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Imaggeo on Mondays: Dragon Blood Tree

Imaggeo on Mondays: Dragon Blood Tree

On a small and isolated island in the Indian Ocean you’ll find an endemic population of Dragon Blood Trees (Dracaena cinnabari). Burly, with an interesting umbrella-shaped fractal canopy, these unique trees are a sight to behold.

To see them for yourself, you’ll have to travel to the little known Socotra archipelago. Off the coast of Somalia, but belonging to Yemen, the group of islands boast an impressive assortment of endemic plant life, making them know as the ‘Galapagos of the Middle East’.

Crucial to the uniqueness of the flora and fauna of the archipelago is Socotra’s geographical position and how it came to be there. The African plate extends out from the Horn of Africa, east of the Guardafui graben, in what is known as the Socotra Platform. Here you’ll find four islands, of which Socotra is the largest, as well as two scars of former islands which have been eroded away by wave action.

At in excess of 240 kilometres east of the Horn of Africa and 380 kilometres south of the Arabian Peninsula there is no getting away from the remoteness of the archipelago. Testament to this is the presence of seven endemic bird species on the island.

So how did the strange looking Dragon Blood Tress and other flora and fauna come to populate Socotra and its neighbours?

It is thought that until 43 million years ago, the Socotra archipelago remained largely submerged. Although there were some brief emergence events during the Jurassic/Cretaceous and Cretaceous/Tertiary, given the area was re-submerged after this time, they are considered of little importance.

Subsequently, Socotra Island continued to grow due to uplift. Despite changing sea depths, there are indications that land species could migrate over from mainland African and Arabia via land bridges and stepping stones. With ‘cousin’ species present in Somalia and Arabia, it’s likely the Dragon Blood Trees originated there in the distant past.

From 16,000 years ago onwards, the isolation of the archipelago grew due to a combination of further flooding of low-lying areas, the formation of large basins (namely the Guardafui and Brothers basin) and increasing distance from the mainland. Since then, the species on Socotra and its neighbouring islands have had time to evolve and adapt to their surroundings, become different, albeit sometimes closely related, to their continental counterparts.

It was only around the third century BC that Socotra started to emerge from its isolation after attracting the attention of the young Alexander the Great during one of his war campaigns. The island then became known in the Hellenic World and all the Mediterranean for being one of the main sources of incense, myrrh and dragon’s blood powder resin.

As Socotra commercial importance gradually faded away in the centuries to follow, Dragon’s Blood resin remained one of the main exports of the island. The resin was considered a precious ingredient of dyes, lacquers and varnishes, and the legend has it that Antonio Stradivari – the famous seventeenth century luthier from Cremona – used Socotra’s red resin to varnish his violins.

yemen

The landscape of the Socotra archipelago. Credit: Annalisa Molini via Flickr.

One thing is for sure, as Annalisa Molini’s (Assistant Professor at the Institute Center for Water and Environment, in Abu Dhabi), photographs attest to: Socotra island and it’s Dragon Blood Trees are stunning.

However, the remoteness of the Socotra archipelago and the current armed conflict in Yemen threaten to put at risk the island’s important and unique natural heritage; one that no doubt, should be protected and preserved.

References

M. Culek: Geological and morphological evolution of the Socotra Archipelago (Yemen) from the biogeographical view, Journal of Landscape Ecology, 6, 3, 84–108, DOI: 10.2478/jlecol-2014-0005, 2014

Brown, B.A. Mies, Vegetation Ecology of Socotra, Springer Netherlands, Dordrecht, 2012. doi:10.1007/978-94-007-4141-6.

Imaggeo is the EGU’s online open access geosciences image repository. All geoscientists (and others) can submit their photographs and videos to this repository and, since it is open access, these images can be used for free by scientists for their presentations or publications, by educators and the general public, and some images can even be used freely for commercial purposes. Photographers also retain full rights of use, as Imaggeo images are licensed and distributed by the EGU under a Creative Commons licence. Submit your photos at http://imaggeo.egu.eu/upload/.

