The Quest for Predicting Plant-Soil Feedback

A new study from the Department of Soil Quality at Wageningen University and the Department of Terrestrial Ecology at Netherlands Institute of Ecology (NIOO-KNAW) gives evidence that plants grow better in soil from other species. Published today in Journal of Ecology, the paper is written by Cortois et al. and is titled; Plant-soil feedbacks: role of plant functional group and plant traits. 

Authors Roeland Cortois and Gerlinde De Deyn have described below their inspiration behind the study and the significance of their work in the understanding of plant-soil feedbacks and their role in plant communities.


It all started with a simple question which we asked ourselves several years ago: can plant-soil feedbacks explain overyielding in plant species rich communities? 

First of all we aimed to figure out whether plant-soil feedback (PSF) is actually occurring at a measurable and relevant scale and whether feedback sign (positive, neutral or negative) and strength are predictable from plant traits. Considering the growth versus defense trade-off hypothesis, we expected plant species with more acquisitive traits to build-up more negative feedback, whereas species with conservative traits would build-up more positive feedback with their own soil biota.

We formed a strong team, with a fine combination of Dutch and Flemish researchers specializing in plant-soil feedback, and German collaborators with expertise on plant traits. With a species pool of 60, The Jena Biodiversity Experiment provided a very nice experimental setting to test our ideas, but imagine what this number of species meant for testing plant-soil feedbacks and quantifying above-ground and below-ground plant traits…

Roeland collecting Jena field soil which we used to let the plants culture their own microbes and test the feedback responses against a ‘neutral’ control.

Roeland collecting Jena field soil which the plants used to culture their own microbes and test the feedback responses against a ‘neutral’ control.

For 48 focal plant species, we tested growth responses i) in their own soil, ii) in a neutral living soil (mixture of soil from all plant species), and iii) in a sterilized soil inoculum. Sounds easy, but the crux of the matter is how to choose experimental soils and how to interpret the results ecologically. We pondered about this for some time.

In the current study we decided to determine two important aspects of PSF-dynamics: the net effects of soil biota on plant growth and the potential of a plant species to escape (or lose) its own soil feedback by growing in other species’ soil, which turned out to benefit most species. This has led to novel insights on both intra- and interspecific variability of plant-soil feedbacks. We found that graminoids and small herbs built up a net negative relationship with their own soil biota: they grew better in sterilized soil than in living soil. Legumes responded on average neutrally, while tall herbs seemed to harness more benefits than detrimental soil organisms: they mostly grew better in living soil than in sterilized soil.

Interestingly, most species grew better in neutral living soil compared to their own soil, irrespective of functional group. These findings may suggest that pathogens exhibit relatively strong host species-specificity while mutualists are more generalized. It is also possible that the herbs benefitted more from mutualists of other plants than of their own (Bever, 2002).

Left: One replicate block of the feedback experiment (red labels: living own soil; yellow labels: living all species soil; white labels: sterilized soil). Right: Two times the same plant species (Sanguisorba officinalis) planted at seedling stage but growing very differently in response to the soil treatments.

Left: One replicate block of the feedback experiment. Right: Sanguisorba officinalis planted at seedling stage but growing very differently in response to the soil treatments.

All together interesting findings, but we were not satisfied yet. The next step was to use plant traits to plant functional groups in order to predict the variation of plant-soil feedback. Our findings showed that plants with negative plant-soil feedback had on average thin roots and few arbuscular mycorrhizal fungi (AMF) in their roots, while positive plant-soil feedback plants had on average thick roots and were more colonized by AMF. This provides new evidence for the idea that ‘fast’ plants are vulnerable to detrimental soil factors, while ‘slow’ plants interact more positively with below-ground biota.

How do our findings add to our understanding of plant-soil feedbacks and their role in plant communities?

