Life Sciences Commons^™

Regeneration Strategies And Forest Resilience To Changing Fire Regimes: Insights From A Goldilocks Model, Tanjona Ramiadantsoa, Zak Ratajczak, Monica G. Turner

Aspen Bibliography

Disturbances are ubiquitous in ecological systems, and species have evolved a range of strategies to resist or rebound following disturbance. Understanding how the presence and complementarity of regeneration traits will affect community responses to disturbance is increasingly urgent as disturbance regimes shift beyond their historical ranges of variability. We define "disturbance niche" as a species' fitness across a range of disturbance sizes and frequencies that can reflect the fundamental or realized niche, that is, whether the species occurs alone or with other species. We developed a model of intermediate complexity (i.e., a Goldilocks model) to infer the disturbance niche. We …

Pando's Pulse: Vital Signs Signal Need For Course Correction At World-Renowned Aspen Forest, Paul C. Rogers

Aspen Bibliography

Upland aspen (Populus spp.) forests contribute significantly to biodiversity in their circumboreal role as keystone species. As aspen ecosystems flourish or diminish, myriad dependent species follow suit. The 43-hectare Pando aspen (Populus tremuloides Michx.) clone in Utah, USA, is thought to be the largest living organism on earth, but is faltering due to chronic herbivory. Long-term resilience in aspen communities, including Pando, rests on successful recruitment of vegetative suckers that are nutritiously desirable to browsing ungulates. Here, I evaluate aspen reproduction alongside numerous vital indicators of Pando's status in the first trend assessment of this embattled iconic forest. …

Biodiversity And Foraging Preferences Of Bee Communities At Pinnacles National Park Over Time, Abigail M. E. Lehner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Bees are considered to be the most important animal pollinator, providing billions of dollars in pollination services each year. Despite their importance in both natural and agricultural settings, the status of most native bees is unknown. Native bees are subject to a variety of threats including habitat loss, pesticide use, and climate change. Yet, monitoring programs have been implemented in few natural areas. Pinnacles National Park, PNP, in California is one of the only natural areas to have a large historical dataset on bees across decades with surveys conducted in 1996, 1997, 1998, 1999, 2002, 2011, and 2012. These surveys …

Hidden Mechanisms Of Climate Impacts In Western Forests: Integrating Theory And Observation For Climate Adaptation, Sara J. Germain

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Fire, insects, and disease are necessary components of forest ecosystems. Yet, climate change is intensifying these tree stressors and creating new interactions that threaten forest survival. This dissertation combined field observations with statistical predictions of changing disturbances in western forests to identify 1) how conventional models may underestimate future forest loss, and 2) how positive relationships between trees may be exploited by managers to prevent forest loss.

In Chapter II, I tested whether increasingly extreme weather with climate change increases Pacific yew extinction risk. I found that conventional modeling methods underestimated local extinction risk because trees were adapted to a …

Detection Of European Aspen (Populus Tremula L.) Based On An Unmanned Aerial Vehicle Approach In Boreal Forests, Anton Kuzmin, Lauri Korhonen, Sonja Kivinen, Pekka Hurskainen, Pasi Korpelainen, Topi Tanhuanpää, Matti Maltamo, Petteri Vihervaara, Timo Kumpula

Aspen Bibliography

European aspen (Populus tremula L.) is a keystone species for biodiversity of boreal forests. Large-diameter aspens maintain the diversity of hundreds of species, many of which are threatened in Fennoscandia. Due to a low economic value and relatively sparse and scattered occurrence of aspen in boreal forests, there is a lack of information of the spatial and temporal distribution of aspen, which hampers efficient planning and implementation of sustainable forest management practices and conservation efforts. Our objective was to assess identification of European aspen at the individual tree level in a southern boreal forest using high-resolution photogrammetric point cloud …

