Thinning Promotes Soil Phosphorus Bioavailability in Short-Rotation and High-Density <i>Eucalyptus grandis × E. urophylla</i> Coppice Plantation in Guangxi, Southern China

Abstract

Thinning can improve soil nutrient supply, but the effects of thinning on soil phosphorus (P) contents and bioavailable mechanisms in high-density and short-rotation Eucalyptus coppice forests are not well reported. Therefore, we conducted five intensities of thinning treatments, which were 83% (283 tree ha−1, T1), 66% (566 tree ha−1, T2), 50% (833 tree ha−1, T3), 33% (1116 tree ha−1, T4), and 0% (1665 tree ha−1) in a 2nd 6-year-old E. grandis × E. urophylla coppice plantation with 8 years as a rotation, investigated soil nutrient contents, microbial biomass, and extracellular enzyme activities of 0–20 and 20–40 cm soil layers after two years of thinning, and analyzed the relationship between available phosphorus (AP) and other indicators. The results showed that soil total phosphorus (TP) contents in 2nd Eucalyptus coppice plantations were lower than in native forest ecosystems, but T1 significantly increased (p p p Eucalyptus coppice forests.

Keywords

• <i>Eucalyptus</i> plantation
• thinning
• soil nutrients
• phosphorus bioavailability
• microbial biomass
• extracellular enzyme activities