DOI: 10.5061/dryad.8kprr4xz3
title: Grazing and mowing practices drive complex dynamics in the structure of butterfly communities in semi-natural grasslands

description: Rural abandonment and agricultural intensification are major threats to
 the conservation of biodiversity in Europe. Butterflies are excellent
 bioindicators of environmental change and can be used to assess the impact
 of global change on agroforestry mosaics. We used long-term
 spatio-temporal butterfly data to explore how grazing and mowing practices
 affect butterfly communities in the Northwest Mediterranean Basin. Changes
 in butterfly richness, abundance and habitat indicators were recorded
 using standardized transect counts. We focused primarily on the impact of
 management practices but also considered their interaction with other
 drivers (climate and habitat configuration). The most intensive levels of
 grazing did not correspond to the lowest butterfly richness; rather, they
 were correlated with lower abundances but supported a greater number of
 open habitat specialists. More intense mowing was also associated with low
 abundances and communities dominated by common and open-habitat species.
 Habitat configuration variables were also influential: open areas favoured
 greater butterfly richness and abundance, as well as more grassland
 specialists; greener vegetation, as measured by satellite imagery, led to
 an increase in butterfly abundance and communities composed of more
 generalist and forest species. Our study demonstrates the significant
 impact of grassland management on butterfly communities and offers
 insights into adaptive rangeland practices. It also indicates that
 increased levels of mowing and grazing can alter the composition of
 butterfly communities without necessarily affecting their diversity. This
 suggests that a dynamic restructuring of butterfly communities may occur
 in response to the environmental and habitat changes induced by these
 practices.
description: This dataset contains annual environmental and ecological data
 collected from 1993 to 2021. It includes variables related to vegetation
 cover, such as the Soil-Adjusted Vegetation Index (SAVI), derived from
 Landsat satellite imagery, and open vegetation cover obtained from the
 Corine Land Cover database. Land management practices, including grazing
 and mowing occurrences, were sourced from the citizen science project of
 the Catalan Butterfly Monitoring Scheme (CBMS). Biodiversity is
 represented by butterfly abundance and species richness, also collected
 through the CBMS, serving as key indicators of ecological health.
 Additionally, climatic variables such as rainfall, temperature, and
 aridity index, sourced from the Digital Climatic Atlas of Catalonia,
 provide insights into the site's environmental conditions over time.
 The dataset also incorporates butterfly-based ecological indicators,
 including the Community Specialization Index (CSI) and the TAncat- Obert
 index (TAOC), reflecting habitat preferences for open or closed
 environments.
description: # Grazing and mowing practices drive complex dynamics in the structure of
 butterfly communities in semi-natural grasslands
 [https://doi.org/10.5061/dryad.8kprr4xz3](https://doi.org/10.5061/dryad.8kprr4xz3) ## Description of the data and file structure ### Files and variables #### File: Dryad\_data.xlsx **Description:** Data of the variables used to generate the  Generalized linear mixed models. ##### Variables * **Itin / Secc:** Identifiers for the itinerary and section where the data was collected. * **Year:** Year of data collection (1993-2022). * **MEAN_SAVI / SD_SAVI:** Mean and standard deviation of the **Soil-Adjusted Vegetation Index (SAVI)**, an indicator of vegetation cover. * **Grazing_occurrence**: Percentage of grazing detection between March and September. * **Mowing_occurrence:** Mowing index, calculated by multiplying the number of mowing events detected in a year by the percentage of grassland cover. Not ever mowed sections had NA, and not mowed sections in a specific year had 0.  * **Aperture_index**: A metric indicating the openness or closeness of the habitat in relation to plant cover * **CSI (Community Specialization Index):** Index measuring the habitat spezilization of the community. * **TAOC:** Index measuring communtiy preference for open or closed habitat. * **Butterfly_abundance / Butterfly_Richness:** Abundance and richness of butterflies in the study area. * **Yearly_Mowing :** Annual mowing frequency. Not ever mowed sections had NA, and not mowed sections in a specific year had 0.  * **Open_vegetation_cover**: Open vegetation cover percentage. * **Rainfall:** Annual precipitation (in millimeters). * **Temperature:** Annual average temperature (°C). * **Aridity:** Aridity index, derived from the relationship between temperature and precipitation. * **CODE:** Site identifier code. ## Code/software We used **Generalized Linear Mixed Models (GLMMs)** to analyze how grazing and mowing occurrences influence the long-term spatio-temporal dynamics of butterfly communities. The analyses were conducted in **R** using the **lme4** package, which allows for the fitting of mixed-effects models to account for both fixed and random effects in the data. ## Access information Data was derived from the following sources: * CBMS: [https://www.catalanbms.org/ca/](https://www.catalanbms.org/ca/) * Corine Land Cover: [https://land.copernicus.eu/en/products/corine-land-cover](https://land.copernicus.eu/en/products/corine-land-cover) * Digital Climatic Atlas of Catalonia: [https://opengis.grumets.cat/wms/iberia/espanol/es_presentacio.htm](https://opengis.grumets.cat/wms/iberia/espanol/es_presentacio.htm)