pergunta4

(

Mauritia flexuosa L. f., Arecaceae) in the Jalapão Region,

Central Brazil

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2_{PEQUI-Pesquisa e Conservação do Cerrado, SCLN 408, Bloco E, Sala 201, CEP 70.856-550,}

Brasília-DF, Brasil

3_{Departamento de Botânica, Programa de Pós-Graduação em Biologia Vegetal, Instituto de Biologia,}

CP 6109, Universidade Estadual de Campinas-UNICAMP, CEP 13.083-970, Campinas-SP, Brasil

4_{IBAMA-Instituto Brasileiro de Meio Ambiente e Recursos Naturais Renováveis, SCEN Trecho 2,}

CEP 70.818-900, Brasília-DF, Brasil

5_{Botany Department, University of Hawai’i at Manoa, 3190 Maile Way, Room 101, Honolulu, HI}

96822, USA

6_{Instituto Sociedade, População e Natureza, SCLN 202, Bloco B, Salas 101/104, CEP 70.832-525,}

Brasília-DF, Brasil

*Corresponding author; e-mail: [email protected]

Harvesting Effects and Population Ecology of Buriti Palm (Mauritia flexuosa L. f., Arecaceae) in the Jalapão Region, Central Brazil. Buriti palm is used for several purposes in Jalapão, Brazil, among which harvesting of young leaves has the greatest potential impact on palm populations. This work aimed to (i) assess buriti palm uses, (ii) identify experimentally the impacts of young-leaf harvesting on growth, survival, and leaf production of individuals, (iii) evaluate density and structure of buriti populations at different distances from a local harv-ester community, and (iv) quantify thefiber yield of young leaves. We conducted 21 inter-views, sampled six buriti palm populations, and monitored 60 buriti individuals to evaluate the impacts of harvesting young leaves. The harvesting practices of artisans did not affect the survival, leaf production, or growth of buriti individuals. The buriti palm is abundant and has a “reverse J” population structure, indicating population regeneration. However, some signs of overexploitation were pointed out by local harvesters and observed in thefield; therefore, we recommend management practices that would contribute to sustainability, such as harvesting young leaves from individuals with a large number of mature green leaves, and harvesting young leaves in sites far from the communities.

Efeitos do Extrativismo e Ecologia Populacional de Buriti (Mauritia flexuosa L. f., Arecaceae) na Região do Jalapão, Tocantins, Brasil. Buriti é usado para inúmerasfinalidades no Jalapão, dentre elas, o extravismo de folhas jovens tem o maior potencial de impacto nas populações. Este trabalho teve por objetivos (i) descrever os usos do buriti, (ii) testar impactos do extrativ-ismo de folhas jovens no crescimento, sobrevivência e produção de folhas dos individuos, (iii) caracterizar a densidade e estrutura de populações em veredas a diferentes distâncias da co-munidade da Mumbuca, e (iv) quantificar a produção de fibras obtidas das folhas jovens. Fizemos 21 entrevistas com extrativistas, amostramos seis populações de buriti e monitoramos 60 indivíduos para avaliar os impactos do extrativismo. O extrativismo não afetou a sobreviv-ência, a produção de folhas e nem o crescimento dos indivíduos. As populações de buriti são abundantes e tem estrutura em formato de J invertido, o que facilita a regeneração. Sinais de superexploração foram identificados por artesãos e verificados em campo, por isto, recomen-damos algumas práticas de manejo que podem contribuir para a sustentabilidade do extrativ-ismo, como coletar folhas jovens de indivíduos com maior número de folhas maduras e em veredas mais distantes das comunidades.

Key Words: NTFP, Population structure, Leaf harvest, Cerrado, Golden grass.

Economic Botany, 62(2), 2008, pp. 171–181

© 2008, by The New York Botanical Garden Press, Bronx, NY 10458-5126 U.S.A.

1_{Received 3 November 2007; accepted 10 April 2008;}

Introduction

The harvest of non-timber forest products (NTFPs) can be an alternative form of land use, promoting biodiversity conservation while pro-viding income to rural communities (Nepstad and Schwartzman 1992; Panayatou and Ashton

1992). However, natural resources can become depleted by intensive and uncontrolled harvesting (Ticktin 2005). The effects of harvesting are species-specific and can vary according to the ecosystem, region, and management practices adopted (Endress et al.2006; Runk et al.2004). To combine effectively conservation and income generation, it is essential to assess experimentally the ecological impacts of NTFP harvest.

The effects of NTFP harvest can be assessed by comparing the survival, growth, and reproduction rates of individuals subjected to different harvest-ing intensities (Kathriarachchi et al. 2004; Uma Shaanker et al.2002). Since changes in these rates can affect population structure, comparisons of structure among populations subjected to differ-ent harvesting intensities can potdiffer-entially reveal harvesting impacts over time (Murali et al.1996; Peres et al.2003).

