Regulatory effects of root pruning on leaf nutrients, photosynthesis, and growth of trees in a closed-canopy poplar plantation.

A plantation of 5-year-old poplar Populus × euramericana cv. 'Neva' was used to study the regulatory effects of root pruning on nutrients, photosynthetic characteristics, and water-use efficiency (WUE) of leaves and growth rates of diameter at breast height (DBH; 1.3 m), tree height, and volume.

Effects of root pruning on the physicochemical properties and microbial activities of poplar rhizosphere soil.

This study aimed to determine the effects of root pruning on the physicochemical characteristics and microbial activities of poplar rhizosphere soil. The root systems of 5-year-old poplar (Populus×euramericana cv. 'Neva') trees were manually pruned at 6, 8, or 10 times diameter at breast height (DBH) from the trunk (severe, moderate, and light, respectively) along both inter-row sides.

[Effects of gel made by super absorbent polymers and urea on fine root growth and nitrogen use efficiency of Platycladus orientalis bareroot seedlings.].

A pot experiment including five treatments, i.e., CK (neither fertilizer nor super absorbent polymers), U (urea alone), S [super absorbent polymers (SAP) alone], SUM (SAP mixed with urea) and SUG (gel made of SAP and urea) was conducted to evaluate their effects on fine root morphological characteristics, fine root absorption area, fine root nitrogen metabolism and nitrogen use efficiency of Platycladus orientalis bareroot seedlings.

[Effects of drought stress on the growth, photosynthetic characteristics, and active oxygen metabolism of poplar seedlings].

A pot experiment was conducted to study the effects of different water treatments (normal irrigation, light drought, moderate drought, and severe drought) on the growth, gas exchange, chlorophyll fluorescence characteristics, and active oxygen metabolism of poplar ( Populus x euramericana cv. 'Neva') seedlings in the experimental nursery of Shandong Forestry Academy from April to October, 2011. As compared with those under normal irrigation, the growth of the seedling' s basal diameter under light, moderate, and severe drought stress decreased by 12.