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Heumann RE, Turner MG, Cleveland CC. Rates and controls of nitrogen fixation in postfire lodgepole pine forests. Ecology 2025; 106:e70016. [PMID: 39917901 DOI: 10.1002/ecy.70016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2024] [Accepted: 11/18/2024] [Indexed: 05/08/2025]
Abstract
Severe, stand-replacing wildfire substantially depletes nitrogen (N) stocks in subalpine conifer forests, potentially exacerbating N limitation of net primary productivity in many forested regions where fire frequency is increasing. In lodgepole pine (Pinus contorta var. latifolia) forests in the Greater Yellowstone Ecosystem (GYE), long-term data show surface soil and biomass N stocks are replenished during the first few decades following wildfire, but the source(s) of that N are unclear. We measured acetylene reduction rates in multiple cryptic niches (i.e., lichen, moss, pine litter, dead wood, and mineral soil) in 34-year-old lodgepole pine stands in the GYE to explore the rates, temporal patterns, and climate controls on cryptic N fixation. Acetylene reduction rates were highest in late May (0.376 nmol C2H4 g-1 h-1) when moisture availability was high compared with early August and mid-October when moisture was relatively low (0.112 and 0.002 nmol C2H4 g-1 h-1, respectively). We observed modest rates of nitrogenase activity in a few niches following a mid-summer rain event, suggesting that moisture is an important factor regulating field-based N fixation rates. In a laboratory experiment, moss responded more strongly to temperature and moisture variation than all other niches. Acetylene reduction rates in dead wood increased with temperature but not moisture content. No other niches showed clear responses to either moisture or temperature manipulation. Together, the field and laboratory results suggest that frequent asynchrony between favorable temperature and moisture conditions may limit N fixation rates in the field. Overall, total annual cryptic N fixation inputs (mean: 0.26; range: 0.07-2.9 kg N ha-1 year-1) represented <10% of the postfire biomass and surface soil N accumulation in the same stands (39.4 kg N ha-1 year-1), pointing to a still unknown source of ecosystem N following fire.
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Affiliation(s)
- Robert E Heumann
- Department of Ecosystem and Conservation Sciences, W.A. Franke College of Forestry and Conservation, University of Montana, Missoula, Montana, USA
| | - Monica G Turner
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Cory C Cleveland
- Department of Ecosystem and Conservation Sciences, W.A. Franke College of Forestry and Conservation, University of Montana, Missoula, Montana, USA
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Guerrieri R, Correia M, Martín‐Forés I, Alfaro‐Sánchez R, Pino J, Hampe A, Valladares F, Espelta JM. Land‐use legacies influence tree water‐use efficiency and nitrogen availability in recently established European forests. Funct Ecol 2021. [DOI: 10.1111/1365-2435.13787] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Rossella Guerrieri
- CREAF Centre de Recerca Ecològica i Aplicacions ForestalsCatalonia Spain
- DISTAL University of Bologna Bologna Italy
| | - Marta Correia
- Centre for Functional Ecology Department of Life Sciences Calçada Martim de FreitasUniversity of Coimbra Coimbra Portugal
| | - Irene Martín‐Forés
- Department of Biogeography and Global Change National Museum of Natural SciencesSpanish Council for Scientific ResearchCSIC Madrid Spain
- School of Biological Sciences The University of Adelaide Adelaide SA Australia
| | - Raquel Alfaro‐Sánchez
- CREAF Centre de Recerca Ecològica i Aplicacions ForestalsCatalonia Spain
- Department of Biology Wilfrid Laurier University Waterloo ON Canada
| | - Joan Pino
- CREAF Centre de Recerca Ecològica i Aplicacions ForestalsCatalonia Spain
- Universitat Autònoma de Barcelona Catalonia Spain
| | - Arndt Hampe
- INRAEUniversity of BordeauxBIOGECO Cestas France
| | - Fernando Valladares
- Department of Biogeography and Global Change National Museum of Natural SciencesSpanish Council for Scientific ResearchCSIC Madrid Spain
| | - Josep Maria Espelta
- CREAF Centre de Recerca Ecològica i Aplicacions ForestalsCatalonia Spain
- Universitat Autònoma de Barcelona Catalonia Spain
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3
