Shade alters savanna grass layer structure and function along a gradient of canopy cover

This is the author accepted manuscript. The final version is available from Wiley via the DOI in this recordData availability statement: Data used for this study are available as supporting information.Aim: In savannas, a grass-dominated ground layer is key to ecosystem function via grass–fire feedbacks that maintain open ecosystems. With woody encroachment, tree density increases, thereby decreasing light in the ground layer and potentially altering ecosystem function. We investigated how light availability can filter individual grass species distributions and whether different functional traits are associated with response to a shade gradient in a landscape experiencing woody encroachment. Location: Savanna–forest mosaic in the Cerrado domain, southeastern Brazil. Methods: Along an encroachment gradient of increasing tree leaf area index (LAI) and shade, we determined how changing light availability alters grass diversity and ground layer structure relative to grass cover and grass functional traits (photosynthetic pathway, underground storage organs, bud protection and traits related to grass shape, size and leaf dimensions). Results: Increasing shade led to a decrease in grass cover and grass species richness, and also compositional and functional changes. We found that where tree LAI reached 1, grass cover was reduced by 50% and species richness by 30%. While C4 grass species abundances decreased with increasing shade, the opposite pattern was true for C3 grasses. There were only small differences in light preferences among C4 subtypes, with phosphoenolpyruvate carboxykinase (PCK) species tolerating slightly more shaded conditions. Persistence of some C4 species under more shaded conditions was possible, likely due to an ability to store starch reserves via underground storage organs. Conclusions: Woody encroachment changes diversity and structure of the grassy layer that is critical to the functioning of savanna ecosystems, highlighting the dependence of the diverse grass layer on open and sunny conditions. Our results suggest a threshold of tree cover close to LAI ≈ 1 as being critical to cerrado grassy layer conservation.National Science Foundation (NSF)São Paulo Research Foundation (FAPESP)National Council for Scientific and Technological DevelopmentCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Flora and Structure of Mata Santa Elisa: an Environmental Patrimony in Campinas, SP

Tropical forests include remnants that should be characterized and monitored for long-term conservation. With this in mind, we performed a survey of the floristic composition and structure of the Mata Santa Elisa (Campinas, SP), and compared it to other fragments of semi-deciduous seasonal forest in the municipality. In Mata Santa Elisa, 506 living arboreal specimens were found, belonging to 100 species, 75 genera and 32 families. At the time of this work, the fragment was well-preserved and contained exclusive species and those of economic interest or potential, highlighting its importance in the region.Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP)Instituto Agronômico de Campinas (IAC)Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP