The Cerrado (Brazilian savanna) is a biodiversity hotspot with a history of fire that goes back as far as 10 million years. Fire has influenced the evolution of several aspects of the vegetation, including reproduction and life cycles. This study tested how fire by‐products such as heat and smoke affect the germination of six species common to two Cerrado open physiognomies: wet grasslands and the campo sujo (grassland with scattered shrubs and dwarf trees). We subjected seeds collected in northern Brazil to heat shock and smoke treatments, both separately and combined, using different temperatures, exposure times, and smoke concentrations in aqueous solutions. High temperatures and smoke did not break seed dormancy nor stimulate germination of the Cerrado study species. However, seeds were not killed by high temperatures, indicating that they are fire‐tolerant. Our findings differed from those of other fire‐prone ecosystems (mostly of Mediterranean vegetation), where fire stimulates germination. Moreover, we provide important information regarding germination strategies of non‐woody Cerrado plants, showing the importance of considering the tolerance of seeds to high temperatures when evaluating fire‐related traits in fire‐prone ecosystems.

ABSTRACT(Eff ects of high temperatures on the germination of Syngonanthus nitens seeds: implications for management. Th is study aimed to assess the eff ects of fi re on germination of golden-grass (Syngonanthus nitens (Bong.) Ruhland, Eriocaulaceae) seeds. Seeds collected in Jalapão (Tocantins, Brazil) were exposed to heat shock treatments at 60 °C, 100 °C, 150 °C and 200 °C, for 1' , 3' , and 5' . For each treatment and control fi ve replications were used (20 seeds each). Seeds were put on Petri dishes and placed inside germination chambers set at 28 °C, 12h/12h, for 40 days. Germination rates were analyzed by two-factorial ANOVA, using randomization tests. Most treatments showed high germination rates (>85%), except for 200°C/3' (50%), and 200°C/5, which showed germination rates that were signifi cantly lower (4.5%, P<0.05). Th e results indicated that S. nitens seeds were not stimulated or killed by high temperatures, except when an extreme temperature and time of exposure were combined (200°C/5'). When wet grasslands burn, where S. nitens grows, the fi re passes very quickly over the area and the temperature during the fi re may not exceed 150ºC. Under these conditions, our results suggest that S. nitens seeds can potentially survive most fi res. Th ese fi ndings are essential for making management recommendations for this species, which has high commercial value. IntroduçãoO fogo é um fator determinante para a persistência de diversas espécies no Cerrado brasileiro, sendo comumente utilizado como técnica de manejo em áreas naturais e de agricultura (Alho & Martins 1995). Além de comumente usado para o manejo da pecuária extensiva, o fogo, na região do Jalapão (Tocantins), é também um importante instrumento de manejo nos campos úmidos, onde ocorre o capim dourado (Syngonanthus nitens (Bong.) Ruhland, Eriocaulaceae). Esta espécie é utilizada na produção artesanal, representando importante fonte de renda. O artesanato é produzido com os escapos fl orais de S. nitens e extrativistas acreditam que a fl oração dessa espécie é maior um ano após a queima (Schmidt et al. 2007), fazendo com que o manejo tradicional de S.nitens pelas comunidades do Jalapão envolva queimadas regulares, com intervalo de 2 a 3 anos.Embora o conhecimento tradicional indique que o fogo estimule a fl oração de S. nitens, não há informações sobre os efeitos de altas temperaturas na sobrevivência e germinação de sementes dessa espécie. Estudos anteriores mostraram que, apesar da capacidade de reprodução clonal de S. nitens, a reprodução por sementes é importante para a dinâmica populacional dessa espécie, podendo ser responsável pelo recrutamento de cerca de 40% dos novos indivíduos (Schmidt et al. 2007). Experimentos que determinem efeitos de altas temperaturas na germinação e viabilidade de suas sementes podem, portanto, contribuir signifi cativamente para o manejo dessa espécie economicamente importante. A determinação dos efeitos das altas temperaturas e diferentes tempos de exposição sobre as sementes de S. nitens permitirá fornecer i...

Assessing the consequences of human exploitation at different intensities on ecosystem services is important in the Brazilian Araucaria Forest biome, because it has been drastically reduced, mainly due to the exploitation of Araucaria angustifolia (Bertol.) Kuntze for wood. The inclusion of A. angustifolia on the list of Brazilian endangered plant species places the harvesting of Araucaria nuts as the most important provisioning service in this type of ecosystem. The aim of this study was to determine the trade-offs related to provisioning, supporting and regulating ecosystem services in the Araucaria Forest at different intensities of nut harvesting, by addressing ecosystem attributes that assure forest sustainability. Six indicators of ecosystem services were evaluated in harvested and non-harvested areas in Brazilian Araucaria Forest fragments. Trade-offs were examined under five harvesting intensities. The supporting services were the most sensitive to the harvesting intensity. The results indicate that a harvesting threshold of between 60% and 85% of the nuts produced guarantees forest sustainability. In addition, areas under higher harvesting intensities provide more short-term benefit services at the local scale that can be included in the formal market.ARTICLE HISTORY