Identifying target species and seed sources for the restoration of threatened trees in southern Brazil P. M. H OFFMANN , C. T. B LUM , S. J. E. V ELAZCO , D. J. C. G ILL and M . B ORGO Abstract Ecological restoration of trees is often constrained by limited knowledge of the biology, propagation and man- agement requirements of individual species. Consequently, restoration initiatives rarely incorporate less well-known species or those that are difficult to source and grow. We de- scribe challenges associated with the restoration of threa- tened trees in the Araucaria Forest of southern Brazil, and analyse the effectiveness of methods used to define target species, identify seed sources and generate information on the phenology of rare or threatened tree species. A review of secondary data identified  rare or threatened taxa as tar- gets for seed collection. We then surveyed .km of trails in  forest remnants, identifying and mapping , seed- producing trees of  species. Surveys confirmed the scarcity of several tree species (including seven species with an abun- dance of ,. individuals per km), and nine species showed no signs of fruiting during years of phenological monitoring. These findings, together with limited knowl- edge and application of optimal seed collection methods, are significant factors impeding the recovery of these species within their natural habitat. Wider application of the results of this case study could support restoration of the Araucaria Forest with seedlings from a wider diversity of species. Keywords Araucaria Forest, Brazil, conservation, phe- nology, propagation, seed collection, subtropical forest res- toration, threatened species This paper contains supplementary material that can be found online at http://journals.cambridge.org Introduction T he restoration of damaged but previously complex eco- systems may be one of the greatest challenges facing tropical forest conservation (Rojas-Briales & Weise, ). Targets have been set to restore % of degraded land by  (CBD, ) but restoration efforts are often con- strained by lack of knowledge of the biology, propagation and management of tree species or by a lack of sufficient seed (Merritt & Dixon, ). A reliable source of high- quality seed is critical to the success of restoration projects, directly influencing the germination and survival of seed- lings and the genetic diversity of populations (Zahawi & Holl, ). These challenges are particularly pertinent to the Brazilian Atlantic Rainforest, a biodiversity hotspot (Myers et al., ) with ., plant species and , animal species interacting across multiple trophic levels (Mittermeier et al., ; Ribeiro et al., ). Less than % of the forest remains, in isolated remnants, many of which are highly degraded (Ribeiro et al., ). Attempts to restore the biome have evolved from projects focusing on a small number of fast-growing species (most of which failed to establish into self-perpetuating forest; Barbosa et al., ) to initiatives adopting a high-diversity planting approach (e.g. planting  tree species; Rodrigues et al., ). For many tree species, however, a lack of information on their reproductive biology prevents their inclusion in res- toration projects (Rodrigues et al., ). The Araucaria Forest is one of the most threatened eco- systems in the Atlantic Rainforest biome. In Paraná state, where Araucaria Forest was once the dominant vegetation type, covering ,, ha (Maack, ), ,.% of the orig- inal forest remains in advanced successional stages, none of which is considered primary forest (Castella & Britez, ). Such extensive fragmentation means that areas left to regen- erate without human assistance never attain the full range of naturally occurring species (Liebsch et al., ). Restoration is the main mechanism available to restore species richness in the Araucaria Forest, but seed collection and tree planting tend to be focused on a narrow range of species. Partly as a result of low seed collection effort, only  of the  tree species found in Araucaria Forest (Leite & Klein, ) have been cultivated by Paraná state nurseries, which are the main producers of seedlings for restoration of this ecosystem (Martins et al., ). It is common practice to produce seedlings of species that are easy to collect, fast-growing or technically simple to grow, rather than many native species for which there is a lack of information on seed collection and germination protocols. Only % of the threatened species of the Araucaria Forest have been grown by state nurseries (Martins et al., ). In cases P. M. HOFFMANN (Corresponding author), S. J. E. VELAZCO and M. BORGO Sociedade Chauá, 82130-010, Curitiba, Brazil. E-mail pblhffmnn@gmail.com C. T. BLUM Departamento de Ciências Florestais, Universidade Federal do Paraná, Curitiba, Brazil D. J. C. GILL Fauna & Flora International, Cambridge, UK Received  June . Revision requested August . Accepted  November . First published online  March . Oryx, 2015, 49(3), 425430 © 2015 Fauna & Flora International doi:10.1017/S0030605314001069 https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0030605314001069 Downloaded from https://www.cambridge.org/core. IP address: 34.228.24.229, on 11 Jun 2020 at 00:45:50, subject to the Cambridge Core terms of use, available at