Chudomelová, Zelený & Li (2019)

We established a square plot of 100 × 100 m with 100 subplots of 2 × 2 m. The subplots were organized in a regular grid with 10-m lags between adjacent subplots. At each 2 × 2 m subplot, we recorded a list of vascular plant species along with visual estimates of species cover using the nine-degree Braun-Blanquet scale (Westhoff & van der Maarel 1978). Woody seedlings and saplings were later excluded from the analyses. In the center of each subplot, we took a hemispherical photograph of the canopy at the height of 1.3 m (using Nikon Coolpix 4500 camera with FC-E8 fishey lens). We also measured the slope inclination (using Silva ClinoMaster), aspect (using compass) and relative elevation of each subplot using the Field-Map device (IFER, Ltd., Jílové u Prahy, Czech Republic) with accuracy up to 0.2 m. At four locations within each subplot, we measured the soil depth using 30 cm long iron probe, and collected a mixed soil sample from the top 5 cm.

Sampling design within the 1-ha permanent plot (from the Appendix B of Chudomelová et al. 2017).

An example of a 2 m × 2 m sampling plot (photo credit: David Zelený).

The study took place in a thermophilous oak forest dominated by Quercus petraea. The forest is located close to the village of Němčičky, south Moravia, Czech Republic, in low hills at the fringe of the flysch Carpathians (48.948° N, 16.837° E). The sampling area spreads over the upper part of an inconspicuous hill (322 m a.s.l.), in a forested complex surrounded by arable fields and pastures. The most prominent feature of the site is a pronounced fine-scale heterogeneity of soil pH and related variables (Ca and Mg concentration, conductivity, C:N). Although built of flysch, the hill is covered in partly decalcified loess deposits. The pH values can differ up to two units over a distance of 5 m (e.g. from about 5 to above 7) and the character of the ground herb layer obviously relates to them: patches with base-rich soil are densely overgrown by herb understorey, whereas patches with acid soil are almost bare. (From Chudomelová & Zelený, 2020).

nemcicky_spe <- read.delim ('https://raw.githubusercontent.com/zdealveindy/anadat-r/master/data/nemcicky_spe.txt', row.names = 1)
nemcicky_env <- read.delim ('https://raw.githubusercontent.com/zdealveindy/anadat-r/master/data/nemcicky_env.txt')
nemcicky_ell <- read.delim ('https://raw.githubusercontent.com/zdealveindy/anadat-r/master/data/nemcicky_ell.txt', row.names = 1)
 

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