The tiny giant of the sea, Ostreococcus's unique adaptations.
Foresi, N., De Marco, M. A., Del Castello, F., Ramirez, L., Nejamkin, A., Calo, G., Grimsley, N., Correa-Aragunde, N., & Martínez-Noël, G. M. A.
Plant Physiology and Biochemistry, 211: 108661. June 2024.
Paper
doi
link
bibtex
abstract
@article{foresi_tiny_2024,
title = {The tiny giant of the sea, \textit{{Ostreococcus}'s} unique adaptations},
volume = {211},
issn = {0981-9428},
url = {https://www.sciencedirect.com/science/article/pii/S0981942824003292},
doi = {10.1016/j.plaphy.2024.108661},
abstract = {Ostreococcus spp. are unicellular organisms with one of the simplest cellular organizations. The sequencing of the genomes of different Ostreococcus species has reinforced this status since Ostreococcus tauri has one most compact nuclear genomes among eukaryotic organisms. Despite this, it has retained a number of genes, setting it apart from other organisms with similar small genomes. Ostreococcus spp. feature a substantial number of selenocysteine-containing proteins, which, due to their higher catalytic activity compared to their selenium-lacking counterparts, may require a reduced quantity of proteins. Notably, O. tauri encodes several ammonium transporter genes, that may provide it with a competitive edge for acquiring nitrogen (N). This characteristic makes it an intriguing model for studying the efficient use of N in eukaryotes. Under conditions of low N availability, O. tauri utilizes N from abundant proteins or amino acids, such as L-arginine, similar to higher plants. However, the presence of a nitric oxide synthase (L-arg substrate) sheds light on a new metabolic pathway for L-arg in algae. The metabolic adaptations of O. tauri to day and night cycles offer valuable insights into carbon and iron metabolic configuration. O. tauri has evolved novel strategies to optimize iron uptake, lacking the classic components of the iron absorption mechanism. Overall, the cellular and genetic characteristics of Ostreococcus contribute to its evolutionary success, making it an excellent model for studying the physiological and genetic aspects of how green algae have adapted to the marine environment. Furthermore, given its potential for lipid accumulation and its marine habitat, it may represent a promising avenue for third-generation biofuels.},
urldate = {2024-05-17},
journal = {Plant Physiology and Biochemistry},
author = {Foresi, Noelia and De Marco, María Agustina and Del Castello, Fiorella and Ramirez, Leonor and Nejamkin, Andres and Calo, Gonzalo and Grimsley, Nigel and Correa-Aragunde, Natalia and Martínez-Noël, Giselle M. A.},
month = jun,
year = {2024},
keywords = {Alga, Iron, Lipids-starch, Mamiellales, Mamiellophyceae, Nitrogen, Picoeukaryote, Picophytoplankton},
pages = {108661},
}
Ostreococcus spp. are unicellular organisms with one of the simplest cellular organizations. The sequencing of the genomes of different Ostreococcus species has reinforced this status since Ostreococcus tauri has one most compact nuclear genomes among eukaryotic organisms. Despite this, it has retained a number of genes, setting it apart from other organisms with similar small genomes. Ostreococcus spp. feature a substantial number of selenocysteine-containing proteins, which, due to their higher catalytic activity compared to their selenium-lacking counterparts, may require a reduced quantity of proteins. Notably, O. tauri encodes several ammonium transporter genes, that may provide it with a competitive edge for acquiring nitrogen (N). This characteristic makes it an intriguing model for studying the efficient use of N in eukaryotes. Under conditions of low N availability, O. tauri utilizes N from abundant proteins or amino acids, such as L-arginine, similar to higher plants. However, the presence of a nitric oxide synthase (L-arg substrate) sheds light on a new metabolic pathway for L-arg in algae. The metabolic adaptations of O. tauri to day and night cycles offer valuable insights into carbon and iron metabolic configuration. O. tauri has evolved novel strategies to optimize iron uptake, lacking the classic components of the iron absorption mechanism. Overall, the cellular and genetic characteristics of Ostreococcus contribute to its evolutionary success, making it an excellent model for studying the physiological and genetic aspects of how green algae have adapted to the marine environment. Furthermore, given its potential for lipid accumulation and its marine habitat, it may represent a promising avenue for third-generation biofuels.
Diminishing legacy effects from forest fertilization on stand structure, vegetation community, and soil function.
Larsson, M., Strengbom, J., Gundale, M. J., & Nordin, A.
Forest Ecology and Management, 563: 121967. July 2024.
