# PhenoStras2022: A 2022 smartphone-based image and field phenology dataset for monitoring urban trees in Strasbourg, France

## TL;DR

PhenoStras2022 is a smartphone-based dataset capturing urban tree phenology in Strasbourg, France, to support climate resilience and monitoring.

## Contribution

The dataset introduces a low-cost, replicable protocol for urban tree phenology using smartphones and standardized observations.

## Key findings

- PhenoStras2022 provides ground-based data across 40 green sites in Strasbourg for a full phenological cycle.
- The dataset includes Digital Hemispherical and Front-View Photography alongside simplified BBCH scale observations.
- It supports remote sensing validation and urban climate studies while promoting participatory science.

## Abstract

Urban trees provide critical ecosystem services but remain vulnerable to climate change and urban environmental stresses. To improve understanding of their phenological dynamics and support reproducible urban vegetation monitoring, PhenoStras2022 is introduced, a dataset based on non-destructive, low-cost (using a portable smartphone-based setup) ground-based observations. Data were collected throughout a complete phenological cycle in 2022 across 40 green sites in Strasbourg, France. Two types of photographic acquisitions were conducted: Digital Hemispherical Photography (DHP) and Front-View Photography (FVP), complemented by field-based phenological observations following a simplified BBCH scale. The dataset is organized to enable a range of applications, including remote sensing products validation and urban climate studies. PhenoStras2022 addresses the current lack of ground-based urban phenology data and provides a robust foundation for analysing seasonal patterns and the resilience of urban trees. It also promotes participatory science by offering an accessible, replicable acquisition protocol, contributing to the strengthening of phenological monitoring networks in the context of a changing climate.