|کد مقاله||کد نشریه||سال انتشار||مقاله انگلیسی||ترجمه فارسی||نسخه تمام متن|
|6459158||1421354||2017||8 صفحه PDF||سفارش دهید||دانلود رایگان|
- Interactive effects of N fertilization and salinity on tree seedling growth were studied.
- N fertilization increased net photosynthetic rates and foliar N concentrations under low salinity.
- N fertilization improved seedling height and diameter growth under low salinity.
- N fertilization mitigates salinity effects on seedling growth species-specifically.
The effectiveness of nitrogen (N) fertilization in improving tree growth in saline forest soils is poorly understood. Hence, in this study, the interactive effect of N fertilization and salt stress on seedling physiology and growth was examined to improve our understanding of possible mechanisms for fertilization to mitigate salt stress. We compared physiological characteristics, growth, and foliar and root nutrient concentrations in lodgepole pine (Pinus contorta) and white spruce (Picea glauca) seedlings planted in a peat-mineral soil mix during a three months study with N fertilization (0 and 300Â mgÂ N seedlingâ1) and salinity (0, 50, 100, 150Â mmolÂ Lâ1 NaCl) in a greenhouse experiment. Nitrogen fertilization significantly increased net photosynthetic rates (Pn) and N concentrations in needles and roots, resulting in improved seedling height and root collar diameter growth and total seedling biomass for both species when seedlings were subjected to low salinity (50Â mmolÂ Lâ1 NaCl), while it did not help tree growth under high salinity (150Â mmolÂ Lâ1 NaCl). The physiological responses to combined salt stress and N fertilization did not differ between the two species; however, fertilization improved the growth of pine seedlings more than that of spruce seedlings under different salinity levels. The results suggest that the effectiveness of N fertilization in mitigating the salinity effect on seedling growth was species specific. Our study demonstrates that N fertilization improves tree growth through enhanced photosynthesis and N nutrition under low salinity and provides valuable insights into strategies to manage N nutrition in saline boreal forest soils.
Journal: Forest Ecology and Management - Volume 404, 15 November 2017, Pages 197-204