Linking species and ecosystems often relies on approaches that consider how the traits exhibited by species affect ecosystem processes. One method is to estimate functional diversity (FD) based on the dispersion of species in functional trait space. Individuals within a species also differ, however, and an unresolved challenge is how to include such intraspecific variability in a measure of functional diversity. Our solution is to extend an existing measure to variation among individuals within species. Here, simulations demonstrate how the new measure behaves relative to one that does not include individual variation. Individual-level FD was less well associated with species richness than species-level FD in a single trait dimension, because species differed in their intraspecific variation. However, in multiple trait dimensions, there was a strong association between individual- and species-level FD and richness, because many traits result in a tight relationship between functional diversity and species richness. The correlation between the two FD measures weakened as the amount of intraspecific variability increased. Analyzing natural plant communities we found no relationship between species richness and functional diversity. In these analyses, we did not have to specify the source of intraspecific variation. In fact, the variation was only among individuals. The measure can, however, include differences in the amount of intraspecific variation at different sites, as we demonstrate. Including intraspecific variation should allow a more complete understanding of the processes that link individuals and ecosystems and provide better predictions about the consequences of extinctions for ecosystem processes.

The cerrado, a savanna-like formation, is the second-most widespread vegetation type in Brazil. Its core region occupies the Brazilian Central Plateau, with a seasonal climate, including wet summer and dry winter. We studied the reproductive phenological patterns of the cerrado plant community in Emas National Park (central Brazil). Monthly field trips revealed 601 species, classified, according to their dispersal syndromes, into anemo-, auto-, or zoochorous species, when they were dispersed by wind, explosion or gravity, or animals, respectively. We analysed the flowering and fruiting patterns of the community in relation to dispersal syndromes, comparing the herbaceous and the woody components. The herbaceous component was characterised by a majority of autochorous species, and the woody component, by a majority of zoochorous species. There was a striking seasonality in the community-wide pattern of flowering and fruiting, although this was different between the herbaceous and the woody components. Woody species flowered mainly during late dry and early wet seasons, whereas herbaceous species flowered especially during late wet season. In the dry season, when their diaspores can be dispersed more efficiently, the proportions of anemo- and autochorous fruiting species were higher. During the rainy season, when their fruits can be kept attractive for longer time, the number of fruiting zoochorous species reached its peak.

No abstract

Summary Colour signals are the main floral trait for plant–pollinator communication. Owing to visual specificities, flower visitors exert different selective pressures on flower colour signals of plant communities. Although they evolved to attract pollinators, matching their visual sensitivity and colour preferences, floral signals may also evolve to avoid less efficient pollinators and antagonistic flower visitors. We evaluated evidence for the bee avoidance hypothesis in a Neotropical community pollinated mainly by bees and hummingbirds, the campo rupestre. We analysed flower reflectance spectra, compared colour variables of bee‐pollinated flowers (bee‐flowers; 244 species) and hummingbird‐pollinated flowers (hummingbird‐flowers; 39 species), and looked for evidence of bee sensorial exclusion in hummingbird‐flowers. Flowers were equally contrasting for hummingbirds. Hummingbird‐flowers were less conspicuous to bees, reflecting mainly long wavelengths and avoiding red‐blind visitors. Bee‐flowers reflected more short wavelengths, were more conspicuous to bees (higher contrasts and spectral purity) than hummingbird‐flowers and displayed floral guides more frequently, favouring flower attractiveness, discrimination and handling by bees. Along with no phylogenetic signal, the differences in colour signal strategies between bee‐ and hummingbird‐flowers are the first evidence of the bee avoidance hypothesis at a community level and reinforce the role of pollinators as a selective pressure driving flower colour diversity.

