Cheatgrass (Bromus tectorum) is a widespread species of concern throughout the western US, as it dominates many low‐elevation rangelands and continues to spread annually. As a winter annual grass, however, cheatgrass can produce high‐quality and cheap protein forage for livestock early in the growing season. Estimating biomass can lead to better management in these western United States and Great Basin plant communities. The present study was designed to evaluate the accuracy of biomass simulations in Great Basin plant communities using the process‐based Agricultural Land Management Alternative with Numerical Assessment Criteria (ALMANAC) model as it simulates biomass production and competing species interactions. For this study, data were used from the Sagebrush Steppe Treatment Evaluation Project to simulate cheatgrass, perennial grass, forb, and sagebrush biomass across three community types: native, invaded, and a co‐dominated community of sagebrush, perennial grasses, cheatgrass, and forbs at six representative Great Basin sites from 2006 to 2018. Our results indicated a strong relationship between simulated and measured biomass of total cheatgrass and perennial grasses across the three plant communities. Sagebrush and forb biomass were poorly simulated across most plant community types. Model accuracy also varied by site, largely depending on elevation. We saw high variability in simulated biomass across years, likely because of the single point‐in‐time measurements at peak biomass and the low biomass values of cheatgrass and forbs. Collectively, ALMANAC shows potential for assessing biomass production and plant interactions but will require more data and model development to fully comprehend its utility.

中文翻译：

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使用 ALMANAC 模拟大盆地的鼠尾草-鼠尾草植物群落生物量生产


禾本科植物 （Bromus tectorum） 是美国西部广泛关注的物种，因为它在许多低海拔牧场占据主导地位，并且每年都在继续蔓延。然而，作为一种冬季一年生草，鼠尾草可以在生长季节的早期为牲畜生产优质且廉价的蛋白质草料。估算生物量可以更好地管理这些美国西部和大盆地植物群落。本研究旨在使用基于过程的农业土地管理替代方案与数值评估标准 （ALMANAC） 模型评估大盆地植物群落生物量模拟的准确性，因为它模拟了生物量生产和竞争物种的相互作用。在这项研究中，使用了来自 Sagebrush 草原处理评估项目的数据来模拟三种群落类型的鼠尾草、多年生草、杂草和鼠尾草生物量：本地、入侵和共同主导的鼠尾草、多年生草、鼠尾草和杂草群落，从 2006 年到 2018 年在六个具有代表性的大盆地地点。我们的结果表明，三个植物群落中总禾本科植物和多年生禾本科植物的模拟和测量生物量之间存在很强的关系。鼠尾草和杂草生物量在大多数植物群落类型中的模拟效果不佳。模型的准确性也因地点而异，主要取决于海拔高度。我们发现多年来模拟生物量的变化很大，这可能是因为峰值生物量的单点测量以及 cheatgrass 和 forbs 的生物量值较低。总的来说，ALMANAC 年鉴显示出评估生物质生产和植物相互作用的潜力，但需要更多的数据和模型开发才能充分理解其效用。