277 Critical Zone Science: Intersection of Processes Linked to Geomorphology, Ecology, Fire and Climate

This session welcomes interdisciplinary studies that investigate the rates and processes of soil development, regolith formation, carbon storage and the role of ecological and/or hydrologic feedbacks in shaping the landscape (both past and present).

Wednesday, 22 October 2025
1:30 PM - 5:30 PM
HBGCC, 212AB

Understanding Trace Elements as Stressors of Plant Physiological Responses in Agroforests Under the Modulation of Critical Zone Architecture

Paper number: 277-3
Program: Technical Sessions
Time: 2:10 PM – 2:25 PM

Authors

Abstract

Pecan trees (Carya illinoinensis) in the southwestern U.S. face increasing stress from drought and heat, salinity, and trace element accumulation, driven by groundwater depletion and irrigation practices. These stressors impair photosynthesis, stomatal regulation, and nutrient uptake, threatening productivity during nut filling. This study examines how soil texture influences trace elements (As, B, Cu, Fe, Mn, Ni, Zn) accumulation and leaf-level physiological responses in a pecan orchard in Tornillo, Texas. Sampling was informed by prior findings at the orchard showing that soil texture influences hydrology and elemental retention. Six trees were selected, three in fine-textured soil (silts and clays) and three in coarse-textured soil (sands). From June to November, leaf samples were collected every three weeks post-irrigation from upper and lower canopy positions. We analyzed leaf content of trace elements, nutrients, and pigments, and measured photosynthetic efficiency and stomatal conductance. Soil and irrigation water were sampled to characterize trace element concentrations and soil properties. Preliminary results show that soil texture mediates nutrient and trace element uptake: trees in coarse soils had higher concentrations of essential nutrients (N, P, K), while those in fine soils showed greater accumulation of harmful elements (As, Ni), altering physiological performance. Limited water infiltration in finer soil appears to promote salt and trace element retention in the root zone, intensifying physiological stress. In contrast, coarse soils facilitated greater leaching and reduced accumulation of trace elements. These findings suggest that soil texture driven changes in hydrological dynamics to shape the environmental exposure of pecan trees, ultimately affecting leaf function and yield potential. Understanding these interactions is critical for developing soil-specific strategies to sustain pecan production under increasing environmental stressors.

Geological Society of America Abstracts with Programs. Vol. 57, No. 6

doi: 10.1130/abs/2025AM-413084

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