不同年龄杉木林土壤氮矿化及其对施肥增温的响应

选择湖南省会同县3个不同年龄的杉木人工林,并以次生阔叶林为对照,采用实验室控制培养箱培养法.研究4个森林土壤氮矿化速率及其对施肥和温度升高的响应.结果表明:阔叶林土壤净矿化速率和净硝化速率最低,杉木林中21 a杉木林净矿化速率最高,13 a杉木林净矿化速率最低;净硝化速率随着杉木年龄的增长呈递增的趋势.施肥能促进土壤净矿化作用,林分年龄越大的杉木林土壤促进作用越大.升温则抑制杉木林土壤净矿化作用,但对阔叶林有促进作用;对净硝化速率产生的影响不显著.施肥增温处理的影响,介于施肥作用与增温作用之间,同施肥相比,抑制土壤净矿化作用,对21 a杉木林的抑制作用最大,对杉木林净硝化速率起促进作用.

Speed of Soil Nitrogen Mineralization and Effect of Fertilizer Combined with Warming on It in Different Ages Chinese Fir Plantation

Three different ages Chinese fir plantation in Huitong were chosen as experimental objects and secondary broad-leaved forest was chosen as control,using laboratory control incubator culture method to study the speed of soil nitrogen mineralization and effect of it on fertilizer warming in four plantations.The results revealed that the speeds of net mineralization and net nitrification in broad-leaved forestry were the lowest;among Chinese fir plantation,the speed of net mineralization in 21-year-old Chinese fir plantation wag the highest,and the speed of net mineralization in 13-year-old Chinese fir plantation was the lowest;the speed of net nitrification showed a increasing tendency with increasing age of Chinese fir plantation.Fertilizer application could promote the soil net mineralization,and the promoting effect was more significant in older Chinese fir plantation.Warming will inhibit soil net mineralization in Chinese fir plantation,but promote soil net mineralization in broad-leaved forestry;warming has no significant effect on speed of net nitrification in Chinese fir plantation and broad-leaved forestnr.The effect of fertilizer combined with warming treatment was between the effect of fertilizer application and the effect of warming treatment;compared with the effect of fertilizer application,the treatment of fertilizer combined with warming will inhibit soil net mineralization.which has the most inhibiting effect for 21-year-old Chinese fir plantation,and promote the speed of net nitrification in Chinese fir plantation.