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Paoletti E, Pagano M, Zhang L, Badea O, Hoshika Y. Allocation of Nutrients and Leaf Turnover Rate in Poplar under Ambient and Enriched Ozone Exposure and Soil Nutrient Manipulation. BIOLOGY 2024; 13:232. [PMID: 38666844 PMCID: PMC11048010 DOI: 10.3390/biology13040232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 03/27/2024] [Accepted: 03/29/2024] [Indexed: 04/28/2024]
Abstract
An excess of ozone (O3) is currently stressing plant ecosystems and may negatively affect the nutrient use of plants. Plants may modify leaf turnover rates and nutrient allocation at the organ level to counteract O3 damage. We investigated leaf turnover rate and allocation of primary (C, N, P, K) and secondary macronutrients (Ca, S, Mg) under various O3 treatments (ambient concentration, AA, with a daily hourly average of 35 ppb; 1.5 × AA; 2.0 × AA) and fertilization levels (N: 0 and 80 kg N ha-1 y-1; P: 0 and 80 kg N ha-1 y-1) in an O3-sensitive poplar clone (Oxford: Populus maximowiczii Henry × P. berolinensis Dippel) in a Free-Air Controlled Exposure (FACE) experiment. The results indicated that both fertilization and O3 had a significant impact on the nutrient content. Specifically, fertilization and O3 increased foliar C and N contents (+5.8% and +34.2%, respectively) and root Ca and Mg contents (+46.3% and +70.2%, respectively). Plants are known to increase the content of certain elements to mitigate the damage caused by high levels of O3. The leaf turnover rate was accelerated as a result of increased O3 exposure, indicating that O3 plays a main role in influencing this physiological parameter. A PCA result showed that O3 fumigation affected the overall allocation of primary and secondary elements depending on the organ (leaves, stems, roots). As a conclusion, such different patterns of element allocation in plant leaves in response to elevated O3 levels can have significant ecological implications.
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Affiliation(s)
- Elena Paoletti
- IRET-CNR, Via Madonna del Piano 10, Sesto Fiorentino, 50019 Florence, Italy; (E.P.); (Y.H.)
| | - Mario Pagano
- IRET-CNR, Via Madonna del Piano 10, Sesto Fiorentino, 50019 Florence, Italy; (E.P.); (Y.H.)
| | - Lu Zhang
- College of Landscape and Architecture, Zhejiang A&F University, 666 Wusu Street, Hangzhou 311300, China;
| | - Ovidiu Badea
- National Institute for Research and Development in Forestry ‘Marin Drăcea’, 128, Eroilor Bvd., 077190 Voluntari, Romania;
- Faculty of Silviculture and Forest Engineering, Transilvania University, 1, Ludwig van Beethoven Street, 500123 Brasov, Romania
| | - Yasutomo Hoshika
- IRET-CNR, Via Madonna del Piano 10, Sesto Fiorentino, 50019 Florence, Italy; (E.P.); (Y.H.)
