Phosphorus and nitrogen limitations to photosynthesis in Rocky Mountain bristlecone pine (Pinas aristata) in Colorado
Phosphorus and nitrogen limitations to photosynthesis in Rocky Mountain bristlecone pine (Pinas aristata) in Colorado
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DOI：
10.1093/treephys/26.11.1477
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发表时间：
2006-11-01
期刊：
影响因子：
4
通讯作者：
Sanford, Robert L., Jr.
中科院分区：
文献类型：
--
作者：
Boyce, Richard L.;Larson, Jennifer R.;Sanford, Robert L., Jr.
我们研究了松aristata Engelm。矗立在科罗拉多的四个地点：阿尔马格雷山，黑山，歌利亚峰和石英维尔。所有看台都位于3200-3700英寸，面向东南偏南。我们测量了最大质量为基础的同化率（A（最大））和氮（N）和磷（P）的叶面浓度在6个叶龄级，从瞬时光合N-和P-利用效率（PNUE和PPUE，分别）和P：N比估计。叶质量单位面积（LMA）也被确定为每个叶龄级从每个站点。叶龄，P和N浓度，和P：N比解释了最大的变化时，从所有站点的数据相结合的A（最大）。叶质量单位面积没有变化，叶龄级。P和N都限制A（max），尽管P似乎更具限制性。临界P：N比约为0.12。黑山的结果与其他地点不同，因为A（max）与年龄无关，与LMA和P呈负相关。目前的研究结果表明，在Front Range地点没有N饱和的证据（Almagre Mountain和Goliath Peak）然而，由于磷是一种限制性营养素，在锋面山脉的某些地点，人为增加的氮的可利用性可能会对光合作用，也许还有生长，在未来
We examined Pinus aristata Engelm. stands in four locations in Colorado: Almagre Mountain, Black Mountain, Goliath Peak and Quartzville. All stands are located at 3200-3700 in and face south-southeast. We measured maximum mass-based assimilation rates (A(max)) and nitrogen (N) and phosphorus (P) foliar concentrations on six foliar age classes, from which instantaneous photosynthetic N- and P-use efficiencies (PNUE and PPUE, respectively) and P:N ratios were estimated. Leaf mass per area (LMA) was also determined for each foliar age class from each site.Foliar age, P and N concentrations, and the P:N ratio explained the most variation in A(max) when data from all sites were combined. Leaf mass per area did not vary with foliar age class. Both P and N limit A(max), although P appears to be more limiting. The critical P:N ratio is approximately 0.12. Results for Black Mountain differed from the other sites, as A(max) was not correlated with age and was negatively correlated with LMA and P. Current findings showed no evidence of N saturation at the Front Range sites (Almagre Mountain and Goliath Peak); however, because P is a limiting nutrient, increased anthropogenic N availability at sites in the Front Range may cause adverse effects on photosynthesis, and perhaps growth, in the future.