The EGU Network blogs are looking for guest contributions

Are you a budding science writer, or want to try your hand at science communication? You might just be the person for our EGU network bloggers! A number of our network blogs would like to give their pages a bit of a boost and are seeking guest bloggers to contribute new, informative and engaging posts on an ad hoc basis.

If you’ve recently been thinking about trying your hand at blogging, but aren’t sure if it’s for you or simply have a great story or research that you’d like to see ‘in print’, why not give guest blogging a try? Read on to find out which blogs are looking for contributions.

Four Degrees

4degreesWritten by Flo Bullough and Marion Ferrat , Four Degrees, looks at environmental geoscience issues from a science for policy perspective. Environmental geochemistry, climate change, policy and sustainability are brought together in this blog and explored at the interface between science and society.

Flo and Marion are looking for guest contributions, but would also be happy to welcome a more regular blogger to their team. So if you are interested in geoscience and policy and are looking for the opportunity to get into some regular science writing, fill out this form and Flo and Marion will be in touch soon!

Geology for Global Development (GfGD)

GfGDGfGD is a UK-based organisation, working to support young geologists to make an effective contribution to international development. The network blog is a place for the organisation to share articles, discussions, photographs and news about the role of geology within sustainable development and the fight against global poverty

Blog editor, and founder of the organisation, Joel Gill, has his hands full running the blog, the organisation and completing his PhD. As a result, the blog is particularly looking for guest contributions which explore the principles of international development and how the earth sciences can make a difference. Take a look at the blog for some inspiration and pitch your ideas to Joel using this form.

Geology Jenga

JengaA broad range of topics find their way into the posts of Geology Jenga, with authors Dan Schillereff and Laura Roberts Artal writing about all things science communication, their careers as budding academics, as well as the science behind geophysics and geomorphology.

However, since finishing their PhDs, the demands of their 9 to 5 jobs mean that Dan and Laura have less time to write and would welcome guest contributions on any of the topics above. If you’d like to contribute to the blog, why not get in touch with them using this form?

GeoSphere

GeoSphereThe term geosphere is an all-encompassing word that incorporates just about every aspect of the earth sciences. This means that topics ranging from geophysics to geochemistry to geobiology are part of the geosphere. The blog Geosphere honours its namesake by covering any and every topic in the geosciences. However, with blog author, Matt Herod’s research interests in geochemistry and hydrogeology you’ll likely find more posts on these topics.

Matt aims to make science clear for anyone that should stumble upon the geosciences and enhance awareness of the geosphere. If these goals resonate with you, then you writing for the Geosphere blog might just be the thing for you. Why not get in touch with Matt using this form?

Polluting the Internet

PollutingWill Morgan, an atmospheric sciences researcher from the University of Manchester, blogs at Polluting the Internet. Focusing on tiny particles suspended in our atmosphere, called aerosols, which can build up and pollute our skies. In the blog, Will explores current research in aerosol science, as well as his fieldwork exploits in pursuit of these tiny particles.

If this is your area of research too and you’d like to contribute a guest blog post on the subject, why not give it a go! You can get in touch with Will by filling out this form.

Green Tea and Velociraptors

GreenWhilst swamped by the writing of the thesis, Jon welcomes guest contributions to his blog too. Covering the subject of palaeontology as well as regularly writing about science communication and the open science movement, the blog has a diverse readership and offers a great platform for anyone how has something to say about these topics. Get in touch with Jon using this form.

The network blogs cover a range of topics in the Earth, planetary and space sciences, with the aim to foster a diverse community of geoscientist bloggers. If you’d like to submit a guest blog post, please fill out the forms available above. For general guest blogging guidelines, please refer to the submit a post page on the EGU official blog GeoLog.