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Ecosystem Recovery from Disturbance is Constrained by N Cycle Openness, Vegetation-Soil N Distribution, Form of N Losses, and the Balance Between Vegetation and Soil-Microbial Processes. Ecosystems 2020. [DOI: 10.1007/s10021-020-00542-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Figueiredo V, Enrich-Prast A, Rütting T. Evolution of nitrogen cycling in regrowing Amazonian rainforest. Sci Rep 2019; 9:8538. [PMID: 31189968 PMCID: PMC6561906 DOI: 10.1038/s41598-019-43963-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 04/12/2019] [Indexed: 11/16/2022] Open
Abstract
Extensive regions of tropical forests are subjected to high rates of deforestation and forest regrowth and both are strongly affect soil nutrient cycling. Nitrogen (N) dynamics changes during forest regrowth and the recovery of forests and functioning similar to pristine conditions depends on sufficient N availability. We show that, in a chronosequence of Amazonian forests, gross nitrification and, as a result, nitrate-to-ammonium (NO3-: NH4+) ratio were lower in all stages of regrowing forests (10 to 40 years) compared to pristine forest. This indicates the evolution of a more conservative and closed N cycle with reduced risk for N leaking out of the ecosystem in regrowing forests. Furthermore, our results indicate that mineralization and nitrification are decoupled in young regrowing forests (10 years), such as that high gross mineralization is accompanied by low gross nitrification, demonstrating a closed N cycle that at the same time maintains N supply for forest regrowth. We conclude that the status of gross nitrification in disturbed soil is a key process to understand the mechanisms of and time needed for tropical forest recovery.
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Affiliation(s)
- Viviane Figueiredo
- Department of Botany, University Federal of Rio de Janeiro, 21941-971 Avenida Carlos Chagas Filho, Rio de Janeiro, Brazil
- Postgraduate Program in Geochemistry, University Federal Fluminense, 24020-007 Outeiro de São João Batista, Niterói, Brazil
- Postgraduate Program in Biotechnology, University Federal of Rio de Janeiro, 21941-971 Avenida Carlos Chagas Filho, Rio de Janeiro, Brazil
| | - Alex Enrich-Prast
- Department of Botany, University Federal of Rio de Janeiro, 21941-971 Avenida Carlos Chagas Filho, Rio de Janeiro, Brazil.
- Postgraduate Program in Geochemistry, University Federal Fluminense, 24020-007 Outeiro de São João Batista, Niterói, Brazil.
- Postgraduate Program in Biotechnology, University Federal of Rio de Janeiro, 21941-971 Avenida Carlos Chagas Filho, Rio de Janeiro, Brazil.
- Department of Environmental Change, Linköping University, 58183, Linköping, Sweden.
| | - Tobias Rütting
- Department of Earth Sciences, University of Gothenburg, 405 30, Gothenburg, Sweden
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5
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Isotopic evidence for oligotrophication of terrestrial ecosystems. Nat Ecol Evol 2018; 2:1735-1744. [DOI: 10.1038/s41559-018-0694-0] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 09/12/2018] [Indexed: 11/09/2022]
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6
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English PA, Green DJ, Nocera JJ. Stable Isotopes from Museum Specimens May Provide Evidence of Long-Term Change in the Trophic Ecology of a Migratory Aerial Insectivore. Front Ecol Evol 2018. [DOI: 10.3389/fevo.2018.00014] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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7
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Kim SL, Shuman BN, Minckley TA, Marsicek JP. Biogeochemical Change During Climate-Driven Afforestation: A Paleoecological Perspective from the Rocky Mountains. Ecosystems 2016. [DOI: 10.1007/s10021-015-9955-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Serbin SP, Singh A, McNeil BE, Kingdon CC, Townsend PA. Spectroscopic determination of leaf morphological and biochemical traits for northern temperate and boreal tree species. