Litterfall and Nutrient Cycling of Eucalyptus Plantation with Different Ages on Leizhou Peninsula

Abstract:

In order to understand the changes in litterfall and nutrient cycling of Eucalyptus urophylla×E. grandis plantations with different ages on Leizhou Peninsula, the litterfall amount and nutrient return of Eucalyptus plantations with different ages were surveyed continued for 12 months. The results showed that the annual contents of litterfall of Eucalyptus plantations were in the order of 5 a > 9 a > 7 a, the total litterfall of 5 a plantation was significantly higher than that of 7 a and 9 a plantations, but there was no significant difference between later plantations. The litterfall contents of Eucalyptus plantations with different ages showed obvious seasonal changes with bimodal pattern, and the peak values appeared in the early or late rainy season. There was no significant correlation between forest structure factors and amount of litterfall, but there was a significant positive correlation between the monthly average temperature and litterfall amount. The annual nutrient flux of different forest ages was dominated by amount of litterfall and nutrient content. The annual nutrient flux of nitrogen, phosphorus and potassium in Eucalyptus plantations was in the order of 9 a > 7 a > 5 a, and there were significant differences among them. The peak period of nutrient restitution was concentrated around the rainy season, while the amount of nutrient restitution in winter was low. Therefore, in order to increase the yield of Eucalyptus plantation and facilitate the recovery of plantation soil fertility, the planting years of Eucalyptus plantation should be increased and the cutting season should be in winter.

Key words:Eucalyptus urophylla×E.grandis;Forest age;Litterfall;Nutrient restitution