Palm species provide a wide range of NTFPs to local communities around the world, and almost all parts of palms are harvested. Expanded palm leaves are harvested for handicrafts and roofing (Peters et al.2007; Svenning and Macia 2002), whereas the unopened young palm leaves are used to make twine or fibers and delicate handicrafts (Balick1979; Runk et al.2004).

Harvesting of mature palm leaves has been reported to increase mortality and to reduce growth and reproductive rates in some palms species (Endress et al. 2004; Ratsirarson et al.

1996), but only one study that we are aware of has reported the effects of harvesting unopened young leaves on palm individuals and populations. Joyal (1995) found that leaf production declined after the experimental harvest of young leaves in juveniles of Sabal uresana Trel., whereas harvesting mature leaves in the same species did not affect the rate of leaf production. Leaf life span is the main factor affecting the net carbon profit of a leaf to an individual plant (Chabot and Hicks1982). Young leaves are harvested when completely formed, but not expanded; thus their production costs cannot be paid back through photosynthesis. In contrast, when mature leaves are harvested, palms might be

able to recover at least the initial carbon invest-ment in the leaf production (Joyal1995).

Young leaves are harvested from buriti palm (Mauritiaflexuosa L.f.) to obtain strips (known as “buriti silk”) used in the large-scale production of handicrafts in the northeastern region of Brazil (especially in the state of Maranhão). They are also used to sew handicrafts of Syngonanthus nitens (Bong.) Ruhland (Eriocaulaceae) scapes (flower stalks) in some regions of the Tocantins state, especially in the Jalapão region (Schmidt et al. 2007). The handicrafts made from S. nitens (known as “golden grass”) and buriti palm strips (Fig. 1) have been one of the most important sources of income for families, and especially for women, in the Jalapão region since the mid 1990s (Schmidt et al. 2007). Despite the high abundance of buriti palms in most of the Brazil-ian territory (Henderson et al. 1995) and the intense use of many parts of buriti palms for food, oil extraction, roofing, and handicrafts (Balick

1988; Castro2000), few studies have focused on the species ecology (Cardoso et al. 2002; Ponce Calderón2002; Ponce et al.1999) and the effects of harvest on buriti palm populations have not been previously evaluated.

The aims of this study were to (i) assess buriti palm uses, harvesting, and management techniques applied by harvesters from Mumbuca, a local community in the Jalapão region, (ii) assess experi-mentally the effects of young-leaf harvesting on the survival, leaf production, and relative growth rates of the individuals over a one-year period, (iii) assess the effects of harvesting on buriti palm populations by characterizing the density and structure of buriti populations at six sites within varying distances from the community, because harvesting intensity of NTFP tends to be inversely related to the distance from local communities (Murali et al. 1996; Uma Shaanker et al. 2002), and (iv) quantify the fiber yield of young leaf and identify the plant character-istics that may influence it. This study is part of a broader project that started in 2002 in response to a request from the Mumbuca community artisans association and aims to contribute to the ecological and economic sustainability of handicraft activities in the Jalapão region.

Material and Methods

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The Jalapão region covers an area of 53,340 km2and is located in the eastern part of

Tocantins state, within the Cerrado biome (Fig. 2) - a savanna-like vegetation that is a biodiversity hotspot and originally covered 2 million km2, mostly in the central part of Brazil

(Klink and Machado 2005; Myers et al. 2000). The average annual temperature in Jalapão is 27° C and annual precipitation is 1,700 mm. On average, 90% of the rains occur from October to April (Seplan2003).

Buriti palms form narrow swamp forests (10– 50 meters wide) along watercourses in poorly drained hydromorphic soils surrounded by humid grasslands in the Cerrado. These swamp forests form canopies, albeit discontinuous, where dicot-yledonous trees occur infrequently (Ratter et al.

1997).

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The buriti palm is a dioecious, arborescent palm up to 25 m tall, with a single stem. It occurs from the north of South America in the Amazonian region east of the Andes down to the central portion of Brazil in the states of São Paulo and Mato Grosso do Sul (Castro 2000; Henderson 1995; Henderson et al. 1995; Pott and Pott 2004). The species holds very high importance to local communities throughout all

Fig. 2. Study area within Cerrado biome (in gray-shaded Brazilian territory) and location of harvested buriti palm populations. Sampled populations are 1-Vazante, 2-Angelim, 3-Brejo do Antônio, 4-Brejo da Vaca, 5-Brejo do Velho, and 6-Ribeirão. The hydrographic network is represented because buriti palm swamp forests occur along watercourses in long, narrow swaths (10–50 meters wide).

