An improved understanding of the relationships among vegetation, groundwater level, and microtopography is crucial for making well-informed management decisions in areas with shallow groundwater resources. We measured plant species abundance/composition and richness in relation to depth to groundwater (DTW) and microtopography in Owens Valley, California, particularly in areas where DTW ranged from 0 to 4 m. Sampling occurred along 67 vegetation transects across three community types. Relationships between DTW and community composition were evaluated using non-metric multidimensional scaling (NMS), while non-parametric multiplicative regression was used to relate DTW and microtopography to species abundance. The dominant gradient in species composition (NMS Axis 1) explained ~51% of variation in our distance matrix and was most strongly associated (r = 0.55) with DTW. The graminoids Juncus arcticus, Leymus triticoides, and Distichlis spicata had strong affinities toward areas with the shallowest DTW (<1.5 m). One salt-adapted species Sporobolus airoides and one shrub Ericameria nauseosa dominated areas with intermediate DTW (1.5–2.0 m), whereas the shrubs Atriplex torreyi, Sarcobatus vermiculatus, and Artemisia tridentata were dominant in areas with deeper DTW (>2.0 m). Variation in microtopography affected species abundance and increased species richness for vegetation communities at either extreme of the water table gradient, shallow, and deep DTW but not the intermediate DTW. Findings indicate that desert plant communities from shallow aquifers have adapted to different DTW and microtopography conditions and that considering those adaptations may be important to manage groundwater and vegetation resources in these areas.

更好地了解植被、地下水位和微地形之间的关系对于在地下水资源较浅的地区做出明智的管理决策至关重要。我们测量了加利福尼亚州欧文斯谷与地下水深度 (DTW) 和微地形相关的植物物种丰度/组成和丰富度，特别是在 DTW 范围为 0 到 4 m 的地区。采样发生在三种群落类型的 67 个植被样带上。使用非度量多维尺度 (NMS) 评估 DTW 与群落组成之间的关系，而非参数乘法回归用于将 DTW 和微地形与物种丰度联系起来。r  = 0.55) 与 DTW。禾本科植物Juncus arcticus、Leymus triticoides和Distichlis spicata对 DTW 最浅 (<1.5 m) 的区域具有很强的亲和力。一种盐适应种Sporobolus airoides和一种灌木Ericameria nauseosa以中等 DTW (1.5-2.0 m) 为主，而灌木Atriplex torreyi、 Sarcobatus vermiculatus和Artemisia tridentata在DTW较深（> 2.0 m）的地区占主导地位。微地形的变化影响了物种丰度并增加了地下水位梯度、浅部和深部 DTW 任一极端的植被群落的物种丰富度，但不影响中间 DTW。研究结果表明，来自浅层含水层的沙漠植物群落已经适应了不同的 DTW 和微地形条件，考虑到这些适应对于管理这些地区的地下水和植被资源可能很重要。