The University of Southampton

Changes to Plant Flowering Times – Forgettable or Regrettable?

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)




Stomata – an ancient insight into a modern problem

Findings from a pharaoh

What can an Egyptian pharaoh from 1300 BC tell us about how plants will respond to 21st century environmental change?

Olive leaves in Tutankhamun’s tomb allowed Beerling & Chaloner to show that the number of stomata declined in response to increasing CO2. Photo credit – Discovery Times Square Museum (Available: http://www.discoverytsx.com/exhibitions/kingtut).
Olive leaves in Tutankhamun’s tomb allowed Beerling & Chaloner to show that the number of stomata declines in response to increasing levels of carbon dioxide.
Photo credit – Discovery Times Square Museum (Available: http://www.discoverytsx.com/exhibitions/kingtut).

 

When Howard Carter discovered King Tutankhamun’s tomb in 1922, the boy pharaoh’s treasures captivated the world. Amidst such splendor, olive leaves found in the burial chamber were overlooked. But, in 1993, two botanists, David Beerling and William Chaloner decided to compare these leaves with their modern counterparts. They found that olive leaves grown today have 33% fewer stomata (tiny ‘pores’ on the leaf surface) than they did in 1300 BC. Beerling & Chaloner linked this decline in stomata to increasing carbon dioxide (CO2) levels.

Stomata – microscopic pores on the surface of a leaf let plants ‘breathe’.
Photo credit – University of California Museum of Paleontology’s Understanding Evolution (http://evolution.berkeley.edu).

 

Powerful pores

Stomata (singular – stoma) are vital to plant function. Plants use these pores to ‘breathe’. Stomata allow CO2 to enter a leaf, where it is used in photosynthesis to generate sugars, which the plant needs to survive and grow. The trade-off is stomata also let water escape. Plants, therefore, need to balance CO2 gain and water loss.

Stomata control a vital trade-off between carbon dioxide gain and water loss.
Photo credit – University of California Museum of Paleontology’s Understanding Evolution (http://evolution.berkeley.edu).

 

Rising CO2 – a certainty in an uncertain world

CO2 is the most well known of the greenhouse gases. These gases trap the Sun’s heat within Earth’s atmosphere, causing our planet to warm up. We produce CO2 every day when we burn oil, gas and coal to drive our cars, heat our homes and power our factories.

This has caused CO2 levels to increase by 40% since the industrial revolution started in 1750 (IPCC, 2014). CO2 levels are predicted to increase more rapidly in the future as populations and economies grow (IPCC, 2014).

With some exceptions (Bettarini et al., 1998), most scientists agree that this rise in CO2 will cause a decline in stomatal density (Woodward & Kelly, 1995; Lin et al., 2001). Paoletti et al. (1998) showed that stomata numbers will decline until CO2 levels reach 750 μmol mol-1.

But, how will this change impact plant function?

Some plants naturally have few stomata because they have a change in the gene that controls stomatal development (Gray et al., 2000). As CO2 levels rise, each stoma will be able to bring in more CO2. So, a leaf will need fewer stomata to bring in the same amount of CO2.

A leaf with fewer stomata will lose less water. As a result, the plant will have a higher water use efficiency and so has an advantage over others (Drake et al., 1997). With time, CO2 will act as a selection pressure and these plants will become more common.

Stomatal density will decline as CO2 levels rise. Photo credit - University of California Museum of Paleontology's Understanding Evolution (http://evolution.berkeley.edu).
Stomatal density will decline as carbon dioxide levels rise.
Photo credit – University of California Museum of Paleontology’s Understanding Evolution (http://evolution.berkeley.edu).

 

Future plants will be better able to conserve water, making them more tolerant to periods of water stress (Woodward, 1987). This is just as well as droughts are predicted to become more common (IPCC, 2014). It will also mean we will be able to grow the same amount of crops, but using less water (Drake et al., 1997).

Stomata transfer water from the land to the atmosphere. If plants have fewer stomata, less water will be transferred, which will cause increased air temperatures and runoff (Kürschner et al., 1997).

The olive leaves from King Tut’s tomb showed that stomata respond to CO2 levels. With rises in CO2 predicted for the 21st century, perhaps the insights provided by these leaves are the boy pharaoh’s most valuable treasure.

 

References

Beerling, D.J. & Chaloner, W.G. (1993) Stomatal density responses of Egyptian Olea europaea L. leaves to CO2 change since 1327 BC. Annals of Botany. 71(5), 431-435.

