We are advertising a position for a four-year postdoc to work on carbon plots and plant traits in the Amazon and Atlantic forests, as part of the new NERC project ECOFOR. The post would be 50% Oxford, 50% Lancaster. It would be based in Lancaster for the first two years, with extensive periods in Brazil getting the field operation going, and then would be based in Oxford for the second half with a focus on data analysis, databasing and writing up.
Job details at:
Closing date Wed 13th November 2013.
Feel free to contact me for any informal enquiries
There is a new paper out in Science, led by Hans ter Steege and involving just about every tree ecologist who has worked in Amazonia. It compiles data from forest plots across the region to ask some basic questions: (i) how many individual trees are there? (ii) how many tree species are there? (iii) how are tree species distributed between common and rare tree species. It comes to the surprising conclusion that only 227 "hyperdominant" species out of the approximate 16,000 tree species in Amazonia account for half of the trees in Amazonia. We estimate there are about 390 billion individual trees in the Amazon, with a mean of 565 trees per hectare (> 10 cm dbh). This hyperdominance is intriguing as to its causes, and has the potential to simplifying our understanding of the ecosystem ecology of this, the world's most biodiverse region.
The paper is here, with supplementary material and data appendices
There is a BBC news story here
Below are parts of the summary:
Results: Our analyses suggest that lowland Amazonia harbors 3.9 × 1011 trees and ~16,000 tree species. We found 227 “hyperdominant” species (1.4% of the total) to be so common that together they account for half of all trees in Amazonia, whereas the rarest 11,000 species account for just 0.12% of trees. Most hyperdominants are habitat specialists that have large geographic ranges but are only dominant in one or two regions of the basin, and a median of 41% of trees in individual plots belong to hyperdominants. A disproportionate number of hyperdominants are palms, Myristicaceae, and Lecythidaceae.
Discussion: The finding that Amazonia is dominated by just 227 tree species implies that most biogeochemical cycling in the world’s largest tropical forest is performed by a tiny sliver of its diver- sity. The causes underlying hyperdominance in these species remain unknown. Both competitive superiority and widespread pre-1492 cultivation by humans are compelling hypotheses that deserve testing. Although the data suggest that spatial models can effectively forecast tree community com- position and structure of unstudied sites in Amazonia, incorporating environmental data may yield substantial improvements. An appreciation of how thoroughly common species dominate the basin has the potential to simplify research in Amazonian biogeochemistry, ecology, and vegetation map- ping. Such advances are urgently needed in light of the >10,000 rare, poorly known, and potentially threatened tree species in the Amazon.
There is what appears to be a stunning new film on tropical forests, featuring the work of Francis Hallé. Much of it was filmed in Gabon and in Manu, Peru. It is all in French but even if you don't speak French the visuals are stunning
The trailer is worth a watch, and can be seen (after the advertising) at.
There is also a segment of the associated e-book available (with many photos from our friend Jake Bryant). It is available to peruse here:
The film is released in France next month. I am not sure if there will be a UK release, but do expect so.
This Saturday, a new six-part series, "The Tipping Points" premiers on the Weather Channel in the USA (and will eventually be distributed worldwide). The first episode (on Sat Oct 19th) is about the Amazon, and features our research in Brazil, including the drought experiment at Caxiuanã (run by the Federal University of Para and Edinburgh University). See the website at:
And here is a preview article in the Huffington Post
There are some short preview video snips here.
And here is a video piece on the Caxiuanã drought experiment
Term had kicked off in Oxford and here are two lectures I have just given in the opening week series "Welcome to the Anthropocene"
A short history of the biosphere (35 MB).
This lecture is part of the “Welcome to the Anthropocene” series on “Introduction to timescales”. In this lecture, I address such topics as: (1) key components of the biosphere over Earth’s history, from evolution of photosynthesis to present. (2) Mass extinctions and periods of rapid climate change - the Palaeocene-Eocene thermal maximum and glaciations. (3) Contemporary global change in the context of Earth history. (4) The concept of the Anthropocene.
The metabolism of a human-dominated planet (56 MB)
This lecture explores how human activity and use of the biosphere has changed through human history and pre-history, through hunter-gatherer, agrarian and industrial modes of society. I discuss the concept of describing human activity and material and energy use through social metabolism, and compare with the inherent biological metabolism of the biosphere. I explore a range of ideas and bizarre questions such as: to what extent can human societies be considered as superorganisms? In what way are cities more like stars rather than like ant colonies?
The T-lidar team have been busy in Gabon and are now in Peru. Here is a fly-through of a tropical forest plot in Gabon, showing the forest structure in incredible detail. From this we can work out details of tree from and architecture and ecosystem structure.
Working together with a team from Wageningen University in the Netherlands and University College London, we are exploring the potential of T-lidar laser scans to map the structure and form of tropical forests. In August and September, the team visited our GEM plots in Gabon. While at Lope National Park, an elephant (a solo male called Billy) passed by and became the first 3D laser scanned elephant ever! The colours in the first image indicate height above ground.
Now the team has just arrived at Tambopata, Peru, where they will be scanning our plots along the Amazon-Andes transect over October. Over the next year we will build up an exciting dataset on the struc
I have spent the last few days visiting the forests of the Big Island of Hawaii, hosted by Greg Asner. We are looking to bring the long-term ecosystem studies going on here into the fold of our global ecosystems monitoring project, GEM. As well as being fascinating in themselves, Hawaii's forests bring lots of advantages as this is where much of our understanding has been developed on how nutrient cycling changes with ecosystem development. The substrate is all volcanic lava, with forests growing on lava soils ranging from a few hundred years to hundreds of thousands of years.
The other astonishing thing about Hawaii is the lesson it provides in invasion ecology. The native plant and animal species of Hawaii are descendants of the few that made it across the vast stretches of the Pacific by wind, ocean currents or animal transport. There they have evolved, diversified and radiated into many unique species that are found only in Hawaii. The absolute levels of diversity are low compared to, say, Amazonia, but the levels of endemism (species found here and nowhere else) are extremely high.
Since humans arrived about a millennium ago, and particularly in the last century, they have been bringing in outside species and rapid rates, whether by accident or design. Many of these species are invading and altering native ecosystems. One extreme example is strawberry guava Psidium cattleianum, native to the Atlantic rainforests of Brazil. In Hawaii it forms incredible dense thickets that suppress other vegetation, and an advancing front that is gradually marching through the forests. Hawaii is in the front line of understanding ecological invasion and how to stop it.
This video shows when the Carnegie Airborne Observatory flow low over our plots in the Kosnipata Valley, on the eastern slopes of the Peruvian Andes. These are the same plots where our field team has been collecting canopy data since April, as part of a major field campaign funded by NERC and the European Research Council. Amazing flying in an amazing place. We aim to link our ground observations with the maps of chemistry and structure that the CAO is producing. Together we will ending up with amazing new insights into the ecology of the Amazon and Andes.
Yadvinder Malhi is an ecosytem ecologist and Professor of Ecosystem Science at Oxford University