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

  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 difference of soil water storage and nutrient storage of the forest under the two different restoration modes will help to compare the advantages and disadvantages of these restoration modes, and provide a theoretical basis for the subtropical vegetation restoration and reconstruction.

  Method  In this study, three typical forests were selected, including the secondary forest that had been naturally restored 35 years after precise cutting, the Chinese fir forest that had been naturally restored 39 years after artificial planting, and the well preserved original forest, to compare the differences of water conservation and nutrient storage capacity of varied restoration modes.

  Result  In terms of water storage capacity, the water holding capacity and saturated water storage capacity of Chinese fir forest and secondary forest were significantly lower than those of old-growth forest, but in terms of retained water storage capacity, Chinese fir forest and secondary forest were considerably higher than the old-growth forest, while there was a similar water storage capacity between Chinese fir forest and secondary forest. In terms of soil nutrient storage, the available nitrogen storage of old-growth forest and secondary forest were significantly higher than those of Chinese fir forests, but the available phosphorus storage of Chinese fir forests was considerably higher than those of secondary and old-growth forests. The carbon, total nitrogen and total phosphorus storages of the old-growth forest were significantly higher than those of Chinese fir forest and secondary forest, and the carbon storage and total nitrogen storage of Chinese fir forest were substantially higher than those of secondary forest, but the total phosphorus 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 in nutrient storage capacity. Different restoration modes should be adopted according to the ecological restoration objectives. The natural restoration mode should be used to improve available soil nitrogen and total phosphorus storage. The artificial restoration mode can be applied to improve nutrient storage of available soil phosphorus, carbon, and total nitrogen.