ENVSCI 260 Global Environmental Change

Global Forests and carbon storage

1.

a. The two potential pathways for the carbon storage in trees after they die is firstly the plants do not respire and the carbon stored in the plants gets locked. The second pathway is when plants die the tress gets buried in the soil, the microbes that act on the tree and decompose releases carbon in to the soil (Cavanaugh et al., 2014).

The wood burial or the storage of carbon in the soil particle from the decomposing wood is a long term option of carbon burial. To describe this process, it is important to highlight that the forest acts as natural sink for atmospheric carbon. The photosynthetic activity performed by the plants leads to the storage of carbon into the plant cells. while this stored carbon again returns to the atmosphere through the respiration in plants. Thus, after a plant dies the carbon stored in trees is locked and wood gets buried in soil. The buried wood is then decomposed the soil microbes, carbon is released into the soil and gets stored for a longer period (Seto, Güneralp & Hutyra, 2012).

b. Forests take up carbon dioxide through the process of photosynthesis and the carbon is utilized in the biomass creation through the process of primary productivity. The carbon is then stored within the plant cells and a part of it released into the atmosphere through the deforestation, and decomposition. Carbon is stored within the old trees, top six inches of the soil and after a trees dies, the stored carbon is slowly released in to the atmosphere (Baccini et al., 2012).

2.

a.

Figure 1: Carbon flux (done by author)

b. The carbon flux out of the reservoir in the year 2040 will be 26.4 Mt C/year in case of out fluxes due to the insects and diseases. The out fluxes from the reservoir will be 15.6 Mt C/year in the year 2040 (Keenan et al., 2014).

c. Even if the doubling occurs after a period of 20 years, the system will still be at steady state because the incidence of the diseases and insects on the forest reserve will be natural process, the same will true for the forest which majorly occur due to natural reasons. The forest reservoir on the long run will reduce in reduce in quantity (Keenan et al., 2014).

3.

a. Considering the fact that the boreal forests is expanding, the overall effect on the size of the boreal forest will also expand geographically and the carbon reservoir will increase to 400 Gt C (Oechel et al., 2014).

b. If the size of the boreal forests is doubled over 50 years then the additional increase in the net flux of atmospheric carbon will be 1.3 Gt C/year (Oechel et al., 2014).

Extra credit: considering the increased spread of the boreal forests in to the artic regions, there will be increased heating effect of the atmosphere initially. However, as the time will progress the boreal forest will utilize sunlight to process increased photosynthetic activity. The increased carbon sequestration will reduce the atmospheric temperature (Oechel et al., 2014).

Planetary Energy Balance of our Neighbor Planets  

4.

Solar flux received by Venus is 662 W/m² and the solar flux received by Mercury is 2290 W/m². Thus, Mercury receives 1628 W/m² solar flux more than Venus (Welsh et al., 2012).

5.

a. The solar flux received by Mercury is much higher than the solar flux received by Venus. However, the factors of planetary energy balance affect the actual temperature of the planets (Wild et al., 2013).

b. the factors that affect the planetary energy balance is the distance of the planet from the sun, greenhouse effect and albedo. The factors that are responsible for the higher temperature on Venus in comparison to Mercury is albedo and greenhouse effect (Wild et al., 2013).

6.

a. The absorption spectrum of water vapour is wide ranging and it includes the ultraviolet radiations (<200 nm), infrared radiation (1 micron to 10 micron), far infrared (10 micrometre- 1 nanometre) and microwave (1 mm-10 cm). The absorption spectrum of water is very complex (Tahir & Amin, 2013).

The absorption spectrum of carbon dioxide includes infrared radiation in three different wavelengths of 2.7 micrometre, 4.3 micrometre and 15 micrometres. Thus, it is important to mention that both water vapour and carbon dioxide are potent absorbers of infrared radiation (Tahir & Amin, 2013).

b. The chemical structure and the bonding are the vital properties that render the molecules absorb the infrared radiation (Yu, Huang & Tan, 2012).

Nitrogen Cycle

7.

The nitrogen inputs here mean the rate at which the nitrogenous materials enter into the Lake Shelbyville per year. While, the denitrification rates mean the rate at which the nitrate is reduced and molecular nitrogen is produced (Bonnett et al., 2013).

Figure 2: Nitrogen reservoir (done by author)

8.

The total size of the nitrogen reservoir in the Lake Shelbyville is 3600 mg N/year (web.viu.ca., 2018).

References

Baccini, A. G. S. J., Goetz, S. J., Walker, W. S., Laporte, N. T., Sun, M., Sulla-Menashe, D., ... & Samanta, S. (2012). Estimated carbon dioxide emissions from tropical deforestation improved by carbon-density maps. Nature climate change, 2(3), 182.

Bonnett, S. A. F., Blackwell, M. S. A., Leah, R., Cook, V., O'connor, M., & Maltby, E. (2013). Temperature response of denitrification rate and greenhouse gas production in agricultural river marginal wetland soils. Geobiology, 11(3), 252-267.

Cavanaugh, K. C., Gosnell, J. S., Davis, S. L., Ahumada, J., Boundja, P., Clark, D. B., ... & Sheil, D. (2014). Carbon storage in tropical forests correlates with taxonomic diversity and functional dominance on a global scale. Global Ecology and Biogeography, 23(5), 563-573.

Keenan, T. F., Gray, J., Friedl, M. A., Toomey, M., Bohrer, G., Hollinger, D. Y., ... & Yang, B. (2014). Net carbon uptake has increased through warming-induced changes in temperate forest phenology. Nature Climate Change, 4(7), 598.

Oechel, W. C., Callaghan, T., Gilmanov, T., Holten, J. I., Maxwell, B., Molau, U., & Sveinbjörnsson, B. (Eds.). (2012). Global change and Arctic terrestrial ecosystems (Vol. 124). Springer Science & Business Media.

Seto, K. C., Güneralp, B., & Hutyra, L. R. (2012). Global forecasts of urban expansion to 2030 and direct impacts on biodiversity and carbon pools. Proceedings of the National Academy of Sciences, 109(40), 16083-16088.

Tahir, M., & Amin, N. S. (2013). Photocatalytic reduction of carbon dioxide with water vapors over montmorillonite modified TiO2 nanocomposites. Applied Catalysis B: Environmental, 142, 512-522.

web.viu.ca. (2018). More on Residence Times and Half-lifes. Retrieved from https://web.viu.ca/krogh/chem302/residence%20time.pdf

Welsh, W. F., Orosz, J. A., Carter, J. A., Fabrycky, D. C., Ford, E. B., Lissauer, J. J., ... & Torres, G. (2012). Transiting circumbinary planets Kepler-34 b and Kepler-35 b. Nature, 481(7382), 475.

Wild, M., Folini, D., Schär, C., Loeb, N., Dutton, E. G., & König-Langlo, G. (2013). The global energy balance from a surface perspective. Climate dynamics, 40(11-12), 3107-3134.

Yu, C. H., Huang, C. H., & Tan, C. S. (2012). A review of CO2 capture by absorption and adsorption. Aerosol Air Qual. Res, 12(5), 745-769.