This study compares species composition, abundance, biomass, and several other factors by which sedentary megafaunal and macrofaunal assemblages at depths between 14 m and 55 m on the Hueneme Shelf in southern California, USA, can be characterized. It details fundamental differences between these assemblages in this study area and demonstrates how little we know about a diverse range of attributes that are important in describing and evaluating infaunal assemblages. It provides strong support for a recent claim that: “The soft-sediment seafloor of the open continental shelf is among the least-known biomes on Earth, despite its high diversity and importance to fisheries and biogeochemical cycling” (Tomašových and Kidwell, 2017).

Basic and applied research after the 1950s transformed infaunal ecology from a discipline focused primarily on long-lived sedentary megafauna (analogous to ‘trees’ on land) into a field concentrating on opportunistic or ephemeral macrofauna (analogous to ‘weeds’ on land). Based on findings of this study, macrofaunal assemblages play a subordinate role in ecosystem dynamics. Most research in recent decades has overlooked contributions by sedentary megafauna. This focus leads to a poor understanding of the dynamics of these widespread ecosystems, severely undervalues their ecological importance and production, underestimates impacts of anthropogenic activities on unconsolidated sediments as well as the duration of recovery trajectories following disturbances.

Sedentary megafaunal and macrofaunal assemblages were quite different in virtually all aspects assessed during this analysis. Although macrofauna in this study had far greater species richness and were far more abundant than sedentary megafauna, conservative estimates for megafaunal biomass and secondary production indicate these organisms contribute substantially more energy to higher trophic levels than macrofauna. In addition, the megafaunal assemblages are characterized by many influential ‘ecosystem engineers’. Consequently, the differences in numbers of species and individuals are irrelevant with regard to determining value to the ecosystem. Megafauna in this area also exhibited more sensitivity in environmental factors. They live substantially longer than macrofauna, likely leading to greater stability in megafaunal assemblages. These differences indicate that current approaches focusing on macrofauna severely undervalue infaunal resources and contributions to higher trophic levels. They imply that studies of megafaunal assemblages should provide considerably greater insight into ecosystem dynamics and secondary production than macrofaunal assemblages and would have greater power to predict or assess environmental degradation or change, and document or predict recovery trajectories.

这项研究比较了物种组成，丰度，生物量以及其他几个因素，通过这些因素可以表征美国加利福尼亚南部惠尼姆架上14m至55m深度处的久坐大型真菌和大型真菌组合。它详细介绍了此研究领域中这些组合之间的根本区别，并说明了我们对描述和评估无用组合非常重要的各种属性知之甚少。它为最近的一项主张提供了有力的支持：“尽管大陆架开放，且对渔业和生物地球化学循环具有高度的多样性和重要性，但它是地球上鲜为人知的生物群落之一”（Tomašových和Kidwell，2017年） 。

1950年代后的基础和应用研究将不育生态学从主要侧重于长期久坐的久坐大型动物（类似于陆地上的``树木''）的学科转变为专注于机会性或临时性大型动物（类似于陆地上的``杂草''）的领域。根据这项研究的结果，大型动物群落在生态系统动力学中起次要作用。近几十年来的大多数研究都忽略了久坐的大型动物的贡献。这种关注导致人们对这些广泛的生态系统的动力学认识不足，严重低估了它们的生态重要性和产量，低估了人为活动对未固结沉积物的影响以及扰动后恢复轨迹的持续时间。

久坐的大型动物和大型动物的组合在此分析过程中评估的几乎所有方面都大不相同。尽管在这项研究中大型动物比久坐的大型动物具有更大的物种丰富度和丰富度，但是保守估计大型动物的生物量和次级生产表明，这些生物比大型动物为更高的营养水平贡献了更多的能量。此外，大型动物群落的特征是许多有影响力的“生态系统工程师”。因此，物种和个体数量的差异与确定生态系统的价值无关。该地区的大型动物也对环境因素表现出更高的敏感性。它们的生活比大型动物更长，可能导致大型动物组合的稳定性更高。这些差异表明，目前针对大型动物的方法严重低估了无用资源的价值，并导致较高的营养水平。他们暗示，与大型动物群落相比，大型动物群落的研究应提供对生态系统动力学和次级生产的更大的洞察力，并且具有更大的预测或评估环境退化或变化以及记录或预测恢复轨迹的能力。