INFLUENCE OF MARKET ORIENTATION ON FOOD DIVERSITY OF FARMS LOCATED ON AMAZONIAN DARK EARTH IN THE REGION OF MANAUS,AMAZONAS,BRAZIL1

JULIE MAJOR,CHARLES R. CLEMENT, AND ANTONIO DITOMMASO

Major, Julie (Department of Crop and Soil Sciences, Cornell University, Ithaca, NY 14853, USA; email: [email protected], phone: 607-255-1730, fax: 607-255-3207), Charles R. Clem- ent (CoordenacËaÄo de Pesquisas em CieÃncias AgronoÃmicas, Instituto Nacional de Pesquisas da AmazoÃnia (INPA), Manaus, ), and Antonio DiTommaso (Department of Crop and Soil Sciences, Cornell University, Ithaca, NY). INFLUENCE OF MARKET ORIENTATION ON FOOD PLANT DIVERSITY OF FARMS LOCATED ON AMAZONIAN DARK EARTH IN THE REGION OF MANAUS,AMA- ZONAS,BRAZIL. Economic 59(1):77±86, 2005. Homegardens may serve as reservoirs of agro-biodiversity on highly fertile, anthropogenic Amazonian Dark Earth (ADE) soils of the . However, as these soils are used more intensively for market-oriented agricul- ture, we suspected a decrease in their agro-biodiversity. We present data obtained from surveys on 16 farms where ADE was present in the region of Manaus, Amazonas, Brazil. When farms were separated into two groups by market orientation, species richness on the farms was not signi®cantly in¯uenced by market orientation, but there was less dominance (i.e., more diver- sity) for homegardens in the low-market orientation group (P Ͻ 0.1). The proportion of native species was not affected by market orientation. Hence, while the most market-oriented farms retained high species richness, homegardens located on them contained higher proportions of commercially interesting species. Key Words: Agro-biodiversity; Amazonia; Amazonian Dark Earth; market orientation; Terra Preta de IÂndio; genetic erosion.

Although homegardens can take an in®nite cated close to dwellings. While cropping pat- number of forms, they are usually characterized terns in the swidden plots may vary from mono- by high species diversity and complex multistra- cultures (e.g., manioc, Manihot esculenta ta architecture (Coomes and Ban 2004; Fernan- Crantz) to multi-crop arrangements [e.g., mani- des and Nair 1986) that constitute an important oc, maize (Zea mays L.), and dry beans (Phas- input to the diet of the household (Nair 1993), eolus sp.) grown together, or manioc with a mix- as well as spices, medicines, stimulants, etc. ture of trees], the diversity of these swidden (Trinh et al. 2003). They also provide shade near plots is always less than that in the homegar- living areas while reducing erosion in high-rain- dens. Such cropping patterns are also found on fall regions (Jose and Shanmugaratnam 1993). farms located on areas of Amazonian Dark Earth Homegardens can serve as key elements in the (ADE, locally known as Terra preta de Indio). conservation of on-farm biodiversity (Eyzaguir- These are highly fertile soils formed at the lo- re, Martin, and Barrow 2001; Trinh et al. 2003), cation of indigenous settlements in pre-Colum- for example by offering refugia for species bian times (Smith 1980; Woods, McCann, and whose importance is diminishing, and by serv- Meyer 2000). Their fertility is usually consid- ing as testing nurseries for new plant species or erably greater than that of surrounding local varieties (Eyzaguirre, Martin, and Barrow 2001). soils; ADE soils exhibit higher pH, phosphorus, Farms of traditional smallholder populations and organic matter contents, as well as higher in Amazonia are usually composed of several cation exchange capacity (Kern and KaÈmpf swidden agriculture plots and a homegarden lo- 1989; Lehmann et al. 2003). The production of high-value crops (e.g., vegetables) is possible on 1 Received 13 September 2004; accepted 22 Novem- ADE without the often prohibitive amounts of ber 2004. external inputs that would be necessary on sur-

Economic Botany 59(1) pp. 77±86. 2005 ᭧ 2005 by The New York Botanical Garden Press, Bronx, NY 10458-5126 U.S.A. 78 ECONOMIC BOTANY [VOL. 59

