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Donald Schoolmaster, Ph.D.

Don Schoolmaster is an Ecologist at WARC in Lafayette, LA.

RESEARCH

Don Schoolmaster's research focuses on the use quatitiative tools to combine ecological theory and data to address important applied questions. Two major avenues his work takes is 1) Using theory in inform causal networks (such as structural equations) that can be tested with data. His work in this area included both the development of methods, such as advanced methods for Structural Equation Modeling (SEM) and applying these method to address ecological problems. 2) Using ecological theory to inform tools of ecological assessment. The methods used to develop quantitative tools such as Ecological Indicators (EI) and Multimetric Indices (MMI) often imply causal assumptions. The usefulness of the final assement tool will often depend critically on how well these assumptions are met. Schoolmaster works to develop quatitiative assement methods that have causal assumptions that are met by ecological theory and expert opinion to insure a match between the assessment tool and understanding of how the systems works. 

 

Science and Products

Filter Total Items: 18

A graphical causal model for resolving species identity effects and biodiversity–ecosystem function correlations

Identifying and clearly communicating the drivers of ecosystem function is a crucially important goal for both basic and applied ecology. This has proven difficult because the putative causes (e.g., environment, species identity, biodiversity, and functional traits) are numerous and correlated. The problem is exacerbated by a lack of a formal framework for unambiguously relating theoretical langua
By
Ecosystems, Wetland and Aquatic Research Center

Using maintenance records from a long-term sensor monitoring network to evaluate the relationship between maintenance schedule and data quality

Sensor-based environmental monitoring networks are beginning to provide the large-scale, long-term data required to address important fundamental and applied questions in ecology. However, the data quality from deployed sensors can be difficult and costly to ensure. In this study, we use maintenance records from the 12-year history of Louisiana’s Coastwide Reference Monitoring System (CRMS) to ass
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Ecosystems, Wetland and Aquatic Research Center

A causal partition of trait correlations: using graphical models to derive statistical models from theoretical language

Recent studies hypothesize various causes of species‐level trait covariation, namely size (e.g., metabolic theory of ecology and leaf economics spectrum), pace‐of‐life (e.g., slow‐to‐fast continuum; lifestyle continuum), evolutionary history (e.g., phylogenetic conservatism), and ecological conditions (e.g., stabilizing selection). Various methods have been used in attempts to partition trait corr
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Ecosystems, Wetland and Aquatic Research Center

Vegetation cover, tidal amplitude and land area predict short-term marsh vulnerability in Coastal Louisiana

The loss of coastal marshes is a topic of great concern, because these habitats provide tangible ecosystem services and are at risk from sea-level rise and human activities. In recent years, significant effort has gone into understanding and modeling the relationships between the biological and physical factors that contribute to marsh stability. Simulation-based process models suggest that marsh
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Ecosystems, Climate Research and Development Program, Land Change Science Program, Wetland and Aquatic Research Center

Development of a multimetric index for integrated assessment of salt marsh ecosystem condition

Tools for assessing and communicating salt marsh condition are essential to guide decisions aimed at maintaining or restoring ecosystem integrity and services. Multimetric indices (MMIs) are increasingly used to provide integrated assessments of ecosystem condition. We employed a theory-based approach that considers the multivariate relationship of metrics with human disturbance to construct a sal
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Ecosystems, Eastern Ecological Science Center, Patuxent Wildlife Research Center

Resource competition model predicts zonation and increasing nutrient use efficiency along a wetland salinity gradient

A trade-off between competitive ability and stress tolerance has been hypothesized and empirically supported to explain the zonation of species across stress gradients for a number of systems. Since stress often reduces plant productivity, one might expect a pattern of decreasing productivity across the zones of the stress gradient. However, this pattern is often not observed in coastal wetlands t
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Ecosystems, Climate Research and Development Program, Land Change Science Program, Wetland and Aquatic Research Center

Causal mechanisms of soil organic matter decomposition: Deconstructing salinity and flooding impacts in coastal wetlands

Coastal wetlands significantly contribute to global carbon storage potential. Sea-level rise and other climate change-induced disturbances threaten coastal wetland sustainability and carbon storage capacity. It is critical that we understand the mechanisms controlling wetland carbon loss so that we can predict and manage these resources in anticipation of climate change. However, our current under
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Ecosystems, Wetland and Aquatic Research Center

Soils mediate the impact of fine woody debris on invasive and native grasses as whole trees are mechanically shredded into firebreaks in piñon-juniper woodlands

To stem wildfires, trees are being mechanically shredded into firebreaks with the resulting fine woody debris (FWD) potentially exerting immense control over soil and plants. We linked FWD-induced changes in microbial activity and nutrient availability to the frequency of Bromus tectorum and three native, perennial grasses across 31 piñon-juniper woodlands, UT, USA. Using a series of mixed models,
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Ecosystems, Sage-grouse & Sagebrush Ecosystem, Wetland and Aquatic Research Center

