1
|
Yang J, Wu F, Wei X, Zhang X, Wu Q, Yue K, Ni X. Global Positive Effects of Litter Inputs on Soil Nitrogen Pools and Fluxes. Ecosystems 2022. [DOI: 10.1007/s10021-022-00800-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
2
|
Xiao L, Zhang W, Hu P, Xiao D, Yang R, Ye Y, Wang K. The formation of large macroaggregates induces soil organic carbon sequestration in short-term cropland restoration in a typical karst area. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 801:149588. [PMID: 34425448 DOI: 10.1016/j.scitotenv.2021.149588] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 07/15/2021] [Accepted: 08/07/2021] [Indexed: 06/13/2023]
Abstract
Cropland restoration induces litter and root inputs and promotes the development of biological soil crusts (BSCs), which may promote aggregate formation and soil organic carbon (SOC) sequestration. However, litter, roots and BSCs have not been simultaneously considered when assessing soil aggregate and aggregate-associated SOC fraction responses to cropland restoration in subtropical areas. Here, we measured particulate organic carbon (POC) and mineral-associated organic carbon (MOC) in bulk soils and soil aggregates after 15 years of cropland restoration. Soil samples of cropland (CL) and four cropland restoration types (plantation forest [PF], forage grassland [FG], mixed plantation of forest and forage grassland [FF], and abandoned natural grassland [NG]) from depths of 0-30 cm were collected. Cropland restoration significantly increased SOC and POC in bulk soil at the 0-5 cm depth. However, only in FG did SOC significantly increase at depths of 5-15 cm, and POC significantly increased at depths of 5-30 cm. The large macroaggregate (5-10 mm and 2-5 mm) proportions increased significantly at the 0-15 cm depth after cropland restoration, and FG, FF and NG also increased the 5-10 mm aggregate proportions at the 15-30 cm depth. The SOC sequestration in bulk soil with cropland restoration was attributed to increases in the aggregate-associated organic carbon (AAOC) pool in large macroaggregates, which was mainly attributed to the increased aggregate amount rather than the increased AAOC concentration in large macroaggregates. Our results also indicated that an increase in aggregate-associated particulate organic carbon (AAPOC) led to an increase in AAOC. Variation partitioning indicated that the formation of large macroaggregates was controlled by the litter-moss-root interactive effect in this karst area. FG could be a better short-term cropland restoration strategy, increasing large macroaggregates in deeper soil layers better than the other vegetation types and promoting soil carbon sequestration in deeper soil layers.
Collapse
Affiliation(s)
- Lumei Xiao
- Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China; Huanjiang Observation and Research Station for Karst Ecosystems, Huanjiang 547100, China; University of Chinese Academy of Science, Beijing 100049, China
| | - Wei Zhang
- Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China; Huanjiang Observation and Research Station for Karst Ecosystems, Huanjiang 547100, China.
| | - Peilei Hu
- Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China; Huanjiang Observation and Research Station for Karst Ecosystems, Huanjiang 547100, China
| | - Dan Xiao
- Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China; Huanjiang Observation and Research Station for Karst Ecosystems, Huanjiang 547100, China
| | - Rong Yang
- Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China; Huanjiang Observation and Research Station for Karst Ecosystems, Huanjiang 547100, China; University of Chinese Academy of Science, Beijing 100049, China
| | - Yingying Ye
- Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China; Huanjiang Observation and Research Station for Karst Ecosystems, Huanjiang 547100, China
| | - Kelin Wang
- Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China; Huanjiang Observation and Research Station for Karst Ecosystems, Huanjiang 547100, China.
