Nivaldo Peroni

Current and lost diversity of cultivated varieties, especially cassava, under swidden cultivation systems in the Brazilian Atlantic Forest

Tropical agricultural systems characterized by swidden-fallow practices have been studied in many tropical areas of the world. One feature of these systems is the high diversity of cultivated species and varieties. The objective of this paper was to analyze the inter and intraspecific diversity of cultivated crops under swidden cultivation systems adopted by caicaras in the Brazilian Atlantic Forest, and the genetic erosion of this diversity in the last decades. To analyze the inter and intraspecific diversity of cultivated crops under swidden cultivation systems in the Brazilian Atlantic Forest, interviews were performed in 33 swidden agriculturists’ households concerning the species and varieties under cultivation and others that have been lost. The plots were visited to check the crops cited in the interviews. The agriculturists cited 261 varieties from 53 crop species, with 30.6% of lost varieties. Each agriculturist cited an average of 25 varieties. The main crop was cassava ( Manihot esculenta Crantz), followed by yams (Dioscorea spp.), sweet potato (Ipomoea batatas Poir.), squash (Cucurbita pepo L.), sugarcane (Saccharum officinarumL.), and beans (Phaseolus vulgarisL.). Among the interviewed agriculturists, 87% of them have sons and/or daughters not involved in agricultural activity, reflecting a trend toward the loss of the local agricultural skills. A model was proposed to explain the dynamics of the system focusing on the crop diversity and considering the resource resilience. The exchange of crop varieties among agriculturists builds a network which buffers against the loss of the managed diversity in the regional scale. Features such as the itinerancy cycles of fallow/swidden, and the traditional ecological knowledge contribute to the increasing of the managed diversity. However, the agriculturists also pointed out several factors contributing to the depletion of the managed diversity, related to restrictive environmental laws, rural exodus, increasing tourism, and changing of livelihood activities. The loss of crop diversity indicates the urgency for strategies towards the maintenance of the diversity and knowledge tied to the agricultural systems of caicara communities, calling for specific strategies and policies to avoid the loss of their agricultural legacy.

Genetic diversity in Brazilian sweet potato (Ipomoea batatas (L.) Lam., Solanales, Convolvulaceae) landraces assessed with microsatellite markers

We used simple sequence repeat (SSR) markers to investigate the genetic diversity of 78 sweet potato (Ipomoea batatas) accessions (58 landraces and 20 putative clones) from traditional agricultural households from 19 local communities in the Vale do Ribeira, Sao Paulo, Brazil. Eight SSR loci were assessed using 6% (w/v) polyacrylamide gels stained with silver nitrate and the accessions genotyped considering the presence or absence of bands. The results were subjected to analysis of molecular variance (AMOVA), and cluster and principal coordinate analyses. Spatial structure was assessed using Mantels test to compare genetic and geographic distances. Each primer pair generated between three and ten clearly scorable polymorphic fragments. Cluster analyses showed a Jaccards index from 0.3 to 1.0, indicating high genetic and intravarietal diversity. Accessions from all 19 communities were not spatially structured (r = 0.15, p < 0.054), with AMOVA indicating that most of the variability (58.2%) was distributed within households and only 18.1% of the variability was distributed between households within communities. The outcrossing mating system of sweet potato, and anthropic factors such as selection of different varieties and their maintenance within household small plots and home gardens, as well as an extensive exchange system between agriculturists, may all be contributing to these results.

Knowledge and Use of Biodiversity in Brazilian Hot Spots

Hot spots in Brazil include a variety of ecosystems, such as mangroves, forests, and the Brazilian savannah, locally called cerrado. Some of the rural populations in these hot spots are the caiçaras in SE Atlantic Forest coast, and the caboclos in the Amazon. In this study, we are concerned especially with the knowledge of caiçaras and caboclos, associated with practices that might have implications for management. Data were gathered through interviews with adults at the various communities studied, and through systematic observations, including samples of fishing trips and the mapping of fishing spots used in the Atlantic Forest coast. The use of resources from the surrounding vegetation includes collection of plants, cultivated fruit gardens, the swidden system, and a careful and managed extraction of fibres. Among animal resources, food taboos seem to be useful practices that might contribute to the maintenance of local natural resources. Potential management practices should be locally developed, such as the informal division of fishing spots in Atlantic Forest sites, and the maintenance of the diversity of cassava varieties in both the Atlantic Forest and Amazonian areas.

