Assessment of Grassland and Ecosystem Responses to Atmospheric Change Using Linked Plant-Soil Process Models

1997 ◽  
Vol 7 (3) ◽  
pp. 802 ◽  
Author(s):  
Michael B. Coughenour ◽  
De-Xing Chen
Keyword(s):  
Process Models ◽  
Ecosystem Responses ◽  
Atmospheric Change ◽  
Plant Soil ◽  
Soil Process

Carbon flux response and recovery to drought years in a hemi-boreal peat bog between different vegetation types

2020 ◽  
Author(s):  
Chris R Taylor ◽  
Ben Keane ◽  
Iain Hartley ◽  
Gareth Phoenix
Keyword(s):  
Carbon Dioxide ◽  
Nutrient Availability ◽  
Anthropogenic Activities ◽  
Terrestrial Ecosystems ◽  
Phosphorus Limitation ◽  
Atmospheric Concentration ◽  
Ecosystem Responses ◽  
N Limitation ◽  
Plant Soil ◽  
P Limitation

<p>Terrestrial ecosystems absorb 30% of anthropogenic carbon dioxide (CO<sub>2</sub>) emissions, slowing its rising atmospheric concentration and substantially inhibiting climate change. This uptake is believed to be due to elevated CO<sub>2</sub> (eCO<sub>2</sub>) stimulating plant photosynthesis and growth, thus increasing carbon (C) storage in plants and soil organic matter. However, nitrogen (N) limitation can reduce ecosystem C uptake capacity under eCO<sub>2</sub> by as much as 50%. Phosphorus (P) limitation in ecosystems is almost as common as N-limitation and is increasing due to ongoing deposition of N from anthropogenic activities. Despite this, we do not know how P-limited ecosystems will respond to eCO<sub>2</sub>, constituting a major gap in our understanding of how large areas of the biosphere will impact atmospheric CO<sub>2</sub> over the coming decades.</p><p>In the first study conducted into the effect of eCO<sub>2</sub> on P-limited ecosystems with manipulated nutrient availability, the Phosphorus Limitation And ecosystem responses to Carbon dioxide Enrichment project (PLACE), investigates the effects of eCO<sub>2</sub> on C cycling in grasslands, which are a critical global C store. Turf mesocosms from P-limited acidic and limestone grasslands, where N and P inputs have been manipulated for 20 years (control, low N (3.5 g m<sup>-2</sup> y<sup>-1</sup>), high N (14 g m<sup>-2</sup> y<sup>-1</sup>), and P (3.5 g m<sup>-2</sup> y<sup>-1</sup>)), have been exposed to either ambient or eCO<sub>2</sub> (600 ppm) in a miniFACE (mini Free Air Carbon Enrichment) system. Long-term P addition has alleviated P limitation while N additions have exacerbated it. The two contrasting grasslands contain different amounts of organic versus mineral P in their soils and, thus, plants may have to use contrasting strategies to acquire the additional P they need to increase growth rates under elevated CO<sub>2</sub>.</p><p>We present data from the first two growing seasons, including above and below ground productivity, and C, N and P cycling through plant, soil and microbial pools. Aboveground harvest data from the second year have shown eCO<sub>2</sub> has only increased biomass production in the limestone grassland (by 17%; p< 0.0001), and not in the acid grassland. There was also a significant effect of nutrient treatment (p< 0.001) with biomass increasing under P and HN, indicating some co-NP limitation. Stable isotope tracing, using the fumigation CO<sub>2</sub> signal has shown the fate of newly assimilated C and its contribution to gaseous C flux to the atmosphere in the form of methane (CH<sub>4</sub>) and respired CO<sub>2</sub>.  In summary, our first two years of eCO<sub>2</sub> treatment suggests that productivity of limestone and acidic grassland respond differently and that these responses depend on nutrient availability, indicating the complexity of predicting P-limited ecosystem responses as atmospheric CO<sub>2 </sub>continues to rise.</p>

On effective linearity of soil process models

2008 ◽  
Vol 59 (5) ◽  
pp. 990-999 ◽  
Author(s):  
R. Corstanje ◽  
R. M. Lark
Keyword(s):  
Process Models ◽  
Soil Process

scholarly journals Asynchronous nitrogen supply and demand produce nonlinear plant allocation responses to warming and elevated CO2