Fig. 1. Location of surveyed farms on Amazonian Dark Earth in the central Brazilian Amazon. rounding Oxisols and Ultisols. Where access to crop diversity on farms on which ADE soils oc- market is good, ADE soils can be managed for curred near the city of Manaus, the largest urban permanent crop production (Hiraoka et al. market in the central Brazilian Amazon. 2003), including mechanized operations. In more remote areas, subsistence agriculture is MATERIALS AND METHODS practiced on these soils and a wide range of EXPERIMENTAL PROCEDURE crops is produced, especially horticultural spe- cies. From January to June 2003, the primary au- Greater market orientation has been linked to thor visited 16 households located on ADE in greater soil nutrient de®cits on small farms in eight communities of the Manaus region (Fig. Kenya (de Jager et al. 1998), to decreases in 1). Farms were chosen based on accessibility homegarden architectural complexity in Guate- (i.e., farms were known and could be visited mala (Gillespie, Knudson, and Geilfus 1993), while carrying out other research activities in- and to decreases in homegarden biodiversity in volving surveys of agricultural weeds and con- Indonesia (Soemarwoto 1987) and Mexico (Fey trolled maize growth experiments, or during a 1988). By offering the possibility to grow high- three-day boat expedition) and the possibility to value crops more economically, ADE soils and conduct the interview at the time the farm was the farms located on them may be at greater risk visited. The market locations found near the of losing agro-biodiversity as cropping activities sampled sites included Manaus, Manacapuru, become more market-oriented (Clement, Mc- Rio Preto da Eva, and Novo AiraÄo (Fig. 1). On- Cann, and Smith 2003). We undertook this study farm diversity was assessed by surveying both to describe homegardens found on ADE and as- the homegarden and all agricultural plots. sess whether greater market orientation lead to The area and number of crops grown on each losses of total and native food and condiment farm plot were recorded, and the person who 2005] MAJOR ET AL.: DIVERSITY ON AMAZONIAN DARK EARTH 79 managed these and the marketing of produce also varied (e.g., river transport included pad- was interviewed about the level of commercial- dling a canoe, small outboard motor-driven ca- ization. Usually a man was interviewed, and in noes, and larger boats with diesel motors). one case each a woman and a couple were in- Simpson's index of dominance (C) was cal- terviewed. The homegarden of each farm was culated for the homegardens as: identi®ed as an area adjacent to the dwelling, s ϭ ͸ 2 and de®ned in space by the owners when asked C (pi) about their quintal (homegarden). It was ana- iϭ1 lyzed in detail: food crop and condiment species where pi is the proportion of individuals repre- were identi®ed and numbers of individuals sented by each species in the sample. Domi- counted. Other agricultural plots were generally nance relates to skewness in the representation referred to as rocËa or rocËado (forest clearing, of species in the sample, i.e., high dominance plantation). that served strictly medicinal means a few species are represented by many or other purposes were omitted to avoid issues individuals, while other species are represented of access to traditional knowledge associated by only a few individuals. This value was not with Brazilian biodiversity laws, even though computed for cropped plots due to the lack of homegardens are rich in medicinal species. individual counts. Species richness (number of species ob- DATA ANALYSIS served) was calculated for the homegardens and Market orientation has been de®ned in many for cropped plots. In the case of homegardens, ways that vary in rigidity and emphasis. Exam- species richness was also analyzed on a per 100 ples of de®nitions include the percentage of total m2 basis. For the majority of studied farms, the output sold to outside markets (de Jager et al. dwellings and the homegardens occurred on 1998), and researcher perceptions of accessibil- ADE, while agricultural plots often extended ity to markets via roads (Gillespie, Knudson, outside this area through regions of transitional and Geilfus 1993). We calculated market orien- soil (locally known as Terra mulata) and onto tation as the area planted to crops destined to be adjacent soils (non-ADE, Terra comum, barro). sold in outside markets [e.g., papaya (Carica pa- For whole-farm analyses, the total number of paya L.), bell peppers (Capsicum annuum L.), species found in the homegarden was added to okra (Abelmoschus esculentus L. Moench)], di- the average number of species found on each vided by the total area of the farm under culti- cropped plot of the farms. We used plot averages vation at the time of the visit, excluding land in because some farmers planted many small, fallow, which is similar to the de®nition of de monoculture plots of a number of species. Total Jager et al. (1998). In the cases where farmers species numbers for farmed plots would be high reported selling manioc ¯our and surpluses of in this case, but the plots are not necessarily di- other subsistence crops (e.g., maize, beans), we verse. Immature and non-producing individuals included half the area of these plots in the cal- were included in the analysis. culation of the area planted to marketed crops. Linear regression analyses were performed The proportion of subsistence produce sold from using the GLM procedure in SAS (SAS Institute the agricultural plots varied with crops and 2001). Data transformation for species richness among farms and harvests, and no speci®c data was deemed unnecessary after evaluating diag- relating to marketed proportions were obtained. nostic plots, and Simpson's index was logarith- For this reason and based on observations, a val- mically transformed to stabilize variance. ue of one-half was used. We did not consider distance or time to mar- RESULTS ket because of high variability in the arrange- A total of 79 food and condiment plant spe- ments different farmers had. For example, some cies were observed in the homegardens (Table farmers knew transport agents that took their 1), of which 35 are native to Amazonia and im- produce free of charge, others bene®ted from mediately adjacent