Bettarini, I., Vaccari, F.P. & Miglietta, F. (1998) Elevated CO2 concentrations and stomatal density: observations from 17 plant species growing in a CO2 spring in central Italy. Global Change Biology. 4(1), 17-22.

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

Gray, J.E., Holroyd, G.H., Van Der Lee, F.M., Bahrami, A.R., Sijmons, P.C., Woodward, F.I., Schuch, W. & Hetherington, A.M. (2000) The HIC signalling pathway links CO2 perception to stomatal development. Nature. 408(6813), 713-716.

IPCC (2014) Summary for Policymakers. In: Pachauri. R.K. & Meyer, L.A. (eds.) Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. IPCC, Geneva, Switzerland, pp. 1-31.

Kürschner, W.M., Wagner, F., Visscher, E.H. & Visscher, H. (1997) Predicting the response of leaf stomatal frequency to a future CO2-enriched atmosphere: constraints from historical observations. Geologische Rundschau. 86(2), 512-517.

Lin, J., Jach, M.E. & Ceulemans, R. (2001) Stomatal density and needle anatomy of Scots pine (Pinus sylvestris) are affected by elevated CO2. New Phytologist. 150(3), 665-674.

Paoletti, E., Nourrisson, G., Garrec, J.P. & Raschi, A. (1998) Modifications of the leaf surface structures of Quercus ilex L. in open, naturally CO2-enriched environments. Plant, Cell & Environment. 21(10), 1071-1075.

Woodward, F.I. & Kelly, C.K. (1995) The influence of CO2 concentration on stomatal density. New Phytologist. 131(3), 311-327.

Woodward, F.I. (1987) Stomatal numbers are sensitive to increases in CO2 from pre-industrial levels. Nature. 327(6123), 617-618.

 

Word count: 499





The Grass isn’t always Greener on the other side

Photo credit https://loristillman.files.wordpress.com/2013/04/screen-shot-2013-04-30-at-6-07-14-am.png?w=764
Photo credit https://loristillman.files.wordpress.com/2013/04/screen-shot-2013-04-30-at-6-07-14-am.png?w=764

Despite what certain orange men in white buildings may say. It is an inconvenient truth that Global Climate Change is occurring (Kerr, 2001) and may in fact not be a lie created by the Chinese.

What is more up for debate however, is exactly what is going to happen to the earth over the next hundred years. Among many problems better left unsaid, a concept has emerged that global climate change may lead to increased growth rates amongst plants (Nemani, 2003).

As a result of the inputs of additional carbon dioxide into the atmosphere from man-made sources, photosynthesis rates have increased; which has ultimately led to increased plant growth. On the surface of things this may sound like a good result, however below the surface i.e under the sea; this can have entirely different implications.

The increase of carbon dioxide levels in the atmosphere has also led to an increasing global temperature as well as an increasing ocean temperature (Hansen et al,. 2006). Many underwater plants may be detrimentally affected by this including the vast meadows of seagrass which support many of our favourite undersea critters such as the manatee.

A manatee swimming, blissfully unaware of all life’s problems that may await him. Photo credit: https://www.fws.gov/caribbean/images/Moises_by_Alejandro_Avampini.jpg
A manatee swimming, blissfully unaware of all life’s problems that may await him. Photo credit: https://www.fws.gov/caribbean/images/Moises_by_Alejandro_Avampini.jpg

Most organisms on this planet can only live within a certain range of temperatures and when plants or animals are pushed beyond this range they can struggle to survive.

(No prizes for guessing what this means?)

Warming associated with climate change is causing many animals and plants to move beyond their comfortable ranges (Walther et al,. 2002). This is true for many species of temperate seagrasses which are struggling with rising temperatures (Short and neckless, 1999). Increasing temperatures are pushing them out of their desired temperature range of between the lower end of 21 and 32 °C; causing them to a enter a thermal stress. This facilitates a breakdown of a crucial step in photosynthesis known as ‘photosystem II’ (Koch et al,. 2012) and prevents them from photosynthesizing properly.

To make matters worse, other more tropical species of seagrass may begin to move in to temperate seagrasses habitats, as the warmer temperatures allow them to occupy and outcompete them for space. This is because as opposed to temperate species, warmer temperatures of around 27 – 33 °C tend to increase the photosynthetic rates of tropical species (Koch et al,. 2012).

