James J. Elser, Ph.D. - US grants

Ecologists are increasingly realizing that patterns of storage and processing of energy and chemical elements in ecosystems are strongly influenced by the composition of the ecological communities present in the ecosystem. In lakes, the abundance of "top predators" (i.e. fish-eating fish species like bass) can have strong effects on all levels of the system, including the abundance and productivity of plant producers and the cycling of chemical elements. This occurs because predatory fish consume plankton-feeding fish, like minnows, which in turn influence herbivorous consumers (zooplankton). Finally, zooplankton both regulate the abundance of plant producers (phytoplankton) and decomposers (bacteria) and recycle nutrients. This project focusses on the effects of food web structure on the relative availability of nutrient elements critical for microbial growth (nitrogen and phosphorus). It tests the predictions of a recently-developed, physiologically-based theory designed to understand how different zooplankton species regenerate nitrogen and phosphorus present in their food. By altering the dynamics of these herbivorous zooplankton, fish predation can therefore influence the cycling of nitrogen and phosphorus. Based at the Experimental Lakes Area in Canada, the main research approaches will in involve experimental manipulations of nutrients and zooplankton in large enclosures in lakes as well as whole-lake manipulations of food-web structure (via introduction of pike to two lakes which lack such a fish-eating species). THese studies have direct application to understanding the processes controlling elemental cycling in ecosystems; such processes play a critical role in various areas of direct societal, including global climate change, the dynamics of contaminants in the environment, and degradation of water supplies.

9317340 Grimm

This proposal is submitted under a special pilot program, Undergraduate Mentorships in Environmental Biology. The four year program will offer undergraduate students first hand experience in carrying out ecological research under the mentorships of six active research ecologists. We will aggressively seek to involve groups traditionally under represented in environmental biology, includi ng trainees of Latino, American Indian, and African American backgrounds as well as a number of non minority students. This effort will be aided considerably by close coordination with existing programs that target these minority groups at ASU. The program is a specialized educational track consisting of an integrative first year seminar, early exposure to advanced courses, research involvement at the outset of students' college careers, and continued follow up and support of individual students as they make plans for graduate school and future careers. Careful documentation of the program's successes and failures, support from other research experience programs targeting more advanced undergraduate students, and placement of students in individual laboratories will facilitate the entry of alumni and alumnae of this program into research careers in environmental biology.

9511838 Elser This Americas Program award will support travel and related expenses for eleven U.S. scientists and five graduate students, to participate in a joint U.S./Mexico workshop to be held in Guaymas, Mexico. Organizers are Dr. James Elser, Arizona State University, and Dr. Edward Pfeiler, Instituto Tecnologico y de Estudios Superiores de Monterrey (ITESM), Sonora, Mexico. The workshop will focus on the environmental biology of the coastal Sonoran region as a step towards increasing scientific exchange between U.S. and Mexican scientists in this ecologically diverse desert-ocean landscape. The potential for transnational and global environmental disruptions, including climate change, pollutant transport across international boundaries, and biodiversity loss, has increased with the global economy. This potential is especially strong in the environmentally sensitive and economically dynamic U.S.-Mexico boundary region and calls for increased international scientific exchanges in the area of basic and applied environmental biology. This workshop will bring together senior scientists, and students from both the U.S. and Mexico, to identify research questions of mutual interest for future investigations. ***

Elser 9527322 How does elemental composition ("stoichiometry") of animals vary among species? How might differences in body elemental composition affect how food webs function? This project will test the hypothesis that differences among species in body stoichiometry of the nutrients nitrogen (N) and phosphorus (P) reflect differences among species in specific growth rate. It is predicted that rapidly growing organisms must have high ribosome concentrations in their bodies. Ribosomes are P-rich (low N:P) cellular structures responsible for protein synthesis and thus growth. Therefore, rapidly growing organisms are predicted to have lower N:P ratios in their bodies that slower growing species. We will test this hypothesis by studying elemental and biochemical composition and body growth rates of zooplankton species at high latitudes vs. mid-latitudes. Natural selection along latitudinal gradients is hypothesized to select for differing growth rates among similar planktonic species. We will study ecological and evolutionary determinants of a parameter, animal N:P stoichiometry, that is likely to be a key factor influencing food webs of lake and ocean ecosystems.