regions. Three of the four governmental programs for produce transport, most frequent species were exotics [mango while others traveled to different market loca- (Mangifera indica L., frequency (f) ϭ 15), co- tions according to the type of produce at hand conut (Cocos nucifera L., f ϭ 13), and citrus or its quantity. The means of traveling to market (Citrus spp., f ϭ 13)]. The most frequent native 80 ECONOMIC BOTANY [VOL. 59 , 9 1 1 2 3 1 1 1 1 1 5 2 3 2 3 Ð Ð Ð Ð Ð Ð Ð Ð Ð Ð Ð Ð Ð Ð Ð Ð Ð Ð Ð Agricul- ANAUS tural plot frequency M 1 3 5 3 2 1 6 1 2 7 4 3 9 1 2 2 9 2 1 2 3 1 5 1 1 11 Ð Ð Ð 10 13 10 11 15 garden Home- frequency ARTH NEAR E ARK D MAZONIAN A L. Meyer (Bertol.) Kuntze MAZONIAN OR NEOTROPICAL AND INTRODUCED TO L. A Mart. L. L. L. L. L. L. L. L. (L.) R.K. Jansen L. L. Jacq. L. Mart. Macf. Mart. (Thunb.) Matsum. & Nakai (L.) Lam. (L.) Merril Kunth Mart. Baill. L. L. L. L. L. (Kunth) Cortes L. ATIVE SPECIES ARE Carica papaya Platonia insignis Ipomoea batatas Citrullus lanatus Cucumis anguria Bixa orellana Brassica oleracaea Brassica oleracaea Raphanus sativus Ananas comosus Lactuca sativa Acmella oleracea Elaeis oleifera Euterpe oleracea Mauritia ¯exuosa Oenocarpus bacaba aculeatum Attalea speciosa Bactris gasipaes Cocos nucifera Elaeis guineensis Daucus carota Eryngium foetidum Araucaria angustifolia Annona squamosa Rollinia mucosa Annona muricata Coriandrum sativum Cuminum cyminum Anacardium occidentale Mangifera indica Spondias mombim Annona glabra Annona montana ). N N N E E E N E E E N N N N N N N N E E E N E N N N E E N E N N N Exotic Scienti®c name Native/ FARMS 16 ϭ N ( Papaya Sweet potato Watermelon West Indian gherkin Annatto Cabbage Radish Pineapple Lettuce E American oil palm N Peach palm African oil palm Carrot Chicory Parana pine Sugar apple Soursop Cilantro Cumin Cashew Mango Hog plum Pond apple Mountain soursop 1999). LEMENT Â Ä Â Ã Äo  Ëu Äo  WITH THEIR FREQUENCY OF OCCURRENCE Ëaõ , Mama Bacuri Batata doce Melancia Maxixe Urucum Couve Repolho Rabanete Abacaxi Alface Jambu Caiaue Ac Buriti Bacaba Cenoura Chicoria Pinha Tucuma Babac Pupunha Coco Dende Ata Biriba Graviola Coentro (cheiro verde) Cominho Caju Manga Tapereba Condessa Araticum 1500 A.D. (C RAZIL OOD CROP AND CONDIMENT SPECIES FOUND IN HOMEGARDENS AND AGRICULTURAL PLOTS ON ,B 1. F Family Local common name English name MAZONAS MAZONIA BEFORE ABLE Caricaceae Clusiaceae Convolvulaceae Cucurbitaceae Cucurbitaceae Bixaceae Brassicaceae Brassicaceae Brassicaceae Bromeliaceae Asteraceae Asteraceae Arecaceae Arecaceae Arecaceae Apiaceae Apiaceae Araucariaceae Arecaceae Arecaceae Arecaceae Arecaceae Arecaceae Annonaceae Annonaceae Anonaceae Apiaceae Apiaceae T A Anacardiaceae Anacardiaceae Anacardiaceae Annonaceae Annonaceae A 2005] MAJOR ET AL.: DIVERSITY ON AMAZONIAN DARK EARTH 81 1 2 1 2 1 1 3 2 8 2 1 2 5 7 1 7 1 1 1 5 Ð Ð Ð Ð Ð Ð Ð Ð Ð Ð Ð Ð Ð Ð Agricul- tural plot frequency 1 4 6 6 6 1 2 4 1 2 3 1 1 6 1 5 1 6 1 6 2 1 1 1 Ð Ð 11 12 15 11 11 Ð Ð Ð garden Home- frequency Lam. (L.) Moench L. L. Ducke (L.) Rich DC L. (L.) Merr. & L.M. Perry (DC) Stapf L. Duchesne H&B L. L. Crantz L. Mill L. Benth. (Parkinson) Fosberg McVaugh L. f. L. (L.) Skeels Sims.f. L. (L.) Millsp. L. L. L. Merrill. Mart. sp. . Cajanus cajan Piper nigrum Cymbopogon citratus Oryza sativa Saccharum of®cinarum Syzygium malaccense Syzygium cumini Averrhoa carambola Passi¯ora edulis Sesamum orientale Bertholletia excelsa Eugenia stipitata Psidium acutangulum Psidium guajava Abelmoschus esculentus Artocarpus altilis Artocarpus heterophyllus Ficus carica Musa Poraqueiba paraensis Persea americana Allium schoenoprasum Brysonima crassifolia Malpighia punicifolia Cucumis sativus Cucurbita moschata Dioscorea tri®da Manihot esculenta Inga cinnamomea Ina edulis Tamarindus indica Arachis hypogaea Glycine max Phaseolus vulgare ONTINUED E E E E E E E E N E N N N N E E E E E N N E N N E E N N N N E E E N Exotic Scienti®c name Native/ 1. C ABLE T Pigeon pea Black pepper Citronella Rice Sugar cane Malay apple Jambolan Star fruit Passion fruit Sesame Brazil Guava Okra Fig Banana Avocado Chives Nancy Barbados cherry Cucumber Squash Manioc Ice-cream bean Peanut Soybean Dry beans Ëa)  Ëucar   Äo Ëu Äo Ëa-boi Ëa-pera (goiaba arac  Âac  cipo Âbora Guandu Pimenta do reino Capim santo Arroz Cana de ac Jambo Azeitona Carambola Maracuja Jerjelim Castanha do Para Arac Arac Goiaba Quiabo Fruta pa Jaca Figo Banana Pepino Abo Cara Mandioca Inga Inga Tamarindo Amendoim Soya Feija Mari Abacate Cebolinha Murici Acerola Family Local common name English name Fabaceae Piperaceae Poaceae Poaceae Poaceae Myrtaceae Myrtaceae Oxalidaceae Passi¯oraceae Pedaliaceae Myrtaceae Myrtaceae Myrtaceae Myrtaceae Malvaceae Moraceae Moraceae Moraceae Musaceae Cucurbitaceae Cucurbitaceae Dioscoreaceae Euphorbiaceae Fabaceae Fabaceae Fabaceae Fabaceae Fabaceae Fabaceae Icacinaceae Lauraceae Liliaceae Malpighiaceae Malpighiaceae 82 ECONOMIC BOTANY [VOL. 59 2 1 1 1 1 3 1 1 5 6 Ð Ð Ð Ð Ð Ð Ð Ð Ð Agricul- tural plot frequency 7 4 1 3 1 1 8 4 1 1 5 2 3 1 1 1 Ð 13 Ð garden Home- frequency Mill. (Willd. ex. Spreng.) Schum. 12 4 L. L. (L.) Juss. L. L. L. L. L. (St.Hil.) Radlk (Ruiz et Pavon) Radlk L. (L.) Batsch. L. chinensis Jacq. chinensis Jacq. L. spp. spp. . Capiscum Lycopersicon esculentum Solanum melongena Theobroma cacao Theobroma grandifolium Nephelium lappaceum Talisia esculenta Pouteria caimito Capiscum annuum Capiscum Prunus Pyrus communis Coffea arabica Genipa americana Citrus Zea mays Talinum fruticosum Punica granatatum Prunus armeniaca Prunus persica ONTINUED E E E N E N N E E E E E N E E N E E E Exotic Scienti®c name Native/ 1. C ABLE T Hot pepper Tomato Eggplant Cocoa Rambutan Bell pepper Sweet pepper Cherry Pear Coffee Genipap Citrus Maize Pomegranate Apricot Peach 1 1 Äo Ëu N 1  1  Âtricos Ãssego Pimenta forte Tomate Beringela Cacao Rambutan Pitomba Abiu Pimenta Pimenta de cheiro Cereja Milho Cariru Roma Abricot Pe Pera Cafe Jenipapo Cõ Family Local common name English name Temperate species which are not expected to bear fruit in the Manaus region. 1 Sterliculiaceae Capuac Solanaceae Solanaceae Solanaceae Sterliculiaceae Sapindaceae Sapindaceae Sapotaceae Solanaceae Solanaceae Rosaceae Rosaceae Rubiaceae Rubiaceae Rutaceae Poaceae Portulacaceae Punicaceae Rosaceae Rosaceae 2005] MAJOR ET AL.: DIVERSITY ON AMAZONIAN DARK EARTH 83

