Water use by broadleaved tree species in response to changes in precipitation in a mountainous area of Beijing

• Published in: Agriculture, ecosystems & environment ecosystems & environment, 2018-01, Vol.251, p.132-140
• Main Authors: Liu, Ziqiang, Jia, Guodong, Yu, Xinxiao, Lu, Weiwei, Zhang, Jieming
• Format: Article
• Language: English
• Subjects: Adaptability; Drought; Environmental conditions; Extreme weather; Groundwater; Groundwater treatment; Hygroscopic water; Iso-Source mixing model; Moisture content; Mountainous areas; Mountains; Precipitation; Quercus variabilis; Soil conditions; Soil layers; Soil treatment; Soil water; Stable isotopes; Studies; Transpiration; Trees; Water content; Water depth; Water distribution; Water engineering; Water treatment; Water uptake; Water use; Water use patterns
• ISSN: 0167-8809; 1873-2305
• DOI: 10.1016/j.agee.2017.09.021

•Water absorption by a typical broadleaved tree were studied in Northern China.•Stable isotope approach was adopted to quantify different water sources.•The tree showed plasticity in depths of water uptake under a precipitation gradient.•Selection of trees with varied water sources is vital in maintaining forest stability. Extreme weather events are expected to occur more frequently in the future, which may influence water distribution and uptake patterns in rocky mountainous areas of North China. To examine how plants respond and adapt to the extreme environment, we investigated water sources of the broadleaved tree species Quercus variabilis under a precipitation gradient (A: no natural precipitation, B: half of natural precipitation, C: natural precipitation, and D: twice the natural precipitation) using the stable isotope approach in the Beijing mountainous area. The results indicated that Q. variabilis exhibited considerable plasticity in the depth of water uptake and showed a strong dependence on deeper soil layers under the precipitation gradient. Q. variabilis mainly absorbed water from the 0–20cm (20.02–28.61%) and 60–80cm (22.81–29.44%) soil layers, and also used groundwater (26.32–30.54%) under the low soil water conditions of the A treatment. In the B treatment, Q. variabilis absorbed water from the groundwater (29.60–33.53%) and 60–80cm (26.05–29.44%) soil layers and a small amount of water from 0 to 20cm (10.67–12.25%). In the C and D treatments, the soil water content was greater than that of the B treatment; Q. variabilis still predominantly absorbed water from the 60–80cm (26.88% and 27.35%, respectively) soil layer and groundwater (33.52% and 46.17%, respectively), and took minimal water from the 0–20cm and 20–40cm soil layers. We found that Q. variabilis showed no obvious responses to precipitation under the precipitation gradient, and its dimorphic root system allowed it to uptake different water sources under drought and humid environmental conditions and thus maintain its transpiration. Therefore, we can infer that Q. variabilis is well adapted to extreme precipitation events and has a strong adaptability to both extreme drought and flood conditions.