Overview of Results and Discussion from the SESYNC Venture
“A Scoping Workshop on the Macroevolution of Ecosystem Services”
Co-PIs: Nathan Kraft, University of British Columbia
Bill Fagan, Associate Director of Research Innovations, SESYNC
Participants:
Amy Ando -- University of Illinois – Urbana/Champaign
Jeannine Cavender-Bares -- University of Minnesota.
Emma Goldberg -- University of Illinois –Chicago
Erik Nelson -- Bowdoin College
Nate Swenson -- Michigan State University
This venture was proposed as a novel synthesis idea that should be considered high-risk/high reward. It has the
potential to open doors to new areas of investigation and may lead to the development of new methods. The goal
was to assemble a small group for a one-time scoping meeting in which participants would explore existing work,
learn about existing data resources, methodologies, and perspectives, and identify possible directions and specific
research questions within the broader subject of the macroevolution of ecosystem services. Preliminary
discussions outside of SESYNC identified multiple directions this group could go that would be innovative from
the perspectives of diverse disciplines. For example, a team could put economic values on tree traits, map the
traits across a landscape, and then convert the trait maps into maps of economic value. The economic value and
ecosystem services of alternative land uses could be quantified based on different (hypothetical or real) species
occurrence scenarios. Alternatively, a team could focus on the tree traits that humans have tended to promote over
time on different landscapes. Economic valuation perspectives could then explore the evolutionary tradeoffs
among several tree traits related to ecosystem services that occur in different combinations across phylogenetic
trees. This latter idea, which would quantify the consequences of 'landscape-scale artificial selection' from an
ecosystem service perspective, might afford a path toward quantifying 'evolutionary opportunity costs.'
At SESYNC, the working group identified a set of closely related fundamental questions under the umbrella of
the macroevolution of ecosystem services. The team then distinguished an interlinked set of ground-level topics
from several follow-up questions that were of equal or greater interest levels, but which hinged on having the
fundamental work in place.
Fundamental Questions:
1. How do the ecosystem services that tree species provide differ among species and how have the specieslevel, ecological traits associated with those services evolved ?
We divided services (according to MEA) into provisioning, regulating, aesthetic, and habitat related services.
Provisioning would include e.g., food, fuel, construction; regulating would include carbon sequestration, soil
protection, wind protection, etc; aesthetics would include showiness, leaf color, ornamental trees; Habitat would
include services that support the maintenance of biodiversity. For each of these services, we had identified
examples of traits that could be qualitatively or quantitatively identified. For example, for food the edible
components (nuts, fruit) would be scored; fuel: charcoal, firewood use; construction: architecture/straightness of
trunk; carbon sequestration: density, volume, growth rate; protection: rooting depth, rooting volume; wind
protection: wood density, longevity; Aesthetics: showiness of flowers, leaf coloration etc.). Traits would be
combined by functions to derive the links between species and services.]
2. What evolutionary tradeoffs (i.e., inverse correlations) exist among different service-related traits across
species, and how do these tradeoffs correspond to changes in economic value ?
Contingent, Follow-up Questions:
A. What parts of the ecosystem services spectrum provided by trees are threatened by extinction and landuse
change ?
B. Can we quantify something like an evolutionary cost corresponding to the loss or ‘functional extinction’
of taxa ? This could depend on the level of uniqueness present in trait combinations across tree species
and on the degree to which trees with similar traits are substitutable.
C. How are different human behaviors (landuses, landuse changes, choices about species type in managed
settings) shaping and thinning the spectrum of ecosystem services that trees provide ? Operationally,
can this be envisioned as a kind of landscape-scale artificial selection ?
Questions B and C received consensus support, but the group felt that they would be most easily addressed via
regional case studies that could tap into the database of traits developed under Question 1 to explore alternative
scenarios of species distribution in response to human decisions about which species are cultivated where.
Economic analyses linking tree traits to dollar denominated valuations would be necessary to answer these
questions quantitatively, and they would require substantial effort (e.g., Masters thesis) to undertake. They would
also require spatial information about both species and land-use changes. Jamie Gerber (works with Jon Foley)
was mentioned as a potentially valuable participant in future efforts on these topics.
Additional Ideas Worthy of Investigation:
a.
b.
How do forestry efforts that prevent the persistence of extraordinarily old trees influence evolutionary
processes / population genetics of managed species ? This topic, which has close connection to issues
in the fisheries literature, could hinge on the effect of management practices on reproductive skew in an
age-structured population. This is a microevolutionary question that complements the overall
macroevolutionary issues.
What do realized patterns of sales of nursery trees tell us about tree-based ecosystem services people are
favoring in different landscapes ? (Amy is interested in pursuing this with a student)
Issues / Discussion Points Related to Question 1
 How context-based (setting-dependent) are the ecosystem services provided by particular species? That is,
for some types of ecosystem services (e.g., aesthetics, human food), particular species may provide those
services in some regions but not others. Likewise, some physical plant traits may vary regionally such that
carbon-related services also vary spatially. Consensus seems to be that these issues, while interesting,
would not be addressable in a global scale analysis, but would be ripe for a comparative analysis contrasting
particular ‘zoomed in’ localities.
