| 1. |
- Ellsworth, D. S., et al.
(författare)
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Convergence in phosphorus constraints to photosynthesis in forests around the world
- 2022
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Phosphorus (P) limitation is pervasive in tropical forests. Here the authors analyse the dependence of photosynthesis on leaf N and P in tropical forests, and show that incorporating leaf P constraints in a terrestrial biosphere model enhances its predictive power. Tropical forests take up more carbon (C) from the atmosphere per annum by photosynthesis than any other type of vegetation. Phosphorus (P) limitations to C uptake are paramount for tropical and subtropical forests around the globe. Yet the generality of photosynthesis-P relationships underlying these limitations are in question, and hence are not represented well in terrestrial biosphere models. Here we demonstrate the dependence of photosynthesis and underlying processes on both leaf N and P concentrations. The regulation of photosynthetic capacity by P was similar across four continents. Implementing P constraints in the ORCHIDEE-CNP model, gross photosynthesis was reduced by 36% across the tropics and subtropics relative to traditional N constraints and unlimiting leaf P. Our results provide a quantitative relationship for the P dependence for photosynthesis for the front-end of global terrestrial C models that is consistent with canopy leaf measurements.
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| 2. |
- Smith, N. G., et al.
(författare)
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Global photosynthetic capacity is optimized to the environment
- 2019
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Ingår i: Ecology Letters. - : Wiley. - 1461-023X .- 1461-0248. ; 22:3, s. 506-517
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Tidskriftsartikel (refereegranskat)abstract
- Earth system models (ESMs) use photosynthetic capacity, indexed by the maximum Rubisco carboxylation rate (V-cmax), to simulate carbon assimilation and typically rely on empirical estimates, including an assumed dependence on leaf nitrogen determined from soil fertility. In contrast, new theory, based on biochemical coordination and co-optimization of carboxylation and water costs for photosynthesis, suggests that optimal V-cmax can be predicted from climate alone, irrespective of soil fertility. Here, we develop this theory and find it captures 64% of observed variability in a global, field-measured V-cmax dataset for C-3 plants. Soil fertility indices explained substantially less variation (32%). These results indicate that environmentally regulated biophysical constraints and light availability are the first-order drivers of global photosynthetic capacity. Through acclimation and adaptation, plants efficiently utilize resources at the leaf level, thus maximizing potential resource use for growth and reproduction. Our theory offers a robust strategy for dynamically predicting photosynthetic capacity in ESMs.
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| 3. |
- Forshage, Mattias, et al.
(författare)
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Description of the aberrant Leptopilina lasallei n. sp., with an updated phylogeny of Leptopilina Förster (Hymenoptera: Figitidae: Eucoilinae)
- 2020
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Ingår i: Journal of Natural History. - : Informa UK Limited. - 0022-2933 .- 1464-5262. ; 54, s. 565-583
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Tidskriftsartikel (refereegranskat)abstract
- In the search for native Asian parasitoids of Drosophila suzukii, the notorious spotted-wing Drosophila (SWD), an odd new species of Eucoilinae was discovered. Leptopilina lasallei sp. nov. is herein described and diagnosed relative to other eucoilines associated with drosophilid hosts. Morphologically, L. lasallei is somewhat aberrant within Leptopilina; phylogenetically, L. lasallei is sister group to the core Leptopilina. In the process of investigating L. lasallei, a de novo molecular phylogeny of Leptopilina was generated and is included here. The integrated approach used for the characterisation of L. lasallei, and the resulting phylogeny of Leptopilina, produced data useful to select parasitoid species for SWD biological control.
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| 4. |
- Malhi, Yadvinder, et al.
(författare)
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The variation of productivity and its allocation along a tropical elevation gradient : A whole carbon budget perspective
- 2017
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Ingår i: New Phytologist. - : Wiley. - 0028-646X .- 1469-8137. ; 214:3, s. 1019-1032
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Tidskriftsartikel (refereegranskat)abstract
- Summary: Why do forest productivity and biomass decline with elevation? To address this question, research to date generally has focused on correlative approaches describing changes in woody growth and biomass with elevation. We present a novel, mechanistic approach to this question by quantifying the autotrophic carbon budget in 16 forest plots along a 3300 m elevation transect in Peru. Low growth rates at high elevations appear primarily driven by low gross primary productivity (GPP), with little shift in either carbon use efficiency (CUE) or allocation of net primary productivity (NPP) between wood, fine roots and canopy. The lack of trend in CUE implies that the proportion of photosynthate allocated to autotrophic respiration is not sensitive to temperature. Rather than a gradual linear decline in productivity, there is some limited but nonconclusive evidence of a sharp transition in NPP between submontane and montane forests, which may be caused by cloud immersion effects within the cloud forest zone. Leaf-level photosynthetic parameters do not decline with elevation, implying that nutrient limitation does not restrict photosynthesis at high elevations. Our data demonstrate the potential of whole carbon budget perspectives to provide a deeper understanding of controls on ecosystem functioning and carbon cycling.
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| 5. |
- Wilkinson, M., et al.
(författare)
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Partitioned postseismic deformation associated with the 2009 Mw 6.3 L'Aquila earthquake surface rupture measured using a terrestrial laser scanner
- 2010
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Ingår i: Geophysical Research Letters. - 0094-8276 .- 1944-8007. ; 37, s. L10309-
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Tidskriftsartikel (refereegranskat)abstract
- Using 3D terrestrial laser scan (TLS) technology, we have recorded postseismic deformation on and adjacent to the surface rupture formed during the 6th April 2009 L'Aquila normal faulting earthquake (Mw 6.3). Using surface modeling techniques and repeated surveys 8-124 days after the earthquake, we have produced a 4D dataset of postseismic deformation across a 3 x 65 m area at high horizontal spatial resolution. We detected millimetre-scale movements partitioned between discrete surface rupture slip and development of a hangingwall syncline over 10's of meters. We interpret the results as the signal of shallow afterslip in the fault zone. We find 52% of the total postseismic hangingwall vertical motion occurs as deformation within 30 m of the surface rupture. The total postseismic vertical motions are approximately 50% that of the coseismic. We highlight the importance of quantifying partitioned postseismic contributions when applying empirical slip-magnitude datasets to infer palaeoearthquake magnitudes. Citation: Wilkinson, M., et al. (2010), Partitioned postseismic deformation associated with the 2009 Mw 6.3 L'Aquila earthquake surface rupture measured using a terrestrial laser scanner.
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