Simulating the carbon balance of a temperate larch forest under various meteorological conditions

<p>Abstract</p> <p>Background</p> <p>Changes in the timing of phenological events may cause the annual carbon budget of deciduous forests to change. Therefore, one should take such events into account when evaluating the effects of global warming on deciduous forests. In this article, we report on the results of numerical experiments done with a model that includes a phenological module simulating the timing of bud burst and other phenological events and estimating maximum leaf area index.</p> <p>Results</p> <p>This study suggests that the negative effects of warming on tree productivity (net primary production) outweigh the positive effects of a prolonged growing season. An increase in air temperature by 3°C (5°C) reduces cumulative net primary production by 21.3% (34.2%). Similarly, cumulative net ecosystem production (the difference between cumulative net primary production and heterotrophic respiration) decreases by 43.5% (64.5%) when temperatures are increased by 3°C (5°C). However, the positive effects of CO₂enrichment (2 × CO₂) outweigh the negative effects of warming (<5°C).</p> <p>Conclusion</p> <p>Although the model was calibrated and validated for a specific forest ecosystem, the implications of the study may be extrapolated to deciduous forests in cool-temperate zones. These forests share common features, and it can be conjectured that carbon stocks would increase in such forests in the face of doubled CO₂and increased temperatures as long as the increase in temperature does not exceed 5°C.</p

The Effect of Affective State on Tactile Sensitivity

Infection from pathogens are the remaining threat that controls the human population and, evolutionarily speaking, the reproductive success of human beings. Past research demonstrates that disease avoidance encompasses not only a physiological response, but also that of a behavioural and psychological nature. There is bountiful research relating to disease avoidance behaviours being induced through indirect and direct exposure to disease salient stimuli and how the skin behaves as a barrier protecting the body. Jack Cotter (2011), attempted to identify a link hypothesizing that tactile sensitivity would increase, but did not gain significant results when testing disgust and two-point discrimination threshold using an aesthesiometer. The present study sought to modify and repeat Cotter's study. Forty participants completed the study consisting of exposure to neutral stimuli, a tactile sensitivity test, a distraction task, exposure to fear or disgust-related stimuli and then another tactile sensitivity test. T-tests and an ANOVA identified a significant change in tactile sensitivity with those induced in to pathogen disgust, as opposed to those induced in to fear. Slight gender differences identified were not concluded to be statistically significant. Repetition of the study with a larger sample could amend the short comings of this experiment, clarify the ambiguity still surrounding gender differences and distinction between fear and disgust-related stimuli, it may also increase the reliability of these results and equipment used

The role of land carbon sinks in mitigating global climate change

As evidence for the link between atmospheric greenhouse gases and climate change has increased, international efforts have focused on ways in which anthropogenic emissions of greenhouse gases, particularly carbon dioxide, can be reduced. However attempts to commit countries to reduce their emissions though the ratification of the 1997 Kyoto Protocol have been hampered by disagreement about the extent to which land carbon sinks should be considered in meeting these reduction commitments.The report highlights the considerable uncertainty in the scientific understanding of the causes, magnitude and permanence of the land carbon sink. While noting that the potential for human enhancement of the land carbon sink through changes in land management practices is finite in size and duration, it recommends that methods used in the production of forest and agricultural crops should be modified to reflect their short-term role in absorbing carbon dioxide. Reform of the European Unions Common Agricultural Policy could provide one opportunity to achieve this on agricultural land in Europe. With respect to the inclusion of land carbon sinks in the Kyoto Protocol, the report expresses concern that measurement techniques currently available are not sufficiently accurate to permit the reliable monitoring of any land carbon sinks that may be designated as part of such international agreements. The report concludes that projects designed to enhance land carbon sinks should not be allowed to divert financial and political resources away from long-term solutions to the problem of reducing the concentration of greenhouse gases in the atmosphere, namely the reduction in the use of fossil fuels