Geosciences Column: When water is scarce, understanding how we can save it is important

Geosciences Column: When water is scarce, understanding how we can save it is important

Supplies of water on Earth are running dry. The rate at which an ever growing population consumes this precious resource is not matched by our Planet’s ability to replenish it. Water scarcity is proving a problem globally, with regions such as California and Brazil facing some of the most severe water shortages on record. Used for drinking, agriculture and industrial processes, water forms an fundamental part of our day to day life, so finding ways in which to preserve this vital resource is important.

The global population now exceeds 7.3 billion people. One of the greatest challenges of the 21st century will be to feed this ever growing population – by 2050 crop production will have to double to meet demand. At the same time, agricultural irrigation currently accounts for approximately 80-90% of global freshwater consumption, while agricultural areas requiring irrigation in the past 50 years having roughly doubled. With both space and freshwater in short supply, innovative solutions and fresh approaches will be need if the increase in crop demand is to be met.

The fields in the image are farmed on seemingly vertical hillsides, terrace their fields nearly to the top of every available mountain, and plough by hand or with a draft animal. Terraces, by Cheng Su, distributed via Imaggeo.

The fields in the image are farmed on seemingly vertical hillsides. Terraced fields are  present nearly to the top of every available mountain, and ploughed by hand or with a draft animal. Terraces, by Cheng Su, distributed via imaggeo.

It might come as a bit of a surprise that current irrigations systems operate at efficiency of 50% or below. Water is wasted as it is transported to the crops as well as whilst it is applied to the plants and is affected, not only by the irrigation system itself, but also meteorological and environmental factors. A recent paper published in the open access, EGU Journal, Hydrology and Earth System Sciences, has found that improving current irrigation practices can contribute to sustainable food security.

To better understand where efficiencies might be made in irrigation systems, the scientists used a new approach: They took into account ‘manageable’ factors such as water lost through evaporation, run-off, deep percolation and that taken on by weeds. At the same time, assessing mechanical performance of the systems and the vegetation dynamics, climate, soils and land use properties of a particular region. These factors were fed into a global irrigation model implemented on the three main irrigation types: surface, sprinkler and drip.

The researchers created maps of the global distribution of irrigation systems at a country level, based on the results from their model. The maps showed that areas where surface irrigation – were water is distributed over the surface of a field – is common, irrigation system efficiency was low, sometimes registering values of less than 30%! This is particularly applicable to Central, south and Southeast Asia due to the widespread cultivation of rice. In contrast, areas where there is a high usage of sprinkler systems – similar to natural rainfall – and drip systems (were water is allowed to drip slowly to the root of the plant), such as North America, Brazil, South Africa, Ivory Coast and Europe, efficiency was above the global average.

Global patterns of beneficial irrigation efficiency (Eb, ratio of transpired and diverted water) for each irrigation system – (a) surface, (b) sprinkler, and (c) drip, calculated as area-weighted mean over CFTs (excl. “others” and pastures). This figure is based on theoretical scenarios, in which each system is respectively assumed to be applied on the entire irrigated area.

Global patterns of beneficial irrigation efficiency for each irrigation system (a) surface, (b) sprinkler, and (c) drip. This figure is based on theoretical scenarios, in which each system is respectively assumed to be applied on the entire irrigated area. From Jägermeyr et al., 2015. Click to enlarge.

To investigate how the three irrigation system types compared to one another, irrespective of their geographical distribution, the researchers produced another map. They found that surface irrigation is the least efficient of the three methods, with values at less than 29%. Sprinkler and drip systems perform significantly better, with values of 51 and 70%, respectively. Interestingly, regardless of the system used, irrigation efficiency in Pakistan, northeast India and Bangladesh is always at below global average values. Crop type can also play an important role: rice, pules and rapeseed are linked to poor system efficiencies, whilst, maize sugarcane and root crops (such as potatoes) are above average.