A beautiful seagrass meadow, blissfully unaware of all life’s problems that await it. Photo credit: http://www.stevedeneef.com/index/G00000uAGDq2A_UQ/thumbs
A beautiful seagrass meadow, blissfully unaware of all life’s problems that await it. Photo credit: http://www.stevedeneef.com/index/G00000uAGDq2A_UQ/thumbs

But like all things in life the tropical seagrass species can’t have it all. As in their native tropical environments some species are far more susceptible to temperature changes and subsequent increases will cause a breakdown of photosystem II, which leads to heat-induced photoinhibition (Campbell, McKenzie and Kerville, 2006). This subsequently means its ability to photosynthesize is reduced.

In closing it appears that many of the undersea grasses found globally, that are so crucial to many species on earth are going to be negatively affected by global climate change. And if nothing is done to stop it, we could be saying goodbye to a truly beautiful part of nature.

Word count – 489

 

References

Campbell, S., McKenzie, L. and Kerville, S. (2006). Photosynthetic responses of seven tropical seagrasses to elevated seawater temperature. Journal of Experimental Marine Biology and Ecology, 330(2), pp.455-468.

Hansen, J., Sato, M., Ruedy, R., Lo, K., Lea, D. and Medina-Elizade, M. (2006). Global temperature change. Proceedings of the National Academy of Sciences, 103(39), pp.14288-14293.

Kerr, R. (2001). GLOBAL WARMING: Rising Global Temperature, Rising Uncertainty. Science, 292(5515), pp.192-194.

Koch, M., Bowes, G., Ross, C. and Zhang, X. (2012). Climate change and ocean acidification effects on seagrasses and marine macroalgae. Global Change Biology, 19(1), pp.103-132.

Nemani, R. (2003). Climate-Driven Increases in Global Terrestrial Net Primary Production from 1982 to 1999. Science, 300(5625), pp.1560-1563.

Short, F. and Neckles, H. (1999). The effects of global climate change on seagrasses. Aquatic Botany, 63(3-4), pp.169-196.

Walther, G., Post, E., Convey, P., Menzel, A., Parmesan, C., Beebee, T., Fromentin, J., Hoegh-Guldberg, O. and Bairlein, F. (2002). Ecological responses to recent climate change. Nature, 416(6879), pp.389-395.

Photo credits

Loristillman, (2017). The Grass is Green Where You Water It. [online] Loristillman.files.wordpress.com. Available at: https://loristillman.files.wordpress.com/2013/04/screen-shot-2013-04-30-at-6-07-14-am.png?w=764 [Accessed 19 Mar. 2017].

Steve De neef, (2017). Steve De Neef Photography. [online] Stevedeneef.com. Available at: http://www.stevedeneef.com/index/G00000uAGDq2A_UQ/thumbs [Accessed 20 Mar. 2017].

US Fish and Wildlife Service, (2017). Antillean Manatee Fact Sheet. [online] Fws.gov. Available at: https://www.fws.gov/caribbean/images/Moises_by_Alejandro_Avampini.jpg [Accessed 20 Mar. 2017].

 





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

 

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 Agronomy14(2), pp.145-155.

Craufurd, P.Q. and Wheeler, T.R., 2009. Climate change and the flowering time of annual crops. Journal of Experimental Botany60(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 biology48(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 Sciences110(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 Phytologist156(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 botany67(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 Policy3(2), pp.81-89.





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

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 COon 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

 





Walking on thin ice – Why we should care about the polar bear

solo-bear

I’m sure you’ve all seen enough TV adverts showing polar bears floating on small patches of ice by now to just roll your eyes and change channel. I’m also sure you’ve thought to yourself “Why is it always polar bears?” and “Why should I care?”. I’d like to explain why polar bears and, more broadly, arctic ice are so important and why, instead of averting our eyes, we should be paying more attention than ever.

Most scientists agree that polar bears are in serious trouble. With their habitat and hunting ground of choice, arctic sea ice, disappearing at a rate of 13 percent per year (Nsidc.org, 2017) polar bears are getting thinner (Obbard et al., 2016) and those cute baby polar bears are bearing the brunt of it (Pagano et al., 2012). Polar bears use the ice as platforms to catch their main source of food, ringed and harp seals, with a surprising amount of stealth and guile for 2.5m long, 700 kilo apex predators.

Derek never saw it coming.
Derek never saw it coming.