Elser 9725878 Ecologists have been increasingly aware of the fundamental importance of differences in the elemental composition of organisms that comprise the food webs of ecosystems. Elser, the PI on this proposal, has been one of the leaders in developing this field termed ecological stoichiometry. The work supported by this project will combine modeling investigations with experiments in field and artificial enclosures to examine the joint effects of light and nutrient availability on the organization of aquatic communities in pelagic habitats. Specifically it will test whether different light and nutrient conditions can shift pelagic communities into fundamentally different states by altering the ecological stoichiometry of dominant interactions. Modeling studies will evaluate the potential for alternate states in which one is dominated by quantity effects such as where low algal biomass limits growth by grazers and the alternate is driven by nutritional effects where poor algal food quality can limit grazer growth. Modeling results will be tested in field manipulations conducted at the Experimental Lakes Area in Canada and in artificial mesocosms at new, state-of-the-art facility at Kyoto University in Japan. Experiments will involve manipulations of light and starting grazer conditions to test predictions from the model on these alternate ecosystem states. This work will contribute to the understanding of the interface between population dynamics and ecosystem function. It has substantial theoretical and practical implications.

9977047
Elser
The IRC-EB Program seeks to promote research that integrates across multiple levels of biological organization and across diverse types of habitats and organisms. Such work should articulate general principles that can begin to re-unify the increasingly fragmented wealth of biological knowledge that this century has generated. This project involves a diverse team of researchers that includes a physiologist, a microbial ecologist, theoretical biologists, evolutionary biologists, limnologists, and a terrestrial ecosystem ecologist. It involves an explicit, conceptually organized, integration from genes to ecosystems, from microbes to metazoans, and from lakes to deserts. This project will use a framework of biological stoichiometry to assess how the fundamental chemical balance required for growth links the genetics and physiology of organisms to ecosystem dynamics. Biological stoichiometry is the study of the balance of energy and multiple chemical elements in living systems. Accumulating research suggests a characteristic biogeochemical signature of rapid organism growth, manifested in biomass C:N:P stoichiometry, which is driven by the fundamental association of rapid growth with P-rich ribosomal RNA. In addition, considerable data are accumulating that indicate that organism C:N:P stoichiometry is a key mediator of ecological dynamics, including trophic dynamics and biogeochemical cycling in ecosystems. Thus, there appears an opportunity to use principles of chemical stoichiometry to derive the causal connections between the genetics and cellular physiology of growth with major ecological implications. This 4-year project will make this attempt via three closely intertwined components. In Component 1 (Organismal Biology) the coupling of growth, biochemical composition (RNA concentration), and C:N:P will be examined in a suite of organisms whole nutritional physiology has not been well studies (bacteria, protozoa, fungi, insects, worms). Patterns of C:N:P variation and growth will be assessed in these taxa relative to patterns known from better-studied groups. How terrestrial and aquatic metazoan herbivores with contrasting C:N:P composition cope with food resources that are stoichiometrically imbalanced with respect to their requirements. These studies will examine both behavioral and physiological adjustments by animals in response to stoichiometric food quality. Component 2 (Evolution) will consider organism growth, C:N:P, and biochemical allocation in an evolutionary context in both terrestrial (Drosophila) and aquatic (Daphnia) realms. How these phenotypic traits, as well as key genotypic features associated with the genetics of the ribosome (such as rDNA intergenic spacer length and gene dosage) are arrayed on known phylogenetic trees will be investigated. Drosophila and Daphnia will be subjected to artificial selection on growth rate, and how growth rate, C:N:P, RNA allocation, and ribosomal genotypes change in concert will be examined. At the end of these divergent selection regimes, the consequences of selection for physiological, behavioral, and ecological features will be assessed for each taxon. The implication of growth-C:N:P coupling in theoretical studies that permit in situ evolution of ecological communities under multiple resource limitations will be determined. Finally, Component 3 will place considerations of genetics and physiology of C:N:P and growth in an ecological context by sampling a wide range of ecosystem types (lake, desert, grassland, forest) for key stoichiometric parameters. The main goal in these studies is to determine whether the C:N:P stoichiometry of primary producer and detritus biomass is associated with particular patterns of primary consumer biomass, C:N:P, and diversity.

