Tamaulipan Saline Thornscrub

Geology

Frequently associated with the Yegua Formation or the Jackson Group.

Landform

Gently rolling to low flats, sometimes dissected by minor drainages.

Soils

Most saline sites within the Saline Clay and Saline Clay Loam Ecological Site.

Parent Description

This system is an open shrubland on sites where soil salinity is particularly high on saline clays such as Montell saline clays, Maverick, and Catarina soils. Soils mapped as saline clay or saline clay loam, but where soil salinity is not extreme, will be occupied by Tamaulipan Mixed Deciduous Shrubland. Often, Tamaulipan Calcareous Shrubland occurs upslope of this system. This system is often on level flats to gently rolling landscapes, and soils may have a veneer of gravel over the clay. Prosopis glandulosa (honey mesquite) usually forms a scattered emergent canopy less than 5 m in height, creating an overstory canopy cover of around 10%. Shrubs and subshrubs, such as Varilla texana (saladillo), Castela erecta (amargosa), Acacia rigidula (blackbrush), Atriplex canescens (four-wing saltbush), Isocoma coronopifolia (goldenweed), Condalia spathulata (knifeleaf condalia), Jatropha dioica (leatherstem), Suaeda spp. (seepweeds), Opuntia engelmannii var. lindheimeri (Lindheimer prickly pear), Cylindropuntia leptocaulis (tasajillo), Xylothamia palmeri (South Texas ericameria), Tiquilia canescens (oreja de perro), and Prosopis reptans (tornillo), are conspicuous elements of the relatively open shrubland (20 to 70% canopy cover). Patchy grasses typify the herbaceous layer, with such species as Hilaria belangeri (curly mesquite), Sporobolus pyramidatus (whorled dropseed), Pappophorum bicolor (pink pappusgrass), Bouteloua dactyloides (buffalograss), Bouteloua trifida (red grama), and occasionally Monanthochloe littoralis (shoregrass). Forbs such as Billieturnera helleri (Billieweed), Chamaesyce albomarginata (white-lip matspurge), Heliotropium curassavicum (seaside heliotrope), and Thymophylla pentachaeta (parralena), may be present and conspicuous. Cacti are sometimes well-represented in the ground layer, including species such as Echinocereus reichenbachii var. fitchii (Fitch's hedgehog cactus), Escobaria emskoetteriana (Robert's foxtail-cactus), Mammillaria heyderi (Heyder's nipple-cactus), Sclerocactus scheeri (fishhook cactus), Echinocactus texensis (horse crippler), and Thelocactus setispinus (twisted rib cactus).