Field-scale variability in site conditions explain phenotypic plasticity in response to nitrogen source in Pinus radiata D. Don

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Author(s)
Gallart, Marta
Love, Jonathan
Meason, Dean F
Coker, Graham
Clinton, Peter W
Xue, Jianming
Jameson, Paula E
Klapste, Jaroslav
Turnbull, Matthew H
Griffith University Author(s)
Year published
2019
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Aims: Productivity of forest ecosystems is constrained by site resource availability and utilisation at an individual tree level. A better understanding of nitrogen (N) nutrition addition to forest ecosystems is critical for maintaining optimal plantation productivity, given the influence of an environment gradient, genetics, and their interactions.
Methods: We studied the aboveground growth response in a plantation setting of ten commercial P. radiata genotypes to N-fertilisation using three different N sources, and also assessed the effect of on-site environmental factors on this response. We compared, on equimolar basis, ...
View more >Aims: Productivity of forest ecosystems is constrained by site resource availability and utilisation at an individual tree level. A better understanding of nitrogen (N) nutrition addition to forest ecosystems is critical for maintaining optimal plantation productivity, given the influence of an environment gradient, genetics, and their interactions. Methods: We studied the aboveground growth response in a plantation setting of ten commercial P. radiata genotypes to N-fertilisation using three different N sources, and also assessed the effect of on-site environmental factors on this response. We compared, on equimolar basis, the effect of N-fertilisation with inorganic N (NH4NO3), organic N (L-arginine), and the two N sources combined (L-arginine:NO3−) to that of unfertilised trees on tree height, diameter, descriptors of microsite variability, and climate and seasonal information. After 2.5 years of fertilisation, genotype-specific variation in aboveground growth response to N sources were measured, and these were significantly influenced by field-scale heterogeneity. Results: Across P. radiata genotypes, trees treated with inorganic N forms showed suppressed growth compared to unfertilised trees, while trees fertilised with organic N (either alone or in combination with inorganic N) were not significantly different than the untreated controls. We provide evidence of significant interactions between N source and genotype, N source and cover as well as genotype and microsite variability affecting temporal trends in tree volume. Conclusions: We conclude that the comprehension of field-scale variability in soil properties and associated environmental variables is essential for understanding genotype performance as they are crucial determinants of intraspecific variation in response to N-fertilisation.
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View more >Aims: Productivity of forest ecosystems is constrained by site resource availability and utilisation at an individual tree level. A better understanding of nitrogen (N) nutrition addition to forest ecosystems is critical for maintaining optimal plantation productivity, given the influence of an environment gradient, genetics, and their interactions. Methods: We studied the aboveground growth response in a plantation setting of ten commercial P. radiata genotypes to N-fertilisation using three different N sources, and also assessed the effect of on-site environmental factors on this response. We compared, on equimolar basis, the effect of N-fertilisation with inorganic N (NH4NO3), organic N (L-arginine), and the two N sources combined (L-arginine:NO3−) to that of unfertilised trees on tree height, diameter, descriptors of microsite variability, and climate and seasonal information. After 2.5 years of fertilisation, genotype-specific variation in aboveground growth response to N sources were measured, and these were significantly influenced by field-scale heterogeneity. Results: Across P. radiata genotypes, trees treated with inorganic N forms showed suppressed growth compared to unfertilised trees, while trees fertilised with organic N (either alone or in combination with inorganic N) were not significantly different than the untreated controls. We provide evidence of significant interactions between N source and genotype, N source and cover as well as genotype and microsite variability affecting temporal trends in tree volume. Conclusions: We conclude that the comprehension of field-scale variability in soil properties and associated environmental variables is essential for understanding genotype performance as they are crucial determinants of intraspecific variation in response to N-fertilisation.
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Journal Title
Plant and Soil
Volume
443
Issue
1-2
Copyright Statement
© 2019 Springer Netherlands. This is an electronic version of an article published in Plant and Soil, 443, pages 353–368 (2019). Plant and Soil is available online at: http://link.springer.com/ with the open URL of your article.
Subject
Environmental sciences
Biological sciences
Agricultural, veterinary and food sciences
Science & Technology
Life Sciences & Biomedicine
Agronomy
Plant Sciences
Soil Science