fruit is green and turns pale to brown when ripe; it has knobby skin. I could eat a lot of this fruit, and did while visiting Panama and Costa Rica.
Other fruit- producing trees are Abiu (Pouteria caimito) a native of the Amazonian part of South America with juicy, yellow fruit that has a leathery texture, and mamey sapote (Pouteria sapota) which are football sized fruits that are sweet and moist and taste like pumpkin pie filling, without the spices. Bazilian cherry (Eugenia brasiliensis) looks and tastes like Bing cherries and is considered an endangered species. Mandrona redea is a mangosteen cousin. Blackberry jam fruit (Randia Formosa) is a central and south American native with small 1 inch by 1 inch fruits filled with dark, seedy insides that really taste like blackberry jam.
Starfruit (Averrhoa carambola), a native of the Phillippines is juicy, sweet, and an amazingly prolific producer of fruits.
Eggfruit (Pouteria campechiana) is a native of Central and South America with sweet, orange-yellow fruits with a texture like cooked egg yokes. Cacao (Theobroma species) produces seeds that can be processed into chocolate, but the soft, white, spongy pulp around those seeds is sweet and delicious as soon as you open a ripe fruit, without waiting for the long process that leads to chocolate. When I was visiting in the Ecuador Amazon, every time I found and opened a ripe cacao fruit, my hiking partner (an orphaned woolly monkey) begged mercilessly for the tasty, white pulp. There are many species of cacoa, most wild ones very different from those grown on cultivated cacoa farms, which tend to all be a single cultivar. Tauga palm (Phytelephas species) is used for food in its native south central and South America and also as a source of vegetable ivory to replace elephant ivory. Peach palm (Bactris gasipaes) produces edible nuts which are used for oil and jellies and eaten raw by humans and birds, especially macaws, parrots, and parakeets. Other native palms produce nuts and heart of palm which monkeys also love. Edible flowering hibiscus are beautiful and attract a multitude of hummingbird species. There are also the more well known tropical fruits, such as coconut (native to Southeast Asia and possibly South America), citrus (native to Southeast Asia), and banana. Banana grows wild all over central and South America, but it is native to Southeast Asia. There are several species and many banana cultivars in all shades of colors, including red. Sweet and juicy mangos are more common place to North Americans. Mango is a native of India. Some tree and shrub and vine species are grown for their edible leaves, such as Katuk (Sauropus androgynus), another plant that originated in India. It produces a tropical salad green; its young shoots can be eaten like asparagus. Garlic vine (Cydista aequinoctialis) has leaves that smell and taste like garlic. Papaya is native to and naturalizes all over central and south America. Passion flower vines (Passiflora species) produces edible flowers and fruits. Finally there are species grown for beauty and aroma such as Lablab purpureus with delicate cream, yellow flowers with such a sweet, heady scent, I tucked one into my shirt and wore it all day on a long hike in place of a shower.
Forest gardening makes ecological sense. Thirty percent of the earths surface is covered in temperate forest. Where people cut down forests for wood and to clear land for grain and livestock agriculture, there is often erosion, soil loss, soil degradation, and certainly an enormous decrease in plant , animal, amphibian, microbe, and insect biodiversity. People in North America and Europe are designing forest gardens based on more northerly tree fruits and forest plants, such as cherries, apricots, wild and cultivated varieties of plums, pears, apples, mulberries, persimmons, walnuts, pecans, and chestnuts. Envision this: small and large fruiting shrubs, such as raspberries, blueberries, wild and cultivated varieties of currants, elderberries, figs, and hazelnuts intermingle within the gaps in a canopy of fruit and nut trees. Native wildflowers, wild edible greens (such as nettles), herbs, edible mushrooms, and perennial vegetables, such as Jerusalem artichokes cover and shade the soil. Vines climb on trees and shrubs with fruits of hardy kiwis, grapes, and passionflower hanging beneath the foliage. It is a 3-story effect rather than an agriculture all on one plane, such as a grain or tomato field.
Masanobu Fukuoka, the premier natural gardener, once said, "The ultimate goal of farming is not the growing of crops, but the cultivation and perfection of human beings." How we garden reflects who we are. Those of us who live in forest ecosystems spend a lot of energy plowing, mowing, cutting, weeding, and spraying to keep the forest from entering our gardens and farms. Gardening along with the forest, rather than fighting it back seems a kinder approach. One of the things humans are least apt to change is their diet. As I write this there is unrest in the world blamed partially on a scarcity of the food to which we have addicted ourselves, grain. Corn, wheat, and rice are expensive and hard to come by in some parts of the world now. Perhaps it is time to cultivate and perfect new ways of thinking, seeing, and eating. They are intertwined, just like a healthy forest.
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