Jägermeyr, the study’s lead author, and his team calculated that 2469km³ of water is withdrawn yearly for irrigation purposes – that is close to 5 times the volume of water held in the Canadian/American Lake Erie. Of that, 608 km³ is non-beneficially consumed. In other words, lost through evaporation, interception (by foliage leaves) and during delivery to the plants and represents an area where substantial water savings could be made.

Replacing surface irrigation with a sprinkler or drip system proves one of the best solutions to the problem, with a potential 76% reduction in non-beneficial consumption of water. This would mean that up to 68% less water would be needed for the purposes of irrigating crops.

Therefore, irrigation system improvements could make an important contribution to sustainably increase food production. The water saved would allow for irrigated areas to be expanded and yields increased on farms where production is currently limited by an insufficient water supply.

The upgrade of irrigations systems seems a very attractive solution to the problem, but the researchers warn that its suitability must be assessed on a river basin level. Factors such as crop management, soil type and local climate may affect the suitability of this approach in some geographical areas. The study finds that regions such as the Sahel, Korea and Madagascar, as well as temperate regions in Europe, North America, Brazil and parts of China would benefit the most from irrigation system improvements.

 

By Laura Roberts Artal, EGU Communications Officer.

 

References

Jägermeyr, J., Gerten, D., Heinke, J., Schaphoff, S., Kummu, M., and Lucht, W.: Water savings potentials of irrigation systems: global simulation of processes and linkages, Hydrol. Earth Syst. Sci., 19, 3073-3091, doi:10.5194/hess-19-3073-2015, 2015.

Gleick, P.H., Christian-Smith, j., Cooley, H.: Water-use efficiency and productivity: rethinking the basin approach, Water International, 36, 7, doi: 10.1080/02508060.2011.631873, 2011.

Tilman, D., Blazer, C., Hill, J., Befort, B.L.: Global food demand and the sustainable intensification of agriculture, PNAS 108, (50), 20260-20264, doi:10.1073/pnas.1116437108, 2011.

Film review: Revolution

Film review: Revolution

It’s not every day you are asked to review a film, and since it’s a documentary that encompasses a few of EGU’s sciences (such as climate sciences, biogeosciences, and energy, resources and the environment), I couldn’t say no. I’ll start by giving it a rating, 3.5/5 stars, though I would probably give it more if I were part of the film’s main target audience.

Revolution, by biologist-photographer turned filmmaker-conservationist Rob Stewart, is about some of the most pressing environmental issues of our time. It aims to educate the audience about ocean acidification, climate change, overfishing and deforestation, alerting them to how these issues can impact our planet and, in turn, humanity. But it’s also about much more than that.

The film starts with Stewart telling his own story, revealing how his personal experiences lead him to make his first documentary, Sharkwater, and how researching and promoting that film made him want to tell the broader story of Revolution. This makes for good story telling, and it’s an interesting and candid introduction (Stewart says at one point that he had no idea how to make a movie before Sharkwater). But it seems a tad overly dramatic at times and not always scientific in its claims. For example, to illustrate how humans, responsible for many environmental problems, can also be part of their solution, Stewart tells a crowd in Hong Kong that the “holes in the ozone layer are almost a figment of our imagination now”, which is not exactly true. According to a 2014 NASA release, the ozone hole is still roughly the size of North America, though it has been shrinking over the past couple of decades. I should point out, however, that while there are some minor scientific inaccuracies here and there in the film (and a glaring typo in a sentence where CO2 appears incorrectly written as CO2) the majority of the facts and figures cited in the movie do roughly seem to be accurate, even if rather dramatic and seemingly exaggerated at first.

The movie becomes more exciting (though, at times, depressing too) when Stewart changes the focus from his story to the story of how life evolved on Earth, and what its future might look like. The backdrop is beautiful footage, worthy of a BBC wildlife programme. Stewart starts where life itself started, underwater, and the images showing a diversity of corals and colourful fish (and the cute pigmy sea horse) are breath-taking and work well in illustrating his points. For example, as the colourful imagery gives place to shades of grey, Stewart describes and shows how corals have been affected by ocean acidification and rising temperatures.

