Identifying target species and seed sources for the restoration of threatened trees in southern Brazil P. M. HOFFMANN,C.T.BLUM,S.J.E.VELAZCO,D.J.C.GILL and M . B ORGO Abstract Ecological restoration of trees is often constrained Targets have been set to restore % of degraded land by by limited knowledge of the biology, propagation and man- (CBD, ) but restoration efforts are often con- agement requirements of individual species. Consequently, strained by lack of knowledge of the biology, propagation restoration initiatives rarely incorporate less well-known and management of tree species or by a lack of sufficient species or those that are difficult to source and grow. We de- seed (Merritt & Dixon, ). A reliable source of high- scribe challenges associated with the restoration of threa- quality seed is critical to the success of restoration projects, tened trees in the Araucaria Forest of southern Brazil, and directly influencing the germination and survival of seed- analyse the effectiveness of methods used to define target lings and the genetic diversity of populations (Zahawi & species, identify seed sources and generate information on Holl, ). the phenology of rare or threatened tree species. A review These challenges are particularly pertinent to the of secondary data identified rare or threatened taxa as tar- Brazilian Atlantic Rainforest, a biodiversity hotspot gets for seed collection. We then surveyed . km of trails (Myers et al., ) with ., plant species and , in forest remnants, identifying and mapping , seed- animal species interacting across multiple trophic levels producing trees of species. Surveys confirmed the scarcity (Mittermeier et al., ; Ribeiro et al., ). Less than of several tree species (including seven species with an abun- % of the forest remains, in isolated remnants, many of dance of ,. individuals per km), and nine species which are highly degraded (Ribeiro et al., ). Attempts showed no signs of fruiting during years of phenological to restore the biome have evolved from projects focusing monitoring. These findings, together with limited knowl- on a small number of fast-growing species (most of which edge and application of optimal seed collection methods, failed to establish into self-perpetuating forest; Barbosa are significant factors impeding the recovery of these species et al., ) to initiatives adopting a high-diversity planting within their natural habitat. Wider application of the results approach (e.g. planting – tree species; Rodrigues et al., of this case study could support restoration of the Araucaria ). For many tree species, however, a lack of information Forest with seedlings from a wider diversity of species. on their reproductive biology prevents their inclusion in res- toration projects (Rodrigues et al., ). Keywords Araucaria Forest, Brazil, conservation, phe- The Araucaria Forest is one of the most threatened eco- nology, propagation, seed collection, subtropical forest res- systems in the Atlantic Rainforest biome. In Paraná state, toration, threatened species where Araucaria Forest was once the dominant vegetation This paper contains supplementary material that can be type, covering ,, ha (Maack, ), ,.% of the orig- found online at http://journals.cambridge.org 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 Introduction naturally occurring species (Liebsch et al., ). Restoration is the main mechanism available to restore he restoration of damaged but previously complex eco- species richness in the Araucaria Forest, but seed collection Tsystems may be one of the greatest challenges facing and tree planting tend to be focused on a narrow range of tropical forest conservation (Rojas-Briales & Weise, ). 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, P. M. HOFFMANN (Corresponding author), S. J. E. VELAZCO and M. BORGO Sociedade Chauá, 82130-010, Curitiba, Brazil. E-mail [email protected] which are the main producers of seedlings for restoration of this ecosystem (Martins et al., ). It is common practice C. T. BLUM Departamento de Ciências Florestais, Universidade Federal do Paraná, Curitiba, Brazil to produce seedlings of species that are easy to collect, D. J. C. GILL Fauna & Flora International, Cambridge, UK fast-growing or technically simple to grow, rather than Received June . Revision requested August . many native species for which there is a lack of information Accepted November . on seed collection and germination protocols. Only %of © 2015 Fauna & Flora International, Oryx, Page 1 of 6 doi:10.1017/S0030605314001069 http://journals.cambridge.org Downloaded: 18 Mar 2015 IP address: 