马尾松幼苗生长对钙浓度的响应

Responses of seedlings growth of Pinus massoniana to calcium concentration

研究不同钙浓度下马尾松幼苗的生长特性,为马尾松人工林选地和林地施肥管理提供理论依据。以1年生马尾松幼苗为研究对象,采用温室砂培法研究和比较不同钙浓度(0、0.4、1、2、3、4、10、20、40和100 mmol·L^(-1))下马尾松幼苗的生长情况。结果表明:马尾松幼苗生长势从强到弱的Ca^(2+)浓度顺序为2 mmol·L^(-1)>1 mmol·L^(-1)>3 mmol·L^(-1)>0.4 mmol·L^(-1)>0 mmol·L^(-1)>4 mmol·L^(-1)>10 mmol·L^(-1)>20 mmol·L^(-1)>40 mmol·L^(-1)>100 mmol·L^(-1)。供Ca^(2+)浓度低于2 mmol·L^(-1)时,马尾松总生物量、根体积、根尖数和根系活力等随供Ca^(2+)浓度增大而显著增加;供Ca^(2+)浓度高于2 mmol·L^(-1)时,茎生物量、总生物量、根尖数和根系活力等随供Ca^(2+)浓度增加而显著下降。不同Ca^(2+)浓度下,马尾松各项生长指标与植株生物量均呈显著正相关(p<0.01),与供钙浓度总体呈二次函数关系;马尾松幼苗的根生物量、成活率、总生物量、茎生物量和根尖数与供Ca^(2+)浓度间关系极其密切。本研究结果可直接用于马尾松林土壤施肥及其造林地选择,为马尾松人工林培育提供参考。

Growth characteristics of one-year-old Pinus massoniana seedlings under different calcium(Ca^(2+)) concentrations were studied in order to provide theoretical basis for choosing afforestation stand and fertilization managements of P. massoniana. A greenhouse sand culture experiment was carried out to investigate the growth difference of P. massoniana seedlings on various concentrations [0, 0.4, 1, 2, 3, 4, 10, 20, 40 and 100 mmol·L^(-1)] of Ca^(2+). The results showed that:the Ca^(2+) concentration order of P. massoniana seedling growth potential was 2 mmol·L^(-1) > 1 mmol·L^(-1) > 3 mmol·L^(-1) > 0.4 mmol·L^(-1) > 0 mmol·L^(-1) > 4 mmol·L^(-1)> 10 mmol·L^(-1) > 20 mmol·L^(-1) >40 mmol·L^(-1) > 100 mmol·L^(-1).When Ca^(2+) concentration was below 2 mmol·L^(-1), total biomass, root volume, tip number and root activity were increased significantly with the Ca^(2+) concentrationsincreased. Stem biomass, total biomass, tip number and root activity were decreased markedly when Ca^(2+) concentration was above 2 mmol·L^(-1). Growth indexes had a strong positive correlation with total biomass under different Ca^(2+) concentrations(p < 0.01) and were almost correlated with Ca^(2+) supply with a quadratic function. The root biomass, survival rate, total biomass, stem biomass andtip number of P. massoniana seedling were very closely associated with Ca^(2+) concentration. The results of this study could be used for afforestation stand choosing and fertilizer applying of P. massoniana, and it could provide a scientific basis for plantation cultivation of P. massoniana.