With longer swims required to reach the ice each year, fewer polar bear cubs can make the swim (Pagano et al., 2012 and Hassol, 2004). No more cubs mean no more polar bears. No more polar bears would have enormous knock-on effects on the artic ecosystem. For example, if harp seal numbers were to increase due to lack of predation, numbers of Northern shrimp would drop significantly (Hassol, 2004). Northern shrimp have no fewer than 16 predators and so act as a lynchpin for a significant portion of the food web (Parsons, 2005).

With a 0.48°C increase in global temperatures between 1984 and 2012, Winter ice cover in the arctic saw an almost 50% decrease. Check out this GIF from NASA for a better idea: http://photojournal.jpl.nasa.gov/archive/PIA14385.gif
With a 0.48°C increase in global temperatures between 1984 and 2012, Winter ice cover in the arctic saw an almost 50% decrease. Check out this GIF from NASA for a better idea: http://photojournal.jpl.nasa.gov/archive/PIA14385.gif

Why does this matter then? More than anything, the plight of the polar bear represents our success or failure in safeguarding our planet. Breaking apart the food web of the arctic doesn’t just affect the ecosystem there; If we continue the path we are currently on, then we risk damaging the ecosystem to the point where we lose out on 7 million tons of fish every year (Hassol, 2004 and EPA, 2017).

fishing-graph

It’s no coincidence that the loss of sea ice (B) is directly correlated with a drop in Northern shrimp (A) (Pandalus borealis). Cod can migrate to other areas of ice with more ease than shrimp so can maintain reasonable numbers for the time being.
It’s no coincidence that the loss of sea ice (B) is directly correlated with a drop in Northern shrimp (A) (Pandalus borealis). Cod can migrate to other areas of ice with more ease than shrimp so can maintain reasonable numbers for the time being.

Damage to the arctic ecosystem doesn’t stop at polar bears and fish. The effects of arctic ice reduction will be felt all over the globe from rising sea levels to the loss of cold-adapted species, such as the humble lemming. With enough warming, those cold-adapted species will struggle to survive while other invasive species will suddenly have massive stretches of land made available to them (Ware, 2013). The most serious problem, however, is that we may have set off a chain of events that is running far out of our control.

If left unchecked this feedback loop will be disastrous for humanity, with more frequency storms, more forest fires and some regions could even turn into new deserts.
If left unchecked this feedback loop will be disastrous for humanity, with more frequency storms, more forest fires and some regions could even turn into new deserts.

It isn’t all doom and gloom of course, its predicted that we’ll see more trans-arctic marine transport and (unfortunately) better access to arctic oil deposits which will help off-set the damage (Hassol, 2004 and Block, 2016). The question we need to ask ourselves, however, is “Will it be worth it?

A protest from Sierra club, a group of environmental activists, attempting to stop a mid-2000s arctic oil drilling project named “Liberty project” from Hilcorp.
A protest from Sierra club, a group of environmental activists, attempting to stop a mid-2000s arctic oil drilling project named “Liberty project” from Hilcorp.

Word count: 485

References:

  • Nsidc.org. (2017). Arctic Sea Ice News and Analysis | Sea ice data updated daily with one-day lag. [online] Available at: http://nsidc.org/arcticseaicenews/ [Accessed 20 Mar. 2017].
  • Obbard, M., Cattet, M., Howe, E., Middel, K., Newton, E., Kolenosky, G., Abraham, K. and Greenwood, C. (2016). Trends in body condition in polar bears ( Ursus maritimus ) from the Southern Hudson Bay subpopulation in relation to changes in sea ice. Arctic Science, 2(1), pp.15-32.
  • Pagano, A., Durner, G., Amstrup, S., Simac, K. and York, G. (2012). Long-distance swimming by polar bears ( Ursus maritimus ) of the southern Beaufort Sea during years of extensive open water. Canadian Journal of Zoology, 90(5), pp.663-676.
  • Hassol, S. (2004). Impacts of a warming Arctic. 1st ed. [ebook] Cambridge: Cambridge University Press. Available at: http://www.cambridge.org/gb/academic/subjects/earth-and-environmental-science/climatology-and-climate-change/impacts-warming-arctic-arctic-climate-impact-assessment?format=PB&isbn=9780521617789 [Accessed 20 Mar. 2017].
  • Parsons, D. (2005). Predators of northern shrimp,Pandalus borealis(Pandalidae), throughout the North Atlantic. Marine Biology Research, 1(1), pp.48-58.
  • gov. (2017). Climate Impacts on Ecosystems | Climate Change Impacts | US EPA. [online] Available at: https://www.epa.gov/climate-impacts/climate-impacts-ecosystems [Accessed 20 Mar. 2017].
  • Ware, C. (2013). Arctic at risk from invasive species. [Blog] The Ecologist. Available at: http://www.theecologist.org/News/news_analysis/2173097/arctic_at_risk_from_invasive_species.html [Accessed 20 Mar. 2017].
  • Block, B. (2016). Arctic Melting May Lead To Expanded Oil Drilling | Worldwatch Institute. [online] Worldwatch.org. Available at: http://www.worldwatch.org/node/5664 [Accessed 20 Mar. 2017].

