Abstract
Impacts of elevated tropospheric ozone and soil nitrogen amendment on two native European aspen ( Populus tremula L.) and eight hybrid aspen (P. tremula L. × Populus tremuloides Michx.) clones were studied in a free-air ozone exposure system. Potted saplings were exposed to ambient (ca. 20 ppb) or 1.5× ambient ozone and two levels of soil nitrogen (39 and 78 kg N·ha –1 ·year –1 in the first year, 60 and 140 kg N·ha –1 ·year –1 in the second year for low-nitrogen and high-nitrogen treatments, respectively) over two growing seasons. The plants were measured for photosynthesis, chlorophyll fluorescence, and biomass accumulation. Ozone decreased leaf-level net photosynthesis (A sat ) in particular early in the growing season and maximum quantum yield of photosystem II (F v /F m ) at the end of the growing season. Nitrogen amendment increased the growth of all plant parts and mitigated the adverse ozone effects. There were significant differences in ozone responses among the clones, and we were able to cluster the clones into sensitivity groups based on their growth responses. The most ozone-tolerant genotypes were hybrid aspen clones, indicating that populations that have already experienced selection for ozone-tolerant genotypes should be used to cross-breed with ozone-sensitive populations to achieve tolerance of a climate with increasing tropospheric ozone concentrations.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 8
Claim · model-written summary
Ozone decreased leaf-level net photosynthesis of aspen, particularly early in the growing season.
- Taxon
- Populus tremula
Populus tremulae0 - Treatment
- Ozonee3
- Outcome
- leaf-level net photosynthesise3
- Direction
- decreasede3
- Qualifier
- in particular early in the growing seasone3
- Comparator
- ambient (ca. 20 ppb)e2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Impacts of elevated tropospheric ozone and soil nitrogen amendment on two native European aspen ( Populus tremula L.) and eight hybrid aspen”
e2“Potted saplings were exposed to ambient (ca. 20 ppb) or 1.5× ambient ozone”
e3“Ozone decreased leaf-level net photosynthesis (A sat ) in particular early in the growing season and maximum quantum yield of photosystem II (F v /F m ) at the end of the growing season”
Claim · model-written summary
Ozone decreased maximum quantum yield of photosystem II of aspen at the end of the growing season.
- Taxon
- Populus tremulaPopulus tremulae0
- Treatment
- Ozonee3
- Outcome
- maximum quantum yield of photosystem IIe3
- Direction
- decreasede3
- Qualifier
- at the end of the growing seasone3
- Comparator
- ambient (ca. 20 ppb)e2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Impacts of elevated tropospheric ozone and soil nitrogen amendment on two native European aspen ( Populus tremula L.) and eight hybrid aspen”
e2“Potted saplings were exposed to ambient (ca. 20 ppb) or 1.5× ambient ozone”
e3“Ozone decreased leaf-level net photosynthesis (A sat ) in particular early in the growing season and maximum quantum yield of photosystem II (F v /F m ) at the end of the growing season”
Claim · model-written summary
Nitrogen amendment increased the growth of all plant parts of aspen.
- Taxon
- Populus tremulaPopulus tremulae0
- Treatment
- Nitrogen amendmente4
- Outcome
- growth of all plant partse4
- Direction
- increasede4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Impacts of elevated tropospheric ozone and soil nitrogen amendment on two native European aspen ( Populus tremula L.) and eight hybrid aspen”
e4“Nitrogen amendment increased the growth of all plant parts and mitigated the adverse ozone effects”
Claim · model-written summary
Nitrogen amendment mitigated the adverse effects of ozone on aspen.
- Taxon
- Populus tremulaPopulus tremulae0
- Treatment
- Nitrogen amendmente4
- Outcome
- adverse ozone effectse4
- Direction
- mitigatede4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Impacts of elevated tropospheric ozone and soil nitrogen amendment on two native European aspen ( Populus tremula L.) and eight hybrid aspen”
e4“Nitrogen amendment increased the growth of all plant parts and mitigated the adverse ozone effects”
Claim · model-written summary
Aspen clones differed significantly in their ozone responses.
- Taxon
- Populus tremulaPopulus tremulae0
- Material
- clonese5
- Outcome
- ozone responsese5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Impacts of elevated tropospheric ozone and soil nitrogen amendment on two native European aspen ( Populus tremula L.) and eight hybrid aspen”
e5“There were significant differences in ozone responses among the clones, and we were able to cluster the clones into sensitivity groups based on their growth responses”
Claim · model-written summary
Aspen clones were clustered into ozone sensitivity groups based on their growth responses.
- Taxon
- Populus tremulaPopulus tremulae0
- Outcome
- sensitivity groupse5
- Qualifier
- based on their growth responsese5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Impacts of elevated tropospheric ozone and soil nitrogen amendment on two native European aspen ( Populus tremula L.) and eight hybrid aspen”
e5“There were significant differences in ozone responses among the clones, and we were able to cluster the clones into sensitivity groups based on their growth responses”
Claim · model-written summary
The most ozone-tolerant aspen genotypes were hybrid aspen clones.
Verbatim
e6“The most ozone-tolerant genotypes were hybrid aspen clones, indicating that populations that have already experienced selection for ozone-tolerant genotypes should be used to cross-breed with ozone-sensitive populations to achieve tolerance of a climate with increasing tropospheric ozone concentrations”
Claim · model-written summary
Populations that have experienced selection for ozone-tolerant genotypes should be used to cross-breed with ozone-sensitive populations.
Verbatim
e6“The most ozone-tolerant genotypes were hybrid aspen clones, indicating that populations that have already experienced selection for ozone-tolerant genotypes should be used to cross-breed with ozone-sensitive populations to achieve tolerance of a climate with increasing tropospheric ozone concentrations”
The same questions in other papers
ozone · physiology: photosynthesis · Populus tremula (European aspen)Results agree
1 paper in the same direction as this paper
- negative
Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.