Fig. 1. Handicraft made from Syngonanthus nitens scapes sewn with strips of Mauritiaflexuosa young leaves.

its area of occurrence (Heinen and Ruddle1974; Kahn1988; Lawrence et al.2005).

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We conducted 21 semistructured interviews in December 2005, and numerous open inter-views with harvesters and artisans of Mumbuca between August 2005 and August 2006, to gather information on buriti palms uses and harvesting. We asked interviewees about the time of the year, frequency, and preferences for harvesting sites and for palm individuals. We also asked about their perceptions of the con-servation status of buriti palm populations. Additionally, we observed several buriti palm-harvesting activities in the field.

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To evaluate the impact of young-leaf harvest-ing on individual palms, we randomly marked 60 young and immature individuals (see next section for life stage classification) in three study sites close (1–3.3 km, Table 1, Fig. 2) to the community (20 individuals per site). We selected these three sites due to the fact that buriti palm young leaves are intensively harvested there. Half the buriti palms marked in each site had no signs of leaf harvesting (hereafter called control individ-uals). Harvested individuals can be easy identified because the cut petiole remains attached to the plant many years after harvesting (Castro 2000; Joyal1995); this is the way harvesters in Jalapão check previous harvests in buriti palms. The other half of the buriti palms (here after called harvested individuals) had been previously harvested for leaves and had between 1 and 16 cut petioles (average=4.7; SE=0.58).

We measured the height of these 60 individ-uals, from the ground to the apex of the highest leaf, using an 11 m telescopic Crain® measuring rod, in August 2005 and August 2006, and then calculated the annual relative growth rate (RGR). We tagged all the leaves of these 60 palms and checked for newly-emerged leaves every four months between August 2005 and August 2006. The initial height did not differ between control and harvested individuals (t=0.05; n=60; p= 0.96, Table1).

We used ANCOVA to compare annual leaf production between control and harvested individu-als. In this analysis, we used the number of mature green leaves at the beginning of the study as a covariate, since it had a significant correlation with the annual leaf production rate (rs=0.45; p<0.001;

n=60). The number of buriti palm leaves harvested before the beginning of the study (rs=0.08; p=0.56;

n=60) and the initial height of the individual (rs=

0.04; p=0.78; n=60) were not significantly corre-lated with the annual leaf production rate; therefore, we did not use them as covariates.

We used ANOVA to compare the RGR of control and harvested buriti palms. We did not use covariates in this analysis because there was no correlation between the RGR and the number of leaves harvested at the beginning of the study (rs=− 0.02;

p=0.89; n=60), the initial plant height (rs=− 0.16;

p=0.23; n=60), or annual leaf production (rs=0.03;

p=0.85; n=60). Even after arcsine, logarithmic, and square-root transformations, some dependent variables showed no normality, according to the Shapiro-Wilk normality test (Zar 1999). Therefore, when necessary we used ranked data to perform the ANCOVA and ANOVAs, a procedure that can be employed as a nonparametric alternative (Tabachnick and Fidell 2001).

TABLE1. CHARACTERISTICS OF BURITI PALM POPULATION AND STUDY SITES IN THE JALAPÃO REGION, BRAZIL.

Vazante Angelim

Brejo do

Antônio Brejo da Vaca Brejo do Velho Ribeirão

Area (ha) 3.83 2.00 0.85 1.00 7.43 10.66

Linear distance (km) to Mumbuca 1.0 3.2 3.3 5.5 6.0 9.0

# Plots 20 19 15 20 23 23

Density of young (ind.ha−1) 320±94 253±93 347±109 220±68 164±49 157±90 Density of immature (ind.ha−1) 280±83 232±77 133±50 80±47 36±25 70±41 Density of reproductive (ind.ha−1) 300±76 421±65 667±127 460±88 564±88 609±106

% Young buriti palm harvested 19 25 31 9 0 0

% Immature buriti palm harvested 43 45 60 25 0 0

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In order to identify the effects of different harvesting intensities, we assessed buriti palm population structure in six sites within different distances from the community (1–9 km, Table1, Fig. 2), in August 2005. The closest three populations were the same ones used to assess the effects of harvest on leaf production and growth rates. We sampled buriti palm popula-tions using 5×5 meter plots randomly allocated in the swamp forest. The plots were at least 10 meters apart from each other, and the total number of plots per site (15–23) depended on the total area and shape of each swamp forest. We counted all buriti palms in the plots and classified them into five life stages [adapted from Cardoso et al. (2002)]: seedling up to 0.5 m tall; juvenile -0.5 m - 4 m tall; young - taller than 4 meters, but with petiole arising from the ground; immature -taller than 4 meters, with stem above ground level and not yet reproductive; reproductive - with stem above ground level and reproduction signs. For young and immature individuals - the stages that are subjected to young-leaf harvesting (see Results) - we counted the number of mature leaves and the number of young leaves harvested. We performed ANOVA followed by Tukey’s test to compare the density of each life stage among sites.

