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Tag: plants

Changes to Plant Flowering Times – Forgettable or Regrettable?

Posted on by Eleanor Pike

By Eleanor Pike

On average the date that a plant first flowers is moving earlier in spring for 385 British plant species (Fitter & Fitter, 2002). This could be due to global warming making winters warmer, and tricking the plants into thinking spring has come earlier (Post et al, 2001). Global warming is a global climate change trend seen in recent years due to the excessive release of greenhouse gasses by humanity. These gasses are released through burning of fossil fuels like petrol (Hansen, 1998).

So why should we be concerned about this? Flowering plants can be important for a number of reasons. Seen here in Figure 1 is a flowering courgette plant (Cucurbita pepo var. cylindrical) which illustrates how crucial flowering plants can be with regards to providing food. Flowers are the plants sex organs which allow fertilisation of the plant to produce the fruit and vegetables that we eat (Lord & Russell, 2002). This is how plants reproduce normally though humanity has harnessed this to create crops to eat. The world is already facing severe changes and concerns with regards to feeding the growing global population.

Pollinators facilitate this fertilisation process through a number of mechanisms. The importance of these pollinators cannot be questioned, with 35% of crops relying on animal pollinators to produce fruits, vegetables or seeds (Klein et al, 2007). However if plants are flowering earlier, could it be that in enough time, there is a concerning distinction between when plants flower and when pollinators are most active?

One of the most important pollinators are bees due to their specific foraging behaviours and consistency (Corbet et al, 1991). Bees are already facing many challenges to do with emerging global change, and their decline is a large concern economically and ecologically. Bee decline has also been linked to the decline of plant species that rely on bees to reproduce (Biesmeijer et al, 2006). This is yet further evidence that the synchronicity between pollinators and plant flowering times could become a real cause for concern in the near future. There are many challenges being faced by global change scientists in modern times, and early flowering times is one of them.

Word Count: 372

References

Biesmeijer, J. et al., 2006. Parallel Declines in Pollinators and Insect-Pollinated Plants in Britain and the Netherlands. Science, 313(5785).

Corbet, S., Williams, I. & Osborne, J., 1991. Bees and the Pollination of Crops and Wild Flowers in the European Community. Bee World, 72(2), pp. 47-59.

Fitter, A. & Fitter, R., 2002. Rapid Changes in Flowering Time in British Plants. Science, 296(1689).

Hansen, J., 1998. Sir John Houghton: Global Warming: The Complete Briefing, 2nd edition. Journal of Atmospheric Chemistry, 30(409).

Klein, A. et al., 2007. Importance of pollinators in changing landscapes for world crops. Proceedings of the Royal Society- Biological Sciences, 274(1608).

Lord, E. & Russell, S., 2002. The Mechanisms of Pollination and Fertilization in Plants. Annual Review of Cell and Developmental Biology, Volume 18, pp. 81-105.

Post, E., Forchhammer, M., Stenseth, N. & Callaghan, T., 2001. The timing of life-history events in a changing climate.. Proceedings of the Royal Society: Biological Sciences, 268(1462), pp. 15-23.

 

 

Figure 1: Flowering courgette plant (https://static1.squarespace.com/static/563cf214e4b021af1b575f8a/t/56aabc8859b1f8f179bf570f/1456894203178/flower-on-zucchini-plant.jpg)
Figure 1: Flowering courgette plant (https://static1.squarespace.com/static/563cf214e4b021af1b575f8a/t/56aabc8859b1f8f179bf570f/1456894203178/flower-on-zucchini-plant.jpg)


Rise of the planet of the grapes: climate change through rosé-tinted glasses?

Posted on by Eleanor Davis

 

images
Source: French Country Wines

Chardonnay, Ortega, Pinot Noir…the UK produces over 5 million bottles of wine a year (English Wine Producers, 2015). But given the changes in climate occurring across the globe, this production is said to be on the up.

An increasingly hot topic in the media, the numerous negative consequences of global warming such as extreme weather events and rising sea levels are oftendiscussed. However, the resultant increases in average annual temperature and atmospheric CO2 concentrations have opened a window of opportunity for the UK wine industry. This increased wine production in England and Wales is now touted as the unexpected silver lining to climate change’s storm cloud.

With a predicted temperature increase of 2.2 degrees Celsius in the UK by 2100 (MetOffice, 2011), the success of grape varieties in Britain is a perfect example of the ways in which global environmental change can impact plant function.

Climate is a critical factor in viticulture (the growing of wine grapes) and increased levels of atmospheric CO2 have been shown to increase plant growth (Jakobsen et al. 2016). Bindi et al (2001) found that elevated atmospheric CO2 levels had a significant effect on the grapevine Vitis vinifera total fruit weight, leading to an increase in biomass of up to 45%. This is also the case for many other crop and wild plant species with 79 species reviewed by Jablonski et al (2002) producing more flowers, more seeds and a greater total mass.

This increased growth in response to elevated atmospheric CO2 can be attributed to plants fixing the CO2 through photosynthesis – the process through which plants produce glucose from carbon dioxide and water. Increased abundance of CO2 in the atmosphere leads to increased carbon fixation and hence more growth (Drake et al. 1997). As global warming trends continue, it is expected that many crops will exhibit increased growth rates as CO2 conditions become increasingly favourable.

However, whilst viticulture in the UK are experiencing a boom, vineyards elsewhere are struggling. For example, many grape varieties in Australia are no longer able to grow due to ongoing environmental change (Mozell & Thach, 2014). This is partly because whilst the atmospheric CO2 increase occurring is favourable for many crops, other factors such as temperature increase are not.

