The University of Southampton

Tag: global change

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.



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

Posted on by Lauren Scrace

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 CO2 is 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 & Evolution, 15(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 Zoologist, 33(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.science, 318(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 communications, 7.
  8. Dubinsky, Z. V. Y., & Stambler, N. (1996). Marine pollution and coral reefs.Global change biology, 2(6), 511-526.


Climate change even sets plants up to compete

Posted on by Selina Carlhoff

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” →



Humanity must stop neglecting changes in Seagrass Meadows before disaster?

Posted on by Anonymous

Seagrass meadows are a vital habitat and food source for many endangered species but these crucial habitats are under threat from environmental change caused by human impacts climate change, coastal developments, fishing and aquaculture (Waycott etal, 2009).

Figure 1- Manatee feeding on seagrass (USGS, 2016)
Figure 1- Manatee feeding on seagrass (USGS, 2016)

Climate Change

Climate change will cause a wide variety of impacts on the oceans which will effect seagrasses increasing water temperatures will lead to increased instances of seagrass die off, ocean acidification caused damaged to the cells plants require to photosynthesize and grow (Repolho et al, 2017).

As seagrass requires shallow habitats as sea levels rise there will be a loss of seagrass in deeper areas of their range seagrasses will move shoreward this trend is similar to trends that are being seen from increased amounts of sediments within the water as they will lack the sunlight to photsynthesise (Davis et al, 2016).

Coastal Developments

The construction of ports, artificial beaches and the reclamation of land, the adding of material to the water to fill in the area, this leads to more sediments within the water. The increased amount of sediments in the water can lead to seagrass beds being completely buried by the sediment and stopping plants from photosynthesising which it needs to survive, during the construction of the Pointe-Rouge Harbour over 68ha of seagrasses were lost due to water sediment and 11ha destroyed by construction (Boudouresque et al, 2009).

Figure 2- The Light grey shows dead seagrass and the dark grey living seagrass after the laying of a cable between two islands in the South of France (Boudouresque et al, 2009)
Figure 2- The Light grey shows dead seagrass and the dark grey living seagrass after the laying of a cable between two islands in the South of France (Boudouresque et al, 2009)

 

Fishing and Aquaculture

A trawler can uproot between 99,000-363,000 shoots during a trawl and in some areas of the Mediterranean over 80% of the seagrass meadows have been destroyed due to trawling (Boudouresque et al, 2009). Aquaculture, mainly fish farms, can cause a process called eutrophication, an excessive increase in nutrients heading into a body of water leading to high algal growth, because of the nutrients from uneaten food and excretion from the fish as it is focussed in one area around the fish farm this causes the reduction in size of the plants in the area due to reduced light reaching the plants, leading to a regression of the plants in the areas around fish farms (Ruiz et al, 2001).

pic-3
Figure 3- Changes in seagrass area by coastlines and in most coastlines more studies report a decrease (Waycott et al, 2009).

Future of Endangered Species

Dugongs, sea turtles and manatees all directly depend upon seagrass in many tropical regions for food and with decreases in seagrass globally, figure 3, they is likely to be further pressure put onto these already endangered species (Waycott et al, 2009), and if humanity does not take steps to solving the problems mentioned here the future of these iconic species is in real danger.

 

 

Reference List

Boudouresque, C., Bernard, G., Pergent, G., Shili, A., Verlaque, M., (2009), Regression of Mediterranean seagrasses caused by natural processes and anthropogenic disturbances and stress: a critical review, Botanica Marina, 52, 395-418

Davis, T., Harasti, D., Smith, S., Kelaher., (2016), Using modelling to predict impacts of sea level rise and increased turbidity on seagrass distributions in estuarine embayments, Estuarine, Coastal and Shelf Science, 181, 294-301

Repolho, T., Duarte, B., Dionísio, G., Paula, J., Lopes, A., Rosa, I., Grilo, T., Caçador, I., Calado, R. and Rosa, R. (2017). Seagrass ecophysiological performance under ocean warming and acidification. Scientific Reports, 7, p.41443.

Ruiz, J., Perez, M., Romero, J., (2001), Effects of Fish Farm Loadings on Seagrass (Posidonia oceanica) Distribution, Growth and Photosynthesis, Marine pollution bulletin, 42(9), 749-760

USGS, (2016). Manatees [online] Available at: https://www.usgs.gov/centers/wetland-and-aquatic-research-center-warc/science-topics/manatees [Accessed 20 Mar. 2017].

Waycott, M., Duarte, C., Carruthers, T., Orth, R., Dennison, W., Olyarnik, S., Calladine, A., Fourqurean, J., Heck, K., Hughes, A., Kendrick, G., Kenworthy, W., Short, F. and Williams, S., (2009). Accelerating loss of sea grass across the globe threatens coastal ecosystems,. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 106(30), 12377-12381

 

Word Count – 489

 

 

 



Will Intensifying Agriculture Save Us, or Starve Us?

