Araucaria forest is a sub-tropical component of the Atlantic Forest Biome, occurring between 18 and 30 • S latitude, and 500-1,800 m altitude in Southern and Southwestern Brazil and Northwestern Argentina. In recent history (Twentieth century), this forest has undergone non-sustainable exploitation and reduction in area dedicated to agricultural and forestry use. However, smallholders continue using several resources from this forest, even adapting management systems. The main system is geared toward the production of yerba mate (Ilex paraguariensis) under araucaria trees (Araucaria angustifolia), which holds economic, cultural, and social relevance for thousands of farmers. Seeking evidence of domestication and conservation of the resources managed in this system, we compared different landscapes on the Northern Plateau of Santa Catarina in Southern Brazil. Focusing on three species-yerba mate, araucaria and caraguatá (Bromelia antiacantha)-we characterized management practices (interviews and guided tours), demographic structure (permanent plots in farming zones and in a protected area), and genetic diversity in populations from the same places. Demographic structure and genetic diversity from different landscapes were compared to evaluate the system potential for conservation. The results indicated that the three species are intentionally promoted with practices of protection, transplanting and/or selection, in different ways and with different functions (caraguatá hedges, yerba mate harvesting, and collection of pinhões-seed like nuts-of araucaria). Landscapes are managed for yerba mate harvesting and cattle raising, for both economic and cultural reasons, with a consequent reduction in the density of most other plant species. In all cases the genetic diversity of the species was high for most of the sampled properties, and the set of farmers' populations did not differ from the protected area. The set of populations of each species operates as a metapopulation and local management practices contribute to conservation. Thus, the farmers' management systems and practices maintain the Reis et al.Conservation-by-Use System in Araucaria Forests landscape with productive forest fragments, favoring the conservation-by-use of these species. The system requires these management practices, which bring about changes in various species and are motivated by cultural and economic factors, in order to maintain the landscapes domesticated.

Dyckia ibiramensis is a naturally rare, endemic and threatened bromeliad which occurs naturally on 4 km of rocky river outcroppings in Southern Brazil. For this study, subpopulations of the species were characterized based on size and genetics, to compile information for in situ and ex situ conservation strategies. A census of the rosettes was undertaken for each subpopulation and seven allozyme polymorphic loci were used to estimate genetic diversity and structure of adults and offspring and assess the mating system. In general, the subpopulations were small and most of the rosettes were aggregated into clumps. The species showed a high genetic diversity (Ĥ e ¼ 0:219) and significant fixation index (f ¼ 0:642; P B 0.05). The estimate of differentiation among all adult subpopulations indicate pronounced genetic structure (Ĝ 0 ST ¼ 0:674). D. ibiramensis has a mixed mating system and multilocus outcrossing ratest m were variable between subpopulations. This study demonstrates the importance of in situ preservation of all subpopulations for the maintenance of species diversity. For effective ex situ conservation, it would be necessary to collect seeds from 52 to 99 seed-rosettes, depending on the target population.

Varronia curassavica, a subshrubby medicinal species associated with restinga in the Atlantic Forest, has been exploited by local people and the pharmaceutical industry. Indeed, restingas have experienced a continuous process of degradation, and thus, with species and ecosystem both at risk, efforts to support conservation actions are required. The present study aimed to evaluate aspects of V. curassavica reproductive biology. To accomplish this, morphological characterization was performed by monitoring flowering events. The availability of nectar and pollen, as well as the frequency and behavior of floral visitors and dispersers, was also evaluated. This species exhibits both heterostyly and protogyny. Anthesis is diurnal, and flowers last less than a day. The high number of flower and fruit abortions suggests that mechanisms, such as self-incompatibility intra-morphs and easily detached flowers, contribute to reduced fruit production. The high diversity of floral visitors indicate a generalist pollination syndrome. Diptera, Hymenoptera and Lepidoptera were the main pollinators, and nectar was the main resource sought by these insects. Fruits were dispersed by birds and ants. It can be concluded that the interaction of V. curassavica with several species is a key factor in its own survival and for maintaining the biological diversity of restinga.

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