Kuang
0077790
All organisms are composed of multiple chemical elements
such as carbon, nitrogen, and phosphorus. Recent research in the
area known as ecological stoichiometry has highlighted the
ecological importance of the relative abundance of chemical
constituents, known to vary considerably among species and across
trophic levels. However, most theoeretical studies in ecology
have until very recently ignored the sources and consequences of
this chemical heterogeneity. The investigator and his colleagues
undertake theoretical investigations of ecological stoichiometry.
They develop a relatively new theoretical framework for
ecological dynamics that explicitly incorporates stoichiometric
constraints. This base model involves a stoichiometric
counterpart of the familiar Rosenzweig-MacArthur equations in
which the effective carrying capacity of the resource species and
the transfer efficiency of the consumer species are constrained
by stoichiometric principles. Introduction of stoichiometric
considerations in these equations (here, akin to "food quality")
allows for a rich array of ecologically realistic dynamics,
including deterministic extinction of the consumer species when
resources are abundant but of poor quality. They expand this
model in five different directions, to explore ecological
realities (i.e., complications) whose consideration has proved
illuminating in other, non-stoichiometric settings. Specifically,
they analyze the dynamics of 1) a multi-nutrient model; 2)
trophically complex models in which multiple consumer species
share a resource; 3) time delays in nutrient recycling that are a
realistic component of terrestrial ecosystems; 4) two patch
models featuring habitat heterogeneity and dispersal of the
consumer; and 5) age structured models in which juvenile and
adult consumers differ in their nutrient requirements. The
project aims to provide an analytically rigorous foundation for
burgeoning empirical research into ecological stoichiometry.
All living things, including humans, are constructed of
approximately the same set of basic building blocks, chemical
elements such as carbon (C), nitrogen (N), phosphorus (P), and
several dozen more in smaller amounts. However, different
organisms contain different proportions of these key elements in
their biomass and thus must extract these elements from their
environment to differing degrees. In many situations, the
environment does not provide these key nutrient elements in the
abundance and proportions that are optimal for organism growth
and reproduction. Thus, the chemical environment of life may set
limits on the success of organisms in various situations. In this
project the investigators use mathematical models to simulate the
flow of multiple chemical elements in natural food webs to better
understand how the requirements of living things for multiple
chemical elements establish key feedbacks between the living and
non-living world. This work is important for two reasons. First,
it may provide a better fundamental understanding of how chemical
elements move through food webs. Second, improved fundamental
knowledge of how nutrients move in the environment and how to
simulate those movements with mathematical tools may help predict
and manage natural and human-dominated ecosystems, including
those affected by nutrient inputs from human activities (e.g. N
and P inputs from fertilizer, sewage) or by global change (e.g.
effects of increased atmospheric carbon dioxide on C and nutrient
flow in the environment).

0228894
Elser


This is a U.S.-China joint workshop proposed by Dr. James Elser, Arizona State University, on ecological complexity and ecosystem services. The workshop will bring together American and Chinese researchers in biocomplexity and ecosystem services in a series of interactions designed to establish a network of international collaboration and exchange. A preliminary meeting between U.S. and Chinese organizers will be held in November, 2002, and a U.S. delegation of 12 scientists will visit China in spring, 2003.

The intellectual merit of this proposal is outstanding. The area of ecosystem services is emerging as a topic for fundamental research. The proposed collaborative activities would benefit ecological science and its contribution to the management of complex ecological/economic systems. The Chinese Academy of Sciences, the National Natural Science Foundation of China, and NSF will jointly support the cooperative activities.

An interdisciplinary team of investigators carry out an
undergraduate training initiative at Arizona State University.
The training plan intimately combines new cross-disciplinary
courses and summer research programs. The former are constructed
to allow maximal participation among undergraduate cadres, and
facilitate life science majors to achieve a minor in mathematics,
and, likewise, mathematics majors to enrich their education with
a minor in bioscience. The summer research program is a
competitive enterprise involving at least eight ASU faculty
members from life sciences, mathematics, and biophysics.
Research projects span modeling of ecological and evolutionary
processes through the new lens of stoichiometric constraints,
bio-economics, chemostat theory, and modeling of visual
perception.