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Bona KA, Shaw C, Thompson DK, Hararuk O, Webster K, Zhang G, Voicu M, Kurz WA. The Canadian model for peatlands (CaMP): A peatland carbon model for national greenhouse gas reporting. Ecol Modell 2020. [DOI: 10.1016/j.ecolmodel.2020.109164] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Prins AH, Berdowski JJM, Latuhihin MJ. Effect of NH4-fertilization on the maintenance of aCalluna vulgarisvegetation. ACTA ACUST UNITED AC 2015. [DOI: 10.1111/j.1438-8677.1991.tb01558.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- A. H. Prins
- Research Institute for Nature Management; P.O. Box 46 NL-3956 2R Leersum
| | - J. J. M. Berdowski
- TNO Institute of Environmental Sciences; Delft
- Research Institute for Nature Management; P.O. Box 46 NL-3956 2R Leersum
| | - M. J. Latuhihin
- Ministry of Transport and Public Works; Rijswijk The Netherlands
- Research Institute for Nature Management; P.O. Box 46 NL-3956 2R Leersum
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Hou E, Chen C, McGroddy ME, Wen D. Nutrient limitation on ecosystem productivity and processes of mature and old-growth subtropical forests in China. PLoS One 2012; 7:e52071. [PMID: 23284873 PMCID: PMC3527367 DOI: 10.1371/journal.pone.0052071] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Accepted: 11/15/2012] [Indexed: 11/29/2022] Open
Abstract
Nitrogen (N) is considered the dominant limiting nutrient in temperate regions, while phosphorus (P) limitation frequently occurs in tropical regions, but in subtropical regions nutrient limitation is poorly understood. In this study, we investigated N and P contents and N:P ratios of foliage, forest floors, fine roots and mineral soils, and their relationships with community biomass, litterfall C, N and P productions, forest floor turnover rate, and microbial processes in eight mature and old-growth subtropical forests (stand age >80 yr) at Dinghushan Biosphere Reserve, China. Average N:P ratios (mass based) in foliage, litter (L) layer and mixture of fermentation and humus (F/H) layer, and fine roots were 28.3, 42.3, 32.0 and 32.7, respectively. These values are higher than the critical N:P ratios for P limitation proposed (16-20 for foliage, ca. 25 for forest floors). The markedly high N:P ratios were mainly attributed to the high N concentrations of these plant materials. Community biomass, litterfall C, N and P productions, forest floor turnover rate and microbial properties were more strongly related to measures of P than N and frequently negatively related to the N:P ratios, suggesting a significant role of P availability in determining ecosystem production and productivity and nutrient cycling at all the study sites except for one prescribed disturbed site where N availability may also be important. We propose that N enrichment is probably a significant driver of the potential P limitation in the study area. Low P parent material may also contribute to the potential P limitation. In general, our results provided strong evidence supporting a significant role for P availability, rather than N availability, in determining ecosystem primary productivity and ecosystem processes in subtropical forests of China.
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Affiliation(s)
- Enqing Hou
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- Environmental Futures Centre, Griffith School of Environment, Griffith University, Nathan, Queensland, Australia
- University of Chinese Academy of Sciences, Beijing, China
| | - Chengrong Chen
- Environmental Futures Centre, Griffith School of Environment, Griffith University, Nathan, Queensland, Australia
| | - Megan E. McGroddy
- Department of Environmental Sciences, NASA/University of Virginia, Charlottesville, Virginia, United States of America
| | - Dazhi Wen
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
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Pornon A, Marty C, Winterton P, Lamaze T. The intriguing paradox of leaf lifespan responses to nitrogen availability. Funct Ecol 2011. [DOI: 10.1111/j.1365-2435.2011.01849.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Soil nutrient heterogeneity and competitive ability of three grass species (Festuca ovina, Arrhenatherum elatius and Calamagrostis epigejos) in experimental conditions. Biologia (Bratisl) 2009. [DOI: 10.2478/s11756-009-0067-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Hallik L, Niinemets Ü, Wright IJ. Are species shade and drought tolerance reflected in leaf-level structural and functional differentiation in Northern Hemisphere temperate woody flora? THE NEW PHYTOLOGIST 2009; 184:257-274. [PMID: 19674334 DOI: 10.1111/j.1469-8137.2009.02918.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Leaf-level determinants of species environmental stress tolerance are still poorly understood. Here, we explored dependencies of species shade (T(shade)) and drought (T(drought)) tolerance scores on key leaf structural and functional traits in 339 Northern Hemisphere temperate woody species. In general, T(shade) was positively associated with leaf life-span (L(L)), and negatively with leaf dry mass (M(A)), nitrogen content (N(A)), and photosynthetic capacity (A(A)) per area, while opposite relationships were observed with drought tolerance. Different trait combinations responsible for T(shade) and T(drought) were observed among the key plant functional types: deciduous and evergreen broadleaves and evergreen conifers. According to principal component analysis, resource-conserving species with low N content and photosynthetic capacity, and high L(L) and M(A), had higher T(drought), consistent with the general stress tolerance strategy, whereas variation in T(shade) did not concur with the postulated stress tolerance strategy. As drought and shade often interact in natural communities, reverse effects of foliar traits on these key environmental stress tolerances demonstrate that species niche differentiation is inherently constrained in temperate woody species. Different combinations of traits among key plant functional types further explain the contrasting bivariate correlations often observed in studies seeking functional explanation of variation in species environmental tolerances.