| |
Collapse
|
3
|
Ecophysiological Study of Paraburkholderia sp. Strain 1N under Soil Solution Conditions: Dynamic Substrate Preferences and Characterization of Carbon Use Efficiency. Appl Environ Microbiol 2020; 86:AEM.01851-20. [PMID: 33008817 PMCID: PMC7688210 DOI: 10.1128/aem.01851-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 09/24/2020] [Indexed: 11/20/2022] Open
Abstract
We used time-resolved metabolic footprinting, an important technical approach used to monitor changes in extracellular compound concentrations during microbial growth, to study the order of substrate utilization (i.e., substrate preferences) and kinetics of a fast-growing soil isolate, Paraburkholderia sp. strain 1N. The growth of Paraburkholderia sp. 1N was monitored under aerobic conditions in a soil-extracted solubilized organic matter medium, representing a realistic diversity of available substrates and gradient of initial concentrations. We combined multiple analytical approaches to track over 150 compounds in the medium and complemented this with bulk carbon and nitrogen measurements, allowing estimates of carbon use efficiency throughout the growth curve. Targeted methods allowed the quantification of common low-molecular-weight substrates: glucose, 20 amino acids, and 9 organic acids. All targeted compounds were depleted from the medium, and depletion followed a sigmoidal curve where sufficient data were available. Substrates were utilized in at least three distinct temporal clusters as Paraburkholderia sp. 1N produced biomass at a cumulative carbon use efficiency of 0.43. The two substrates with highest initial concentrations, glucose and valine, exhibited longer usage windows, at higher biomass-normalized rates, and later in the growth curve. Contrary to hypotheses based on previous studies, we found no clear relationship between substrate nominal oxidation state of carbon (NOSC) or maximal growth rate and the order of substrate depletion. Under soil solution conditions, the growth of Paraburkholderia sp. 1N induced multiauxic substrate depletion patterns that could not be explained by the traditional paradigm of catabolite repression.IMPORTANCE Exometabolomic footprinting methods have the capability to provide time-resolved observations of the uptake and release of hundreds of compounds during microbial growth. Of particular interest is microbial phenotyping under environmentally relevant soil conditions, consisting of relatively low concentrations and modeling pulse input events. Here, we show that growth of a bacterial soil isolate, Paraburkholderia sp. 1N, on a dilute soil extract resulted in a multiauxic metabolic response, characterized by discrete temporal clusters of substrate depletion and metabolite production. Our data did not support the hypothesis that compounds with lower energy content are used preferentially, as each cluster contained compounds with a range of nominal oxidation states of carbon. These new findings with Paraburkholderia sp. 1N, which belongs to a metabolically diverse genus, provide insights on ecological strategies employed by aerobic heterotrophs competing for low-molecular-weight substrates in soil solution.
Collapse
|
4
|
Wilhelm RC, Cyle KT, Martinez CE, Karasz DC, Newman JD, Buckley DH. Paraburkholderia solitsugae sp. nov. and Paraburkholderia elongata sp. nov., phenolic acid-degrading bacteria isolated from forest soil and emended description of Paraburkholderia madseniana. Int J Syst Evol Microbiol 2020; 70:5093-5105. [PMID: 32809929 DOI: 10.1099/ijsem.0.004387] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Two bacterial strains, 1NT and 5NT, were isolated from hemlock forest soil using a soluble organic matter enrichment. Cells of 1NT (0.65×1.85 µm) and 5NT (0.6×1.85 µm) are Gram-stain-negative, aerobic, motile, non-sporulating and exist as single rods, diplobacilli or in chains of varying length. During growth in dilute media (≤0.1× tryptic soy broth; TSB), cells are primarily motile with flagella. At higher concentrations (≥0.3× TSB), cells of both strains increasingly form non-motile chains, and cells of 5NT elongate (0.57×~7 µm) and form especially long filaments. Optimum growth of 1NT and 5NT occurred at 25-30 °C, pH 6.5-7.0 and <0.5% salinity. Results of comparative chemotaxonomic, genomic and phylogenetic analyses revealed that 1NT and 5NT were distinct from one another and their closest related type strains: Paraburkholderia madseniana RP11T, Paraburkholderia aspalathi LMG 27731T and Paraburkholderia caffeinilytica CF1T. The genomes of 1NT and 5NT had an average nucleotide identity (91.6 and 91.3%) and in silico DNA-DNA hybridization values (45.8%±2.6 and 45.5%±2.5) and differed in functional gene content from their closest related type strains. The composition of fatty acids and patterns of substrate use, including the catabolism of phenolic acids, also differentiated strains 1NT and 5NT from each other and their closest relatives. The only ubiquinone present in strains 1NT and 5NT was Q-8. The major cellular fatty acids were C16 : 0, 3OH-C16 : 0, C17 : 0 cyclo, C19 : 0 cyclo ω8c and summed features 2 (3OH-C14 : 0 / C16 : 1 iso I), 3 (C16 : 1 ω6c/ω7c) and 8 (C18 : 1 ω7c/ω6c). A third bacterium, strain RL16-012-BIC-B, was isolated from soil associated with shallow roots and was determined to be a strain of P. madseniana (ANI, 98.8%; 16S rRNA gene similarity, 100%). Characterizations of strain RL16-012-BIC-B (DSM 110723=LMG 31706) led to proposed emendments to the species description of P. madseniana. Our polyphasic approach demonstrated that strains 1NT and 5NT represent novel species from the genus Paraburkholderia for which the names Paraburkholderia solitsugae sp. nov. (type strain 1NT=DSM 110721T=LMG 31704T) and Paraburkholderia elongata sp. nov. (type strain 5NT=DSM 110722T=LMG 31705T) are proposed.