General Destabilizing Effects Of Eutrophication On Grassland Productivity At Multiple Spatial Scales, Yann Hautier, Pengfei Zhang, Michel Loreau, Kevin R. Wilcox, Eric W. Seabloom, Elizabeth T. Borer, Jarrett E.K. Byrnes, Sally E. Koerner, Kimberly J. Komatsu, Jonathan S. Lefcheck, Andy Hector, Peter B. Adler, Juan Alberti, Carlos A. Arnillas, Jonathan D. Bakker, Lars A. Brudvig, Miguel N. Bugalho, Marc Cadotte, Maria C. Caldeira, Oliver Carroll, Mick Crawley, Scott L. Collins, Pedro Daleo, Laura E. Dee, Nico Eisenhauer, Anu Eskelinen, Philip A. Fay, Benjamin Gilbert, Amandine Hansar, Forest Isbell, Johannes M.H. Knops, Andrew S. Macdougall, Rebecca L. Mcculley, Joslin L. Moore, John W. Morgan, Akira S. Mori, Pablo L. Peri, Edwin T. Pos, Sally A. Power, Jodi N. Price, Peter B. Reich, Anita C. Risch, Christiane Roscher, Mahesh Sankaran, Martin Schütz, Melinda Smith, Carly Stevens, Pedro M. Tognetti, Risto Virtanen, Glenda M. Wardle, Peter A. Wilfahrt, Shaopeng Wang

Wildland Resources Faculty Publications

Eutrophication is a widespread environmental change that usually reduces the stabilizing effect of plant diversity on productivity in local communities. Whether this effect is scale dependent remains to be elucidated. Here, we determine the relationship between plant diversity and temporal stability of productivity for 243 plant communities from 42 grasslands across the globe and quantify the effect of chronic fertilization on these relationships. Unfertilized local communities with more plant species exhibit greater asynchronous dynamics among species in response to natural environmental fluctuations, resulting in greater local stability (alpha stability). Moreover, neighborhood communities that have greater spatial variation in plant species …

Spatial And Temporal Dynamics Of Human–Wildlife Conflicts In The Kenya Greater Tsavo Ecosystem, Joseph M. Mukeka, Joseph O. Ogutu, Erustus Kanga, Eivin Røskaft

Human–Wildlife Interactions

Biodiversity conservation in developing countries is faced with many and mounting challenges, including increasing human–wildlife conflicts (HWCs). In Africa and other developing countries, increasing HWCs, particularly those adjacent to protected areas, can adversely affect local stakeholder perceptions and support for conservation. We analyzed HWC reports for multiple wildlife species compiled >23 years (1995–2017) from the Greater Tsavo Ecosystem (GTE) in Kenya to determine HWC trends. The GTE is the largest protected area in Kenya, covering 22,681 km². Overall, 39,022 HWC incidents were reported in 6 GTE regions (i.e., Taveta, Mutomo, Kibwezi, Rombo, Galana, Bachuma). The 5 wildlife species …

Investigating The Direct And Indirect Effects Of Forest Fragmentation On Plant Functional Diversity, Jenny Zambrano, Norbert J. Cordeiro, Carol Garzon-Lopez, Lauren Yeager, Claire Fortunel, Henry J. Ndangalasi, Noelle G. Beckman

Biology Faculty Publications

Ongoing habitat loss and fragmentation alter the functional diversity of forests. Generalising the magnitude of change in functional diversity of fragmented landscapes and its drivers is challenging because of the multiple scales at which landscape fragmentation takes place. Here we propose a multi-scale approach to determine whether fragmentation processes at the local and landscape scales are reducing functional diversity of trees in the East Usambara Mountains, Tanzania. We employ a structural equation modelling approach using five key plant traits (seed length, dispersal mode, shade tolerance, maximum tree height, and wood density) to better understand the functional responses of trees to …

Past Management Spurs Differential Plant Communities Within A Giant Single-Clone Aspen Forest, Paul C. Rogers, Jan ŠEbesta

Ecology Center Publications

Sustainable aspen ecosystems hold great promise for global biodiversity conservation. These forests harbor relatively high species diversity, yet are threatened by fire suppression, land development, timber-focused management, extended droughts, and chronic herbivory. “Pando” is a high-profile quaking aspen (Populus tremuloides) forest in Utah, USA which is putatively the ‘largest living organism on earth.’ Pando comprises an estimated 47,000 genetically identical stems, but is threatened by human impacts. Our interest in the present study is whether changes to the giant organism were affecting understorey vegetation and whether discrete zones are displaying divergent community compositions. For instance, recent research has demonstrated strong …

Variations In Tetrodotoxin Levels In Populations Of Taricha Granulosa Are Expressed In The Morphology Of Their Cutaneous Glands, Pedro Luiz Mailho-Fontana, Carlos Jared, Marta Maria Antoniazzi, Juliana Mozer Sciani, Daniel Carvalho Pimenta, James P. Strange, Taran Grant, Edmund D. Brodie Jr., Edmund D. Brodie Jr.

