Water use patterns of Caragana korshinskii and Tamarix ramosissima in
different ages in western Chinese Loess Plateau
Abstract
Caragana korshinskii and Tamarix ramosissima are pioneer
shrubs for water and soil conservation and windbreak and sand fixation
in arid and semi-arid areas. Understanding the water use patterns of
C. korshinskii and T. ramosissima and their response to
rainfall is of great importance for their survival in regions where
drought occurs. In this work we present the monitoring results of stable
isotopes in soil water (depths from 0 to 200 cm), twig xylem water of
juvenile, intermediate, and adult C. korshinskii and T.
ramosissima. The monitoring campaign took place in western Chinese
Loess Plateau from July to October 2020. During the same period, we also
measured relevant environmental and meteorological variables and soil
water content. The results showed that juvenile and of intermediate age
C. korshinskii both mainly absorb water from the surface (0–10
cm) and shallow (10–40 cm) soil layers, but adult C. korshinskii
use mainly water from the deep soil layers. Juvenile and of intermediate
age T. ramosissima extract water from deep soil layers, while
adult T. ramosissima use mainly water from middle (40–100 cm)
soil depths. Both plant species increase the proportion of surface and
shallow soil layer water after precipitation. This increase is more
pronounced and faster for the C. korshinskii of intermediate age
rather than for juvenile and adult plants. On the contrary, it is the
absorption of surface and shallow soil water from juvenile and of
intermediate T. ramosissima plants that fluctuates more after
precipitation than from adult plants. Our findings provide a reference
for vegetation restoration and ecological management of the western
Chinese Loess Plateau.