论文部分内容阅读
养分再吸收作为植物保存养分的重要机制之一,在凋落物分解和养分循环中起着重要作用。为明确辽东山区主要树种养分再吸收状况,选择4种次生林树种:蒙古栎(Quercus mongolica)、色木槭(Acer mono)、胡桃楸(Juglans mandshurica)、花曲柳(Fraxinus rhynchophylla)和人工林落叶松(Larix spp.)为对象,测定了各树种叶片凋落前(成熟叶)后(凋落叶)全氮(N)、全磷(P)、全钾(K)浓度,并分析了养分再吸收特征。结果表明:所测树种凋落叶N、P、K浓度均显著低于成熟叶(落叶松K不显著);胡桃楸N再吸收率与蒙古栎、色木槭、花曲柳差异显著,花曲柳与蒙古栎、色木槭P再吸收率差异显著,色木槭K再吸收率与蒙古栎、胡桃楸、花曲柳差异显著(P<0.05);总体上,落叶松N、P、K再吸收率低于次生林树种,尤其是P再吸收率显著低于花曲柳、K再吸收率显著低于胡桃楸和花曲柳(P<0.05)。上述结果表明,落叶松通过降低养分再吸收率,提高凋落物养分输入量,对土壤养分有效性做出正反馈。
Nutrient re-absorption as one of the important mechanisms of plant nutrient conservation plays an important role in litter decomposition and nutrient cycling. In order to clarify the nutrient reabsorption status of main tree species in mountainous areas of east Liaoning, four secondary tree species were selected: Quercus mongolica, Acer mono, Juglans mandshurica, Fraxinus rhynchophylla and plantation deciduous (Larix spp.), The concentrations of total nitrogen (N), total phosphorus (P) and total potassium (K) in leaves before litter (litter) before and after litter were measured, and the nutrient reabsorption feature. The results showed that the concentration of N, P and K in litter of tested tree species was significantly lower than that of mature leaf (Larix K was not significant). The N reabsorption rate of Juglans mandshurica was significantly different from that of Quercus mongolica, There were significant differences in P reabsorption rate between Quercus mongolica and Quercus mongolica, and the K reuptake rate of Quercus mongolica was significantly different from that of Quercus mongolica, Juglans mandshurica and Fraxinus mandshurica (P <0.05). Generally, N, P, K The reabsorption rate was lower than the secondary forest species, especially the P reabsorption rate was significantly lower than that of the Fraxinus mandshurica, K reabsorption rate was significantly lower than Juglans manshurica and Fraxinus mandshurica (P <0.05). The above results show that larch improves the nutrient availability of soil by reducing the nutrient reabsorption rate and increasing the nutrient input of litter.