BES day 2: Plants, plants and way more plants

From Sept 13

I attended the Journal of Ecology Centenary symposium all morning, where the talks were broad overviews of select areas in plant ecology. They were quite good; I really do feel that I was informed about recent research advances.

In the first talk of the morning, Sandra Lavorel gave a tour de force about how plant functional traits scale up to ecosystem services. She recognizes that there are trade offs in services, where one service (say agricultural value) is in direct conflict with a noter service (say species richness). She very cleverly asks whether these services are constrained by ecological trade offs or traits. It is known that functional traits affect ecosystem functions and services, and it is also known that there are strong tradeoffs in plant traits such as explained by the world wide leaf economic spectrum. Where plants have these tradeoffs they affect productivity and litter decomposition. Height for example affects productivity and other trophic levels supported. Abiotic gradients affect traits like height or leaf N, and these traits affect ecosystem function such as biomass or litter. Multiple service such as agronomic value, pollination, cultural value, richness, etc. To understand how traits relate to tradeoffs in services.

Next was Angela Moles who talked about how the study of invasions has progressed and whether there were important future directions. The have been 10,000 studies on invasions over the last 30 years and she recognizes that the fact that species evolve in their new ranges to be a critical future research need. Specifically, she asked: do exotics evolve to be more similar or different tha natives? And, can differences be predicted by environmental differences between home and away range. Most interestingly she brought up the point that if on-going change produce new species, should they then be conserved as natives? She went on to say that broad generalizations about trait differences between natives and exotics have produced largely idiosyncratic results, and so other priorities such take the forefront. She went on to say that impact on natives is actually an understudied problem, which needs to be rectified. Finally, she showed us that there is a generally positive relationship between disturbance and invasion. But invasions are favored when there is a change in disturbance rate, since natives are likely adapted to historical disturbance regime. She showed some relatively weak evidence that change in disturbance better predictor of invader richness and abundance then the amount of disturbance, but more work is needed.

Yadvinder Malhi talked about how productivity and metabolism were related to biomass in tropical forests. He sowed us that a small proportion of primary production is turned into biomass. Thus small changes in various pathways could have large consequences. In exhaustive studies in the tropics, he showed that increases in GPP (gross primary production) occurred with soils nutrient quality, and decreases with elevation, likely because of temperature effects on photosynthesis. He also showed that carbon use efficiency is lower than thought, about 30% of carbon turned to biomass. Further, higher productivity is associated with lower residence times, and he hypothesized that rapid growth leads to earlier senescence or less defences if trade offs exist. Biomass appears to be increasing with climate change, but potentially greater mortality and turnover.

Then James Bullock talked about where we are at with understanding seed dispersal. There has been a long history of not understanding long distance dispersal, LDD. The main empirical approaches have grown rapidly lately: tracking seeds, molecular methods and marking seeds or to track dispersers. But at the same time spread models have appeared and advanced. However, Bullock really supports mechanistic models for wind-dispersed species, and these models seem to really provide insights. He then compared a handful of models for invasive and scarce natives, and did mechanistic modeling with climate change. Changes in future wind speeds may result in even larger changes in spread rates. Only Ailanthus appears to have dispersal rates at or faster than the rate of climate change, most species do not appear to be able to move fast enough (except animal dispersed species). Movement on shoes major dispersal vector.

Hans Jacquemyn was the final speaker, and talked about evolution and habitat fragmentation. He studies calcareous grasslands, forests and heathlands in Belgium that have increasingly become isolated and fragmented. Observed declines in genetic diversity in populations, as they get smaller in size. More recent fragmentations have less loss of genetic diversity compared to older fragments. Reduced seed output in small populations for self-incompatible species, results in reduced population growth rates. To counteract plants can increase floral displays or increase selfing rates, which they observed. Also, he has observed changes in timing of flowering and investing more in nectar.

*Some thoughts about the BES. It is a great Society, and a great meeting. It is relatively small and it is nice to see how many members know each other. For those of us in North America, I think it is a great experience to go to one of these meetings.

**I also participated in the BESdigital workshop on communicating science in a digital era. I will have a post about this tomorrow –I've been without internet connection at both the Sheffield dorm and various airports.

British Ecological Society meeting: day 1, the Tansley Lecture by Diane Wall

I am at the BES meeting in Sheffield. I will be spending most of the day in journal meetings, but I was able to attend the opening lecture. I will be able to attend more talks tomorrow.

Diana Wall gave the Tansley Lecture to open the meeting. The focus of her talk was about integrating soil biodiversity into ecosystem science. She started with a quote from Arthur Tansley about how all the aspects of an ecosystem can not be ignored, and Professor Wall argues that type soils, specifically the organisms living below ground have been largely ignored, and we do now live in an era where we can study all aspects of ecosystems. Her talk showed the ways in which soil orgasims matter and how global change may have consequences for the link between soil organisms and the ecosystem functions they provide.

