The cover image for New Phytologist 214:3 accompanies the Feature Issue, Tropical plants and ecosystem function. In our latest Behind the Cover, we talk to Cecilia Chavana-Bryant, who spent two years undertaking fieldwork in the Amazon, and who contributed two articles to the Feature issue, and to documentary photographer Jake Bryant who captured the image. We learn about Cecilia’s research, and how images such as this can help disseminate important research, such as that highlighted in this Feature issue, and beyond.
Capturing the canopy
Cecilia: The cover image for this issue shows an area of primary rainforest in the Amazon, it was captured early in the morning while flying on a helicopter on our way to our research field station. Mist can still be seen on the horizon as moisture accumulated in the forest overnight starts to evaporate after sunrise.
I was very lucky to have a professional photographer, Jake Bryant, document my fieldwork. This photograph was shot from a helicopter using a Nikon D3 and 24mm lens. Jake used a secondary camera strap attached to his seatbelt, so that the camera didn’t get sucked out of the door. In this photograph, Jake balanced the horizon with the height and canopy depth of the trees so the viewer feels immersed in the image and what it is like to experience this view. Minimal post-production was used to fine-tune the colour balance of the photograph. Light is the most important aspect of photography and we were fortunate to have such a beautiful morning for this photograph.
Jake: As a visual documentarian, I’m interested in the interaction between scientists and the environments they study. I’ve been fortunate to have worked on various international research campaigns. Each project is different, but my overall approach is to highlight both the research and the scientists themselves through portraiture. My work takes me to remote and challenging locations, where few people other than researchers venture. During my assignments, I have witnessed the remarkable and sometimes precarious lengths to which scientists go to obtain a better understanding of the ecosystems they study. It is hugely demanding to carry out scientific experiments and data collection, and indeed to photograph this work, in remote tropical forests. However, it is always a pleasure to document this cutting edge research and the international camaraderie that results from this demanding work. Moreover, it has been a joy to have worked so closely with such talented scientists and to capture a part of their professional lives that I believe, should be better understood and witnessed by the public at large.
Exploring leaf traits in the Amazon
Cecilia: The aim of my research was to investigate how the age-related morphological and biochemical changes in Amazonian canopy leaves are captured by hyperspectral leaf measurements and to use these data to develop a novel, efficient and accurate spectral approach for determining leaf age. This study was the first to use spectral approaches (i.e. develop a spectral leaf age model) to predict leaf age and to explore how the leaf lifecycle can have direct influence on remotely sensed vegetation indices (VIs). It highlights the importance of leaf age as a mediator of leaf traits; provides evidence of age-related leaf reflectance changes that have important impacts on VIs used to monitor tropical canopy dynamics and productivity; and proposes a new approach to predicting and monitoring leaf age with important implications for remote sensing. This research is important as leaf demography has been proposed as a major driver of seasonal productivity in carbon-rich tropical forests and because it opens up the possibility of incorporating leaf ages and the corresponding age-trait relationships to improve vegetation demographic models.
In a follow-up study, the generality of the spectral leaf age model was successfully tested by application to an independent data set from a different Amazonian forest site and by application to contrasting canopy light conditions (sun versus shade).
Beyond the rainforest
Cecilia: I think this image illustrates perfectly the beautifully diverse and complex canopy structure that researchers will encounter in the tropics. In my case, images such as this helped me to prepare for the challenges of accessing, climbing and moving around the canopies of some of the tallest trees in the Amazon. I spent two years climbing trees 30 to 65m tall to monitor the lifecycle/phenology of their canopy leaves and collect leaves of different ages. A short video documenting my fieldwork and aimed at the general public can be accessed at: https://vimeo.com/208748496, and below.
Jake: I am lucky to have been involved in documenting very interesting research projects around the world and two of these projects stand out. The first was an exhibition funded by the National Science Foundation entitled “What happens in the rainforest doesn’t stay in the rainforest”. It was aimed at communicating scientific research to public audiences, particularly children. This assignment covered multiple trips across the Amazon basin to document the Amazon PIRE project which was a collaboration between the University of Arizona, Harvard, and Brazilian counterpart organisations such as the University of Såo Paulo and INPA. The exhibition combined audio narratives from the scientists themselves with video animation and large format photographic prints. It was hosted at the Ironwood Gallery in the Arizona Sonora Desert Museum and was visited by four thousand people over a five-week period. The exhibition’s website can be found at: http://www.jakebryantdocumentaryphoto.com/exhibition/
I also worked alongside filmmaker Luc Jacquet in documenting the production of the French documentary “Il était une forêt” or “Once upon a forest”. This documentary offers a cinematic natural history lesson about rainforest flora and features the research of renowned botanist Francis Hallé. I shot one of my favourite photographs during this assignment, it captures Francis sketching the canopy structure of a large Moabi tree while sitting at the centre of its crown 40m above the forest floor as seen below. More images from this assignment can be seen at: http://www.jakebryantdocumentaryphoto.com/#/weg/
Read the papers
McDowell N.G., Xu C. 2017. Using traits to uncover tropical forest function. New Phytologist. doi: 10.1111/nph.14576
Asner GP, Martin RE, Anderson CB, Kryston K, Vaughn N, Knapp DE, Bentley LP, Shenkin A, Salinas N, Sinca F et al. 2017. Scale dependence of canopy trait distributions along a tropical forest elevation gradient. New Phytologist. doi: 10.1111/nph.14068
Goldsmith GR, Bentley LP, Shenkin A, Salinas N, Blonder B, Martin RE, Castro-Ccossco R, Chambi-Porroa P, Diaz S, Enquist BJ et al. 2017. Variation in leaf wettability traits along a tropical montane elevation gradient. New Phytologist. doi: 10.1111/nph.14121
Bahar NHA, Ishida FY, Weerasinghe LK, Guerrieri R, O’Sullivan OS, Bloomfield KJ, Asner GP, Martin RE, Lloyd J, Malhi Y et al. 2017. Leaf‐level photosynthetic capacity in lowland Amazonian and high‐elevation Andean tropical moist forests of Peru. New Phytologist. doi: 10.1111/nph.14079
Malhi Y, Girardin CAJ, Goldsmith GR, Doughty CE, Salinas N, Metcalfe DB, Huaraca Huasco W, Silva-Espejo JE, del Aguilla-Pasquell J, Farfán Amézquita F et al. 2017. The variation of productivity and its allocation along a tropical elevation gradient: a whole carbon budget perspective. New Phytologist. doi: 10.1111/nph.14189
Chavana-Bryant C, Malhi Y, Wu J, Asner GP, Anastasiou A, Enquist BJ, Cosio Caravasi EG, Doughty CE, Saleska SR, Martin RE et al. .2017. Leaf aging of Amazonian canopy trees as revealed by spectral and physiochemical measurements. New Phytologist. doi: 10.1111/nph.13853
Wu J, Chavana-Bryant C, Prohaska N, Serbin SP, Guan K, Albert LP, Yang X, van Leeuwen WJD, Garnello AJ, Martins G et al. .2017. Convergence in relationships between leaf traits, spectra and age across diverse canopy environments and two contrasting tropical forests. New Phytologist. doi: 10.1111/nph.14051
Rowland L, Zaragoza-Castells J, Bloomfield KJ, Turnbull MH, Bonal D, Burban B, Salinas N, Cosio E, Metcalfe DJ, Ford A et al. 2017. Scaling leaf respiration with nitrogen and phosphorus in tropical forests across two continents. New Phytologist. doi: 10.1111/nph.13992
Managing Editor, New Phytologist