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Affiliation(s)
- Lea Hallik
- Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 1, Tartu EE-51014, Estonia
- Department of Botany, Institute of Ecology and Earth Sciences, University of Tartu, 40 Lai St, EE-51005 Tartu, Estonia
| | - Ülo Niinemets
- Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 1, Tartu EE-51014, Estonia
| | - Ian J Wright
- Department of Biological Sciences, Macquarie University, NSW 2109, Australia
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Nitrogen supply effects on leaf dynamics and nutrient input into the soil of plant species in a sub-arctic tundra ecosystem. Polar Biol 2008. [DOI: 10.1007/s00300-008-0521-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Oikawa S, Hikosaka K, Hirose T. Leaf lifespan and lifetime carbon balance of individual leaves in a stand of an annual herb, Xanthium canadense. THE NEW PHYTOLOGIST 2006; 172:104-16. [PMID: 16945093 DOI: 10.1111/j.1469-8137.2006.01813.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Leaf lifespan in response to resource availability has been documented in many studies, but it still remains uncertain what determines the timing of leaf shedding. Here, we evaluate the lifetime carbon (C) balance of a leaf in a canopy as influenced by nitrogen (N) availability. Stands of Xanthium canadense were established with high-nitrogen (HN) and low-nitrogen (LN) treatments and temporal changes of C gain of individual leaves were investigated with a canopy photosynthesis model. Daily C gain of a leaf was maximal early in its development and subsequently declined. Daily C gain at shedding was nearly zero in HN, while it was still positive in LN. Sensitivity analyses showed that the decline in the daily C gain resulted primarily from the reduction in light level in HN and by the reduction in leaf N in LN. Smaller leaf size in LN than in HN led to higher light levels in the canopy, which helped leaves of the LN stand maintain for a longer period. These results suggest that the mechanism by which leaf lifespan is determined changes depending on the availability of the resource that is most limiting to plant growth.
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Affiliation(s)
- Shimpei Oikawa
- Graduate School of Life Sciences, Tohoku University, 6-3 Aoba, Sendai 980-8578, Japan.
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Oikawa S, Hikosaka K, Hirose T. Dynamics of leaf area and nitrogen in the canopy of an annual herb, Xanthium canadense. Oecologia 2005; 143:517-26. [PMID: 15791424 DOI: 10.1007/s00442-005-0007-6] [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: 05/06/2004] [Accepted: 01/07/2005] [Indexed: 11/25/2022]
Abstract
We studied leaf area and nitrogen dynamics in the canopy of stands of an annual herb Xanthium canadense, grown at a high (HN)- and a low-nitorgen (LN) availability. Standing leaf area increased continuously through the vegetative growth period in the LN stand, or leveled off in the later stage in the HN stand. When scaled against standing leaf area, both production and loss rates of leaf area increased but with different patterns: the production rate was retarded, while the loss rate was accelerated, implying an upper limit of standing leaf area of the canopy. The rate of leaf-area production was higher in the HN than in the LN stand, which was caused by the higher rate of leaf production per standing leaf area as well as the greater standing leaf area in the HN stand. Although the rate of leaf-area loss was higher in the HN than in the LN stand, it was not significantly different between the two stands when compared at a common standing leaf area, suggesting involvement of light climate in determination of the leaf-loss rate. On the other hand, the rate of leaf-area loss was positively correlated with nitrogen demand for leaf area development across the two stands, suggesting that leaf loss was caused by retranslocation of nitrogen for construction of new leaves. A simple simulation model of leaf and nitrogen dynamics in the canopy showed that, at steady state, where the rate of leaf-area loss becomes equal to the production rate, the standing leaf area was still greater in the HN than in the LN stand. Similarly, when the uptake and loss of nitrogen are equilibrated, the standing nitrogen was greater in the HN than in the LN stand. These results suggest that leaf-area production is strongly controlled by nitrogen availability, while both nitrogen and light climate determine leaf-loss rates in the canopy.
