Soil biological properties in multistrata successional agroforestry systems and in natural regeneration

The diversity of cultivated plants in the agroforestry systems can create conditions to maintain the vital edaphic processes similar to natural regeneration areas. We studied agroforestry systems with five (AF5) and ten years (AF10) of age in comparison with natural regeneration areas for 10 years (NR) in the Atlantic Forest Biome in an area of environmental fragility. The microbial biomass carbon (MB-C), soil basal respiration (BResp), metabolic quotient (q-CO2) and microbial quotient (q-mic) were evaluated in the entire profile of a Typic Udorthents, obtaining stratified data in the 0–2.5; 2.5–5; 5–10; 10–15; 15–30; 30–45 and 45–60 cm layers. The NR area had the highest MB-C (866 mg C kg−1 soil) and BResp (5 mg C-CO2 kg−1 soil h−1) in the 0–2.5 cm layer in relation to the AF5 (686 mg C kg−1 soil; 4 mg C-CO2 kg−1 soil h−1) and AF10 (478 mg C kg−1 soil; 4 mg C-CO2 kg−1 soil h−1). However, the ratios did not differ among treatments, presenting average values in the profile of 7 mg C-CO2 g−1 MB-C h−1 for q-CO2 and 1.6 % for q-mic, demonstrating vital process similarity between systems. The phytosociological characteristics that interfere with the microbiological attributes were the plant species richness (0–2.5 cm) and plant diversity (2.5–5 cm). The epiedaphic fauna active in the litter was also assessed by pitfall traps and the average number of individuals per trap (238 for NR, 281 for AF5, 299 for AF10), the order richness (15 for NR; 14 for AF5, 13 for AF10) and relative frequencies did not differ among treatments, confirming that agroforests are in an ecosystem self-regulation condition function similar to natural regeneration, even with the removal of food products and income generation for the farmers.