1
|
Zheng J, She W, Zhang Y, Bai Y, Qin S, Wu B. Nitrogen enrichment alters nutrient resorption and exacerbates phosphorus limitation in the desert shrub Artemisia ordosica. Ecol Evol 2018; 8:9998-10007. [PMID: 30397442 PMCID: PMC6206216 DOI: 10.1002/ece3.4407] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 05/15/2018] [Accepted: 06/17/2018] [Indexed: 11/06/2022] Open
Abstract
Increasing nitrogen (N) deposition and precipitation are major drivers of global changes that are expected to influence plant nutrient resorption in desert ecosystems, where plant growth is often nutrient and water limited. However, knowledge on the effects of increased N and precipitation on them remain poorly understood. This study determined the effects of increased N (ambient, 60 kg N ha-1 year-1) and water supply (ambient, +20%, +40%), and their combination on the leaf nutrient resorption of Artemisia ordosica, a dominant shrub in the Mu Us Desert of northern China. After 2 years of treatments, only N addition significantly decreased the N resorption efficiency of A. ordosica. Both N and water addition had no effect on the phosphorus (P) resorption efficiency of this shrub, and there were no interactive effects of N and water availability on shrub nutrient resorption. The responses of shrub leaf N:P ratio tended to saturate as soil available N:P increased. The aboveground net primary productivity of A. ordosica was positively correlated with leaf P resorption efficiency, rather than N resorption efficiency. Our results suggest that N addition exacerbated the P limitation of the shrub growth and played a more fundamental role than water addition in controlling the nutrient resorption process of the desert shrub A. ordosica. This information contributes to understand the relationship between nutrient conservation strategy and plant growth of desert shrub species under global environmental changes.
Collapse
Affiliation(s)
- Jing Zheng
- School of Soil and Water ConservationBeijing Forestry UniversityBeijingChina
| | - Weiwei She
- School of Soil and Water ConservationBeijing Forestry UniversityBeijingChina
| | - Yuqing Zhang
- School of Soil and Water ConservationBeijing Forestry UniversityBeijingChina
- Key Laboratory of State Forestry Administration on Soil and Water ConservationBeijing Forestry UniversityBeijingChina
| | - Yuxuan Bai
- School of Soil and Water ConservationBeijing Forestry UniversityBeijingChina
| | - Shugao Qin
- School of Soil and Water ConservationBeijing Forestry UniversityBeijingChina
- Engineering Research Center of Forestry Ecological Engineering, Ministry of EducationBeijing Forestry UniversityBeijingChina
| | - Bin Wu
- School of Soil and Water ConservationBeijing Forestry UniversityBeijingChina
- Key Laboratory of State Forestry Administration on Soil and Water ConservationBeijing Forestry UniversityBeijingChina
| |
Collapse
|
2
|
Boutin M, Lamaze T, Couvidat F, Pornon A. Subalpine Pyrenees received higher nitrogen deposition than predicted by EMEP and CHIMERE chemistry-transport models. Sci Rep 2015; 5:12942. [PMID: 26255956 PMCID: PMC4530447 DOI: 10.1038/srep12942] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Accepted: 07/06/2015] [Indexed: 11/24/2022] Open
Abstract
Deposition of reactive nitrogen (N) from the atmosphere is expected to be the third greatest driver of biodiversity loss by the year 2100. Chemistry-transport models are essential tools to estimate spatially explicit N deposition but the reliability of their predictions remained to be validated in mountains. We measured N deposition and air concentration over the subalpine Pyrenees. N deposition was found to range from 797 to 1,463 mg N m(-2) year(-1). These values were higher than expected from model predictions, especially for nitrate, which exceeded the estimations of EMEP by a factor of 2.6 and CHIMERE by 3.6. Our observations also displayed a reversed reduced-to-oxidized ratio in N deposition compared with model predictions. The results highlight that the subalpine Pyrenees are exposed to higher levels of N deposition than expected according to standard predictions and that these levels exceed currently recognized critical loads for most high-elevation habitats. Our study reveals a need to improve the evaluation of N deposition in mountains which are home to a substantial and original part of the world's biodiversity.