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Affiliation(s)
- Shimpei Oikawa
- Graduate School of Life Sciences, Tohoku University, Aoba, Sendai, 980-8578, Japan.
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Güsewell S. N : P ratios in terrestrial plants: variation and functional significance. THE NEW PHYTOLOGIST 2004; 164:243-266. [PMID: 33873556 DOI: 10.1111/j.1469-8137.2004.01192.x] [Citation(s) in RCA: 780] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Nitrogen (N) and phosphorus (P) availability limit plant growth in most terrestrial ecosystems. This review examines how variation in the relative availability of N and P, as reflected by N : P ratios of plant biomass, influences vegetation composition and functioning. Plastic responses of plants to N and P supply cause up to 50-fold variation in biomass N : P ratios, associated with differences in root allocation, nutrient uptake, biomass turnover and reproductive output. Optimal N : P ratios - those of plants whose growth is equally limited by N and P - depend on species, growth rate, plant age and plant parts. At vegetation level, N : P ratios <10 and >20 often (not always) correspond to N- and P-limited biomass production, as shown by short-term fertilization experiments; however long-term effects of fertilization or effects on individual species can be different. N : P ratios are on average higher in graminoids than in forbs, and in stress-tolerant species compared with ruderals; they correlate negatively with the maximal relative growth rates of species and with their N-indicator values. At vegetation level, N : P ratios often correlate negatively with biomass production; high N : P ratios promote graminoids and stress tolerators relative to other species, whereas relationships with species richness are not consistent. N : P ratios are influenced by global change, increased atmospheric N deposition, and conservation managment. Contents Summary 243 I Introduction 244 II Variability of N : P ratios in response to nutrient supply 244 III Critical N : P ratios as indicators of nutrient limitation 248 IV Interspecific variation in N : P ratios 252 V Vegetation properties in relation to N : P ratios 255 VI Implications of N : P ratios for human impacts on ecosystems 258 VII Conclusions 259 Acknowledgements 259 References 260.
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Affiliation(s)
- Sabine Güsewell
- Geobotanical Institute ETH, Zürichbergstrasse 38, 8044 Zürich, Switzerland
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KNOPS JOHANNESMH, REINHART KURT. Specific Leaf Area Along a Nitrogen Fertilization Gradient. AMERICAN MIDLAND NATURALIST 2000. [DOI: 10.1674/0003-0031(2000)144[0265:slaaan]2.0.co;2] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Anderson WB, Eickmeier WG. Nutrient resorption in Claytonia virginica L.: implications for deciduous forest nutrient cycling. ACTA ACUST UNITED AC 2000. [DOI: 10.1139/b00-056] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
According to the vernal dam hypothesis, spring ephemeral herbs temporarily sequester large nutrient pools in deciduous forests prior to canopy closure and return the nutrients to the soil following senescence of aboveground tissues. However, many species resorb nutrients from their leaves back to belowground tissues during senescence, and the degree of resorption is often associated with soil nutrient availability. Species that store large proportions of their absorbed nutrients between years are not participating in the temporary sequestering and rapid recycling of nutrients implied by the vernal dam. We investigated the extent to which Claytonia virginica L. sequestered and returned nutrients to the soil in response to nitrogen (N) and phosphorus (P) availability. We tested the effect of nutrient availability on nutrient use efficiency, resorption efficiency, and resorption proficiency (% nutrient in senescent leaves) of Claytonia. Nutrient additions significantly decreased N but not P use efficiency of Claytonia, particularly as the growing season progressed. Nutrient additions also significantly reduced N resorption efficiency from 80 to 47% and decreased P resorption efficiency from 86 to 56%. N and P resorption proficiencies were also significantly lower in senesced leaves of fertilized plants: N concentrations were 2.33% when unfertilized and 4.13% when fertilized, while P concentrations were 0.43% when unfertilized versus 0.57% when fertilized. When unfertilized, Claytonia was more efficient at resorption compared with other spring herbs, but similar to other species when fertilized. However, Claytonia was much less proficient in resorbing nutrients than other reported plants, because senescent tissues maintained substantially higher concentrations of N and P, particularly when fertilized. In conclusion, Claytonia, an important spring ephemeral species, exhibits physiological responses that emphasize its role in the vernal dam by its temporary sequestration and substantial, rapid return of nutrients in deciduous forests. Adding nutrients to the site increases the total mass and the relative proportion of nutrients that Claytonia returns to the soil rather than sequestering between seasons, which ultimately increases nutrient recycling rates within the entire system.Key words: Claytonia virginica, nutrient response, resorption efficiency, nutrient cycling, spring ephemerals, vernal dam.