Temperature is a major determinant of plant development and can lead to reduced yield in crops by shortening the plants’ development stages (Craufurd &Wheeler, 2009). Increased temperatures can also vastly reduce the land area suitable for the growth of certain crops (Hannah et al, 2013). This reflects the reality of Australian viticulture at present and represents a threat to the future of many other crop species.

Ultimately, “wine grape production provides a good test case for measuring indirect impacts […] because viticulture is sensitive to climate” (Hannah et al, 2013). As such, it is important to continue investigating the impacts of environmental change on plants as it is possible that the success of viticulture in the UK represents the rise before the fall.

[497 words]

References:

Bindi, M., Fibbi, L. and Miglietta, F., 2001. Free Air CO 2 Enrichment (FACE) of grapevine (Vitis vinifera L.): II. Growth and quality of grape and wine in response to elevated CO 2 concentrations. European Journal of Agronomy, 14(2), pp.145-155.

Craufurd, P.Q. and Wheeler, T.R., 2009. Climate change and the flowering time of annual crops. Journal of Experimental Botany, 60(9), pp.2529-2539.

Drake, B.G., Gonzàlez-Meler, M.A. and Long, S.P., 1997. More efficient plants: a consequence of rising atmospheric CO2?. Annual review of plant biology, 48(1), pp.609-639.

English Wine Producers, 2015. English Wine Industry: Statistics, Facts and Figures. Available online at http://www.englishwineproducers.co.uk/background/stats/ [Accessed 17th March 2017]

Hannah, L., Roehrdanz, P.R., Ikegami, M., Shepard, A.V., Shaw, M.R., Tabor, G., Zhi, L., Marquet, P.A. and Hijmans, R.J., 2013. Climate change, wine, and conservation. Proceedings of the National Academy of Sciences, 110(17), pp.6907-6912.

Jablonski, L.M., Wang, X. and Curtis, P.S., 2002. Plant reproduction under elevated CO2 conditions: a meta‐analysis of reports on 79 crop and wild species. New Phytologist, 156(1), pp.9-26.

Jakobsen, I., Smith, S.E., Smith, F.A., Watts-Williams, S.J., Clausen, S.S. and Grønlund, M., 2016. Plant growth responses to elevated atmospheric CO2 are increased by phosphorus sufficiency but not by arbuscular mycorrhizas. Journal of experimental botany, 67(21), pp.6173-6186.

MetOffice, 2011. Climate: Observations, projections and impacts. United Kingdom [PDF]. Available online at http://www.metoffice.gov.uk/media/pdf/t/r/UK.pdf [Accessed 17th March 2017]

Mozell, M.R. and Thach, L., 2014. The impact of climate change on the global wine industry: Challenges & solutions. Wine Economics and Policy, 3(2), pp.81-89.



Plants – The Power of Adaptation in the Fight Against Climate Change

Posted on by Craig Turner
The adaptive power of plants could be crucial in sustaining the future of our planet! (Source: About Lifting)
The adaptive power of plants could be crucial in sustaining the future of our planet!
(Source: Aboutlifting.com)

 

From giant redwoods to small bonsai trees, all plants are bracing for a future of increasing global CO2 emissions.

FACT! In 2015, we as humans pumped out 36.3 GIGATONNES of CO2 into our atmosphere (GCP, 2016).

The Dilemma: Though rising atmospheric CO2 is almost always seen as a bad thing, the astute readers among you may ask: “isn’t that a good thing for plants, seeing as how they need CO2 to photosynthesise (convert CO2 gas into sugar for food)?”

The answer is a bit more complex than yes or no.

Studies have shown that in the short-term, increased CO2 concentrations:

  • Improve the efficiency of plant water use (Drake et al., 1997).
  • Increase the rates of photosynthesis (Drake et al. 1997).
  • Increase plant growth and productivity (Raschi et al., 1997).

 

… But.

Over longer timescales (days to weeks), the photosynthetic capabilities of plants can decrease because of a process called ACCLIMATISATION. To put it briefly, acclimatisation is when there is a build-up of leaf carbohydrates, such as sugars and starch, which triggers a decrease in the amount of RUBISCO enzyme (the enzyme responsible for upholding photosynthesis) in plants (Cheng et al., 1998).

Is the future all DOOM and GLOOM?

Encouragingly, the future looks somewhat optimistic…

A study using natural springs, which already emit high concentrations of CO2, found that over multiple generations, the “spring” plants that live there have become adapted to the elevated CO2 concentrations we can expect in the future, through the power of GENE EXPRESSION (Watson-Lazowski et al., 2016).

 

“Spring” and “non-spring” Plantago lanceolata plants from the Bossoleto natural spring in Italy. (Source: Herbalism)
“Spring” and “non-spring” Plantago lanceolata plants from the Bossoleto natural spring in Italy.
(Source: dspermaculture.wordpress.com)

 

Interestingly, the populations of “spring” and “non-spring/control” plants were genetically identical but over 800 genes were expressed differently between the two. Gene expression is kind of like a plug switch, genes can be turned on or off depending on the plant’s needs in order better suit its environment; it is thought that CO2 was directly regulating these changes in gene expression (Watson-Lazowski et al., 2016).

Differences in gene expression resulted in “spring” plants NOT BECOMING ACCLIMATISED to elevated CO2 conditions. In fact, the “spring” plants were able to photosynthetically fix carbon faster and produce larger carbon pools, they then used this additional carbon to enhance their growth through greater respiration (release of energy from carbon) (Watson-Lazowski et al., 2016).

Gene expression also caused the “spring” plants to increase their STOMATA (leaf pores used for gas exchange) index by 5.2% in elevated CO2 conditions, perhaps as an adaptive response (Watson-Lazowski et al., 2016). This contradicts previous studies that predict stomata numbers should have decreased.

What does this mean?