Biology Faculty Publications

Tetrodotoxin (TTX), one of the most toxic substances in nature, is present in bacteria, invertebrates, fishes, and amphibians. Marine organisms seem to bioaccumulate TTX from their food or acquire it from symbiotic bacteria, but its origin in amphibians is unclear. Taricha granulosa can exhibit high TTX levels, presumably concentrated in skin poison glands, acting as an agent of selection upon predatory garter snakes (Thamnophis). This co-evolutionary arms race induces variation in T. granulosa TTX levels, from very high to undetectable. Using morphology and biochemistry, we investigated differences in toxin localization and quality between two populations at the extremes …

A Global View Of Aspen: Conservation Science For Widespread Keystone Systems, Paul C. Rogers, Bradley D. Pinno, Jan Šebesta, Benedicte R. Albrectsen, Guoqing Li, Natalya Ivanova, Dominik Kulakowski, Antonín Kusbach, Timo Kuuluvainen, Simon M. Landhäusser, Hongyan Liu, Tor Myking, Pertti Pulkkinen, Zhongming Wen

Ecology Center Publications

Across the northern hemisphere, six species of aspen (Populus spp.) play a disproportionately important role in promoting biodiversity, sequestering carbon, limiting forest disturbances, and providing other ecosystem services. In many regions, aspen can maintain canopy dominance for decades to centuries as the sole major broadleaf trees in forested landscapes otherwise dominated by conifers. Aspen ecosystems are valued for many reasons, but here we highlight their potential as key contributors to regional and global biodiversity. We begin with an overview of the aspens’ ecological and economic roles. We then present a systematic literature analysis to assess topics of aspen …

Biodiversity Within Aspen Forests, Paul C. Rogers

Aspen Bibliography

Aspen have long been known for supporting lush vegetation and rich wildlife habitat. These features, alongside brilliant green and gold seasonal coloration, accompany a broadly appreciated aesthetic for aspen forests by the public-at-large. However, in earlier times timber producers in many locales considered aspen to have low value and actively eliminated them. More recent research has pointed out that relative moisture held within aspen communities facilitates a wide array of species – collectively, biodiversity – compared to surrounding vegetation types. Aspen groves in the Intermountain West, for example, are known to be second only to riparian forests is supporting the …

Geospatial Modeling Of Land Cover Change In The Chocó-Darien Global Ecoregion Of South America; One Of Most Biodiverse And Rainy Areas In The World, José Camilo Fagua, R. Douglas Ramsey

Ecology Center Publications

The tropical rain forests of northwest South America fall within the Chocó-Darien Global Ecoregion (CGE). The CGE is one of 25 global biodiversity hotspots prioritized for conservation due to its high biodiversity and endemism as well as threats due to deforestation. The analysis of land-use and land-cover (LULC) change within the CGE using remotely sensed imagery is challenging because this area is considered to be one of the rainiest places on the planet (hence high frequency of cloud cover). Furthermore, the availability of high-resolution remotely sensed data is low for developing countries before 2015. Using the Random Forest ensemble learning …

Weighting Effective Number Of Species Measures By Abundance Weakens Detection Of Diversity Responses, Yong Cao, Charles P. Hawkins

Ecology Center Publications

1. The effective number of species (ENS) has been proposed as a robust measure of species diversity that overcomes several limitations in terms of both diversity indices and species richness (SR). However, it is not yet clear if ENS improves interpretation and comparison of biodiversity monitoring data, and ultimately resource management decisions.

2. We used simulations of five stream macroinvertebrate assemblages and spatially extensive field data of stream fishes and mussels to show (a) how different ENS formulations respond to stress and (b) how diversity–environment relationships change with values of q, which weight ENS measures by species abundances.

