Litter decomposition rate of Tamaulipan thorn scrub and an introduced plant species

Abstract

Litter decomposition is a key process for nutrients cycling in the ecosystems. Knowledge of the decomposition rate of vegetation litter of an area can helps to a better understanding of soil fertility and to propose sound management practices that favor the availability of nutrients for plants. The objectives of this study were i) to evaluate initial decomposition rate of litter produced in a Tamaulipan thorn shrub area and in a eucalyptus plantation (Eucalyptus camaldulensis) which is an introduced species in the region, and ii) to estimate correlation values between degradation weight loss by the decomposition process and climatic factors (rainfall and temperature). Thirty-two litterbags (1 mm mesh eye) containing litter of shrub and eucalyptus were place on the field. Remaining mass evaluations were made monthly for 6 month, removing four bags each month. Decomposition rate was higher for the thorn shrub (35.11 %) than for the eucalyptus litter (24.91 %). The decomposition constant (k year^‒1), was higher for the Tamaulipan thorn shrub with k=0.934 than for eucalyptus (0.479). Decomposition litter mass remaining showed a negative correlation with temperature and evaporation, both for MET and eucalyptus, and only eucalyptus had a negative correlation to rainfall. The deposition of nutrients to the soil, as a result of litter decomposition would be slower in eucalyptus plantations than in MET areas, so the availability of nutrients may be limited at the time that rainfall pulses, which activate plants growth, occur and silvicultural practices must be established accordingly.