不同恢复模式亚热带森林土壤贮水量和养分储量的差异

Differences in soil water and nutrient storage in subtropical forests under different restoration modes

【目的】随着工业化进程加快,大量天然林遭到破坏,导致森林的数量和质量显著下降,因此采取了许多植被恢复措施,其主要方式有人工恢复和自然恢复模式。研究这两种不同恢复模式下林分的土壤贮水量和养分储量的差异,有助于比较这两种模式的优劣性,为亚热带植被恢复和重建提供理论依据。【方法】本研究选择九连山皆伐后自然恢复35年的次生林、人工栽植杉木后自然恢复39年的杉木林以及保存完好的原始林等3个典型林分为对象,比较不同恢复模式在水源涵养和养分贮存能力上的差异。【结果】研究结果表明:在贮水能力上,杉木林、次生林的吸持贮水量和饱和贮水量明显低于原始林,但在滞留贮水量上,杉木林、次生林却显著高于原始林,而杉木林和次生林在贮水量上较相似;在土壤养分贮存方面,原始林和次生林的速效氮储量均显著高于杉木林,但杉木林的有效磷储量显著高于次生林和原始林;原始林的碳储量、全氮储量和全磷储量均明显高于杉木林和次生林,且杉木林的碳储量、全氮储量显著高于次生林,但杉木林的全磷储量却显著低于次生林。【结论】两种恢复模式在土壤水源涵养方面相似,而在养分贮存能力上存在很大的差异,需要依据不同的生态恢复目标而选用不同的恢复模式,提高土壤速效氮和全磷储量宜采用自然恢复模式,提高土壤有效磷、碳储量和全氮储量宜采用人工恢复模式。

[Objective]With the acceleration of industrialization,many natural forests have been destroyed,leading to a significant decline in the quantity and quality of forests.Therefore,many measures have been taken to restore vegetation, mainly including artificial and natural restoration modes. Studying the differenceof soil water storage and nutrient storage of the forest under the two different restoration modes will help tocompare the advantages and disadvantages of these restoration modes, and provide a theoretical basis for thesubtropical vegetation restoration and reconstruction. [Method] In this study, three typical forests wereselected, including the secondary forest that had been naturally restored 35 years after precise cutting, theChinese fir forest that had been naturally restored 39 years after artificial planting, and the well preservedoriginal forest, to compare the differences of water conservation and nutrient storage capacity of variedrestoration modes. [Result] In terms of water storage capacity, the water holding capacity and saturatedwater storage capacity of Chinese fir forest and secondary forest were significantly lower than those of oldgrowthforest, but in terms of retained water storage capacity, Chinese fir forest and secondary forest wereconsiderably higher than the old-growth forest, while there was a similar water storage capacity betweenChinese fir forest and secondary forest. In terms of soil nutrient storage, the available nitrogen storage ofold-growth forest and secondary forest were significantly higher than those of Chinese fir forests, but theavailable phosphorus storage of Chinese fir forests was considerably higher than those of secondary and oldgrowthforests. The carbon, total nitrogen and total phosphorus storages of the old-growth forest weresignificantly higher than those of Chinese fir forest and secondary forest, and the carbon storage and totalnitrogen storage of Chinese fir forest were substantially higher than those of secondary forest, but the totalphosphorus storage of Chinese fir forest was significantly lower than those of secondary forest.[Conclusion] The two restoration modes are similar in soil water conservation but differ considerably innutrient storage capacity. Different restoration modes should be adopted according to the ecologicalrestoration objectives. The natural restoration mode should be used to improve available soil nitrogen andtotal phosphorus storage. The artificial restoration mode can be applied to improve nutrient storage ofavailable soil phosphorus, carbon, and total nitrogen.