水保所知识产出(1956---)知识库

The bottom-up effects of vegetation have been documented to be strong drivers of the soil
food web structure and functioning in temperate forests. However, how the forest type affects the
stability of the soil food web is not well known. In the Ziwuling forest region of the Loess Plateau,
we selected three typical forests, Pinus tabuliformis Carrière (PT), Betula platyphylla Sukaczev (BP), and
Quercus liaotungensis Koidz. (QL), to investigate the soil nematode community characteristics in the
dry (April) and rainy (August) season, and analyzed their relationships with the soil properties. The
results showed that the characteristics of the soil nematode communities and their seasonal variations
differed markedly among the forest types. Compared to P. tabuliformis (PT), the B. platyphylla (BP) and
Q. liaotungensis (QL) forests had higher plant diversity and more easily decomposed litters, which
were more effective for improving the soil resource availability, thus, leading to more beneficial effects
on the soil nematode community. In both the dry and rainy season, the soil nematode abundance was
the highest in the BP forest. The Shannon–Wiener diversity index (H’), Pielou’s evenness index (J’),
and nematode channel ratio index (NCR) were higher, while the Simpson dominance index (λ) and
plant parasite index (PPI) were lower, in the BP and QL forests compared with in the PT forest. From
the dry to rainy season, the total nematode abundance and the abundance of fungivores, bacterivores,
and omnivore-predators, significantly increased in the QL and PT forests, and the values of the
Wasilewska index (WI), maturity index (MI), H’, J’, λ , and NCR showed the most significant seasonal
variability in the PT forest, which were mainly driven by changes in the soil labile C and N and the
moisture content between the two seasons. Generally, the seasonal stability of the soil nematode
communities was the highest in the BP forest and the poorest in the PT forest, probably due to
variations in the plant diversity. Our results suggest the importance of tree species and diversity as
bottom-up regulating factors of the soil food web structure, function, and seasonal stability, which has
important implications for sustainable forest management in the Loess Plateau and other temperate
regions.