Desert wetlands record hydrologic variability within the Younger Dryas chronozone, Mojave Desert, USA

Abstract

One of the enduring questions in the field of paleohydrology is how quickly desert wetland ecosystems responded to past episodes of abrupt climate change. Recent investigations in the Las Vegas Valley of southern Nevada have revealed that wetlands expanded and contracted on millennial and sub-millennial timescales in response to changes in climate during the late Quaternary. Here, we evaluate geologic evidence from multiple localities in the Mojave Desert and southern Great Basin that suggests the response of wetland systems to climate change is even faster, occurring at centennial, and possibly decadal, timescales. Paleowetland deposits at Dove Springs Wash, Mesquite Springs, and Little Dixie Wash, California, contain evidence of multiple wet and dry cycles in the form of organic-rich black mats, representing periods of past groundwater discharge and wet conditions, interbedded with colluvial, alluvial, and aeolian sediments, each representing dry conditions. Many of these wet-dry cycles date to within the Younger Dryas (YD) chronozone (12.9–11.7 ka), marking the first timeintra-YD hydrologic variability has been documented in paleowetland deposits. Our results illustrate that desert wetland ecosystems are exceptionally sensitive to climate change and respond to climatic perturbations on timescales that are relevant to human society.

Where did the water come from? Wetlands and shallow lakes in semi‐arid dunefields from South America during the Pleistocene–Holocene transition

“…13 and 12.5 ka bp in Luján (34°35′S, 59°10′W) (Toledo, 2011). Globally, paleowetland deposits during the Younger Dryas were recognized in other drylands that received monsoonal precipitations, such as localities of southwestern North America (Pigati et al ., 2019 and references therein) while the regional expression of moisture conditions is controversial in East Asia (e.g. Wu et al ., 2022; Liu et al ., 2023).…”

Features of Plant Community and Driving Forces of Plant Community Succession in the Typical Desert Wetlands

“…The structure and function of wetlands are changed by the strong interactions between hydrological and ecological processes [24]. The process of wetland ecological hydrology is currently one of the most important research contents of ecological hydrology [25]. In the restoration design of the Tarim River wetland, the species and number of plants have increased significantly through the ecological management of the upper and middle reaches, and then the vegetation coverage has also significantly increased [26].…”