杉木观光木混交林细根灰分含量和热值动态

通过对杉木观光木混交林群落细根的灰分含量、热值及动态变化进行研究 ,结果表明 ,杉木活、死细根灰分含量动态变化呈单峰型 ,3月灰分含量最高 ;观光木的则呈双峰型 ,在 3月和9月出现峰值 ;林下植被细根灰分含量的变化亦呈单峰型 ,但较为平缓 ,最大值出现在 5月份 .杉木细根的干重热值变化呈“V”型 ,观光木的干重热值呈“W”型 ,而林下植被的干重热值则呈单峰型 ,最大值出现在 9月 .细根的灰分含量、干重热值均与细根径级成反比 ,但活细根的灰分含量明显低于相应径级的死细根 ,而活细根的干重热值则高于死细根 .观光木细根的灰分含量、去灰分热值比杉木的高 ,但其干重热值却低于杉木的 .林下植被层细根的灰分含量低于观光木的 ,但高于杉木的 ,而其干重热值和去灰分热值均低于后两者

Seasonal Dynamics of Ash Content and Caloric Value for Fine Roots of Mixed forest of Chinese fir and Tsoongiodendron odorum

Studies on ash content and caloric value for fine roots of mixed forest of Chinese fir (Cunninghamia lanceolata) and Tsoongiodendron odorum were carried out.The seasonal change of ash content for both living and dead fine roots showed a single apex line peaked in March for Chinese fir,a double apices one peaked both in March and September for Tsoongiodendron odorum,and a smoother single apex one peaked in May for undergrowth.Changes of gross caloric value for both living and dead fine roots showed a "V" line for Chinese fir and a "W" line for Tsoongiodendron odorum,and that for undergrowth exhibited a single apex onepeaked in September.Ash content and gross caloric value were negatively relat ed to diameter size of roots, and ash content was higher for dead root and gross caloric value higher for living roots.{Tsoon }giodendron odorum had a higher level of ash content and ash free caloric value,and lower gross caloric value than Chinese fir.Both of gross caloric value and ash free caloric value of fine rootsfor undergrowth were lower than that for Chinese fir and Tsoongiodendron odorum,but its ash content was higher than Chinese fir and lower than Tsoongiodendron odorum.