Methods for broad-scale plant phenology assessments using citizen scientists' photographs.

Vijay V Barve,Daniel J Paluh,Brian J Stucky,Robert P Guralnick,Michael W Belitz,Jessica A Oswald,Maggie M Hantak,Bryan S Mclean,Daijiang Li,Ryan A Folk,Laura Brenskelle,Narayani V Barve

doi:10.1002/aps3.11315

Abstract

PremiseCitizen science platforms for sharing photographed digital vouchers, such as iNaturalist, are a promising source of phenology data, but methods and best practices for use have not been developed. Here we introduce methods using Yucca flowering phenology as a case study, because drivers of Yucca phenology are not well understood despite the need to synchronize flowering with obligate pollinators. There is also evidence of recent anomalous winter flowering events, but with unknown spatiotemporal extents.MethodsWe collaboratively developed a rigorous, consensus‐based approach for annotating and sharing whole plant and flower presence data from iNaturalist and applied it to Yucca records. We compared spatiotemporal flowering coverage from our annotations with other broad‐scale monitoring networks (e.g., the National Phenology Network) in order to determine the unique value of photograph‐based citizen science resources.ResultsAnnotations from iNaturalist were uniquely able to delineate extents of unusual flowering events in Yucca. These events, which occurred in two different regions of the Desert Southwest, did not appear to disrupt the typical‐period flowering.DiscussionOur work demonstrates that best practice approaches to scoring iNaturalist records provide fine‐scale delimitation of phenological events. This approach can be applied to other plant groups to better understand how phenology responds to changing climate.

Highlights

PREMISE: Citizen science platforms for sharing photographed digital vouchers, such as iNaturalist, are a promising source of phenology data, but methods and best practices for use have not been developed
Excluding Y. elata, we found that aging effort from 11 trained volunteers the percentage of the target Yucca species in flower on iNaturalist who each scored between 2000 and 3000 images for all three ranged from 16–26%
We note that iNaturalist itself has reporting mechanisms for plant phenology, so a longer-term goal is to assure that scoring efforts work in both directions, such that annotations can be fed back to iNaturalist, and to encourage further effort to denote phenology by the more than 500,000 citizen scientists who contribute to that platform

Summary

Introduction

PREMISE: Citizen science platforms for sharing photographed digital vouchers, such as iNaturalist, are a promising source of phenology data, but methods and best practices for use have not been developed. There is evidence of recent anomalous winter flowering events, but with unknown spatiotemporal extents

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