Avian diversity and trait dataset from native and non-native tree stands across Central Europe
Description
This dataset contains plot-level environmental variables, bird community records, and standardized breeding-evidence categories collected in native and non-native forest stands in the northernmost Pannonian Basin (western Slovakia). Data were collected during two breeding seasons (2023–2024) using a standardized point-count protocol applied in a twin-plot design, where each native stand was paired with a nearby non-native stand dominated by Robinia pseudoacacia (black locust) or Populus × euramericana clone I-214 (hybrid poplar). Table 1 provides plot-level descriptors, including stand origin, age, tree-species composition, slope, aspect, elevation, and geographic coordinates. Table 2 lists all bird observations from point counts, including species identity, abundance, plot codes, survey timing, and species-level ecological traits (body size, clutch size, number of broods, incubation period, lifespan, nest type, migration strategy, and diet). Table 3 contains explanation of a standardized scheme for classifying breeding evidence, covering categories from possible to confirmed breeding based on behavioral and nest-related criteria. This dataset supports spatial and temporal analyses of forest bird communities across matched twin-plots that differ in tree-species composition (near-natural vs. non-native) but share similar structural conditions (age, slope, aspect, elevation). Explanations: Table 1: Code – twin-plot identifier; Age – average age of dominant tree species; Composition – proportion of dominant species (abbreviations: BL = Robinia pseudoacacia; BA = Alnus glutinosa; BP = Populus nigra; EA = Fraxinus excelsior; EB = Fagus sylvatica; EH = Carpinus betulus; EO = Quercus robur; ES = Populus tremula; EWE = Ulmus laevis; FE = Ulmus minor; FM = Acer campestre; I-214 = Populus × euramericana I-214; SL = Tilia cordata; SO = Quercus petraea; SP = Pinus sylvestris; WP = Populus alba; WW = Salix alba; SCH = Cerasus avium). Table 2: Code – twin-plot identifier; Origin – N = native, A = alien (non-native); Abundance – number of individuals; Breeding category – A = possible, B = probable, C = confirmed, M = migration/overflight; ecological traits as listed above. Table 3: Breeding categories (A–C), their codes, and assigned field-based criteria.
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Steps to reproduce
Bird surveys were conducted using a standardized point-count method during two consecutive breeding seasons (2023–2024) in native forest plots with natural tree-species composition, each paired with a nearby non-native plot dominated by black locust (Robinia pseudoacacia; 26 plots) or the hybrid poplar clone Populus × euramericana I-214 (14 plots). Each plot was surveyed up to three times between mid-March and late May, corresponding to the peak breeding period for most Central European bird species. During each visit, all detected bird species and their abundances were recorded, and breeding evidence was assigned to categories ranging from possible to confirmed based on behavioral and nest-related indicators. Surveys were conducted in early morning hours (05:00–10:00) under suitable weather conditions, avoiding rain and strong winds. Species-level life-history traits (body size, clutch size, number of broods, incubation period, lifespan, nest type, migration strategy, and diet) were obtained from published trait databases for European birds.Plot selection was based on remote-sensing data and forestry maps. Each native plot was matched with a non-native counterpart by forest origin, stand age (average age of dominant tree species), tree-species composition, canopy cover, slope, aspect, and elevation to minimize environmental variability. Information on plot origin, forest age, and composition was taken from forestry maps. Only stands ≥40 years old were included to ensure structural comparability and avoid the influence of early successional stages; stand age refers to the dominant tree species rather than every individual. Native and non-native stands had to contain at least 70% native or non-native tree species, respectively, and a minimum canopy cover of 50%, estimated by field experts. Topographic variables (slope, aspect, elevation) were derived from the Digital Terrain Model of Slovakia. Distances between paired plots ranged from 300 to 600 m to avoid double counting individual birds while maintaining comparable environmental conditions. All plots were located at least 50–100 m from the nearest forest edge to minimize edge effects.
Institutions
- Univerzita Komenskeho v Bratislave Prirodovedecka fakulta
Categories
Funders
- Slovak Scientific Grant Agency VEGAGrant ID: 2/0097/22