Modelling climate change impacts on crop production for food security

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How to achieve higher yield levels in North Savo – means and challenges indicated by farmers.

Sustainable intensification of Nordic farming systems is seen as an effective adaptation and mitigation strategy. Two stakeholder workshops targeting sustainable farming under changing climate were arranged in North Savo, Finland in 2014 and 2016 with farmers and other regional agricultural stakeholder participants. Workshop outcomes are presented and discussed.The most important changes in the operational environment of farms in North Savo during past decades, identified by the participants, were related to agricultural policies and subsidy systems. They were seen strongly supporting extensification and undermining motivation for yield improvements. Long-term trends in weather patterns were not taken up by farmers. The most important obstacles for higher yields mentioned were soil fertility, particularly in relation to soil compaction and insufficient drainage, but also low motivation for improvements and lack of know-how.Workshop participants identified improving soil fertility with drainage and liming, improved crop rotations, better sowing techniques including overseeding, careful selection of cultivars and forage grass mixtures as important means for higher crop yields. Suggested solutions for improving both crop yields and farm economy were to 1) increase collaboration among farmers, 2) focus only on the most productive fields and 3) actively develop farming skills.The workshops provided important perspectives on future farming development, as well as needed developments of model-based integrated assessments which must reliably reflect the impacts of different management actions on yields, environment and farm economy. The challenge is also to correctly describe the impacts of increasing collaboration and cost sharing among farmers

Simulating impacts of climate and management on timothy growth in Northern countries

201

A modelling framework for the assessment of the impacts of alternative policy and management options on the sustainability of Finnish agrifood systems

Recently, a new project focussing on integrated assessment modelling of agrifood systems (IAM-Tools) has been launched at MTT Agrifood Research Finland to gather, evaluate, refine and develop these component models and to link tem in an IAM framework for Finnish conditions

Immune activation in the small intestine in patients with rheumatoid arthritis

Objectives: To determine whether inflammation in the gut associated immune system is activated in rheumatoid arthritis ( RA). The expression of chemokine receptor- (CCR4, CCR5) and cytokine- ( interleukin (IL) 2, IL10, interferon gamma (IFNgamma), tumour necrosis factor alpha (TNFalpha), and transforming growth factor beta (TGFbeta)) specific mRNA in intestinal biopsy samples from patients with RA was examined. Methods: Duodenal biopsy samples from 13 patients with RA and 15 control subjects were studied. The mRNA expression of CCR4, CCR5, IL2, IL10, IFNgamma, TNFalpha, and TGFb in intestinal biopsy samples was demonstrated by real time quantitative reverse transcriptase-polymerase chain reaction. Results: The mRNA expression of CCR4, CCR5, and IL10 in intestinal biopsy samples was increased in patients with RA in comparison with control subjects ( p = 0.001, p = 0.046, p = 0.019). No difference in the expression levels of IL2, IFNgamma, TNFalpha, or TGFbeta was seen between patients with RA and controls. Conclusions: The increased intestinal mRNA expression of IL10, CCR5, and CCR4 suggests that gut associated immune cells are activated in patients with RA.Peer reviewe

Specialization and optimization of constraint programs with dynamic scheduling

In this report we discuss some of the issues involved in the specialization and optimization of constraint logic programs with dynamic scheduling. Dynamic scheduling, as any other form of concurrency, increases the expressive power of constraint logic programs, but also introduces run-time overhead. The objective of the specialization and optimization is to reduce as much as possible such overhead automatically, while preserving the semantics of the original programs. This is done by program transformation based on global analysis. We present implementation techniques for this purpose and report on experimental results obtained from an implementation of the techniques in the context of the CIAO compiler

Leaf litter decomposition -- Estimates of global variability based on Yasso07 model

Litter decomposition is an important process in the global carbon cycle. It accounts for most of the heterotrophic soil respiration and results in formation of more stable soil organic carbon (SOC) which is the largest terrestrial carbon stock. Litter decomposition may induce remarkable feedbacks to climate change because it is a climate-dependent process. To investigate the global patterns of litter decomposition, we developed a description of this process and tested the validity of this description using a large set of foliar litter mass loss measurements (nearly 10 000 data points derived from approximately 70 000 litter bags). We applied the Markov chain Monte Carlo method to estimate uncertainty in the parameter values and results of our model called Yasso07. The model appeared globally applicable. It estimated the effects of litter type (plant species) and climate on mass loss with little systematic error over the first 10 decomposition years, using only initial litter chemistry, air temperature and precipitation as input variables. Illustrative of the global variability in litter mass loss rates, our example calculations showed that a typical conifer litter had 68% of its initial mass still remaining after two decomposition years in tundra while a deciduous litter had only 15% remaining in the tropics. Uncertainty in these estimates, a direct result of the uncertainty of the parameter values of the model, varied according to the distribution of the litter bag data among climate conditions and ranged from 2% in tundra to 4% in the tropics. This reliability was adequate to use the model and distinguish the effects of even small differences in litter quality or climate conditions on litter decomposition as statistically significant.Comment: 19 Pages, to appear in Ecological Modellin

The impacts of increased heat stress events on wheat yield under climate change in China

China is the largest wheat producing country in the world. Wheat is one of the two major staple cereals consumed in the country and about 60% of Chinese population eats the grain daily. To safeguard the production of this important crop, about 85% of wheat areas in the country are under irrigation or high rainfall conditions. However, wheat production in the future will be challenged by the increasing occurrence and magnitude of adverse and extreme weather events. In this paper, we present an analysis that combines outputs from a wide range of General Circulation Models (GCMs) with observational data to produce more detailed projections of local climate suitable for assessing the impact of increasing heat stress events on wheat yield. We run the assessment at 36 representative sites in China using the crop growth model CSM-CropSim Wheat of DSSAT 4.5. The simulations based on historical data show that this model is suitable for quantifying yield damages caused by heat stress. In comparison with the observations of baseline 1996-2005, our simulations for the future indicate that by 2100, the projected increases in heat stress would lead to an ensemble-mean yield reduction of –7.1% (with a probability of 80%) and –17.5% (with a probability of 96%) for winter wheat and spring wheat, respectively, under the irrigated condition. Although such losses can be fully compensated by CO2 fertilization effect as parameterized in DSSAT 4.5, a great caution is needed in interpreting this fertilization effect because existing crop dynamic models are unable to incorporate the effect of CO2 acclimation (the growth enhancing effect decreases over time) and other offsetting forces