Native cover crops enhance biodiversity and ecosystem services in hazelnut orchards

Agroecological restoration aims to restore biodiversity and ecosystem function in agricultural landscapes while sustaining crop production. Adopting native plants as cover crops may restore ecological value to cropping systems such as nut orchards. We focused on Oregon hazelnut orchards and compared how four seed mixes (native annuals, native perennials, conventional cover crops, and unseeded controls) performed under three levels of orchard floor disturbance (flailing, flailing and scraping, and unmanaged/none) across three different orchard ages with corresponding differences in canopy shade over a two-year period. We evaluated cover crop performance by three criteria: the survival criteria (response to disturbance and shading), the production criteria (effects on weeds, erosion potential, and soil moisture) and the ecological functioning criteria (abundance and diversity of native plants and pollinator visitations). We found that native species generally outperformed conventional cov..., Data collection
To evaluate cover crop survival, we visually estimated percent cover of each species at peak biomass in May 2020 and 2021. To quantify shading, we measured the canopy cover of each subplot in July each year using Canopeo (Patrignani & Ochsner 2015), a mobile application that analyzes fractional green canopy cover from digital images. Imagery was gathered in July 2020 at the subplot-level by taking upward-facing photos at chest height. This was repeated in July 2021, following an ice storm in February 2021 that broke tree limbs and reduced canopy cover, especially in the 40-year-old orchard. Because shading in a portion of the 15-year-old orchard was increased by rows of taller vegetation to the south (Figure S1) we estimated the proportion of plots that were in shade from adjacent trees at noon during mid-spring monitoring. Dense shade affected approximately 60% of three plots, leading us to calculate canopy cover as a weighted average within the subplot (40%) and th..., , # Data from: Native cover crops enhance biodiversity and ecosystem services in hazelnut orchards

[https://doi.org/10.5061/dryad.9ghx3fft0](https://doi.org/10.5061/dryad.9ghx3fft0)

## Description of the data and file structure

We experimentally tested native cover crops as a tool for agroecological restoration in Oregon hazelnut orchards, with an eye toward restoring oak-prairie understory species and associated pollinators. Because of farmland development in the fertile Willamette Valley, oak-prairie communities are limited to marginal sites representing 2% of their historical range (Wright 2020). New orchards, which are rapidly increasing (NASS 2017), have open canopies that mirror those of open prairies, while established orchards share similar canopy structure to oak woodlands. First, we examined which species of native annual and perennial cover crops can survive (Figure 1a; survival criteria), considering how orchard floor management and canopy shade affect survival. Second, we ...