3. Values …

Decades Of Native Bee Biodiversity Surveys At Pinnacles National Park Highlight The Importance Of Monitoring Natural Areas Over Time, Joan M. Meiners, Terry L. Griswold, Olivia Messinger Carril

All PIRU Publications

Thousands of species of bees are in global decline, yet research addressing the ecology and status of these wild pollinators lags far behind work being done to address similar impacts on the managed honey bee. This knowledge gap is especially glaring in natural areas, despite knowledge that protected habitats harbor and export diverse bee communities into nearby croplands where their pollination services have been valued at over $3 billion per year. Surrounded by ranches and farmlands, Pinnacles National Park in the Inner South Coast Range of California contains intact Mediterranean chaparral shrubland. This habitat type is among the most valuable …

Effectiveness Of Snap And A24-Automated Traps And Broadcast Anticoagulant Bait In Suppressing Commensal Rodents In Hawaii, Aaron B. Shiels, Tyler Bogardus, Jobriath Rohrer, Kapua Kawelo

Human–Wildlife Interactions

Commensal rodents (invasive rats, Rattus spp.; house mice, Mus musculus) are well established globally. They threaten human health by disease transfer and impact economies by causing agricultural damage. On island landscapes, they are frequent predators of native species and affect biodiversity. To provide managers with better information regarding methods to suppress commensal rodent populations in remote island forests, in 2016 we evaluated the effectiveness of continuous rat trapping using snap-traps, Goodnature^®A24 self-resetting rat traps, and a 1-time (2-application) hand-broadcast of anticoagulant rodenticide bait pellets (Diphacinone-50) applied at 13.8 kg/ha per application in a 5-ha forest on Oahu, …

Reducing Protected Lands In A Hotspot Of Bee Biodiversity: Bees Of Grand Staircase-Escalante National Monument, Joseph S. Wilson, Matt Kelly, Olivia Messinger Carril

Biology Faculty Publications

Grand Staircase-Escalante National Monument is a federally protected area found in central southern Utah. Designated in 1996 by President William J. Clinton, it was recently reduced in size by President Donald J. Trump in a proclamation that turned the one large monument into three smaller ones. A long-term, standardized study of the bees had been conducted from 2000–2003, revealing 660 species. The bee communities of the area are characterized by being spatially heterogeneous; most of the bees occur in isolated areas, with only a few being both abundant and widespread. Here we examine what affect the recent resizing of the …

How Behavior Of Nontarget Species Affects Perceived Accuracy Of Scat Detection Dog Surveys, Karen E. Dematteo, Linsey W. Blake, Julie K. Young, Barbara Davenport

Wildland Resources Faculty Publications

Detection dogs, specially trained domestic dogs (Canis familiaris), have become a valuable, noninvasive, conservation tool because they remove the dependence of attracting species to a particular location. Further, detection dogs locate samples independent of appearance, composition, or visibility allowing researchers to collect large sets of unbiased samples that can be used in complex ecological queries. One question not fully addressed is why samples from nontarget species are inadvertently collected during detection dog surveys. While a common explanation has been incomplete handler or dog training, our study aimed to explore alternative explanations. Our trials demonstrate that a scat’s genetic …

Multiple Facets Of Biodiversity Drive The Diversity-Stability Relationship, Dylan Craven, Nico Eisenhauer, William D. Pearse, Yann Hautier, Christiane Roscher, Forest Isbell, Michael Bahn, Carl Beierkuhnlein, Gerhard Bönisch, Nina Buchmann, Chaeho Byun, Jane A. Catford, Bruno E.L. Cerabolini, J. Hans C. Cornelissen, Joseph M. Craine, Enrica De Luca, Anne Ebeling, John N. Griffin, Andy Hector, Jes Hines, Anke Jentsch, Jens Kattge, Jürgen Kreyling, Vojtech Lanta, Nathan Lemoine, Sebastian T. Meyer, Vanessa Minden, Vladimir Onipchenko, H. Wayne Polley, Peter B. Reich, Jasper Van Ruijven, Brandon Schamp, Melinda D. Smith, Nadejda A. Soudzilovskaia, David Tilman, Alexandra Weigelt, Brian Wilsey, Peter Manning

Biology Faculty Publications

A significant body of evidence has demonstrated that biodiversity stabilizes ecosystem functioning over time in grassland ecosystems. However, the relative importance of different facets of biodiversity underlying the diversity–stability relationship remains unclear. Here we used data from 39 biodiversity experiments and structural equation modeling to investigate the roles of species richness, phylogenetic diversity, and both the diversity and community-weighted mean of functional traits representing the ‘fast–slow’ leaf economics spectrum in driving the diversity–stability relationship. We found that high species richness and phylogenetic diversity stabilize biomass production via enhanced asynchrony. Contrary to our hypothesis, low phylogenetic diversity also enhances ecosystem stability …

