Earth:CO2 fertilization effect

From HandWiki
Short description: Fertilization from increased levels of atmospheric carbon dioxide


Top: the extent to which plant growth benefits from CO
2 in different areas (red=more positive impact.) Bottom: the impact on the main types of terrestrial biomes: evergreen broadleaf forests (EBFs), other forests (OF), short woody vegetation (SW), grasslands (GRA), croplands (CRO), plants with C4 carbon fixation and total.[1]

The CO2 fertilization effect or carbon fertilization effect causes an increased rate of photosynthesis while limiting leaf transpiration in plants. Both processes result from increased levels of atmospheric carbon dioxide (CO2).[2][3] The carbon fertilization effect varies depending on plant species, air and soil temperature, and availability of water and nutrients.[4][5] Net primary productivity (NPP) might positively respond to the carbon fertilization effect.[6] Although, evidence shows that enhanced rates of photosynthesis in plants due to CO2 fertilization do not directly enhance all plant growth, and thus carbon storage.[4] The carbon fertilization effect has been reported to be the cause of 44% of gross primary productivity (GPP) increase since the 2000s.[1] Earth System Models, Land System Models and Dynamic Global Vegetation Models are used to investigate and interpret vegetation trends related to increasing levels of atmospheric CO2.[4][7] However, the ecosystem processes associated with the CO2 fertilization effect remain uncertain and therefore are challenging to model.[8][9]

Terrestrial ecosystems have reduced atmospheric CO2 concentrations and have partially mitigated climate change effects.[10] The response by plants to the carbon fertilization effect is unlikely to significantly reduce atmospheric CO2 concentration over the next century due to the increasing anthropogenic influences on atmospheric CO2.[3][4][11][12] Earth's vegetated lands have shown significant greening since the early 1980s[13] largely due to rising levels of atmospheric CO2.[14][15][16][17]

Theory predicts the tropics to have the largest uptake due to the carbon fertilization effect, but this has not been observed. The amount of CO
2 uptake from CO
2 fertilization also depends on how forests respond to climate change, and if they are protected from deforestation.[18]

Changes in atmospheric carbon dioxide may reduce the nutritional quality of some crops, with for instance wheat having less protein and less of some minerals.[19]:439[20] Food crops could see a reduction of protein, iron and zinc content in common food crops of 3 to 17%.[21]

Mechanism

Main page: Earth:Photosynthesis

Through photosynthesis, plants use CO2 from the atmosphere, water from the ground, and energy from the sun to create sugars used for growth and fuel.[22] While using these sugars as fuel releases carbon back into the atmosphere (photorespiration), growth stores carbon in the physical structures of the plant (i.e. leaves, wood, or non-woody stems).[23] With about 19 percent of Earth's carbon stored in plants,[24] plant growth plays an important role in storing carbon on the ground rather than in the atmosphere. In the context of carbon storage, growth of plants is often referred to as biomass productivity.[23][25][26] This term is used because researchers compare the growth of different plant communities by their biomass, amount of carbon they contain.

Increased biomass productivity directly increases the amount of carbon stored in plants.[23] And because researchers are interested in carbon storage, they are interested in where most of the biomass is found in individual plants or in an ecosystem. Plants will first use their available resources for survival and support the growth and maintenance of the most important tissues like leaves and fine roots which have short lives.[27] With more resources available plants can grow more permanent, but less necessary tissues like wood.[27]

If the air surrounding plants has a higher concentration of carbon dioxide, they may be able to grow better and store more carbon[28] and also store carbon in more permanent structures like wood.[23] Evidence has shown this occurring for a few different reasons. First, plants that were otherwise limited by carbon or light availability benefit from a higher concentration of carbon.[29] Another reason is that plants are able use water more efficiently because of reduced stomatal conductance.[30] Plants experiencing higher CO2 concentrations may benefit from a greater ability to gain nutrients from mycorrhizal fungi in the sugar-for-nutrients transaction.[31] The same interaction can may also increase the amount of carbon stored in the soil by mycorrhizal fungi.[32]

Observations and trends

From 2002 to 2014, plants appear to have gone into overdrive, starting to pull more CO2 out of the air than they have done before.[33] The result was that the rate at which CO2 accumulates in the atmosphere did not increase during this time period, although previously, it had grown considerably in concert with growing greenhouse gas emissions.[33]