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2016; 24:1651-1669. [PMID: 29210229 DOI: 10.1890/13-2110.1] [Citation(s) in RCA: 124] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The morphological and biochemical properties of plant canopies are strong predictors of photosynthetic capacity and nutrient cycling. Remote sensing research at the leaf and canopy scales has demonstrated the ability to characterize the biochemical status of vegetation canopies using reflectance spectroscopy, including at the leaf level and canopy level from air- and spaceborne imaging spectrometers. We developed a set of accurate and precise spectroscopic calibrations for the determination of leaf chemistry (contents of nitrogen, carbon, and fiber constituents), morphology (leaf mass per area, Marea), and isotopic composition (δ15N) of temperate and boreal tree species using spectra of dried and ground leaf material. The data set consisted of leaves from both broadleaf and needle-leaf conifer species and displayed a wide range in values, determined with standard analytical approaches: 0.7–4.4% for nitrogen (Nmass), 42–54% for carbon (Cmass), 17–58% for fiber (acid-digestible fiber, ADF), 7–44% for lignin (acid-digestible lignin, ADL), 3–31% for cellulose, 17–265 g/m2 for Marea, and −9.4‰ to 0.8‰ for δ15N. The calibrations were developed using a partial least-squares regression (PLSR) modeling approach combined with a novel uncertainty analysis. Our PLSR models yielded model calibration (independent validation shown in parentheses) R2 and the root mean square error (RMSE) values, respectively, of 0.98 (0.97) and 0.10% (0.13%) for Nmass, R2 = 0.77 (0.73) and RMSE = 0.88% (0.95%) for Cmass, R2 = 0.89 (0.84) and RMSE = 2.8% (3.4%) for ADF, R2 = 0.77 (0.69) and RMSE = 2.4% (3.9%) for ADL, R2 = 0.77 (0.72) and RMSE = 1.4% (1.9%) for leaf cellulose, R2 = 0.62 (0.60) and RMSE = 0.91‰ (1.5‰) for δ15N, and R2 = 0.88 (0.87) with RMSE = 17.2 g/m2 (22.8 g/m2) for Marea. This study demonstrates the potential for rapid and accurate estimation of key foliar traits of forest canopies that are important for ecological research and modeling activities, with a single calibration equation valid over a wide range of northern temperate and boreal species and leaf physiognomies. The results provide the basis to characterize important variability between and within species, and across ecological gradients using a rapid, cost-effective, easily replicated method.
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Perakis SS, Tepley AJ, Compton JE. Disturbance and Topography Shape Nitrogen Availability and δ15N over Long-Term Forest Succession. Ecosystems 2015. [DOI: 10.1007/s10021-015-9847-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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10
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Dunnette PV, Higuera PE, McLauchlan KK, Derr KM, Briles CE, Keefe MH. Biogeochemical impacts of wildfires over four millennia in a Rocky Mountain subalpine watershed. THE NEW PHYTOLOGIST 2014; 203:900-912. [PMID: 24803372 DOI: 10.1111/nph.12828] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Accepted: 03/31/2014] [Indexed: 06/03/2023]
Abstract
Wildfires can significantly alter forest carbon (C) storage and nitrogen (N) availability, but the long-term biogeochemical legacy of wildfires is poorly understood. We obtained a lake-sediment record of fire and biogeochemistry from a subalpine forest in Colorado, USA, to examine the nature, magnitude, and duration of decadal-scale, fire-induced ecosystem change over the past c. 4250 yr. The high-resolution record contained 34 fires, including 13 high-severity events within the watershed. High-severity fires were followed by increased sedimentary N stable isotope ratios (δ15N) and bulk density, and decreased C and N concentrations--reflecting forest floor destruction, terrestrial C and N losses, and erosion. Sustained low sediment C : N c. 20-50 yr post-fire indicates reduced terrestrial organic matter subsidies to the lake. Low sedimentary δ15N c. 50-70 yr post-fire, coincident with C and N recovery, suggests diminishing terrestrial N availability during stand development. The magnitude of post-fire changes generally scaled directly with inferred fire severity. Our results support modern studies of forest successional C and N accumulation and indicate pronounced, long-lasting biogeochemical impacts of wildfires in subalpine forests. However, even repeated high-severity fires over millennia probably did not deplete C or N stocks, because centuries between high-severity fires allowed for sufficient biomass recovery.