A landscape-scale assessment of above- and belowground primary production in coastal wetlands: Implications for climate change-induced community shifts

Above- and belowground production in coastal wetlands are important contributors to carbon accumulation and ecosystem sustainability. As sea level rises, we can expect shifts to more salt-tolerant communities, which may alter these ecosystem functions and services. Although the direct influence of salinity on species-level primary production has been documented, we lack an understanding of the lan
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Ecosystems, Wetland and Aquatic Research Center

Barrier displacement on a neutral landscape: Towards a theory of continental biogeography

Macroevolutionary theory posits three processes leading to lineage diversification and the formation of regional biotas: dispersal (species geographic range expansion), speciation (species lineage splitting), and extinction (species lineage termination). The Theory of Island Biogeography (TIB) predicts species richness values using just two of these processes; dispersal and extinction. Yet most sp
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Ecosystems, Wetland and Aquatic Research Center

Do the rich get richer? Varying effects of tree species identity and diversity on the richness of understory taxa

Understory herbs and soil invertebrates play key roles in soil formation and nutrient cycling in forests. Studies suggest that diversity in the canopy and in the understory are positively associated, but these studies often confound the effects of tree species diversity with those of tree species identity and abiotic conditions. We combined extensive field sampling with structural equation modelin
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Ecosystems, Wetland and Aquatic Research Center

Scaling relationships among drivers of aquatic respiration from the smallest to the largest freshwater ecosystems

To address how various environmental parameters control or constrain planktonic respiration (PR), we used geometric scaling relationships and established biological scaling laws to derive quantitative predictions for the relationships among key drivers of PR. We then used empirical measurements of PR and environmental (soluble reactive phosphate [SRP], carbon [DOC], chlorophyll a [Chl-a)], and tem
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Ecosystems, Wetland and Aquatic Research Center
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Louisiana salt marsh

Understanding Impacts of Sea-Level Rise and Land Management on Critical Coastal Marsh Habitat

To ensure successful restoration of coastal wetlands, WARC researchers will measure carbon cycling processes that indicate ecosystem health and sustainability.
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Wetland and Aquatic Research Center
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Understanding Impacts of Sea-Level Rise and Land Management on Critical Coastal Marsh Habitat

To ensure successful restoration of coastal wetlands, WARC researchers will measure carbon cycling processes that indicate ecosystem health and sustainability.
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Salt marsh hydrologic measurement

Development of a Multimetric Index for Integrated Assessment of Salt Marsh Condition in the Northeast Coastal and Barrier Network

Salt marsh ecosystems along all US coastlines have been altered, degraded, and destroyed by human activities, including ditching and drainage of the marsh platform, tidal restrictions, discharge of pollutants, and introduction of invasive species. The National Park Service conducts long-term monitoring of salt marsh vegetation and nekton (fish and free-swimming crustaceans) to provide information...
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Ecosystems, Environments Program, Eastern Ecological Science Center, Patuxent Wildlife Research Center
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Development of a Multimetric Index for Integrated Assessment of Salt Marsh Condition in the Northeast Coastal and Barrier Network

Salt marsh ecosystems along all US coastlines have been altered, degraded, and destroyed by human activities, including ditching and drainage of the marsh platform, tidal restrictions, discharge of pollutants, and introduction of invasive species. The National Park Service conducts long-term monitoring of salt marsh vegetation and nekton (fish and free-swimming crustaceans) to provide information...
Learn More
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2013 Wetland Type Map - Coastal Louisiana

Influence of Sea-Level Rise on Wetland Vegetation Community Structure, Primary Productivity, Organic Matter Decomposition and Carbon Storage

This study will employ a space for time substitution to show long-term effects of rising sea-level and increasing salinity on vegetation community structure, primary production and decomposition. Productivity and decomposition rates will be estimated for four wetland plant community types defined by salinity zones and dominant plant species.
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Ecosystems, Wetland and Aquatic Research Center
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Influence of Sea-Level Rise on Wetland Vegetation Community Structure, Primary Productivity, Organic Matter Decomposition and Carbon Storage

This study will employ a space for time substitution to show long-term effects of rising sea-level and increasing salinity on vegetation community structure, primary production and decomposition. Productivity and decomposition rates will be estimated for four wetland plant community types defined by salinity zones and dominant plant species.
Learn More
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USGS: Louisiana’s Rate of Coastal Wetland Loss Continues to Slow

Lack of Major Hurricanes Since 2008 Is Likely the Main Reason

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Land area change in coastal Louisiana (1932 to 2016)

Coastal Louisiana wetlands are one of the most critically threatened environments in the United States. These wetlands are in peril because Louisiana currently experiences greater coastal wetland loss than all other States in the contiguous United States combined. The analyses of landscape change presented here have utilized historical surveys, aerial, and satellite data to quantify landscape chan
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Ecosystems, Wetland and Aquatic Research Center

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