Collapse
Affiliation(s)
- Roland C Wilhelm
- School of Integrative Plant Sciences, Bradfield Hall, Cornell University, Ithaca, NY, 14853, USA
| | - K Taylor Cyle
- School of Integrative Plant Sciences, Bradfield Hall, Cornell University, Ithaca, NY, 14853, USA
| | - Carmen Enid Martinez
- School of Integrative Plant Sciences, Bradfield Hall, Cornell University, Ithaca, NY, 14853, USA
| | - David C Karasz
- School of Integrative Plant Sciences, Bradfield Hall, Cornell University, Ithaca, NY, 14853, USA
| | | | - Daniel H Buckley
- School of Integrative Plant Sciences, Bradfield Hall, Cornell University, Ithaca, NY, 14853, USA
| |
Collapse
|
5
|
Buchkowski RW, Shaw AN, Sihi D, Smith GR, Keiser AD. Constraining Carbon and Nutrient Flows in Soil With Ecological Stoichiometry. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00382] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
6
|
Nagib AM, Elsayed Matter Y, Ashry Gheith O, Fathi Refaie A, Othman NF, Al-Otaibi T. Diabetic Nephropathy Following Posttransplant Diabetes Mellitus. EXP CLIN TRANSPLANT 2019; 17:138-146. [DOI: 10.6002/ect.2018.0157] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
7
|
Fuss CB, Lovett GM, Goodale CL, Ollinger SV, Lang AK, Ouimette AP. Retention of Nitrate-N in Mineral Soil Organic Matter in Different Forest Age Classes. Ecosystems 2019. [DOI: 10.1007/s10021-018-0328-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
8
|
Tanaka TST, Irbis C, Hama Y, Wang P, Li K, Inamura T. A small proportion of litter-derived nitrogen is assimilated by plant biomass or immobilized in sediments regardless of harvest management as detected by 15N-labeled Phragmites litter in a constructed wetland. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2018; 217:888-896. [PMID: 29665568 DOI: 10.1016/j.jenvman.2018.03.045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 03/06/2018] [Accepted: 03/11/2018] [Indexed: 06/08/2023]
Abstract
Emergent aquatic macrophytes play an important role in the removal of nutrients in constructed wetlands (CWs). However, plant biomass supplies litter after the onset of senescence. Although litter-derived nitrogen (N) has been considered a nutrient source for the internal loading that may reduce CW performance, little is known about the quantitative N dynamics associated with litter decomposition. Thus, a controversial question remains about whether plant harvest is needed to manage CWs. In this study, we evaluated the decomposition and the fate of N derived from 15N-labeled Phragmites litter in a CW for 1 year. To simulate respective natural conditions, two treatments, including (1) a single winter harvest and (2) no harvest where the latter supplies a greater stem litterfall, were compared. Although the dry weight of the added stem litter was approximately 4.7 times larger in the no harvest plot than in the harvest plot, the total N content of the initial 15N-labeled litter was only 1.2 times higher in the no harvest plot than in the harvest plots because of the low N concentration in the stem litter. The litter functioned as a minor N sink within the first 6 months of decomposition, and it then shifted to functioning as a minor N source after 1 year of decomposition. The recovery of litter-derived N in the sediment and plant biomass was low (less than 10% of the initial litter N), and much of the remaining N might have been released into ambient water or lost through denitrification. Furthermore, our results suggested a potentially low contribution of litter-derived N to internal N loading for at least 1 year regardless of the harvest management treatment.