Coral cover on the Great Barrier Reef has declined by 36% over the last 25 years. That's an enormous loss. Photo © Rob Stewart. From the documentary film Revolution.

Coral cover on the Great Barrier Reef has declined by 36% over the last 25 years. That’s an enormous loss. Photo © Rob Stewart. From the documentary film Revolution.

If the footage, both underwater and on land, makes for a stunning background, the interviews with various scientific experts bring home the film’s key messages. To me, they are the strongest aspect of Revolution. Stewart talks to credible researchers who are able to communicate their, often complex, science in clear language. Some of the readers of this blog may be able to relate to scientists Charlie Veron and Katharina Fabricius, whose field work is shown in the film, while viewers less familiar with the effects of ocean acidification on coral reefs will likely be moved by the dramatic words of these researchers.

What the scientists tell us will happen if humans continue in the business-as-usual path is indeed gloomy: deforestation increasing, fisheries collapsing, greenhouse gas emissions and temperatures on the rise at unprecedented rates, species going extinct en masse… the list goes on. The issues of deforestation and mass extinction are addressed when Stewart travels to Madagascar: the island’s tropical dry forests are home to unique animals and plants, many of which have seen their habitats destroyed by the burning of trees to make room for pastures and crops. Humanity’s dependence on fossil fuels is illustrated when Stewart talks about the Alberta tar sands, and how resource intensive and polluting it is to extract oil from them. A key message of the film is again illustrated here by one of the experts interviewed. Hans Joachim (‘John’) Schellnhuber, a scientific advisor to the German Government and director of the Potsdam Institute for Climate Impact Research, explains how stopping the Canadian tar sands project “is one of the decisive battles in the war against global warming”.

Indeed, Stewart sets out not only to inform people about the environmental issues faced by humanity, but also to encourage the audience to act on them: “Revolution is not just about the environment – it’s a film about hope and inspiration.” As such, Stewart balances out this negative outlook with examples of people who are standing up for climate justice and fighting for an end to fossil-fuel burning (and, sometimes, with clips of flamboyant cuttlefish and jumping lemurs!). Although it may not seem like it halfway through the film, the overall message is positive.

This is most evident when Stewart talks to young people, particularly those who travelled to Cancun, Mexico for the United Nations Climate Change Conference in 2010 (COP16). It is heartening to find out how committed and courageous some young people are in fighting for our future, their future, and in wanting to make the Earth a better place by changing human behaviour. This fighting spirit is best encapsulated in a speech by Mirna Haider, from the COP16 Lebanon Youth Delegation, which is particularly bold and moving, if impatient: “You have been negotiating all my life, you cannot tell me you need more time.”

Flamboyant Cuttlefish. Photo © Rob Stewart. From the documentary film Revolution.

Flamboyant Cuttlefish. Photo © Rob Stewart. From the documentary film Revolution.

Young people are those who may have the most to benefit from watching this film, and I think are the primary target audience of Revolution (there’s even an accompanying Educator’s guide with pre- and post-viewing resources and classroom activities teachers and parents might find useful). It inspires them towards (peaceful) revolution against corporations who profit from burning fossil fuels and from destroying natural resources, and against governments who take no action to stop them. It is a shame the film doesn’t address other ways in which individuals could help fight climate change, deforestation and ocean acidification, such as divesting from fossil fuels or eating less meat. But perhaps that’s something that resonates better with older people. Children and teenagers tend to be more optimistic about their power to save the Planet through revolution, and this film is sure to inspire them to act on the most pressing environmental problems the Earth faces.

Revolution premiered at festivals in 2012/2013, but has only been widely released earlier this year. You can watch the film online on the Revolution website, or through the platforms indicated there (sadly, it’s not free, but you can either rent it or buy it for only a few dollars, so it’s certainly affordable!).

 

By Bárbara Ferreira, EGU Media and Communications Manager

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