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Affiliation(s)
- Paul V Dunnette
- College of Natural Resources, University of Idaho, PO Box 441133, Moscow, ID, 83844-1133, USA
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11
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Broadbent EN, Almeyda Zambrano AM, Asner GP, Soriano M, Field CB, de Souza HR, Peña-Claros M, Adams RI, Dirzo R, Giles L. Integrating stand and soil properties to understand foliar nutrient dynamics during forest succession following slash-and-burn agriculture in the Bolivian Amazon. PLoS One 2014; 9:e86042. [PMID: 24516525 PMCID: PMC3917844 DOI: 10.1371/journal.pone.0086042] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Accepted: 12/04/2013] [Indexed: 11/19/2022] Open
Abstract
Secondary forests cover large areas of the tropics and play an important role in the global carbon cycle. During secondary forest succession, simultaneous changes occur among stand structural attributes, soil properties, and species composition. Most studies classify tree species into categories based on their regeneration requirements. We use a high-resolution secondary forest chronosequence to assign trees to a continuous gradient in species successional status assigned according to their distribution across the chronosequence. Species successional status, not stand age or differences in stand structure or soil properties, was found to be the best predictor of leaf trait variation. Foliar δ(13)C had a significant positive relationship with species successional status, indicating changes in foliar physiology related to growth and competitive strategy, but was not correlated with stand age, whereas soil δ(13)C dynamics were largely constrained by plant species composition. Foliar δ(15)N had a significant negative correlation with both stand age and species successional status, - most likely resulting from a large initial biomass-burning enrichment in soil (15)N and (13)C and not closure of the nitrogen cycle. Foliar %C was neither correlated with stand age nor species successional status but was found to display significant phylogenetic signal. Results from this study are relevant to understanding the dynamics of tree species growth and competition during forest succession and highlight possibilities of, and potentially confounding signals affecting, the utility of leaf traits to understand community and species dynamics during secondary forest succession.
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Affiliation(s)
- Eben N. Broadbent
- Department of Global Ecology, Carnegie Institution for Science, Stanford, California, United States of America
- Department of Biology, Stanford University, Stanford, California, United States of America
- Sustainability Science Program, Kennedy School of Government, Harvard University, Cambridge, Massachusetts, United States of America
| | - Angélica M. Almeyda Zambrano
- Department of Global Ecology, Carnegie Institution for Science, Stanford, California, United States of America
- Sustainability Science Program, Kennedy School of Government, Harvard University, Cambridge, Massachusetts, United States of America
- Department of Anthropology, Stanford University, Stanford, California, United States of America
| | - Gregory P. Asner
- Department of Global Ecology, Carnegie Institution for Science, Stanford, California, United States of America
| | - Marlene Soriano
- Instituto Boliviano de Investigación Forestal, Santa Cruz de la Sierra, Bolivia
| | - Christopher B. Field
- Department of Global Ecology, Carnegie Institution for Science, Stanford, California, United States of America
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Harrison Ramos de Souza
- Centro de Investigación y Preservación de la Amazonia, Universidad Amazónica de Pando, Cobija, Bolivia
| | - Marielos Peña-Claros
- Instituto Boliviano de Investigación Forestal, Santa Cruz de la Sierra, Bolivia
- Forest Ecology and Forest Management Group, Wageningen University, Wageningen, the Netherlands
| | - Rachel I. Adams
- Plant and Microbial Biology, University of California, Berkeley, California, United States of America
| | - Rodolfo Dirzo
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Larry Giles
- Department of Global Ecology, Carnegie Institution for Science, Stanford, California, United States of America
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12
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Wang A, Fang YT, Chen DX, Koba K, Makabe A, Li YD, Luo TS, Yoh M. Variations in nitrogen-15 natural abundance of plant and soil systems in four remote tropical rainforests, southern China. Oecologia 2013; 174:567-80. [DOI: 10.1007/s00442-013-2778-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Accepted: 09/05/2013] [Indexed: 11/29/2022]
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13
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Bai E, Boutton TW, Liu F, Wu XB, Archer SR. 15N isoscapes in a subtropical savanna parkland: spatial-temporal perspectives. Ecosphere 2013. [DOI: 10.1890/es12-00187.1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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14
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Hobbie EA, Högberg P. Nitrogen isotopes link mycorrhizal fungi and plants to nitrogen dynamics. NEW PHYTOLOGIST 2012; 196:367-382. [PMID: 22963677 DOI: 10.1111/j.1469-8137.2012.04300.x] [Citation(s) in RCA: 181] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Accepted: 07/13/2012] [Indexed: 05/23/2023]
Affiliation(s)
- Erik A. Hobbie
- Earth Systems Research Center University of New Hampshire Durham NH 03824 USA