Well, it means that ability of plants to change their gene expression could be the underlying factor that enables future generations to adapt to rising atmospheric CO2. Questions as to whether this stark change in gene expression is capable in all plants and whether it is enough to enable them to fully adapt to future CO2 concentrations is yet to be tested; but this study shows that in the battle against climate change, plants may have a fighting chance!

References:

  1. CHENG, S. MOORE, B. & SEEMAN, J. (1998) Effects of short- and long-term elevated CO2 on the expression of ribulose-1,5-bisphosphate carboxylase/oxygenase genes and carbohydrate accumulation in leaves of Arabidopsis thaliana (L.) Heynh. American Society of Plant Physiologists. 116 (2). pp. 715-723.
  2. DRAKE, B. GONZALEZ-MELER, M. & LONG, S. (1997) More efficient plants: a consequence of rising atmospheric CO2. Annual Review of Plant Physiology & Plant Molecular Biology. 48. pp. 609-639.
  3. GLOBAL CARBON PROJECT, 2016. Global Carbon Budget. [pdf] Futurearth. Available at: http://www.globalcarbonproject.org/carbonbudget/16/files/GCP_CarbonBudget_2016.pdf.
  4. RASCHI, A. MIGLIETTA, F. TOGNETTI, R. & VAN GARDINGEN, P. (1997) Plant Responses to Elevated CO2: Evidence from Natural Springs. New York: Cambridge University Press.
  5. WATSON-LAZOWSKI, A. LIN, Y. MIGLIETTA, F. EDWARDS, R. CHAPMAN, M. & TAYLOR, G. (2016) Plant adaptation or acclimation to rising CO2? Insight from first multi-generational RNA-Seq transcriptome. Global Change Biology. 22 (11). pp. 3760 – 3773.

 

Word Count: 498

 



Plants in Elevated CO2: Stimulated Photosynthesis, Good News or Bad News?

Posted on by Jiahuan Gu

Climate change, I believe people are familiar with this word, although some of them may not believe it, it is the truth that is happening right now.

Since the Industrial Revolution, a large amount of CO2 has been released into the atmosphere due to the burning of fossil fuel. Human has obtained great development from Industrial Revolution and we are living a better life. However, the increasing concentration of CO2 in the atmosphere is warming our planet! We already know that the high temperature, extreme weather and sea level rise are the horrible consequences of climate change, but what about the impacts on plants?

Plants are the major terrestrial carbon sink. They absorb CO2 and water as raw materials, use sunlight as the energy source, release O2 and store sugars in organs as products, which support the plant growth and fix carbon in the wood and leaves. This process happens in the tiny chloroplast inside the cells of leaves and is called photosynthesis, which is a crucial chemical reaction on the earth, as oxygen is essential to human life.

The process of Photosynthesis

The process of Photosynthesis. (Patrickodonkor, 2017)

It seems that the increasing atmospheric concentration of CO2 provides the plants more CO2 input. Will it stimulate the photosynthesis process of plants? Probably. Some studies show that plants increase the photosynthesis rate in the elevated CO2 concentration, and especially, more evidence is found for the C3 plants (plants grow in the cool, wet climate) (Kirschbaum, 2004).

Although the plants may be happy with taking in more carbon for their growth and development, the Rubisco, which is the most abundant protein playing a role in the photosynthesis, seems unhappy with the elevated CO2. The activity of Rubisco decreases, and the Rubisco content shows a 20% drop in the elevated CO2 condition (Long et al., 2004). Such change is the acclimation of plants to the changing environmental condition, and the elevated CO2 decreases the photosynthesis capacity in long term.

However, even with the acclimation of photosynthesis capability, significant enhancement of carbon uptake has been found in the Free-Air Carbon dioxide Enrichment (FACE) studies of plants grow in the exposure to the CO2 concentration of estimated mid-century scenario (Leakey et al., 2009). This may be a good news, as the plants absorb more CO2, they can somewhat offset the greenhouse emissions and slow down the climate change. Moreover, the dry matter production and seed yield of C3 plants also slightly increased, although it is not as significant as the increase of carbon uptake (Long et al., 2004).

Another general finding of plant’s response to elevated CO2 is the increasing nitrogen use efficiency of photosynthesis. As the Rubisco decreases, less nitrogen is needed and the C: N ratio increases (Drake, Gonzàlez-Meler and Long, 1997). That is to say, the elevated CO2 reduce the nitrogen content in plant tissue and thus fewer nutrients are provided by the plants (Cotrufo, Ineson and Scott, 1998). People have to consume more food than before to obtain the same amount of nutrients!

Can you accept this trade off?

[493 words]

 

Reference

  • Cotrufo, M., Ineson, P. and Scott, A. (1998). Elevated CO2 reduces the nitrogen concentration of plant tissues. Global Change Biology, 4(1), pp.43-54.
  • Drake, B., Gonzàlez-Meler, M. and Long, S. (1997). MORE EFFICIENT PLANTS: A Consequence of Rising Atmospheric CO2?. Annual Review of Plant Physiology and Plant Molecular Biology, 48(1), pp.609-639.
  • Kirschbaum, M. (2004). Direct and Indirect Climate Change Effects on Photosynthesis and Transpiration. Plant Biology, 6(3), pp.242-253.
  • Leakey, A., Ainsworth, E., Bernacchi, C., Rogers, A., Long, S. and Ort, D. (2009). Elevated CO2 effects on plant carbon, nitrogen, and water relations: six important lessons from FACE. Journal of Experimental Botany, 60(10), pp.2859-2876.
  • Long, S., Ainsworth, E., Rogers, A. and Ort, D. (2004). RISING ATMOSPHERIC CARBON DIOXIDE: Plants FACE the Future. Annual Review of Plant Biology, 55(1), pp.591-628.
  • Patrickodonkor, (2017). Process of photosynthesis. [online] YouTube. Available at: https://www.youtube.com/watch?v=krat2mnM1M0 [Accessed 19 Mar. 2017].


