Conferences and Presentations

Foreword

Foreword contributed by Ramachandran P. K. Nair, Ph.D., Distinguished Professor and Director, Center for Subtropical Agroforestry (CSTAF), School of Forest Resources and Conservation, University of Florida.

Today's farmers and landowners face many challenges as they seek to make their farms and forestlands profitable, productive and environmentally sustainable. A host of problems--farmland conversion, urbanization pressures, reductions in water quality and availability, soil erosion, irregular cash flows, and increased government regulation--make managing the family farm or forest a difficult task.

In today's challenging agricultural setting, new and innovative approaches to farm production are needed. These approaches should address the various problems faced by farmers, landowners and their communities. They should also be practical, profitable, and low in cost.

Various research questions and technology transfer needs are suggested for alley cropping.

The Association for Temperate Agroforestry (AFTA 2000) recently delineated strategic questions and needs for the major agroforestry practices that are equally applicable in subtropical areas. Research questions that need to be addressed for alley cropping focus on compatible crop rotations with tree-shrub species, yields in different combinations, optimal row spacing, weed control at crop-tree row interfaces, and integrated pest management components. Technology transfer needs include region-specific ratings for species combinations, management guidelines, marketing information, financial analysis models, and plant materials information.

Forest farming utilizes forested areas for producing specialty crops that are sold for ornamental, culinary or medicinal uses.

Forest Farming and Nontimber Forest Products (NTFPs)

This practice utilizes forested areas for producing specialty crops that are sold for ornamental, culinary or medicinal uses. Specialty crops that tolerate partial shade include herbs, wildflowers, saw palmetto (Serenoa repens), ferns, mushrooms such as morels (Morchella spp.) and shiitake (Lentinula edodes), and fruits such as plums (Prunus spp.), pawpaw (Asimina triloba), mayhaw (Crataegus opaca), and wild berries.

Figure 3. Forest farming (NAC)

Other nontimber products that can be collected and marketed from shaded conditions are honey, pine straw for mulch, and crafting materials. While many of these products have traditionally been collected from natural sources, in forest farming, intentional management of the crop plants and the overstory trees can increase specialty crop productivity (Figure 3). The overstory trees can also be harvested for timber products, either during regular forest farming operations or in a final harvest. Specialty products produced in forest farm designs can supplement family income and increase product diversity on the site.

The intentional cultivation of diverse products on forested land is practiced successfully all over the world. The multi-storied nature of these systems allows for cultivation of specialty crops at various layers--as belowground root crops, as herbaceous ground covers, as shrubs, as understory trees, and as trees in the canopy. Forest farming is especially useful for commercial production of shade-tolerant specialty crops, species being over-exploited in natural forest settings, and where long-term collecting and sustainability are of concern. In addition, forest farming for specific products can be promoted as part of timber stand improvement, standard silvicultural activities to improve forest value, and management of public lands (Hill & Buck 2000).

Reviews of forest farming practices in North America (Hill & Buck 2000; Dix et al. 1997; Williams et al. 1997; Thomas & Schumann 1993; Smith 1953) and texts on forest gardens (Hart 1991) and homegardens (Nair 1993; Soemarwoto 1987) explain many of the principles of the cultivation systems along with providing examples of which forms these systems take. There are also excellent treatments of nontimber forest products (Jones et al. 2002), forest medicinals (Duke 1997; Davis 1993; Foster 1993; Miller 1988) and their markets in specific regions including the Pacific Northwest (Schlosser & Blatner 1997; Hagen et al. 1996), the Mid-Atlantic (Chamberlain & Hammett 1998; Hill & Webster 1996), the Midwest (Gold & Godsey 2002; Josiah 1999, 2001b; Baughman 1996; Mater 1994), the Rocky Mountains and Southwest (Belonogova 1993; Hernandez & Abud 1987) and the Northeast (Teal & Buck 2002; Buck 1999). Jones et al. (2002) include a brief but commendable description of Florida and the Caribbean area (Weigand 2002) that highlights indigenous cultural uses and the potential for development of medicinal plant cultivation in the U.S. subtropics.

