All posts by Garry Peterson

Prof. of Environmental science at Stockholm Resilience Centre at Stockholm University in Sweden.
Visualization

UK energy flow chart 2007

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From the UK’s Department of Business Enterprise and Regulatory Reform

UK Energy Flow Chart

It is based on statistics taken from the Digest of United Kingdom Energy Statistics 2008, Table 1.1 – Energy Balance 2007. The flow chart is a simplification of these figures, illustrating the flow of primary fuels from the point at which they become available from home production or imports (on the left) to their eventual final uses (on the right). They are shown in their original state and after being converted into different kinds of energy by the secondary fuel producers. The flows are measured in million tonnes of oil equivalent, with the widths of the bands approximately proportional to the size of the flow they represent.

More detailed flow charts are available by fuel on the BERR website.

I previously posted WRI’s world greenhouse gas emissions flowchart.

General

The Shrinking Aral Sea

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Another image showing the ecological destruction of the Aral Sea.

Aral Sea 2000-2008

From EO Newsroom:

This natural-color satellite image shows the Aral Sea on August 16, 2008. The colored contour lines show the approximate shorelines of the sea since 2000. The image is from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite. The contour lines are based on MODIS data from both the Aqua and Terra satellites. The image documents the progress of a conservation plan to stabilize the North Aral Sea, and the continued decline of the South Aral Sea. Deeper, clearer waters are darker blue; shallower, murkier waters are greenish.

A dam separates the northern and southern parts of the sea, allowing the flow of the Syrdar’y to recharge the North Aral Sea. Meanwhile, the South Aral Sea continues to dry out. The lake has split into eastern and western lobes, with the eastern lobe drying more rapidly. The lakebed is lined with pale, salty sediment, which is kicked up during dust storms. The lakebed sediments also contain agricultural chemical residues and other pollutants, which have contributed to widespread public health problems.

The transformation of the lake into dry land changed the regional climate. Previously, the large lake helped to stabilize the area’s continental climate. Continental climates exhibit large seasonal extremes in temperature. Compared to locations at the same latitude, places with continental climates have hotter summers and colder winters; they are also drier. As the Aral Sea has disappeared, summers have become even hotter, winters have become colder and longer, and the dry climate has become drier.

Visualization

Geography and Genes

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From the New York Times reporting on an article by Oscar Lao and others in Current Biology:

A genetic map of Europe

The map shows, at right, the location in Europe where each of the sampled populations live and, at left, the genetic relationship between these 23 populations. The map was constructed by Dr. Kayser, Dr. Oscar Lao and others, and appears in an article in Current Biology published on line on August 7.

The genetic map of Europe bears a clear structural similarity to the geographic map. The major genetic differences are between populations of the north and south (the vertical axis of the map shows north-south differences, the horizontal axis those of east-west). The area assigned to each population reflects the amount of genetic variation in it.

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Data for the map were generated by gene chips programmed to test and analyze 500,000 sites of common variation on the human genome, although only the 300,000 most reliable sites were used for the map. Dr. Kayser’s team tested almost 2,500 people and analyzed the data by correlating the genetic variations in all the subjects. The genetic map is based on the two strongest of these sets of correlations [the principal components used to plot the data above – these explained 31.6% and 17.3%, of the total variation.  The potential geographic basis of these two PCs was supported by a positive correlation (r2 = 0.6) between the genetic and  geographic distances among the samples.].

The gene chips require large amounts of DNA, more than is available in most forensic samples. Dr. Kayser hopes to identify the sites on the human genome which are most diagnostic for European origin. These sites, if reasonably few in number, could be tested for in hair and blood samples, Dr. Kayser said.

Genomic sites that carry the strongest signal of variation among populations may be those influenced by evolutionary change, Dr. Kayser said. Of the 100 strongest sites, 17 are found in the region of the genome that confers lactose tolerance, an adaptation that arose among a cattle herding culture in northern Europe some 5,000 years ago. Most people switch off the lactose digesting gene after weaning, but the cattle herders evidently gained a great survival advantage by keeping the gene switched on through adulthood.

