Soil water availability in desert ecosystems is often highly variable in space and time due to the scarcity and variability of precipitation. The spatial and temporal variations of soil water are a key determining factor for plant distribution and community structure in desert ecosystem.
How do the desert plants adapt to seasonal variations in soil water and the periodic and chronic water scarcity in desert ecosystem, especially, under the future climate change scenarios with predicted increase in the frequency and intensity of drought and changes in regional precipitation patterns?
Scientists from Xinjiang Institute of Ecology and Geography (XIEG) studied the water sources of six desert shrubs co-occurring in the Gurbantonggut Desert to examine contrasting water use patterns adopted by the co-existing desert shrubs.
The Gurbantonggut Desert ecosystem, being second largest desert in China, is the most important desert ecosystem, and C3 and C4 shrubs are the dominant species in this desert ecosystem. C3 and C4 plants adopt far distinct photosynthetic path ways due to the differential leaf structure with C4 having chlorophylls in the bundle sheath cells. Theses structural differences contributed the contrasting carbon assimilation and water use efficiencies of the two types of plants.
The results of the study showed that desert plants use different water sources in space and time, as well as adopt their root functioning to adjust to the temporal and spatial variations in soil water availability, which is one of the key strategies for the desert shrubs to deal with periodic water scarcity.
“The differential water uptake between shrubs with distinct rooting depth was an important mechanism,” said Ma jianying, the leading scientist of the study from XIEG, “which enable desert shrubs to partition ecological niche and co-exist in water limited ecosystem.”
In the meantime, distinct shoot eco-physiological performance occurred between shrubs with similar seasonal water uptake pattern under same soil water condition, which might be beneficial to shrubs to lessen the competition to the limited water sources, according to Ma. The study, published in Science of the Total Environment