scholarly journals Impact of Temperature Increase and Precipitation Alteration at Climate Change on Forest Productivity and Soil Carbon in Boreal Forest Ecosystems in Canada and Russia: Simulation Approach with the EFIMOD Model

Author(s):  
Oleg Chertov
2006 ◽  
Vol 86 (Special Issue) ◽  
pp. 171-185 ◽  
Author(s):  
Cindy Shaw ◽  
Oleg Chertov ◽  
Alexander Komarov ◽  
Jagtar Bhatti ◽  
Marina Nadporozhskaya ◽  
...  

Sustainability of forest ecosystems and climate change are two critical issues for boreal forest ecosystems in Canada that require an understanding of the links and balance between productivity, soil processes and their interaction with natural and anth ropogenic disturbances. Forest ecosystem models can be used to understand and predict boreal forest ecosystem dynamics. EFIMOD 2 is an individual tree model of the forest-soil ecosystem capable of modelling nitrogen feedback to productivity in response to changes in soil moisture and temperature. It has been successfully applied in Europe, but has not been calibrated for any forest ecosystem in Canada. The objective of this study was to parameterize and validate EFIMOD 2 for jack pine in Canada. Simulated and measured results agreed for changes in tree biomass carbon and soil carbon and nitrogen with increasing stand age and across a climatic gradient from the southern to northern limits of the boreal forest. Preliminary results from scenario testing indicate that EFIMOD 2 can be successfully applied to predict the impacts of forest management practices and climate change in the absence of natural disturbances on jack pine in the boreal forest of Canada. Model development is underway to represent the effects of natural disturbances. Key words: EFIMOD 2, forest soil, carbon, nitrogen, model, jack pine


2021 ◽  
Author(s):  
David Bysouth ◽  
Merritt Turetsky ◽  
Andrew Spring

<p>Climate change is causing rapid warming at northern high latitudes and disproportionately affecting ecosystem services that northern communities rely upon. In Canada’s Northwest Territories (NWT), climate change is impacting the access and availability of traditional foods that are critical for community health and well-being. With climate change potentially expanding the envelope of suitable agricultural land northward, many communities in the NWT are evaluating including agriculture in their food systems. However, the conversion of boreal forest to agriculture may degrade the carbon rich soils that characterize the region, resulting in large carbon losses to the atmosphere and the depletion of existing ecosystem services associated with the accumulation of soil organic matter. Here, we first summarize the results of 35 publications that address land use change from boreal forest to agriculture, with the goal of understanding the magnitude and drivers of carbon stock changes with time-since-land use change. Results from the literature synthesis show that conversion of boreal forest to agriculture can result in up to ~57% of existing soil carbon stocks being lost 30 years after land use change occurs. In addition, a three-way interaction with soil carbon, pH and time-since-land use change is observed where soils become more basic with increasing time-since-land use change, coinciding with declines in soil carbon stocks. This relationship is important when looking at the types of crops communities are interested in growing and the type of agriculture associated with cultivating these crops. Partnered communities have identified crops such as berry bushes, root vegetables, potatoes and corn as crops they are interested in growing. As berry bushes grow in acidic conditions and the other mentioned crops grow in more neutral conditions, site selection and management practices associated with growing these crops in appropriate pH environments will be important for managing soil carbon in new agricultural systems in the NWT. Secondly, we also present community scale soil data assessing variation in soil carbon stocks in relation to potential soil fertility metrics targeted to community identified crops of interest for two communities in the NWT.  We collected 192 soil cores from two communities to determine carbon stocks along gradients of potential agriculture suitability. Our field soil carbon measurements in collaboration with the partnered NWT communities show that land use conversions associated with agricultural development could translate to carbon losses ranging from 2.7-11.4 kg C/m<sup>2</sup> depending on the type of soil, agricultural suitability class, and type of land use change associated with cultivation. These results highlight the importance of managing soil carbon in northern agricultural systems and can be used to emphasize the need for new community scale data relating to agricultural land use change in boreal soils. Through the collection of this data, we hope to provide northern communities with a more robust, community scale product that will allow them to make informed land use decisions relating to the cultivation of crops and the minimization of soil carbon losses while maintaining the culturally important traditional food system.</p>