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Aerts R, Chapin F. The Mineral Nutrition of Wild Plants Revisited: A Re-evaluation of Processes and Patterns. ADV ECOL RES 1999. [DOI: 10.1016/s0065-2504(08)60016-1] [Citation(s) in RCA: 1207] [Impact Index Per Article: 48.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
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Aerts R, van Logtestijn R, van Staalduinen M, Toet S. Nitrogen supply effects on productivity and potential leaf litter decay of Carex species from peatlands differing in nutrient limitation. Oecologia 1995; 104:447-453. [PMID: 28307660 DOI: 10.1007/bf00341342] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/1995] [Accepted: 06/19/1995] [Indexed: 11/25/2022]
Abstract
We investigated the effect of increased N-supply on productivity and potential litter decay rates of Carex species, which are the dominant vascular plant species in peatlands in the Netherlands. We hypothesized that: (1) under conditions of N-limited plant growth, increased N-supply will lead to increased productivity but will not affect C:N ratios of plant litter and potential decay rates of that litter; and (2) under conditions of P-limited plant growth, increased N-supply will not affect productivity but it will lead to lower C:N ratios in plant litter and thereby to a higher potential decay rate of that litter. These hypotheses were tested by fertilization experiments (addition of 10 g N m-2 year-1) in peatlands in which plant growth was N-limited and P-limited, respectively. We investigated the effects of fertilization on net C-fixation by plant biomass, N uptake, leaf litter chemistry and potential leaf litter decay. In a P-limited peatland, dominated by Carex lasiocarpa, there was no significant increase of net C-fixation by plant biomass upon enhanced N-supply, although N-uptake had increased significantly compared with the unfertilized control. Due to the N-fertilization the C:N ratio in the plant biomass decreased significantly. Similarly, the C:N ratio of leaf litter produced at the end of the experiment showed a significant decrease upon enhanced N-supply. The potential decay rate of that litter, measured as CO2-evolution from the litter under aerobic conditions, was significantly increase upon enhanced N-supply. In a N-limited peatland, dominated by C. acutiformis, the net C-fixation by plant biomass increased with increasing N-supply, whereas the increase in N-uptake was not significant. The C:N ratio of both living plant material and of dead leaves did not change in response to N-fertilization. The potential decay rate of the leaf litter was not affected by N-supply. The results agree with our hypotheses. This implies that atmospheric N-deposition may affect the CO2-sink function of peatlands, but the effect is dependent on the nature of nutrient limitation. In peatlands where plant growth is N-limited, increased N-supply leads to an increase in the net accumulation of C. Under conditions of P-limited plant growth, however, the net C-accumulation will decrease, because productivity is not further increased, whereas the amount of C lost through decomposition of dead organic matter is increased. As plant growth in most terrestrial ecosystems is N-limited, increased N-supply will in most peatlands lead to an increase of net C-accumulation.