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We estimated fiber yield of young leaves by weighing the dry fiber obtained from 20 young leaves harvested by 12 artisans between March and August 2006. For each young leaf harvested, we recorded the buriti palm height, geographic coordinates, number of expanded mature green leaves, and number of leaves previously harvested. We measured with a tapeline the length and diameter of each young leaf and the maximum length of the strips obtained from it. We measured the dry weight of the strips with a Pesola® Präzisionswaagen spring-balance with 100 g capacity and 1 g precision. We assessed the association between the buriti palm’s biometric characteristics and the fiber production variables using Spearman’s rank correlation coefficient (rs).

Results and Discussion

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The Mumbuca community identified several uses of buriti palm parts. The pulp of fruit

collected from the ground is used as a food. Oil extracted from the seed is used to make soap and for cooking. A sweet nonfermented liquid extracted from the softest part of the stem from male individuals is known as buriti wine. The organic matter from the stem, after it decomposes on the ground, is used as a fertilizer. The bark is used to build fences. The mature leaves, harvested while they are green, are used for roofing and basket weaving. Their petioles (1.5–3 m long) are used for making doors, furniture, and toys. The fiber extracted from the young leaves is dried and used to sew golden grass handicrafts and to make cords and ropes. After thefiber is extracted, the rest of the young leaf is woven into mats, hammocks, and wall tapestries, as well as baskets (“tapeti”) used to squeeze out water from grated cassava during the production of cassava flour. These uses of buriti were reported in other studies, but a higher diversity of uses was reported by Mumbuca inhabitants as compared to communi-ties in the Amazon (Balick 1988; Castro 2000; Macia2004; Mejia1988; Rocha and Silva2005). Some of the buriti palm uses are decreasing due to the introduction of industrialized products. In contrast, the harvesting of young leaves for sewing golden grass handicrafts and the harvesting of petioles from green leaves to make furniture are both increasing. Among these extractive activities, the harvesting of young leaves for handicrafts has the greatest potential to impact buriti palm populations, since it is very frequent (see below) and its intensity is increasing. Thatching houses may also impact the buriti palm populations; however, in Jalapão, most houses are thatched with Attalea eichleri (Drude) A. J. Hend (Areca-ceae) leaves, and buriti leaves are used only to cover the roof ridge. The other harvesting practices are infrequent or non-intense.

Buriti palms produce one young leaf at a time, and the majority of harvesters claim that they never harvest two subsequent young leaves from the same palm as they believe that doing so can kill the palm. The young leaf is harvested by making a transversal cut through the petiole using a machete or sickle, without affecting the plant’s meristematic tissue. In Jalapão, young leaves are only harvested from young and immature buriti palms (4–10 meters tall and not reproductive), because smaller individuals have short fibers which are inadequate to sew golden grass handi-crafts, and because it is very difficult to climb

individuals that are taller than 10 m. Harvesters step on the petioles of mature leaves to climb the palm and reach the young leaf. Each artisan needs, on average, one young leaf per month to obtain sufficient fiber for handicrafting. Young leaves are harvested mainly from the swamp forests closest to the community, on average 1.8±0.2 (SE) km away from Mumbuca, where the harvesters usually go on foot. Young leaves are not harvested from sites more than 5.5 km away from the community (Table1, Fig.2). Harvest intensity is inversely related to the distance of the resource, as in other studied systems (Murali et al.1996; Uma Shaanker et al.2002).

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Young and immature buriti palms produce on average 2.82±0.11 (min.=1; max.=5; n=60) young leaves per year. This rate is similar to the one found for buriti seedlings (2.2–3.7 leaves per year) in a swamp forest in Venezuela (Ponce et al.

1999). However, 67% of harvesters believe that a buriti palm produces one leaf at every new moon, i.e., one new leaf per month, which is more than twice the maximum number of leaves a young buriti palm actually produces. This belief could lead to overexploitation, even by harvesters who do not intend to harvest consecutive leaves.

The intensity of leaf harvesting practiced by the artisans of Mumbuca did not influence the annual production rate of young leaves, since leaf production was similar between control and harvested individuals (F1.53=2.65; p=0.11). This

result was consistent across the three study sites, since there was no interaction between treatment (harvest and control) and site (F2.53=0.19; p=

0.83). However, there were significant differences among sites (F2.53=12.90; p<0.001): buriti palms

at the closest site to the community (Vazante, Table1) had a lower annual leaf production rate than the individuals from the other two sites (Tukey; p<0.001).

