Liu Bao Qing, Liu Zhi Min, Qian Jian Qiang, Zhang Feng Li, Peng Xin Hua
Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.
University of Chinese Academy of Sciences, Beijing 100049, China3Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
Ying Yong Sheng Tai Xue Bao. 2017 Jul 18;28(7):2093-2101. doi: 10.13287/j.1001-9332.201707.030.
It's important to explore the water sources of sand-binding plants and their relationship to reveal the mechanism underling species coexistence and vegetation stability. In the present study, 12 sand-binding species in two typical habitats (fixed dune and dune slack) in southern Horqin Sandy Land were selected. The δD and δO values of plant water, rain water, ground water and soil water were determined, and the percentages of soil water at different depths used by plants were calculated with the IsoSource model. Our results showed that the δD and δO values of stem water were significantly different among various life forms in both habitats except for those of trees and shrubs in dune slack. From trees to grass, the depth of soil water contributed to main water source of plant became shallower in dune slack: trees and shrubs mainly used soil water in 50-150 cm or 30-50 cm layer, subshrubs mainly used soil water in 10-30 cm layer while grass relied on soil water of 0-10 cm layer. Shrubs mainly used soil water of 0-30 cm layer and subshrubs mainly used soil water around 50 cm at fixed dune. This study indicated that in dry season plants at fixed dune are more dependent on soil water of 0-50 cm layer compared with those in dune slack. The water sources of sand-binding plants are correlated with plant life form and root distribution range, and the later might play a more important role.
探究固沙植物的水源及其关系对于揭示物种共存和植被稳定性的潜在机制至关重要。在本研究中，选取了科尔沁沙地南部两个典型生境（固定沙丘和丘间低地）中的12种固沙植物。测定了植物水、雨水、地下水和土壤水的δD和δO值，并使用IsoSource模型计算了植物利用的不同深度土壤水的百分比。我们的结果表明，除丘间低地的乔木和灌木外，两个生境中不同生活型植物茎水的δD和δO值均存在显著差异。在丘间低地，从乔木到草本，植物主要水源的土壤水深度逐渐变浅：乔木和灌木主要利用50 - 150 cm或30 - 50 cm土层的土壤水，半灌木主要利用10 - 30 cm土层的土壤水，而草本则依赖0 - 10 cm土层的土壤水。在固定沙丘，灌木主要利用0 - 30 cm土层的土壤水，半灌木主要利用50 cm左右的土壤水。本研究表明，在干旱季节，与丘间低地的植物相比，固定沙丘的植物对0 - 50 cm土层土壤水的依赖性更强。固沙植物的水源与植物生活型和根系分布范围相关，且后者可能发挥更重要的作用。