Firstly, we have provided increased predictability of plant-soil feedbacks by plant traits, which is useful for further integration of plant-soil feedback concepts in plant ecological strategy frameworks – in which plant trait analyses are an essential tool. Secondly, we found that plant functional group identity was also an important predictor of plant-soil feedback, and we showed that large forbs not only depend strongly on their own beneficial soil biota, but they benefit even more from biota in soils of other species. This latter observation makes it likely that plant species with a positive feedback from soil biota contribute more to plant productivity in mixtures than plants with negative feedback. In that sense, we also provide some understanding for the often supposed importance of plants with negative plant-soil feedback in causing higher productivity in increasingly diverse plant communities. Of course, these plants benefit from growing in soil of other species, but as the tall herbs with a positive feedback benefit as well, the net result may be that the positive plant-soil feedback plants dominate the diversity-productivity effect after all.

Turning back to the relationship between plant-soil feedbacks and the framework of fast-slow resource strategies of plants, we think that the coupling of functional traits and plant-soil feedback is a great way to integrate plant-soil feedback research in the study of plant ecological strategies. In a coexisting species pool of plants, species show trade-offs in dispersal, growth rate, defense against natural enemies, competitiveness etc., which allows us to not only analyze and understand their coexistence, but also to understand the dynamics of plant communities, spatially and temporally. The relevance of plant-soil feedback for a plants’ ecology only becomes clear when integrated with other aspects of its ecology. Our study lays important ground for this challenging quest.

Roeland Cortois & Gerlinde De Deyn
Wageningen University & Netherlands Institute of Ecology (NIOO-KNAW)
The Netherlands

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EDIT: you can read the press release from (NIOO-KNAW) here.

Volume 104, Issue 5

The September issue of Journal of Ecology is now online!

Volume 104, Issue 5

September 2016: Volume 104, Issue 5

This issue includes a Special Feature edited by Wayne Dawson and Maarten Schrama titled; Digging Deeper: How soil biota drive and respond to plant invasions. The Special Feature brings together current research on soil microbes as drivers and responders of invasion, highlighting the methods that can be used to advance our understanding of how, when and which soil microbes play a role in the invasion process. The collection comprises of 6 research articles as well as an editorial from the guest editors. All the papers are currently free to access here

Other papers featured in this issue include an interesting study by Kramer-Walter et al. which compares leaf, stem and root functional traits of some common woody species native to New Zealand, as well as a commentary on the same paper by Oscar Valverde-Barrantes and Christopher Blackwood. There is also a study on plant diversity and functional trait composition by Timo Conradi and Johannes Kollmann which evaluates the drivers of community structure of recovering calcareous grasslands. Further contributions include a paper from McIntire et al. on factors limiting tree line seedling abundance, a study about two invasive Australian acacias from Correia et al., and a study by Avila et al. on Quercus suber dieback. There are also two Open Access papers in this issue, including a plant mutualism study from Shelby et al. and a paper on the effect of drought periods from Fuchslueger et al.

The cover image for the September issue was provided by Duane Peltzer, one of the co-authors of the Gundale et al. Special Feature paper on plant interactions with fungi. The photo shows the invasion of the North American Lodgepole pine in New Zealand into an area previously dominated by a Southern Hemisphere beech species, as shown in the forest in the background.

James Ross
Assistant Editor, Journal of Ecology

Some ESA 2016 afterthoughts on the Era of the Anthropocene, Population Ecology, and Archbold by Rob Salguero-Gómez

The annual meeting of the Ecological Society of America took place a bit over a week ago (Aug 7-12th 2016) in Fort Lauderdale. ESA + Florida + August + no hurricanes in Florida the last 10 years = get ready to get blown away either by an overdue hurricane or by the great science that is typically presented at the ESA. Thanks to the fact that a hurricane last week decided last minute to divert its trajectory away from Ft Lauderdale, we were only blown away by the science… ok, and by a lot of humidity too.

The theme of this year’s conference was “Novel Ecosystems in the Anthropocene”, continuing the legacy that was set at the centennial meeting last year in Baltimore. Ecology has the challenging responsibility of understanding and producing predictions regarding how ecological systems will respond to various interacting drivers, both biotic and abiotic. The emphasis in the last decades has turned to treating humans as a third axes of effects. Along that line of thought, the 2016 meeting was full of keynote talks and symposia that nicely summarized our current understanding of human effects on ecosystems and set goals and directions for our futures research steps. I have followed the work by Jeannine Cavender-Bares for a while now (who hasn’t right?), and I thoroughly enjoyed her New Phytologist lecture “Evolutionary legacies on ecosystems: implications for managing planet Earth in the Anthropocene”.

