Research Information System
FRESENIUS ENVIRONMENTAL BULLETIN, vol.18, no.12, pp.2380-2387, 2009 (SCI-Expanded)
Soil enzyme activities are widely accepted as sensitive indicators of ecological disturbance. This study investigated the effects of forest wildfires on soil urease activity (involved in N cycle) and selected soil chemical properties (total Nitrogen, ammonium nitrogen, organic carbon, C: N ratio and cation exchange capacity) in four different fire-altered forest ecosystems in Canakkale, Turkey. The wildfires occurred 12, 8, 2 years and 2 weeks before soil sampling, (Cumali, CU; Gelibolu, GB; Kesan, KS; and Lapseki, LP; respectively). Except recently burned site (LP), other sites showed the similar trends for all measured soil properties. LP site differs from the others due to having different plant community. C: N ratios were higher in burned sites than unburned sites whereas CEC were lower in burned sites than unburned sites. Soil organic C, total N and NH4-N contents decreased in CU, GB and KS sites and increased in LP site. The t test (2 tailed) showed that burning significantly decreased soil organic C in GB and KS sites (P<0.05), total nitrogen content in GB site (P<0.01) and soil NH4-N content in KS site relative to unburned-burned soils. Soil urease enzyme activities were higher in unburned soils in GB, KS and LP sites; however, burning significantly (P<0.05) decreased soil urease activity in GB and KS sites. Also, CEC and soil urease activity was positively correlated (0.859, P<0.1) in burned soils. The results showed that soil urease enzyme activity showed a better explanation for discriminating fire effect.