Leaf harvesting also did not affect buriti palm relative growth rate, which was similar between control and harvested plants (F1.54=0.10; p=0.76).

The RGR did not vary among sites (F2.54=1.08;

p=0.35), and there was no interaction between sites and treatment (F2.54=0.51; p=0.60). The

number of leaves previously harvested (1–16 leaves/palm) did not affect the annual leaf produc-tion rate (rs=0.15; n=30; p=0.43) and RGR (rs=

0.13; n=30; p=0.51) on harvested individuals.

All the 30 harvested individuals survived over the study period and our observations suggest that some individuals can successfully respond to young-leaf harvest and survive for longer periods. The individual exposed to the highest harvesting intensity (16 leaves previously harvested) had seven mature green leaves in the crown. Consid-ering the maximum leaf production rate (5 leaves/ year), this individual had been harvested for more than 4.6 years before the beginning of this study, and it survived and produced four leaves during the one-year period. On the other hand, artisans claim that some buriti palms can die due to overharvesting of young leaves, and we could identify some individuals producing smaller leaves probably due to overharvesting. These palms, locally called“shrunken,” tend to be found closer to communities or along paths. Reduction in leaf size due to harvesting has been reported for other palm species, including Chamaedorea radicalis Mart. (Endress et al. 2004) and Neodypsis decaryi Jum. (Ratsirarson et al. 1996).

The effects of leaf harvesting depend on the harvesting intensity and on the plant compensato-ry growth responses (Anten and Ackerly 2001). Additionally, plants exposed to more light have a higher capacity for compensatory responses (Anten et al.2003). In contrast to the palm Sabal uresana (Joyal1995), harvesting of young leaves apparently does not impact buriti palm individuals and populations. This might be explained by the fact that S. uresana occurs in deciduous forests, and its rates of leaf production are highly influenced by precipitation (Joyal 1995), whereas buriti palms occur in swamp forests with open canopy, without light restriction or water stress (Calbo et al.1998). Thus, buriti palms may have a higher resilience to leaf loss than S. uresana. However, when leaf removal is intense and frequent, the buriti palm reserves could be depleted, causing a decrease in new leaf size.

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All the buriti palm populations showed a “reverse J” structure, i.e., higher proportions of individuals in the early life stages than in late life stages in the six studied sites (Fig. 3). Non-harvested buriti palm population showed a similar structure in Minas Gerais state, Brazil (Cardoso et al. 2002). Reproductive buriti palms occurred in greater proportion than immature ones in all sites (Fig. 3). It is possible that immature individuals

remain in the prereproductive stage for a short time, and spend most of their lives as reproducers, as is the case for other long-lived species (Sampaio

2006; Zuidema and Boot2002).

Buriti palm density varied among sites (F= 3.02; p<0.001). The density of seedlings (F= 1.90; p=0.10), young (F=1.75; p=0.13), and reproductive individuals (F=1.21; p=0.31) was similar among sites. However, density of juveniles was higher in the three sites at intermediate distance from Mumbuca (Fig. 4a). This is probably due to environmental variation among sites rather than to fruit harvesting, since the density of seedlings - life stage most susceptible to fruit harvesting - was similar among sites. More-over, buriti palms produce fruits in abundance (Ponce Calderón 2002), and fruit harvesting generally has a low impact on palm populations (Bernal1998; Ratsirarson et al.1996).

The density of immature buriti palms tended to be higher in the two sites closer to Mumbuca (Fig.4b). This variation is also probably caused by environmental factors and not harvesting, since the highest density of immature palms was found in the sites subject to highest intensity of

leaf harvesting. More intense harvesting close to communities could potentially prevent immature individuals from growing and changing stages (Joyal1995); however, in our study, there was no difference in survival or growth rates between control and harvested individuals, at least over the one-year study period. Additionally, harvesters did not report any management actions to increase the densities of immature palms, even though it is a common practice with other NTFP (Muñiz-Miret et al. 1996; Trauernicht and Ticktin2005).

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Artisans prefer to harvest young leaves that produce higherfiber yields as well as longer and stronger fibers. The young leaves harvested had an average volume of 0.18±0.01 m3and produced dry fibers 1.55±0.03 m long, weighing 110.3± 9.53 g. The buriti palms chosen by the artisans for harvesting had on average 6.7±0.9 mature green leaves (min.=3, max.=15, n=20). Palm height did not influence the dry weight and length of the fibers obtained from their young leaves. In

Fig. 3. Proportion of individuals (on a logarithmic scale) in each life stage (seedling, juvenile, young, immature, and reproductive) for six buriti palm in Jalapão region, Brazil.

contrast, individuals with more mature green leaves produced wider and longer young leaves, which provided higherfiber yields (Table2).