It’s getting hot in here! Can plants handle global warming?

Posted on by Catherine Savage

Looking at the potential future impacts of climate change on global plant life                                     By Catherine Savage, University of Southampton student

The human race is turning over a new leaf – but not in a good way.

As we enter a new era, the Anthropocene, what will be the fate for plant life on earth?

plant
Source: Better globe AS, Copyright © 2017.

 

Everyone knows what climate change is, everyone knows that it is a current hot topic, but does everyone know what is happening to our plants because of it?

Global temperatures have risen 0.9 degrees throughout the last century (IPCC, 2013). This is predicted to rise by 4 degrees before 2100 (Thuiller, 2007).  A shocking reality to grasp, yet global temperature change is only one aspect encompassed in the concept of climate change.  What about changes in rainfall? Ice sheet melting? Sea level rise?

So, what are the underlying causes of climate change? Out of the greenhouse gases, carbon dioxide contributes the most to global warming at 65%. Current carbon dioxide concentration in the atmosphere is 387ppm, exceeding the safe level of 350ppm (Hansen et al., 2015). This has been heightened by fossil fuel burning and land-use change. The extra CO2 increases the greenhouse effect, resulting in trapped heat in the atmosphere which causes warming of the planet (Oktyabrskiy, 2016). For plants, this could either be a blessing or a curse. 

 

Plate 2. The world map showing projected daily temperatures in July by 2100, under predicted carbon dioxide levels of 935ppm (Gray, 2015).
Plate 1. The world map showing projected daily temperatures in July by 2100, under predicted carbon dioxide levels of 935ppm (Gray, 2015).

 

The good…

Climate change may be beneficial for plants:

  • Enhanced CO2 can increase the photosynthetic rate of plants, which could balance the effect of temperature increases (Thuiller, 2007).
  • With warmer soils, the decomposition rate of organic matter will increase, allowing plants a higher mineral and nutrient availability.
  • Growing seasons for crops may be extended and we could witness an improved agricultural productivity (Brown et al., 2016).

 

The bad…

However, it would be reckless to keep adding CO2 to the atmosphere. Too much of a good thing can be a bad thing right? Once you increase one substance, plants need to increase the rest too! Plants will be incapable of meeting these new requirements.

Changes in rainfall patterns and temperatures can further exacerbate abiotic stresses such as (Naithani, 2016):

  • Drought
  • Waterlogged soils
  • Saltwater inversion
  • Metal contamination

 

These impacts and more make it hard for plants to thrive, with the overarching impact of stunted growth (Worland, 2015).

Plate 2. The invasive Bromus tectorum, a species of the genum Bromus. It is known as the drooping brome or cheat grass.
Plate 2. The invasive Bromus tectorum, a species of the genum Bromus. It is known as the drooping brome or cheat grass. (Source: www.biology.csusb.edu)

Plus, non-native plant species may cross frontiers as conditions become more suitable, out-competing native plants (Thuiller, 2007; Smith et al., 2016; Walter et al., 2002).

The species of long grass, Bromus tectorum, has risen above native plant species in western North America due to being more suited to changes in the wet seasons (Smith et al., 2000).

The ugly…

The human race is a selfish species, perhaps the only way to kick people into action is to present the fact that no plants means no food. Crops won’t grow, land will become barren and food insecurity will explode (Worland, 2015). Could climate change wipe out homo sapiens as well as the worlds plants?

On a lighter note, the outlook may seem dire, but it is not too late for change. As the UN Secretary General Ban Ki-Moon quite rightly stated we are “the last generation that can end climate change”. We can protect and preserve our plants that will provide security to our future generations. Let’s all stop waiting for someone else to solve our problems, and be the change ourselves.

Word count: 499

 

References:

  • IPCC (2013) Climate change: the physical science basis. Working group contribution to the fifth assessment report of the intergovernmental panel on climate change. Cambridge University Press, Cambridge, UK and New York, USA.
  • Thuiller, W. (2007) Biodiversity: climate change and the ecologist.Nature,448(7153), pp.550-552.
  • Hansen, J., Sato, M., Ruedy, R., Lo, K., Lea, D.W. and Medina-Elizade, M. (2015) Global temperature change. Proceedings of the National Academy of Sciences, 103(39), pp.14288-14293.
  • Oktyabrskiy, V.P. (2016) A new opinion of the greenhouse effect.St. Petersburg Polytechnical University Journal: Physics and Mathematics,2(2), pp.124-126.
  • Brown, I., Thompson, D., Bardgett, R., Berry, P., Crute, I., Morison, J., Morecroft, M., Pinnegar, J., Reeder, T., and Topp, K. (2016) UK Climate Change Risk Assessment Evidence Report: Chapter 3, Natural Environment and Natural Assets. Report prepared for the Adaptation Sub-Committee of the Committee on Climate Change, London.
  • Gray, R. (2015) Our scorched Earth in 2100: Nasa maps reveal how climate change will cause temperatures to soar. [online] Available at: http://www.dailymail.co.uk/sciencetech/article-3125113/Earth-2100-Nasa-maps-reveal-world-need-adapt-rising-temperatures-caused-climate-change.html [Accessed 20 March 2017].
  • Naithani, S. (2016) Plants and global climate change: A need for sustainable agriculture. Current Plant Biology,6(2), p.1.
  • Worland, J. (2015) The weird effect climate change will have on plant growth. [Blog]Time. Available at: http://time.com/3916200/climate-change-plant-growth/ [Accessed 6 Mar. 2017].
  • Smith, S.D., Huxman, T.E., Zitzer, S.F., Charlet, T.N., Housman, D.C., Coleman, J.S., Fenstermaker, L.K., Seemann, J.R. and Nowak, R.S., (2000) Elevated CO2 increases productivity and invasive species success in an arid ecosystem.Nature,408(6808), pp.79-82.
  • Walther, G.R., Post, E., Convey, P., Menzel, A., Parmesan, C., Beebee, T.J., Fromentin, J.M., Hoegh-Guldberg, O. and Bairlein, F., (2002) Ecological responses to recent climate change.Nature,416(6879), pp.389-395.