Visualization

Agricultural involution in the IJsselmeer, Netherlands

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NASA Earth Observatory shows agricultural development and divisions on reclaimed land in the man-made IJsselmeer in the Netherlands. Over time the heterogenity of the newly created land shown in the image as fields are divided and land uses have diversified.

NASA image of land reclamation in NL

NASA Earth Observatory explains:

NASA’s Landsat satellites captured repeated images of IJsselmeer, and recorded changes on one such polder, shown in the top-middle part of each image. Landsat 2 took the top picture on September 8, 1980. Landsat 5 took the middle picture on May 23, 1989. Landsat 7 captured the bottom image on July 1, 2006. In these false-color images, red indicates vegetation, and the brighter the red, the more robust the plant life. Water appears navy blue. Pavement and bare soil range in color from pale blue to gray-green.

Visualization

Archetypical landscape of the USA

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Jeff Cardille at the University of Montreal has a project METALAND that is eveloping more sophiticated ways of characterizing landscapes.  He presented some of his work on archetypical landscapes of the USA at the current Ecological Society of America meeting.

Jeff Cardille 17 archetypical landscapes of USA

On Nature’s blog Emma Morris report’s on his talk From the bright green soy field to the rolling blacktop…this land was made for you and me:

What is the typical landscape of the United States? Jeffrey Cardille, of the University of Montreal wondered the same thing. He may be in Montreal now, but he’s from the US of A, and a big Woody Guthrie fan. Guthrie, in his alternative national anthem “This Land is Your Land” invoked the “redwood forests,” the “gulf stream waters” and so on. But could it be that the archetypal US landscape these days is rather a cornfield or a brand new subdivision?

To find out, Cardille used an algorithm called “affinity propagation”, made famous in this Science paper by Frey and Dueck. As Cardille explains, the algorithm is “a way to find representative samples in complex datasets.” In the Science paper, it was used to create clusters of faces the same people out of a sea of photographs. Each cluster was organized around a central exemplar photo.

Cardille used the same method on landscape data from the National Land Cover Data Set, and metrics extracted from the dataset with a program called fragstats. He gridded the lower 48 off into 6 km by 6 km squares and then let the algorithm rip on the data—5% at a time due to computing power limitations.

What emerges on any one of the runs are something like 17 exemplar squares, real chunks of the landscape that best represent the totality of the landscape. Predictably, of the 17 in the run he presented, 13 are human dominated—row crops, clear cuts, urbanizing suburban land, and the like. Two are carefully managed national parks. Just two are more or less running themselves. One of these is a square of the vast shrub-lands of Texas.

General

Short Links: Gorillas, drunky shrews, and jellyfish

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Three nature stories from the New York Times:

In the Congo Republic a survey has discovered a large population (125 000) of Western lowland gorillas.

Trove of Endangered Gorillas Found in Africa

The survey was conducted by the Wildlife Conservation Society and local researchers in largely unstudied terrain, including a swampy region nicknamed the “green abyss” by the first biologists to cross it. Dr. Steven E. Sanderson, the president of the society, marveled at the scope of what the survey revealed. “The message from our community is so often one of despair,” he said. “While we don’t want to relax our concern, it’s just great to discover that these animals are doing well.”

It’s Always Happy Hour for Several Species in Malaysian Rain Forest

German scientists have discovered that seven species of small mammals in the rain forests of western Malaysia drink fermented palm nectar on a regular basis. For several of the species, including the pen-tailed tree shrew, the nectar, which can have an alcohol content approaching that of beer, is the major food source — meaning they are chronic drinkers.

Oceanic food webs shifting to dominance by jellyfish, due to overfishing of top predators, and likely coastal eutrophication and climate change.

Stinging Tentacles Offer Hint of Oceans’ Decline

From Spain to New York, to Australia, Japan and Hawaii, jellyfish are becoming more numerous and more widespread, and they are showing up in places where they have rarely been seen before, scientists say. The faceless marauders are stinging children blithely bathing on summer vacations, forcing beaches to close and clogging fishing nets.

But while jellyfish invasions are a nuisance to tourists and a hardship to fishermen, for scientists they are a source of more profound alarm, a signal of the declining health of the world’s oceans.

