Breakpoint phenological responses in high-Arctic arthropods

Many arthropod species show earlier seasonal activity trends with warming, but these responses cannot continue indefinitely. Beyond a threshold, phenological responses may no longer keep pace with climate change. While many studies estimate linear phenological responses to climate, few test for breakpoint responses. Here, across a 28-year time series, we examined linear and breakpoint responses to temperature and snowmelt across 15 arthropod taxa in seven plots from high-Arctic Greenland, a region experiencing pronounced warming. Our meta-analysis revealed support for a breakpoint response in two of six phenological driver and event combinations. This breakpoint response was found in the onset and peak of activity to the timing of snowmelt, where activity advanced with snowmelt until a threshold, after which the relationship levelled off. While we also found a breakpoint response in peak phenology to temperature, this disappeared when controlling for snowmelt in the model, underscoring ..., , , # Keeping up with climate change - have Arctic arthropods reached their phenological limits?

## Description of the data and file structure

This repository contains the code and data necessary to replicate data analyses, figures, and tables in:

***Keeping up with climate change - have Arctic arthropods reached their phenological limits?***

## Data usage guidelines

### *Note on data provenance and licensing:*

This dataset includes original data and materials created by the authors, which are released under the Creative Commons Zero (CC0 1.0) Public Domain Dedication. These original contributions are free to use without restriction.

##### File: df\_phenology\_metrics

###### Description: Estimated phenological metrics (onset, peak, and end of annual activity) for all arthropod taxa sampled across years and plots at Zackenberg, Northeast Greenland.

###### *Variables*

* **Year**: Year of sampling.
* **Plot**: Vegetation type in which arthropods were sampled.
* **SpeciesID**: Arthrop...,