| This paper studied soil samples in the region of Xiaoliang water conservation station in China, and the naturally restored
forest around it. 32 indices on the mechanical, chemical, microbiological and enzyme activity properties were studied for soil from 9 different vegetation patterns at 45 observation points by laboratory soil testing, grey correlation analysis and comprehensive evaluation. The results showed that: (1)From the scores of the sample soil, the order of the soil fertility was: naturally restored forest>broad leaf forest >eucalyptus pine mixed forest>U6.31>W5.31>W5.34>W5.41>W5.44>bare land. (2) Through this method, the sample plots were categorized to 5 levels:
Level 1 (the best): the sample was naturally restored forest which provided higher soil fertility than planted forest; Level 5 (the worst): the sample plot was bare land, where there was no vegetation cover and showed very poor soil fertility. (3) The comprehensive evaluation of the sample soil fertility by grey correlation analysis was in excellent agreement with the real situation, which proved this method was applicable and useful. Therefore, eucalyptus could be used as pioneer forest to recover the bare land, but it was not suitable for long-term planting and cropping, which would result in degradation of soil fertility that was unfavorable for ecological restoration. If planting eucalyptus was
determined, the actions could be taken, such as changing the breed variety often, rotation of crops, mixing with broad-leaf forest, protecting undergrowth vegetation, detaining forest litter coverage, and so on, which would benefit the soil fertility. |