Posted on by Deanna Fox

The surge in human population in recent years is predicted to reach an unprecedented 9.1 billion people by 2050 – a 14% increase of our current population (McKee et al., 2004). This epidemic of population growth means we are faced with the daunting challenge of attaining sustainable increase in crop production to meet the increasing food demands.

Anthropogenic disturbance in natural landscapes is one of the largest contributors to biodiversity loss. Here is the aftermath of land clearance for palm oil plantations, Borneo. Photo credit: Rhett A. Butler (2012). Available at: https://news.mongabay.com/2012/09/agriculture-causes-80-of-tropical-deforestation/
Anthropogenic disturbance in natural landscapes is one of the largest contributors to biodiversity loss. Here is the aftermath of land clearance for palm oil plantations, Borneo (Butler, 2012).

Global agricultural intensification has increased our food production to meet this demand through conversion of natural to simplified agricultural landscapes and escalating the application of agrochemicals such as pesticides and fertilisers (Matson et al., 1997). This simplification is a major cause of the accelerating loss of biodiversity, which affects ecological processes such as nutrient recycling, carbon storage and pollination (Flynn et al., 2009).

A biotic communities’ functional traits (i.e. characteristics) influences ecosystem functioning through mediating changes in biotic processes, such as predation and competition (Wood et al., 2015). For example, where there are collectively few traits in a community, circumstances of “niche overlap” are common, meaning ability to utilise a broad range of resources within a community decreases, whilst competition for a narrow selection resources increases (Flynn et al., 2009).

Figure 1: Theoretical total functional traits in natural, low-intensity agriculture, intensive agriculture, and managed through polyculture settings4.
Figure 1: Theoretical total functional traits in natural, low-intensity agriculture, intensive agriculture, and managed through polyculture settings (Wood et al., 2015).

Intensive agriculture may degrade (A) the number of functional traits in a given area (functional trait space). However, theoretically implementing adequate management strategies promoting multi-species crops (polycultures) may aid limited recovery of total functional traits (B), recovery to the levels of natural counterparts (C), or even exceed this (D) by endorsing evolution of new species with novel traits (figure 1).

Biodiversity loss through agricultural intensification has been reported for birds, insects, plants and mammals, along with functional trait diversity (Flynn et al., 2009).

 

 

 

“Between 1970 and 1990, 86% of farmland bird species had reduced ranges and 83% had declined in abundance [in Europe]” (Benton et al., 2003)

 

The resulting loss of functional traits (including foraging strategies and diet) has significant implications for the removal of insects from farmland, whereby insect subtraction is reduced. The disruptive effects this has on pest communities increases the risk of outbreaks, which not only influences community structures, but hinders crop productivity (Wood et al., 2015).

Application of pesticides to a monoculture crop in an attempt to control pest population. Photo credit Unknown. Available at: http://sitn.hms.harvard.edu/flash/2015/gmos-and-pesticides/
Application of pesticides to a monoculture crop in an attempt to control pest population (Hsaio, 2015)

Shifts toward monoculture (single-species) crops, and reduced predation, facilitates the spread of pests, increasing the risk of epidemics. Pesticides are commonly used as a control measure, although are often toxic to many species.  DDT, commonly used through the mid-20th century, accumulates in increasingly high concentrations up food chains between predators. This concentration may increase thousand-fold or more, of the content in the original source. This caused the endangerment of many predatory birds such as the peregrine falcon and kestrel through thinning their egg shells thus increasing infant mortality. Loss of top predators disrupts regulation of species populations further down the chain, unbalancing the community (Peakall, 1970).

Biodiversity loss is having severe adverse impacts on the health of our biotic communities, and therefore ecosystems. While agriculture cannot be halted all together, we could improve crop strength through diversity through implementing adequate management strategies to promote biodiversity, and use this to control pest outbreaks in an ecologically sensitive manner.

 

References

Benton, T. G., Vickery, J. A. and Wilson, J. D. (2003) ‘Farmland biodiversity: Is habitat heterogeneity the key?’, Trends in Ecology and Evolution, 18(4), pp. 182–188. doi: 10.1016/S0169-5347(03)00011-9.

Butler, R. A. (2012) Agriculture causes 80% of tropical deforestation, Mongabay. Available at: https://news.mongabay.com/2012/09/agriculture-causes-80-of-tropical-deforestation/ (Accessed: 21 March 2017).

Flynn, D. F. B., Gogol-Prokurat, M., Nogeire, T., Molinari, N., Richers, B. T., Lin, B. B., Simpson, N., Mayfield, M. M. and DeClerck, F. (2009) ‘Loss of functional diversity under land use intensification across multiple taxa’, Ecology Letters, 12(1), pp. 22–33. doi: 10.1111/j.1461-0248.2008.01255.x.

Hsaio, J. (2015) GMOs and Pesticides: Helpful or Harmful?, Harvard University: The Graduate School of Arts and Sciences. Available at: http://sitn.hms.harvard.edu/flash/2015/gmos-and-pesticides/ (Accessed: 20 March 2017).