Researchers have identified four major categories of NTFPs: edible and culinary products, medicinal and dietary supplements, floral and decorative products, and specialty wood products.

Chamberlain and Hammett (2002) have identified four major categories of nontimber forest products: edible and culinary products, medicinal and dietary supplements, floral and decorative products, and specialty wood products. Blueberries, huckleberries, honey and mushrooms are examples of the most common edible and culinary products. Witch hazel (Hamamelis spp.), digitalis (Digitalis spp.), camphor (Cinnamomum camphora), saw palmetto and ginseng are all well-known medicinal plants from forested areas. Decorative and floral products include greenery, Spanish moss, dried plants, berries and flowers, wreath materials, and aromatic oils. Products produced from parts of trees, saplings or woody vines, such as furniture, musical instruments, and utensils, are considered specialty wood products.

Apiculture and forest management combine well in forest farming. A number of forest species such as blackgum (Nyssa sylvatica), persimmon, tulip poplar (Liriodendron tulipifera) and gallberry (Ilex glabra), for example, produce nectar and pollen attractive to bees who in turn serve as pollinators and help assure tree seed production for forest regeneration (Alexander & Alexander 2002; Hill & Buck 2000). In addition to honey, a number of products can be developed from beehives, and moving bees and hives on short-term contract as pollinators can be a lucrative business.

Mushroom production is another forest farming activity that has proven to add value to under-utilized wood products and diversify income streams for producers. Native mushrooms, such as chanterelles (Cantharellus spp.) and morels, have long been harvested as edibles, while exotics, such as shiitake and various oyster mushrooms (Pleurotus spp.) are increasingly cultivated for popular markets. Thinning operations in forests that yield small diameter hardwood logs provide the ideal substrate for small scale production of shiitake and other gourmet mushrooms. Small forest patches can also be cleared for mushrooms, such as morels, that prefer forest floor litter as a growth substrate (Hill & Buck 2000; Hill 1999).

Production and marketing of mushrooms has been studied in the Southeast, e.g., shiitake on oak logs under pines in western Alabama (NARC&DC 2000). In addition, cooperative efforts between statewide producers' associations in Alabama and Florida have been developed with partners in Soil and Water Conservation Districts and university extension (Alabama A&M University, Auburn, and University of Florida). In this instance, developing a market for the product was a challenge. Producers who retained steady markets and flexibility with seasonal production and labor demands were able to continue production and in some cases developed year-round enterprises (NARC&DC 2000; Stamets 2000; Sabota 1993; Rathke & Baughmann 1993). Farmer-to-chef markets have been promoted for herbs, mushrooms and specialty vegetables grown in managed forest settings. In south Florida, producers are using melaleuca as a growth substrate for the medicinal Rishi mushroom (Ganoderma sp.) and are cultivating oyster and other edible mushrooms on sawmill waste.

Plant-derived medicines and herbs from forest settings are likely the highest valued trade items.

Markets for herbal supplements have grown significantly over the past ten years. In fact, plant-derived medicines and herbs from forest settings are likely the highest valued trade items (Chamberlain & Hammett 1998, 2002) though formal tracking of marketing is difficult (Alexander et al. 2002). Witch hazel, digitalis, camphor, saw palmetto and ginseng are all well-known medicinal plants from forested areas. Additional forest plants in the Southeast that are used as medicinals include bloodroot (Sanquinaria canadensis), mayapple (Podophyllum peltatum L.), and yellow jasmine (Gelsemium sempervirens). Several medicinal plants that are used in Ayurvedic and homeopathic medicine are native to the West Indies and subtropical America. These species include pond apple (Annona glabra), herb-of-grace (Bacopa monnier), false daisy (Eclipta alba), and llima (Sida cordifolia), among others (Weigand 2002; Demurs 1997; Morton 1981). Markets fluctuate, however, and it is important to understand projected demand and identify buyers for these specialty products (Chamberlain & Hammett 2002; Alexander et al. 2002).

The most widely recognized forest farming activity in the Southeast is gathering pine straw.

