DOI: 10.5061/dryad.n5tb2rbzw
title: Data from: Emergent spatial patterns can indicate upcoming regime shifts in a realistic model of coral community

description: Increased stress on coastal ecosystems, such as coral reefs, seagrasses,
 kelp forests and other habitats can make them shift towards degraded,
 often algae-dominated or barren communities. This has already occurred in
 many places around the world, calling for new approaches to identify where
 such regime shifts may be triggered. Theoretical work predicts that the
 spatial structure of habitat-forming species should exhibit changes prior
 to regime shifts, such as an increase in spatial autocorrelation. However,
 extending this theory to marine systems requires theoretical models
 connecting field-supported ecological mechanisms to data and spatial
 patterns at relevant scales. To do so, we built a spatially-explicit model
 of sub-tropical coral communities based on experiments and long-term
 datasets from Rapa Nui (Easter Island, Chile), to test whether spatial
 indicators could signal upcoming regime shifts in coral communities.
 Spatial indicators anticipated degradation of coral communities following
 increases in frequency of bleaching events or coral mortality. However,
 they were generally unable to signal shifts that followed herbivore loss,
 a widespread and well-researched source of degradation, likely because
 herbivory, despite being critical for the maintenance of corals, had
 comparatively little effect on their self-organization. Informative trends
 were found both under equilibrium and non-equilibrium conditions, but were
 determined by the type of direct neighbor interactions between corals,
 which remain relatively poorly documented. These inconsistencies show that
 while this approach is promising, its application to marine systems will
 require detailed information about the type of stressor, and filling
 current gaps in our knowledge of interactions at play in coral
 communities.
description: This archive contains various tables related to experiments and
 censuses carried out at Rapa Nui (Easter Island) between 1999 and
 2014:  Long-term observational data
 (comm_monitoring.txt), describing changes in community composition in
 various sites around the island  Quadrat-based
 surveys recording the density of urchins on various substrates, at
 different sites around the island (diadema_general_density.txt and
 diadema_microhabitat_density.txt) Results from an
 exclusion experiment (monitoring_experiment.txt)involving the removal of
 coral and algae on a small surface, along with the monitoring of their
 regrowth on the same surface under various grazing treatments
 (presence/absence of fish and urchins) Results from
 an experiment involving monitoring the regrowth of algae after scraping a
 small quadrat within an established patch
 (scraping_experiment.txt) Data on urchin body sizes,
 based on 68 individuals (urchin_size_weight_relationship.txt,
 urchin_mean_body_sizes.txt), classified into
 recruits/juveniles/adults These data
 support running model simulations, which can be re-run at any time.
 However, because these take a lot of time to run (day-weeks), the
 intermediate results have been saved into "./cached_results" as
 R data files.
description: This dataset contains a set of tables which are in tab-separated
 format (in "./data_export/"). Alternatively, the same tables can
 be read from R data file (saved in R 4.2.0), in the folder
 "./data". The code included with this package
 is divided into the model code which is used to run the simulations
 supporting the paper's conclusions (in "model_code"), along
 with a few R/Rmarkdown scripts which are used to dissect the results and
 produce the figures (in "./analyses").