Between the sea and the land: the livelihood of estuarine people in southeastern Brazil

The central focus of this study is to characterize and compare the livelihood strategies of two coastal communities from the estuarine region of Ribeira Valley (Sao Paulo State, Southeastern Brazil), analyzing the interplay among four economic activities: small-scale agriculture, fishing, tourism-related jobs, and extraction of non-timber vegetal resources. The local people of these communities are mostly Caicara, the native inhabitants of southeastern Brazilian coast, in an Atlantic forest area. The miscegenation of Amerindians, European colonizers, and African Brazilians gave rise to the Caicara people, whose subsistence was originally based on small-scale itinerant agriculture, small-scale fishery, and some extraction of forest products. Their livelihoods activities changed through time: agricultural practices were gradually abandoned, while fishing grew in importance. Recently, tourism-related jobs and the extraction of non-timber vegetal resources acquired a key role in the estuarine Caicara livelihood. After an historical overview, we focus our analysis on the local factors and external pressures affecting the combination of these activities.

Phenology and morphological diversity of sweet potato (Ipomoea batatas) landraces of the Vale do Ribeira

The phenotypic diversity of sweet potato (Ipomoea batatas) landraces was assessed using morphological traits, verifying how this diversity is distributed among the households and settlements of the Vale do Ribeira, Brazil. A total of 74 accessions, involving 53 landraces, collected from 30 households distributed among 18 settlements that practice traditional agriculture in the municipalities of Iguape, Ilha Comprida, and Cananeia, as well as four commercial varieties acquired in markets of Iguape and Piracicaba, were evaluated under an ex situ experimental condition in Piracicaba, SP, Brazil. Nine phenological and floral descriptors, nine morphological vegetative aerial descriptors and five storage root traits were recorded. The 14 aerial vegetative and root descriptors were evaluated as binary data, totaling 74 attributes. Cluster analyses were made using the Jaccard similarity index and the UPGMA (unweighted pair group method with arithmetic mean) agglomerative method. Binary data was also submitted to a variance analysis (AMOVA). No defined groups were observed, indicating that the diversity of the landraces is not structured in space, but considerable morphological variation was found in this area (Jaccard similarity index varying from 0.12 to 1.0). Most of the variability occurred within households (64.4%), followed by the distribution among households within settlements (27.1%) and among settlements (8.4%). Thus, the traditional agriculturists of Vale do Ribeira maintain a high morphological diversity for sweet potato within their households, which can be assumed to be produced by the outcrossing mating system of this species and somatic mutation events, as well as the exchange system at local and regional levels.

Diversidade inter- e intra-específica e uso de análise multivariada para morfologia da mandioca (Manihot esculenta Crantz): um estudo de caso

Shifting cultivation, or slash-and-burn agriculture, is a technique used by many farmers all over the world and also by traditional farmers of Cananeia (SP). These farmers have inherited a set of skills and knowledges, orally transferred through generations, about the agriculture carried out by indigenous people, since Brazils pre-colonialist period. Cassava (Manihot esculenta Crantz) is the main crop in this system, representing a key crop for the understanding of the specificities of the shifting cultivation. Information about the crop species and ethnovarieties was obtained. Interviews with the farmers allowed to characterize the system used in the region, showing that 62 ethnovarieties of 15 different species were cultivated in the studied propriety, reflecting the high inter- and intraspecific diversity. Principal component analysis (PCA) and cluster analysis were used to characterize cassava samples. Through the evaluation of 21 morphological characters in one traditional farmers field, it was possible gather cassava ethnovarieties in groups coherent with the local classification. The employed methodology seems to be very efficient with data gathered in non-experimental conditions.

Gender Influences in the Perception and Use of the Landscape in a Rural Community of German Immigrant Descendants in Brazil

People interact with the landscape and use its resources on a daily basis. An ecotope is the smallest ecological place culturally recognized within a landscape. Many ecotopes reveal the interaction between local communities and the environment and perceptions about ecotopes are based on the experiences of their observers. We studied local perceptions of ecotopes recognized by rural men and women, in order to understand the decision-making processes related to ecotope management and the use of plant resources in these landscapes. The study area was in Ribeirão Taquaras (Ibirama municipality, Santa Catarina, Brazil), a region populated with descendants of German immigrants. Through 91 interviews (41 men and 50 women) and four participatory workshops, two with women and two with men, we identified 12 ecotopes. The interaction between people and the environment determines their knowledge about plant resources and the environment and this varies according to their social roles. These interactions occur with cultivated and harvested plant resources and in ecotopes under different intensities of management. The perception of the environment reflects this interaction, social roles and relationships, and the historical context reflected in the environment. The different perceptions of men and women reveal features and complementarities in decision-making and daily tasks on rural properties.