Data on the population density of tree pipits, Anthus trivialis, in
Franconian oak forests including variables describing the forest ecosystem.
Usage
treepipit
Format
A data frame with 86 observations on 10 variables.
counts
the number of tree pipits observed.
age
age of the overstorey oaks taken from forest data.
coverstorey
cover of canopy overstorey (%). The crown cover is described relative to
a fully stocked stand. Very dense overstorey with multiple crown cover
could reach values greater than 100 %.
coverregen
cover of regeneration and shrubs (%).
meanregen
mean height of regeneration and shrubs.
coniferous
coniferous trees (% per hectare).
deadtree
number of dead trees (per hectare).
cbpiles
number of crowns and branch piles (per hectare). All laying crowns and
branch piles were counted. These were induced by logging and the creation
of wind breaks.
ivytree
number of ivied trees (per hectare).
fdist
distance to the forest edge. The closest distance to the forest edge was
measured from the centre of each grid.
Details
This study is based on fieldwork conducted in three lowland oak forests in the
Franconian region of northern Bavaria close to Uffenheim, Germany. Diurnal
breeding birds were sampled five times, from March to June 2002, using a
quantitative grid mapping. Each grid was a one-hectare square. In total, 86
sample sites were established in 9 stands. All individuals were counted in
time intervals of 7 min/grid during slow walks along the middle of the grid
with a stop in the centre. Environmental factors were measured for each
grid.
References
Müller, J. and Hothorn, T. (2004). Maximally selected
two-sample statistics as a new tool for the identification and assessment of
habitat factors with an application to breeding bird communities in oak
forests. European Journal of Forest Research123(3), 219–228.