Dataset and Replication Code for “Insects Associated with Declining Riparian Black Alder (Alnus glutinosa) Stands: Assemblage Structure, Seasonality, and the Role of Microhabitats in the Valleys of the Utrata and Łutownia Rivers”

This repository contains the primary analytical input, replication code, and selected derived outputs supporting the community-level analyses reported in the associated manuscript on insect assemblages associated with declining riparian black alder stands in the valleys of the Utrata and Łutownia rivers, Poland. The deposit is designed as a compact reproducibility package: it includes the cleaned analytical matrix, the metadata required to interpret that matrix, and machine-readable outputs needed to verify the published diversity, beta-diversity, NMDS, and rarefaction/extrapolation results.

Files included:
Insects_list.xlsx — Primary input file containing the taxon abundance data arranged by river and distance classes used by the replication workflow.
Replication_Code.R — R script that reads the input data, performs the community-level analyses, and generates the reproducible outputs deposited in this repository.
clean_species_by_stratum.csv — Cleaned taxon-by-stratum abundance matrix used as the principal analytical dataset for the published results.
sample_metadata.csv — Metadata table linking each analytical stratum to river identity and distance from the channel margin.
taxon_lookup.csv — Lookup table linking analytical taxon identifiers to the reported taxonomic names used in the study.
diversity_bootstrap_CI_long.csv — Full bootstrap output for richness, diversity, evenness, and sample-coverage metrics by stratum.
beta_pairwise_long.csv — Complete pairwise Sørensen beta-diversity table, including turnover and nestedness components, for all stratum combinations.
nmds_site_scores.csv — Coordinates of the six analytical strata in the exploratory NMDS ordination.
nmds_species_scores.csv — Taxon scores from the exploratory NMDS ordination for interpretive use outside the main text.
rarefied_richness_to_min_N.csv — Rarefied richness estimates standardised to the smallest observed stratum abundance.
iNEXT_AsyEst.csv — Asymptotic richness and diversity estimates generated by iNEXT.
iNEXT_iNextEst.csv — Interpolation and extrapolation estimates generated by iNEXT across sample-size and coverage gradients.
nmds_diagnostics.txt — Diagnostic summary for the NMDS solution, including stress and dimensionality.
README_dataset.txt — Plain-text repository guide containing the title, repository description, and reproduction instructions.

The repository does not prioritise technical helper files used only for column detection, automatically regenerated distance matrices, or figure files already shown in the manuscript. These products can be recreated directly from Insects_list.xlsx and Replication_Code.R, so the deposited package remains concise while still fully supporting verification, re-use, and re-analysis.