Matson, P. A., Parton, W. J., Power, A. G. and Swift, M. J. (1997) ‘Agricultural Intensification and Ecosystem Properties.’, Science, 277(5325), pp. 504–509. doi: 10.1126/science.277.5325.504.

McKee, J. K., Sciulli, P. W., Fooce, C. D. and Waite, T. A. (2004) ‘Forecasting global biodiversity threats associated with human population growth’, Biological Conservation, 115(1), pp. 161–164. doi: 10.1016/S0006-3207(03)00099-5.

Peakall, D. B. (1970) ‘Pesticides and the reproduction of birds.’, Scientific American, 222, pp. 72–78. Available at: http://sitn.hms.harvard.edu/flash/2015/gmos-and-pesticides/.

Wood, S. A., Karp, D. S., DeClerck, F., Kremen, C., Naeem, S. and Palm, C. A. (2015) ‘Functional traits in agriculture: Agrobiodiversity and ecosystem services’, Trends in Ecology and Evolution. Elsevier Ltd, 30(9), pp. 531–539. doi: 10.1016/j.tree.2015.06.013.

 

[492 words]



Too Close To Home – The Effect Of Urbanisation on Global Wildlife

Posted on by Alexis Alders
Urban fox
Hobson (2015)

 

With increasing urbanisation of once wild landscapes, nature is forced to live right on our doorstep. With reports of vicious seagulls, giant rats, and foxes attacking babies, how is wildlife coping with living in the city?

 

Cities currently comprise around 3% of land globally (Faeth et al., 2011) and as this increases, more research is focusing on the animals we share our cities with. Urban development causes habitat fragmentation, enables the invasion of non-native species, and changes regional climates, which leads to a loss of wildlife. But what effect does the change in the environment have on the remaining flora and fauna?

 

In Mexico City, the number of bird species has decreased, but the number of birds overall has increased (Ortega-Alvarez and MacGregor-Fors, 2009). This was also found in butterflies in Mexico (Ramirez-Restrepo et al. 2015). Another pattern found in cities is a decrease in the number of species in more developed areas (Faeth et al. 2011). Decreases in the number of species towards the city centre is due to the avoidance of increased pollution, noise and light in these areas (Ortega-Alvarez and MacGregor-Fors, 2009). Artificial lighting affects the behaviour of bats (Hale et al 2015) and many species are sensitive to high human disturbance (Ortega-Alvarez and MacGregor-Fors, 2009). Few species can survive in cities, as they are inhospitable environments. Known as generalists, these species can eat food from more than one source and can survive in several habitats. Food is more available in the form of human rubbish (Ortega-Alvarez and MacGregor-Fors, 2009) which supports a larger abundance of animals. However, this increase in numbers is only seen in generalists, which can make use of this resource.

 

Which species can survive in a city is determined by hierarchical theoretical filters based on the environment (Aronson et al., 2016). A diagram of this can be seen below.

Urban hierarchical filters
Fig. 1 (Aronson et al., 2016, pg. 2954)

 

Generalists are more likely to meet these criteria due to flexibility within their characteristics. The structure of cities greatly impacts the species that live within them (Aronson et al. 2016). Management intensity in gardens is the main factor affecting spider communities, while bird communities are significantly affected by the abundance of woody plants (Sattler et al. 2010). Butterfly communities are structured by distance to city centre, and distance to well-preserved habitat both of which are linked to the overall structure of the city (Ramirez-Restrepo et al. 2015), as shown below:

City structure mosaic
Fig 1. (Nilon, 2011, pg.47)

So cities have massive effects on communities of wildlife. Therefore, is it inevitable that there will be human-wildlife conflicts? Not necessarily – urban wildlife can teach children living in urban environments about the natural world (Faeth et al., 2011). Additionally, increased biodiversity is linked to sustainable development and a reduction in poverty (Nilon, 2011). So although urban wildlife may be viewed as savage scroungers surviving at the fringes of our society, they actually represent a valuable resource.

 

References

Aronson, M.F., Nilon, C.H., Lepczyk, C.A., Parker, T.S., Warren, P.S., Cilliers, S.S., Goddard, M.A., Hahs, A.K., Herzog, C., Katti, M. and La Sorte, F.A., (2016) Hierarchical filters determine community assembly of urban species pools. Ecology, 97(11), pp.2952-2963.

Faeth, S.H., Bang, C. and Saari, S., (2011) Urban biodiversity: patterns and mechanisms. Annals of the New York Academy of Sciences, 1223(1), pp.69-81.

Hobson, S. (2015) How to photograph urban wildlife, available from: http://www.discoverwildlife.com/wildlife-nature-photography/how-photograph-urban-wildlife [accessed: 15/03/17]

Nilon, C.H., (2011) Urban biodiversity and the importance of management and conservation. Landscape and ecological engineering, 7(1), pp.45-52.

Ortega-Álvarez, R. and MacGregor-Fors, I., (2009) Living in the big city: Effects of urban land-use on bird community structure, diversity, and composition. Landscape and Urban Planning, 90(3), pp.189-195.