A 1993 review of scientific greenhouse studies found that a doubling of CO
2 concentration would stimulate the growth of 156 different plant species by an average of 37%. Response varied significantly by species, with some showing much greater gains and a few showing a loss. For example, a 1979 greenhouse study found that with doubled CO
2 concentration the dry weight of 40-day-old cotton plants doubled, but the dry weight of 30-day-old maize plants increased by only 20%.[34][35]

In addition to greenhouse studies, field and satellite measurements attempt to understand the effect of increased CO
2 in more natural environments. In free-air carbon dioxide enrichment (FACE) experiments plants are grown in field plots and the CO
2 concentration of the surrounding air is artificially elevated. These experiments generally use lower CO
2 levels than the greenhouse studies. They show lower gains in growth than greenhouse studies, with the gains depending heavily on the species under study. A 2005 review of 12 experiments at 475–600 ppm showed an average gain of 17% in crop yield, with legumes typically showing a greater response than other species and C4 plants generally showing less. The review also stated that the experiments have their own limitations. The studied CO
2 levels were lower, and most of the experiments were carried out in temperate regions.[36] Satellite measurements found increasing leaf area index for 25% to 50% of Earth's vegetated area over the past 35 years (i.e., a greening of the planet), providing evidence for a positive CO2 fertilization effect.[37][38]

Depending on environment, there are differential responses to elevated atmospheric CO2 between major 'functional types' of plant, such as C3 and C4 plants, or more or less woody species; which has the potential among other things to alter competition between these groups.[39][40] Increased CO2 can also lead to increased Carbon : Nitrogen ratios in the leaves of plants or in other aspects of leaf chemistry, possibly changing herbivore nutrition.[41] Studies show that doubled concentrations of CO2 will show an increase in photosynthesis in C3 plants but not in C4 plants.[42] However, it is also shown that C4 plants are able to persist in drought better than the C3 plants.[43]

Experimentation by enrichment

The effects of CO
2 enrichment can be most simply attained in a greenhouse (see Greenhouse § Carbon dioxide enrichment for its agricultural use). However, for experimentation, the results obtained in a greenhouse would be doubted due to it introducing too many confounding variables. Open-air chambers have been similarly doubted, with some critiques attributing, e.g., a decline in mineral concentrations found in these CO
2-enrichment experiments to constraints put on the root system. The current state-of-the art is the FACE methodology, where CO
2 is put out directly in the open field.[44] Even then, there are doubts over whether the results of FACE in one part of the world applies to another.[45]

Free-Air CO
2 Enrichment (FACE) experiments

The ORNL conducted FACE experiments where CO
2 levels were increased above ambient levels in forest stands.[46] These experiments showed:[47]

  • Increased root production stimulated by increased CO
    2    , resulting in more soil carbon.
  • An initial increase of net primary productivity, which was not sustained.
  • Faster decline in nitrogen availability in increased CO
    2     forest plots.
  • Change in plant community structure, with minimal change in microbial community structure.[48]
  • Enhanced CO
    2     cannot significantly increase the leaf carrying capacity or leaf area index of an area.[48]

FACE experiments have been criticized as not being representative of the entire globe. These experiments were not meant to be extrapolated globally. Similar experiments are being conducted in other regions such as in the Amazon rainforest in Brazil .[45]

Impacts on human nutrition

This section is an excerpt from Effects of climate change on agriculture#Reduced nutritional value of crops[ edit ]