Conclusions and Recommendations

This study was carried out over a one-year period only. However, it is important to point out that we

evaluated population structure, which reflects past and current mortality events (Watkinson 1997), and we also assessed the traditional knowledge associated with buriti palm young leaf harvesting, which has been accumulated over decades in the Mumbuca community. Our data suggests that the harvest of buriti leaves for handicrafts is possibly

Fig. 4. Average density of juvenile (A) and immature (B) buriti palms in the Vazante (Vaz), Angelim (Ang), Brejo do Antônio (Ant), Brejo da Vaca (Vac), Brejo do Velho (Vel), and Ribeirão (Rib) swamp forests in Jalapão region, Brazil. Different small letters indicate significant differences in buriti palm density between sites (p<0.05).

TABLE2. RELATIONSHIP BETWEEN BURITI PALM CHARACTERISTICS, YOUNG LEAF SIZE, AND FIBER PRODUCTION IN SITES CLOSE TO THE MUMBUCA COMMUNITY.

Buriti Palm Young-leaf Fibers

Height # Leaves # HL Length Diameter Volume Length Weight

Buriti palm Height –

# Leaves 0.65** – # HL −0.24ns _−0.27ns _– Young-leaf Length 0.48* 0.54* −0.26ns _– Diameter 0.30ns _{0.54* −0.27}ns _0.38ns _– Volume 0.52* 0.70*** −0.33ns 0.68*** 0.89*** – Fibers Length 0.21ns 0.18ns −0.20ns 0.72*** 0.27ns 0.44ns – Weight 0.44ns 0.52* −0.11ns 0.72*** 0.58* 0.74*** 0.45* – Values represent Spearman correlation coefficients (n=20). (*) p<0.05; (**) p<0.01; (***) p<0.001; HL = previously harvested leaves.

sustainable. Buriti palms are abundant, the popu-lation structure favors regeneration, and we did not detect any negative harvesting impacts on the populations or individuals. However, our field observations and harvesters’ knowledge indicate that buriti palms can be affected negatively by overexploitation. Therefore, until longer term ecological data are available, we recommend precautionary practices to avoid overexploitation. Artisans should harvest young leaves from buriti palms with more mature green leaves (ideally, more than six leaves), because they provide a greater yield of sewingfibers and have also higher annual leaf production rates. Harvesters should also harvest young leaves from swamp forests further away from the communities to avoid concentrating harvesting activities to only a few sites. This practice would be feasible because harvesters usually ride horses to distant areas in order to manage cattle, and buriti palm young leaves are not heavy to carry. These practices could help prevent harvest from having negative impacts on buriti palm populations over the long term. In order to disseminate information and practices that can foster ecological sustainability of buriti and golden grass handicrafts in Jalapão, the results and recommendations reported here are being dissemi-nated through talks and community meetings, and through the distribution of booklets and posters to schools, local associations, harvesters, artisans, other residents, and tourists in the Jalapão region.

Acknowledgments

Thanks to Juarez Amaral, Nilton Barbosa, and J.M. Rezende and to all Mumbuca residents, especially Ronaldo, Júnior, Martina, Adelcinei, Antônia, and Paizinho. Special thanks to Tamara Ticktin, Lisa Mandle, Jeff Boutain, Alexandre Sampaio, three reviewers, and Daniel Moerman for their suggestions on the manuscript. We also thank the Plant Conservation Laboratory at Embrapa-Cenargen and NATURATINS and the State Park of Jalapão for their support and for the PPP-ECOS ISPN/GEF/PNUD grant (project BRA/04/21).

Literature Cited

Anten, N. P. R. and D. D. Ackerly. 2001. Canopy-Level Photosynthetic Compensation after Defoliation in a Tropical Understorey Palm. Functional Ecology 152:252–262.

———, M. Martinez Ramos, and D. D. Ackerly. 2003. Defoliation and Growth in an Under-story Palm: Quantifying the Contributions of Compensatory Responses. Ecology 8411: 2905–2918.

Balick, M. J. 1979. Economic Botany of the Guahibo. I. Palmae. Economic Botany 334: 361–376.

———. 1988. The Use of Palms by the Apinayé and Guajajara Indians of Northeastern Brazil. Advances in Economic Botany 6:65–90. Bernal, R. 1998. Demography of the Vegetable

Ivory Palm Phytelephas seemannii in Colombia, and the Impact of Seed Harvesting. Journal of Applied Ecology 35:64–74.

Calbo, M. E. R., J. A. P. V. Moraes, and A. G. Calbo. 1998. Crescimento, Condutância Esto-mática, Fotossíntese e Porosidade do Buriti sob Inundação. Revista Brasileira de Fisiologia Vegetal 101:51–58.