Ramírez-Restrepo, L., Cultid-Medina, C.A. and MacGregor-Fors, I., (2015) How many butterflies are there in a city of circa half a million people?. Sustainability, 7(7), pp.8587-8597.

Sattler, T., Borcard, D., Arlettaz, R., Bontadina, F., Legendre, P., Obrist, M.K. and Moretti, M., (2010) Spider, bee, and bird communities in cities are shaped by environmental control and high stochasticity. Ecology, 91(11), pp.3343-3353.

 

[Word count: 478]



Could crop and tree diseases completely alter the world we live in today?

Posted on by Holly Moser

Imagine Winnie the Pooh without One Hundred Acre Wood, Robin Hood without Sherwood Forest or Baloo without his prickly pears.

This cartoon was created to illustrate how all the trees were chopped to stop a 'killer fungus' (Adams, 2012)
This cartoon was created to illustrate how all the trees in the One Hundred Acre Wood were chopped down to stop a ‘killer fungus’ (Adams, 2012)

Back to the real world 

Acute oak decline Symptom: Profuse stem bleeding (Forestry Commission, 20170.
Acute oak decline
Symptom: Profuse stem bleeding (Forestry Commission, 2017).

The facts are that oaks are being decimated by acute oak decline (Forestry Commission, 2017), pears by fire blight (Johnson, 2000) and the Woodland Trust estimates that the UK could lose 130 million ash trees (Woodland Trust, 2017). These plants are part of our culture and economy but imagine how much worse it would be if you lived in the developing world and your staple diet was at risk.

Rice, the basic diet of half of the world’s population (FAO, 2013), is under threat from a serious disease called rice blast. Silicon is rice’s natural ‘knight in shining armour’ shielding it from this pathogen. Elevated CO2 levels are expected to decrease the plants silicon production, leaving rice vulnerable to its arch enemy and reducing overall yield (Elad and Pertot, 2014).

 

Invasion of the north

Scientists expect some pathogens such as Phytophthora cinnamomi  one of the world’s most invasive species to shift northwards due to warmer and wetter winters increasing the chance of overwinter survival in areas that are currently unsuitable (Burgess et al., 2017).

Although drier summers should have a counteracting effect, trees that have already been infected by P.cinnamomi are less likely to recover due to a reduced ability to take up water by rotting roots and increased drought stress (Burgess et al.,2017).

A map of the areas where P.cinnamomi already exists and the areas that may become more or less suitable for the invasion of P.cinnamomi with regards to future climate change.
A map of the areas where P.cinnamomi already exists and the areas that may become more or less suitable for the invasion of P.cinnamomi with regards to future climate change (Burgess et al., 2017).

Researchers are working against the clock to create new fungicides and develop disease resistant crops but these interventions appear to have some worrying knock on effects.

For example, researchers from the University of Exeter thought they might have a solution to ash dieback by breeding from older, resistant trees. However, it was recently discovered that that these older trees produce fewer chemicals to ward off the deadly emerald ash borer (University of Warwick, 2017). A double strike from ash dieback and emerald ash borers could wipe out ash in the UK!

Illustration of the Emerald ash borer and the damage it can cause to ash trees (Clark, 2013).
Illustration of the emerald ash borer and the damage it can cause to ash trees (Clark, 2013).

The news is not all bad

Although Baloo may lose his prickly pears, not all diseases are expected to increase with climate change and he may gain bananas. One disease expected to decrease in severity and frequency reducing the impact it has on global yield is black sigatoka a disease which decreases the leaf area in bananas reducing photosynthesis (Elad and Pertot, 2014 & Ploetz, 2001).

So where does that leave us?

There are still many gaps in plant disease research involving mechanisms of infection, resistance and the affect on plant function. There are also many unanswered questions- could a decrease in one disease kick off the invasion of another? Such factors make it impossible to predict the exact change to our landscape and crops. But the simple answer to my question is yes. Unless plant disease research achieves some major breakthroughs the chances are that our landscape will look very different and we may need to develop a taste for new foods.

 

 

References

Adams, 2012. Cartoon: One Acre Wood. Available from: http://www.englishblog.com/2012/10/cartoon-one-acre-wood.html#.WNMBBG-LTIX  [Accessed on: 16/03/2017].

Burgess, T.I., Scott, J.K., McDougall, K.L., Stukely, M.J.C, Crane, C., Dunstan, W.A., Brigg, F.,Andjic, V., White, D., Rudman, T., Arentz, F., Ota, N. and Hardy G.E.ST.J., 2017. Current and projected global distribution of Phytophthora cinnamomi, one of the world’s worst plant pathogens.  Global Change Biology; 23: 1661-1674.

Clark, P., 2013. Health and Science: The emerald ash borer’s domino effect on human health. Available from: http://www.washingtonpost.com/wp-srv/special/metro/urban-jungle/pages/130514.html [Accessed on: 21/03/2017].

Elad, Y. and Pertot, I., 2014. Climate change impacts on plant pathogens and plant diseases. Journal of crop improvement; 28 (1): 99-139.

