A principle shared by both economists and ecologists is that a diversified portfolio spreads risk, but this idea has little empirical support in the field of population biology. We found that population growth rates (recruits per spawner) and lifehistory diversity as measured by variation in freshwater and ocean residency were negatively correlated across short time periods (one to two generations), but positively correlated at longer time periods, in nine Bristol Bay sockeye salmon populations. Further, the relationship between variation in growth rate and life-history diversity was consistently negative. These findings strongly suggest that life-history diversity can both increase production and buffer population fluctuations, particularly over long time periods. Our findings provide new insights into the importance of biocomplexity beyond spatio-temporal aspects of populations, and suggest that maintaining diverse life-history portfolios of populations may be crucial for their resilience to unfavourable conditions like habitat loss and climate change.

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In this article, we describe a method for predicting floodplain locations and potential lateral channel migration across 82,900 km (491 km2 by bankfull area) of streams in the Columbia River basin. Predictions are based on channel confinement, channel slope, bankfull width, and bankfull depth derived from digital elevation and precipitation data. Half of the 367 km2 (47,900 km by length) of low‐gradient channels (≤ 4% channel slope) were classified as floodplain channels with a high likelihood of lateral channel migration (182 km2, 50%). Classification agreement between modeled and field‐measured floodplain confinement was 85% (κ = 0.46, p < 0.001) with the largest source of error being the misclassification of unconfined channels as confined (55% omission error). Classification agreement between predicted channel migration and lateral migration determined from aerial photographs was 76% (κ = 0.53, p < 0.001) with the largest source of error being the misclassification of laterally migrating channels as non‐migrating (35% omission error). On average, more salmon populations were associated with laterally migrating channels and floodplains than with confined or nonmigrating channels. These data are useful for many river basin planning applications, including identification of land use impacts to floodplain habitats and locations with restoration potential for listed salmonids or other species of concern.

Floodplains are some of the most ecologically important and human-impacted habitats throughout the world. Large efforts are underway in North America, Europe, Australia, and elsewhere to restore floodplain habitats, not only to increase fish and aquatic biota but to restore ecological diversity. As the scale, number, and complexity of floodplain restoration projects has increased, so has the need for rigorous monitoring and evaluation to demonstrate effectiveness and guide future floodplain restoration efforts. Moreover, technological advances in remote sensing, genetics, and fish marking have been evolving rapidly and there is need to update guidance on the best methods for monitoring physical and biological response to floodplain restoration. A comprehensive review of the restoration literature located 180 papers that specifically examined the effectiveness of various floodplain restoration techniques. The various methods that were historically and currently used to evaluate the physical (channel and floodplain morphology, sediment, flow, water quality [temperature and nutrients]) and biological (fish, invertebrates, and aquatic and riparian plants) effectiveness of floodplain restoration were reviewed and used to provide recommendations for future monitoring. For each major physical and biological monitoring method, we discuss their importance, how they have historically been used to evaluate floodplain restoration, newer methodologies, and limitations or advantages of different methodologies and approaches. We then discuss monitoring the effectiveness of small (<2 km in main channel length) and large (>2 km of main channel length) floodplain projects, with recommendations for various study designs, parameters, and monitoring methodologies.