Paper
doi
link
bibtex
abstract
@article{larsson_diminishing_2024,
title = {Diminishing legacy effects from forest fertilization on stand structure, vegetation community, and soil function},
volume = {563},
issn = {0378-1127},
url = {https://www.sciencedirect.com/science/article/pii/S0378112724002792},
doi = {10.1016/j.foreco.2024.121967},
abstract = {While there is consensus that fertilization with nitrogen (N) is a cost-effective way of increasing both forest biomass yield and timber harvest profitability, the strength and longevity of legacy effects are debated. To quantify legacy effects of past fertilization, we analysed 21 mixed Pinus sylvesteris and Picea abies stands. The stands, on average 23 years old at the time of this study, were either unfertilized (n=7), fertilized with 150 kg N ha−1 once 36 years ago (n=7), or twice, 45 and 36 years ago, respectively (n=7), during the previous stand rotation. We performed measurements on soil N mineralisation and N availability, forest growth, ground vegetation community composition, soil and vegetation C/N ratios and soil C and N stocks, many of which responded to legacy N fertilization earlier in stand development. Our results show that the legacy effects of fertilization during the previous stand rotation have diminished through time, indicating an eventual convergence of stand properties. Specifically, all significant effects present in the previous measurement period (over a decade ago), were weaker or completely absent in the current study (i.e. 36 years after fertilization and 23 years after initiation of the new stands). None-the-less, this indicates a longer legacy effect of N fertilization than what is normally considered and suggests that care should be taken to mitigate unwanted, long-term effects when utilizing N addition to promote tree growth in boreal forests.},
urldate = {2024-05-15},
journal = {Forest Ecology and Management},
author = {Larsson, Marcus and Strengbom, Joachim and Gundale, Michael J. and Nordin, Annika},
month = jul,
year = {2024},
keywords = {Forest fertilization, Forest growth, Ion-exchange resin, Mineralization, Soil organic carbon, Vegetation community composition},
pages = {121967},
}
While there is consensus that fertilization with nitrogen (N) is a cost-effective way of increasing both forest biomass yield and timber harvest profitability, the strength and longevity of legacy effects are debated. To quantify legacy effects of past fertilization, we analysed 21 mixed Pinus sylvesteris and Picea abies stands. The stands, on average 23 years old at the time of this study, were either unfertilized (n=7), fertilized with 150 kg N ha−1 once 36 years ago (n=7), or twice, 45 and 36 years ago, respectively (n=7), during the previous stand rotation. We performed measurements on soil N mineralisation and N availability, forest growth, ground vegetation community composition, soil and vegetation C/N ratios and soil C and N stocks, many of which responded to legacy N fertilization earlier in stand development. Our results show that the legacy effects of fertilization during the previous stand rotation have diminished through time, indicating an eventual convergence of stand properties. Specifically, all significant effects present in the previous measurement period (over a decade ago), were weaker or completely absent in the current study (i.e. 36 years after fertilization and 23 years after initiation of the new stands). None-the-less, this indicates a longer legacy effect of N fertilization than what is normally considered and suggests that care should be taken to mitigate unwanted, long-term effects when utilizing N addition to promote tree growth in boreal forests.
Effects of Planting Position, Seedling Size, and Organic Nitrogen Fertilization on the Establishment of Scots Pine (Pinus sylvestris L.) and Norway Spruce (Picea abies (L.) Karst) Seedlings.
Häggström, B., Hajek, J., Nordin, A., & Öhlund, J.
Forests, 15(4): 703. April 2024.
Number: 4 Publisher: Multidisciplinary Digital Publishing Institute
Paper
doi
link
bibtex
abstract
@article{haggstrom_effects_2024,
title = {Effects of {Planting} {Position}, {Seedling} {Size}, and {Organic} {Nitrogen} {Fertilization} on the {Establishment} of {Scots} {Pine} ({Pinus} sylvestris {L}.) and {Norway} {Spruce} ({Picea} abies ({L}.) {Karst}) {Seedlings}},
volume = {15},
copyright = {http://creativecommons.org/licenses/by/3.0/},
issn = {1999-4907},
url = {https://www.mdpi.com/1999-4907/15/4/703},
doi = {10.3390/f15040703},
abstract = {The forest regeneration phase in Sweden commonly involves mechanical soil preparation followed by the planting of Scots pine (Pinus sylvestris L.) or Norway spruce (Picea abies (L.) Karst) seedlings. The prepared soil offers planting positions with different properties, including reduced damage by pine weevils (Hylobius abietis L.). Nitrogen fertilization can be applied at the time of planting to aid establishment of the seedlings. In this study, we compared the effects of different planting positions, organic nitrogen fertilization, and different seedling sizes on the early survival and growth of Scots pine and Norway spruce seedlings. The main planting positions were capped mound, hinge, and mineral soil. Seedlings planted close to organic material were categorized as being in “low-quality positions”, since proximity to organic material increases pine weevil attraction. Higher mortality rates related to pine weevil damage were recorded for the seedlings planted in the low-quality positions, regardless of seedling size or N fertilization. Pine weevil attack rates increased with increasing seedling size. Growth was, in general, lowest in the mineral soil positions. The effect of organic N fertilization on growth was positive for the spruce regardless of the planting position or seedling size, while it depended on the planting position and seedling size for the pine, indicating that the effects of organic N fertilization depend on the seedling species, seedling size, and planting position.},
language = {en},
number = {4},
urldate = {2024-05-10},
journal = {Forests},
author = {Häggström, Bodil and Hajek, Jörgen and Nordin, Annika and Öhlund, Jonas},
month = apr,
year = {2024},
note = {Number: 4
Publisher: Multidisciplinary Digital Publishing Institute},
keywords = {Norway spruce, Scots pine, forest regeneration, organic N fertilization, pine weevil, planting position, seedling size},
pages = {703},
}
The forest regeneration phase in Sweden commonly involves mechanical soil preparation followed by the planting of Scots pine (Pinus sylvestris L.) or Norway spruce (Picea abies (L.) Karst) seedlings. The prepared soil offers planting positions with different properties, including reduced damage by pine weevils (Hylobius abietis L.). Nitrogen fertilization can be applied at the time of planting to aid establishment of the seedlings. In this study, we compared the effects of different planting positions, organic nitrogen fertilization, and different seedling sizes on the early survival and growth of Scots pine and Norway spruce seedlings. The main planting positions were capped mound, hinge, and mineral soil. Seedlings planted close to organic material were categorized as being in “low-quality positions”, since proximity to organic material increases pine weevil attraction. Higher mortality rates related to pine weevil damage were recorded for the seedlings planted in the low-quality positions, regardless of seedling size or N fertilization. Pine weevil attack rates increased with increasing seedling size. Growth was, in general, lowest in the mineral soil positions. The effect of organic N fertilization on growth was positive for the spruce regardless of the planting position or seedling size, while it depended on the planting position and seedling size for the pine, indicating that the effects of organic N fertilization depend on the seedling species, seedling size, and planting position.