2019 ◽  
Vol 116 (43) ◽  
pp. 21623-21628 ◽  
Author(s):  
Genevieve L. Noyce ◽  
Matthew L. Kirwan ◽  
Roy L. Rich ◽  
J. Patrick Megonigal
Keyword(s):  
Climate Change ◽  
Supply And Demand ◽  
Terrestrial Ecosystem ◽  
Root Production ◽  
Plant Responses ◽  
Ecosystem Responses ◽  
Plant Nitrogen ◽  
Global Trends ◽  
Plant Soil ◽  
Plant Allocation

Terrestrial ecosystem responses to climate change are mediated by complex plant–soil feedbacks that are poorly understood, but often driven by the balance of nutrient supply and demand. We actively increased aboveground plant-surface temperature, belowground soil temperature, and atmospheric CO2 in a brackish marsh and found nonlinear and nonadditive feedbacks in plant responses. Changes in root-to-shoot allocation by sedges were nonlinear, with peak belowground allocation occurring at +1.7 °C in both years. Above 1.7 °C, allocation to root versus shoot production decreased with increasing warming such that there were no differences in root biomass between ambient and +5.1 °C plots in either year. Elevated CO2 altered this response when crossed with +5.1 °C, increasing root-to-shoot allocation due to increased plant nitrogen demand and, consequently, root production. We suggest these nonlinear responses to warming are caused by asynchrony between the thresholds that trigger increased plant nitrogen (N) demand versus increased N mineralization rates. The resulting shifts in biomass allocation between roots and shoots have important consequences for forecasting terrestrial ecosystem responses to climate change and understanding global trends.

Soil Ecology

Ecology ◽  
2012 ◽  
Author(s):  
Franciska T. De Vries ◽  
Richard D. Bardgett
Keyword(s):  
Global Change ◽  
New Technologies ◽  
Terrestrial Ecosystem ◽  
Terrestrial Ecosystems ◽  
Soil Ecology ◽  
Biological Interactions ◽  
Soil Biodiversity ◽  
Ecosystem Responses ◽  
Plant Soil

The study of soil ecology has a long tradition. Most of this interest, until relatively recently, has been from an agricultural perspective, but now it is widely accepted that soil ecology is central to the study of terrestrial ecology. Early research in soil ecology was largely descriptive, detailing the abundance of diversity of organisms in soils of different habitats. However, interest in functional soil ecology started in the 1980s with studies of trophic interactions in soil and their importance for nutrient cycles and decomposition. Now, the topic has blossomed, with the help of new technologies that allow the study of soil organisms and their activities in situ, and there is currently widespread recognition that soil ecology is fundamental to our understanding of the functioning of terrestrial ecosystems and their response to global change. Today, the field of soil ecology is dominated by discussions on the use of new molecular tools that enable ecologists to understand what regulates patterns of diversity in soil, the functional role of soil biodiversity and plant-soil interactions, especially those that occur at the root-soil interface, and the role of soil biological communities in regulating ecosystem responses to global change, including the global carbon cycle under climate change. Many challenges still remain in soil ecology, and perhaps the most significant is the need for a stronger theoretical basis for the subject; almost all studies in this area have been carried out from an empirical perspective, and modeling approaches are still in their infancy. As a consequence, our ability to make predictions about the role of soil biological interactions and feedbacks in regulating terrestrial ecosystem processes and their response to global change remains limited.

scholarly journals Ecosystem responses to elevated CO2 governed by plant-soil interactions and the cost of nitrogen acquisition

2017 ◽  
Vol 217 (2) ◽  
pp. 507-522 ◽  
Author(s):  
César Terrer ◽  
Sara Vicca ◽  
Benjamin D. Stocker ◽  
Bruce A. Hungate ◽  
Richard P. Phillips ◽  
...  
Keyword(s):  
Elevated Co2 ◽  
Ecosystem Responses ◽  
Nitrogen Acquisition ◽  
Plant Soil ◽  
The Cost ◽  
Plant Soil Interactions

Identifying suboptimalities with factorial model comparison

2018 ◽  
Vol 41 ◽  
Author(s):  
Wei Ji Ma
Keyword(s):  
Experimental Design ◽  
Model Comparison ◽  
Process Models ◽  
Multiple Forms ◽  
Factorial Experimental Design ◽  
Factorial Model ◽  
Multiple Components ◽  
The Many

AbstractGiven the many types of suboptimality in perception, I ask how one should test for multiple forms of suboptimality at the same time – or, more generally, how one should compare process models that can differ in any or all of the multiple components. In analogy to factorial experimental design, I advocate for factorial model comparison.

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