Huang Wenjuan, Zhou Guoyi, Liu Juxiu, Zhang Deqiang, Liu Shizhong, Chu Guowei, Fang Xiong
Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Tianhe District, Guangzhou, 510650, China.
Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Tianhe District, Guangzhou, 510650, China; Graduate University of Chinese Academy of Sciences, Beijing, 100049, China.
PLoS One. 2015 Mar 20;10(3):e0120190. doi: 10.1371/journal.pone.0120190. eCollection 2015.
Mineral elements in plants have been strongly affected by increased atmospheric carbon dioxide (CO2) concentrations and nitrogen (N) deposition due to human activities. However, such understanding is largely limited to N and phosphorus in grassland. Using open-top chambers, we examined the concentrations of potassium (K), calcium (Ca), magnesium (Mg), aluminum (Al), copper (Cu) and manganese (Mn) in the leaves and roots of the seedlings of five subtropical tree species in response to elevated CO2 (ca. 700 μmol CO2 mol(-1)) and N addition (100 kg N ha(-1) yr(-1)) from 2005 to 2009. These mineral elements in the roots responded more strongly to elevated CO2 and N addition than those in the leaves. Elevated CO2 did not consistently decrease the concentrations of plant mineral elements, with increases in K, Al, Cu and Mn in some tree species. N addition decreased K and had no influence on Cu in the five tree species. Given the shifts in plant mineral elements, Schima superba and Castanopsis hystrix were less responsive to elevated CO2 and N addition alone, respectively. Our results indicate that plant stoichiometry would be altered by increasing CO2 and N deposition, and K would likely become a limiting nutrient under increasing N deposition in subtropics.
由于人类活动导致的大气二氧化碳（CO₂）浓度增加和氮（N）沉降，植物中的矿质元素受到了强烈影响。然而，这种认识在很大程度上仅限于草原中的氮和磷。我们使用开顶式气室，研究了2005年至2009年期间，5种亚热带树种幼苗的叶片和根系中钾（K）、钙（Ca）、镁（Mg）、铝（Al）、铜（Cu）和锰（Mn）的浓度对升高的CO₂（约700 μmol CO₂ mol⁻¹）和施氮（100 kg N ha⁻¹ yr⁻¹）的响应。根系中的这些矿质元素对升高的CO₂和施氮的响应比叶片中的更强烈。升高的CO₂并没有持续降低植物矿质元素的浓度，一些树种的K、Al、Cu和Mn有所增加。施氮降低了5种树种中的K含量，对Cu没有影响。鉴于植物矿质元素的变化，木荷和红锥分别对单独升高的CO₂和施氮反应较小。我们的结果表明，增加CO₂和氮沉降会改变植物的化学计量，在亚热带地区，随着氮沉降的增加，钾可能会成为一种限制养分。
