Schwinning Lab

Plant Ecology

Yang Tse

Karst Ecohydrology

Tree in rock
A road cut exposes how roots grow through the rock
Roots in rock
Flattened roots of juniper wedged between two rock slabs

Texas State University is located on the edge of the Edwards Plateau, a limestone karst. Karst regions are characterized by thin, rocky soils and outcrops. Over millennia, flowing water erodes the rock below and creates gaps and cavities that enhance water storage capacity, but also allow storm waters to rapidly flow through to deep aquifers.

Not much is known about the rooting habits of woody plants in karst. A high degree of endemism in karst areas suggest that plants require special adaptations for living in karst. Trees typically take up both soil- and rock-stored water, but in what proportions is not well known and may vary greatly among species and across space and time.

In collaboration with Dr. Jennifer Jensen and Dr. Benjamin Schwartz of Texas State University, San Marcos as well as Dr. James Heilman of Texas A&M University, among others,our lab investigates how the rocky substrate of karst regions affects the responses of woody vegetation to precipitation in general and drought in particular.


Tokumoto, I., Heilman, J.L, Schwinning, S., McInnes, K.J., Litvak, M.E., Morgan, C.L., Kamps, R.H. 2014. Small-scale variability in water storage and plant available water in shallow, rocky soils. Plant and Soil,385:193-204 pdf

Schwartz, B.F., Schwinning, S., Gerard, B.M., Kukowski, K.R., Stinson, C.L., Dammeyer, H.C. 2013. Using hydrochemical and ecohydrologic responses to understand epikarst process in semi-arid systems, Edwards Plateau, Texas, USA. Acta Carsiologica 42: 316-325. pdf

Kukowski, K., Schwinning, S., Schwartz, B. 2013. Hydraulic responses to extreme drought conditions in three co-dominant tree species in shallow soil over bedrock, Oecologia 171:819-830. pdf




Lab News

Recent student presentations

Nathan Custer presented on his research at the Ecological Society of America Meeting in Portland. The title of his presentation was "Effect of transplant size on early survivorship". The paper was presented in a session on "Multiple Common Garden Experiments for Meeting Restoration Challenges: Difficulties and Potential Pitfalls" organized by Susanne Schwinning and Lesley DeFalco.

Highlighted publications

Schwinning, S., Meckel, H., Reichmann, L.G., Polley, H.W., Fay, P.A. 2017. Accelerated development in Johnsongrass seedlings (Sorghum halepense) suppresses the growth of native grasses through size-asymmetric competition. PLOS ONE 12, 20176042 pdf

Dammeyer, H.C., Schwinning, S., Schwartz, B., Moore, G. 2016. Effects of juniper removal and rainfall variation on tree transpiration in a semi-arid karst: Evidence of complex water storage dynamics. Hydrological Processes 30: 4568-4581. pdf

Other lab news

The lab welcomes two new graduate students:

Kayla Sustaita will examine the effects of adaptive rotational grazing on soil characteristics.

Logan Maxwell will investigate best restoration practices for abandoned oil and gas exploration fields in Utah.

The lab was awarded two federal grants in 2015:

NSF proposal : DEB-1557176: "Collaborative Research: Hydrological tipping points and desertification of semi-arid woodlands".

The DOD Legacy Award HQ0034-16-2-0006: "Characterizing Mojave Desert shrub ecotypes to establish seed transfer zones for military range restoration".

In the media

In August 2016, Susan was interviewed by Salwa Khan for the Wimberley Valley Radio show "Mothering Earth" Listen to the podcast here.

In September 2013, Susan was interviewed by Alan Knapp on a paper published in Functional Ecology. Listen to the podcast here.

Contact information
Susan Schwinning
601 University Drive
312 Supple Science Bldg
Texas State University
San Marcos, TX 78666, USA
Phone: (512) 245-3753
Fax: (512) 245-8713

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Biology Department
Texas State University

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Comments on the contents of this site should be directed to Susan Schwinning