FAO, 2013. FAO statistical year book 2013: world food and agriculture. FAO statistical year books, Rome, FAO: p.132. Available at: http://www.fao.org/docrep/018/i3107e/i3107e.PDF [Accessed on: 22/03/2017].

Forestry Commission, 2017. Acute Oak Decline. Available from: https://www.forestry.gov.uk/acuteoakdecline [Accessed on: 21/03/2017].

Johnson, K.B. 2000. Fire blight of apple and pear. The Plant Health Instructor. DOI: 10.1094/PHI-I-2000-0726-01. Updated 2015.

Ploetz, R.C. 2001. Black sigatoka of banana: The most important disease of a most important fruit.  The Plant Health Instructor.  DOI: 10.1094/PHI-I-2001-0126-02. Available from: http://www.apsnet.org/publications/apsnetfeatures/pages/blacksigatoka.aspx [Accessed on: 22/03/2017].

University of Warwick, 2017. Ash dieback- insect threat to fungus- resistant trees. Available from: https://phys.org/news/2017-01-ash-diebackinsect-threat-fungus-resistant-trees.html [Accessed on: 16/03/2017].

Woodland Trust, 2017. Protecting landscapes. Available from: https://www.woodlandtrust.org.uk/visiting-woods/tree-diseases-and-pests/what-we-are-doing/protecting-landscapes/ [Accessed on: 21/03/2017].

Word Count: 494



How do you like your toast in the morning? Without the worry of food security?

Posted on by Imogen Vieten

80% of human calorie intake comes from 6 major crops including – maize, wheat and rice1. For all people, at all times to have physical and economic access to sufficient food needed for a balanced diet2–food security, the production and distribution of these crops is vital.

Present day representation of global vulnerability to food insecurity8. Explore scenarios of Greenhouse gas emissions and adaptation to climate change impacts on food security by clicking on the link: http://www.metoffice.gov.uk/food-insecurity-index/ Present day representation of global vulnerability to food insecurity3. Explore scenarios of Greenhouse gas emissions and adaptation to climate change impacts on food security by clicking on the image.

A growing human population increases pressure to enhance crop production. 1 billion ha of land will be converted by 2050 for agriculture, reducing absorption of atmospheric carbon dioxide by plants2 and restoration of gaseous balance in the atmosphere, with fewer plants to act as a CO2 ‘sink’.

Human induced climate change is negatively affecting ecosystems, crop yield and production. Since the industrial revolution greenhouse gas emissions have risen, with atmospheric CO2 levels currently at 406.42ppm4, meaning plants are growing in conditions not experienced for 26 million years5.

Impacts of future climate change are predicted to be severe, varying between regions, through changes in temperature, precipitation and increases in extreme weather events. Methods of crop production such as sustainable intensification are needed to increase yields and overcome threats to livelihoods and food security2.

Will increased CO2 result in higher crop yields?

During photosynthesis plants use CO2, water and light to produce oxygen and carbohydrates for growth. Efficiency of this depends on the enzyme Rubisco, which functions better in high CO2, shown experimentally to increase photosynthesis by 58%5. There is evidence that the number and size of individual cells increase in elevated CO26, showing species specific adaptive ability7,  indicating potential to increase crop yield. However other climatic stresses will have negative effects.

The temperature dependant action of Rubisco may become less efficient with rising global temperatures. Furthermore in the long term, plants can acclimatise as additional carbohydrates produced from photosynthesis cannot be used5.

During extended periods of high CO2 exposure the number of stomata- pores used in gaseous exchange in leaves, may decrease indicating that photosynthetic rate will too7.

How will crop production be affected?

For sustainable intensification sufficient water and nutrients8 are required, which will be threatened by increased extreme weather events- from drought affecting water supply to storms where heavy downpours can wash away top soil, reducing land fertility.

Threats to global productivity and changes in yield could have impacts worldwide8. If production decreases, prices of grain products and meat reliant on grain as a feedstock will increase8. Furthermore lower agricultural output, especially in the developing world, leads to lower incomes, with the poorest suffering the most.

High CO2 can decrease food quality with a decline in protein, nitrogen, zinc and iron concentrations in crops9, potentially causing adverse health effects, and necessitating consumption of greater quantities.

Securing the future

FACE (Free-air concentration enrichment) experiments expose crops to elevated CO2 to examine responses and adaptions of ecosystems. Research to develop climate resilient crop varieties to better cope with heat, drought and salinity is also being conducted.

By adapting farming mechanisms and increasing yield and tolerance of essential crop species to environmental extremes, can we ensure food security? Yes, the time to act is now!