The most widely recognized forest farming activity in the Southeast is gathering pine straw, which has increased in popularity since the 1980s (Brauer & Burner 2001; Duryea 1988; McLeod et al. 1987). Under optimal conditions with fertilization management (Morris et al. 1992), this NTFP alternative combined with hunting or other fee uses could add about 20% more income for landowners with mid-rotation longleaf pine stands (Bean 2002). Longleaf and slash pines are preferred for straw because they have longer needles that bale most easily for landscaping mulch and they retain a red or brown color longer than other pines. Though needles can be raked annually, most managers recommend raking only four to five times after year eight during the tree rotation. Maximum needle yield at age 15 is estimated to be 200 to 300 bales per acre (Duryea 2000). Baled pine straw delivered to the seller may earn $750-1000 per acre per year (wide sale range per bale, $0.50 or greater) or $75-150 per acre gathered by a supplier. Once stands are thinned they are seldom used for pinestraw, but they may generate an additional $15 per acre (or more with incorporation of wildlife food plots) from a hunting lease versus $2 per acre in unmanaged forestland (Bean 2002).
DONE TO HERE

Other examples of forest farming include cultivating ferns, palmettos for fronds, or other ornamentals under shade (e.g., oak forest). Greenery products gathered from forests are sold for floral and holiday markets. Tips from lower limbs of conifer trees serve as raw materials for loose greenery, garlands, centerpieces, and wreaths or swags (Hammett & Chamberlain 2002). Numerous broadleaf evergreens and other herbaceous ornamentals exist in the coastal plain vegetation. Early in the 20th century for example, a fern grower's association developed out of Apopka, Florida, to supply asparagus-fern (Asparagus setaceus) to stores in the northeastern U.S. This foliage industry grew as a contract grower-brokerage business and evolved with changing modes of transportation and markets promoting leatherleaf (Rumohra adiantiformis) and asparagus-fern. In 1997 the industry grew floral greens on over 7,300 ac of land in Florida, with sales totaling $85.5 million (FFGA 2001). These fern growers continue today as profitable enterprises with an expanded offering of floral greens, grown under shade of native or managed oak forest.

The history of crafting items from forest-collected materials (wildcrafting), the foliage industry, and the use of medicinals, especially within specific cultural groups, provides an open door for development of forest farming practices in the region (Teal & Buck 2002). However, assessing which understory cropping practices are compatible with timber stand improvement/management and which cultivars are available for use, are questions that need to be addressed (AFTA 2000). We need to compile information on which shade-tolerant species and NTFPs in the region have economic potential, document their growth and management requirements, and determine market strategies with producers. It is also possible NTFPs can be managed on native range (Tanner et al. 1999; Bennett & Hicklin 1998) or integrated into fence lines and riparian forest buffers. The potential for development of NTFP enterprises holds promise not only for the Southeast but also in the Caribbean.

Various research questions and technology transfer needs are suggested for forest farming.

Strategic research questions outlined for forest farming (AFTA 2000) focus on which tree densities and regulated shade levels provide appropriate microclimate and growing conditions for specialty crops, growth requirements for valued NTFPs, start-up/operating costs, compatible forest management strategies, influence of shade levels and genotypes on chemical activity and production gains, evolving markets, and how forest farming compares with other forest land uses. There is also a need to assess the relationships between forest management practices, nontimber forest products, and biodiversity of forest populations (IFCAE 2003).

Technology transfer needs identified for forest farming practices include: wholesale and retail marketing information at region-specific levels; production guidelines that outline species/cultivar information, plant material sources, and compatible forest management regimes; and financial analysis models and enterprise budgets for practices and common specialty crops (AFTA 2000). Promise of buyer, and possibly harvester, involvement in inventorying and monitoring specialty forest products holds effective potential impact for NTFP longevity (IFCAE 2003).

Riparian forest buffers are strips of trees and annual vegetation along stream channels or aquatic shorelines.