 

Figures:

Figure 1 – Polar bear on ice – Available from: http://www.endangeredpolarbear.com/uploads/1/4/2/4/14243313/2894929.png

Figure 2 – Polar bear hunting seal – Available from: https://i.ytimg.com/vi/MC26JK9nk-8/maxresdefault.jpg

Figure 3 – Arctic ice loss from 1984-2012 – Available from: https://intellihub.com/wp-content/uploads/2015/01/1348775537_2624_composite.jpg

Figure 4A – Past and predicted fishing – Available from Reference number 3.

Figure 4B – Arctic sea ice loss graph – Available from: http://nsidc.org/images/arcticseaicenews/20101004_Figure3.png

Figure 5 – Arctic warming positive feedback loop – Available from: http://www.climateemergencyinstitute.com/uploads/arctic_fb1.png

Figure 6 – The Arctic is not for sale – Available from: http://www.k-zap.org/wp-content/uploads/2015/12/arctic-drilling.jpg





Turmoil in the Tundra: the Cold Hard Truth

A harsh, cold land with no tree cover, temperatures averaging between -12 to -6 degrees Celsius, and enveloped in snow for the majority of the year (National Geographic, 2017).

Until the brief summer months bring warmth and plains become decorated with swathes of wildflowers. This is the tundra biome.

 

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                                        Figure 1: Arctic animals

 

A home to many endearing (and endangered) animals like the Arctic fox, snowy owl, lemmings and grey-wolves (Figure 1) (National Geographic, 2017). But why should we care about some cold desolate place? The answer is simple yet complicated.

It comes down to the ever looming climate change disaster. The Arctic tundra has been recognised as one of the most vulnerable biomes to environmental change. Permafrost (permanently frozen ground) covers much of the tundra, with the top 30cm or so of it melting and refreezing with the changing seasons (NOAA, 2017). However, in the last few decades increasing global temperatures, and human developments have lead to more melting. This can have a negative effect on the ecosystem as the more permafrost that’s melted, along with the later arrival of the autumn freeze time means that shrubs and other vegetation, that couldn’t take root before, can now grow, potentially altering the habitat (Heijmans et al 2016).

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Figure 2. Different types of interactions within an Arctic tundra ecosystem. Solid lines = consumption between predator and prey between trophic levels (different parts of the food web Dotted lines = interaction between species in the same trophic level (same part of the food web) (Ims and Fuglei, 2005).

 

Northward expansion of Low Arctic trees and shrubs has been seen due to the warmer temperatures and longer growing seasons. This has other ecological consequences, like change in the biodiversity of an area if new species are introduced (Post et al., 2009). Overall ecosystem structure change has been recorded in multiple studies, including interaction between animal species (Hobbie et al 2017).

Although they may be cute and fluffy Arctic foxes are one of the key species within Arctic tundra ecosystems because they are a top predator, meaning they help control herbivore populations (Figure 2). It’s been seen that where abandoned Arctic fox dens are found, the productivity of that area (i.e. plant growth, number of insect and herbivores etc.) has increased (Killengreen et al., 2007).

A study by Ims and Fuglei, (2005) has shown that lemmings are also key players in the Arctic tundra. These rodents are a key prey species for a number of predators that rely on certain densities of lemming populations to allow them to reproduce, as they need sufficient amount of food. Lemmings breed during the winter season and undergo growth under the snow, leading to a peak in population density in spring. This means that with predicted warmer winters (hence less snow, and more rain) lemming peak times are very likely to alter, with population peaks happening during autumn (Putkonen and Roe, 2003). A change in the number of prey available, will impact predator numbers. Arctic fox and snowy owl numbers are likely to decrease as they will have lower reproductive rates during years when peak lemming populations occur autumn.