 

Discover more about how farmers may adapt their practices to a changing climate in the video ‘Feeding Nine Billion’10

 

[499 Words]

References

  1. Campell, N,A., Reece, J, B., Urry, L,A., Cain, M,L., Wasserman, S, A., Minorsky, P, V., Jackson, R, B. (2015). Seed Plants. In: Wilbur, BBiology A Global Approach. 10th ed. Essex: Pearson. p707.
  2. Sunderland, T., Powell, B., Ickowitz, A., Foli, S., Pinedo-Vasquez, M., Nasi, R. and Padoch, C. (2013). Food security and nutrition: The role of forests. Center for International Forestry Research. Discussion Paper, p1-20.
  3. Met Office. (2017).Food Insecurity Climate Change. Available: http://www.metoffice.gov.uk/food-insecurity-index/. Last accessed 18th March 2017.
  4. CO2 (2017). Earth’s CO2 home page. Available: https://www.CO2.earth/earths-CO2-main-page. Last accessed 20th March 2017.
  5. Drake, B, G. and Gonzàlez-Meler, M, A. (1997). More Efficient Plants: A Consequence of Rising Atmospheric CO2?.Annual Review of Plant Physiology and Plant Molecular Biology. 48, p609-639.
  6. Taylor, G., Ranasinghe, S., Bosac, C., Gardner, S and Ferris, R. (1994). Elevated CO2 and plant growth: cellular mechanisms and responses of whole plants. Journal of Experimental Botany. 45 (Special Issue). P 1761-1774
  7. Long, S, P., Ainsworth, E, A., Rogers, A. and Ort, D, R. (2004). Rising Atmospheric Carbon Dioxide: Plants FACE the Future.Annual Review of Plant Biology. 55, p591-628.
  8. Nelson, G, C., Rosegrant, M, W., Koo, J., Robertson, R., Sulser, T., Zhu, T., Ringler, C., Msangi, S., Palazzo, A., Batka, M., Magalhaes, M., Valmonte-Santos, R., Ewing, M. and Lee, D. (2009). Climate Change: Impact on Agriculture and Costs of Adaptation.International Food Policy Research Institute. Available at: http://www.fao.org/fileadmin/user_upload/rome2007/docs/Impact_on_Agriculture_and_Costs_of_Adaptation.pdf. Last accessed 19th March 2017
  9. Myers, S., Zanobetti, A., Kloog, I., Huybers, P., Leakry, A., Bloom, A., Carlisle, E., Dietterich, L., Fitzgerald, G., Hasegawa, T., Holbrook, N., Nelson, R., Ottman, M., Raboy, V., Sakai, H., Sartor, K., Schwartz, J., Seneweera, S., Tausz, M. and Usui, Y. (2014). Increasing CO2 threatens human nutrition. Nature, 510, p139-142
  10. Fraser, E. (2014). Feeding Nine Billion Video 6: Climate Change and Food Security. Available: https://www.youtube.com/watch?v=cYq2elstFWQ. Last accessed 18th March 2017.


Is Forest Fragmentation The “New” Deforestation?

Posted on by Ariadne Wilkinson
Global Forest Fragmentation is destroying our most important ecosystems.
Global Forest Fragmentation is destroying our most important ecosystems.

 

It’s a well-known fact that deforestation is happening at extreme rates! Just look at the Amazon rainforest, where 20 football pitches worth of trees are removed every minute (Carrington, 2013). These global environmental changes are associated with our topic for today: fragmentation!

.

WHAT IS FRAGMENTATION?

Forest fragmentation occurs when the total cover of a native forest is reduced. It is associated with anthropogenic deforestation, and leads to patchy forests and overall forest loss (Murcia, 1995) (Kupfer et al, 2006).

The isolated patches of forested habitats (remnants) in between the cleared forest cover follow the theory of ‘Island Biogeography’. Principles of Island Biogeography link forest fragmentation with biodiversity loss (Kupfer et al, 2006).

This is a good representation of forest fragmentation by Bacles & Jump (2011). The remnants have a drastically different ecosystem than their surroundings, just like an Island’s ecosystem is isolated from the outside world.
This is a good representation of forest fragmentation by Bacles & Jump (2011). The remnants have a drastically different ecosystem than their surroundings, just like an Island’s ecosystem is isolated from the outside world.

.

.

FRAGMENTATION EFFECTS ON ECOSYSTEMS

 

– Microclimate Change (Saunders et al, 1991)

The microclimate within and surrounding the remnant forest is altered in the following ways:

More solar radiation. This restricts shade-tolerant species and encourages the spread of new species of plants (ex. vines, secondary vegetation) and animals to occupy the forest clearings and edges.

The accompanied temperature rise alters soil moisture and nutrient availability, modifying the local vegetation. It also disturbs species interactions and animal foraging behaviours (ex. Carnaby’s cockatoos).

Image by Georgina Steytler: A Carnaby’s Black-Cockatoo (Calyptorbynchus funereus latirostrus). Higher temperatures in fragmented cockatoo habitats reduced their foraging time available, which led to their local extinction in areas of Western Australia (Saunders et al, 1991)
Image by Georgina Steytler: A Carnaby’s Black-Cockatoo (Calyptorbynchus funereus latirostrus). Higher temperatures in fragmented cockatoo habitats reduced their foraging time available, which led to their local extinction in areas of Western Australia (Saunders et al, 1991).

