TY - JOUR
T1 - A First Study of Urginea maritima Rings
T2 - A Case Study from Southern Jordan
AU - Yizhaq, Hezi
AU - Al-Tawaha, Abdel Rahman Mohammad Said
AU - Stavi, Ilan
N1 - Funding Information:
Acknowledgments: We thank Ehud Meron for the fruitful discussions, which substantially improved the manuscript. The Dead Sea and Arava Science Center is supported by the Israel Ministry of Science and Technology. Also, the authors thank two anonymous reviewers, whose comments allowed the substantial improvement of the manuscript’s original version.
Publisher Copyright:
© 2022 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2022/2/1
Y1 - 2022/2/1
N2 - Vegetation rings are a common pattern in water-limited environments and mostly occur in clonal plants. This study presents, for the first time, rings of the geophyte species Urginea maritima. The rings, typically 40–90 cm in diameter, are abundant in the sandy environment of Little Petra and Wadi Rum, in the southern Jordanian drylands. Soil properties were studied in the rings’ center, periphery, and matrix. Soil-water volumetric content was significantly higher in the rings’ periphery than in the center and matrix. The soil organic carbon was highest in the periphery, intermediate in the center, and lowest in the matrix. At the same time, the soil texture, hydraulic conductivity, and gravimetric moisture content at the hygroscopic level were similar in the three microenvironments. According to the results, a possible ring formation mechanism is the soil-water uptake mechanism, which results in competition between the plants at the periphery and those in the center and is generally attributed to plants with large lateral root zones. Numerical simulations of a mathematical model implemented in this study support the soil-water uptake mechanism. A second possible mechanism is negative plant-soil feedback due to the accumulation of dead biomass and its consequent decomposition, with the resultant release of autotoxic compounds. It is possible that several mechanisms occur simultaneously and synergistically affect the formation of U. maritima rings.
AB - Vegetation rings are a common pattern in water-limited environments and mostly occur in clonal plants. This study presents, for the first time, rings of the geophyte species Urginea maritima. The rings, typically 40–90 cm in diameter, are abundant in the sandy environment of Little Petra and Wadi Rum, in the southern Jordanian drylands. Soil properties were studied in the rings’ center, periphery, and matrix. Soil-water volumetric content was significantly higher in the rings’ periphery than in the center and matrix. The soil organic carbon was highest in the periphery, intermediate in the center, and lowest in the matrix. At the same time, the soil texture, hydraulic conductivity, and gravimetric moisture content at the hygroscopic level were similar in the three microenvironments. According to the results, a possible ring formation mechanism is the soil-water uptake mechanism, which results in competition between the plants at the periphery and those in the center and is generally attributed to plants with large lateral root zones. Numerical simulations of a mathematical model implemented in this study support the soil-water uptake mechanism. A second possible mechanism is negative plant-soil feedback due to the accumulation of dead biomass and its consequent decomposition, with the resultant release of autotoxic compounds. It is possible that several mechanisms occur simultaneously and synergistically affect the formation of U. maritima rings.
KW - Central dieback
KW - Geophyte
KW - Plant-soil feedback
KW - Soil-water content
KW - Vegetation ring
KW - Water uptake mechanism
UR - http://www.scopus.com/inward/record.url?scp=85124838686&partnerID=8YFLogxK
U2 - 10.3390/land11020285
DO - 10.3390/land11020285
M3 - Article
AN - SCOPUS:85124838686
VL - 11
JO - Land
JF - Land
SN - 2073-445X
IS - 2
M1 - 285
ER -