Scientists and natural resource managers require suitable vegetation survey methods to assess the success of rangeland restoration projects. Visual estimation and point intercept methods are commonly used to evaluate vegetation cover. This study compared the performance of one visual (quadrat-based) and two line-point intercept (LPI, canopy and basal) methods to assess biodiversity and cover and to estimate biomass production on sites invaded by introduced annual grasses across Wyoming, USA. Greater species richness and higher Shannon index values were measured in quadrats, while introduced annual and native perennial graminoid cover values were higher in LPI canopy in general. Overall, these outcomes indicate quadrats as the most suitable survey method when biodiversity monitoring is the primary objective, while suggesting LPI canopy when monitoring vegetation cover is prioritized. Finally, our regression models indicated quadrat-based estimates as the most reliable to predict introduced annual and native perennial graminoid biomass.

中文翻译：

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怀俄明州一年生草侵草地的目测估计和线点截距植被调查方法比较

科学家和自然资源管理者需要合适的植被调查方法来评估牧场恢复项目的成功与否。视觉估计和点截距方法通常用于评估植被覆盖度。本研究比较了一种视觉（基于样方）和两种线点截距（LPI、冠层和基础）方法的性能，以评估生物多样性和覆盖率，并估计在美国怀俄明州被引入的一年生草入侵的地点的生物量产量。在样方中测量到更大的物种丰富度和更高的香农指数值，而在 LPI 冠层中引入的年度和原生多年生禾本科植物覆盖值总体上更高。总体而言，这些结果表明，当生物多样性监测是主要目标时，样方是最合适的调查方法，同时在优先监测植被覆盖时建议 LPI 冠层。最后，我们的回归模型表明，基于样方的估计是预测引入的年度和原生多年生禾本科生物量的最可靠的方法。