DOI: 10.7291/d1jh5n
title: Ecosystem functions of plant diversity: Comparisons from a large-scale marsh restoration experiment in California, USA

description: Although the promotion of biodiversity has been recognized as an important
 conservation goal, salt marsh restoration typically focuses on
 re-establishing dominant foundation species. Salt marsh restoration
 projects that add or remove sediment to optimize marsh elevation often
 result in a bare landscape following construction. Restoration managers
 must decide whether to plant and, if so, which species. This decision can
 be difficult because few studies have examined the ecological functions of
 individual species, especially those that are less abundant. Within a
 major salt marsh restoration project in Elkhorn Slough, California, where
 17,000 plants of five high marsh species were planted, we investigated how
 rarer species and the naturally recruiting dominant (Salicornia pacifica)
 differ in ecosystem function. We evaluated 31 different metrics related to
 blue carbon, plant productivity, environmental effects, and community
 interactions. No single species had the greatest ecological function
 across this suite of metrics, and measured effects were mainly
 independent, with only 16 of 435 pairwise comparisons revealing a strong
 correlation. We found significant differences among species for 18
 metrics, revealing key contrasts in ecosystem function, with significant
 effects of marsh elevation and interaction between effects of species and
 elevation on some of these functions. Salicornia pacifica scored highest
 for metrics such as recruitment and canopy height but other species
 outperformed Salicornia in other metrics. Frankenia salina had the
 greatest ecological function in the highest number of metrics, including
 cover and belowground biomass carbon content, but other species had higher
 rates of photosynthesis and harbored fewer individuals of invasive
 arthropods. We recommend planting a suite of less common species at
 restoration sites to provide more diverse functions across the landscape.
 Frankenia salina in particular is recommended for its tolerance of
 hypersalinity and low moisture conditions. Our demonstration of the value
 of complementing restoration of the dominant foundation species with
 restoration of less common species is applicable to restoration of other
 ecosystems beyond salt marshes. The approach we implemented, evaluating a
 large suite of functions for multiple species across a restored landscape,
 can serve as a model for investigations of the importance of biodiversity
 for enhancing multifunctionality in other restored
 ecosystems.  
description: Data was collected through a variety of methods such as
 collecting aboveground plant biomass, deploying in-growth bags, deploying
 teabags, and utilizing a spectroscopy greenhouse gas analyzer. A complete
 description of the study objectives, methods, field sites, and uses of
 these data for analyses and interpretations can be found in the associated
 (forthcoming) paper, Shikuzawa et al, 2023. Raw data with outliers removed
 (when indicated in the associated paper), are provided. 
description: Excel is required for opening the datasets.