Evaluating belowground bud banks of native species from Cerrado: Structural, chemical, and ecological approaches

Abstract

Resprouting from belowground buds enables plants to survive after aboveground biomass loss in the Brazilian Cerrado. Although resprouting is a common functional strategy in disturbance-prone ecosystems, we poorly understand the anatomy of belowground bud-bearing organs. Here, we aimed to describe traits related to the resprouting ability of four native Cerrado species from an area under regeneration after the removal of a slash-pine plantation (Pinus elliottii), by analyzing their belowground bud-bank, the structural features of their belowground bud-bearing organs, and their storage compounds. We evaluated the belowground bud bank size of all species, conducted anatomical analyses to describe their belowground bud-bearing organs, identified the chemical compounds stored. The belowground bud bank size varied according to the number of belowground bases of aerial stems and branches emitted by the belowground bud-bearing organs. Anemopaegma arvense, Peltaea polymorpha, and Psidium laruotteanum presented xylopodia. The xylopodium of A. arvense had plagiotropic roots with adventitious buds. Moreover, A. arvense and Peritassa campestris presented cambial variants in their belowground organs (phloem wedges and successive cambia, respectively). Starch, phenolic compounds, and carotenoids were the main storage and protective compounds, occurring in the periderm, vascular rays, and parenchyma pith cells. Our findings suggest that the analyzed species were able to resprout after pine removal due to the maintenance of a belowground bud bank protected and resourced by belowground bud-bearing organs. Gaining such insight on belowground bud banks is essential in the understanding of the resprouting ability after natural and/or human-induced disturbances.