A 55-year-old natural experiment gives evidence of the effects of changes in fire frequency on ecosystem properties in a seasonal Subtropical Dry forest

KOWALJOW, E.; MORALES, M.S.; WHITWORTH-HULSE, J.I.; ZEBALLOS, S.R.; GIORGIS, M.A.; RODRÍGUEZ CATÓN, M.; GURVICH, D.E.

LAND DEGRADATION & DEVELOPMENT

JOHN WILEY & SONS LTD

Año: 2018

1085-3278

Fire frequency has been highlighted as an important component of fire effects on ecosystems;nevertheless, there is scarce information about how fire modulates changesin ecosystem properties, particularly for subtropical dry forests. A long‐term naturalexperiment and a multiscale approach were used to analyze changes in ecosystemproperties in a subtropical dry forest subjected to contrasting fire regimes. Measurementswere taken in two adjacent sites that had contrasting fire regimes (low/highfire frequency), and vegetation and soil analyses were combined with dendrochronologicalmethods. Ten plots (20 × 20 m) were established in each site and soil (depth,chemical, and biological properties), and vegetation (species composition and growthof the dominant tree, Lithraea molleoides) variables were measured. Fire scars inL. molleoides were useful in determining fire history. Shrubs and grasses were moreabundant in the high fire frequency site, with a high cover of the exotic grass Melinisrepens, whereas trees and vines were more abundant in the low fire frequency site.Soil of the high fire frequency site tended to have lower C and nutrient content aswell a significant lower depth than those of the low fire frequency site. Growth ofL. molleoides individuals was lower in the high fire frequency site. Our results suggestthat the long‐term effects of high fire frequency probably increase both soil loss andfire frequency in the future due to changes in plant composition, indicating that frequentburning is not a sustainable management option for this seasonal subtropicaldry forest.