Donald Schoolmaster, Ph.D.
Biography
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
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...
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.
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...
Cronin, James P.; Schoolmaster, Donald 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...
Nagel, Jessica L.; Neckles, Hilary A.; Guntenspergen, Glenn R.; Rocks, Erika N.; Schoolmaster, Donald; Grace, James B.; Skidds, Dennis E.; Stevens, Sara 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....
Schoolmaster, Donald; Stagg, Camille L.; Sharp, Leigh Anne; McGinnis, Tommy S.; Wood, Bernard; Piazza, Sarai 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...
Schoolmaster, Donald; Stagg, Camille L. Primary production across a coastal wetland landscape in Louisiana, U.S.A. (2012-2014)
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...
Stagg, Camille L.; Schoolmaster, Donald; Piazza, Sarai; Snedden, Gregg; Steyer, Gregory D.; Fischenich, Craig J; McComas, Robert W.
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,...
Couvillion, Brady R.; Beck, Holly; Schoolmaster, Donald; Fischer, Michelle 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...
Stagg, Camille L.; Schoolmaster, Donald; Krauss, Ken W.; Cormier, Nicole; Conner, William H. 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...
Aanderud, Zachary T.; Schoolmaster, Donald R.; Rigby, Deborah; Bybee, Jordon; Campbell, Tayte; Roundy, Bruce A. 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...
Stagg, Camille L.; Schoolmaster, Donald R.; Piazza, Sarai C.; Snedden, Gregg; Steyer, Gregory D.; Fischenich, Craig J; McComas, Robert W. 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...
Albert, James S.; Schoolmaster, Donald; Tagliacollo, Victor; Duke-Sylvester, Scott M. 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...
Champagne, Juilette; Paine, C. E. Timothy; Schoolmaster, Donald; Stejskal, Robert; Volařík, Daniel; Šebesta, Jan; Trnka, Filip; Koutecký, Tomáš; Švarc, Petr; Svátek, Martin; Hector, Andy; Matula, Radim 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 [...
Hall, Ed K; Schoolmaster, Donald; Amado, A.M; Stets, Edward G.; Lennon, J.T.; Domaine, L.; Cotner, J.B.
USGS: Louisiana’s Rate of Coastal Wetland Loss Continues to Slow
Lack of Major Hurricanes Since 2008 Is Likely the Main Reason