Prolonged flow intermittency undermines the habitat potential of forested landscapes for a stream-dwelling dragonfly
Data files
Aug 12, 2025 version files 42.13 KB
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combined_df_merged_FIN5_tab.csv
11.31 KB
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combined_df_merged_FIN5_xl.xlsx
25.33 KB
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README.md
5.48 KB
Abstract
Understanding how land use and variability of the hydrological regime jointly shape species distributions is essential for the conservation of aquatic insects in increasingly intermittent streams. We investigated how flow intermittency influences the relationship between land use and the occurrence probability of Cordulegaster heros in a drying river network. Field surveys were conducted at 42 stream sites in southwestern Hungary over a two-year period. We combined species presence–absence data with land use variables and hydrological proxies. Statistical analyses included decision tree modeling and binomial generalized linear models. C. heros was associated with forested landscapes and absent from sites with prolonged zero-flow periods or high agricultural land use. Occurrence probability declined markedly when forest cover was low or when dry periods were extended in duration. Although C. heros larvae can tolerate short-term drying by burrowing into sediments, prolonged flow intermittency and reduced landscape connectivity may limit both survival and recolonization. Our findings underscore the need for conservation strategies that jointly address land use and hydrological conditions to counter the rising flow intermittency expected with ongoing climate change.
Dataset DOI: 10.5061/dryad.dfn2z35dw
Description of the data and file structure
Files :
combined_df_merged_FIN5_xl.xlsx
combined_df_merged_FIN5_tab.csv
Descriptions of the files
combined_df_merged_FIN5_xl.xlsx - an Excel dataset with a description of the variables
combined_df_merged_FIN5_tab.csv - same tabular dataset
Descriptions of the variables
| name | description | variable description | unit |
|---|---|---|---|
| SITE | code | SITE code | |
| KM | code | SITE code numerical | |
| PRESENCE | Biological | Presence of Cordulegaster heros | 1 True; 0 False |
| zeros | hydrological proxy | the total number of dry days | days |
| long_zero_runs | hydrological proxy | the number of consecutive dry periods over 30 days | days |
| longest_zero_runs | hydrological proxy | the longest consecutive dry periods in days | days |
| zero_runs | hydrological proxy | the number of consecutive dry periods | days |
| average_zero_runs | hydrological proxy | the average duration of dry periods in days | days |
| mesterseges | land use | artificial | percentages |
| agriculture | land use | agriculture | percentages |
| gyep | land use | grassland | percentages |
| forest | land use | forest | percentages |
| bukk | land use | beech | percentages |
| gyerty_kocs | land use | hornbeam-oak | percentages |
| cser | land use | shrub | percentages |
| TBVF_os | land use | riparian forest (softwood) | percentages |
| elegyes | land use | mixed | percentages |
| tulevelu | land use | coniferous | percentages |
| akac | land use | black locust | percentages |
| feluj | land use | regenerated | percentages |
| nem_besorol | land use | unclassified | percentages |
| oshonos | land use | native | percentages |
| nem_oshonos | land use | non_native | percentages |
| zavart_erdo | land use | disturbed_forest | percentages |
| mesolithal | habitat | mesolithal | percentages |
| microlithal | habitat | microlithal | percentages |
| akal | habitat | akal (boulder–cobble substrate) | percentages |
| psammal | habitat | psammal (sand substrate) | percentages |
| argyllal | habitat | argyllal (clay substrate) | percentages |
| xylal | habitat | xylal (wood substrate) | percentages |
| CPOM | habitat | CPOM (coarse particulate organic matter) | percentages |
| FPOM | habitat | FPOM (fine particulate organic matter) | percentages |
| living parts of terrestrial plants | habitat | living parts of terrestrial plants | percentages |
| slope | hydromorphology | slope | degrees |
| elev | hydromorphology | elevation | m |
| aspect_2 | hydromorphology | aspect_2 | degrees |