Fig. 2. Relationship between species richness for the whole farm and species dominance (Simpson's index C) in homegardens of 16 farms with different market orientation located on Amazonian Dark Earth in the region of Manaus, Amazonas, Brazil. species were avocado (Persea americana Mill, cies appeared only in the homegardens supports f ϭ 15), cupuacËu (Theobroma grandi¯orum the assertion that the latter are more diverse than Schum., f ϭ 12), guava (Psidium guajava L., f agricultural plots, which was also observed in ϭ 11), ice-cream bean (Inga edulis Mart., f ϭ Amazonian homegardens of Peru (Coomes and 11), and cashew (Anacardium occidentale L., f Ban 2004). Species that appeared only in agri- ϭ 11). Avocado, guava, and cashew all arrived cultural plots include staple foods [e.g., rice in Amazonia before European conquest (Clem- (Oryza sativa L.), maize, dry bean], as well as ent 1999) and are thus treated as native species. horticultural crops that are produced for market On both whole-farm and homegarden bases, the {e.g., bell pepper, lettuce [Lactuca sativa L.], proportion of native species was not signi®cant- and watermelon [Citrullus lanatus (Thunb.) ly affected by market orientation, and was on Matsum. & Nakai]}. The most frequently re- average slightly above 50%. corded species in agricultural plots were papaya Many species occurred at low frequencies, il- (f ϭ 9), banana (Musa sp., f ϭ 8), maize (f ϭ lustrating the variability in homegardens sam- 0.6), manioc (f ϭ 7), and squash (Cucurbita pled. One homegarden contained numerous Eur- pepo L., f ϭ 7). While banana and squash are asian exotics that the non-Amazonian owners often intercropped or planted on the edges of hoped to adapt to Amazonia [e.g., peach (Prunus ®elds, papaya frequently appears voluntarily in persica L. Batsch.), pear (Pyrus communis L. plots and is tended. Sand)]. Another remarkably different farm is With data from the ``self-suf®cient'' farm in- characterized by no market orientation, high cluded and farms not separated into groups, mar- species richness, and low dominance (high even- ket orientation did not have a signi®cant effect ness in species representation) (Fig. 2). This on species richness (for the homegarden alone, household was composed of ideologically dis- as a whole or on a 100 m2 basis, or for the whole tinct individuals who strived to attain total self- farm) or dominance. The other 15 farms can be suf®ciency, and is hereafter referred to as the separated into two groups according to market ``self-suf®cient'' farm. orientation (Table 2). With data from the ``self- Forty-six species were observed on agricul- suf®cient'' farm removed, the ``low'' market ori- tural plots (including non-ADE). Of the total entation group (mean market orientation Ͻ 0.6) number of species observed (79), 48% appeared had a slightly higher mean species richness for in homegardens but never in agricultural plots, the whole farm as well as for the homegarden while 11% appeared in agricultural plots but only, although differences were not signi®cant never in homegardens. The fact that more spe- (Table 3). This group also had lower dominance, 84 ECONOMIC BOTANY [VOL. 59