Collapse
Affiliation(s)
- Marion Boutin
- Université Toulouse 3 Paul Sabatier, CNRS, ENFA, UMR5174 Laboratoire Evolution & Diversité Biologique, 118 route de Narbonne 31062 Toulouse Cedex 9, France
- Centre d’Etudes Spatiales de la BIOsphère, 31401 Toulouse Cedex 9, France
| | - Thierry Lamaze
- Centre d’Etudes Spatiales de la BIOsphère, 31401 Toulouse Cedex 9, France
| | - Florian Couvidat
- INERIS, Institut National de l’Environnement Industriel et des Risques, 60550 Verneuil-en-Halatte, France
| | - André Pornon
- Université Toulouse 3 Paul Sabatier, CNRS, ENFA, UMR5174 Laboratoire Evolution & Diversité Biologique, 118 route de Narbonne 31062 Toulouse Cedex 9, France
| |
Collapse
|
3
|
Marty C, Lamaze T, Pornon A. Leaf life span optimizes annual biomass production rather than plant photosynthetic capacity in an evergreen shrub. THE NEW PHYTOLOGIST 2010; 187:407-416. [PMID: 20497337 DOI: 10.1111/j.1469-8137.2010.03290.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
*Owing to nitrogen (N) translocation towards new leaves, the shedding of old leaves can increase the whole-plant carbon gain. It occurs when their photosynthetic nitrogen use efficiency (PNUE) declines below a given threshold. *Here, we investigated variations in net photosynthetic capacity (A(max)), N resorption and PNUE in populations of Rhododendron ferrugineum presenting different mean leaf life spans (LLS). *Both populations had comparable annual leaf surface area production and A(max) across leaf-age cohorts. Branch photosynthetic capacity was up to 95% higher in the population with the longer LLS mainly because of the high contribution of old leaves to the total leaf area. Despite lower N concentrations, old leaves maintained relatively high A(max) and consequently PNUE that were higher than or similar to the values found in current-year leaves. *As the ratio of PNUE in old to PNUE in new leaves was always higher than the fraction of leaf N resorbed during leaf shedding, we concluded that leaf shedding did not improve plant photosynthetic capacity. We suggest that in R. ferrugineum, leaf shedding is mainly controlled by the leaf storage function and, therefore, that models aiming to explain LLS should not only consider the leaf carbon assimilation function, particularly in nutrient-poor habitats.
Collapse
Affiliation(s)
- C Marty
- Environnement Canada, Centre Saint-Laurent, 105 rue McGill, Montréal, QC HEY 2E7, Canada
| | - T Lamaze
- Centre d'Etudes Spatiales de la Biosphère, CNES-CNRS-IRD-UMR 5639, Université Paul Sabatier, 18 Avenue Edouard Belin, bpi 2801, F-31401 Toulouse Cedex 4, France
| | - A Pornon
- Laboratoire Evolution et Diversité Biologique, CNRS-UMR 5174, Université Paul Sabatier, F-31062 Toulouse Cedex 4, France
| |
Collapse
|
4
|
Marty C, Pornon A, Escaravage N, Winterton P, Lamaze T. Complex interactions between a legume and two grasses in a subalpine meadow. AMERICAN JOURNAL OF BOTANY 2009; 96:1814-1820. [PMID: 21622302 DOI: 10.3732/ajb.0800405] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Interactions between plants are a complex combination of positive and negative interactions, with the net outcome depending on environmental contexts. The more frequent association of Trifolium alpinum (legume) with Festuca eskia than with Nardus stricta (grasses) in many Pyrenean subalpine meadows suggests a differential ability to use nitrogen (N) derived from N(2) fixation. In the field, we investigated the interactions between the legume and grasses and, in the glasshouse, the transfer of (15)N from the legume to the grasses. In one grass-Trifolium mixture, the legume had a strong positive effect on the biomass and N content of the grass as compared to pure grass stands. When both grasses grew together with the legume, only Festuca benefited from the presence of Trifolium but, surprisingly, the benefit decreased with increasing Trifolium abundance. Leaf labeling experiments with (15)N-NH(4)(+) revealed a higher transfer of (15)N from Trifolium to Festuca than to Nardus, suggesting a more direct N pathway between the two species. This more direct pathway could prevent Nardus from benefiting from the legume N in the three-species mixtures. Thus, the positive interactions between N-fixers and nonfixers appear to be largely species-specific and to depend strongly on the species in the plant assemblage.