Collapse
Affiliation(s)
- Takashi S T Tanaka
- Faculty of Life Science and Technology, Kunming University of Science and Technology, 727 Jingming Road (South), Chenggong New District, Kunming, Yunnan 650500, China; Graduate School of Agriculture, Kyoto University, Oiwake Kitashirakawa Sakyo, Kyoto, 606-8502, Japan
| | - Chagan Irbis
- Faculty of Life Science and Technology, Kunming University of Science and Technology, 727 Jingming Road (South), Chenggong New District, Kunming, Yunnan 650500, China.
| | - Yuki Hama
- Graduate School of Agriculture, Kyoto University, Oiwake Kitashirakawa Sakyo, Kyoto, 606-8502, Japan
| | - Pengyun Wang
- Kunming Agrometeorological Station, Xifu Road, Xishan District, Kunming, Yunnan 650500, China
| | - Kunzhi Li
- Faculty of Life Science and Technology, Kunming University of Science and Technology, 727 Jingming Road (South), Chenggong New District, Kunming, Yunnan 650500, China
| | - Tatsuya Inamura
- Graduate School of Agriculture, Kyoto University, Oiwake Kitashirakawa Sakyo, Kyoto, 606-8502, Japan
| |
Collapse
|
9
|
Litter Accumulation and Nutrient Content of Roadside Plant Communities in Sichuan Basin, China. PLANTS 2017; 6:plants6030036. [PMID: 28867780 PMCID: PMC5620592 DOI: 10.3390/plants6030036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 08/24/2017] [Accepted: 08/29/2017] [Indexed: 11/27/2022]
Abstract
It is widely recognized that feedbacks exist between plant litter and plant community species composition, but this relationship is difficult to interpret over heterogeneous conditions typical of modified environments such as roadways. Given the need to expedite natural recovery of disturbed areas through restoration interventions, we characterized litter accumulation and nutrient content (i.e., organic carbon, total N, and P) and quantified their association with key plant species. Plant species cover and litter characteristics were sampled at 18 successional forest plant communities along major roadways in Sichuan Basin, western China. Variation in litter across communities was assessed with principal component analysis (PCA) and species with the highest correlation to PCA axes were determined with Pearson’s r coefficients. Plant communities with the longest time since road construction (i.e., 70 years) were distinctly different in litter total N and organic carbon compared to plant communities with a shorter disturbance history. We encountered 59 plant species across sampling plots, but only four rare species (i.e., frequency < 5) were strongly correlated with litter characteristics (p < 0.01); none of which were the most abundant where they occurred. These results highlight the importance of site-specific factors (i.e., geographic location, disturbance age) regulating plant litter across heavily disturbed landscapes and how litter characteristics and rare plant species are correlated.
Collapse
|
10
|
Goodale CL. Multiyear fate of a 15 N tracer in a mixed deciduous forest: retention, redistribution, and differences by mycorrhizal association. GLOBAL CHANGE BIOLOGY 2017; 23:867-880. [PMID: 27564989 DOI: 10.1111/gcb.13483] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 07/11/2016] [Accepted: 07/25/2016] [Indexed: 05/11/2023]
Abstract
The impact of atmospheric nitrogen deposition on forest ecosystems depends in large part on its fate. Past tracer studies show that litter and soils dominate the short-term fate of added 15 N, yet few have examined its longer term dynamics or differences among forest types. This study examined the fate of a 15 N-NO3- tracer over 5-6 years in a mixed deciduous stand that was evenly composed of trees with ectomycorrhizal and arbuscular mycorrhizal associations. The tracer was expected to slowly mineralize from its main initial fate in litter and surface soil, with some 15 N moving to trees, some to deeper soil, and some net losses. Recovery of added 15 N in trees and litterfall totaled 11.3% both 1 and 5-6 years after the tracer addition, as 15 N redistributed from fine and especially coarse roots into cumulative litterfall and small accumulations in woody tissues. Estimates of potential carbon sequestration from tree 15 N recovery amounted to 12-14 kg C per kg of N deposition. Tree 15 N acquisition occurred within the first year after the tracer addition, with no subsequent additional net transfer of 15 N from detrital to plant pools. In both years, ectomycorrhizal trees gained 50% more of the tracer than did trees with arbuscular mycorrhizae. Much of the 15 N recovered in wood occurred in tree rings formed prior to the 15 N addition, demonstrating the mobility of N in wood. Tracer recovery rapidly decreased over time in surface litter material and accumulated in both shallow and deep soil, perhaps through mixing by earthworms. Overall, results showed redistribution of tracer 15 N through trees and surface soils without any losses, as whole-ecosystem recovery remained constant between 1 and 5-6 years at 70% of the 15 N addition. These results demonstrate the persistent ecosystem retention of N deposition even as it redistributes, without additional plant uptake over this timescale.