TABLE 2. CHARACTERISTICS OF STUDY SITES IN CENTRAL BRAZILIAN AMAZONIA.

Agricultural plots Whole farm Homegarden Market Market Average orientation orientation Farm1 Area2 (ha) # sp.3 Area (ha) # sp. C4 Area (ha) # sp. fraction5 group 1 0.84 39 0.04 32 2.14 0.80 1.8 0.25 Low 2 0.64 29 0.04 25 2.56 0.60 2.8 0.47 Low 3 0.40 46 0.09 43 2.48 0.31 3.8 0.32 Low 4 7.01 17 0.01 15 1.30 7.00 1.3 1.00 High 5 6.01 15 0.01 7 0.77 6.00 1.3 1.00 High 6 6.54 31 0.04 13 2.31 6.50 27.0 0.46 Low 7 3.86 17 0.04 9 1.12 3.82 1.3 0.78 High 8 5.04 23 0.04 18 2.08 5.00 1.2 0.99 High 9 1.04 23 0.09 20 1.86 0.95 1.0 0.38 Low 10 0.63 24 0.04 13 1.93 0.59 2.3 0.29 Low 11 0.74 19 0.04 17 2.45 0.70 1.5 0.34 Low 12 0.09 20 0.04 18 2.41 0.05 2.0 0.22 Low 13 1.80 23 0.13 14 2.46 1.67 2.3 0.46 Low 14 0.25 50 0.25 44 3.73 0.00 22.5 0.00 Low 15 56.04 36 0.04 34 2.39 56.00 1.0 1.00 High 16 5.60 27 0.10 26 2.41 5.50 1.0 0.98 High