ESA was full of excellent talks on population ecology – too many to choose!*. Population ecology constitutes one (of many, not just the one) discipline to address effects of abiotic/biotic factors and human influences on ecological systems due to the quality of the demographic data that are being collected by researchers around the globe, as well as the robust methodologies that have been developed to analyse such data. One year again, I was very happy to see this discipline going very strong. My favourite talk by an early career ecologist was the one given by Britta Teller “Do small and large plants respond differently to climate variation?”. In it, Britta used splines to model the asymmetric effects of lag effects of climate and neighbouring onto various shrub species in the US Midwest. An important contribution of this modelling approach is that it allows one to decompose past weather effects onto the vital rates of survival, growth and reproduction in a way that they do not cancel each other out (if say 2012 was 2.5 cm precipitation below average, but 2012 was exactly 2.5 cm above average)… as I **might** have done in the past myself. Her approach, using Integral Projection Models, allowed her to examine how abiotic/biotic variables differed in their effects to the same plant species as a function of individual size. I’m very excited to see this methodology been applied to more species, as I reckon that size redistributions are rather common in populations of modular organisms, yet not a well understood phenomenon in plants, particularly in aridlands. My favourite talk by a perhaps-not-so-early career ecologist was the one given by Robert Holt “On the interplay of demographic stochasticity, fitness, and the niche concept”. In it, Holt formalized the link between the Hutchinsonian niche and two key demographic properties: the intrinsic rate of growth of a population (r), and the number of offspring produced in an individual’s lifetime (Ro). Holt showed that in stochastic environments, r and Ro can be optimized differently, producing selection gradients that would push populations towards different local maxima. I particularly enjoy the simplicity with which he presented abstract concepts, and how the talk explicitly linked theory with ecological applications like habitat degradation, or range margin vs. center dynamics.

*And as it usually happens at the ecological monster that it is ESA, it was impossible for me to go to all talks that I would have liked. Here’s a list of the things that looked very promising on the ESA program: 

  • Matthew Tye et al. Demographic responses to climate change in boreal orchids: Effects of local habitat heterogeneity and life history variation.
  • John Gatto et al. – Using Virtual Population Analysis (VPA) to estimate under-sampled recruits to improve population dynamics models.
  • Andrew Tredennick et al. – Disentangling the drivers of species synchrony in natural plant communities: Environmental forcing, demographic stochasticity, and interspecific interactions.
  • Robert Shriver – Bridging the gap between physiology and demography to understand climate change responses of a desert annual plant community.

There was also a lot of demography being discussed at the organized oral session “Landscape Demography: Heterogeneity Across Space and Scale”. I particularly enjoyed the talk by Pedro Quintana-Ascencio, Stephanie Koontz, Stacy Smith, Vivienne Sclater & Eric Menges entitled “Predicting landscape-level distributions: Integrating demography, fire, and dryness with patch and annual variation”. These guys have been collecting high-resolution demographic data on a series of endemic plant species of the Florida Scrub at Archbold Biological Station. Pedro reviewed some of the complications in the analyses of these data, and how interactions of various biotic and abiotic factors, especially time since fire, shape the responses of multiple sites within multiple populations of the target Hypericum cumulicola using Bayesian IPMs. On that note, we recently also published in Journal of Ecology a demographic menage-a-trois on one of this demographic jewels of plant population ecological studies (Liatris ohlingerae) that may be of interest (Tye et al. 2016). We’ve been working on this species for a few years now, but only this week, did I get to meet it in person!

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Left to right: Rob Salguero-Gómez, Eric Menges, Betsy Hermanson Boughton and Pedro Quintana-Ascencio

I would also like to talk about the wonderful job that Archbold Biological Station has been doing for population ecology. One of the limitations of plant and animal comparative demography is the fact that most studies only examine population dynamics of the target species in one site. We know that intra-specific variation across sites/populations exist… but exactly how much, how important is it, and how can it be predicted? Eric Menges, leading the plant ecology lab at Archbold, has now for over 30 years been collecting high-quality demographic information of multiple endemic species across the 3577 hectares of Archbold. Only the involvement of dozens of interns, volunteers, researchers and staff, and the clear leadership of the Station can make such a titanic effort possible. Given their scientific and outreach impact, it is perhaps not by coincidence that this year the ESA decided to donate the carbon print offsets related to our little ecological reunion in Fort Lauderdale to them.