2000 ◽  
Vol 76 (1) ◽  
pp. 139-149 ◽  
Author(s):  
C. S. Papadopol

This paper summarizes current knowledge about the optical properties of greenhouse gases and general climate-warming influences. It explains the influence of this new phenomenon on the major ecosystems of the world, and considers the process of deforestation. It then analyzes the warming trends in Ontario based on data from two weather stations with continuous records of more than 120 years, to determine the rate of warming in the Great Lakes-St. Lawrence Region. The results indicate a temperature increase of about 0.76 °C per century and an 8% increase in annual total precipitation.Current climate change models indicate that for a scenario of 2 × CO2 levels some general, probable prognoses can be made, including a temperature increase of up to 4.5 °C, which might be disastrous for existing forest ecosystems. Specifically, the consequences of climate warming on (a) northward shifts of ecological conditions, (b) forest productivity, and (c) forest physiology and health, are examined. In the context of global warming, the paper then recommends practical management measures necessary to ensure adaptation of existing forest ecosystems to the warming that is already developing. These measures are intended to provide a no-risk environment for existing forests until rotation age. Next, a wide range of mitigative measures is examined with a view to securing the long-term preservation of forest ecosystems to avoid major ecological disruptions and, gradually, to reverse climate warming. Application of these measures requires international consensus, but countries that apply these recommendations first have a chance to profit from them due to the "CO2 fertilization" effect. Key words: climate change, silviculture, forest management


2014 ◽  
Vol 11 (16) ◽  
pp. 4477-4491 ◽  
Author(s):  
Y. He ◽  
Q. Zhuang ◽  
J. W. Harden ◽  
A. D. McGuire ◽  
Z. Fan ◽  
...  

Abstract. The large amount of soil carbon in boreal forest ecosystems has the potential to influence the climate system if released in large quantities in response to warming. Thus, there is a need to better understand and represent the environmental sensitivity of soil carbon decomposition. Most soil carbon decomposition models rely on empirical relationships omitting key biogeochemical mechanisms and their response to climate change is highly uncertain. In this study, we developed a multi-layer microbial explicit soil decomposition model framework for boreal forest ecosystems. A thorough sensitivity analysis was conducted to identify dominating biogeochemical processes and to highlight structural limitations. Our results indicate that substrate availability (limited by soil water diffusion and substrate quality) is likely to be a major constraint on soil decomposition in the fibrous horizon (40–60% of soil organic carbon (SOC) pool size variation), while energy limited microbial activity in the amorphous horizon exerts a predominant control on soil decomposition (>70% of SOC pool size variation). Elevated temperature alleviated the energy constraint of microbial activity most notably in amorphous soils, whereas moisture only exhibited a marginal effect on dissolved substrate supply and microbial activity. Our study highlights the different decomposition properties and underlying mechanisms of soil dynamics between fibrous and amorphous soil horizons. Soil decomposition models should consider explicitly representing different boreal soil horizons and soil–microbial interactions to better characterize biogeochemical processes in boreal forest ecosystems. A more comprehensive representation of critical biogeochemical mechanisms of soil moisture effects may be required to improve the performance of the soil model we analyzed in this study.


Author(s):  
Rim Khlifa ◽  
Daniel Houle ◽  
Hubert Morin ◽  
Steven Kembel

Phyllosphere microbial communities have received considerable attention given their important influence on their plant hosts and on ecosystem functioning. In a context where climate change threatens the sustainability of ecosystems, it is important to understand how phyllosphere microbes will respond to changes in their environment. We used 16S rRNA gene amplicon sequencing to quantify phyllosphere bacterial communities of black spruce exposed to nitrogen canopy enrichment and soil warming in the boreal forest of Quebec, Canada. The treatments were applied from April to September 2015 and the sampling was done in September. Neither treatment influenced the overall community structure and diversity of black spruce phyllosphere bacterial communities. However, some bacterial taxa and inferred microbial functions did differ among treatments, revealing in particular a stronger response of some bacteria to soil warming rather than nitrogen enrichment. Our results suggest that soil warming could potentially induce more changes in phyllosphere bacterial taxa abundances and functions than nitrogen addition, with potential consequences for microbial diversity and boreal forest ecosystem function under likely climate change scenarios. Our study suggests avenues for further research to integrate a more mechanistic understanding of the importance of phyllosphere microbes for black spruce and boreal forest ecosystems.


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