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Rupestrian landscapes are characterized by vegetation mosaics comprised of different plant communities and strongly linked to environmental filters. These environments are nutrient-impoverished, and possess water retention deficits and high solar exposure. This study aimed to determine whether chemical properties of the soil shape the arboreal-shrub vegetation structure in two neighboring habitats; a rupestrian cerrado and a rupestrian grassland. We hypothesized that the habitat with higher soil chemical properties would have higher parameters for vegetation structure, and different species composition. We expected higher chemical properties of the soil to favor a greater variety of plant life-forms. A total of 1349 individuals of 85 species belonging to 24 families were recorded; 1141 individuals (65 species) in the rupestrian cerrado, and 208 individuals (20 species) in the rupestrian grassland. Overall, Asteraceae, Fabaceae and Melastomataceae had greater species richness in both areas. Both habitats floristic composition was strongly influenced by differences in soil chemistry. In the cerrado, species richness, composition, soil nutrient availability and acidity were greater than in the grassland. We demonstrated that variation in soil chemistry influences plant species richness and composition, and structural complexity of vegetation, in both contiguous rupestrian environments, and that soil chemistry heterogeneity yields different plant life-form strategies.

Mistletoes obtain nutrients and water from their hosts, with varying effects among those hosts. We assessed the factors that influence the colonization of the mistletoe Struthanthus flexicaulis on Baccharis dracunculifolia and the subsequent effects on host performance. We evaluated the incidence of S. flexicaulis according to size (height classes) and architecture of the host as well as its effects on various physiological parameters of the host. Furthermore, we assessed the occurrence of insect galls induced by Baccharopelma dracunculifoliae (Psyllidae), including the number of leaves infected, and the mortality of infected and non-infected branches. Taller hosts had a higher abundance of mistletoes (60%, p> 0.05). Physiological parameters of hosts were not affected by parasitism, although galling occurred more often (p <0.05) and leaf loss increased (p>0.05) on infected branches. Taller individuals are more colonized by mistletoes and more architecturally complex hosts support a greater number of mistletoes. Mistletoe causes a top-down effect on host-associated organisms on parasitized branches. Mistletoes had a strong top-down effect on B. dracunculifolia due to a reduction in the number of leaves on parasitized branches and the replacement of the bush crown, as well as an increased incidence of insect galls. Furthermore, the occurrence of a heavy parasite load increased the mortality rate of the host branches.

The Cerrado (Brazilian Savanna) biome suffers intense degradation due to several anthropic activities and its recovery is extremely important for the restoration of environmental quality. Therefore, the present study tested the survival and growth of seedlings of the grass Schizachyrium tenerum produced by the division of clumps. The experiment was carried out in a greenhouse using Reddish Oxisol, dystrophic of "cerrado sensu stricto" and Litholic Neosol dystrophic of quartzitic rupestrian grassland with and without the addition of limestone and NPK. Survival of S. tenerum was also compared between being grown in a greenhouse and directly in the field in full sun. Seedlings of S. tenerum had greater survival, total growth, number of tillers and accumulation of biomass when cultivated in Reddish Oxisol and Reddish Oxisol with limestone added than in the other treatments. Seedling survival was three times greater when grown in a greenhouse than in full sun.