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Acknowledgement slide of Pedro Quintana-Ascencio & Eric Menges on the number of people involved in the study of 22 sites and < 18,000 individuals of Hypericum cumulicola in Archbold Biological Station

The Associate Editors of Journal of Ecology present at the conference had a business meeting followed by a dinner (see photographic evidence below of how badly they treat us, poor editors). Turns out the journal is doing very well, with a brand new impact factor of 6.18, and that some of the works that my colleagues have been involved in lately has been rather impactful. For instance, the Special Feature “Demography beyond the Population”, the first one in its nature in that it spanned all journals of the BES, had an impressive number of downloads. Also some of these papers were presented at the ESA, such as Martina Treurnicht et al. “Environmental drivers of demographic variation across the global geographical range of 26 plant species” (Treurnicht et al. 2016), and Jessica Needham, et al.A “A distributional approach to modelling the population dynamics of forest trees” (Needham et al. 2016). Also, side note to say congratulations to special feature contributor Jenni McDonald for her recent ESA Plant Population Ecology Section Postdoctoral Award on her paper (McDonald et al. 2016) – see also Jenni’s blog post here.

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Left: a poor Associate Editor (Rob Salguero-Gómez) suffering a post-business meeting of Journal of Ecology. Right: all other poor Editors, from left to right, Rob Salguero-Gómez, David Gibson, Emilie Aimé, Hans Cornelissen, Yvonne Buckley, Nina Wurzburger, Nicole Rafferty, Sunny Power, Catherine Hill & Frank Gilliam.

Next year the ESA takes place in Portland, and I’m already looking forward to it. Some colleagues and I are planning on running workshops on IPMpack as well as on COMPADRE & COMADRE, and to put in a proposal for a symposium at the interface of functional traits and life history traits, so stay tuned!

Rob Salguero-Gómez
Associate Editor, Journal of Ecology

PS: and here are some humble, personal requests to the ESA:

twi1. I think that it is a bit strange that the default option for talks at ESA is for researchers to not be able to tweet about the science being presented… I operate on the assumption that if you  choose to present at a conference it is for the science to be discussed in an open forum. As I suggested last year, I think that the default option should be “Feel free to tweet”, and perhaps create a logo to be added to the top-right corner of each slide where the speaker does not want the audience to tweet about?

2. I look forward to Portland… ESA there in 2012 was great fun (and excellent beers and post ESA hiking!)… but can we come back to Baltimore soon so we overlap with Bronycon again? Wasn’t ESA 2015 a lot more colorful because of our friends the bronies?

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A bit of memory: a brony at last year’s ESA.

Reflecting on ESA2016 ‘Novel Ecosystems in the Anthropocene’: Three Ecologists Provide Contrasting Perspectives.

Traveling back from the 2016 Annual Meeting of the Ecological Society of America, I was struck by how well the meeting theme ‘Novel Ecosystems in the Anthropocene’ resonated through the presentations (a second theme was seafood – see below). Not all, but a large number of organized sessions and symposia were organized around the meeting theme such as ‘Rising Novelty in Ecosystems and Climates: Looking to the Past to Understand a No-Analog Future’, ‘Novel Ecosystems and Adaptive Management: Sustainability in the Anthropocene’, and ‘Ecological Novelty in the Anthropocene: Are Novel Communities Novel Ecosystems?’.  I didn’t get to most of these, and my own presentation on weed seedling emergence was clearly off-topic, but the social media buzz was all about the theme. All of this sharpened my thinking and awareness of the topic, and, as I listened to presentations, it became clear that while a full understanding and appreciation of the theme among ecologists is emerging, a consensus on how we can apply knowledge from studying and characterizing modern and past ‘novel ecosystems’ is still unclear. Are novel ecosystems systems unique (i.e., ‘no-analog’) only to the recent human-characterized past (i.e., the Anthropocene), or must they have never existed in the deeper past? Do we characterize novel ecosystems by their species assemblage, functional traits, or ecosystem services (or some combination)? Do we manage for novel ecosystems, or are we to accept that they are characteristic of the current biosphere that we have to ‘live with’?

