Herbicide programs change weed population density as well as weed community composition. The repeated use of a given program can result in a weed community that progressively becomes more difficult to manage or could lose its ability to provide ecosystem services. Simulation of those changes using stochastic models considering population dynamics of multiple species makes it possible to identify a priori potential community changes that might result from the use of a given herbicide program. The objectives of this work were to model the population dynamics of weed species under different herbicide programs and how those dynamics change weed community diversity over time. Weed population dynamics were stochastically modeled along ten years using population growth rate (lambda) for each species under different herbicide programs. Lambda values were obtained from an eight-year long, field experiment, and these were used to parameterize the stochastic ranges for the model for each weed species. Population trajectories were modeled for each individual species over ten years and the results were used to estimate richness, diversity, and evenness for each herbicide use scenario. The repeated use of glyphosate alone had a minimal effect on richness, but it caused a strong reduction in weed diversity and evenness. Programs with more mechanisms of action and the use of both preemergence and postemergence herbicides were slightly more likely to suffer the loss of weed species than programs with single or just a few herbicides. Conversely, the former had a higher probability of maintaining weed diversity and evenness than the latter. According to simulations, losses in weed community diversity are reversible, especially when highly competitive species were eradicated allowing other species with lower lambda to increase their populations. However, the eradication of species with low reproductive rates reduced diversity and evenness. The effects of herbicide programs on the weed community lasted for several years even after those programs were modified indicating that seed banks play a major buffering role in the rate of change of weed community composition. Thus, frequent changes in management interrupting the repeated use of specific weed control programs, even under high herbicide intensity use (i.e., number of applications and mechanisms of action), can help maintain weed diversity in agroecosystems.

除草剂计划改变杂草种群密度以及杂草群落组成。重复使用给定程序可能会导致杂草群落逐渐变得更加难以管理或可能失去提供生态系统服务的能力。使用考虑到多个物种的种群动态的随机模型模拟这些变化，可以识别可能由使用给定除草剂程序引起的先验潜在群落变化。这项工作的目的是模拟不同除草剂方案下杂草物种的种群动态，以及这些动态如何随时间改变杂草群落多样性。使用不同除草剂计划下每个物种的种群增长率 (λ) 对十年内的杂草种群动态进行随机建模。Lambda 值是从长达八年的田间试验中获得的，这些值用于参数化每个杂草物种的模型的随机范围。十年来对每个物种的种群轨迹进行了建模，结果用于估计每种除草剂使用情景的丰富度、多样性和均匀度。单独重复使用草甘膦对丰富度的影响很小，但会导致杂草多样性和均匀度的大幅下降。具有更多作用机制和同时使用芽前和芽后除草剂的计划比使用单一或仅几种除草剂的计划更容易遭受杂草种类的损失。相反，前者比后者具有更高的保持杂草多样性和均匀度的概率。根据模拟，杂草群落多样性的损失是可逆的，特别是当高度竞争的物种被根除，允许其他 λ 较低的物种增加其种群时。然而，根除繁殖率低的物种降低了多样性和均匀性。除草剂计划对杂草群落的影响持续了几年，即使在这些计划被修改后，这表明种子库在杂草群落组成的变化率中起着主要的缓冲作用。因此，即使在高强度除草剂使用（即施用次数和作用机制）的情况下，管理的频繁变化也会中断重复使用特定杂草控制计划，这有助于保持农业生态系统中的杂草多样性。特别是当高度竞争的物种被根除，允许其他具有较低 lambda 的物种增加其种群时。然而，根除繁殖率低的物种降低了多样性和均匀性。除草剂计划对杂草群落的影响持续了几年，即使在这些计划被修改后，这表明种子库在杂草群落组成的变化率中起着主要的缓冲作用。因此，即使在高强度除草剂使用（即施用次数和作用机制）的情况下，管理的频繁变化也会中断重复使用特定杂草控制计划，这有助于维持农业生态系统中的杂草多样性。特别是当高度竞争的物种被根除，允许其他具有较低 lambda 的物种增加其种群时。然而，根除繁殖率低的物种降低了多样性和均匀性。除草剂计划对杂草群落的影响持续了几年，即使在这些计划被修改后，这表明种子库在杂草群落组成的变化率中起着主要的缓冲作用。因此，即使在高强度除草剂使用（即施用次数和作用机制）的情况下，管理的频繁变化也会中断重复使用特定杂草控制计划，这有助于维持农业生态系统中的杂草多样性。除草剂计划对杂草群落的影响持续了几年，即使在这些计划被修改后，这表明种子库在杂草群落组成的变化率中起着主要的缓冲作用。因此，即使在高强度除草剂使用（即施用次数和作用机制）的情况下，管理的频繁变化也会中断重复使用特定杂草控制计划，这有助于维持农业生态系统中的杂草多样性。除草剂计划对杂草群落的影响持续了几年，即使在这些计划被修改后，这表明种子库在杂草群落组成的变化率中起着主要的缓冲作用。因此，即使在高强度除草剂使用（即施用次数和作用机制）的情况下，管理的频繁变化也会中断重复使用特定杂草控制计划，这有助于维持农业生态系统中的杂草多样性。