Two new papers have just been published from our RELATED project. The work shows how future changes in forest cover around lakes will influence the contributions of inland waters to global carbon cycles.
The first paper published in ISME finds that the positive effects of microbial diversity on CO2 production depends on present and past environmental gradients. Using a space-for-time substitution for forest greening, the study also finds that a doubling in the tree cover around lakes can increase CO2 production by five-times. More broadly, the work highlights how widely reported biodiversity-ecosystem functioning relationships need to be contextualised with other ecosystem properties.
A second paper published in Global Change Biology sheds light on the mechanisms underpinning the decomposition of terrestrial organic matter in lake sediments. Using the RELATED experimental platform, the study finds that identical organic matter additions to sediments have contrasting outcomes for carbon cycling depending on lake-specific characteristics. In lakes with clear waters, future increases in terrestrial organic matter inputs can stimulate CO2 production because of photo-oxidation. By contrast, bacteria in darker waters may possess functional genes for degrading organic matter, thereby priming their productivity. I’m particularly proud of the teamwork on this one, which involved almost the entire group!
The Tanentzap group have launched a new website at www.ecosystemchange.com. Check it out!
We will however continue to provide all our latest news here.
Lakes release gas too. In the latest paper freely available from our RELATED project, we show that the vegetation in and around lakes can play an important role in influencing how much of the potent greenhouse gas methane is produced by microbes. The story, led by our former postdoc Erik Emilson, has been covered by BBC News.
Congratulations to our former intern-extraordinaire Beth Smith who’s just published her undergraduate research on how mussels can both outweigh and interact with the effects of terrestrial to aquatic resource subsidies on nearshore lake biogeochemistry. The work was part of our larger NERC RELATED project.
The results are summarised below. Well done Beth!
We recently featured in a terrific new documentary called What Trees Talk About. The film was shot in 2016 during our summer field campaign and is freely available online in Canada.
Here’s a condensed version for the early career scientists:
Protected areas deliver enormous benefits inside of their boundaries, but what is their contribution to the biodiversity of broader landscapes? This is a really important question to answer because there are limits to how much land conservation can meaningfully protect. Moreover, the 196 governments parties that have signed onto the Convention on Biological Diversity are aiming to protect 17% of the world’s land surface by 2020, but what about the other 83%? Conservation outside of protected areas is critical to ensure that the spaces between parks aren’t devoid of life.
How do we get species from one side of the fence to the other?
In a new study, we provide among the first empirical evidence that protected areas may disperse biodiversity and ecosystem services into surrounding landscapes. Continue reading
Fifty football pitches worth of forest were apparently lost every minute between 2000 and 2012 according to a recent paper by Matt Hansen et al. And there is little reason to expect this to be different today. This tremendous pace of forest loss is mostly driven by the clearance of land for agriculture, yet comes at a tremendous cost to the other benefits that people obtain from forests, including carbon sequestration, water purification, and biodiversity.
In a new primer for PLoS Biology – think tutorial more than review – we deliver an overview of the global challenge of reconciling forest conservation with land clearance for agriculture. We explain how the economic valuation of ecosystem services can provide a way to choose between allocating land to either conservation or development, highlighting a new paper in PLoS Biology by Roman Carrasco and colleagues. In their paper, Carrasco et al. test how different scenarios of global agricultural production might trade off against the multiple ecosystem services delivered by tropical forests. They find that the value of those services destroyed by deforestation exceeds the economic benefits of agriculture, except in a few regions if greater yields of high-value crops are eventually realised. Together, the analytical framework and results of Carrasco et al. should inform the spatial prioritisation of real-world interventions such as REDD+ and can help deliver better environmental and economic outcomes worldwide. Definitely worth a read!
Our latest paper examining the role of life history traits in explaining the vast unevenness of species diversity across the flowering plant Tree of Life has just appeared online at PLoS Biology. The paper was led by Javi Igea and emerged from a very successful BBSRC DTP rotation project by Eleanor Miller, in collaboration with Alex Papadopulos.
Using the largest available phylogenetic tree of plants coupled with an unparalleled trait dataset, we analysed how seed size and its rate of change across the phylogeny were correlated with the rate of species formation. Seed size is crucial to plant evolution because it confers adaptation to different environment conditions and influences many other aspects of life history, including dispersal, resistance to stress, and colonisation potential. We subsequently found that faster rates of seed size change were associated with faster rates of speciation, probably by fostering the appearance of reproductive barriers between lineages. We also found that smaller-seeded species speciated faster than larger-seeded ones. These results underscore the importance of morphological traits, and particularly their rate of evolution, in promoting species divergence across one of the largest radiations of organisms on the planet.
Although it has taken a bit longer than we would have liked – no thanks to some poor timing with #BAMMgate – the paper brings together an impressive toolbox of complementary macro-evolutionary analyses to deliver a compelling explanation for one of nature’s enduring mysteries. Well done all!
Our latest paper has just appeared in Science Advances. In it, we present widespread evidence that aquatic consumers use terrestrial resources depending on the features of surrounding catchments. It is really nice to see this out as it caps the food web workshop we organised in Cambridge more than two years ago and includes data we collected during our summer 2014 field campaign. There’s a nice write up of the work put out by our friends at the Cary Institute.
The work emerged out of our forest fuel fish growth story, which hinted that there can be a lot of variation in the extent to which lake food webs use terrestrially derived material, depending on the features of the surrounding catchments. With funding from a NERC collaborative grant, our new paper managed to assemble the largest dataset to date of the isotopic composition of zooplankton and their associated food webs from across 147 lakes spanning the boreal to subtropics. Our aim was to address the use of terrestrial resource in lake food webs once and for all.
Algae and land plants differ in their assimilation of heavy versus light forms of atoms such as carbon, allowing the ratios between these two forms to be used as dietary tracers. Using these isotopic signatures, we discovered that half of all the zooplankton samples we amassed were comprised of at least 42% terrestrially derived material, but this was underpinned by large variation ranging from 11 to 83%. Using some awfully complex stats, we go on to show that terrestrial support of zooplankton was generally greatest in lakes with long shorelines and surrounded by dense vegetation and rich soils. This work now explains the large variation in terrestrial resource use by aquatic food webs and delivers a major advance towards resolving the ‘controversy’ around this process.