Here we present interviews with three ecologists that I ran into at ESA. All are Journal of Ecology Associate Editors so each has a good sense for some of the best research being conducted and published. Charlie Canham and Emily Farrer are also co-authors on a couple of the papers that the British Ecological Society included in a Virtual Issue made available to celebrate the ESA meeting theme. I asked the same set of questions to each, albeit with unique follow-ups, but, as you’ll hear, heard a distinctly different, but informed, take. Clearly, the meeting theme is important and relevant, and it’s very interesting to learn how different ecologists view it.

 

Interview with Charlie Canham

 

Interview with Jacquelyn Gill

 

Interview with Emily Farrer

 

Now, about that seafood theme:

EmilyA

JEcol Managing Editor Emilie Aimé tackles crab legs

David Gibson
Executive Editor, Journal of Ecology

Winner of the Postdoctoral Excellence Award – ESA Plant Population Ecology

Editor’s note

We are very pleased to announce that Jenni McDonald has been selected to receive the Postdoctoral Excellence Award by the Ecological Society of America’s Plant Population Ecology section for her Journal of Ecology paper, “Transients drive the demographic dynamics of plant populations in variable environments.” This paper was part of a BES cross-journal Special Feature “Demography Beyond the Population” comprising 21 papers on this important topic. Congratulations Jenni!

David Gibson
Executive Editor, Journal of Ecology


Jenni.pngJenni McDonald is an early career researcher currently two years into her first postdoctoral research position at the University of Exeter. Her research applies comparative demographic approaches to explore the evolution of life histories. Using COMPADRE, a global database of plant demographic models, coupled with simulated life histories, she is exploring the demographic buffering hypothesis, a theory that predicts traits that have a large influence on fitness are stabilized against environmental change by buffering that trait. Her exploration of stochastic population dynamics in combination with the strong transient research background of colleagues (past and present) at the University of Exeter led to the research topic of the paper published in Journal of Ecology, which highlights the importance of transients in variable environments.


Transients in variable environments

The natural world is rarely constant. Consequently, studying the dynamics of wild plant populations in variable environments is of particular significance to ecologists seeking to understand life history evolution, and has major implications for management and conservation. 

Until recently, two major types of analysis have explored this environmental variability. First, stochastic analysis, which accounts for variation in vital rates with survival, growth and reproduction changing over time. Second, transient analysis has shown that a population’s response to changing environments depends on the population stage structure, i.e. the number of individuals occupying each (st)age class. For example, a greater number of reproductive individuals will result in accelerated population growth (boom), whereas a bias towards immature individuals will reduce expected population growth (bust). Ellis and Crone (2013) highlighted that these two key processes are not mutually exclusive. Both an individuals’ vital rates (survival, reproduction, growth, regression) and population responses to shifts in demographic structures ((st)age structures) contribute to stochastic population dynamics.

The contribution of differences in vital rates alone can be measured by the asymptotic rate of growth or decline of the population. This pivots on the assumption of equilibrium dynamics, where the asymptotic growth rate and associated stable stage structure is assumed to be constant over time. Transient indices account for departures away from a stable population structure in non-stationary environments and quantify the instantaneous boom/bust in each time-step.

Our study, published in Journal of Ecology, builds on this research to disentangle the absolute and net contribution of transients to the population dynamics of 277 plant populations, comprised of 132 species from the COMPADRE database. We tackle the question, “what is the relative contribution of transient boom and bust to the dynamics of plant populations in variable environments?”

Using a simulation approach, we decompose the dynamics of each time step in to asymptotics and transients, with our results highlighting that transients contribute to over half the dynamics in stochastic environments. This result was true for net dynamics as well as absolute dynamics, which accounts for the strength of opposing asymptotic and transient effects, emphasising the important role transients play in shaping the population trajectories of plants.

