Typical plant water use strategies in the eastern part of the Loess Plateau under the background of ecological restoration
Water is an important limiting factor for plant growth in arid and semi-arid areas,and studying the water-use strategies of different types of plants under different water conditions has become a key to ecological protection and vegetation restoration in the Chinese Loess Plateau region.Through the systematic collection and analysis of stable isotopes of typical ecological restoration plants,food crops and water sources with potential water sources of regional plants in the eastern part of the Loess Plateau,this study used the Bayesian mixing model MixSIAR to quantitatively study the water-use strategies of typical plants under four geomorphic types(river valley plain region(RVP),rocky mountain region(EMR),loess hilly region(LH)and loess gully region(LG).The results show that:(1)Significant spatial and temporal heterogeneity was observed in regional soil water content and soil water stable isotopes,with larger fluctuations in soil water isotope values appearing in the EMR region,the relatively stable soil water content and the smallest vertical difference of stable isotopic value of hydrogen and oxygen in soil water observed in the LH landscape.(2)The xylem water stable isotopes of Robinia pseudoacacia and Juniperus chinensis displayed obvious seasonal fluctuations,both tree species fluctuated greatly in April and less in December,whereas Malus pumila and Pyrus spp.had weak seasonal variability.The water isotopes of Artemisia lavandulifolia was enriched in the LH in April and December,and enriched in the gully in June and September.For crops,the range of the water isotopes for T.aestivum was larger than that of Z.mays.(3)In spring and summer,R.Pseudoacacia and J.chinensis mainly use 0-20 cm soil layer in the ERM region,and mainly use precipitation in the LH and LG region,whereas deep layers soil water becomes the main source in the four landform types during the winter.(4)A.Lavandulifolia mainly uses surface soil water,and the proportion of deep soil water utilization increases after September,representing strong ecological plasticity in its water-use strategy.Surface soil water was the main water source for T.aestivum during the overwintering and reviving periods,and Z.mays utilized the largest proportion of surface soil water during the seeding and maturation stages.In summary,the results of this study have important implications for sustainable vegetation protection and the optimal allocation of water resources in the study area.
stable isotopestypical plantsplant water useChinese Loess Plateau
万方数据
维普