Riparian Forest Buffers

This practice is already common in the Southeast since forest landowners maintain vegetation buffer strips along streams according to Forestry Best Management Practices (BMPs) in each state. Basically, riparian forest buffers are strips of trees and annual vegetation along stream channels or aquatic shorelines. Generally speaking, these areas are adjacent to water bodies, have no clear boundary delimitations, serve as transitions between aquatic and upland settings, and are linear in shape and appearance (Schultz et al. 2000). Riparian forest buffers, whether natural or created, have a dominant woody component, unlike vegetative filter strips that are used to intercept surface runoff in agricultural settings. Buffers vary in design according to the intended management objectives (Lowrance et al. 2001; Schultz et al. 2000) including tree crop management (Dosskey et al. 1997a,b; Sykes et al. 1994).

Riparian buffers protect streambanks, slow flood flows, and filter sediment and other contaminants from water.

Figure 4. Riparian forest buffer (NAC: used with permission).

Riparian buffers provide numerous environmental benefits. In general, they play an important role in the hydrologic cycle between surface and ground water, and the movement of non-point source pollution into water bodies (Lowrance et al. 1997; Verchot et al. 1997; Welsch 1991; Lowrance et al. 1985). Specifically, they provide vegetative resistance that serves to trap sediment, slow flood flows, and provide waterbreaks in floodplain areas (Wallace et al. 2000; Daniels & Gilliam 1996). They filter and process runoff, storm water, and drainage from lawns, roads and other urban sites. They also help hold water and control stream bank and in-channel erosion to help stabilize water corridors (Qiu & Prato 1998; Dosskey et al. 1997a,b; Correll 1983).

Riparian buffers also have the capacity to sequester large amounts of carbon through active tree growth (Pallardy et al. 2002; NAC 2000a,b) and play a critical role in maintenance of regional biodiversity (Naiman et al. 1993). In addition, they provide wildlife and aquatic habitat, influence shade, modify winds, screen out noise, and provide aesthetic benefits (Schultz et al. 2000). Riparian zones can thus be managed for environmental services as well as a variety of products, including fruit, nut, and ornamental combinations (Robles-Diaz & Kangas 1999).

Design of riparian buffers will depend on BMP guidelines, site and waterway conditions, and landowner objectives.

The width of the riparian forest buffer depends on BMP guidelines, the condition of the waterway/wetland, and site characteristics such as slope and the type of soil. Landowner objectives may even call for buffer strips wider than BMP guidelines. In agricultural settings, buffer strips can be managed intensively or can be restored by planting strips of perennial vegetation between fields and water. Strips may often be planted in multi-layer patterns where unprotected waterways cross agricultural land (Workman et al. 2002b) (Figure 4). Bioengineering techniques are available for streambank stabilization and restoration in degraded areas (Wells 2002).

Species used in riparian buffers need to be tolerant of occasional flooding or wet soil conditions.

The trees, shrubs and grasses that are suggested for use in riparian buffer strips and streamside management zones need to be tolerant of occasional flooding or wet soil conditions. Those with a well-developed, shallow root system will be more efficient in uptake of nutrients and agrochemicals. Tree species used in these buffers range from cypress (Taxodium spp.) and tupelo (Nyssa spp.) to willows (Salix spp.), maples, poplars, ash and oaks. Shrubs can include wax myrtle (Myrica cerifera), buttonbush (Cephalanthus occidentalis), viburnum (Virburnum spp.), gallberry or other hollies (Ilex spp.). While switchgrass (Panicum virgatum) is often used for a grass buffer strip, any number of native species can also be used in the grass/herb component.

Various research questions and technology transfer needs are suggested for riparian forest buffers.

Research questions that need attention for riparian forest buffer practices include: carbon storage and movement dynamics above- and below-ground; design criteria of age, width and vegetation type; management influences on buffer capacity to process sediments, nutrients and agrochemicals; site characteristics and hydrology influences on buffering capacity and flood protection; variability of buffer effectiveness in different seasons and contaminant loadings; and inclusion of species valued for wildlife habitat or income-generating products (AFTA 2000).

Silvopasture intentionally combines trees with livestock and forage production.