1 See Figure 1. 2 Area under cultivation. 3 Number of species. 4 Simpson's index of dominance. 5 Area farmed for market/total area farmed. in the homegarden, compared with the ``high'' study did contain such soils, although data are market orientation group (P Ͻ 0.1). not presented or analyzed according to soil type, and no indication is given as to the frequency DISCUSSION and extent of ADE in the sampled gardens. The The homegarden food and condiment plant di- high frequency of exotics in Amazonian home- versity obtained here (79 species) is greater than gardens has been observed in areas close to our for a survey of 20 rural and 21 urban homegar- ADE homegardens, for example in Rio Preto da dens in the region of SantareÂm, ParaÂ, Brazil Eva and Bela Vista (in Manacapuru) (Noda (WinklerPrins 2002), and a study of 24 home- 2000) and further away on the upper Amazon gardens in a peasant village near Iquitos, Ama- River (Clement et al. 2001). In Rio Preto da Eva, zonian Peru (Coomes and Ban 2004), where 47 avocado, Citrus spp., mango, and banana (Musa and 42 such species were identi®ed, respective- spp.) were most frequent; in Bela Vista, avoca- ly. While the Peru study does not mention the do, Citrus spp., mango, and coffee (Coffea spp.) presence of ADE, some gardens in the Para were most frequent; along the upper Amazon,

TABLE 3. MEANS (Ϯ SE) FOR MARKET-ORIENTED AREA AS A PROPORTION OF TOTAL AGRICULTURAL AREA, SPECIES RICHNESS, AND SIMPSON'S DOMINANCE INDEX FOR TWO MARKET ORIENTATION GROUPS OUT OF 16 FARMS LOCATED ON AMAZONIA DARK EARTH SOILS IN THE REGION OF MANAUS,AMAZONAS, BRAZIL.DIFFERENT LETTERS REPRESENT SIGNIFICANTLY DIFFERENT VALUES (P Ͻ 0.1).

