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Title: Global variations in ecosystem-scale isohydricity

 [1];  [2]
  1. Department of Earth and Environmental Engineering, Columbia University, New York NY 10027 USA, Department of Earth System Science, Stanford University, Stanford CA 94305 USA
  2. Department of Earth and Environmental Engineering, Columbia University, New York NY 10027 USA, Earth Institute, Columbia University, New York NY 10027 USA
Publication Date:
Sponsoring Org.:
OSTI Identifier:
Grant/Contract Number:
SC0011094; SC0014203
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Global Change Biology
Additional Journal Information:
Journal Volume: 23; Journal Issue: 2; Related Information: CHORUS Timestamp: 2017-10-20 16:10:15; Journal ID: ISSN 1354-1013
Country of Publication:
United Kingdom

Citation Formats

Konings, Alexandra G., and Gentine, Pierre. Global variations in ecosystem-scale isohydricity. United Kingdom: N. p., 2016. Web. doi:10.1111/gcb.13389.
Konings, Alexandra G., & Gentine, Pierre. Global variations in ecosystem-scale isohydricity. United Kingdom. doi:10.1111/gcb.13389.
Konings, Alexandra G., and Gentine, Pierre. 2016. "Global variations in ecosystem-scale isohydricity". United Kingdom. doi:10.1111/gcb.13389.
title = {Global variations in ecosystem-scale isohydricity},
author = {Konings, Alexandra G. and Gentine, Pierre},
abstractNote = {},
doi = {10.1111/gcb.13389},
journal = {Global Change Biology},
number = 2,
volume = 23,
place = {United Kingdom},
year = 2016,
month = 7

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1111/gcb.13389

Citation Metrics:
Cited by: 4works
Citation information provided by
Web of Science

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  • This paper presents the results of a project designed to integrate biogeographical and biogeochemical models of terrestrial ecosystem response to climatic change caused by increased emissions of greenhouse gases. Three biogeographical and three biogeochemical models were first compared independently of one another. Simulations were performed for the conterminous United States under conditions of current atmospheric carbon dioxide (CO{sub 2}) and climate, and doubled CO{sub 2} and various climates. For contemporary conditions, the biogeography models appropriately simulated the geographic distribution of major vegetation types and forest area. The results of biogeochemistry models were similar for net primary production and total carbonmore » storage under conditions of current climate. Variable model estimates resulted for input conditions of doubled CO{sub 2} due to differing model sensitivities to temperature and CO{sub 2}. When the biogeochemistry models were run in conjunction with the biogeographical models, variable results were also produced. The variability of model results indicates that ecosystem properties, particularly distribution of major vegetation types, primary productivity, and carbon storage, may be extremely sensitive to the magnitude of climatic change predicted by some models. However, the variation between models in magnitude and direction of change is considerable. Four broad areas of research are identified as deserving immediate attention: modularization of models, reduction of uncertainties regarding key processes, validation of models, and development of models of transient ecological responses. 89 refs., 6 figs., 10 tabs.« less
  • Longitudinal variations in the concentrations of four trace metals (Fe, Pb, Mn, and Zn) in soil solutions and streamwater were investigated at the Hubbard Brook Experimental Forest in the White Mountains of New Hampshire. The soils at Hubbard Brook are well-drained Spodosols. Concentrations of Pb and dissolved organic carbon (DOC) were elevated in soil solutions draining organic (Oa) horizons both in coniferous (red spruce, Picea rubens; balsam fir, Abies balsamea) and northern hardwood (yellow birch, Betula alleghaniensis; American beech, Fagus grandifolia; sugar maple, Acer saccharum) stands. In the coniferous zone, concentrations of Pb were high in streamwater, while DOC andmore » Fe concentrations were elevated in the lower mineral soil (Bs2) solutions and streamwater. In hardwood stands, reduced DOC concentrations in Bs2 soil solutions and streamwater relative Oa horizon concentrations coincided with lower concentrations of Fe and Pb, and apparent retention of these solutes in the mineral soil. Concentrations of Pb and Fe were highly correlated with DOC in soil solutions and streamwater suggesting that mobilization/immobilization of Pb and Fe were predominately controlled by transfer of DOC through complexation reactions. In contrast, concentrations of Mn and Zn were highest in streams and soil solutions in high-elevation hardwood stands. Elevated concentrations in deciduous vegetation and patterns of solution concentration suggest that vegetative cycling may be important in regulating transfer of Mn.« less
  • As time progresses, the world is changing in ways that are describable, but we are still unable to predict these changes with any degree of accuracy. Radiative and chemical properties of the atmosphere, global climate, and global ecology are dynamic and measurable, but they are also linked to each other in complex and poorly understood ways. While many of the physical and biological sub-processes are understood and modeled in great detail, predictive capabilities are poor if the linkages are not understood. Fortunately, linking of complex models across scientific disciplines (e.g., atmospheric chemistry-climate-agronomy-economics) to analyze large scale interactions has begun. 54more » refs.« less
  • Much current uncertainty surrounding the sensitivity to climatic change of natural vegetation in the USA is related to widely-varying approaches taken in constructing simulation models. Our goal was to reduce this uncertainty by coupling the biogeography model MAPSS (Mapped Atmosphere-Plant-Soil System) with critical ecosystem processes as simulated by TEM (Terrestrial Ecosystem Model). MAPSS predicts changes in leaf-area index (LAI) and vegetation biome boundaries using a site water balance model in conjunction with a physiologically-conceived rule-base model. On the other hand, TEM simulates equilibrium fluxes and pools of carbon (C) and nitrogen (N) such as net primary productivity (NPP) and availablemore » N without redistributing vegetation. In the coupled version of MAPSS presented here, these hydrological and biogeochemical processes are mutually constrained. For example, N availability may limit maximum LAI, and therefore, site water balance. Alternatively, actual evapotranspiration and soil water availability may modulate NPP via photosynthesis and net N mineralization. Initial results with this TEM-coupled version of MAPSS reveal significantly different patterns of NPP and vegetation distribution for the conterminous USA compared to those from uncoupled models, particularly at thermal and hydric extremes.« less
  • Alterations to the Earth`s environment are projected to be of an amplitude not experienced in the recent biological history. How ecosystems will respond to these changes is a matter of great uncertainty. Using the ecosystem model CENTURY, we evaluated the responses of five grass species, common to the Central Grasslands Region to changing climates. The altered climates used in this simulation, based on CCC GCM outputs, were 2.5 - 4{degrees}C increase in mean annual temperature and a 1% increase in mean annual precipitation with significant variation in seasonal distribution. The species included Agrostis scabra (C{sub 3} grass), Agropyron repens (C{submore » 3} grass), Poa pratensis (C{sub 3} grass), Schizachyrium scoparium (C{sub 4} grass), and Andropogon gerardii (C{sub 4} grass). Soil carbon decreased for all five species under the modified climate scenario. Annual production varied among species. Agropyron repens showed a slight increase, A. scabra showed a slight decrease, while the two C{sub 4} species, S. scoparium and A. gerardii, and the C{sub 3} invasive grass Poa pratensis showed larger increases in annual production. The increased annual production of P. pratensis under the modified climate scenario may indicate the potential for this species to further expand its range. What impact a range expansion of P. pratensis will have on ecosystem function and overall species composition is unclear.« less