| 1. |
- Jankowski, Artur, et al.
(författare)
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Cold adaptation drives variability in needle structure and anatomy in Pinus sylvestris L. along a 1,900 km temperate-boreal transect
- 2017
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Ingår i: Functional Ecology. - : Wiley. - 0269-8463 .- 1365-2435. ; 31:12, s. 2212-2223
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Tidskriftsartikel (refereegranskat)abstract
- Occupancy of cold habitats by evergreen species requires structural modification of photosynthetic organs for stress resistance and longevity. Such modifications have been described at interspecific level, while intraspecific variation has been underexplored. To identify structural and anatomical traits that may be adaptive in cold environments, we studied intraspecific variability of needles of Scots pine (Pinus sylvestris L.), a wide-ranging tree, along a 1,900 km temperate-boreal transect in Europe. Needles from 20 sites representing mean minimum winter temperatures between -4.0 and -19.9°C and mean annual temperatures between 8.3 and -1.7°C were sampled for measurements of leaf mass per area (LMA, g/m2), leaf density (LD, g/cm3) and 30 other morpho-anatomical traits. Needles from cold sites lived longer, were shorter, showed higher LMA and LD, had narrower and more collapse-resistant tracheids, thicker epidermal cells with thicker cell walls and wider resin ducts occupying larger fraction of needle volume in comparison to needles from warmer sites. Along the steep climatic gradient, needles presented a coordinated phenotypic spectrum of external and internal traits that are largely interpretable in functional, adaptive terms. This intraspecific pattern of covarying traits provides insight into the adaptive syndrome associated with stress tolerance and extended needle longevity under cold conditions of high latitudes. A plain language summary is available for this article.
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| 2. |
- Mucha, Joanna, et al.
(författare)
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Fine root classification matters : nutrient levels in different functional categories, orders and diameters of roots in boreal Pinus sylvestris across a latitudinal gradient
- 2020
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Ingår i: Plant and Soil. - : Springer Science and Business Media LLC. - 0032-079X .- 1573-5036. ; 447:1-2, s. 507-520
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Tidskriftsartikel (refereegranskat)abstract
- Background: Fine roots and their symbionts are the key drivers of processes such as nutrient cycling and belowground productivity. Their function depends on position in a branching hierarchy, with absorptive roots (responsible for resource acquisition), and transport roots. Aim: We examined how the different diameter cutoffs for root classification mirror concentrations of 11 different nutrients, plus Al in functionally different fine roots of Pinus sylvestris based on anatomical/ functional categorization and in relation to their biomass along a latitudinal gradient. Results: The C:N:P ratios for pooled roots ≤2 mm in diameter reflected the nutrient concentrations of transport roots. In contrast, the C:N:P ratios for all absorptive roots was best reflected by nutrient ratios in the 1st root order, and not by those in root <2 mm. These patterns were more clear along decreasing mean annual temperature, despite increasing contribution of absorptive roots in the fine root biomass. Higher biomass fraction of transport roots did not always mirror higher concentration of element accumulated. Narrowing the root diameter cutoffs to 0.5 mm provided more informative data about nutrient concentrations in the absorptive root pool than <2 mm cut-off. Conclusions: By analyzing nutrient concentration using ≤2 mm cut-off it is impossible to properly understand nutritional properties of roots with different functional attributes. Given that the diameter of fine root orders vary considerably even within a single species between stands, the diameter cutoffs for absorptive roots should be based on the characteristics of the studied species, and not on a fixed, universal diameter cutoff.
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| 3. |
- Oleksyn, Jacek, et al.
(författare)
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A fingerprint of climate change across pine forests of Sweden
- 2020
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Ingår i: Ecology Letters. - : Wiley. - 1461-023X .- 1461-0248. ; 23:12, s. 1739-1746
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Tidskriftsartikel (refereegranskat)abstract
- Climate change has likely altered high-latitude forests globally, but direct evidence remains rare. Here we show that throughout a ≈1000-km transect in Scots pine (Pinus sylvestris L.) forests in Sweden, mature trees in ≈2015 had longer needles with shorter lifetimes than did trees in ≈1915. These century-scale shifts in needle traits were detected by sampling needles at 74 sites from 2012 to 2017 along the same transect where needle traits had been assessed at 57 sites in 1914–1915. Climate warming of ≈1 °C all along the transect in the past century has driven this temporal shift in foliage traits known to be physiologically critical to growth and carbon cycling processes. These century-scale changes in Scandinavian Scots pine forests represent a fingerprint of climate change on a fundamental biological element, the leaf, with repercussions for productivity and sensitivity to future climate, which are likely to be mirrored by similar changes for evergreen conifers across the boreal biome.
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