Nitrogen resorption and photosynthetic activity over leaf life span in an evergreen shrub, <i>Rhododendron ferrugineum</i>, in a subalpine environment

Pornon, André; Lamaze, Thierry

doi:10.1111/j.1469-8137.2007.02101.x

Cited by 23 publications

(19 citation statements)

References 42 publications

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“…The method provides reasonable estimates for the time of green-up; the green-up dates determined with this method are only 10-20 days after snowmelt. This estimate more or less agrees with the time of major leaf expansion (Marell et al 2006;Pornon and Lamaze 2007). White et al (2009) compared 10 methods for detecting green-up from RS and also found that method a (Midpoint pixel of White et al (2009)) was one of the only two that was well correlated to start of spring (SOS) measures and with a low bias.…”

Section: Discussionmentioning

confidence: 55%

Predicting the time of green up in temperate and boreal biomes

Kaduk

Los

2010

Climatic Change

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The referenced publication included a methodological error that affects a portion of the reported results for registered Democrats by about 1 percentage point on average.The original publication provides estimates of the distribution of public opinion among Republicans and Democrats. The estimates were constructed by combining survey data with US voter file data, census American Community Survey (ACS) data, and other data in a multilevel regression model. The voter file data are cross-tabulated counts of containing the number of American adults in different partisan and demographic subgroups and for each unique geographic area (i.e., states and congressional districts).Estimates for registered Democrats were in error because we mislabeled a subset of Democratic district-level voter file crosstabs at an early stage in the data preparation process. As a result, the subpopulation numbers for the Democratic opinion estimates were based on the number of Republicans in each demographic-geographic subtype Climatic Change (2018) 147:355-358 https://doi

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Section: Discussionmentioning

confidence: 55%

Predicting the time of green up in temperate and boreal biomes

Kaduk

Los

2010

Climatic Change

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“…Our results suggest that LLS is strongly influenced by the discrepancy between shoot nitrogen demand and soil nitrogen uptake, rather than nitrogen demand alone, as suggested by Hikosaka (2005). The reduction in LLS allows the plants to produce new leaves with high photosynthetic capacity (Pornon & Lamaze, 2007), revealing a plastic response that maximizes biomass production rather than nutrient conservation, even in nitrogen‐poor habitats. Altogether, our findings underline the major influence of sink organ development on the control of both LLS and NR, and the key role of woody tissues, firstly by supplying new shoots during the growing period and secondly by accumulating nitrogen from old foliage.…”

Section: Discussionmentioning

confidence: 99%

Endogenous sink–source interactions and soil nitrogen regulate leaf life‐span in an evergreen shrub

2009

Self Cite

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Summary• How the balance between exogenous and endogenous nitrogen for shoot growth varies with soil nitrogen availability, and its consequences on leaf life-span, have rarely been studied within a single species in the field.• In this study, we investigated two Rhododendron ferrugineum populations with contrasting leaf life-span. Soil nitrogen availability and nitrogen resorption of different leaf age classes were assessed, as were the interactions between plant compartments, using 15 N labelling and sink organ suppression.• The population growing on poorer soil had a shorter leaf life-span (17.9 vs 21.5 months) and a higher net contribution of leaf reserves to shoot growth (32% vs 15%), achieved by faster nitrogen resorption and greater shedding of young nitrogen-rich leaves. For both populations, wood contributed to over 40% of shoot nitrogen demand. Both the negative relationship between current-year shoot mass and the percentage of 1-yr-old attached leaves and the delay of leaf shedding after bud removal suggest that shoot development has a strong effect on leaf life-span.• Our results suggest that, contrary to the evolutionary response, plastic response to low soil nitrogen could reduce leaf life-span in evergreen plants. In addition, leaf life-span seems to be strongly influenced by the discrepancy between shoot nitrogen demand and soil nitrogen uptake rather than nitrogen demand alone.Abbreviations: ALx, attached/green leaves of the xth age cohort (0, 1, 2, 3 yr); DLx, dead/fallen leaves of the xth age cohort (0, 1, 2, 3 yr); LLS, leaf life-span (months); LMA, leaf mass area; MRT, mean residence time; N mass , nitrogen content [g (g DW −1 )]; NR, nitrogen resorption of ALx (g g −1 ); R EFF , nitrogen resorption efficiency (g g −1 ).

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“…SpeciWc leaf area is usually positively correlated with light use eYciency; thinner leaves require less photosynthetic machinery per unit area (Burns 2004), while thicker or denser leaves have greater internal shading and diVusion limitations, which may restrict the potential for higher photosynthetic capacity because of the chloroplast stacking in thick leaves (Reich et al 1998). In turn, low SLA foliage tends to be longer lived but less productive than thinner leaves (Pornon and Lamaze 2007), indicating a trade-oV between photosynthetic capacity and leaf persistence (Hikosaka 2004;Shipley et al 2006). Cost-beneWt models (Kikuzawa and Ackerley 1999;Wright et al 2004;Ellison 2006) suggest that better nutrient availability and shorter leaf life spans allow the plant to reinvest nutrients in young, photosynthetically active tissues, leading to higher PNUE.…”

Section: Photosynthetic Capacity and Foliar Chemistrymentioning

confidence: 97%

Effects of nutrient addition on leaf chemistry, morphology, and photosynthetic capacity of three bog shrubs

et al. 2011

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Plants in nutrient-poor environments typically have low foliar nitrogen (N) concentrations, long-lived tissues with leaf traits designed to use nutrients efficiently, and low rates of photosynthesis. We postulated that increasing N availability due to atmospheric deposition would increase photosynthetic capacity, foliar N, and specific leaf area (SLA) of bog shrubs. We measured photosynthesis, foliar chemistry and leaf morphology in three ericaceous shrubs (Vaccinium myrtilloides, Ledum groenlandicum and Chamaedaphne calyculata) in a long-term fertilization experiment at Mer Bleue bog, Ontario, Canada, with a background deposition of 0.8 g N m(-2) a(-1). While biomass and chlorophyll concentrations increased in the highest nutrient treatment for C. calyculata, we found no change in the rates of light-saturated photosynthesis (A(max)), carboxylation (V(cmax)), or SLA with nutrient (N with and without PK) addition, with the exception of a weak positive correlation between foliar N and A(max) for C. calyculata, and higher V(cmax) in L. groenlandicum with low nutrient addition. We found negative correlations between photosynthetic N use efficiency (PNUE) and foliar N, accompanied by a species-specific increase in one or more amino acids, which may be a sign of excess N availability and/or a mechanism to reduce ammonium (NH(4)) toxicity. We also observed a decrease in foliar soluble Ca and Mg concentrations, essential minerals for plant growth, but no change in polyamines, indicators of physiological stress under conditions of high N accumulation. These results suggest that plants adapted to low-nutrient environments do not shift their resource allocation to photosynthetic processes, even after reaching N sufficiency, but instead store the excess N in organic compounds for future use. In the long term, bog species may not be able to take advantage of elevated nutrients, resulting in them being replaced by species that are better adapted to a higher nutrient environment.

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Nitrogen resorption and photosynthetic activity over leaf life span in an evergreen shrub, Rhododendron ferrugineum, in a subalpine environment

Cited by 23 publications

References 42 publications

Predicting the time of green up in temperate and boreal biomes

Predicting the time of green up in temperate and boreal biomes

Endogenous sink–source interactions and soil nitrogen regulate leaf life‐span in an evergreen shrub

Effects of nutrient addition on leaf chemistry, morphology, and photosynthetic capacity of three bog shrubs

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