Collapse
Affiliation(s)
- Charles Marty
- Laboratoire Evolution et Diversité Biologique, CNRS-UMR 5174, Université Paul Sabatier 31062, Toulouse cedex 4, France
| | | | | | | | | |
Collapse
|
5
|
Marty C, Lamaze T, Pornon A. Endogenous sink-source interactions and soil nitrogen regulate leaf life-span in an evergreen shrub. THE NEW PHYTOLOGIST 2009; 183:1114-1123. [PMID: 19500264 DOI: 10.1111/j.1469-8137.2009.02893.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
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.
Collapse
Affiliation(s)
- C Marty
- Laboratoire Evolution et Diversité Biologique, CNRS-UMR 5174, Université Paul Sabatier, 31062 Toulouse Cedex 4, France
- Centre d'Etudes Spatiales de la Biosphère, CNES-CNRS-IRD-UMR 5639, Université Paul Sabatier, 18 Avenue Edouard Belin, bpi 2801, 31401 Toulouse Cedex 4, France
| | - T Lamaze
- Centre d'Etudes Spatiales de la Biosphère, CNES-CNRS-IRD-UMR 5639, Université Paul Sabatier, 18 Avenue Edouard Belin, bpi 2801, 31401 Toulouse Cedex 4, France
| | - A Pornon
- Laboratoire Evolution et Diversité Biologique, CNRS-UMR 5174, Université Paul Sabatier, 31062 Toulouse Cedex 4, France
| |
Collapse
|
6
|
Pornon A, Lamaze T. Nitrogen resorption and photosynthetic activity over leaf life span in an evergreen shrub, Rhododendron ferrugineum, in a subalpine environment. THE NEW PHYTOLOGIST 2007; 175:301-310. [PMID: 17587378 DOI: 10.1111/j.1469-8137.2007.02101.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Here, the advantages for a shrub of having long vs short-lived leaves was investigated in Rhododendron ferrugineum by following nitrogen(15N) and carbon(14C) resorption and translocation, and photosynthetic capacity over the life span. Mean leaf life span was 19 months. Nitrogen (N) resorption in attached leaves occurred mainly in the first year (23%) and reached a maximum of 31% in the second. Although, resorption was similar in attached and fallen 1-yr-old leaves, it was on average one-third higher in fallen than in attached older leaves. Final N resorption of a leaf compartment reached 41%, half occurring from healthy leaves during the first year. Photosynthetic capacity decreased slightly during the life span. Before shoot growth, plant photosynthesis was mainly supported by 1-yr-old leaves, although the contribution of the 2-yr-old leaves was nonnegligible (15% of the capacity and higher carbon transfer toward the roots). After shoot growth, the current-year leaves made the greatest contribution. Our results suggest that short-lived leaves (half of the cohort) are mainly involved in a photosynthetic function, having a high photosynthetic capacity and drawing most of their resorbed N towards current-year leaves; and long-lived leaves are also involved in a conservative function, increasing N resorption and mean residence time (MRT).
