Plant & Animal Ecology

Publication Analysis 2007-2013
by Kathleen Gransalke, Labtimes 06/2015

View the Tables: Europe...and the World, Most Cited Authors...and Papers

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Image: Michael Siva-Jothy/Sheffield University, CC-BY 2.0

Young and wild, this discipline jumbles up the traditional nations’ ranking order. Ecosystem response to global change and biogeochemistry are just two of many different research specialities.

In our last issue, we chose the winning and a “highly commended” image of the 2015 BMC Ecology Image Competition to be our Picture of the Issue. Ecologists, as we have learnt, view nature and the world with very different eyes. Thus, who could better describe this research discipline than ecologists themselves? “‘Ecology’ derives from the Greek word for ‘house’. Across the four oceans and seven continents, ecologists study the wondrous organisms, interactions and locations that, combined, make up our own house, the planet Earth. Whether cataloguing biodiversity, describing a new species interaction or modelling migratory patterns, ecologists contribute to our understanding of the world and our place in it,” write amongst others Michel Baguette (Natural History Museum, Paris) and Josef Settele (Helmholtz Centre for Environmental Research, Leipzig) in the editorial, announcing the winners of the image competition.

From this description, it’s clear that ecology, as a research discipline, is not as limited as one, at first, might assume. In actual fact, it is the “most comprehensive and diverse of the sciences. Its scope is enormous and it may be the most important science for managing the earth as an abode for humanity and for what is left of our natural environment”, notes ecologist and science historian, Frank Egerton, in an article series about the history of ecology for the Bulletin of the Ecological Society of America.

A young discipline

Despite its obvious importance today, the discipline is relatively young. Aristotle and his student Theophrastus may often be credited as the “first ecologists” but it was German zoologist Ernst Haeckel, in the 19th century, who came up with a name for the new research speciality (“Öecologie”) and a definition (“study of the relationship of organisms with their environment”). It took a few more years, still, before the “new science” became properly organised, with the first national ecological organisation opening its doors in Great Britain only in 1913.

Let’s stick with history for a while and look back to our first Plant & Animal Ecology publication analysis, covering research output (articles, reviews and proceedings papers) from European ecologists between 1996 and 2007 (LT 6-2009). Six years ago, England was the yardstick for all things: English ecologists collected twice as many citations as their French and German peers, three of the five most-cited papers had a corresponding address in England and 12 of the 30 most-cited authors were affiliated with an English University or Institute.

So, what’s hot and what’s not in ecology, in 2015? Let’s find out! First, by looking at the nations’ performance. For this part of the analysis, we solely relied on the so-called ecology expert journals, as defined by Thomson Reuters’ Web of Science database. England still produced the most articles (8,174), gathering the most citations (181,854) but it lost some of its dominance. German (7,418 and 143,976) and French (6,243 and 129,059) ecologists are closing in, inexorably. Interestingly, compared to most biomedical disciplines, the ‘traditional’ nations’ ranking order has had a serious shake-up. For instance, Italy, regularly in the top 5, came in only in 9th position. Also Austria’s (15th) and Israel’s (20th) research focus appears to lie somewhere other than in ecology. In contrast, North European countries did much better than usual. With Sweden (7th) and Finland (10th), two Lands of the North managed to snatch a spot in the top 10.

On average, an ecologically-themed article or review is cited about 20 times. Topping this list is Switzerland with 25.6 citations per article, followed by an unlikely candidate, Estonia (23.8). The Baltic country, 22nd according to number of citations, owes this good position partly to an ecologist from Tartu, who even made it to our top 30 most-cited ecologists in Europe. Globally, European ecologists wrote more articles and gained more total citations, but broken down to average citations per article, US ecologists are still one tiny step ahead (16.7 vs 17.5). Also Canadian, Australian and New Zealand ecologists can pride themselves on their research output, they even got ahead of research heavyweight Japan.

