Relationship between stand volume and stand age in <i>P</i>. <i>deltoides</i> plantation in Zhoushan Forestry Farm, Jiangsu, China.

<p>Error bars represent standard error (SE).</p

Current annual increment and mean annual increment of stand volume of <i>P</i>. <i>deltoides</i> plantation at Zhoushan Forestry Farm, Jiangsu, China.

<p>Error bars represent standard error (SE).</p

Nutrient use efficiency of poplar and several plantation tree species in southern China.

<p>^a Cutting age of plantations in China are as follows: poplar, 12–15 years; Chinese fir, 25–30 years; <i>Eucalyptus</i>, 5–10 years; <i>Pinus massoniana</i>, 30–40 years; <i>Acacia mangium</i>, 10–15 years.</p><p>^b NUE1 = aboveground biomass of trees (t)/nutrient content (kg) in aboveground parts of trees.</p><p>^c NUE2 = stemwood biomass of trees (t)/nutrient content (kg) in tree stemwood.</p><p>Nutrient use efficiency of poplar and several plantation tree species in southern China.</p

Nutrient cycling of aboveground poplar and Chinese fir at different maturity stages.

<p>^aAnnual nutrient increment + annual nutrient return</p><p>^b∑ (annual biomass increment of each poplar tissue × nutrient concentration of each tissue)</p><p>^c∑ (aboveground litterfall biomass of poplar of each month in the stand × nutrient concentration in litterfall of each month)</p><p>^d(annual nutrient return / annual nutrient uptake) ×100%; ^e data are from Sheng and Fan (2005).</p><p>Nutrient cycling of aboveground poplar and Chinese fir at different maturity stages.</p