See also

References

  1. ↑ 1.0 1.1 "CO2 fertilization of terrestrial photosynthesis inferred from site to global scales". Proceedings of the National Academy of Sciences of the United States of America 119 (10): e2115627119. March 2022. doi:10.1073/pnas.2115627119. PMID 35238668. Bibcode: 2022PNAS..11915627C. 
  2. ↑ "Inferring CO2 fertilization effect based on global monitoring land-atmosphere exchange with a theoretical model". Environmental Research Letters 15 (8): 084009. 2020-07-17. doi:10.1088/1748-9326/ab79e5. ISSN 1748-9326. Bibcode: 2020ERL....15h4009U. 
  3. ↑ 3.0 3.1 "Potential roles of CO2 fertilization, nitrogen deposition, climate change, and land use and land cover change on the global terrestrial carbon uptake in the twenty-first century" (in en). Climate Dynamics 52 (7–8): 4393–4406. April 2019. doi:10.1007/s00382-018-4388-8. ISSN 0930-7575. Bibcode: 2019ClDy...52.4393T. 
  4. ↑ 4.0 4.1 4.2 4.3 "Tree rings provide no evidence of a CO2 fertilization effect in old-growth subalpine forests of western Canada". Global Change Biology 25 (4): 1222–1234. December 2018. doi:10.1111/gcb.14561. PMID 30588740. Bibcode: 2019GCBio..25.1222H. 
  5. ↑ "How does carbon fertilization affect crop yield?". Environmental Research Letters. Aug 16, 2013. http://environmentalresearchweb.org/cws/article/news/54347. 
  6. ↑ "Large divergence of satellite and Earth system model estimates of global terrestrial CO2 fertilization" (in en). Nature Climate Change 6 (3): 306–310. March 2016. doi:10.1038/nclimate2879. ISSN 1758-678X. Bibcode: 2016NatCC...6..306K. 
  7. ↑ "Contrasting effects of CO2 fertilization, land-use change and warming on seasonal amplitude of Northern Hemisphere CO2 exchange" (in en). Atmospheric Chemistry and Physics 19 (19): 12361–12375. 2019-10-07. doi:10.5194/acp-19-12361-2019. ISSN 1680-7324. Bibcode: 2019ACP....1912361B. 
  8. ↑ "Leaf Area Index identified as a major source of variability in modelled CO2 fertilization". Biogeosciences 15 (22): 6909–6925. November 2018. doi:10.5194/bg-2018-213. 
  9. ↑ "The contributions of land-use change, CO
    2     fertilization, and climate variability to the Eastern US carbon sink: Partitioning of the Eastern US Carbon Sink" (in en). Global Change Biology 12 (12): 2370–2390. December 2006. doi:10.1111/j.1365-2486.2006.01254.x.     
  10. ↑ "Recent global decline of CO2 fertilization effects on vegetation photosynthesis". Science 370 (6522): 1295–1300. December 2020. doi:10.1126/science.abb7772. PMID 33303610. Bibcode: 2020Sci...370.1295W. https://repository.library.noaa.gov/view/noaa/54985. 
  11. ↑ "A decline in the carbon fertilization effect". Science 370 (6522): 1286.5–1287. 2020-12-11. doi:10.1126/science.370.6522.1286-e. Bibcode: 2020Sci...370S1286S. 
  12. ↑ "Does enhanced photosynthesis enhance growth? Lessons learned from CO
    2     enrichment studies"    . Plant Physiology 155 (1): 117–24. January 2011. doi:10.1104/pp.110.166819. PMID 21088226.     
  13. ↑ "Global Green Up Slows Warming" (in en). 2020-02-18. https://earthobservatory.nasa.gov/images/146296/global-green-up-slows-warming. 
  14. ↑ "Human Activity in China and India Dominates the Greening of Earth". 2019-02-08. http://www.nasa.gov/feature/ames/human-activity-in-china-and-india-dominates-the-greening-of-earth-nasa-study-shows. 
  15. ↑ "Greening of the Earth and its drivers". Nature Climate Change 6 (8): 791–795. 2016-08-01. doi:10.1038/nclimate3004. Bibcode: 2016NatCC...6..791Z. http://ir.igsnrr.ac.cn/handle/311030/43453. 
  16. ↑ "Carbon Dioxide Fertilization Greening Earth, Study Finds". 2016-04-25. http://www.nasa.gov/feature/goddard/2016/carbon-dioxide-fertilization-greening-earth. 
