• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Agroforestry Systems >An integrated model for predicting maximum net photosynthetic rate of cocksfoot (Dactylis glomerata) leaves in silvopastoral systems
【24h】

An integrated model for predicting maximum net photosynthetic rate of cocksfoot (Dactylis glomerata) leaves in silvopastoral systems

机译：牧草系统中预测赤足（Dactylis glomerata）叶片最大净光合速率的综合模型

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Net light-saturated photosynthetic rate (Amax) of field grown cocksfoot (Dactylis glomerata L.) leaves in a radiata pine (Pinus radiata D. Don) silvopastoral system (Canterbury, New Zealand) was measured at different times under severe shade (85–95 µmol m–2 s–1 photosynthetic photon flux density, PPFD) and in full sunlight (1900 µmol m–2 s–1 PPFD). The aim was to integrate individual functions for Amax against air temperature (2 to 37 ºC), water status, expressed as pre-dawn leaf water potential (ψlp) (-0.01 to −1.6 MPa), herbage nitrogen (N) (1.5 to 5.9%), regrowth duration (20 to 60 days) and time under shade (1 to 180 min) into a multiplicative model. The highest Amax value obtained was 27.4 µmol CO2 m–2 s–1 in non-limiting conditions with full sunlight. This value was defined as standardised dimensionless Amaxs = 1 for comparison of factor effects. The canopy temperature of the cocksfoot sward was up to 7.4 ºC cooler than air temperature for plants under shade. Therefore, canopy temperature was used to predict Amax. The only interaction was between time under severe shade (5% of the open PPFD) and water stress (ψlp = −0.4 to −1.3 MPa) and this was included in the model. Validation of this model indicated 78% of the variation in Amax could be accounted for using these five factors by the addition of the interaction function. This model could be used to assist the prediction of pasture growth in silvopastoral systems through incorporation into a canopy photosynthesis model.
机译：在严重的条件下，在不同的时间测量了辐射松（Pinus radiata D. Don）林牧系统（Canterbury，New Zealand）中田间生长的鸡足（Dactylis glomerata L.）叶片的净光饱和光合速率（Amax）。阴影（85–95 µmol m–2 s–1 光合光子通量密度，PPFD）和日光充足（1900 µmol m–2 s–1 PPFD） 。目的是整合针对大气温度（2至37ºC），水状态（表示为黎明前叶片水势（ψlp）（-0.01至-1.6 MPa））的Amax 的各个功能，增施模型中的牧草氮（N）（1.5至5.9％），再生时间（20至60天）和阴凉时间（1至180分钟）。在充满阳光的非限制性条件下，获得的最高Amax 值为27.4 µmol CO2 m–2 s–1 。将该值定义为标准的无因次Amaxs = 1，以比较因素影响。遮荫下植物的鸡冠草冠层温度比气温低7.4ºC。因此，利用冠层温度来预测Amax 。唯一的交互作用是在严重阴影下（打开PPFD的5％）下的时间与水分胁迫（ψlp = -0.4至-1.3 MPa）之间的相互作用，并且这包括在模型中。该模型的验证表明，通过使用这五个因素，可以通过添加相互作用函数来解释Amax 的78％的变化。该模型可用于通过结合到冠层光合作用模型中来预测牧草牧系统中牧场的生长。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号