Research AbstractA critical evaluation of two quantitative techniques used in ethnobotanical studies was undertaken using data concerning plant use in a rural community in the semi-arid region of Pernambuco State, northeastern Brazil. The relative importance of 36 native woody species reported as being useful by 98 informants was calculated employing the Use-Value (UV) and Relative Importance (RI) techniques. Both techniques place value on a given taxon based on the number of uses attributed to it. Results obtained for both techniques are positively correlated, suggesting that they can be used interchangeably to evaluate local knowledge of a given resource. The implications and interpretation limitations of these two techniques are discussed in detail.

RESUMO -(Contribuição de quintais agroflorestais na conservação de plantas da Caatinga, Município de Caruaru, PE, Brasil). A presente pesquisa foi realizada na zona rural do município de Caruaru, tendo como objetivo estudar a diversidade florística e a contribuição de quintais agroflorestais para a conservação da diversidade local. O trabalho foi conduzido a partir de entrevistas semi-estruturadas, associadas à técnica da turnê-guiada, realizada com os mantenedores dos quintais. Paralelamente, fez-se medição da área do quintal e de todos os indivíduos lenhosos com DNS (diâmetro ao nível do solo) ≥ 3 cm. Registrou-se 25 quintais, nos quais foram relacionadas 84 espécies, pertencentes a 68 gêneros e 35 famílias, destacando-se as famílias Euphorbiaceae (10 spp.), Anacardiaceae (7 spp.), Caesalpiniaceae (6 spp.), Mimosaceae (6 spp.) e Myrtaceae (6 spp.). As espécies introduzidas (55 espécies) dominaram nos sistemas em relação às nativas. Apesar destas terem sido menos freqüentes nos quintais agroflorestais, elas são importantes para conservação da diversidade local devido, principalmente, ao uso madeireiro, o que poderia implicar na redução do impacto na vegetação local. Este dado é um indicativo de que por meio de um plano de manejo adequado, os quintais agroflorestais constituem uma alternativa, de baixo custo, para a conservação da diversidade local.Palavras-chave: sistemas agroflorestais, etnobotânica, conservação da biodiversidade, florestas secas, plantas alimentícias, plantas medicinais ABSTRACT -(Contribution of homegardens to the conservation of caatinga plants, Municipality of Caruaru, Pernambuco State, Brazil). The research presented here was undertaken in a rural area within the municipality of Caruaru. It was designed to evaluate the floristic diversity of homegardens and their role in conserving local diversity. Semi-structured interviews with the people responsible for these plots were carried out, in association with the technique of guided excursions. The sizes of the homegardens were measured, and all woody plants with a DGL (Diameter at Ground Level) ≥ 3 cm were recorded. A total of 25 plots were examined, containing 84 species of plants, belonging to 68 genera and 35 families. The most species rich families were Euphorbiaceae (10 species), Anacardiaceae (7), Caesalpiniaceae (6), Mimosaceae (6), and Myrtaceae (6). Introduced species (55 species) were most prevalent. Eventhough native species were less frequent than introduced species in these homegardens, these plots are important for the conservation of local diversity, principally because of the protection they provide to local woody species by reducing the impact of tree harvesting. This information indicates that, when properly managed, homegardens represent a low-cost alternative for conserving local diversity.

The use of native plants was examined in three rural communities in the semi-arid of the state of Pernambuco, in northeastern Brazil. The techniques employed in the present study combined a number of different techniques of data-gathering, including semi-structured interviews, guided tour, key-informants, and participating observation, and sampling of the vegetation to evaluate the biodiversity of useful plants. A total of 61 woody species were cataloged, mostly used for construction purposes or fuel. Among the species that stood out for their local importance and multiplicity of uses were: Myracrodruon urundeuva (Engl.) Fr. All., Schinopsis brasiliensis Engl., and Anadenanthera colubrina (Vell.) Brenan. The first two species are included in Brazilian lists of threatened species. Arguments are presented for strategies of management and conservation of plant resources in the semi-arid region that seek alternatives to the use of timber species and the development of alternative non-timber resources.

The use and management of "angico" (Anadenanthera colubrina (Vell.) Brenan) by a rural community in northeastern Brazil was examined. By employing different techniques of data collection and population structure analysis, it was determined that this species had multiple uses within the local community (especially as timber and for other wood products), and that local management of this species is based on simple maintenance and harvesting of individuals in agroforest homegardens. The study of the population structure of this tree species indicated that management and conservation strategies must include the participation of the local community.