.

Stronger winds. Reducing the denseness of the forest leaves it more exposed to penetrating winds. That, amongst other things, changes vegetation structures and food availability for the forest communities.

Increased water flux. Fragmented forests alter the landscape through heavy water flows that erode the topsoil and transport more particulate matter across the forest cover.

 .

– Isolation (Saunders et al, 1991)

Remnant forest habitats are usually left crowded, with more species than they can actually support. Therefore, over time species will inevitably be lost due to the lack of resources and space available.

Species survival will generally depend on how well they can adapt to new conditions or migrate to new areas. The most rapid extinctions will occur for species with small populations, or ones that are heavily dependent on native vegetation or large territories.

.

– Greenhouse Effect

Tropical rainforests store large amounts of carbon. Destroying them releases this stored carbon into the atmosphere and largely contributes to global warming (Laurance et al, 2002).

.

.

MADAGASCAR

Fragmentation is a serious issue for this biodiversity hotspot, and its all due to human activities.

.

Fragmentation is a major concern for Madagascar: The original extent of the eastern rainforest was around 3 times larger than what it currently is!

.

Prior to human colonisation the forest on the eastern highland spine of Madagascar was 11.2 million ha, but by 1985 it only covered 3.8 million ha (Green & Sussman, 1990). (These satellite images can be found in Conservation Corridor).

.

Its size is diminishing due to fires, illegal logging and agricultural deforestation (Ganzhorn et al, 2001).

.

The forest on the Eastern Highland spine of the island is shrinking very fast. Forest can only survive within the gullies, where the fires can’t reach it. Image by: Josia Razafindramanana.
The forest on the Eastern Highland spine of the island is shrinking very fast. Forest can only survive within the gullies, where the fires can’t reach it. Image by: Josia Razafindramanana.

.

Many larger species have been lost, and the remainder are unlikely to maintain viable populations beyond 2040. Populations of lemurs with fewer than 40 adults cannot survive. Worryingly, none of the remnant patches on the eastern Madagascar forest are large enough to maintain even such populations (Ganzhorn et al, 2001).

.

Lemurs are holding on to the trees for dear life. The high rate of fragmentation is a major concern for these primates, as well as for all of Madagascar’s endemic forest ecosystems. Image by Frank Vassen
Lemurs are holding on to the trees for dear life. The high rate of fragmentation is a major concern for these primates, as well as for all of Madagascar’s endemic forest ecosystems. Image by Frank Vassen.

.

.

THE ONLY SAVING GRACE: CONNECTIVITY

Corridors to connect remnants have proven useful when striving to enhance biodiversity.

They can aid the re-colonisation and immigration of species, provide refuge, and help with further species interactions (Saunders et al, 1991) (Laurance et al, 2002).

The size and shape of the remnants can also affect its vulnerability to external factors:

The best conditions for the conservation management of the ecosystems within remnant patches or forest (here they are termed ‘reserves’ from the “Island-like reserves” biogeography theory) can be seen in this image. The theory of forest connectivity is linked to this.

.

 

Word Count: 499

.

FOR MORE INFORMATION ON:

Fragmentation effects on ecosystems you can watch: https://www.youtube.com/watch?v=lzf-uX6kGkk

How Madagascar is managing its lemur populations you can watch: https://www.youtube.com/watch?v=ZhOyD79ymJA

 

.

.

REFERENCES:          

          Carrington, D. (2013). Amazon deforestation increased by one-third in past year. [online] the Guardian. Available at: https://www.theguardian.com/environment/2013/nov/15/amazon-deforestation-increased-one-third [Accessed 18 Mar. 2017].

          Ganzhorn, J., Lowry, P., Schatz, G. and Sommer, S. (2001). The biodiversity of Madagascar: one of the world’s hottest hotspots on its way out. Oryx, 35(04), p.346.

          Green, G. and Sussman, R. (1990). Deforestation History of the Eastern Rain Forests of Madagascar from Satellite Images. Science, 248(4952), pp.212-215.

          Kupfer, J., Malanson, G. and Franklin, S. (2006). Not seeing the ocean for the islands: the mediating influence of matrix-based processes on forest fragmentation effects. Global Ecology and Biogeography, 15(1), pp.8-20.

          Laurance, W., Lovejoy, T., Vasconcelos, H., Bruna, E., Didham, R., Stouffer, P., Gascon, C., Bierregaard, R., Laurance, S. and Sampaio, E. (2002). Ecosystem Decay of Amazonian Forest Fragments: a 22-Year Investigation. Conservation Biology, 16(3), pp.605-618.

          Murcia, C. (1995). Edge effects in fragmented forests: implications for conservation. Trends in Ecology & Evolution, 10(2), pp.58-62.

          SAUNDERS, D., HOBBS, R. and MARGULES, C. (1991). Biological Consequences of Ecosystem Fragmentation: A Review. Conservation Biology, 5(1), pp.18-32.

