Unravelling ecosystem functions at the Amazonia-Cerrado transition: II. Carbon stocks and CO2 soil efflux in cerradao forest undergoing ecological succession

作者：Peixoto Karine S; Marimon Junior Ben Hur; Marimon Beatriz S^*; Elias Fernando; de Farias Josenilton; Freitag Renata; Mews Henrique A; das Neves Eder C; Prestes Nayane Cristina C S; Malhi Yadvinder

来源：Acta Oecologica, 2017, 82: 23-31.

DOI：10.1016/j.actao.2017.05.005

• Ecological tension zone
• Litter layer
• Secondary succession
• Soil respiration

The transition region between two major South American biomes, the Amazon forest and the Cerrado (Brazilian savanna), has been substantially converted into human-modified ecosystems. Nevertheless, the recovery dynamics of ecosystem functions in this important zone of (ecological) tension (ZOT) remain poorly understood. In this study, we compared two areas of cerractdo (a forest-woodland of the Brazilian savanna; Portuguese augmentative of cerrado), one in secondary succession (SC) and one adjacent and well preserved (PC), to test whether the ecosystem functions lost after conversion to pasture were restored after 22 years of regeneration. We tested the hypothesis that the increase in annual aboveground biomass in the SC would be greater than that in the PC because of anticipated successional gains. We also investigated soil CO2 efflux, litter layer content, and fine root biomass in both the SC and PC. In terms of biomass recovery our hypothesis was not supported: the biomass did not increase in the successional area over the study period, which suggested limited capacity for recovery in this key ecosystem compartment. By contrast, the structure and function of the litter layer and root mat were largely reconstituted in the secondary vegetation. Overall, we provide evidence that 22 years of secondary succession were not sufficient for these short and open forests (e.g., cerrado) in the ZOT to recover ecosystem functions to the levels observed in preserved vegetation of identical physiognomy.

• 出版日期2017-7