Biogeochemical and stable isotope dataset for evaluating prescribed fire impacts on litter and soil

Prescribed fire is used to reduce fuel loads in forestry, but its impact
on litter and soil properties requires further understanding. We measured
pH, carbon and nitrogen concentrations, C:N ratio, and stable isotope
composition (δ¹³C, δ¹⁵N) in litter and surface soil before, one day after,
and one year after a low-severity prescribed burn in a Mexican montane
forest. Because prescribed burns primarily combust surface litter while
limiting soil heating, we expected rapid litter responses and delayed soil
responses. One day after the burn, litter pH increased from 4.9 to 8.4,
δ¹⁵N increased from -3.7‰ to -0.3‰, and the C:N ratio decreased from 44 to
21. One year after the burn, litter δ¹⁵N decreased toward pre-burn values
(-1.5‰), while the C:N ratio increased to 84, nearly double the initial
value. In soil, pH did not differ significantly one day after the burn
(5.1 to 5.2). Soil δ¹⁵N increased from -0.2‰ to 1.6‰ one day after the
burn and remained enriched one year after (2.0‰). Litter and soil δ¹³C
showed no significant changes across the burn chronology.δ¹⁵N and C:N
revealed decoupled trajectories of litter and soil and can be used as
sensitive indicators of fire effects in managed forests.