Tortoises inhabit arid regions where they may represent a significant herbivorous component, but are among the most threatened of tetrapod groups. Studying tortoise diets can help predict potential trophic disruptions following extinctions of tortoise populations, and inform conservation. We studied the diet of Karoo dwarf tortoises (Chersobius boulengeri), an endangered endemic of the arid Nama and Succulent Karoo biomes in South Africa, using vegetation analysis, DNA metabarcoding, morphological evaluation of faeces, a germination trial, and focal feeding observations. DNA metabarcoding was highly successful in the identification of dietary items. Karoo dwarf tortoises fed on a broad diet, including approximately 10 taxa eaten frequently. Specifically, doll's roses (five species in the genus Hermannia) were eaten more frequently than would be expected based on their availability, whereas grasses were rejected, for a dietary Proportional Similarity Index of 0.31–0.38. Dietary selection was likely related to water and nutrient contents of plant taxa. At least four plant species (including doll's roses) germinated from faecal samples, suggesting mutualistic relationships with Karoo dwarf tortoises. The habitat preference of Karoo dwarf tortoises (i.e., well-structured rocky terrain) may provide germination microsites with ample shade and run-off water to benefit seedling recruitment in an arid environment.

陆龟生活在干旱地区，在那里它们可能是重要的草食动物，但也是最受威胁的四足动物群体之一。研究陆龟的饮食可以帮助预测陆龟种群灭绝后潜在的营养破坏，并为保护提供信息。我们利用植被分析、DNA 元条形码、粪便形态学评估、发芽试验和集中摄食观察，研究了卡鲁矮龟（Chersobius boulengeri）的饮食，卡鲁矮龟是南非干旱纳马和肉质卡鲁生物群落的濒危特有种。DNA 元条形码在识别饮食项目方面非常成功。卡鲁矮龟的饮食广泛，包括大约 10 种经常食用的类群。具体来说，娃娃玫瑰（赫曼尼亚属的五个物种）的食用频率比根据其可用性所预期的要高，而草则被拒绝，膳食比例相似性指数为 0.31-0.38。饮食选择可能与植物类群的水分和营养成分有关。至少有四种植物（包括洋娃娃玫瑰）从粪便样本中发芽，表明它们与卡鲁矮龟存在互惠关系。卡鲁矮龟的栖息地偏好（即结构良好的岩石地形）可以为发芽微场所提供充足的遮荫和径流水，以利于在干旱环境中幼苗的补充。