“These jellyfish near shore are a message the sea is sending us saying, ‘Look how badly you are treating me,’ ” said Dr. Josep-María Gili, a leading jellyfish expert, who has studied them at the Institute of Marine Sciences of the Spanish National Research Council in Barcelona for more than 20 years.

Adaptation

Language and Evolution: Frequency selection and Bursts

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John Whitfield has an interesting review article Across the Curious Parallel of Language and Species Evolution in PLoS Biology (PLoS Biol 6(7): e186) on language and species evolution.

One parallel between living things and languages is that their most important components show the least variation. In biology, this means that genes such as those involved in the machinery of protein synthesis change so slowly that they can be used to discern the relationships of groups that diverged hundreds of millions of years ago. Likewise, the most commonly used words, such as numbers and pronouns, change the most slowly. Looking at 200 of the commonest words in 87 Indo-European languages, Pagel’s team found that the frequency with which they are used in everyday speech explains 50% of the variation in the rate of word change [4]. Similarly, Erez Lieberman, an evolutionary theorist at Harvard University, and his colleagues have found that over the past millennium, English verbs have become regularized at a rate inversely proportional to their frequency [5]. The frequency effect means that some rates of lexical replacement are comparable to the evolutionary rates of some genes, says Pagel; he thinks that these words might allow researchers to build family trees showing the relationships between languages reaching back 20 millennia, compared with the 8,000 years or so that most linguists currently think possible.

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Earlier this year, Pagel and his colleagues uncovered another parallel between linguistic and biological change. Languages, they found, change slowly for a long time, and then undergo a sudden burst of change [6]—what biologists call punctuated equilibrium. These bursts seem to coincide with periods of linguistic speciation, when populations split and their languages diverge. Looking at trees of Indo-European, Austronesian, and Bantu languages, the researchers found that those languages that had gone through the most splits had changed more, with up to a third of changes being associated with split points. Pagel suggests that languages change when populations split because groups consciously or unconsciously use how they talk to define themselves and separate insiders from outsiders—as in the Old Testament book of Judges, when the men of Gilead identify their Ephraimite foes by their inability to pronounce the Hebrew word for an ear of grain, shibboleth, now a general term for a linguistic password.

Ecosystem services, Millennium Ecosystem Assessment

Crop per Drop vs. Water for Ecosystem Services

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Colin Chartres the International Water Management Institute‘s director general writes Invest in water for farming, or the world will go hungry.  In SciDev.net he writes:

The world’s population is projected to grow from 6 billion to 8.5 billion by 2030 and unless we change the way we use water and increase water productivity — ie. produce more ‘crop per drop’ — we will not be able to feed them. That is the conclusion of the IWMI’s recent Comprehensive Assessment of Water Management in Agriculture and its book, Water for Food, Water for Life, which drew on the work of 700 scientists.

While I agree that increasing agricultural water productivity is important, I think an underappreciated message of the CA (which is available online) is that globally we need to increase ecological water productivity.

A focus solely on agricultural production is likely to continue to cause declines in other valuable ecosystem services, sometimes to the extent that they outweigh any benefits gained from increases in agricultural production (See Millennium Ecosystem Assessment for many examples).  Agriculture provides benefits, but it also imposes costs.  Agriculture that ignores its ecological context has lead to coastal hypoxia, dryland salinization, and land degradation.  These problems reduce other ecosystems services, such as fisheries, while also decreasing the ecosystem support for agriculture.  These problems are increasing and overall are expected to worsen due to climate and other human caused global environmental change.

The quality, quantity and reliability of water flows connect agricultural and non-agricultural ecosystems. Water is also essential to the production of agricultural and most non-agricultural ecosystem services. Where these connections are strong requires an integrated approach to the management of water across landscapes and regions to ensure the reliable production of multiple ecosystem services.  However, in many cases we currently lack the practical knowledge to effectively manage agricultural and non-agricultural ecosystems for the multiple ecosystem services that depend upon water.  This research area is relatively underdeveloped and it is critical for ensuring human well-being in an increasingly unpredictable and resource intensive world.