Collapse
Affiliation(s)
- Christine L Goodale
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, 14853, USA
| |
Collapse
|
11
|
Holgerson MA, Post DM, Skelly DK. Reconciling the role of terrestrial leaves in pond food webs: a whole‐ecosystem experiment. Ecology 2016; 97:1771-1782. [DOI: 10.1890/15-1848.1] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 01/28/2016] [Accepted: 02/15/2016] [Indexed: 11/18/2022]
Affiliation(s)
- Meredith A. Holgerson
- School of Forestry and Environmental Studies Yale University 370 Prospect Street New Haven Connecticut 06511 USA
| | - David M. Post
- Department of Ecology and Evolutionary Biology Yale University New Haven Connecticut 06511 USA
| | - David K. Skelly
- School of Forestry and Environmental Studies Yale University 370 Prospect Street New Haven Connecticut 06511 USA
| |
Collapse
|
12
|
Haddix ML, Paul EA, Cotrufo MF. Dual, differential isotope labeling shows the preferential movement of labile plant constituents into mineral-bonded soil organic matter. GLOBAL CHANGE BIOLOGY 2016; 22:2301-12. [PMID: 27142168 DOI: 10.1111/gcb.13237] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 12/16/2015] [Accepted: 01/03/2016] [Indexed: 05/07/2023]
Abstract
The formation and stabilization of soil organic matter (SOM) are major concerns in the context of global change for carbon sequestration and soil health. It is presently believed that lignin is not selectively preserved in soil and that chemically labile compounds bonding to minerals comprise a large fraction of the SOM. Labile plant inputs have been suggested to be the main precursor of the mineral-bonded SOM. Litter decomposition and SOM formation are expected to have temperature sensitivity varying with the lability of plant inputs. We tested this framework using dual (13) C and (15) N differentially labeled plant material to distinguish the metabolic and structural components within a single plant material. Big Bluestem (Andropogon gerardii) seedlings were grown in an enriched (13) C and (15) N environment and then prior to harvest, removed from the enriched environment and allowed to incorporate natural abundance (13) C-CO2 and (15) N fertilizer into the metabolic plant components. This enabled us to achieve a greater than one atom % difference in (13) C between the metabolic and structural components within the plant litter. This differentially labeled litter was incubated in soil at 15 and 35 °C, for 386 days with CO2 measured throughout the incubation. After 14, 28, 147, and 386 days of incubation, the soil was subsequently fractionated. There was no difference in temperature sensitivity of the metabolic and structural components with regard to how much was respired or in the amount of litter biomass stabilized. Only the metabolic litter component was found in the sand, silt, or clay fraction while the structural component was exclusively found in the light fraction. These results support the stabilization framework that labile plant components are the main precursor of mineral-associated organic matter.
Collapse
Affiliation(s)
- Michelle L Haddix
- Natural Resource Ecology Laboratory, Colorado State University, 200 West Lake Street, Fort Collins, CO, 80523-1499, USA
| | - Eldor A Paul
- Natural Resource Ecology Laboratory, Colorado State University, 200 West Lake Street, Fort Collins, CO, 80523-1499, USA
- Department of Soil and Crop Sciences, Colorado State University, 200 West Lake Street, Fort Collins, CO, 80523-1499, USA
| | - M Francesca Cotrufo
- Natural Resource Ecology Laboratory, Colorado State University, 200 West Lake Street, Fort Collins, CO, 80523-1499, USA
- Department of Soil and Crop Sciences, Colorado State University, 200 West Lake Street, Fort Collins, CO, 80523-1499, USA
| |
Collapse
|
13
|
Goodale CL, Fredriksen G, Weiss MS, McCalley K, Sparks JP, Thomas SA. Soil processes drive seasonal variation in retention of 15N tracers in a deciduous forest catchment. Ecology 2016; 96:2653-68. [PMID: 26649387 DOI: 10.1890/14-1852.1] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Seasonal patterns of stream nitrate concentration have long been interpreted as demonstrating the central role of plant uptake in regulating stream nitrogen loss from forested catchments. Soil processes are rarely considered as important drivers of these patterns. We examined seasonal variation in N retention in a deciduous forest using three whole-ecosystem 15N tracer additions: in late April (post-snowmelt, pre-leaf-out), late July (mid-growing- season), and late October (end of leaf-fall). We expected that plant 15N uptake would peak in late spring and midsummer, that immobilization in surface litter and soil would peak the following autumn leaf-fall, and that leaching losses would vary inversely with 15N retention. Similar to most other 15N tracer studies, we found that litter and soils dominated ecosystem retention of added 15N. However, 15N recovery in detrital pools varied tremendously by season, with > 90% retention in spring and autumn and sharply reduced 15N retention in late summer. During spring, over half of the 15N retained in soil occurred within one day in the heavy (mineral-associated) soil fraction. During summer, a large decrease in 15N retention one week after addition coincided with increased losses of 15NO3- to soil leachate and seasonal increases in soil and stream NO3- concentrations, although leaching accounted for only a small fraction of the lost 15N (< 0.2%). Uptake of 15N into roots did not vary by season and accounted for < 4% of each tracer addition. Denitrification or other processes that lead to N gas loss may have consumed the rest. These measurements of 15N movement provide strong evidence for the dominant role of soil processes in regulating seasonal N retention and losses in this catchment and perhaps others with similar soils.