This analysis raises several potential hypotheses for further exploration. First, the number of life stages modelled influenced both the contribution of transients and asymptotics. Whether this is a consequence of life history complexity or an artefact of modelling design remains to be explored. We also found plant populations tended to boom in response to temporal changes. Is an ability to bounce back from disturbance an adaptive response to living in a variable world?

Our results emphasise the embedded nature of transients in stochastic population dynamics and reveal interesting evolutionary and methodological patterns. These findings, along with continued methodological advances in the study of transients, will prompt further comparative analysis of transient population dynamics and increase the practical utility of these methods for management and conservation.

Jenni McDonald
University of Exeter
United Kingdom

Harper Review 2016 – meet the author

This year wHarper review covere published the first of our annual Harper Review series. The series is named after past BES President and Journal of Ecology Editorial Board member, the late John L. Harper CBE FRS and is designed to be thought provoking, authoritative and of broad interest to the ecological community.

Our inaugural review was written by Yvonne Buckley from Trinity College, Dublin and Jane Catford from the University of Southampton and is titled  Does the biogeographic origin of species matter? Ecological effects of native and non-native species and the use of origin to guide management.

We asked Yvonne, who is one of journal’s Associate Editors, to tell us a bit about the review and her research.

        How did you feel about being asked to write our first Harper Review?

Reading Harper’s book “Population Biology of Plants” as an undergraduate sparked my interest in population ecology so it was a real honour to be asked to write the inaugural Harper Review for Journal of Ecology. I had been thinking about writing that paper some time ago but other projects kept getting in the way, the review deadline was great motivation to finally sit down and write it! My co-author Jane Catford and I had been working on a paper on the different demographic dimensions of species invasiveness (also recently published in Journal of Ecology) so we decided to work on the Harper review together as well.

        What’s the focus of your research?

Population ecology at large spatial scales has always been central to my research. I’m particularly interested in performance of populations in new ecological contexts and variation in population performance within a species. Population performance sits between individual level traits and the persistence or extinction of species so an understanding of the links from traits and physiology through to populations can help with integration of understanding across these scales.

        Can you give a brief summary of the paper in layman’s terms?

When populations of plants are moved to areas where they have never occurred before, they can become weedy and cause economic, social & environmental problems. There are some unresolved questions about plant invasions: Do these plants become more numerous in their new environment or are they in similar numbers in their home environment? Is the ecology of plants in new environments predictably different from the ecology of the native plants? We use recent global studies to show that while plants perform similarly well at “home” as “away”, non-natives do particularly well in fertilized conditions, whereas native species are often lost. We can therefore use the information about a species origin (native or non-native) to make ecological predictions. We argue that a likely explanation of the differences in ecology of natives & non-natives is the biased selection of species that humans move around. Species living close to humans and our industries are more likely to be transported and to do well in the human modified environments we introduce them to. This direct inclusion of humans into our understanding of the ecology of the system is absolutely necessary for understanding the problem and development of solutions. Humans don’t sit outside of “ecology” we are a driving force shaping species distributions & abundances.

        Why is research into invasive species so important?

Individual invasive species are economically & environmentally damaging so there is strong motivation to understand & solve those problems. The more general issue  however, is of understanding the massive species redistributions we are seeing now. What will the ecosystems of the future look like? How will they function? How will ecosystem services change? Non-native species have been introduced to many different environments & can also give us insights into the responses of species to climate change.

        What additional research questions arise from your Harper Review?

There are many! I’m currently working on the population ecology of ribwort plantain Plantago lanceolata, one of the commonest & most widespread species in the world to understand how it copes with environments as different as the sub-Arctic to the sun-tropics. It has been introduced outside of Europe & has a close commensal relationship with humans & our habitats. I am interested in how populations persist through growth, survival and reproduction processes in these very different environments and whether plant traits can be linked with demography. In order to look at large scale processes population ecologists need to work together and I am a fan of the coordinated distributed network approach which has worked so well for other projects like NutNet which I’ve worked with for the last 9 years or so. PLANTPOPNET is a network of researchers recording population processes for Plantago lanceolata all over the world – we already have data from 31 sites from Europe, North America and Australasia and we’re continuing to expand. The whole area of human ecology, treating humans as an interacting species rather than just observers, needs to be better developed.