205.243.145.122 2 P. M. Hoffmann et al. ). Mean annual temperature is –°C and annual pre- cipitation is ,–, mm (IAPAR, ). This subtropi- cal forest is characterized by a dense physiognomy, marked by the dominance of emergent Araucaria angustifolia trees, with a mean height of – m (Scheer & Blum, ). Methods A list of target species for seed collection was identified, in- cluding all threatened or rare tree species. Threatened spe- cies were defined as those listed in the regional, national or global Red Lists (SEMA, ; MMA, ; IUCN, ), in- cluding species categorized as Near Threatened. The threat categories of the various Red Lists were standardized ac- cording to IUCN (). Rare species were defined as those not included in official Red Lists but with few her- barium records (INCT, ) and a low frequency of occur- rence, identified through surveys of the structure of the FIG. 1 Original distribution of Araucaria Forest in Paraná, Brazil Araucaria Forest (Durigan, ; Pasdiora, ; Barddal (adapted from Olson et al., ). The rectangle on the inset et al., ; Geraldi et al., ; Seger et al., ; indicates the location of the main map in Brazil. Watzlawick et al., ; Kozera et al., ; Cordeiro & Rodrigues, ; Cordeiro, ). the threatened species of the Araucaria Forest have been A list of potential forest remnants was developed based grown by state nurseries (Martins et al., ). In cases on the occurrence of at least one target species. Data on where nurseries produce seedlings of threatened species, the conservation status of these remnants were compiled seeds are usually collected from a small number of trees, re- based on our knowledge and on a technical report of the sta- sulting in low genetic variability and fitness of seedlings tus of the Araucaria Forest (Castella & Britez, ). (Zahawi & Holl, ). The final selection was based on geographical variability Fast-growing species play an important role in the resto- (including various floristic associations within the ration process. By developing a canopy layer and encourag- Araucaria Forest, to maximize genetic variability for each ing the return of seed dispersers and pollinators they can species), forest condition (fragments of medium to ad- accelerate forest succession and the natural recruitment of vanced successional stage, with a minimum size of a wide range of species (Elliott et al., ). However, in de- ha), and guarantee of protection (remnants located in pro- graded and fragmented landscapes, such as the Araucaria tected areas or under other forms of conservation manage- Forest, restoration with a low diversity of species is unlikely ment, thus maximizing the likelihood of selected mother to create the conditions necessary for dispersal of a wider trees surviving and being available for long-term monitor- range of naturally occurring species (Rodrigues et al., ing and seed collection). ). There is therefore a growing need for government Each selected forest remnant was surveyed intensively by agencies and conservation institutions to broaden the walking along all existing trails to search for mother trees of focus of seed collection and restoration efforts to include target species. Species were initially identified in the field threatened or locally rare species as well as fast-growing spe- and later confirmed by comparison with herbarium spe- cies. Here we present a list of target species for conservation cimens. The criteria for selection of mother trees were and restoration, identify sources of seeds (mother trees), es- good health (free of damage, disease and infestation by in- timate their frequency and abundance, and present basic in- sects) and full reproductive maturity (tree size, presence of formation about phenological patterns of threatened and old fruits, seeds or seedlings under the tree). rare species in the Araucaria Forest. We attempted to map the highest number of mother trees in the maximum possible number of remnants. To ob- Study area tain seeds with broad genetic variation, they were collected, when possible, from at least three populations of each spe- The Araucaria Forest once covered the plateau regions in the cies (Nogueira & Medeiros, ), and from at least trees centre and south of Paraná, at –, m altitude (Fig. ). per population (Vencovsky, ). When this was not poss- The climate is humid subtropical, with cool summers and ible, surveys aimed to identify at least trees per species in no dry season; frost is common in winter (Peel et al., the whole study area. Closely related individuals of the same © 2015 Fauna & Flora International, Oryx,1–6 http://journals.cambridge.org Downloaded: 18