This project has potential to make broad impact in both
local and global education environs. Regarding the former, the
ASU UBM team is truly interdisciplinary, with members in
mathematics, biology and biophysics, exceptionally well suited
for interdisciplinary training for undergraduates in biological
and mathematical sciences. Its collaborative efforts can provide
undergraduate and graduate students of diverse ethnic/racial
backgrounds with first-hand educational experience in
cross-disciplinary communication and exploration. As for global
impact, the proposed holistic approach (involving mathematical
biology courses at various levels and summer research projects)
in mathematical biology training can vertically integrate all the
components in the ASU education system. It is therefore expected
that this proposed program may yield many invaluable lessons to
serve mathematical bioscience education and research nationwide,
enriching the experience for the next generation of students in
this integrative and interdisciplinary scientific endeavor.

Abstract

Awards: DMS 0342388, 0342239, 0342325
Principal Investigators: Yang Kuang, Val Smith, Marilyn S. Smith

This multi-campus team is studying processes within a single
biological host that can be described by models inspired by ecological
stoichiometry, the study of the balance of energy and multiple
chemical resources (usually elements) in ecological
interactions. These concepts have been broadened by their extension to
biological stoichiometry, which has proven to be an important new lens
through which we can view and understand complex biological
interactions. Within this general theory, the cycling and utilization
of energy and multiple nutrients by organisms and their constituent
cells occupies a central position. With its emphasis on the flow of
elemental matter, such as carbon, nitrogen, and phosphorus,
stoichiometric theory covers multiple biological scales. It also
allows, via rigid physical and chemical constraints, the construction
of robust mechanistic and predictive models. Originally formulated and
verified in the fields of limnology and plant ecology, biological
stoichiometry has recently been applied at physiological scales to
such diverse areas as organism development and tumor growth. In this
proposal we aim to synthesize and apply theoretical and empirical
approaches to biological stoichiometry within the grand framework of
internal disease. Recent headline-grabbing findings that connect
nutritional factors to disease dynamics indicate there is an
increasing need for stoichiometry-based mathematical models of
internal disease that track the effects of potentially limiting
resources. The proposed work weaves together threads of theoretical
and experimental research. Our primary aim is the construction of
predictive and verifiable theoretical models which can begin to
explicitly deal with the effects of stoichiometric interactions in
within-host disease dynamics. Such models will be built in a modular
fashion, starting with simple deterministic models, and then
progressively adding stochasticity, spatial heterogeneity, and
genetics. At each step the models will be challenged, calibrated, and
tested by in vitro laboratory experiments.

The proposed work will have a broad impact in both science research
and education, and eventually in internal disease management and
treatment. Regarding the former, our research team is truly
interdisciplinary, with group members in mathematics, theoretical
physics, ecology, and biomedicine. Our collaborative efforts will
provide undergraduate and graduate students and junior scientists of
diverse ethnic/racial backgrounds with first-hand educational
experience in cross-disciplinary communication and exploration. The
current proposal is a step towards new ways to understand disease,
aiming to develop robust and experimentally calibrated mathematical
theories of disease-host interactions that can be applied to a wide
variety of diseases. We firmly believe that such theories have a
central role to play in present and future research. These grants for
proposals submitted as a collaborative proposal from three
institutions are made under the Joint DMS/NIGMS Initiative to Support
Research Grants in the Area of Mathematical Biology. This is a joint
competition sponsored by the Division of Mathematical Sciences and the
Directorate for Biological Sciences at the National Science Foundation
and the National Institute of General Medical Sciences (NIGMS) at the
National Institutes of Health.