Now let’s get back to European ecologists and their most-cited papers. Six years ago, the majority of ecology’s top papers had reprint addresses in England. Our 2015 publication analysis, however, revealed that, these days, highly-cited articles and reviews are not only written in England but also in Sweden, The Netherlands and, especially, Germany. The Swedish and Dutch articles (1st, 4th), both co-authored by Marten Scheffer (5th), deal with ecology in a bigger context. “A Safe Operating Space for Humanity” looks at the effects human activities could have on the Earth’s complex systems, such as the monsoon system, which, if it changes, can have “deleterious or potentially even disastrous consequences for humans”. Likewise, “Early-warning Signals for Critical Transitions” describes ecosystems as a model for complex dynamical systems, suitable to predict critical tipping points. The other three most-cited papers are more typical of pure ecology, reporting findings in crop ecology (2nd), a new method to analyse species distribution data (3rd) and changes in CO2 uptake by carbon sinks on land and in the oceans (5th).

Are there any preferred habitats for highly-cited ecologists in Europe? Their distribution is wide, ranging from Northern Europe (Sweden, Norway, Estonia) to the South (Spain); from the British Isles to the Czech Republic. Higher population densities can, however, be found around Grenoble, Wageningen, Jena and Leeds. Astonishingly, there’s only one female ecologist among our top 30. Sandra Lavorel (23rd) specialises in functional ecology. In her Alpine Ecology lab in Grenoble, she studies “plant functional trait responses to environment and impacts on ecosystem functioning”.

One of Lavorel’s colleagues in Grenoble is Wilfried Thuiller, who claimed the top spot in our ecology ranking, with 8,001 citations. With the support of an ERC Starting Grant, he currently develops eco-evolutionary models for biodiversity scenarios. One of the questions, the TEEMBIO project members want to answer is how evolution shapes species niches and ranges.

Besides biodiversity and conservation, another hot topic is, unsurprisingly, the effect of global change on ecosystems. Ecosystems, thus, have to cope with a multitude of potentially disruptive factors – the changing climate (Araujo, 4th; Stenseth, 20th), biological invasions (Pysek, 8th; Kühn, 13th), or natural or man-made disasters like the Chernobyl nuclear accident (Møller, 28th). All of these factors affect species distribution (Guisan, 10th; Niinemets, 27th) and biodiversity (Steffan-Dewenter, 18th). Also, urban life takes its toll on wild animals and plants (Gaston, 7th). Night-time light pollution, for instance, could mess up organisms’ biological clocks, with negative consequences for their growth, behaviour and reproduction.

From ecosystems to the atmosphere and back

A big portion of our top 30 most-cited ecologists in Europe are interested in biogeochemistry, a branch of ecology, exploring the cycling of carbon, water, nitrogen, phosphorus or trace gases between terrestrial or aquatic ecosystems and the atmosphere (­Reichstein, 2nd; Prentice, 12th; Sutton, 26th). Understanding the carbon cycle has become a major concern for scientists, not only because carbon is the main component of all organic molecules on earth but also because human activities (burning of fossil fuels, deforestation) actively interfere with this natural cycle. But there’s hope. Tropical trees absorb about 18% of the CO2 added to the atmosphere each year from burning fossil fuels. And some recent studies suggest that tropical rainforest trees get bigger and hence, store more carbon (Nature, 457, 1003-6). Forest ecology and/or the carbon cycle are also David Wardle’s (11th), Yadvinder Malhi’s (15th), Oliver Phillips (21st) and Johannes Cornelissen’s (30th) favourite research subject.

Two more ecology research flavours remain: agroecology and chemical ecology. Studying food crops, Teja Tscharntke (6th), who co-authored the second most-cited paper in ecology, revealed that the majority of global food crops depends on animal pollination. And Ian Baldwin (16th) and Marcel Dicke (29th) eavesdrop on the chemical communication between plants and herbivores.

Being a young and unjaded discipline, there’s a lot we can still expect of ecology. Especially considering the fact that man-made global changes are just starting to catch up with us.

View the Tables: Europe...and the World, Most Cited Authors...and Papers

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Last Changed: 22.11.2015