  17. ↑ "If you're looking for good news about climate change, this is about the best there is right now". Washington Post. https://www.washingtonpost.com/news/energy-environment/wp/2016/11/10/if-youre-looking-for-good-news-about-climate-change-this-is-about-the-best-there-is-right-now/. 
  18. ↑ "Effect of increasing CO
    2     on the terrestrial carbon cycle"    . Proceedings of the National Academy of Sciences of the United States of America 112 (2): 436–41. January 2015. doi:10.1073/pnas.1407302112. PMID 25548156. Bibcode: 2015PNAS..112..436S.     
  19. ↑ "Chapter 5: Food Security". Climate Change and Land: an IPCC special report on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems. 2019. https://www.ipcc.ch/site/assets/uploads/sites/4/2021/02/08_Chapter-5_3.pdf. 
  20. ↑ "Worries grow that climate change will quietly steal nutrients from major food crops". Science News. 13 December 2017. https://www.sciencenews.org/article/nutrition-climate-change-top-science-stories-2017-yir. 
  21. ↑ "Impact of anthropogenic CO2 emissions on global human nutrition" (in En). Nature Climate Change 8 (9): 834–839. 27 August 2018. doi:10.1038/s41558-018-0253-3. ISSN 1758-678X. Bibcode: 2018NatCC...8..834S. 
  22. ↑ (in en) The Path of Carbon in Photosynthesis (Report). Lawrence Berkeley National Laboratory. March 1948. pp. 884–922. https://escholarship.org/uc/item/9tk591mn. 
  23. ↑ 23.0 23.1 23.2 23.3 "Integrating the evidence for a terrestrial carbon sink caused by increasing atmospheric CO2". The New Phytologist 229 (5): 2413–2445. March 2021. doi:10.1111/nph.16866. PMID 32789857. 
  24. ↑ "Forests and Climate Change". http://www.fao.org/3/ac836e/AC836E03.htm#:~:text=At%20the%20global%20level,%2019,81%20percent%20in%20the%20soil. 
  25. ↑ "Improved biomass productivity and water use efficiency under water deficit conditions in transgenic wheat constitutively expressing the barley HVA1 gene". Plant Science 155 (1): 1–9. June 2000. doi:10.1016/S0168-9452(99)00247-2. PMID 10773334. 
  26. ↑ "Biomass, Productivity, Leaf Longevity, and Forest Structure in the Central Himalaya" (in en). Ecological Monographs 64 (4): 401–421. 1994. doi:10.2307/2937143. ISSN 1557-7015. Bibcode: 1994EcoM...64..401S. 
  27. ↑ 27.0 27.1 "Where does the carbon go? A model-data intercomparison of vegetation carbon allocation and turnover processes at two temperate forest free-air CO
    2     enrichment sites"    . The New Phytologist 203 (3): 883–99. August 2014. doi:10.1111/nph.12847. PMID 24844873.     
  28. ↑ "Decadal biomass increment in early secondary succession woody ecosystems is increased by CO2 enrichment". Nature Communications 10 (1): 454. February 2019. doi:10.1038/s41467-019-08348-1. PMID 30765702. Bibcode: 2019NatCo..10..454W. 
  29. ↑ "Effects of rising temperatures and [CO
    2     on the physiology of tropical forest trees"]. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences 363 (1498): 1811–7. May 2008. doi:10.1098/rstb.2007.0032. PMID 18267901.     
  30. ↑ "Reconciling the optimal and empirical approaches to modelling stomatal conductance" (in en). Global Change Biology 17 (6): 2134–2144. 2011. doi:10.1111/j.1365-2486.2010.02375.x. ISSN 1365-2486. Bibcode: 2011GCBio..17.2134M. 
  31. ↑ "Amazon forest response to CO2 fertilization dependent on plant phosphorus acquisition" (in en). Nature Geoscience 12 (9): 736–741. September 2019. doi:10.1038/s41561-019-0404-9. ISSN 1752-0908. Bibcode: 2019NatGe..12..736F. http://nora.nerc.ac.uk/id/eprint/524958/1/N524958PP.pdf. 
  32. ↑ "Organic nutrient uptake by mycorrhizal fungi enhances ecosystem carbon storage: a model-based assessment". Ecology Letters 14 (5): 493–502. May 2011. doi:10.1111/j.1461-0248.2011.01611.x. PMID 21395963. Bibcode: 2011EcolL..14..493O. 
  33. ↑ 33.0 33.1 "Study: Carbon-Hungry Plants Impede Growth Rate of Atmospheric CO