Collapse
|
14
|
Hatton PJ, Castanha C, Torn MS, Bird JA. Litter type control on soil C and N stabilization dynamics in a temperate forest. GLOBAL CHANGE BIOLOGY 2015; 21:1358-67. [PMID: 25358112 DOI: 10.1111/gcb.12786] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 10/18/2014] [Indexed: 05/25/2023]
Abstract
While plant litters are the main source of soil organic matter (SOM) in forests, the controllers and pathways to stable SOM formation remain unclear. Here, we address how litter type ((13) C/(15) N-labeled needles vs. fine roots) and placement-depth (O vs. A horizon) affect in situ C and N dynamics in a temperate forest soil after 5 years. Litter type rather than placement-depth controlled soil C and N retention after 5 years in situ, with belowground fine root inputs greatly enhancing soil C (x1.4) and N (x1.2) retention compared with aboveground needles. While the proportions of added needle and fine root-derived C and N recovered into stable SOM fractions were similar, they followed different transformation pathways into stable SOM fractions: fine root transfer was slower than for needles, but proportionally more of the remaining needle-derived C and N was transferred into stable SOM fractions. The stoichiometry of litter-derived C vs. N within individual SOM fractions revealed the presence at least two pools of different turnover times (per SOM fraction) and emphasized the role of N-rich compounds for long-term persistence. Finally, a regression approach suggested that models may underestimate soil C retention from litter with fast decomposition rates.
Collapse
Affiliation(s)
- Pierre-Joseph Hatton
- School of Earth & Environmental Sciences, Queens College, CUNY, New York, NY, USA
| | | | | | | |
Collapse
|
15
|
The Carbon Cycle of a Maritime Ancient Temperate Broadleaved Woodland at Seasonal and Annual Scales. Ecosystems 2014. [DOI: 10.1007/s10021-014-9793-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
16
|
Scheibe A, Gleixner G. Influence of litter diversity on dissolved organic matter release and soil carbon formation in a mixed beech forest. PLoS One 2014; 9:e114040. [PMID: 25486628 PMCID: PMC4259385 DOI: 10.1371/journal.pone.0114040] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Accepted: 11/03/2014] [Indexed: 11/29/2022] Open
Abstract
We investigated the effect of leaf litter on below ground carbon export and soil carbon formation in order to understand how litter diversity affects carbon cycling in forest ecosystems. 13C labeled and unlabeled leaf litter of beech (Fagus sylvatica) and ash (Fraxinus excelsior), characterized by low and high decomposability, were used in a litter exchange experiment in the Hainich National Park (Thuringia, Germany). Litter was added in pure and mixed treatments with either beech or ash labeled with 13C. We collected soil water in 5 cm mineral soil depth below each treatment biweekly and determined dissolved organic carbon (DOC), δ13C values and anion contents. In addition, we measured carbon concentrations and δ13C values in the organic and mineral soil (collected in 1 cm increments) up to 5 cm soil depth at the end of the experiment. Litter-derived C contributes less than 1% to dissolved organic matter (DOM) collected in 5 cm mineral soil depth. Better decomposable ash litter released significantly more (0.50±0.17%) litter carbon than beech litter (0.17±0.07%). All soil layers held in total around 30% of litter-derived carbon, indicating the large retention potential of litter-derived C in the top soil. Interestingly, in mixed (ash and beech litter) treatments we did not find a higher contribution of better decomposable ash-derived carbon in DOM, O horizon or mineral soil. This suggest that the known selective decomposition of better decomposable litter by soil fauna has no or only minor effects on the release and formation of litter-derived DOM and soil organic matter. Overall our experiment showed that 1) litter-derived carbon is of low importance for dissolved organic carbon release and 2) litter of higher decomposability is faster decomposed, but litter diversity does not influence the carbon flow.