 

Read more:

http://journal.frontiersin.org/article/10.3389/fpls.2016.01123/full 

http://www.open.edu/openlearncreate/mod/oucontent/view.php?id=22627&printable=1



Plants Revealed to be More Efficient at Higher CO2 Levels

Posted on by Erin Blandford

As we enjoy a varied diet of carbohydrates, proteins and fats, for plants it is the gas carbon dioxide (CO2), water and sunlight (figure. 1).

Figure. 1 Pedunculate Oak Tree; a temperate plant species that could be impacted by changing atmospheric conditions.
Figure. 1 Pedunculate Oak Tree in sunlight (Lind).

It is not just CO2 use which is made more efficient at elevated CO2 levels, water efficiency is greater as less water is lost from leaf pores; stomata. FACE (Free-Air CO2 Enrichment) experiments with soybean show that leaf pore conductance is not adapted to elevated CO2 but rather maintain decreased conductance. Furthermore, this increase in water efficiency is consistent between the leaf and canopy levels (Leakey et al, 2009).

 

It was also thought that higher CO2 levels lead to increased efficiency of nitrogen, a mineral required for growth, as plants grown at these levels do not have as much nitrogen present. These high CO2 grown plants also have a greater biological mass than those grown at normal CO2 conditions. However these CO2 levels where not found to affect levels of biological mass attained over plant lifetime which indicates that an accelerated period of growth that used up nitrogen reserves (Coleman et al, 1993). Increased CO2 levels are thought to contribute to increased uptake of nitrogen by plant roots rather than increased plant efficiency regarding nitrogen. Further FACE experiments at three separate forest locations showed that increased biological mass corresponded to increased nitrogen uptake from the soil. However this is limited to areas where nitrogen soil supply exceeds demand and is therefore unlikely to be seen in all plants worldwide (Finzi et al, 2007).

 

These FACE experiments are advantageous as they allow CO2 to be applied to a specific area of a wide range of ecosystems from desert to tropical forest. Trees as tall as 25m can be used in these experimental plots which can be as large as 30m in dimeter (Norby and Zak, 2011).

 

Figure.1 Atmospheric carbon dioxide (CO2) levels from 1950-2010 (IPCC, 2013)
Figure.2 Atmospheric carbon dioxide (CO2) levels from 1950-2010 (IPCC, 2013)

Scientists have been documenting rising atmospheric CO2, which is associated with planetary warming, for almost 70 years now, since 1950 (figure. 2). It is widely accepted that this change in CO2 has arisen from human industrialisation. While it seems that plants can positively cope with this change this conclusion must not be taken at face value and further studies must be undertaken.

 

 

 

  • Coleman, J.S., McConnaughay, K. D. M and Bazzaz, F. A. (1993). Elevated CO2 and Plant Nitrogen-Use: is reduced Tissue Nitrogen Concentration Size Dependent?. Oecologia. 93, 195-200.
  • Drake, B. G., Gonzalez-Meler, M. A and Long, S. P. (1997). More Efficient Plants: a Consequence of Rising Atmospheric CO2. Ann. Rev. Plant. Physiol. 48, 609-639.
  • Finzi, A. C., Norby, R. J., Calfapietra, C., Gallet-Budynek, A., Gielen, B., Holmes, W. E., Hoosbeek, M. R., Iversen, C. M, Jackson, R. B., Kubiske, M. E, Ledford, J., Liberloo, M., Oren, R., Polle, A., Pritchard, S., Zak, D. R., Schlesinger, W. H and Ceulemans, R. (2007). Increased in Nitrogen Uptake rather than Nitrogen-Use Efficiency support higher rates of Temperate Productivity under Elevated CO2. PNAS. 104 (35), 14014-14019.
  • IPCC, 2013: Summary for Policymakers. In: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S. K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.
  • Leakey, A. D. B., Ainsworth, E. A., Bernacchi, C. J., Rogers, A., Long, S.P and Ort, D. R. (2009). Elevated CO2 Effects on Plant Carbon, Nitrogen and Water Relations: six important lessions from FACE. Journal of Experimental Botany. 60 (10), 2859-2876.
  • Lind, J. © Photo of Pedunculate Oak Tree. Available: http://www.arkive.org/pedunculate-oak/quercus-robur/image-A20783.html. Last accessed 20th March 2017.
  • Norby, R. J and Zak, D. R. (2011). Ecological Lessons from Free-Air CO2 Enrichment (FACE) Experiments. Annual Review of Ecology, Evolution and Systematics. 42. 181-203.

[480 words]



Climate Change IS happening, and it’s set to starve the planet… (The opposite of FAKE NEWS!)

Posted on by Anonymous

With the large scale funding cuts of the Environmental Protection Agency in the USA, the current rapid rates of climate change and CO2 release show no hope of stopping.

But seeing as though plants breathe using CO2 (through the process of photosynthesis), and use carbon in their growth, surely the increased amounts of CO2 being pumped into our atmosphere is a good thing for plants?  As studies have shown; perhaps not…

Plants require very specific environmental conditions to function efficiently, and any changes in these conditions can be detrimental.  Although it has been shown that increased CO2 initially causes an increase in the rate of photosynthesis and growth of leaves and roots (Taylor et al 1994), generally, in the long-term, the stimulation of photosynthesis is actually suppressed!

