| 【Objective】The changes of soil chemical properties of pure eucalyptus forest and mixed forest
(eucalyptus + Castanopsis hystrix) under different simulated acid rains were studied. 【Method】 The pH of the acid
rain was simulated to be 3.0, 4.0, 5.6 and 6.0 by a strict soil column leaching test.【Result】 The pH values of soil
and soil leaching solution decreased with the decrease of acid rain pH under acid rain treatment. The average pH of
pure eucalyptus forest soil decreased by 1.41, and that of mixed forest (eucalyptus + C. hystrix) decreased by 1.66.
The nutrient contents of the leaching solution increased with the decrease of acid rain pH; the contents of soil total N,
ammonium N and nitrate N in the two forests increased first and then decreased with the decrease of acid rain pH, and
soil P and available P in the pure eucalyptus forest decreased significantly with the decrease of acid rain pH while there
was no significant change in soil P and available P in the mixed forest (eucalyptus + C. hystrix). Under same pH (pH=3.0),
compared with CK, the decline rates of total N, nitrate N and ammonium N in the pure eucalyptus forest soil were 28.7%,
46.6% and 12.4%, respectively, and those of the mixed forest(eucalyptus + Castanopsis hystrix) were 18.9%, 23.5% and 11.3%, respectively. 【Conclusion】 The comparison of the two forest stands shows that the buffering capacity of mixed forest
of eucalyptus and C. hystrix to acid rain is stronger than that of pure eucalyptus forest |