The important plant nutrient, nitrogen (N), can be transported in the atmosphere and deposited into terrestrial and aquatic habitats in rainfall. During recent decades, N deposition has greatly increased as a result of human activities, largely due to expansion of fertilizer application and of formation of nitrates (NO3) during fossil fuel burning. This study will try to determine if N deposition affects lake food webs by changing the chemical composition of the microscopic plants (phytoplankton) that form the base of lake food webs. Specifically, these investigators hypothesize that increasing inputs of N to lakes cause the phytoplankton to become strongly limited by another key element, phosphorus (P). When P-limited, phytoplankton produce biomass that has a very low P content and thus potentially become nutritionally unsuitable for growth of the next feeding level, the zooplankton. (Zooplankton, in turn, provide an important food base for fish, including those that are involved in recreational and commercial fisheries.) To test this, these researchers will measure P limitation of zooplankton growth in lakes receiving different levels of N deposition in central Colorado and in southern Norway. These investigators will also perform a larger scale field study that deliberately manipulates N inputs to experimental mesocosms deployed in a lake that receives low N deposition under normal conditions. This study will help in basic understanding of how lake food webs work while also providing potentially important information about an indirect but potentially important impact of human activity on seemingly pristine ecosystems and the food webs they support.

Elser
0527347



This is phase 2 of a US-China joint workshop on ecological complexity and ecosystem services. The first phase of exchange between U.S. and Chinese scientists took place on May 22 and June 7, 2004. Thirteen American scientists plus two program officers engaged in a series of intellectual interactions in China with Chinese scientists interested in studying the complex connections between ecological systems and human societies. The purpose of phase 2 of this workshop is to solidify the connections established during the phase 1 visit and to provide an opportunity for Chinese scientists to have a similar transformative experience with respect to better understanding the situation in the USA. This workshop addresses important topics with global relevance and significance. Results from the proposed meetings have the potential to improve the quality of life for Earth's inhabitants, and the sustainability of natural resources and ecosystems and the benefits and services they provide. This project is jointly supported by the Chinese Academy of Sciences, the National Science Foundation of China, and the NSF.

Global sustainability and human prosperity ultimately depend on biodiversity and ecosystem services that result from ecological functions such as primary productivity and nutrient cycling. With accelerating biodiversity loss worldwide, it is critically important to understand how biodiversity and ecosystem functioning (BEF) are related. However, current knowledge is incomplete because almost all BEF studies so far have been conducted in artificial grasslands, focusing solely on plants. This project will directly manipulate plant diversity in large-scale experimental plots and measure a number of ecosystem function variables to test existing BEF and evaluate new hypotheses regarding ecosystem function for multiple trophic levels (plants, herbivores, and soil microbes) in the Inner Mongolian Grassland, part of the largest natural grassland in the world.

This study will permit a better assessment of potential impacts of future global and local biodiversity loss. It will also improve management practices for arid and semi-arid ecosystems. The project will provide exceptional educational, cultural, and research experiences for US and Chinese scientists and students, and contribute to the development of a globally engaged workforce. Finally, it will help establish a long-term scientific platform in the Inner Mongolia Grassland for US-China collaborations on ecological research and sustainability science.

Organisms are composed of chemical elements such as carbon, hydrogen, oxygen, nitrogen, and phosphorus. Research in the area known as ecological stoichiometry (ES) has highlighted the ecological importance of the relative abundance of chemical constituents, known to vary considerably among species and across trophic levels. ES deals with how the balance of energy and elements affect and are affected by organisms and their interactions in ecosystems. It has proven to be an important new lens through which to view and understand ecological interactions and has gained momentum by explicitly linking the elemental physiology of organisms to their food web interactions and ecosystem function. Thus, ES theory covers multiple biological scales and allows, via rigid physical and chemical constraints, the construction of robust mechanistic and predictive mathematical models. While biology has a research tradition that is empirical in nature and often only weakly connected to formal quantitative analyses, mathematical and theoretical biology on the other hand has had a research agenda that has often been somewhat distanced from mainstream empirical biology. There is not enough effort and attention on marrying empirical results with theoretical findings. The investigators will extend and generalize existing well-received stoichiometry-based mathematical models to encompass a broader range of ecological situations, including cell quota dynamics, consumer age- or size-structures, variable consumer stoichiometry, and delayed nutrient cycling. Once such a generalized theoretical framework is established, the investigators will construct and evaluate models inspired by recent empirical discoveries in ES, including one considering the effects on consumer dynamics of not only insufficient food nutrient content but also of excess food nutrient content, and another considering the effects of stoichiometric dietary mixing. Finally, the investigators will challenge these parameterized stoichiometric models against observed population growth dynamics qualitatively and quantitatively. In doing so, the investigators hope to achieve a far-reaching synthesis between model and experiment in the form of new theoretical applications that may allow for direct and quantitative predictions of the effects of stoichiometric constraints on ecosystem processes. The models the investigators will investigate may motivate challenging but tractable problems in areas of qualitative and computational studies of nonlinear differential equations and delay differential equations.

