The purpose of this experiment was to investigate the survival and biomass accumulation of wetland plant species under different water depths in controlled microcosms. In the greenhouse, two-weekold seedlings were randomly assigned to one of seven water-depth treatments (Ϫ6, Ϫ4, Ϫ2, 0, ϩ2, ϩ4, and ϩ6 cm relative to the soil surface) and allowed to grow for six months. Species included five perennial sedges, four perennial and one annual grasses, and two perennial and two annual forbs. Twelve of the species had their lowest biomass and lowest survivorship at water depths greater than 0 cm. The root:shoot ratio, however, did not change across water-depth treatments. Biomass accumulation differed by plant form (sedg-esϾforbsϾgrasses). Annuals had the greatest biomass values across the widest range of water depths compared to perennials. Of the fourteen plants tested, Lythrum salicaria (purple loosestrife), one of the two invasive, non-native species tested, had the greatest biomass at water depths from Ϫ6 to ϩ2, whereas Phalaris arundinacea (reed canarygrass), the other invasive, had comparatively small mean biomass values. Ranking of biomass between species was highly concordant between non-flooded treatments but not significantly concordant between flooded treatments indicating that plant species have distinct responses to flooding. This research suggests that newly established plant seedlings in wetland restorations should not be submerged, or if submergence is unavoidable, annuals and sedges may be more tolerant of prolonged flooding.

We implemented and institutionalized an adaptive management (AM) process for the Columbia Estuary Ecosystem Restoration Program, which is a large-scale restoration program focused on improving ecosystem conditions in the 234-km lower Columbia River and estuary. For our purpose, "institutionalized" means the AM process and restoration programs are embedded in the work flow of the implementing agencies and affected parties. While plans outlining frameworks, processes, or approaches to AM of ecosystem restoration programs are commonplace, their establishment for the long-term is not. This article presents the basic AM process and explains how AM was implemented and institutionalized. Starting with a common goal, we pursued a well-understood governance and decision-making structure, routine coordination and communication activities, data and information sharing, commitment from partners and upper agency management to the AM process, and meaningful cooperation among program managers and partners. The overall approach and steps to implement and institutionalize AM for ecosystem restoration explained here are applicable to situations in which it has been incomplete or, as in our case, the restoration program is just getting started.

Ecological restoration programs in dynamic coastal environments can benefit from adaptive management, including an iterative process for identifying and addressing critical uncertainties. We highlight key developments under the three pillars that have increased the rate of restoration by the Columbia Estuary Ecosystem Restoration Program (CEERP) over 20 years: science, coordination, and management. We show how such programs can be institutionalized to ensure that estuary ecosystems are better understood, conserved, and restored. The principal conservation effort under CEERP is to reconnect historical floodplain wetlands to the mainstem. The program also supports other restoration actions that demonstrate a high potential to benefit ecosystem function and endangered salmon populations; however, there is greater uncertainty regarding these less-utilized techniques. Through adaptive management, we address technical uncertainty regarding benefits to the environmental resource and programmatic uncertainty pertaining to decision-making. Here, we examine three periods of CEERP growth to establish how complementary research and restoration actions have improved program outcomes over time. We highlight the tools and processes that were developed and integrated into the program to refine program strategy, improve project design, and maximize ecological benefits. CEERP supported 77 restoration projects and reconnected over 7,000 acres of floodplain habitat to the lower Columbia River between 2004 and 2021. Building on these successes, we outline current plans to better engage landowners and local communities, solicit new project types, and maintain enough flexibility within the program to adapt to new priorities.

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