鼎湖山自然保护区不同演替阶段森林土壤中有效微量元素状况研究

Study on availability of micronutrients in soils under three different forests of Dinghushan Nuture Reserve

三种森林表层土壤中有效微量元素的平均含量顺序为 :Fe >Zn>Mn>B >Cu >Mo,马尾松林的含量顺序为 :Fe>Zn>Cu >B >Mn >Mo,混交林和阔叶林与平均含量一致。三种森林有效Fe的含量均极高 ,表现出富铁状况 ,而有效Mn含量甚微 ,表明该区森林均严重缺Mn,有效Cu和Zn的含量处于中等水平 ,均高于其临界值。但处于演替初期阶段的马尾松林还缺B和Mo,混交林也略缺Mo。相关分析结果表明 ,土壤pH值与所考察的所有微量元素有效量之间均呈负相关 ,且与有效B、Cu和Fe相关极显著 (P <0 .0 1 ) ,与有效Mo相关显著 (P <0 .0 5 ) ;有机质与所考察的所有微量元素有效量之间均呈正相关 ,且与有效B和Fe相关极显著 。

The order of average content of available micronutrients in upper soils in the three forests was Fe>Zn>Mn>B>Cu>Mo,and that of Pinus massoniana forest was Fe>Zn>Cu>B>Mn>Mo,but that of pine-broadleaf mixed forest and monsoon evergreen broadleaf forest was consistent with that of the average. Among all the available micronutrients,Fe was the most abundant,and Mn the most insufficient,indicating that the forests of Dinghushan were rich in Fe and short of Mn. The contents of available Cu and Zn were at a middle level,and were higher than their critical values respectively. Moreover,the soil of Pinus massoniana forest was destitute of available B and Mo,and that of pine-broadleaf mixed forest was somewhat insufficient of available Mo.We found that soil pH was negatively correlated with the availability of all the micronutrients discussed here,and was significantly correlated with available B,Cu and Fe at P=0.01 level,with Mo at P=0.05 level. Soil organic matter was positively correlated with the availability of all the micronutrients,and was significantly correlated with B and Fe at P=0.01 level and with Mn at P=0.05 level.