Prioritizing Phylogenetic Diversity Captures Functional Diversity Unreliably, Florent Mazel, Matthew W. Pennell, Marc W. Cadotte, Sandra Diaz, Giulio Valentino Dalla Riva, Richard Grenyer, Fabien Leprieur, Arne O. Mooers, David Mouillot, Caroline M. Tucker, William D. Pearse

Biology Faculty Publications

In the face of the biodiversity crisis, it is argued that we should prioritize species in order to capture high functional diversity (FD). Because species traits often reflect shared evolutionary history, many researchers have assumed that maximizing phylogenetic diversity (PD) should indirectly capture FD, a hypothesis that we name the “phylogenetic gambit”. Here, we empirically test this gambit using data on ecologically relevant traits from >15,000 vertebrate species. Specifically, we estimate a measure of surrogacy of PD for FD. We find that maximizing PD results in an average gain of 18% of FD relative to random choice. However, this average …

Competition And Coexistence In Plant Communities: Intraspecific Competition Is Stronger Than Interspecific Competition, Peter B. Adler, Danielle Smull, Karen H. Beard, Ryan T. Choi, Tucker J. Furniss, Andrew Kulmatiski, Joan M. Meiners, Andrew T. Tredennick, Kari E. Veblen

Ecology Center Publications

Theory predicts that intraspecific competition should be stronger than interspecific competition for any pair of stably coexisting species, yet previous literature reviews found little support for this pattern. We screened over 5400 publications and identified 39 studies that quantified phenomenological intraspecific and interspecific interactions in terrestrial plant communities. Of the 67% of species pairs in which both intra‐ and interspecific effects were negative (competitive), intraspecific competition was, on average, four to five‐fold stronger than interspecific competition. Of the remaining pairs, 93% featured intraspecific competition and interspecific facilitation, a situation that stabilises coexistence. The difference between intra‐ and interspecific effects tended …

Checklist Of Bees (Hymenoptera: Apoidea) From Managed Emergent Wetlands In The Lower Mississippi Alluvial Valley Of Arkansas, Phillip L. Stephenson, Terry Griswold, Michael S. Arduser, Ashley P. G. Dowling, David G. Krementz

All PIRU Publications

Background

Here we present the results from a two-year bee survey conducted on 18 managed emergent wetlands in the lower Mississippi Alluvial Valley of Arkansas, USA. Sample methods included pan traps, sweep netting and blue-vane traps. We document 83 bee species and morphospecies in 5 families and 31 genera, of which 37 species represent first published state records for Arkansas. The majority of species were opportunistic wetland species; only a small number were wetland-dependent species or species largely restricted to alluvial plains.

New information

We present new distributional records for bee species not previously recorded in managed emergent wetlands and …

Human Observers Differ In Ability To Perceive Insect Diversity, Joseph S. Wilson, Joshua P. Jahner, Matthew L. Forister

Biology Faculty Publications

Human perception of biological variation is an important and understudied issue in the conservation and management of natural resources. Here, we took a novel approach by asking 1152 participants, primarily college biology students, to score examples of insect mimicry by the number of distinct kinds of animals they saw. Latent class analysis successfully separated participants based on their accuracy of perception as well as demographic information and opinions about biodiversity. Contrary to expectations, factors such as childhood experience (growing up in urban, suburban or rural areas) did not affect the ability to see biodiversity as much as political views (location …

Lichen Monitoring Delineates Biodiversity On A Great Barrier Reef Coral Cay, Paul C. Rogers, Roderick W. Rogers, Anne Hedrich, Patrick T. Moss

Wildland Resources Faculty Publications

Coral islands around the world are threatened by changing climates. Rising seas, drought, and increased tropical storms are already impacting island ecosystems. We aim to better understand lichen community ecology of coral island forests. We used an epiphytic lichen community survey to gauge Pisonia (Pisonia grandis R.BR.), which dominates forest conditions on Heron Island, Australia. Nine survey plots were sampled for lichen species presence and abundance, all tree diameters and species, GPS location, distance to forest-beach edge, and dominant forest type. Results found only six unique lichens and two lichen associates. A Multi-Response Permutation Procedures (MRPP) test found statistically distinct …