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Yvonne at her PLANTPOPNET site in Coolclogh, Ireland.

        What are the key messages for managers?

Managers often have to work with limited information on the composition and ecological function of species in the communities they are managing. The studies referred to in the Harper Review indicate that for grasslands at least non-native species are likely to be more abundant and dominate communities than natives and non-native species (unlike natives) do not decline with fertilisation. These predictable aspects of introduced species arise not because they have changed their ecology outside their native range but because we tend to introduce species with these characteristics. In the absence of site specific data managers can therefore use information about a species from its native range to predict aspects of its ecology in its non-native range.

        How can policy makers help with these issues?

This work shows that understanding the introduction process and managing species introductions would be particularly helpful in preventing unwanted effects of non-native species. We need more research on invasion pathways and the types of species likely to be introduced through those routes in order to prioritise pre-border efforts on pathways (dispersal vectors) likely to bring in the most damaging species.

        When you’re not at work what do you like doing?

I hang out with my kids (6 and 4). I was having a go at hurling with them the other evening after getting in from a day in the field, it’s an Irish team sport which uses a wooden stick (a hurley) to hit a ball into the opposition team’s goal. If all of that sounds too wholesome rest assured that when they went to bed I sat on the sofa, ate chocolate and watched some trashy tv.

Press Release: The oceans are full of barriers for small organisms

A new study from the Center for Macroecology, Evolution and Climate at the University of Copenhagen, published in Journal of Ecology today, shows that small changes in ocean salinity and temperature can significantly affect the distribution and diversity of phytoplankton.

The paper was written by Mousing et al. and is titled; Evidence of small-scale spatial structuring of phytoplankton alpha- and beta-diversity in the open ocean.

Read the full press release from the University of Copenhagen below.


The oceans are full of barriers for small organisms

Subtle and short-lived differences in ocean salinity or temperature function as physical barriers for phytoplankton, and result in a patchy distribution of the oceans’ most important food resource. The new research from the Center for Macroecology, Evolution and Climate at the University of Copenhagen may help explain the large biodiversity in the sea.

Continue reading

Meet the Team at ESA 2016

The annual ESA meeting is fast approaching. This year it’s in Fort Lauderdale, Florida and I’ll be heading across the pond, along with Catherine Hill, our Head of Publications and Hazel Norman, our Executive Director, to chat to delegates about Journal of Ecology, as well as our other journals and the BES as a whole.

ESA 2016

ESA, Fort Lauderdale, Florida, 7th -12th August 2016

The Journal of Ecology Executive Editor David Gibson will also be attending the meeting as will several of our very hard working Associate Editors. I’m looking forward to a productive meeting with all of them and also to thanking them in person for their help towards making Journal of Ecology the success that it is.

If you’re attending ESA and are a reader of the journal, thinking of submitting, or would like to make suggestions for improvements or content, please come and find me, Catherine or Hazel at the BES stand for a chat. We’ll be at stand number 202-204.

In addition to the three of us, David Gibson along with Alan Knapp, one our sister journal Functional Ecology’s Senior Editors will be at the stand during the Wednesday 10th August poster session to answer your questions about publishing in our journals.

Finally, if you’re interested in finding out about the great work the BES does to communicate and promote ecological knowledge around the world, come and meet our amazing President Sue Hartley at our stand on Tuesday 9 August between 4.30pm and 6.30pm.

When we’re not at the stand you’ll mainly find us outside enjoying the only sun we’re likely to get this year, before heading back to grey old London!

Emilie Aimé
Managing Editor

No functional redundancy in freshwater bacterial community

New lay summary wrote by Manuel Delgado-Baquerizo about his paper”Lack of functional redundancy in the relationship between microbial diversity and ecosystem functioning” published in the last issue (July) of Journal of Ecology. Happy reading! 