This is mainly due to negative effects on the plants function, such as the build-up of excess starch (sugars) in leaves via increased photosynthesis, hindering breathing of CO2 via pores; called the stomata (Makino & Mae 1999), and increased CO2 also causes the stomata to partially close (Singh 2009), resulting in an inability to respire efficiently (Ryan 1991).

The mechanism for respiration in a plant leaf, through the stomata.
The mechanism for gas exchange in a plant leaf, through the stomata.  Source: Understanding Evolution

The failure to respire efficiently can cause the death of many food crops globally that are vital to feeding our populations!

Increased environmental CO2 also results in global warming due to increased reflection of the Sun’s radiation back to the Earth’s surface; and a temperature increase of 2-3⁰C over the next 30-50 years (IPCC 2007) is predicted to cause problems for our crops.  For example, warmer temperatures affect plants mainly when they are developing, and this has been shown to reduce the numbers of our food crop plants by 80%-90% (Hatfield & Prueger 2015), having dire consequences for our food supplies!

The global change in surface temperature from 1901-2012. A worrying trend that is set to worsen... Source: National Snow & Ice Data Center
The global change in surface temperature from 1901-2012. A worrying trend that is set to worsen… Source: National Snow & Ice Data Center

Climate change is also set to increase the frequency of extreme weather events (Rosenzweig et al 2001). With increased storms and flooding drowning plants in some areas, and in other areas increased drought, resulting in a lack of water for plants to function with, which they rely heavily on for processes such as photosynthesis, vital for growth and survival.  The equation for photosynthesis is shown below, in case you have forgotten…

 

The equation for photosynthesis, showing how carbon dioxide and water are transformed into oxygen and sugars through the light energy from the sun hitting the chlorophyll pigments in the plants cells.
The equation for photosynthesis, showing how carbon dioxide and water are transformed into oxygen and sugars through the light energy from the sun interacting with the chlorophyll pigments in the plants cells.

 

With increasing global temperatures, drought affected areas will increase from 15.4% to 44.0% by 2100 (Li et al 2009) – resulting in less land to grow crops, which will be disastrous for our food security, along with the fact that the number of suitable growing days per year for our crops will decrease by 11% by the year 2100 (Mora et al 2015)!

A sunny day on a Californian beach? Not exactly… This is Californian farmland suffering from a severe drought – completely unusable!
A sunny day on a Californian beach? Not exactly… This is Californian farmland suffering from a severe drought – completely unusable! Source:  New York Times

 

With the saying “Feed the World” becoming more and more poignant, our future looks bleak, as we are set to have less food security per person than ever before due to the detrimental effects that climate change will have on plant function. Also, plants not only provide food, but are also at the heart of our medicines and resources! So maybe Donald Trump ought to reconsider his views on climate change before threatening his new healthcare system before it has begun.

Word Count: 500

 

References:

Hatfield, J. and Prueger, J. (2015). Temperature extremes: Effect on plant growth and development. Weather and Climate Extremes, 10, pp.4-10.

IPCC, (2007). Climate Change 2007: Impacts, Adaptation and Vulnerability. New York: Cambridge University Press, p.17.

Li, Y., Ye, W., Wang, M. and Yan, X. (2009). Climate change and drought: a risk assessment of crop-yield impacts. Climate Research, 39, pp.31-46.

Makino, A. and Mae, T. (1999). Photosynthesis and Plant Growth at Elevated Levels of CO2. Plant and Cell Physiology, 40(10), pp.999-1006.

Mora, C., Caldwell, I., Caldwell, J., Fisher, M., Genco, B. and Running, S. (2015). Suitable Days for Plant Growth Disappear under Projected Climate Change: Potential Human and Biotic Vulnerability. PLOS Biology, 13(6), p.e1002167.

Rosenzweig, C., Iglesius, A., Yang, X., Epstein, P. and Chivian, E. (2001). Climate change and extreme weather events – Implications for food production, plant diseases, and pests. Global Change & Human Health, 2(2), pp.90-104.

Ryan, M. (1991). Effects of Climate Change on Plant Respiration. Ecological Applications, 1(2), pp.157-167.

Singh, S. (2009). Climate change and crops. 1st ed. Berlin: Springer, pp.5-6.

Taylor, G., Ranasinghe, S., Bosac, C., Gardner, S.D.L. and Ferris, R. (1994). Elevated CO2 and plant growth: cellular mechanisms and responses of whole plants. Journal of Experimental Botany, 45, pp.1761-1774.



Popeye didn’t cause the spinach shortage: why the effects of global environmental change on plant function is a double-edge sword

Posted on by Anonymous

Climate change – a myth? We have all heard of it and its impending threat to our global environment. However, what we should ask ourselves is how are plants affected by our planet’s increasing temperatures, carbon dioxide (CO2) levels and the increasing frequency and intensity of severe weather changes?

Diagram illustrating some factors mentioned that are linked to climate change and their impact on several biological processes carried out in plants
Diagram illustrating some factors mentioned that are linked to climate change and their impact on several biological processes carried out in plants (Source: (Kallarackal and Roby, 2012))

Plants play a critical role in pulling CO2 out of the atmosphere. This uptake of CO2 during photosynthesis is a major pathway by which carbon can be stored (Tkemaladze and Makhashvili, 2016). Carbon dioxide is predicted to increase to approximately 1000 ppm by 2100. Since the beginning of the Industrial Revolution approximately 200 years ago average global temperatures have increased by 0.85°C and by the end of the century temperature is projected to rise by approximately another 4°C (IPCC, 2013).  Some would assume this to be beneficial to plants due to these warmer temperatures and increased levels of gas as it should, in theory, encourage growth. However, it is not as straight forward as this.