A change in the relationships between key species like this can have unprecedented effects on their communities and ecosystems. With a grim future ahead for cold-loving animals and ecosystems.

 

 

References

National Geographic, (2017). Explore the World’s Tundra. Available at: http://www.nationalgeographic.com/environment/habitats/tundra-biome/ [Accessed 17 Mar. 2017].

NOAA (2017). Arctic Change – Land: Permafrost. Available at: https://www.pmel.noaa.gov/arctic-zone/detect/land-permafrost.shtml [Accessed 17 Mar. 2017].

Post, E., Forchhammer, M. C., Bret-Harte, M. S., Callaghan, T. V., Christensen, T. R., Elberling, B., … & Ims, R. A. (2009). Ecological dynamics across the Arctic associated with recent climate change. Science, 325(5946), 1355-1358.

Ims, R. A., & Fuglei, E. V. A. (2005). Trophic interaction cycles in tundra ecosystems and the impact of climate change. Bioscience, 55(4), 311-322.

Killengreen, S. T., Ims, R. A., Yoccoz, N. G., Bråthen, K. A., Henden, J. A., & Schott, T. (2007). Structural characteristics of a low Arctic tundra ecosystem and the retreat of the Arctic fox. Biological Conservation, 135(4), 459-472.

Putkonen J, Roe G. 2003. Rain-on-snow events impact soil temperatures and affect ungulate survival. Geophysical Research Letters 30: 1188.

Heijmans, M. M. P. D., van Huissteden, J., Li, B., Wang, P., Limpens, J., Berendse, F., & Maximov, T. C. (2016). Can wet summers trigger permafrost collapse at a Siberian lowland tundra site?. INTERNATIONAL CONFERENCE ON PERMAFROST, 2016-06-20/2016-06-24

Hobbie, J. E., Shaver, G. R., Rastetter, E. B., Cherry, J. E., Goetz, S. J., Guay, K. C., … & Kling, G. W. (2017). Ecosystem responses to climate change at a Low Arctic and a High Arctic long-term research site. Ambio, 46(1), 160-173.

 

Word count [496]

 

 

 





King Louie’s Last Stand: Are we set to lose Southeast Asia’s jungle kingdoms?

With his charm, charisma and infectious enthusiasm for big band jazz, it was the Jungle Book’s King Louie who first introduced many of us to the rainforests of Southeast Asia. But beyond now sounding an awful lot like Christopher Walken, what’s happened to the old Orang-utan over the last 50 years?

Unfortunately, there’s little to report in the way of good news. Despite our affections, Orang-utans, along with much of their rainforest ecosystem, are struggling to survive. Mowgli, as it turns out, grew up…and in doing so, discovered that selling oil derived from palm nuts is a quick and easy means of turning a profit (McCarthy et al., 2012).

orang-utan
Times are tough for Orang-utans. Image credit: YeeChao, Koh via Flickr

As a result, the production of palm oil has become big business throughout the developing world, but particularly in Southeast Asia (Koh and Wilcove, 2007). The implications for rainforest ecosystems however, are dire. In order to produce palm oil, vast areas of rainforest must be cleared to make way for plantations of oil palms.

Such a widespread loss of habitat poses an obvious threat to iconic species such as the Orang-utan who depend on the rainforest for survival. However, the problem of palm oil may run deeper.

sun-bear
It’s not just Orang-utans that are endangered by land use change. Deforestation has likely contributed to a 30% decline (Fredriksson et al., 2008) in the population of Sun Bears and resulting human conflict is well documented (Wong, et al., 2015).  Image credit: skepticalview via Flickr
The region’s famous Black Panthers (left), or rather, melanistic Indochinese Leopards (AKA, Bagheera (right)), are struggling, having lost 93% of their Asian habitat (Hance, 2016).  Image credit: (left) Tambako via Flickr, (right) Disney
The region’s famous melanistic Leopards (left), AKA Bagheera (right), are also struggling, having lost 93% of their Asian habitat (Hance, 2016).
 Image credit: (left) Tambako via Flickr, (right) Disney

The emerging field of complexity science suggests additional concerns in that we should consider also the nature of deforestation patterns and the effect this has on the capacity of rainforests to recover from stress. Only then, can we hope to effectively conserve rainforest ecosystems.

Unsurprisingly, deforestation occurs largely along the fringes of roads. However, this results in not only habitat loss, but also habitat fragmentation. In isolating patches of rainforest within traffic laden road networks, organisms become trapped. Reducing the connectivity of an ecosystem in this way can in turn undermine its resilience (Pardini et al., 2010); that is, its ability to respond and recover from stress events.