The shape of the relationship between microbial diversity and ecosystem function (BEF) remains unclear, which limits our capacity to assess the impact of microbial diversity depletion on key ecosystem functions for human well-being, such as CO2 respiratory fluxes and toxin degradation. This knowledge is, moreover, key to predicting ecosystem functions under changing environment and formulating sustainable natural resource management and conservation policies. Here we conducted three independent microcosm experiments to assess the shape of the bacterial BEF relationship in multiple freshwater ecosystems from Australia and United Kingdom.

Our results provide solid evidence that unlike the positive but decelerating BEF relationship observed most frequently in plants and animals, most evaluated functional measurements were related to bacterial diversity in a non-redundant fashion (e.g. exponentially and/or linearly). Reduced bacterial diversity, even after accounting for biomass, caused a decrease in broad (i.e., CO2 respiratory fluxes: conducted by many microbial communities) and specialized (toxin degradation: conducted by few microbial communities) functions in all cases.

Altogether, our results indicate that any loss of freshwater bacterial diversity can disproportionately promote high losses in ecosystem functioning; thus the consequences of declining microbial diversity on ecosystem functioning and human welfare have likely been considerably underestimated.

Manuel Delgado-Baquerizo
Hawkesbury Institute for the Environment
Western Sydney University
Australia

 

Adaptation: an invasion mechanism adopted by an alien seaweed

Mahasweta Saha and collaborators have an interesting paper published in the last issue (July) of Journal of Ecology titled “Rapid adaptation to controlling new microbial epibionts in the invaded range promotes invasiveness of an exotic seaweed“. The lead author of this article, Mahasweta Saha, wrote a blog post below describing the context and results of her research.


Along with ocean warming and habitat and biodiversity loss, invasive species are one of the important components of global change. Rabbits are classic examples of invasive species from the terrestrial environment. According to a news article published in The Guardian in 2010, “Britain’s 40m rabbits cost more than £260m a year in damage to crops, businesses and infrastructure”. Even if we disregard the damage that they cause at national and international level, I know from my personal experience that these cute little bunnies are not welcomed at all!

My neighbours in Suchsdorf (Kiel, Germany) do not appreciate the local rabbit population as these rabbits frequently munch on their plants causing damage to their beautiful garden. In response, my neighbours installed electric wire around the garden to stop wild rabbits from entering. Initially, this appeared to be working but to our surprise, the bunnies turned out to be very smart. To cope with the new challenge of the electric wire, I observed that they simply adjusted their hop’s height and made higher hops compared to their usual ones. Thus, the smart bunnies simply adapted themselves to the new challenge that they faced in their life.

This story is very much applicable to my study published in Journal of Ecology, entitled “Rapid adaptation to controlling new microbial epibionts in the invaded range promotes invasiveness of an exotic seaweed” which involved a model seaweed Gracilaria vermiculophylla adopting a similar strategy to survive and thrive in a new invaded environment. This East Asian red algae is actually one of the top most alien seaweed species that has been introduced to Europe. It was first detected in significant amounts along the Kiel Fjord (Baltic sea) in 2005, followed by a ‘bust’ and subsequent regrowth of their population in the following years. Looking for the reasons, we analyzed the defense mechanisms of native (South Korean population) and alien Gracilaria (German and Danish population) against bacterial enemies originating from respective local habitats.

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Red algae Gracilaria vermiculophylla growing attached in stones in Nordstand (North Sea)

By an elegant experimental approach, which included a crosswise testing of alien and native populations of the algal host and co-occuring bacteria, we showed that the native and alien populations of Gracilaria were equally well defended in their actual habitat, but weakly defended when confronted to potentially harmful bacterial enemies from the other habitats. This means that, within a few years, the alien population lost its defence capacities against its old foes but acquired potent defenses against the new ones.

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M. Saha with Gracilaria vermiculophylla in the climate chamber of GEOMAR

Our study is novel and exciting because it is the first study demonstrating the role of defence adaptation to new bacterial enemies in contributing to the success of an alien plant invasion. Such adaptation dynamics could be also applicable to other types of host plants, enemy interaction in general, and for cases of shifting plant and enemy interactions under climate change.

Mahasweta Saha
Department of Experimental Ecology
Helmholtz Center for Ocean Research
Germany