A Functional Framework For Improved Management Of Western North American Aspen (Populus Tremuloides Michx.), Paul C. Rogers, Simon M. Landhausser, Bradley D. Pinno, Ronald J. Ryel

Wildland Resources Faculty Publications

Quaking or trembling aspen (Populus tremuloides Michx.) forests occur in highly diverse setting across North America. However, management of distinct communities has long relied on a single aspen to-conifer successional model. We examine a variety of aspen dominated stand types in the western portion of its range as ecological systems; avoiding an exclusive focus on seral dynamics or single species management. We build a case for a large-scale functional aspen typology based on existing literature. Aspen functional types are defined as aspen communities that differ markedly in their physical and biological processes. The framework presented here describes two “functional types” …

Herbivory Strains Resilience In Drought-Prone Aspen Landscapes Of The Western United States, Paul C. Rogers

Aspen Bibliography

Aims: Aspen forests around the northern hemisphere provide rich biodiversity compared to surrounding vegetation types. In both North America and Europe, however, aspen are threatened by a variety of human impacts: clear-felling, land development, water diversions, fire suppression, and both wild and domestic ungulate herbivory. We conducted a landscape assessment of quaking aspen (Populus tremuloides) for the purpose of identifying key components of resilience. Specifically, we strove to test novel measures linking plant-animal interactions, compare crucial functional differences in aspen types, and make appropriate restorative recommendations based on the outcome of these assessments. Location: The Book Cliffs region of eastern …

Opposing Mechanisms Drive Richness Patterns Of Core And Transient Bird Species, Jessica R. Coyle, Allen H. Hurlbert, Ethan P. White

Biology Faculty Publications

Studies of biodiversity typically assume that all species are equivalent. However, some species in a community maintain viable populations in the study area, while others occur only occasionally as transient individuals. Here we show that North American bird communities can reliably be divided into core and transient species groups and that the richness of each group is driven by different processes. The richness of core species is influenced primarily by local environmental conditions, while the richness of transient species is influenced primarily by the heterogeneity of the surrounding landscape. This demonstrates that the well-known effects of the local environment and …

Ecological Effects Of Genotypic Diversity On Community And Ecosystem Function, Megan K. Kanaga

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Genotypic diversity within populations can have important evolutionary consequences, but the ecological effects of intraspecific genetic variation on community and ecosystem function have only been studied in a few systems. I present the results of a three-year study designed to address the ecological impacts of genotypic diversity in quaking aspen (Populus tremuloides Michx.), using aspen genotypes planted across genotypic diversity levels (monoculture and mixture) and watering treatment levels (well-watered and water-limited). First, I demonstrated that significant variation exists among genotypes for a wide range of growth, morphological and physiological traits, and quantified high heritability and coefficient of genetic variation …

Patch-Scale Effects Of An Invasive Ecosystem Engineer On The Structure And Function Of A Eutrophic Stream, Samuel J. Hochhalter

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Recent theoretical and technological advances in ecosystem science have dramatically expanded the ways in which scientists can pursue and explore ecological questions. For my thesis research, I integrated the recent theoretical concept of organisms as ecosystem engineers with the relatively recent development of stable isotope tracer tests to ask the question: how does the invasive common carp affect stream ecosystem structure and function? To investigate the structuring role of carp, I measured autotroph seasonal distribution and abundance and macroinvertebrate seasonal abundance and diversity within two stream reaches in Spring Creek, Utah, USA; one with low carp biomass (LCB) and one …

Growing Wild: Crested Wheatgrass And The Landscape Of Belonging, Lafe Gerald Conner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Crested wheatgrass arrived in North America at the turn of the twentieth century through the foreign plant exploration missions sponsored by the United States Department of Agriculture. During the first two decades of the new century, scientists tested the grass at agricultural experiment stations. They determined it was useful for grazing and particularly valuable because it could grow in drought conditions with little or no care and would continue to produce high quality feed even after several years of heavy use. Beginning in the 1930s federally sponsored land utilization and agricultural adjustment programs sponsored the use of crested wheatgrass for …