Cardoso, G. L., G. M. Araújo, and S. A. Silva. 2002. Estrutura e Dinâmica de uma Popula-ção de Mauritia flexuosa (Arecaceae) em Vereda na Estação Ecológica do Panga, Uber-lândia, MG. Boletim do Herbário Ezequias Paulo Heringer 9:34–48.

Castro, A. 2000. Buriti (Mauritiaflexuosa). Pages 56–69 in J. W. Clay, P. T. B. Sampaio, and C. R. Clement, eds., Biodiversidade Amazôn-ica: Exemplos e Estratégias de Utilização. INPA, Manaus, Brazil.

Chabot, B. F. and D. J. Hicks. 1982. The Ecology of Leaf Life Spans. Annual Review of Ecology and Systematics 13:229–259. Endress, B. A., D. L. Gorchov, and M. B.

Peterson. 2004. Harvest of the Palm Chamae-dorea radicalis, Its Effects on Leaf Production, and Implications for Sustainable Management. Conservation Biology 183:822–830.

———, D. L. Gorchov, and E. J. Berry. 2006. Sustainability of a Non-Timber Forest Prod-uct: Effects of Alternative Leaf Harvest Prac-tices over Six Years on Yield and Demography of the Palm Chamaedorea radicalis. Forest Ecology and Management 2341–3:181–191. Heinen, H. D. and K. Ruddle. 1974. Ecology,

Ritual and Economic Organization in the Distribution of Palm Starch among the Warao of the Orinoco Delta. Journal of Anthropo-logical Research 302:116–138.

Henderson, A. 1995. The Palms of the Amazon. Cambridge University Press, New York.

———, G. Galeano, and R. Bernal. 1995. Field Guide to the Palms of the Americas. Princeton University Press, New Jersey.

Joyal, E. 1995. An Ethnoecology of Sabal uresana Trelease (Arecaceae) in Sonora, Mexico. Ph.D. Thesis, Arizona State University,

Kahn, F. 1988. Ecology of Economically Impor-tant Palms in Peruvian Amazonia. Advances in Economic Botany 6:42–49.

Kathriarachchi, H. S., K. U. Tennakoon, C. V. S. Gunatilleke, I. A. U. N. Gunatilleke, and P. M. S. Ashton. 2004. Ecology of Two Selected Liana Species of Utility Value in a Lowland Rain Forest of Sri Lanka: Implications for Management. Conservation and Society 22:273–288.

Klink, C. A. and R. B. Machado. 2005. Conservation of the Brazilian Cerrado. Con-servation Biology 193:707–713.

Lawrence, A., O. L. Phillips, A. R. Ismodes, M. Lopez, S. Rose, D. Wood, and A. J. Farfan. 2005. Local Values for Harvested Forest Plants in Madre de Dios, Peru: Towards a More Contextualized Interpretation of Quan-titative Ethnobotanical Data. Biodiversity and Conservation 14:45–79.

Macia, M. J. 2004. Multiplicity in Palm Uses by the Huaorani of Amazonian Ecuador. Botanical Journal of the Linnean Society 1442:149–159.

Mejia, K. 1988. Utilization of Palms in Eleven Mestizo Villages of the Peruvian Amazon (Ucayali River, Department of Loreto). Advances in Economic Botany 6:130–136. Muñiz-Miret, N., R. Vamos, M. Hiraoka, F.

Montagnini, and R. O. Mendelsohn. 1996. The Economic Value of Managing the Açaí Palm (Euterpe oleracea Mart.) in the Floodplains of the Amazon Estuary, Pará, Brazil. Forest Ecology and Management 871–3:163–173. Murali, K. S., U. Shankar, R. U. Shaanker, K. N.

Ganeshaiah, and K. S. Bawa. 1996. Extraction of Non-Timber Forest Products in the Forests of Biligiri Rangan Hills, India.2. Impact of NTFP Extraction on Regeneration, Popula-tion Structure, and Species ComposiPopula-tion. Economic Botany 503:252–269.

Myers, N., R. A. Mittermeier, C. G. Mittermeier, G. A. B. D. Fonseca, and J. Kent. 2000. Biodiversity Hotspots for Conservation Prior-ities. Nature 403:853–858.

Nepstad, D. C. and S. Schwartzman. 1992. Non-Timber Products from Tropical Forests: Eval-uation of a Conservation and Development Strategy. New York Botanical Garden, New York.

Panayatou, T. and P. S. Ashton. 1992. Not by Timber Alone: Economics and Ecology for Sustaining Tropical Forests. Island Press, Washington.

