Li Yu-lin, Mao Wei, Zhao Xue-yong, Zhang Tong-hui
Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China.
Huan Jing Ke Xue. 2010 Aug;31(8):1716-25.
Characteristics of leaf nitrogen and phosphorus stoichiometry at regional scale is key factors to understand spatial pattern, forecast change trends and reveal responses of terrestrial ecosystem to global change. In this study, pattern of leaf nitrogen and phosphorus of 214 plants was investigated to elucidate their relationships with rainfall and temperature in typical desert and desertified regions of northern China. The results showed that average leaf nitrogen concentration, average leaf phosphorus concentrations, and leaf N/P of 214 species are (24.45 +/- 8.1) mg/g, (1.74 +/- 0. 88) mg/g, 15.77 +/- 7.5 in these regions of northern China, respectively. Compared with other studies at global, national or regional scale, leaf nitrogen and phosphorus concentrations are significantly higher in this study (p < 0.001). However, leaf N/P didn't show any significant differences with other studies. This implies that leaf N/P is generally well-constrained. One-way ANOVA analysis showed that leaf N, P, and N/P varied significantly among trees, shrubs, graminoids, and forbs. Leaf N concentration in shrubs, forbs and leaf P concentration in forbs are averagely higher than those in other life-forms, respectively. This implies that nutrient use strategies are significantly different among plant life-forms. There are no significant differences in leaf nitrogen concentration among each typically desert and desertified region. However, Leaf phosphorus concentration and leaf N/P are significantly different among each typically desert and desertified regions. Leaf phosphorus concentrations are relatively high in Kerqin Sand Land and Mowuso Sand Land. Leaf N/P of most species in Talimu basin, Zhunger Basin, and Alashan is higher than 16, and lower than 14 of most species in Kerqin Sand land. This means that nutrient constraining in different regions varies greatly. Correlations analysis showed that leaf N, P, and N/P are significantly correlated with annual precipitation, but not significantly correlated with annual mean temperature in desert and desertified regions of northern China.
区域尺度上叶片氮磷化学计量特征是理解陆地生态系统空间格局、预测变化趋势以及揭示其对全球变化响应的关键因素。本研究调查了中国北方典型沙漠及沙漠化地区214种植物的叶片氮磷格局，以阐明它们与降雨和温度的关系。结果表明，中国北方这些地区214个物种的平均叶片氮浓度、平均叶片磷浓度和叶片N/P分别为(24.45±8.1)mg/g、(1.74±0.88)mg/g、15.77±7.5。与全球、国家或区域尺度的其他研究相比，本研究中叶片氮磷浓度显著更高(p<0.001)。然而，叶片N/P与其他研究没有显著差异。这意味着叶片N/P通常受到良好的限制。单因素方差分析表明，叶片N、P和N/P在乔木、灌木、禾本科植物和草本植物之间存在显著差异。灌木和草本植物的叶片N浓度以及草本植物的叶片P浓度平均分别高于其他生活型。这意味着不同植物生活型的养分利用策略存在显著差异。各典型沙漠和沙漠化地区之间叶片氮浓度没有显著差异。然而，各典型沙漠和沙漠化地区之间叶片磷浓度和叶片N/P存在显著差异。科尔沁沙地和毛乌素沙地的叶片磷浓度相对较高。塔里木盆地、准噶尔盆地和阿拉善地区大多数物种的叶片N/P高于16，而科尔沁沙地大多数物种的叶片N/P低于14。这意味着不同地区的养分限制差异很大。相关性分析表明，在中国北方沙漠及沙漠化地区，叶片N、P和N/P与年降水量显著相关，但与年平均温度没有显著相关性。