RESUMO -(Variações fenológicas das espécies do cerrado em Emas -Pirassununga, SP). Foi estudada a flora vascular de uma área de cerrado, situada no distrito de Emas, município de Pirassununga, Estado de São Paulo (aproximadamente, 22°02'S e 47°30'W). Entre abril de 1994 e abril de 1995, realizou-se um levantamento florístico, em que foram amostradas 358 espécies. A partir dos dados deste levantamento, estudaram-se as variações fenológicas das espécies, procurando analisá-las como estratégias adaptativas. Os componentes herbáceo-subarbustivo e arbustivoarbóreo comportaram-se de maneira distinta. As espécies arbustivo-arbóreas floresceram principalmente no início da estação chuvosa, enquanto que as herbáceo-subarbustivas produziram flores, de modo geral, apenas no final da estação úmida, após período de acúmulo de carboidratos. As espécies do componente herbáceo-subarbustivo tiveram pico de frutificação no final da estação chuvosa, qualquer que fosse a síndrome de dispersão de seus diásporos. Já as espécies do componente arbustivo-arbóreo apresentaram comportamentos distintos, conforme a síndrome de dispersão. As espécies zoocóricas frutificaram ao longo de toda estação úmida, enquanto que as anemocóricas e autocóricas produziram frutos. principalmente no início da estação seca.Palavras-chave: cerrado, savana, Emas, fenologia ABSTRACT -(Phenological variations ofthe cerrado species in Emas -Pirassununga, SP). The vascular flora of the cerrado in Emas district, Pirassununga municipality, São Paulo State (approximately 22°02' S and 47°30'W) was studied. Between April1994 and April 1995 a floristic survey was carried out, when 358 species, representing 227 genera and 78 families, were found. During this survey, the phenologycal variations were observed and analysed as adaptive strategies. The woody and herbaceous components had distinct behaviours. The woody species flowered mainly at the beginning ofthe rainy season, while the herbaceous ones produced flowers generally at the end of that season, after a period of carbohydrate accumulation. The herbaceous species 1 Bolsa de Iniciação Científica, FAPESP, processo nO 94/0904-4

ABSTRACT

Acta bot. bras. 15(3): 289-304. 2001 289 RESUMO -(Composição florística do cerrado na Reserva Pé-de-Gigante (Santa Rita do Passa Quatro, SP)). Estudamos uma área de 1225 ha, composta principalmente por cerrado, situada em Santa Rita do Passa Quatro, estado de São Paulo (21°36-38'S, 47°36-39'W). Em três fisionomias de cerrado (campo cerrado, cerrado sensu stricto e cerradão), coletamos, durante 18 meses, em excursões mensais, espécimes em fase fértil e os identificamos em nível específico. Encontramos 360 espécies, pertencentes a 236 gêneros e 69 famílias. As famílias mais ricas foram: Fabaceae, Asteraceae, Poaceae e Rubiaceae. As fisionomias savânicas foram mais ricas do que a florestal. A razão entre espécies arbustivo-arbóreas e herbáceo-subarbustivas foi de aproximadamente 2:1. Analisamos a flora como um todo e seus componentes herbáceo-subarbustivo e arbustivo-arbóreo separadamente, comparando-os com outras áreas disjuntas de cerrado. Dessa comparação, obtivemos valores de similaridade (índice de Sørensen) de 0,47 a 0,81, que mostraram que a diversidade 3 foi maior no componente herbáceo-subarbustivo do que no componente arbustivo-arbóreo.Palavras-chave -cerrado, savana, fisionomia, florística.ABSTRACT -(Floristic composition of the cerrado in the Pé-de-Gigante Reserve (Santa Rita do Passa Quatro, southeastern Brazil)). We studied a 1225 ha area, composed mainly of cerrado, in Santa Rita do Passa Quatro, São Paulo State, southeastern Brazil (21°36-38'S, 47°36-39'W). In three cerrado physiognomies (campo cerrado -a wooded savanna, cerrado sensu stricto -a woodland, and cerradão -a tall woodland), we collected all vascular plants in reproductive stage, and identified them to species level. We found 360 species, representing 236 genera and 69 families. The richest families were: Asteraceae, Fabaceae, Poaceae, and Rubiaceae. The savanna physiognomies were richer than the forest one. The ratio between herbaceous and woody species was approximately 2:1. We analysed the whole flora and its two components separately, woody and herbaceous, comparing them with other disjunct cerrado areas. We obtained similarity values (Sørensen index) from 0.47 to 0.81, which showed that the 3 diversity of the cerrado was higher in the herbaceous component than in the woody one.

Fire is an important ecological factor that structures savannas, such as the cerrado, by selecting plant species and altering soil nutrient content. In Emas National Park, central Brazil, we compared soils under three different fire regimes and their relationship to the cerrado species they support. We collected 25 soil and vegetation samples at each site. We found differences in soil characteristics (p<0.05), with fertility and fire frequency positively related: in the annually burned site we found higher values of organic matter, nitrogen, and clay, whereas in the protected site we detected lower values of pH and higher values of aluminum. We also observed differences in plant community structure, with distinct floristic compositions in each site. Floristic composition was more related to sand proportion (intra-set correlation=0.834). Different fire frequencies increase environmental heterogeneity and beta diversity in the Brazilian cerrado.