Market orientation Market area/total* Species richness Dominance (C) LOW (n ϭ 10) ``self-suf®cient'' farm included 0.32 Ϯ 0.14 31 Ϯ 17 0.14 Ϯ 0.07 LOW (n ϭ 9) ``self-suf®cient'' farm excluded 0.35 Ϯ 0.09 26 Ϯ 12 0.15 Ϯ 0.07a HIGH (n ϭ 6) 0.96 Ϯ 0.09 20 Ϯ 11 0.28 Ϯ 0.16b

* Area farmed for market/total area farmed. 2005] MAJOR ET AL.: DIVERSITY ON AMAZONIAN DARK EARTH 85 banana, jambo (Syzygium malaccensis L.), Cit- to put the farm up for sale at the time of the rus spp., and coconut were most frequent. Clem- interview. It is likely that a frequent change in ent, McCann, and Smith (2003) observed that ownership, combined with almost complete mar- exotic species perform better on ADE than ad- ket orientation, will lead to the erosion of spe- jacent Oxisols and Ultisols because of better cies richness at this location. growing conditions. Our observations con®rm this. CONCLUSIONS Others have reported declines in on-farm bio- Hiraoka et al. (2003) suggested that species diversity as opportunities for commercialization diversity in homegardens on ADE varies more increased (Fey 1988; Soemarwoto 1987). Our according to the tastes of its owners and the ®ndings are in agreement with those of Trinh et availability of propagation material than with lo- al. (2003), who reported that despite anecdotal cation, although favorable location is important evidence from research sites in Vietnam that in- for market orientation. We hypothesized that in- creased commercialization of homegarden prod- creased market orientation would decrease sub- ucts lead to decreases in agro-biodiversity, ac- sistence reliance on the homegarden for tual data did not support this hypothesis. How- and vegetables. Decreases in agro-biodiversity ever, Trinh et al. did observe a reduction in the on ADE soils would be especially troublesome number of species with increased market orien- because a number of species are associated with tation, when species richness was compared on them through their indigenous origin and are not a per 100 m2 basis. This was not the case here. valued in modern markets [e.g., caiaueÂ, Elaeis Although Trinh et al. (2003) did not report oleifera (Kunth) Cortes] (Clement, McCann, and dominance measures in their study, they did al- Smith 2003). While the diversity of other crops lude to the increasing number of monocultures often remained high, our data indeed show that of commercially valuable species within the dominance in the homegarden is increased with homegarden for households with a strong market increased market orientation, mostly because of orientation, a trend which results in increased the production of commercially interesting spe- plant dominance. An important difference be- cies. tween our assessment in this study and that of Our study shows that commercialized home Trinh et al. (2003) is that the latter based their gardens can maintain species diversity, but they evaluation of market orientation only on the also tend to show increased dominance of highly commercialization of products from the home- marketable species. Our data set should be garden, and not from cropped ®elds, whereas we viewed as a snapshot of the dynamic interaction evaluated commercialization on a whole-farm between traditional farmers and modern econo- basis. mies, and can serve as a baseline for future The two farms in the ``high'' market orienta- work. tion group with the highest species richness (Fig. 2) are both located in Rio Preto da Eva (Fig. 1, ACKNOWLEDGMENTS farms 15 and 16), a community with easy and We would like to thank the farmers who participated in this study, J. rapid access to the metropolitan area of Manaus. Max GonzaÂlez Rozo for designing maps, and Dr. David R. Lee at Cornell University for guidance with writing this paper. Funding was provided The owner of one of these farms is originally by the Saltonstall Fellowship of the Department of Crop and Soil Sci- from subtropical southern Brazil, and 21% of the ences at Cornell University, the Fonds QueÂbeÂcois de Recherche sur la species found in his homegarden are exotic to Nature et les Technologies, and travel grants from the Cornell Interna- tional Institute for Food, Agriculture and Development and the Einaudi the Amazon and highly unlikely to bear fruit Center for International Studies, at Cornell University. Dr. Antoinette [e.g., grapes (Vitis vinifera L.), apricots (Prunus M.G.A. WinklerPrins of the Department of Geography, Michigan State University, and three anonymous reviewers provided valuable comments armeniaca L.), and cherries (Prunus spp.)]. The on earlier versions of the manuscript. high market orientation farm with the second highest species number is characterized by an LITERATURE CITED aging homegarden composed primarily of ma- Clement, C. R. 1999. 1492 and the loss of Amazonian ture fruit trees. Little investment is made in crop genetic resources. Part 1. The relation between planting new trees, except for a small monocul- domestication and human population decline. Eco- ture of high market value soursop (Annona mur- nomic Botany 53:188±202. icata L.). The garden was diverse when the pres- , J. M. McCann, and N. J. H. Smith. 2003. ent owner bought the property, and he was about Agrobiodiversity in Amazonia and its relationship 86 ECONOMIC BOTANY [VOL. 59

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