安塞人工沙棘林地上部生物量和净初级生产量

Biomass and net primary productivity of above-ground parts of artificial Hippophae rhamnoides L. stand in Ansai

采用收获法测定安塞沙棘人工林不同林龄林分的地上部生物量 ,分析沙棘人工林发育过程中地上部生物量和净初级生产量的变化趋势 ,建立沙棘单株地上部各器官分量的回归模型。结果表明 :沙棘人工林 4～ 5a即可郁闭 ,郁闭度为 0 .8～ 0 .9。 1～ 8龄内 ,地上部生物量随林龄增加而增加 ,8～ 11龄增加缓慢 ,11～ 13龄趋于稳定 ,13龄的沙棘人工林地上部生物量为 115 1g m2 ,地上部生物量的器官分配为 :主茎 410g m2 (占 35 .6 % ) ,枝 478g m2 (占41.5 % ) ,叶 2 15g m2 (占 18.8% ) ,果 2 0g m2 (占 0 .0 2 % ) ,枯枝 2 8g m2 (占 0 .0 2 % )。 8龄沙棘人工林的净初级生产量为 6 0 0g (m2 ·a) ,此林龄后需采取林中间种油松 (PinustabulaeformisCarr.)、杨树 (Populussp .)

The harvest method was used to study the biomass of above\|ground parts of artificial \%Hippophae rhamnoides \%L. stand of different ages. The dynamics on the biomass and net primary productivity of above\|ground parts in the course of development were analyzed in detail. The optimum regression models of biomass of different organs of above\|ground part of \%Hippophae rhamnoides \%L. were built. The results show that artificial \%Hippophae rhamnoides \%stand crowned closer after 4～5 years, crown density 0.8～0.9.Biomass of above\|ground parts in 1～8 year \|stand increased with age of stands, 8～11 year\|stand slowly increased, 11～13 year\|stand trended to stable. Biomass of above\|ground parts of 13 year\|stand was 1 151 g/m\+\{2\}, and its allocation was: main stem 410 g/m\+\{2\}(accounted for 35.6%), branch 478 g/m\+\{2\}(accounted for 41.5%), leaf material 215 g/m\+\{2\}(accounted for 18.8%),\ fruit 20 g/m\+\{2\}(accounted for 0.02%) and dry\|branch 28 g/m\+\{2\}(accounted for 0.02%). Net primary productivity of 8 year\|stand was 600 g/(m\+\{2\}·a), after this age of stands the measures of inter\|planting tree species, herb species or flat cutting may be used to reform the stand.