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Affiliation(s)
- R Aerts
- Department of Plant Ecology and Evolutionary Biology, Utrecht University, P.O. Box 800.84, NL-3508 TB, Utrecht, The Netherlands
| | - R van Logtestijn
- Department of Plant Ecology and Evolutionary Biology, Utrecht University, P.O. Box 800.84, NL-3508 TB, Utrecht, The Netherlands
| | - M van Staalduinen
- Department of Plant Ecology and Evolutionary Biology, Utrecht University, P.O. Box 800.84, NL-3508 TB, Utrecht, The Netherlands
| | - S Toet
- Department of Plant Ecology and Evolutionary Biology, Utrecht University, P.O. Box 800.84, NL-3508 TB, Utrecht, The Netherlands
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Interspecific and intraspecific differences in shoot and leaf lifespan of four Carex species which differ in maximum dry matter production. Oecologia 1995; 102:467-477. [DOI: 10.1007/bf00341359] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/1994] [Accepted: 01/14/1995] [Indexed: 11/26/2022]
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Separation of allelopathy and resource competition by the boreal dwarf shrub Empetrum hermaphroditum Hagerup. Oecologia 1994; 98:1-7. [PMID: 28312789 DOI: 10.1007/bf00326083] [Citation(s) in RCA: 133] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/1993] [Accepted: 01/29/1994] [Indexed: 10/26/2022]
Abstract
An experimental technique was used to separate and evaluate the magnitude of allelopathic interference relative to resource competition by the boreal dwarf shrub Empetrum hermaphroditum Hagerup (Empetraceae). To test for resource competition and allelopathy, respectively, Scots pine (Pinus sylvestris L.) seedlings were grown in both the greenhouse and in the field over a 3 year period, in four different treatments within E. hermaphroditum vegetation: (1) PVC tubes were used to reduce effects of interspecific below-ground competition; (2) activated carbon was spread on the soil to adsorb toxins leached from E. hermaphroditum litter and green leaves, thus reducing effects of allelopathic interference; (3) E. hermaphroditum vegetation was left untreated to evaluate inhibiting effects when both allelopathy and resource competition were present; (4) PVC tubes, placed in E. hermaphroditum vegetation spread with activated carbon were used to determine growth of seedlings when both allelopathy and resource competition were reduced. Scots pine seedlings grown in untreated vegetation (with both root competition and allelopathy present) had the lowest shoot length and dry weight; seedlings with both allelopathy and root competition reduced (activated carbon in tube) were the largest. Reducing either root competition alone (tube treatment) or allelopathy alone (carbon treatment) produced seedlings of intermediate size, but reduced competition had a greater effect than reduced allelopathy (although, in the greenhouse, significantly so only for root biomass). In the greenhouse experiment, biomass production of seedlings grown free of both interactions (carbon in tube) was greater than the simple sum of the growth response to the individual interactions (tube treatment and carbon treatment, respectively). Larger shoot:root ratios were also found when pine seedlings were grown without tubes (i.e. when resource competition was occurring). In the field, the removal of allelopathy (carbon treatments) increased shoot:root ratio when compared to the removal of resource competition. The study showed that two different interference mechanisms of E. hermaphroditum can be separated and quantified, and that below-ground competition and allelopathy by E. hermaphroditum are both important factors retarding growth of Scots pine.