    2     | Berkeley Lab"    . 2016-11-08. http://newscenter.lbl.gov/2016/11/08/atmospheric-co2-pause/.     
  34. ↑ "Interspecific variation in the growth response of plants to an elevated ambient CO
    2     concentration"    . http://www.science.poorter.eu/1993_poorter_vegetatio.pdf.     
  35. ↑ "Elevated Partial Pressure of CO
    2     and Plant Growth". Oecologia 44 (1): 68–74. December 1979. doi:10.1007/BF00346400. PMID 28310466. Bibcode: 1979Oecol..44...68W.     
  36. ↑ "What have we learned from 15 years of free-air CO
    2     enrichment (FACE)? A meta-analytic review of the responses of photosynthesis, canopy properties and plant production to rising CO
    2    .". New Phytol. 165 (2): 351–71. February 2005. doi:10.1111/j.1469-8137.2004.01224.x. PMID 15720649.     
  37. ↑ "Greening of the Earth and its drivers". Nature Climate Change 6 (8): 791–95. August 2016. doi:10.1038/nclimate3004. ISSN 1758-6798. Bibcode: 2016NatCC...6..791Z. http://www.escholarship.org/uc/item/8mc6q011. "We show a persistent and widespread increase of growing season integrated LAI (greening) over 25% to 50% of the global vegetated area, whereas less than 4% of the globe shows decreasing LAI (browning). Factorial simulations with multiple global ecosystem models suggest that CO
    2     fertilization effects explain 70% of the observed greening trend".     
  38. ↑ "Carbon Dioxide Fertilization Greening Earth, Study Finds". NASA. 2016-04-25. https://www.nasa.gov/feature/goddard/2016/carbon-dioxide-fertilization-greening-earth. 
  39. ↑ Giam, Xingli; Bradshaw, Corey J.A.; Tan, Hugh T.W.; Sodhi, Navjot S. (July 2010). "Future habitat loss and the conservation of plant biodiversity". Biological Conservation 143 (7): 1594–1602. doi:10.1016/j.biocon.2010.04.019. ISSN 0006-3207. http://dx.doi.org/10.1016/j.biocon.2010.04.019. 
  40. ↑ Jeffrey S. Dukes; Harold A. Mooney (April 1999). "Does global change increase the success of biological invaders?". Trends Ecol. Evol. 14 (4): 135–9. doi:10.1016/S0169-5347(98)01554-7. PMID 10322518. 
  41. ↑ Gleadow RM (1998). "Enhanced CO2 alters the relationship between photosynthesis and defence in cyanogenic Eucalyptus cladocalyx F. Muell.". Plant Cell Environ. 21: 12–22. doi:10.1046/j.1365-3040.1998.00258.x. 
  42. ↑ HAMIM (December 2005). "Photosynthesis of C3 and C4 Species in Response to Increased CO 2 Concentration and Drought Stress". HAYATI Journal of Biosciences 12 (4): 131–138. doi:10.1016/s1978-3019(16)30340-0. ISSN 1978-3019. 
  43. ↑ Sternberg, Marcelo; Brown, Valerie K.; Masters, Gregory J.; Clarke, Ian P. (1999-07-01). "Plant community dynamics in a calcareous grassland under climate change manipulations" (in en). Plant Ecology 143 (1): 29–37. doi:10.1023/A:1009812024996. ISSN 1573-5052. https://doi.org/10.1023/A:1009812024996. 
  44. ↑ "Hidden shift of the ionome of plants exposed to elevated CO₂ depletes minerals at the base of human nutrition". eLife 3: e02245. May 2014. doi:10.7554/elife.02245. PMID 24867639. 
  45. ↑ 45.0 45.1 "Amazon FACE Experiment". ORNL. https://face.ornl.gov/AmazonFACE.html. 
  46. ↑ "Oak Ridge Experiment on CO
    2     Enrichment of Sweetgum: Experimental design"    . ORNL. Jun 29, 2009. https://face.ornl.gov/expdes.html.     
  47. ↑ "Free-Air CO
    2     Enrichment (FACE)"    . ORNL. https://climatechangescience.ornl.gov/content/free-air-co2.     
  48. ↑ 48.0 48.1 "Ecological Lessons from Free-Air CO
    2     Enrichment (FACE) Experiments". Annual Review of Ecology, Evolution, and Systematics 42 (1): 181–203. 2011. doi:10.1146/annurev-ecolsys-102209-144647. ISSN 1543-592X.     

External links



Retrieved from "https://handwiki.org/wiki/index.php?title=Earth:CO2_fertilization_effect&oldid=3294108"