Peres, C. A., C. Baider, P. A. Zuidema, L. H. O. Wadt, K. A. Kainer, D. A. P. Gomes Silva, R. P. Salomao, L. L. Simoes, E. R. N. Franciosi, F. C. Valverde, R. Gribel, G. H. Shepard, M. Kanashiro, P. Coventry, D. W. Yu, A. R. Watkinson, and R. P. Freckleton. 2003. Demographic Threats to the Sustainability of Brazil Nut Exploitation. Science 302:2112– 2114.

Peters, C. M., A. Henderson, U. M. Maung, U. S. Lwin, U. T. M. Ohn, U. K. Lwin, and U. T. Shaung. 2007. The Rattan Trade of Northern Myanmar: Species, Supplies, and Sustainability. Economic Botany 611:3–13. Ponce Calderón, M. E. 2002. Patrones de Caída

de Frutos en Mauritia flexuosa L.f. y Fauna Involucrada en los Procesos de Remocíon de Semillas. Acta Botánica Venezuelica 252:167– 183.

Ponce, M. E., J. Brandin, M. A. Ponce, and V. Gonzales. 1999. Germinacion y Estableci-miento de Plantulas de Mauritia flexuosa L. F. (Arecaceae) en los Llanos Sur-Orientales del Estado Guarico, Venezuela. Acta Botânica Venezuelica 221:167–183.

Pott, V. J. and A. Pott. 2004. Buriti-Mauritia flexuosa. Fauna e Flora do Cerrado, Campo Grande, June 2004.

Ratsirarson, J., J. A. Silander, and A. F. Richard.] 1996. Conservation and Management of a Threatened Madagascar Palm Species, Neo-dypsis decaryi, Jumelle. Conservation Biology 101:40–52.

Ratter, J. A., J. F. Ribeiro, and S. Bridgewater. 1997. The Brazilian Cerrado Vegetation and Threats to Its Biodiversity. Annals of Botany 803:223–230.

Rocha, A. E. S. D. and M. F. F. D. Silva. 2005. Aspectos Fitossociológicos, Florísticos e Etno-botânicos das Palmeiras (Arecaceae) de Floresta Secundária no Município de Bragança, PA, Brasil. Acta Botânica Brasílica 193:657–667.

Runk, J. V., P. Mepaquito and F. Peña. 2004. Artisanal Non-Timber Forest Products in Darién Province, Panamá: The Importance of Context. Conservation and Society 22:217–234.

Sampaio, M. B. 2006. Ecologia Populacional da Palmeira Geonoma schottiana Mart. em Mata de Galeria no Brasil Central. M.Sc. Thesis, Depart-ment of Ecology, University of Brasilia, Brazil. Schmidt, I. B., I. B. Figueiredo, and A. Scariot.

2007. Ethnobotany and Effects of Harvesting on the Population Ecology of Syngonanthus nitens (Bong.) Ruhland (Eriocaulaceae), a NTFP from Jalapão Region, Central Brazil. Economic Botany 611:73–85.

Seplan. 2003. Zoneamento Ecológico Econômico do Tocantins. Seplan, http://www.zeeppa.

cnpm.embrapa.br/ppa/toca.html. Accessed

September 09, 2007.

Svenning, J. C. and M. J. Macia. 2002. Harvesting of Geonoma macrostachys Mart. Leaves for Thatch: An Exploration of Sustainability. For-est Ecology and Management 167:251–262. Tabachnick, B. G. and L. S. Fidell. 2001. Using

Multivariate Statistics. Allyn and Bacon, Boston. Ticktin, T. 2005. Applying a Metapopulation Framework to the Management and

Conser-vation of a Non-Timber Forest Species. Forest Ecology and Management 2061–3:249–261. Trauernicht, C. and T. Ticktin. 2005. The

Effects of Non-Timber Forest Product Culti-vation on the Plant Community Structure and Composition of a Humid Tropical Forest in Southern Mexico. Forest Ecology and Man-agement 2192–3:269–278.

Uma Shaanker, R., K. N. Ganeshaiah, M. Nageswara Rao, and N. A. Aravind. 2002. Ecological Consequences of Forest Use: From Genes to Ecosystem. A Case Study in the Iiligiri Rangaswamy Temple Wildlife Sanctu-ary, South India. Conservation and Society 22:347–363.

Watkinson, A. R. 1997. Plant population dy-namics. In M. J. Crawley, ed., Plant popula-tion dynamics. Blackwell Science, Oxford. Zar, J. H. 1999. Biostatistical Analysis.

Prentice-Hall, New Jersey.

Zuidema, P. A. and R. G. A. Boot. 2002. Demography of the Brazil Nut Tree (Berthol-letia excelsa) in the Bolivian Amazon: Impact of Seed Extraction on Recruitment and Pop-ulation Dynamics. Journal of Tropical Ecology 18:1–31.