For example, if a fire were to break out in an isolated forest surrounded by roads, mammal species may find it difficult to escape and would therefore perish. Furthermore, without the movement of organisms to transport seeds, some plant species could encounter difficulty recolonising the area once the flames have subsided.

It is worth noting that the barriers between isolated rainforest stands expand from busy roads to entire palm oil plantations spanning hundreds of square kilometres. When we consider that the plantations themselves can form barriers to even some bird species (Knowlton et al., 2017), the need for an urgent and effective solution becomes clear.

Indonesia, 2007.
Approximately 45% of the palm oil plantations in Southeast Asia were pristine rainforest in 1989 (Vijay et al., 2016). Image credit: CIFOR via Flickr

Alongside traditional restoration methods, the development of forest corridors may provide the answer (Sodhi et al., 2010), with similar projects having achieved success elsewhere in the world (Wyborn, 2011). In providing a means for organisms to travel between detached rainforest patches, ecosystem managers can enhance the resilience of the habitat and help to ensure its continued survival.

However, effective implementation must be swift. Else we run the risk of losing King Louie and his jungle kingdom, forever.

Click here more info on how ecosystems can be managed to improve their resilience.

Can King Louie be saved? Image credit: CIFOR via Flickr
Can King Louie be saved?
Image credit: CIFOR via Flickr

Word count: 500

References:

Fredriksson, G., Steinmetz, R., Wong, S. and Garshelis, D.L. (IUCN SSC Bear Specialist Group) (2008) Helarctos malayanus. The IUCN Red List of Threatened Species 2008. Available from: http://dx.doi.org/10.2305/IUCN.UK.2008.RLTS.T9760A13014055.en. [Accessed 14 March 2017].

Hance, J. (2016) Another big predator in Southeast Asia faces extinction. The Guardian, 31 August. Available from: https://www.theguardian.com/environment/radical-conservation/2016/aug/31/leopards-tigers-asia-snares-poaching-endangered-extinction [Accessed 14 March 2017].

Knowlton, J.L., Phifer, C.C., Cerqueira, P.V., Barro, F.D.C., Oliveira, S.L., Fiser, C.M., Becker, N.M., Cardoso, M.R., Flaspohler, D.J. and Dantas Santos, M.P. (2017) Oil palm plantations affect movement behavior of a key member of mixed-species flocks of forest birds in Amazonia, Brazil.Tropical Conservation Science, 10, 1-10.

Koh, L.P. and Wilcove, D.S. (2007) Cashing in palm oil for conservation. Nature, 448 (7517), 993-994.

McCarthy, J.F., Gillespie, P. and Zen, Z. (2012) Swimming upstream: Local Indonesian production networks in “globalized” palm oil production.World Development, 40 (3), 555-569.

Pardini, R., Bueno, A.dA., Gardner, T.A., Prado, P.I. and Metzger, J.P. (2010) Beyond the fragmentation threshold hypothesis: regime shifts in biodiversity across fragmented landscapes.PloS one, 5 (10), e13666.

Sodhi, N.S., Koh, L.P., Clements, R., Wanger, T.C., Hill, J.K., Hamer, K.C., Clough, Y., Tscharntke, T., Posa, M.R.C. and Lee, T.M. (2010) Conserving Southeast Asian forest biodiversity in human-modified landscapes.Biological Conservation, 143 (10), 2375-2384.

Vijay, V., Pimm, S.L., Jenkins, C.N. and Smith, S.J. (2016) The impacts of oil palm on recent deforestation and biodiversity loss. PLoS One, 11 (7), e0159668.

Wong, W.M., Leader-Williams, N. and Linkie, M. (2015) Managing human-sun bear conflict in Sumatran agroforest systems.Human Ecology, 43 (2), 255-266.

Wyborn, C. (2011) Landscape scale ecological connectivity: Australian survey and rehearsals.Pacific Conservation Biology, 17 (2), 121-131.





Why those holiday snaps may never look the same again….

From Sunday night Attenborough documentaries, to gap year photos from people you haven’t seen for years, we’re becoming increasingly informed about the world around us, enticing us to explore.

The Great Barrier Reef stretching the Queensland coastline is such a vast natural spectacle it can be seen from space. This complex ecosystem is home to over 450 types of coral and provides a habitat for marine creatures ranging from tropical fish to turtles (1), making it a popular holiday destination but for how much longer?

