The enormous and unrealized potential for diversified annual and perennial food cropping systems to provide for both food and wood resources cannot be over emphasized. Proof of the productive potential of such forest farming systems exists in almost every traditional culture around the world.
Examples of products from such systems include, but are not limited to: honey, craft materials, fruits, nuts, and berries, fuelwood, fenceposts, high-value timber, medicinal and culinary herbs, mushrooms, and saps, oils, and syrups. J. Russell Smith recognized the short-sightedness of the wholesale conversion of diverse forests into annual row-crop agriculture and in the 1920's began lobbying for a return to tree crops as a form of perennial, and therefore sustainable, agriculture.
As I've previously mentioned, an important element of ecological design is recognizing when we are in the historical context of the landscape. Understanding the history and process of human settlement in a given area gives us clues as to how our ancestors lived within their means. Most contemporary large-scale farms have evolved from smaller homesteads that supported families who necessarily led a more self-sufficient lifestyle due to their remoteness. Scattered in amongst the buildings of these farms can still be found the remains of antiquated orchards, which tell of the economy of past generations. It is not uncommon to find groupings of English walnuts, Bartlett pears, Gravenstein apples, Green gage plums, and hazelnuts. Old rosehips, raspberries, and day lilies are also frequently found competing with the grass. These old orchards provided a staple source of food for our ancestors and by canning, drying or otherwise storing the annual harvests they were able to provide sustenance for themselves through the winter. Perhaps the greatest benefit of tree crops was that they required little maintenance compared to the heavy labor necessary to produce annual field crops.
At the WTF we are honoring the work, good stewardship and wisdom of previous generations by reviving and learning to care for the legacy of old fruit trees that continue to occupy this landscape. To date we have identified such classic fruits as transparent apples, bartlett pears, and Italian purple plums. Our work has not ended with the restoring of these trees to production, however, for the space they occupy has the capacity to be exponentially more productive. Rather, we are currently working to develop an ecosystem surrounding these trees that meets their needs while at the same time providing a greater diversity of products to ourselves. Our rationale for adding complexity to the existing simple arrangements of fruit trees lies in the architecture of the forest.
Take a walk through any intact forest and you will notice a diversity of plants occupying many different layers in the forest's structure. These layers include canopy species, low-trees, shrubs, and herbaceous layer, groundcovers, vines, and tuberous plants. The forest stacks these layers so that space is economized and overall functionality and yield are maximized.
Every single plant, be it an alder tree or a red-flowering currant, interacts with many other elements of the forest. Birds are attracted to berries, dropped leaves provide a nutrient-rich mulch to nearby plants, shade provides suitable nursery conditions for young seedlings, and wind is buffered by plants along the forest's edge.
This series of mutually supporting interactions between multiple elements is called a guild. The concept of the guild can be directly applied to our work with orchards. By emulating the layered architecture of the forest we can construct a similarly multi-functional ecosystem within our orchards.
Plants can be chosen to attract beneficial insects, fix nitrogen, attract birds, deter browsing animals, provide mulch via leaf litter, uptake and release nutrients from the subsoil, or provide a moist microclimate beneath a shady canopy. The same plants may provide edible berries, medicinal and culinary herbs, mushrooms, edible tubers, cut flowers, and other usable products.
Consider the nut and fruit tree guild modeled in illustration X. This arrangement emulates the architecture of a forest ecosystem in that each plant is positioned in a specific ecological niche where it will provide the most benefit to the constructed guild. The nut and fruit trees serve as the canopy species providing shade and abundant leaf mulch in the fall to the plants below them. Raspberries in a dense hedge occupy the southwest edge of the guild as they can tolerate the hot afternoon sun while protecting the understory plants behind them from its desiccating effects. Currants, preferring a more moderate microclimate than the raspberries, find protection from the afternoon sun along the eastern edge of the guild and, along with the other berries, attract a wide range of birds thus introducing an important fertility element into the system. Understory herbs such as mints, nasturtiums, dill, elecampane, and borage manage insect populations by either attracting beneficials or repelling pests while simultaneously yielding both medicinal and culinary products. Nutrients are produced and recycled within this understory by another compliment of herbs including comfrey, vetch, red clover, borage, Italian dandelion, and burdock, many of which double as medicinals. Mushrooms inoculated into a woodchip mulch or into small diameter logs thinned from the food forest and located in the shade of the understory yield a premium product in their second year.