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Tjoelker MG, Luxmoore RJ. Soil nitrogen and chronic ozone stress influence physiology, growth and nutrient status of Pinus taeda L. and Liriodendron tulipifera L. seedlings. THE NEW PHYTOLOGIST 1991; 119:69-81. [PMID: 33874340 DOI: 10.1111/j.1469-8137.1991.tb01009.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The effects of soil nitrogen availability and chronic ozone stress on carbon and nutrient economy were investigated in loblolly pine (Pinus. taeda L.) and yellow-poplar (Liriodendron tulipifera L.). One-year-old seedlings were planted individually in pots in forest soil of low (58 μg g-1 ), medium (96 μg g-1 ) or high (172 μg g-1 ) initial concentrations of soluble nitrogen. The seedlings were exposed to ozone in open-top field chambers at sub-ambient (charcoal-filtered air), ambient, and elevated (ambient + 60 nl 1-1 O3 ) (32, 56, 108 nl 1-1 O3 , 1 h seasonal mean, respectively) levels for 18 weeks. At final harvest loblolly pine dry matter increased by 50% at the highest soil K level relative to the low with the largest gains in new needle biomass. Elevated ozone reduced the biomass of current-year needles by 20% in plants grown at the highest N level. Higher soil N supply increased the concentration of nitrogen in needles, stimulated current-year needle photosynthesis and increased needle and whole-plant water-use efficiencies. Ozone treatment had no significant effect on photosynthesis or water-use efficiency in either species, although ozone exposure tended to reduce- stomatal conductance in loblolly pine. The low N treatment increased the proportion of dry matter allocated to fine roots in yellow-poplar, but whole-plant dry weight had not responded to N fertilization at the final harvest, suggesting other limitations on growth. Ozone exposure increased leaf abscission and doubled leaf turnover m yellow-poplar. Although yellow-poplar was highly sensitive to ozone-induced leaf abscission, final whole-plant dry weights were not affected. The indeterminate growth habit of yellow-poplar permitted compensatory leaf growth which may have ameliorated effects of chronic ozone stress on biomass gain. Ozone exposure also decreased shoot weight more than root weight, resulting in higher root:leaf ratios in loblolly pine and a similar trend m higher fine roor:leaf ratios in yellow-poplar. Greater proportional allocation of carbon to roots in response to nutrient deficiency may preclude an increased allocation to shoots often observed in response to air pollution stress. Interspecific differences in growth response to chronic ozone and nutrient stress may be influenced by differences in leaf growth habit.
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Affiliation(s)
- M G Tjoelker
- Environmental Sciences Division, Bldg. 1506 P.O. Box 2008, MS-6034, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6034 USA
| | - R J Luxmoore
- Environmental Sciences Division, Bldg. 1506 P.O. Box 2008, MS-6034, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6034 USA
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Aerts R. Nutrient use efficiency in evergreen and deciduous species from heathlands. Oecologia 1990; 84:391-397. [PMID: 28313031 DOI: 10.1007/bf00329765] [Citation(s) in RCA: 88] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/1990] [Accepted: 05/18/1990] [Indexed: 11/28/2022]
Abstract
The nutrient (N, P) use efficiency (NUE: g g-1 nutrient), measured for the entire plant, of field populations of the evergreen shrubs Erica tetralix (in a wet heathland) and Calluna vulgaris (in a dry heathland) and the deciduous grass Molinia caerulea (both in a wet and a dry heathland) was compared. Erica and Calluna are crowded out by Molinia when nutrient availability increases. NUE was measured as the product of the mean residence time of a unit of nutrient in the population (MRT: yr) and nutrient productivity (A: annual productivity per unit of nutrient in the population, g g-1 nutrient yr-1. It was hypothesized that 1) in low-nutrient habitats selection is on features leading to a high MRT, whereas in high-nutrient habitats selection is on features leading to a high A; and that 2) due to evolutionary trade-offs plants cannot combine genotypically determined features which maximize both components of NUE.Both total productivity and litter production of the Molinia populations exceeded that of both evergreens about three-fold. Nitrogen and phosphorus resorption from senescing shoots was much lower in the evergreens compared with Molinia. In a split-root experiment no nutrient resorption from senescing roots was observed. Nutrient concentrations in the litter were equal for all species, except for litter P-concentration of Molinia at the wet site. Both Erica and Calluna had a long mean residence time of both nitrogen and phosphorus and a low nitrogen and phosphorus productivity. The Molinia populations showed a shorter mean residence time of N and P and a higher N- and P-productivity. These patterns resulted in an equal nitrogen use efficiency and an almost equal phosphorus use efficiency for the species under study. However, when only aboveground NUE was considered the Molinia populations had a much higher NUE than the evergreens.The results are consistent with the hypotheses. Thus, the low potential growth rate of species from low-nutrient habitats is probably the consequence of their nutrient conserving strategy rather than a feature on which direct selection takes place in these habitats.
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Affiliation(s)
- Rien Aerts
- Department of Plant Ecology and Evolutionary Biology, University of Utrecht, Lange Nieuwstraat 106, NL-3512 PN, Utrecht, The Netherlands
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