The home-field advantage (HFA) hypothesis establishes that plant litter decomposes faster at ‘home’ sites than in ‘away’ sites due to more specialized decomposers acting at home sites. This hypothesis has predominantly been tested through ‘yes or no’ transplanting experiments, where the litter decomposition of a focal species is quantified near and away from their conspecifics. Herein, we evaluated the occurrence and magnitude of home-field effects on the leaf litter decomposition of Myrcia ramuliflora (O.Berg) N. Silveira (Myrtaceae) along a natural gradient of conspecific litterfall input and also if home-field effects are affected by litter and soil traits. Litter decomposition of M. ramuliflora was assessed through litterbags placed in 39 plots in a tropical heath vegetation over a period of 12 months. We also characterized abiotic factors, litter layer traits, and litter diversity. Our results indicated the occurrence of positive (i.e. Home-field advantage) and negative (i.e. Home-field disadvantage) effects in more than half of the plots. Positive and negative effects occurred in a similar frequency and magnitude. Among all predictors tested, only the community weighted mean C/N ratio of the litterfall input was associated with home-field effects. Our results reinforce the lack of generality for home-field effects found in the literature and thus challenge the understanding of litter-decomposer interaction in tropical ecosystems.

Cactaceae is one of the most threatened plant families, in part as a result of the illegal extraction of plants for ornamental use. However, reports of the seizure and reintroduction of cacti are scarce and do not include species of Melocactus, the genus of Cactaceae in Brazil that has the highest number of threatened species. The coroa-de-frade Melocactus violaceus is endemic to Brazil and categorized as Vulnerable on the IUCN Red List. We report the seizure of 37 individuals of coroa-de-frade extracted illegally from their natural habitat, the results of their reintroduction to Paulo César Vinha State Park, in Espírito Santo state, Brazil, and provide information for environmental monitoring agencies regarding how to proceed in seizure cases, with the goal of minimizing the impacts of this illegal practice on the species. After seizure, 25 individuals were cultivated in a greenhouse and 12 were reintroduced in restinga, the natural area of occurrence of the species. After 6 months, survival was 76% for those individuals cultivated in the greenhouse and 84% for those planted in restinga, showing that rapid reintroduction of species with ornamental appeal, preferentially in their natural habitat, can reduce the impacts of illegal extraction. This reintroduction protocol can be used by managers of conservation units, contributing to the maintenance of threatened cactus species in their natural habitat.

Four species of the genus Graphis Adans. are described as new to science, namely G. archeri, G. invisibilis, G. lueckingii and G. paranaensis. These new species were found growing in restinga forest in southern Brazil.

Competition and predation have often been referred to as key forces regulating community structure. However, in the last decade great attention has been paid to the structuring role of positive interactions between plants, which occur when the presence of one species enhances fitness, survival or growth of another (Bruno et al. 2003, Callaway et al. 2002). Positive and negative interactions are unlikely to occur separately in nature (Brooker & Callaghan 1998, Holmgren et al. 1997), and the overall importance of positive interactions on community structure tends to be higher in resource-poor environments (Callaway et al. 2002). Moreover, this balance can be subjected to spatial and temporal shifts (Callaway 1998, Morris & Wood 1989, Tielbörger & Kadmon 1997) linked with plant ontogenetic development and/or changes on resource availability (see Callaway & Walker 1997).