One approach we have taken to designing food agroforestry systems has been to select a primary species, say a variety of nut tree, and build the guild, or supporting ecosystem, around that species. In some cases there have been two primary species (i.e. nut trees & goats) which resultantly increases the diversity of supporting species and therefore the interactions between those species. Illustration X depicts the arrangement of a Chinese Chestnut guild that has also been designed to extend the forage season for goats, pigs, and chickens. In order to better understand the multi-functional nature of a constructed guild I have listed below several members from the Chinese Chestnut guild and have given a description of their functions and yields.
Chestnut (Castanea spp.): Chestnuts contain approximately 5% oil and 7% protein, along with a rich supply of carbohydrates, giving them a food value roughly equivalent to potatoes. Chestnuts can be easily dried and ground into flour for use in baking. As a forage tree the nuts are found quite delectable to hogs and, with the capacity to produce several hundred pounds of nuts annually, are capable of fattening swine in the Fall prior to butchering. The leaves also provide excellent forage for goats. As a timber species they produce fine, hard-grained wood and reproduce readily from stump sprouts once cut.
Mountain Ash (Sorbus spp.): An excellent goat and fowl forage tree. The ash can be pollarded, or cut just above browse height, where it will then sucker profusely. The tender suckers can be fed to livestock as an alfalfa substitute due to their high protein content. Small berry like fruits hang on the branches late into the fall season providing feed for domestic fowl and native bird species.
Mulberry (Morus spp.): Mulberries produce one of the highest protein berries of any fruiting tree. It is a prolific bearer and has a long fruiting season. The leaves are highly desired by livestock while birds and hogs thrive on berries.
Honey Locust (Gleditsia spp.): Another high protein livestock fodder that hangs on the tree late into the dormant season. The pods are devoured by cows, goats, pigs, and are picked apart by chickens. The flowers produce an excellent source of pollen for bees. Trees can be grown to pole diameter then cut for fence posts. Coppicing, or regeneration by suckers from the stump is possible for quick regrowth. Open crown allows light penetration thereby supporting pasture growth below.
Apple (Malus pumila): Leaves and fruit relished by all farm animals. Fruits can be harvested prior to dropping for processing or direct sale.
Russian Olive (Eleagnus angustifolia): Exceptional bird forage and livestock browse. Nitrogen fixer.
Goats: Grass and weed control via browsing. Source of fertilizer.
Yield: meat and dairy products. High-value varieties can be bred.
Domestic & Native Fowl: Deposit nitrogen and phosphorous via droppings.
Insect control. Yield eggs, meat. High-value varieties can be bred.
Food agroforestry systems can be scaled appropriately to almost any site and situation and therefore have very obvious applications in urban settings. Our most productive agricultural lands lie not in the rural landscape however, but within the backyards, empty lots, and open spaces of the urban environment. This fact is easily overlooked or not recognized at all as we have cultivated the assumption that food is best produced on a large scale on lands far removed from the metropolitan area. Historically tracing the development of human settlements shows that villages arose primarily around the most arable and productive soils of a given region - often along the fertile banks of rivers or alluvial floodplains. Currently one of the most pressing issues faced by city planners is the preservation of agricultural lands that lie in the path of urban sprawl. It is a shocking irony that we are presently paving over the most productive soils available to us and replacing them with increasingly consumptive developments. These former agricultural soils have not been entirely lost to us, however, as unproductive lawns, city parks, and other urban open spaces have merely replaced them. It is therefore our opportunity, if we are seeking a measure of sustainability in our methods of food production, to take advantage of these resources inherent within our cities.
We can begin by applying our collective attentions towards planting our neighborhoods with perennial sources of highly nutritious foods in a manner that is both elegant and accessible. Imagine for a moment alleys and roadways lined with majestic chestnuts and walnuts, paths shaded by elegantly arching pears and apples, and neighborhoods sweetened by the spring scent of flowering cherries and plums. The city is rich with resources for the innovative gardener. Compost materials from grocery stores, coffee grinds from espresso shops, wood chips from road utility crews, rainwater catchment from rooftops, and an unlimited labor pool all support a nearly unlimited potential for urban food production.
Additionally, by restoring to health the many neglected fruit and nut trees already in existence within our city limits we can provide for ourselves a perennial and low-maintenance source of fresh produce. The obstacle to urban food sustainability is not a deficit of knowledge or insufficient resources but instead a lack of collective will. Hong Kong is presently producing 75% of its fresh produce within its city limits. This is achieved because urban food production has become inculturated into that society. Let us envision then a renaissance of village gardens and street-side orchards, of markets filled with locally grown produce, for the health and quality of life of any community is dependent upon the health of its agriculture.
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