Collapse
Affiliation(s)
- A Pornon
- Laboratoire Evolution et Diversité Biologique, CNRS-UMR 5174, Université Paul Sabatier, 31062 Toulouse cedex 4, France
| | - T Lamaze
- Centre d'Etudes Spatiales de la Biosphère, CNES-CNRS-IRD-UMR 5639, Université Paul Sabatier, 18 Avenue Edouard Belin, bpi 2801, 31401 Toulouse cedex 4, France
| |
Collapse
|
7
|
Michalet R. Highlighting the multiple drivers of change in interactions along stress gradients. THE NEW PHYTOLOGIST 2007; 173:3-6. [PMID: 17176387 DOI: 10.1111/j.1469-8137.2006.01949.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Affiliation(s)
- Richard Michalet
- University Bordeaux 1, Community Ecology Group, UMR INRA 1202 BIOGECO, Avenue des Facultés, 33405 Talence, France.
| |
Collapse
|
8
|
Milla R, Castro-Díez P, Maestro-Martínez M, Montserrat-Martí G. Relationships between phenology and the remobilization of nitrogen, phosphorus and potassium in branches of eight Mediterranean evergreens. THE NEW PHYTOLOGIST 2005; 168:167-78. [PMID: 16159331 DOI: 10.1111/j.1469-8137.2005.01477.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Few studies have examined the effects of plant growth on nutrient remobilization in phenologically contrasting species. Here we evaluated the consequences of above-ground seasonality of growth and leaf shedding on the remobilization of nutrients from branches in eight evergreen Mediterranean phanaerophytes that differ widely in phenology. Vegetative growth, flower bud formation, flowering, fruiting, leaf shedding, and the variations in nitrogen (N), phosphorus (P) and potassium (K) pools in branches throughout the year were monitored in each species. Nitrogen and P remobilization occurred in summer, after vegetative growth and synchronously with leaf shedding. Despite the time-lag between growth and remobilization, the branches that invested more nutrients in vegetative growth also remobilized more nutrients from their old organs. Potassium remobilization peaked in the climatically harshest periods, and appears to be related to osmotic requirements. We conclude that N and P remobilization occurs mainly associated with leaf senescence, which might be triggered by factors such as the replenishment of nutrient reserves in woody organs, the hormonal relations between new and old leaves, or the constraints that summer drought poses on the amount of leaf area per branch in summer.
Collapse
Affiliation(s)
- R Milla
- Instituto Pirenaico de Ecología (CSIC), PO Box 202, E-50080 Zaragoza, Spain.
| | | | | | | |
Collapse
|
9
|
Andresen LC, Michelsen A. Off-season uptake of nitrogen in temperate heath vegetation. Oecologia 2005; 144:585-97. [PMID: 15868162 DOI: 10.1007/s00442-005-0044-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2004] [Accepted: 02/02/2005] [Indexed: 11/27/2022]
Abstract
In this field study we show that temperate coastal heath vegetation has a significant off-season uptake potential for nitrogen, both in the form of ammonium and as glycine, throughout winter. We injected 15N-ammonium and 15N 2x(13C)-glycine into the soil twice during winter and once at spring. The winter temperatures were similar to those of an average winter in the northern temperate region of Europe, with only few days of soil temperatures below zero or above 5 degrees C. The vegetation, consisting of the evergreen dwarf shrub Calluna vulgaris, the deciduous dwarf shrub Salix arenaria, and the graminoids Carex arenaria and Deschampsia flexuosa, showed high root uptake of both forms of nitrogen, both 1 day after labelling and after a month, in species specific temporal patterns. Plant uptake of 13C was not significant, providing no further evidence of intact uptake of glycine. Translocation of the labelled nitrogen to shoots was generally evident after 1 month and increased as spring approached, with different translocation strategies in the three plant functional types. Furthermore, only the graminoids showed shoot growth during winter. Increasing plant nitrogen concentration from fall to spring at temperate heaths may, hence, be due to nitrogen uptake. Our results suggest that the potential for nitrogen uptake in plants at winter is of the same order of magnitude as at summer. Hence, winter nitrogen uptake in ecosystems in the temperate/boreal region should be considered when making annual nitrogen budgets of heath ecosystems, and the view of plant nutrient uptake as low in this climatic region during winter should be revised.
Collapse
Affiliation(s)
- Louise C Andresen
- Department of Terrestrial Ecology, Institute of Biology, University of Copenhagen, Øster Farimagsgade 2D, 1353, Copenhagen K, Denmark.
| | | |
Collapse
|