This project will have a broad impact in both local and global environs. The biological findings of this project may have a number of practical applications to issues such as eutrophication, biofuel production, global change, and biodiversity. Its theoretical outcomes will provide a solid and user-friendly framework to build mathematical models that allow quantitative prediction of ecological interactions. Moreover, it will find many ready applications in cancer and other within host diseases dynamics and treatment modeling since one can view cancer cells and pathogens as invading species in a host ecosystem. The investigators' collaborative efforts will provide undergraduate and graduate students of diverse ethnic/racial backgrounds with first-hand educational experience in cross-disciplinary communication and exploration. Finally, the investigators are partnering with Arizona State University's School of Life Sciences award-winning Ask-A-Biologist program to develop articles and virtual experiments related to this project to enhance middle- and high school student learning of biological and mathematical concepts.

This Doctoral Dissertation Enhancement award will support field research on grasshopper migration in China by Ph.D. student Arianne Cease of Arizona State University. Several specific questions will be addressed in this research including: 1) Do migratory forms of grasshopper result from superior or inferior diet quality? 2) Can transitions between migratory and nonmigratory forms be triggered by changes in specific plant characteristics, such as nitrogen, carbon, phosphorus, or alkaloid content? 3) Does overgrazing stimulate formation of migratory forms by lowering plant nutritional quality? To address these questions, the density and diet of Oedaleus asiaticus will be manipulated in the lab and observed in the field, and morphological, physiological and behavioral responses of developing grasshoppers will be recorded. This award will promote a highly interdisciplinary collaboration by a group of NSF-funded ecologists and insect physiologists with grasshopper biologists and grassland botanists in China. Collaborative activities funded by this award will include research at the Beijing Institute of Life Sciences and the State Key Laboratory of Integrated Management of Insect & Rodent Pests involving multiple Chinese and US scientists. Finally, this research will provide critical data necessary to understand and potentially prevent disastrous locust swarms.

During an outbreak year, swarming grasshoppers (locusts) can populate 11 million square miles of land worldwide, negatively affecting more than 60 countries and the livelihood of 1 out of every 10 people. Global climate change is predicted to increase precipitation variability and perhaps exacerbate locust outbreaks. While it is often hypothesized that dietary cues related to deteriorating environmental conditions might trigger locust swarms, the specific dietary cues that may cause this developmental plasticity are unknown. This research will investigate the question in China, using the grasshopper O. asiaticus, one of two economically important outbreak locusts in Asia. This research will also establish long-term international research ties and promote a globally engaged scientific workforce focused on an important agricultural problem.

All organisms require chemical elements such as carbon (C), nitrogen (N), and phosphorus (P) for growth and development. P is of particular interest because it is especially important in construction of genetic material such as DNA and RNA and is often present in limiting concentrations in the environment. This project will investigate the biological rules that determine the elemental recipe ("stoichiometry") of microorganisms that grow under severely P deficient conditions in a set of unique desert springs in Mexico.

This study will use both laboratory and field experiments, combined with cutting-edge methods of molecular biology and genomics, to investigate how changes in P supply alter the ecological and evolutionary dynamics of these microorganisms and to reveal how they cope with shortages of this essential chemical element. Furthermore, the study will help us understand how human alterations in P supply, such as those driven by inefficient use of fertilizer or by inputs of P-rich sewage, affect microbial ecosystems. It will also help in discovery of new genes and genetic strategies by which organisms efficiently use P. These discoveries may be useful for agriculture and other settings in light of growing concern about the finite supply of economically recoverable P for fertilizer production. Finally, the project will produce bi-lingual science education products that will enhance science education in Arizona and nationally for both K/12 students and the general public.