Silvopasture Practices

Figure 5. Silvopastoral systems with cattle grazing bahiagrass in slash pine stand (CSTAF)

Silvopasture intentionally combines trees with livestock and forage production. The Southeast leads the nation in development of this practice because good growing conditions can be maintained for both timber and livestock production on the same site. Benefits to the farmer include income generation while converting from crop to timber (or vice versa), improvement in water quality, wildlife habitat, and soil erosion control. In the Southeast, these systems vary from rotational grazing in pine forests or plantations, to intentional grazing under hardwoods and pecan orchards.

For silvopasture, trees are planted or thinned to provide sufficient light for good forage production. High value timber species can be intensively managed in widely spaced rows, and are most often grouped in double or triple rows to improve form (e.g., double-rows 8 ft apart, 4 ft between trees within a row, and 40 ft to next set of trees). Some landowners have adopted these systems using bahiagrass as a summer forage and clover, ryegrass or rye as a winter forage. Some orchards and woodlots incorporate rotational grazing with cattle, goats, sheep or other livestock.

Various studies have looked at silvopasture in terms of timber production, livestock production, and forage production.

Providing management of the three components of livestock, forage and trees, silvopasture has historically occurred as shade trees in pasture, as grazed orchards or woodlands, and as rangelands that include a managed tree or shrub component (Clason & Sharrow 2000; Robinson & Clason 1997; Williams et al. 1997) (Figure 5). Silvopasture in the Southeast has traditionally included forest grazing with cattle, such as flatwoods rangeland (Pearson 1997), pine managed for turpentine and sawlogs with forage (Byrd et al. 1984; Cary 1928), and tree pasture practices with pecan (Reid 1991). Combinations with goats are of interest for meat production and vegetation management (Burton & Scarfe 1991). The biological limitations and management of each component, and the desired interactions, must be considered during design and species selection (Robinson et al. 2001; Clason & Sharrow 2000; Clason 1999).

The long-term benefits of timber production may attract landowners if it combines easily with their annual livestock and haying operations and provides annual income from wildlife and recreation enterprises.

Other benefits of silvopasture include increased tree growth, forage production, shade for animals, diversified recreation options, and other products such as pine straw. The long-term benefits of timber production may attract landowners if it combines easily with their annual livestock and haying operations and provides annual income from wildlife and recreation enterprises. The initial tree density or designed thinning can be managed to control canopy cover of less than 30% for good forage production. Site disturbance after clearcutting and before replanting can provide an opportunity for planting of forage grasses and legumes.

Lewis and other researchers (Hart et al. 1970) demonstrated that combining the production of southern pines and beef on improved pastures offers an opportunity for multiple product yields. Integrating forestry with ranching may increase profitability and help buffer year-to-year variability in income through the sale of forest products and increased opportunities for sale of hunting leases brought about by the creation of wildlife habitat. Scientists (Lewis et al. 1983; Halls et al. 1957) initiated warm season forage studies under pines in south Georgia in the 1940s that in time showed Pensacola bahiagrass to be the most shade tolerant of the 23 grasses studied (Lewis & Pearson 1987; Pearson 1975). Several legume species have shown potential for production under partial shade (McGraw et al. 2001). In the Georgia trials, annual lespedeza (Kummerowia spp.) and white clover (Trifolium repens) were promising forage species for silvopasture. Double rows of pines at 8 ft between rows and 4 ft between trees and 40 ft wide alleys produced more forage and as much wood as the single 8 ft x 12 ft rows (Lewis et al. 1985), and this remains the most popular spacing for silvopasture across the region today (Clason & Sharrow 2000). Newer varieties of bahiagrass (Tifton-9 and Argentine), with additional research, may show themselves to be even better warm season forage in silvopasture (Nowak & Blount 2002).

Studies from across the southern pine region (e.g., Louisiana, Mississippi, and Georgia), report the possibility of productive livestock grazing while maintaining, or even improving, high value timber production. Silvopastoral practice in Louisiana has shown an internal rate of return that was higher (13%) than managed timber (9%) or open pasture (6%) (Clason 1995). In southern Mississippi, land expectation values of silvopasture combinations of steers/cows compared favorably with pasture and were higher than timber production. Under varied cost and revenue regimes, including fee hunting, silvopasture and pasture both had positive cash flows with pasture overall highest under the short time period evaluated (Grado et al. 2001).