| | - Peter Högberg
- Department of Forest Ecology and Management Swedish University of Agricultural Sciences (SLU) SE‐901 83 Umeå Sweden
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Gundale MJ, Hyodo F, Nilsson MC, Wardle DA. Nitrogen niches revealed through species and functional group removal in a boreal shrub community. Ecology 2012; 93:1695-706. [DOI: 10.1890/11-1877.1] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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16
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Nitrogen Isotope Patterns in Alaskan Black Spruce Reflect Organic Nitrogen Sources and the Activity of Ectomycorrhizal Fungi. Ecosystems 2012. [DOI: 10.1007/s10021-012-9548-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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17
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Gelfand I, Grünzweig JM, Yakir D. Slowing of nitrogen cycling and increasing nitrogen use efficiency following afforestation of semi-arid shrubland. Oecologia 2011; 168:563-75. [DOI: 10.1007/s00442-011-2111-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2010] [Accepted: 08/15/2011] [Indexed: 11/30/2022]
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18
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Coelho GC, Rigo MDS, Libardoni JB, Oliveira RD, Benvenuti-Ferreira G. Understory structure in two successional stages of a Semi-deciduous Seasonal Forest remnant of Southern Brazil. BIOTA NEOTROPICA 2011. [DOI: 10.1590/s1676-06032011000300004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The knowledge of structure and composition of forest strata contributes to understanding the conservation status and dynamics of plant communities. The study of forest understory is important to the knowledge of the succession process. The Seasonal Subtropical Forest remnant named Mato do Silva (27º 55'26" S and 53º 53'15" W) was studied aiming to describe the structure of understory in the late successional forest (LF) and in the young secondary forest (SF), an 11 years old post-agricultural site with canopy dominance of Ateleia glazioveana Baill. The phytosociological survey was carried out through the point quarter method and included individuals of tree and shrub species from 0.5 to 3.0 m of height. The sampling consisted of 384 individuals in LF (67 species) and 284 individuals in SF (20 species). A total of 79 species were observed, and only eight species occurred in both areas. The specific diversity (H') was 3.45 and 2.42 nats in the understory of LF and SF, respectively. The Pielou's evenness index (J) was 0.85 to LF and 0.80 to SF, respectively. Cupania vernalis Camb. and Psychotria leiocarpa Müll. Arg. were the prominent species in the LF while A. glazioveana and Solanum mauritianum Scop. were outstanding in the SF understory. Shade-tolerant and late secondary tree species occurred in large proportion in the LF forest, while pioneers and early secondary tree species predominated in the SF. In addition, certain dominant species in the understory of the SF were absent in the LF understory, such as A. glazioveana, Solanum compressum L. B. Sm. & Downs, Helietta apiculata Bentham and Gledtisia amorphoides (Griseb.) Taubert, which indicates that such species are associated to early stages of forest succession. G. amorphoides is considered an endangered species, and the early successional stages could be necessary for conservation of this species. A decrease in the pH and mineral nutrient levels in the soil was linked to the successional process, indicating the transference of nutrients to the aboveground biomass.
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Perakis SS, Sinkhorn ER, Compton JE. δ15N constraints on long-term nitrogen balances in temperate forests. Oecologia 2011; 167:793-807. [PMID: 21614618 DOI: 10.1007/s00442-011-2016-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Accepted: 04/28/2011] [Indexed: 10/18/2022]
Abstract
Biogeochemical theory emphasizes nitrogen (N) limitation and the many factors that can restrict N accumulation in temperate forests, yet lacks a working model of conditions that can promote naturally high N accumulation. We used a dynamic simulation model of ecosystem N and δ(15)N to evaluate which combination of N input and loss pathways could produce a range of high ecosystem N contents characteristic of forests in the Oregon Coast Range. Total ecosystem N at nine study sites ranged from 8,788 to 22,667 kg ha(-1) and carbon (C) ranged from 188 to 460 Mg ha(-1), with highest values near the coast. Ecosystem δ(15)N displayed a curvilinear relationship with ecosystem N content, and largely reflected mineral soil, which accounted for 96-98% of total ecosystem N. Model simulations of ecosystem N balances parameterized with field rates of N leaching required long-term average N inputs that exceed atmospheric deposition and asymbiotic and epiphytic N(2)-fixation, and that were consistent with cycles of post-fire N(2)-fixation by early-successional red alder. Soil water δ(15)NO(3)(-) patterns suggested a shift in relative N losses from denitrification to nitrate leaching as N accumulated, and simulations identified nitrate leaching as the primary N loss pathway that constrains maximum N accumulation. Whereas current theory emphasizes constraints on biological N(2)-fixation and disturbance-mediated N losses as factors that limit N accumulation in temperate forests, our results suggest that wildfire can foster substantial long-term N accumulation in ecosystems that are colonized by symbiotic N(2)-fixing vegetation.