 

 



Eutrophication: A powerful poison to aquatic life

Posted on by Xi Lan

 

3Such tragic pictures were taken in China telling stories of the low-income people who live on fisheries lost their fishes due to the algae bloom. However, this problem does not only present in China: according to reports, during 1972 to 1999 US commercial fisheries lost over 18 million dollars every year due to the poor water quality (National Science Foundation, 2000).

 

2

How is it developed?

Under warm and excessive nutrient conditions (e.g., introduction of nitrogen and phosphorus), algae in the lake starts to grow rapidly. In most healthy lakes, all depths are well oxygenated and the species in lakes are diverse. The excessive nutrient loads leads to the dominance of algae to the lakes, in other word, algae bloom. Massive algae bloom in the surface results in water turbidity increasing therefore the sunlight is blocked from underwater plants. Additionally, algae in the lakes has a short lifespan and depletes the oxygen in water causing a death zone along the water column (hypoxia); some algae can release toxins which are deadly to fish (Hallegraeff, 1993). In this stage the amount of fishes along with aquatic plants decreases rapidly. The healthy, well-oxygenated and clear lake becomes turbid, unsightly with few species alive and a disgusting smell.

 

What happens to ecosystem within the lake?
1The submerged aquatic plants which are adapted themselves to original lake conditions (e.g. high concentration of chlorophyll) are almost wiped out from the lakebed during the algae bloom (Jupp and Spence, 1977). In the case of Taihu lake in China, the area covered by submerged aquatic plants was over 530 km2 which reduced to around 300 km2   in 2009 (Qin et al., 2012).

The decreasing amount aquatic plants would have an impact to the zooplanktons. Less coverage of submerged aquatic plants on lakebed means less refuge capacity provided for zooplanktons (SCHRIVER et al., 1995). Therefore, besides the pressure of hypoxia, zooplanktons are struggling to survive at high predation risk.

One pronounced impact of lake eutrophication is the decreasing trend of overall fish population along with rising algal population as oxygen depleted environment is no longer able to hold big fish population as a healthy lake. Aparting from decreasing quantity of fish community, the fish community quality is also under threat. Generally, highly eutrophic lakes often are dominated by ferocious fish species such as carp (Lee and Jones, 1991). They are more adapted to the poorly oxygenated environment and they are voracious predator of zooplanktons that eat algae, which is an enhancing factor of lake eutrophication (Reinertsen et al., 1990). Decreasing fish community diversity could also happen when low oxygen condition driving deep-water living fish coming to open water under oxygen pressure which result in hybrid with open water fish.

 

Human interference to the ecosystem

Under such environmental pressure, countries like China decides to apply biotic approach to solve the algae bloom causing by eutrophication. Deploying algae-munching fish is well-known as approach to regulate algae population (Andersson et al., 1978). However, massive releasing algae-munching fish would dramatically changing the composition of current aquatic community leading unpredictable problems in future.

 

 

 

References

Andersson, G., Berggren, H., Cronberg, G. and Gelin, C. (1978). Effects of planktivorous and benthivorous fish on organisms and water chemistry in eutrophic lakes. Hydrobiologia, 59(1), pp.9-15.

Hallegraeff, G. (1993). A review of harmful algal blooms and their apparent global increase*. Phycologia, 32(2), pp.79-99.

Jupp, B. and Spence, D. (1977). Limitations on Macrophytes in a Eutrophic Lake, Loch Leven: I. Effects of Phytoplankton. The Journal of Ecology, 65(1), p.175.

Lee, G. and Jones, A. (1991). Effects of Eutrophication on Fisheries. Reviews in Aquatic Science, [online] 5(3). Available at: http://www.gfredlee.com/Nutrients/Effects_Eutroph_Fisheries.pdf             [Accessed 22 Mar. 2017].

McKinnon, J. and Taylor, E. (2012). Biodiversity: Species choked and blended. Nature, 482(7385), pp.313-314.

National Science Foundation, (2000). Estimated Annual Economic Impacts from Harmful Algal Blooms (HABs) in the United States. [online] National Science Foundation. Available at:                       http://www.whoi.edu/cms/files/Economics_report_18564_23050.pdf [Accessed 22 Mar. 2017].

Qin, B., Gao, G., Zhu, G., Zhang, Y., Song, Y., Tang, X., Xu, H. and Deng, J. (2012). Lake eutrophication and its ecosystem response. Chinese Science Bulletin, 58(9), pp.961-970.

Reinertsen, H., Jensen, A., Koksvik, J., Langeland, A. and Olsen, Y. (1990). Effects of Fish Removal on the Limnetic Ecosystem of a Eutrophic Lake. Canadian Journal of Fisheries and Aquatic             Sciences, 47(1), pp.166-173.

SCHRIVER, P., BOGESTRAND, J., JEPPESEN, E. and SoNDERGAARD, M. (1995). Impact of submerged macrophytes on fish-zooplanl phytoplankton interactions: large-scale enclosure                         experiments in a shallow eutrophic lake. Freshwater Biology, 33(2), pp.255-270.

 

word count: 496