The leaf economics spectrum (LES) characterizes traits and their relationships to provide key insights into the ecology of plants, and their responses to environmental change.
Ecologists believe there are six leaf characteristics of importance: photosynthesis rate, leaf nitrogen concentrations, leaf mass per area, respiration rates, leaf phosphorus concentrations and leaf lifespan. These traits tell scientists about how plants are likely to “behave,” explains ecologist Adam Martin, a professor in the Physical and Environmental Science department at the University of Toronto Scarborough.
While much is known on how LES traits vary across wild plants, less is known how these traits vary in crop genotypes growing in managed agroecosystems, such as grape vineyards.
A new study, led by Martin, and in collaboration with Niagara College’s Agriculture & Environmental Technologies Innovation Centre (AETIC) team and NC’s head winemaker, aims to explore these leaf traits on chardonnay grapes from NC’s vineyard at the Daniel J. Patterson campus in Niagara-on-the-Lake.
Martin has been working with Kimberley Cathline, project manager with AETIC; Michael Duncan, PhD, NSERC Industrial Research Chair for Colleges; and Gavin Robertson, NC head winemaker and research lead for Research & Innovation, to research where on the leaf economics spectrum grapes – chardonnay in particular – are located.
“The general thought is that grapes – and most crops – should be really “high” on the leaf economics spectrum: really high photosynthesis rates, really high leaf nitrogen concentrations, but rather flimsy leaves. This is because crops have been bred to grow very, very fast compared to all other plants in the world,” explains Martin.
“The other thing that is pretty clear is that despite these plants being genetically identical, soil compaction really dictates chardonnay leaf characteristics at the farm…”
The research also sought to figure out if individual plants of the same grape variety differ in their leaf economics traits. Since all the chardonnay grapes at the NC vineyard are made of more or less the same genetic material, Martin says it might be expected for them to have the same leaf characteristics. But things like soil compaction are likely to have a big influence on these traits.
“The final thing is to understand if these leaf economics traits predict grape yield, quality, or both – though we haven’t measured that explicitly this time around.”
Martin says the work at the College’s vineyard is “looking really good” so far. As expected, he says, grapes are fairly high on the spectrum as compared to all other plants in the world.
“The other thing that is pretty clear is that despite these plants being genetically identical, soil compaction really dictates chardonnay leaf characteristics at the farm. In areas of higher compaction, photosynthesis is reduced by almost 75 percent in some cases, and the leaves are really tough.”
However, in areas with less compaction, the chardonnay photosynthesis is right up there with some of the fastest-growing plant species in the world, like wheat or corn, adds Martin.
Ecologist Adam Martin utilized the LICOR-6800 portable photosynthesis instrument, to measure grape photosynthesis at the chardonnay vineyard at NC’s Daniel J. Patterson campus in Niagara-on-the-Lake.
Martin and the AETIC group have coauthored a poster presented at the 2020 Annual Meeting of the British Ecological Society, and will write a scientific paper related to the research, to be published likely in the next few months, he says.
“I have also been tinkering with the idea of using drones and remote sensing to measure these traits from the sky. This is really Michael’s [Duncan] specialty, so I hope and think there is some room for collaborations in this area down the road.”
What brought the University of Toronto professor to Niagara College’s vineyard for research? Martin and his wife, originally both from Welland, recently moved back to Niagara to reside in Niagara-on-the-Lake. With that move came a decision to relocate his research in agroecology from tropical regions (he used to work in coffee agroforestry systems in Costa Rica), towards something closer to home.
“Grapevines seemed like a good choice, particularly considering I love pretending to be a wine buff,” he laughs. “From there, it certainly seemed like Niagara College and their team would be an ideal place to start, in terms of sparking new research and development collaborations. Thus far, working alongside Kimberley, Gavin and Michael has been a true pleasure.”
This research is funded by the Natural Sciences and Engineering Research Council of Canada (NSERC). Martin’s lab currently has support from an NSERC Discovery grant to explore how crops respond to environmental conditions (like drought or extreme heat).
To follow Martin’s further research with the College, or to view more AETIC applied research projects, visit the website.