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Affiliation(s)
- Steven S Perakis
- Forest and Rangeland Ecosystem Science Center, US Geological Survey, Corvallis, OR 97331, USA.
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20
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Yang Y, Luo Y. Carbon : nitrogen stoichiometry in forest ecosystems during stand development. GLOBAL ECOLOGY AND BIOGEOGRAPHY 2011; 20:354-361. [PMID: 0 DOI: 10.1111/j.1466-8238.2010.00602.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
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21
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Garten CT, Iversen CM, Norby RJ. Litterfall15N abundance indicates declining soil nitrogen availability in a free-air CO2enrichment experiment. Ecology 2011; 92:133-9. [DOI: 10.1890/10-0293.1] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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22
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Donohue I, Leira M, Hobbs W, León-Vintró L, O'Reilly J, Irvine K. Rapid ecosystem recovery from diffuse pollution after the Great Irish Famine. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2010; 20:1733-1743. [PMID: 20945771 DOI: 10.1890/09-1966.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Remarkably little is known about the effectiveness or rates of recovery of aquatic ecosystems from reductions in human-associated pressures at landscape scales. The retention of anthropogenic contaminants within ecosystems can retard rates of recovery considerably, while the trajectories of recovery processes vary with the extent of disturbance and the resilience of biotic assemblages. The Great Irish Famine of 1845-1850 comprised one of the most significant human disasters of the 19th century, causing the death of approximately one million people and the emigration of a further two million from the country between 1845 and 1855. We found, through analysis of detailed historical census data combined with paleolimnological investigation of sedimentary nutrient concentrations, stable isotope ratios, and diatom assemblages, that the trophic level of Lough Carra, a largely shallow calcareous lake in the west of Ireland with no urban areas or point sources of any significance in its catchment, reduced considerably during and immediately after the Great Famine, shifting to new equilibria within just 2-10 years. Our results demonstrate that the reduction of human pressures from diffuse sources at landscape scales can result in the rapid and monotonic recovery of aquatic ecosystems. Moreover, the recovery of ecosystems from diffuse pollution need not necessarily take longer than recovery from pollution from point sources.
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Affiliation(s)
- Ian Donohue
- School of Natural Sciences, Department of Zoology, Trinity College, Dublin 2, Ireland.
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Hyodo F, Wardle DA. Effect of ecosystem retrogression on stable nitrogen and carbon isotopes of plants, soils and consumer organisms in boreal forest islands. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2009; 23:1892-1898. [PMID: 19462406 DOI: 10.1002/rcm.4095] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
In the prolonged absence of catastrophic disturbance, ecosystem retrogression occurs, and this involves increased nutrient limitation, and reduced aboveground and belowground ecosystem processes rates. Little is known about how the nitrogen and carbon stable isotope ratios (delta(15)N and delta(13)C) of plants, soils and consumer organisms respond to retrogression in boreal forests. We investigated a 5000 year chronosequence of forested islands in the boreal zone of northern Sweden, for which the time since lightning-induced wildfire increases with decreasing island size, leading to ecosystem retrogression. For this system, tissue delta(15)N of three abundant plant species (Betula pubescens, Vaccinium myrtillus and Pleurozium schreberi) and humus all increased as retrogression proceeded. This is probably due to enhanced ecosystem inputs of N by biological fixation, and greater dependency of the plants on organic N during retrogression. The delta(13)C of B. pubescens and plant-derived humus also increased during retrogression, probably through nutrient limitation increasing plant physiological stress. Unlike the plants, delta(15)N of invertebrates (lycosid spiders and ants) did not increase during retrogression, probably because of their partial dependence on aquatic-derived prey that had a variable delta(15)N signature. The delta(13)C of the invertebrates increased as retrogression proceeded and converged towards that of an aquatic prey source (chironomid flies), suggesting increased dependence on aquatic-derived prey during retrogression. These results show that measurement of delta(15)N and delta(13)C of plants, soils, and consumers across the same environmental gradient can provide insights into environmental factors that drive both the aboveground and belowground subsystems, as well as the linkages between them.
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Affiliation(s)
- Fujio Hyodo
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, S901 83 Umeå, Sweden.
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Increasing abundance of soil fungi is a driver for 15N enrichment in soil profiles along a chronosequence undergoing isostatic rebound in northern Sweden. Oecologia 2009; 160:87-96. [DOI: 10.1007/s00442-008-1270-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2007] [Accepted: 12/15/2008] [Indexed: 10/21/2022]
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