Abstract
Frost effects on savanna plant communities have been considered as analogous to those from fire, both changing community structure and filtering species composition. However, while frost impacts have been well-studied for the woody component of savannas, it is still poorly explored for the ground-layer community. Here, we investigated effects of frost in the Cerrado along a gradient of tree cover, focusing on ground-layer plant species, near the southern limit of the Cerrado in Brazil. We aimed to elucidate if the pattern already described for the tree layer also extends to the ground layer in terms of mimicking the effects of fire on vegetation structure and composition. We assessed how damage severity differs across species and across the tree-cover gradient, and we examined the recovery process after frost in terms of richness and community structure along the canopy cover gradient. Frost caused immediate and widespread dieback of the perennial ground-layer, with greatest impact on community structure where tree cover was lowest. However, frost did not reduce the number of species, indicating community resilience to this natural disturbance. Although frost mimicked the effects of fire in some ways, in other ways it differed substantially from fire. Unlike fire, frost increases litter cover and decreases the proportion of bare soil, likely hindering crucial processes for recovery of plant populations, such as seed dispersal, seed germination and plant resprouting. This finding calls attention to the risk of misguided conclusions when the ground layer is neglected in ecological studies of tropical savannas and grasslands.
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Data availability
The data sets used during the current study are partially presented as the supporting information and additional data are also available from the corresponding author upon reasonable request.
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Acknowledgements
We thank Instituto Florestal do Estado de São Paulo for the permission to develop this scientific research (SMA#26108-008.476/2014). This study was supported by U.S. National Science Foundation—NSF (DEB1354943), grant conceded to WAH. NALP was funded by São Paulo Research Foundation-FAPESP (grants #2016/17888-2, and #2017/20897-6). DRR was funded by National Council for Scientific and Technological Development-CNPq (grant #302897/2018-6). GD was funded by National Council for Scientific and Technological Development-CNPq (grant #309709/2020-2). This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil (CAPES)—Finance Code 001.
Funding
This study was supported by U.S. National Science Foundation-NSF (DEB1354943), grant conceded to WAH. NALP was funded by São Paulo Research Foundation-FAPESP (grants #2016/17888-2, and #2017/20897-6).
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NALP and GD conceived the research; GD, NALP and WAH designed methodology. NALP, GD, MGBC, RCRA and WAH performed experiments and data collection. NALP analyzed the data and wrote the manuscript with contributions of all the other authors.
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Communicated by Brian J. Wilsey.
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Pilon, N.A.L., Cava, M.G.B., Hoffmann, W.A. et al. Effects and response of the Cerrado ground-layer to frost along the canopy cover gradient. Oecologia 200, 199–207 (2022). https://doi.org/10.1007/s00442-022-05259-9
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DOI: https://doi.org/10.1007/s00442-022-05259-9