Steering Committee: James Elser, Rimjhim Aggarwal, and Helen Rowe at Arizona State University;
Tauhidur Rahman, University of Arizona; David Vaccari, Stephens Institute of Technology; Anita
Street, US Department of Energy; Robert Mikkelsen, International Plant Nutrition Institute

Intellectual Merit: Phosphorus (P) is an essential element to life and, with few exceptions, a necessary
fertilizer for high agricultural yield. Because P cannot be manufactured and global supply is limited,
this chemical element poses a unique, double-sided threat to sustainability. P scarcity leads to
high prices and poverty for poor farmers in developing countries, but in industrialized nations, excess
P from farms and in urban waste streams degrades downstream water quality. The issues surrounding
P sustainability are deeply complex and involve diverse geological, biogeochemical, economic, and
geopolitical dimensions that are currently unconsolidated. Environmental degradation due to nutrient
runoff and potential threats to global food security urgently call for an end to this disjointed approach
to phosphorus. The goal of the P Sustainability Research Coordination Network (RCN) is to spark an
interdisciplinary synthesis of data, perspectives, and understanding about phosphorus to identify and
implement solutions for P sustainability.

The RCN theme, objectives, and initial topics build upon broad agreement on key P sustainability
challenges reached at a recent Sustainable P Summit (SPS) led by James Elser and colleague Dan Childers.
The RCN will involve two phases centered on three Challenge Areas. Phase I groups will work
on two Challenges: (1) Improving P efficiency in food production; (2) Developing robust pathways
of P recycling. At the Kick-off Workshop, identified Core Members will develop Working Groups
centered around these challenge areas. These Groups will be further populated with At-Large Members
recruited through a widely advertised application process that will allow us to target qualified
graduate students, postdocs, and members of under-represented groups. In Year 3, a Synthesis Workshop
will report on the science and solution outcomes from Phase I and develop new Phase II Working
Groups focused on Challenge 3: Integrating efficiency and recycling to create a sustainable food system.
A Wrap-up Workshop, held early in Year 5, will be held to report on science and solution outcomes
from Phase II and provide the push to finalize outcomes.

Broader Impacts: Central to the P Sustainability RCN will be recruitment of a diverse network of
participants of different professions, ranks, genders, races, ethnicities, and nationalities. The Steering
Committee will reflect this diversity, including three students in ex officio capacity, giving them invaluable
experience in leadership, networking, collaborative science, and policy. To communicate key
aspects of RCN work, we will produce two dynamic, high-quality videos to reach targeted audiences of
farmers, educators, fertilizer industry, and policy makers. The three RCN Workshops will be held in
Washington DC in order to facilitate participation by policy makers, government officials, representatives
of agriculture and the fertilizer industry, and urban planners with the aim of developing research priorities
for the RCN, presenting outcomes and planning implementation of sustainability solutions.

Research has recently shown that overgrazing of livestock in a grassland in China lowered the nitrogen content of the grasses and that this caused a rise in the abundance of a locust likely to lead to locust swarms. This proposal will test whether this is also true for related species of locust in Australia and western Africa, and link both grazing practices and locust swarms to economics and social policy in the three contrasting regions. Three biologists and three social scientists will team up to help answer: (1) How do insect-nutrient relations and livestock grazing strategies interact to affect food prices, food security, and rangeland degradation? (2) How do property rights regimes affect the adaptive capacity of societies to respond to the link between overgrazing and locust outbreaks? Because both market forces and locust swarms operate over long distances, these effects are likely to be global.

Locust outbreaks have had devastating effects on food security, impacting crop and livestock yields. This proposal aims to develop new, sustainable strategies to understand and manage locust outbreaks, accounting for feedbacks among ecological, agricultural, and economic systems. Results will be translated directly into management and policy recommendations through collaborations with agricultural agencies. The project will also strengthen international scientific collaboration, train undergraduate and graduate students, and develop a multi-media outreach program for K-12 students and teachers.