The enzyme rubisco is the key to this photosynthetic process by fixing CO2. Drake et al. (1997) states that the increased levels of CO2 will allow greater fixation by plants and, therefore, result in increased growth. However, Bisgrove and Hadley (2002) found that long-term exposure to elevated levels of CO2 caused an accumulation of carbohydrates in plant tissues, which in turn reduced the rate of photosynthesis. Furthermore, although plants initially respond positively to increasing temperature, this will eventually plateau or even decline after reaching the optimum range for some species. Plants may experience an increased rate of respiration leading to death; illustrating the world’s plants can easily lose their ability to act as a global carbon sink, becoming instead yet another carbon source (Mellilo et al., 1990; Hawkins et al., 2008).

Moreover, another consequence of global environmental change is a change to global weather patterns. Many do not connect climate change with uncharacteristic weather events, however, there is no doubt that climate change affects their intensity and frequency. Thus, in the future, we can expect to experience more frequent periods of drought, floods and storms (Frich et al., 2002). For example, during the past winter, there was snow escape in Spain as we witnessed a window to our future in the form of the courgette and spinach crisis, which caused havoc and rationing in British supermarkets. Yet these changing weather patterns will have a much larger impact than just a blow to spiralizer sales.

 

The heavy snowfall the province of Murcia in Spain experienced this winter ruining many crops.
The province of Murcia in Spain experienced heavy snowfall this winter ruining many crops (Source:http://edition.cnn.com/2017/02/03/europe/lettuce-shortage-europe/)

Stated above are only a few effects global climate change has on our planet’s plants. Plants have an essential regulatory role in the control of our planet’s climate: they did yesterday, they do today and they most certainly will in the future. If we continue to allow the CO2 level to increase at the rate it is currently we will suffer dramatic consequences. It not only will affect the Earth’s vegetation such as forests and plants, but will also have a knock-on effect on global food production, therefore, affecting our wellbeing.

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References

Bisgrove, R. and Hadley, P. (2002). Gardening in the global greenhouse: The impacts of future landuse and climate on the red list status of the Proteaceae in the cape floristic region, South Africa. Global Change Biology, 69, pp.79-91.

Drake, B., Gonzàlez-Meler, M. and Long, S. (1997). More efficient plants: A Consequence of Rising Atmospheric CO2?. Annual Review of Plant Physiology and Plant Molecular Biology, 48(1), pp.609-639.

Frich, P., Alexander, L., Della-Marta, P., Gleason, B., Haylock, M., Klein Tank, A. and Peterson, T. (2002). Observed coherent changes in climatic extremes during the second half of the twentieth century. Climate Research, 19, pp.193-212.

Hawkins, B., Sharrock, S. and Havens, K. (2008). Plants and climate change; which future? Richmond, UK: Botanic Gardens Conservation International, pp.98.

IPCC (2013) Climate Change 2013: The Physical Science Basis.Intergovernmental Panel on Climate Change, Cambridge, UK.

Kallarackal, J. and Roby, T. (2012). Responses of trees to elevated carbon dioxide and climate change. Biodiversity and Conservation, 21, pp.1327-1342.

Melillo, J., Callaghan, T., Woodward, F., Salati, E. and Sinha, S. (1990). Effects on Ecosystems, in Climate Change: The IPCC Scientific Assessment, edited by J. Houghton, G. Jenkins, J. Ephraums, Cambridge University Press, Cambridge, pp.283−310.

Tkemaladze, G. and Makhashvili, K. (2016). Climate changes and photosynthesis. Annals of Agrarian Science, 14, pp.119-126.



Old Macdonald Overfarmed: How Increasing Global Agriculture leads to Deforestation

Posted on by Kieran Woof

The Rainforests are taking the hit from our need to eat…

Almost anyone could tell you that the world’s population is increasing – and rapidly so. Naturally, this requires us to produce more and more food with which to supply all of these new faces.

However, the constant expansion of farms leads to the constant decline of forest areas, which in turn causes detrimental effects on our environment as a whole. The main region affected by these practices is the Amazon Rainforest, well known for housing around half of all the species in the entire world, as well as acting as one of Earth’s biggest Carbon sinks.

This means that its destruction will lead to a huge reduction in biodiversity, as well as releasing vast amounts of trapped Carbon Dioxide into the atmosphere, which then contributes to Global Warming. As well as the pollution aspect, deforestation may also lead to the total extinction of many tree species. This may be caused by directly chopping these trees down, or by the reduction in animals which disperse the seeds, via eating the fruit they produce (Montoya, 2008).

Image result for rainforest deforestation for farming
Farmland is rapidly encroaching on our planets forested areas (Source: Emaze)

So how big is the problem?

It has been estimated that around 350 Million Hectares of Tropical Rainforest has been converted for other land use. (Lal, 2008) Furthermore, 91% of all land deforested in the Amazon since 1970 has been used for livestock pasture! (FAO, 2006). By Converting this land, not only are we losing trees in the long term, but we are also inhibiting their possible reintroduction. This is because the soil cleared for farming often rapidly degrades due to reduced stability and intense rainfall (Kibblewhite, 2008)

The problem here is that we cannot allow people to go without food in order to save our planet’s trees. What needs to change instead is the farming technique. In farm areas bordering rainforests, the method of farming is much more likely to be expansive rather than intensive (López-Carr, 2013). This essentially means that farmers focus on growing as much of the crop as possible, rather than trying to obtain more successful growth from a smaller patch. Essentially, this leads to a lot of land being wasted, with neither tropical forests or crops actually growing on it!

So what does the Future Hold?