Lizard Island, Luxury Lodges of Australia, Queensland
Unbleached Coral reef community. Queensland (2)

This beautiful system is under threat from rising sea temperatures, putting stress upon the corals causing them to release the algae from their tissues leaving only ghostly white calcium skeletons remaining. Both the coral and the algae rely on their partnership for energy and safety.

These ‘bleached’ corals are unsustainable and will perish within weeks if the sea temperature fails to return to within tolerable ranges. Due to the certainty of rising ocean temperatures, restoration success is unlikely and the devastation likely to continue. (1)

Once a year the reef engages in mass reproduction, triggered by temperature and the lunar cycle, this supports continued reef biodiversity as well as providing an ample source of food for reef dwellers. A shift in the temperature cues for reproduction will have severe impacts on community biodiversity as compared to natural incidents global shifts cause a greater long term impact, reducing the possibility of recovery (3).

exclusive-coral-bleaching-in-new-caledonia2-1120x747
Coral bleaching event. Picture credit- The Ocean Agency / XL Catlin Seaview Survey / Richard Vevers  (4)

Environmental change that impacts the structure of the corals will also affect their functional ability within the community. (5) Corals provide shelter for many marine species, allow for protected migration and increased genetic flow through coral corridors.  This change alter the community structure and exasperate the global mass extinction we are currently experiencing.

So what is actually happening?

Global activities are impacting the future of this system dramatically, through climate change and our ever-increasing carbon footprint.

Corals extract calcium carbonate (the substance that forms eggshells) from the surrounding sea water to build the reef, using energy utilized from the algae within their structures. Each species builds differently to give beautifully diverse reefs, supporting creatures from zooplankton to green turtles.

Increasing atmospheric CO2, is absorbed by the oceans where its combined with seawater to produce an acid, leading to ocean acidification. This reduces the concentration of carbonate ions available for use by the corals to build their structures. (6)

These global changes aren’t the only driver of community shifts. On a local scale, flooding in Queensland has caused sediment and pesticide run off into the oceans. This increased nutrient input is devastating to a system reliant on diversity (7,8),  where some species are more susceptible to change than others, causing a decline in both population density and biodiversity.

So our holiday snaps might never look the same again… To mitigate this change we need to alter our way of life, just travelling to see them impacts their survival! But keep snapping and keep people talking, its the only way we are going to make change!

 

5.8 tonnes of COis released per person during a flight from London to Darwin Australia!! 

Flight # Details: Tonnes CO2
1 Return From London Gatwick to Darwin Australia 1 passenger 5.8

 

[500 Words]

 

References

  1. Australia’s Coral Reefs under Threat from Climate Change by Lesley Hughes, Will Steffen and Martin Rice (Climate Council of Australia).
  2. Great Barrier Reef | Australia’s Great Natural Wonder”. Great Barrier Reef. (2017). 21 Mar. 2017.
  3. Nyström, M., Folke, C., & Moberg, F. (2000). Coral reef disturbance and resilience in a human-dominated environment.Trends in Ecology & Evolution15(10), 413-417.
  4. The Ocean Agency. 2016. THE 3RD GLOBAL CORAL BLEACHING EVENT – 2014/2017. Available at: http://www.globalcoralbleaching.org/#essential-facts. [Accessed 21 March 2017].
  5. Richmond, R. H. (1993). Coral reefs: present problems and future concerns resulting from anthropogenic disturbance.American Zoologist33(6), 524-536.
  6. Hoegh-Guldberg, O., Mumby, P. J., Hooten, A. J., Steneck, R. S., Greenfield, P., Gomez, E., & Knowlton, N. (2007). Coral reefs under rapid climate change and ocean acidification.science318(5857), 1737-1742.
  7. Mongin, M., Baird, M. E., Tilbrook, B., Matear, R. J., Lenton, A., Herzfeld, M., & Duarte, C. M. (2016). The exposure of the Great Barrier Reef to ocean acidification.Nature communications7.
  8. Dubinsky, Z. V. Y., & Stambler, N. (1996). Marine pollution and coral reefs.Global change biology2(6), 511-526.




Climate change even sets plants up to compete

It is well known that plants photosynthesize and use carbon dioxide to produce energy and oxygen. But did you know that different photosynthetic pathways might have a huge impact on how plants will react to climate change? Continue reading “Climate change even sets plants up to compete”