 A related topic is the ‘regionality vs. redundancy’ issue: How much biogeographical variation exists in
which species provide which services in particular localities, and to what extent are such species are
substitutable across space. Similarly, there is the key question: Are the (phylogenetically corrected)
correlations between traits location-specific ? The first step is non-spatial: for each service, map it on the
phylogeny, e.g., all fruit trees. Then zooming in on different spatial locations, quantify how that
redundancy is reduced. An economics phrase for an extreme case of this was "non-substitutable cultural
values." These issues also lend themselves to a ‘beta diversity’ approach to understanding the distribution
of ecosystem services across species and space.
 A map of production diversity vs. consumption diversity of ecosystem services would be useful. Economic
valuations could perhaps also be placed on such a map, and the valuations could be correlated with local
standing diversity. The idea is to quantify humanity’s "phylogenetic footprint" with regard to particular
ecosystem services.
 One additional outcome of this type of synthesis effort could be a highlighting of data gaps, and the lack of
societal investment in data collection and knowledge about fundamental ecosystem services critical to
human well-being. Overall, the study could point out that even if biodiversity as a concept is a bit
amorphous to the general public, phylogenetic biodiversity in particular matters to human well-being
because of the prevalence of partial- and inverse-correlations ecosystem services across taxa.
 How much ‘trait space’ have humans been able to reproduce synthetically in X years compared to the
spectrum of evolved traits ? This perspective would provide some quantification of the limits of human
ingenuity as a replacement of nature. For example, rubber from the tree Hevea brasiliensis (one of the three
materials critical to the industrial revolution) can be synthetically produced, but synthetic rubber does NOT
work for many purposes (e.g., airplane tires, O-rings in space shuttles etc.). Related to this is the outreach
message that evolution is responsible for the existence of ecosystem services. Indeed, even our artificial
efforts rely on biological raw ingredients, certainly for selective breeding and GMOs, and perhaps also for
inspiring synthetic materials.
 Globalization angle: how much phylogenetic diversity do peoples in different parts of the world access in
their day-to-day lives ? How has increased trade affected that the breadth of that interface between
biodiversity and people ?
 Extinction risk: How is threat status (as a proxy for extinction risk) distributed on the phylogeny relative to
the
distribution of various ecosystem services. This could also include a regional zoom-in.
Issues considered:
 Should we do analyses for all trees despite their polyphyletic nature or for a particular clade of species
with mostly tree lifeforms (e.g., Coniferales, Sapindales, Fagales) ? Consensus seems to be to do the
analyses for the larger group because of the greater diversity of ecosystem services potentially
represented. Quantitative techniques exist for handling the mix of discrete and continuous traits, and can
accommodate the polyphyly, but must be interpreted carefully because of the likelihood of extensive
missing data.
 What should be the geographic scope of the analysis: North America north of Mexico vs. Western
Hemisphere vs. Globe ? Consensus seems to be North America north of Mexico for some analyses and
Western Hemisphere for others.
 What specific, quantitative analyses could be undertaken: Consensus seems to be to ask first ‘where are
the traits located on phylogenetic trees’ ? and later, perhaps for a clade that is particularly data dense, ask
‘what are the apparent rates of evolution of traits that are related to ecosystem services’ ?
 Need for a protocol model for data collection
General Quantitative Approach:

Do a PCA of the set of traits responsible for each ecosystem service to reduce the multivariate data to one
point per service category per species. Place the PCA loadings on species tips in a phylogeny and
calculate phylogenetic independent contrasts between species pairs for each service. Then, for each pair
of services, plot the contrasts of PCA loadings against one another to test for positive and negative
correlations among pairs of services. On these scatterplots, how do the positions of the taxa that humans
favor in one or another occur relative to the ‘efficiency frontiers’ (or realized geometric bounds) of
service tradeoffs ? In some cases, it may be necessary to modify correlations so that taxa are weighted by
economic value.
Ecosystem Service Categories
Traits Involved
Datasources
Erosion / Wind Protection
Rooting Depth, Wood Density
Massive undergrad labor
Dataset on oaks
Aesthetic
Flower color, Flower size ,
Tree Shape
Kew Gardens seed database
BIEN database
Lit. Review of Regional Floras
Pollination
Insect pollinated (Y/N)
Kew Gardens seed database
FIA database
Habitat for Other Species
Eaten by non-human
vertebrates (Y/N), Height,
Diameter at Breast Height
Height, Diameter at Breast
Height, Longevity
Literature Review
Carbon Stocks
Carbon Flux
Human Food
Pharmaceuticals
Commercial Construction
Age at which trees stop
growing in size
Eaten by humans (Y/N)
Number of pharmaceutical
products per species
Wood density, trunk
straightness, tree height
TRY Database
Other ecological datasets
FAO database
TRY database
FAO database ?
USFS wood fiber database
To move to the next stage:
The working group needs to be expanded to bring in additional expertise.
Recommended New Participants:
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One representative from IpTOL (I-Plant Tree of Life):
 Steven Smith (U. Michigan, EEB)
 Michael Donoghue (Yale)
 Michael Sanderson (Univ. Arizona)
 Bill Piel (Yale)
David J. Nowak (USDA economist quantifying the value of trees in urban systems)
 UFORE; I-tree
Ivan Eastin (Wood products expert; University of Washington)
Jan Salick (Comparative Ethnobotanist; Missouri Botanical Garden)
James Stegen (max height predicts biomass at plant scale; UNC postdoc)
An anthropologist (how people do people value trees)
An environmental psychologist
Brazilian Wood Products expert from INPA