Collapse
Affiliation(s)
| | - Gerd Gleixner
- Max Planck Institute for Biogeochemistry, Jena, Germany
- * E-mail:
| |
Collapse
|
17
|
Variations in net litter nutrient input associated with tree species influence on soil nutrient contents in a subtropical evergreen broad-leaved forest. CHINESE SCIENCE BULLETIN-CHINESE 2013. [DOI: 10.1007/s11434-013-0019-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
18
|
Cheever BM, Webster JR, Bilger EE, Thomas SA. The relative importance of exogenous and substrate-derived nitrogen for microbial growth during leaf decomposition. Ecology 2013; 94:1614-25. [DOI: 10.1890/12-1339.1] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
19
|
Fahey TJ, Yavitt JB, Sherman RE, Maerz JC, Groffman PM, Fisk MC, Bohlen PJ. Earthworm effects on the incorporation of litter C and N into soil organic matter in a sugar maple forest. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2013; 23:1185-1201. [PMID: 23967585 DOI: 10.1890/12-1760.1] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
To examine the mechanisms of earthworm effects on forest soil C and N, we double-labeled leaf litter with 13C and 15N, applied it to sugar maple forest plots with and without earthworms, and traced isotopes into soil pools. The experimental design included forest plots with different earthworm community composition (dominated by Lumbricus terrestris or L. rubellus). Soil carbon pools were 37% lower in earthworm-invaded plots largely because of the elimination of the forest floor horizons, and mineral soil C:N was lower in earthworm plots despite the mixing of high C:N organic matter into soil by earthworms. Litter disappearance over the first winter-spring was highest in the L. terrestris (T) plots, but during the warm season, rapid loss of litter was observed in both L. rubellus (R) and T plots. After two years, 22.0% +/- 5.4% of 13C released from litter was recovered in soil with no significant differences among plots. Total recovery of added 13C (decaying litter plus soil) was much higher in no-worm (NW) plots (61-68%) than in R and T plots (20-29%) as much of the litter remained in the former whereas it had disappeared in the latter. Much higher percentage recovery of 15N than 13C was observed, with significantly lower values for T than R and NW plots. Higher overwinter earthworm activity in T plots contributed to lower soil N recovery. In earthworm-invaded plots isotope enrichment was highest in macroaggregates and microaggregates whereas in NW plots silt plus clay fractions were most enriched. The net effect of litter mixing and priming of recalcitrant soil organic matter (SOM), stabilization of SOM in soil aggregates, and alteration of the soil microbial community by earthworm activity results in loss of SOM and lowering of the C:N ratio. We suggest that earthworm stoichiometry plays a fundamental role in regulating C and N dynamics of forest SOM.
Collapse
Affiliation(s)
- Timothy J Fahey
- Department of Natural Resources, Cornell University, Fernow Hall, Ithaca, New York 14853-3001, USA.
| | | | | | | | | | | | | |
Collapse
|
20
|
|
21
|
Sardans J, Peñuelas J. The role of plants in the effects of global change on nutrient availability and stoichiometry in the plant-soil system. PLANT PHYSIOLOGY 2012; 160:1741-61. [PMID: 23115250 PMCID: PMC3510107 DOI: 10.1104/pp.112.208785] [Citation(s) in RCA: 126] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Accepted: 10/29/2012] [Indexed: 05/21/2023]
Affiliation(s)
- Jordi Sardans
- Consejo Superior de Investigaciones Científicas, Global Ecology Unit, Centre de Recerca Ecològica i Aplicacions Forestats-Centre d'Estudis Avançats de Blanes-Universitat Autònoma de Barcelona, Cerdanyola del Vallès 08913, Catalonia, Spain.
| | | |
Collapse
|