However, there are reasons to be optimistic! A key success story in attempts to reduce deforestation, whilst keeping high crop production, is seen in the Soybean industry. This used to be seen as a major detrimental industry to the Amazon Rainforest. However, following boycotts from several large companies, a 2015 study showed that only around 1% of all soybean production had come as a result of deforestation, despite the industry expanding over 1.3 million hectares! (Garrett, 2016).

The Soybean – An unlikely success story (Source: Plant Village)

If this technique can be implemented for other farmland crops, then we can hopefully provide enough food to keep the growing population fed, as well as protecting one of the worlds most important ecological areas.

(Word Count – 485)

References

FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS . (2006). Livestock’s Long Shadow: Environmental issues and Problems.

Garrett, R, Rausch, L. (2016). Green for gold: social and ecological tradeoffs influencing the sustainability of the Brazilian soy industry. The Journal of Peasant Studies. 43 (2)

Kibblewhite, M.G, Ritz, K, Swift, M.J. (2008). Soil health in agricultural systems. Philosophical Transactions of the Royal Society B: Biological Sciences. 363 (1492), 685-701.

Lal, R. (2008). Carbon Sequestration. Philosophical Transactions of the Royal Society B: Biological Sciences. 363 (1492), 815-830.

López-Carr, D, Burgdorfer, J. (2013). Deforestation Drivers: Population, Migration, and Tropical Land Use. Environment. 55 (1)

Montoya, D. (2008). Habitat loss, dispersal, and the probability of extinction of tree species. Communicative and Integrative Biology. 1 (2), 146-147.



Bloom and Bust

Posted on by Lauren Furmidge
‘Blue Marble’ –Earth as seen by Apollo 17 (NASA/ Apollo 17 Crew, 1972)

 

In 1972, one of the most iconic photographs of the Earth was taken from space.  The ‘Blue Marble’ snapped by the astronauts aboard Apollo 17 shows an Earth with deep blue oceans but very little greenery on the land. Now photographs of the Earth from space look very different, with luscious green patches where there was once dull brown.  The spreading and growing of green vegetation is a result of rising CO2 levels in the Earth’s atmosphere.  The Earth has undergone an increase of 18 square kilometres of new vegetation between 1982 and 2009 (Keenan et al., 2016).

 

Since the Industrial Revolution, the burning of fossil fuels such as coal and oil by humans has caused an enormous rise in atmospheric CO2 from 280ppm to over 400ppm today, inducing disastrous effects on the environment such as climate change (Khatiwala et al., 2009).

So if increases in CO2 are so bad, why is a boom in plant growth occurring?

 

Plants use CO2 in photosynthesis; a process in which plants use CO2, water and light from the sun to produce sugars for growth and oxygen which they give off.  The increased rates of photosynthesis are down to a chemical called Rubisco, which helps incorporate CO2 into the photosynthesis process.  Rubisco first evolved long, long ago- far before humans began affecting the world.  At this point in history CO2 levels were much greater than during recent times.  This means that Rubisco is less efficient at lower CO2 levels.  As humans have begun to disturb these lower CO2 concentrations and caused them to rise, Rubisco works better meaning plants are able to photosynthesise at a greater rate, which increases their growth (Taylor et al., 1994).

 

Sun through leaves (Shuttershock, 2013)
Sun through leaves (Shuttershock, 2013)

 

Although this appears to be all good news for the plants, rising atmospheric CO2 levels also bring negative effects, one of them being climate change.  With increasing CO2 comes increases in temperature which can negatively impact plants.  Plants require an optimum temperature in order to survive well and if they are not able to shift their ranges, they will suffer the effects of warmer, dryer environments which are ultimately inhospitable (Hatfield and Prueger, 2015).  So whilst plants prosper in the short term, when temperatures get too high they languish.

Also, there is evidence that rising CO2 reduces the ability of stomata- small pores on plants- to conduct CO2 and perform transpiration- the removal of water-, ultimately leading to reduced photosynthesis (Drake et al., 1997).

 

Although rising CO2 has turned the brown swathes of Earth captured in the ‘Blue Marble’ into luscious green, behind this initial bloom lurks an ominous truth. If humans continue to fuel rising CO2 levels, plants will suffer and food crops will fail. Global temperature increases, rainfall changes and extreme weather events- droughts and floods- jeopardise the functions of plants, ultimately devastating them.

 

Word Count: 468

 

 

References

Drake, B.G., Gonzalez-Meler, M.A., Long, S.P.,1997. More efficient plants: a consequence of rising atmospheric CO? Annu. Rev. Plant Physiol. Plant Mol. Biol. 48, 609 – 639.

Hatfield, J.L. and Prueger, J.H., 2015. Temperature extremes: effect on plant growth and development. Weather and Climate Extremes, 10, pp.4-10.

Keenan, T.F., Prentice, I.C., Canadell, J.G., Williams, C.A., Wang, H., Raupach, M. and Collatz, G.J., 2016. Recent pause in the growth rate of atmospheric CO2 due to enhanced terrestrial carbon uptake. Nature communications, 7.

Khatiwala, S., Primeau, F. and Hall, T., 2009. Reconstruction of the history of anthropogenic CO2 concentrations in the ocean. Nature, 462(7271), pp.346-349.

NASA/ Apollo 17 Crew., 1972., ‘Blue Marble’ –Earth as seen by Apollo 17. [Photograph]

Shuttershock., 2013., Sun through leaves. [Photograph]

Taylor, G., Ranasinghe, S., Bosac, C., Gardner, S.D.L. and Ferris, R., 1994. Elevated CO2 and plant growth: cellular mechanisms and responses of whole plants. Journal of Experimental Botany, 45(Special Issue), pp.1761-1774.