Journal of species lists and distribution Chec List 487 L ISTS OF S PECIES Check List 9(3): 487–503, 2013 © 2013 Check List and Authors ISSN 1809-127X (available at www.checklist.org.br) In South America, the largest savanna region is located in Brazil, and is called Cerrado, and as in other savannas, the fire regime is an important factor in the evolution of the landscape and, consequently, of the vegetation (Gottsberger and Silberbauer-Gottsberger 2006a). In savannic physiognomies the presence of trees is greater in areas protected from fire, especially in dry-shrub savannas, where protection allows the regeneration of the woody component (Moreira 2000). In general, the absence of fire benefits the woody component and increases the structural complexity of vegetation, while the passage of fire benefits the non-woody component and increases the presence of herbs and subshrubs in the landscape (Mistry 1998). In the Cerrado, most of the ongoing studies on dynamics have focused only on the tree layer (Libano and Felfili 2006; Aquino et al. 2007; Roitman et al. 2008, Carvalho and Felfili 2011). Studies that directly focus on understanding the temporal dynamics of the herbaceous and shrub layer over the years are still scarce, especially with regard to the grassland physiognomies of the biome (Eugênio et al. 2011). The Cerrado phytogeographical domain has a very heterogeneous physiognomy, that ranges from open grasslands to dense forests, but which has as the most common formation the savannic physiognomy, known as cerrado sensu stricto (Oliveira-Filho and Ratter 2002; Ab’Sáber 2003; Ribeiro and Walter 2008). The grassland formations include wet grassland (campo limpo), dry- shrub grassland (campo sujo) and “campo rupestre” (rupiculous field grassland) (Ribeiro and Walter 2008), and until 2007 these occupied 7% of the entire Cerrado. In the Federal District alone, they covered a total of 6,164 ha (Sano et al. 2007). The dry-shrub grassland (Campo sujo) is one of the Introduction The dynamic process in a community is characterized by patterns, mechanisms and, in many systems, successive disturbances are important sources of changes in the landscape (Glenn-Lewin and van der Maarel 1992). The progression of changes in the composition and structure of a community over time, due to disturbances in the environment, is conceptualized as a succession process or directional change (Buchanan 1982). Studies of temporal dynamics for grassland sites report that the suppression of disturbances such as fire plays a crucial role in the floristic and structural changes of these communities (San José and Fariñas 1991; Moreira 2000; Behling et al. 2007; Kahmen and Poschlod 2008; Ravi and D’Odorico 2009). Changes over time are related to differences in species abundance and composition, differences in the spectrum of life forms and functional characteristics. The suppression of fire in savannas intervenes in natural ecological processes, and in more open areas like grasslands, a gradual increase in the density of woody and fire-sensitive species can be seen (San José and Fariñas 1983; 1991; Silva et al. 2001; Durigan and Ratter 2006; Gardner 2006; Pinheiro and Durigan 2009). Savannas are considered dynamic ecotones, distributed between grassland formations and more densely vegetated areas (Coutinho 1978, Roitman et al. 2008). In these landscapes grasses and trees coexist, influenced by interactions with the climate, soil and disturbances such as fire, and fluctuations in any of these factors may result in an increase in certain life forms (Roitman et al. 2008). The intensification or suppression of disturbances modifies the composition of species in an area. The landscape is altered by the exclusion of sensitive species in the first case, and by the exclusion of resistant species in the second (Libano and Felfili 2006). Abstract: Studies of temporal dynamics for grassland sites report that fire suppression plays a crucial role in floristic changes. The objective of this study was to verify whether after seven years without fire, communities showed variations in terms of composition, life forms, pollination and dispersal syndromes. The first survey (T0) was conducted from September 1999 to October 2000, while the second (T1) took place from August 2006 to August 2007. The floristic results in T1 were compared with the survey in T0 through the Sorensen similarity index and Chi-square tests. Over time, there were differences in the composition, life forms and pollination and dispersion syndromes. The evidence of changes suggests that the frequency of the fire regime can be considered the main agent for change in the flora of these communities. 1 Universidade de Brasília, Instituto de Biologia, Departamento de Botânica. Campus Darcy Ribeiro, Instituto de Ciências Biológicas, bloco D, 1° piso. CEP 70910-900. Asa Norte, Brasília, DF, Brazil. 2 Universidade Católica de Brasília, Curso de Biologia, Laboratório de Botânica. Campus I - QS 07 Lote 01 EPCT, Águas Claras. CEP 71966-700 – Taguatinga, DF, Brazil. 3 Universidade de Brasília, Departamento de Engenharia Florestal. Campus Darcy Ribeiro, Brasília, DF, Brazil. In memoriam * Corresponding author. E-mail: aryanne_amaral@yahoo.com.br Aryanne Gonçalves Amaral 1* , Cássia Beatriz R. Munhoz 1 , Chesterton Ulysses Orlando Eugênio 1,2 and Jeanine Maria Felfili 3 Vascular flora in dry-shrub and wet grassland Cerrado seven years after a fire, Federal District, Brazil