Shapotou Desert Research and Experiment Station, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou, 730000, China.
New Phytol. 2014 Dec;204(4):924-31. doi: 10.1111/nph.12952. Epub 2014 Jul 31.
Climate change scenarios forecast increased aridity in large areas worldwide with potentially important effects on nutrient availability and plant growth. Plant nitrogen and phosphorus concentrations (plant [N] and [P]) have been used to assess nutrient limitation, but a comprehensive understanding of drought stress on plant [N] and [P] remains elusive. We conducted a meta-analysis to examine responses of plant [N] and [P] to drought manipulation treatments and duration of drought stress. Drought stress showed negative effects on plant [N] (-3.73%) and plant [P] (-9.18%), and a positive effect on plant N:P (+ 6.98%). Drought stress had stronger negative effects on plant [N] and [P] in the short term (< 90 d) than in the long term (> 90 d). Drought treatments that included drying-rewetting cycles showed no effect on plant [N] and [P], while constant, prolonged, or intermittent drought stress had a negative effect on plant [P]. Our results suggest that negative effects on plant [N] and [P] are alleviated with extended duration of drought treatments and with drying-rewetting cycles. Availability of water, rather than of N and P, may be the main driver for reduced plant growth with increased long-term drought stress.
气候变化情景预测，全球大片地区将变得更加干燥，这可能对养分供应和植物生长产生重要影响。植物氮磷浓度（植物 [N] 和 [P]）已被用于评估养分限制，但对干旱胁迫对植物 [N] 和 [P] 的综合理解仍难以捉摸。我们进行了一项荟萃分析，以检验干旱处理和干旱胁迫持续时间对植物 [N] 和 [P] 的响应。干旱胁迫对植物 [N]（-3.73%）和植物 [P]（-9.18%）产生负面影响，对植物 N:P（+6.98%）产生积极影响。与长期（>90 天）相比，短期（<90 天）干旱胁迫对植物 [N] 和 [P] 的负面影响更大。包括干湿循环的干旱处理对植物 [N] 和 [P] 没有影响，而持续、延长或间歇性干旱胁迫对植物 [P] 有负面影响。我们的研究结果表明，延长干旱处理时间和干湿循环可以减轻植物 [N] 和 [P] 的负面影响。随着长期干旱胁迫的增加，水的可用性，而不是 N 和 P 的可用性，可能是植物生长减少的主要驱动因素。
