treepipit {coin} | R Documentation |
Data on the population density of tree pipits in Franconian oak forests including variables describing the forest ecosystem.
data("treepipit")
A data frame with 86 observations describing 86 stands with the following 10 variables:
the number of tree pipits observed.
the ages of the overstorey oaks taken from forest data.
percentage of 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 percent.
percentage of cover of regeneration and shrubs.
mean height of regeneration and shrubs.
percentage of coniferous trees.
number of dead trees per grid.
number of crowns and branch piles. All laying crowns and branch piles per hectare were counted. These were induced by logging and the creation of wind breaks.
number of ivied trees. All ivied trees were counted per hectare.
distance to the forest edge. The closest distance to the forest edge was measured from the centre of each grid.
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 samples from March to June 2002 five times, using a quantitative grid mapping. Each grid was a 1-ha square. In total, 86 sample sites weres established. 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.
J\"org M\"uller \& Torsten Hothorn (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 Research 123, 219–228.
maxstat_test(counts ~ age + coverstorey + coverregen + meanregen + coniferous + deadtree + cbpiles + ivytree, data = treepipit)