This is especially important because soils are deteriorating globally, and while soils are home to an impressive diversity of organisms, so little understood about these organisms. Often we do not even know how many species are found in soils (though in many cases we are talking about hundreds or thousands of species per square meter, which means we can cannot predict how global change could affect these biota and the functions they provide.

She went through three examples to highlight the importance of soil organisms and research needs to predict the impacts of global change (here global change seems broadly defined including: temperature, precipitation, land use, and water flow). In the first example, she reviews the role of soil organisms in extreme ecosystems (Antarctic and hot desert) and how climate change may alter dynamics. Experiments show how important soil organism are for flow of nutrients and energy, and global change experiments show drastic changes in their abundance, thus we should expect large consequences as environments change, especially as moisture regimes change. In different systems, the relative importance of biotic vs abiotic drivers (e.g., the presence of plants versus moisture gradients) differs and differentially important for the ecosystem effects, and so more understanding is required for predictions.

In the second part, soil animals affect soil decomposition in moist places, thus changes in moisture affect ecosystem pathways. In the third part, she outlines the ways in which soil organisms provide ecosystem services, nutrient cycling, diseases, food, food webs, biocontrol, carbon storage, waster breakdown, etc. These services have been understudied and under appreciated.

Overall this talk was a lucid and poignant call for more work to be done on soil biota -not to know what is there necessarily, but rather to be able to link together the effects of changing environments on ecosystem function.

BES day two...

It was a day full of talks, and I really enjoyed being able to spend the whole day just absorbing the presentations. Here are some highlights from today's events:

• Ian Wright gave an interesting talk about the history of functional plant ecology. Basically, covering where trait ecology has been and where we are now. It is really amazing to see the truly large scale analysis and collaborations currently driving modern trait analysis.
• In another overview type talk, Gerlinde De Deyn, talked about carbon sequestration in soils. I'm sure to many ecosystem ecologists this maybe well known, but I found it fascinating. Did you know that tundra ecosystem have as much soil carbon as tropical rain forests? The reason is that tundra has very slow process rates (cold) while rain forests have fast production rates. In fertilization experiments, soil carbon is reduced, so in order to manipulate soil carbon stores one must understand the interaction between plant traits and soil organisms.
• Finally, Kyle Dexter, in a great field survey of Inga tree species in a region of Peru, showed that different functional diversity metrics show differing patterns of over- and under-dispersion. For example, phylogenetic diversity tends to be under-dispersed for Inga assemblages, while chemical and anti-herbivory traits are over dispersed and leaf size measures are under-dispersed.
  

Also, there was the annual general meeting, which was rather somber as three obituaries were read aloud. The three deceased, John Harper, Bob Jefferies and Simon Thirgood, were all superb ecologists who absences were obviously felt. Harper (my Master's advisor's advisor) and Jefferies (my colleague at Toronto) were both eminent ecologists with long and distinguished careers, while Thirgood (a fellow Senior Editor at the Journal of Applied Ecology) was in the prime of his very successful career.

Exploring ecology through GMOs

This year's Tansley Lecture at the BES meeting was a superb presentation given by Ian Baldwin from the Max Planck Institute for Chemical Ecology. He was enjoyable to watch as his folksy, mid-western American style disarmed the listener and leaving them unprepared for his ascorbic wit and, at times, controversial message. Prof. Baldwin* is a chemical ecologist who studies plant biochemical and physiological processes and their interaction with herbivores. Through his use of molecular tools and superb natural history, he has gained new insights into how and why plants respond to herbivory. He has discovered the pathways allowing wild tobacco, Nicotiana attenuata, to detect chemicals in tobacco hornworm spit and the resulting chemical defense response. More than this though, part of his talk was about the use of transformed plants to study this plant defense response. Using genetic tools, his group was able to knockout certain segments of these biochemical pathways in order to determine how various chemicals affected hornworms. He showed chemical responses involved signaling hornworm predators whereas other responses directly targeted wornworm's ability to digest plant material.

I think that ecologists are often wary of GMOs and his talk was a convincing case for their use in basic research, and he advocated for a more reasoned approach to their use.




*Note: He has run into trouble with German authorities over using the title 'Dr.' -see here.

An ecological meeting, British style.

I'm in Hatfield, outside of London, for the British Ecological Society (BES) meeting, and I'll be blogging thoughts, happenings, etc. I posted several observations from the American equivalent (ESA) last month, and one thing is readily apparent, even though talks do not start until tomorrow. While the ESA meeting is a great chance to meet a lot of people and see a lot of talks, at a few thousand conference goers, it can be a bit overwhelming. At any given time the ESA meeting had up to 26 concurrent sessions, which makes for a lot of running around if there are talks you want to see in different sessions. At the BES there is a maximum of 7 concurrent session. The BES is definitely smaller than ESA and the meeting and venue feel compact and intimate. I'm looking forward to experiencing the BES meeting this week.

Check back for more.