Avaliação de serviços ecossistêmicos em sistemas agroflorestais biodiversos e interações com a diversidade vegetal

Abstract

The time window for limiting global warming to 2°C is running out. There is alreadyaconsensus that agroforestry systems (SAF) are viable alternatives for climate mitigation, asthey produce a range of ecosystem services (SE). Quantifying these services canhelpdecision-making in management and the formulation of public policies to encouragelarge-scale employment of the SAF. This study evaluated the regulation and support servicesinthree biodiverse AFSs, a native forest fragment (MN), and a conventional plantation(PC)asreferences. From field collections, litter carbon stocks and soil organic carbon (COS) wereestimated up to one meter deep, soil microbiology was evaluated as a quality indicator andanallometric model was proposed for non-destructive estimates of microbial biomass (C-BMS)through geoprocessing using the normalized difference vegetation index (NDVI). SAF3produced an average annual stock of 5.21 tC/ha in the litter, 1.4 tC/ha more thanMN. InSAF2, the soil cover with remnants of urban pruning and biochar (pyrolysedvegetableorganic matter), contributed to the stock of 479.44 tC/ha in the soil with thehighestconcentration between 0 and 15 cm in depth. SAF1 (p=0.03) and SAF2 (p=0.04) differedstatistically from MN with higher COS values at depths of 50-100cm. SAF3(p=0.5809)was the one with the closest C-BMS values to those of MN, suggesting that theuseofthe herbaceous layer between the rows of trees has ensured the contribution of qualityorganicmatter to the soil. With Pearson's correlation coefficient of 0.44 between NDVI andC-BMS,the allometric model (C-BMS = -180 + 640*NDVI) for prediction of C-BMShadadjustedR2=0.18. This study reveals that biodiverse SAFs can produce regulatory and support SEsaswell as natural ecosystems. The results can support decision-making in choosingthetypeofmanagement in SAF and the formulation of public policies to accelerate the agroecologicaltransition process.