Habitat lo
ss i
s one of the major driver
s of the reduction in biological diver
sity worldwide. European dry gra
ssland
s are particularly endangered. However, the per
si
stence of population
s can temporarily mitigate
specie
s lo
ss - a proce
ss referred to a
s 鈥榚xtinction debt鈥? We te
st thi
s hypothe
si
s u
sing hi
storical and pre
sent day habitat map
s and current plant biodiver
sity data collected in the fore
st-
steppe zone of Europe. In 16 5 km 脳 5 km
study
site
s, repre
senting the land
scape heterogeneity of the Ki
skun
s谩g region (Hungary), 86 20 m 脳 20 m vegetation plot
s were
surveyed in open and clo
sed calcareou
s sand gra
ssland
s. Gra
ssland diver
sity wa
s mea
sured a
s the number of
speciali
st
specie
s, defined by
stati
stical fidelity mea
sure
s u
sing primary and
secondary gra
ssland plot
s. Land
scape context wa
s quantified u
sing the areal extent of
semi-natural fore
st-
steppe vegetation in a 300 m neighborhood of the plot
s, ba
sed on recent and hi
storical map
s (1783, 1860, 1950
s, 1987-1989 and 2005). The number of
speciali
st
specie
s wa
s e
stimated with Poi
sson generalized linear model
s u
sing the pre
sent land
scape context, climatic condition
s, and a proxy of
soil type a
s covariate
s. To te
st for the effect of hi
storical legacie
s, Pear
son re
sidual
s from the pre
sent model
s were te
sted for
significant relation
ship
s between the re
sidual
s and the hi
storical land
scape context
s u
sing linear model
s.
We found that the present landscape context had no significant relationship with the specialist species richness of the primary grassland fragments. However, we found a significant relationship between the historical landscape context of the 19th century and the residuals of the present model. Even though the extent of natural vegetation in the 20th century showed more drastic changes, the landscape context in 1950s and 1987-1989 exhibited no significant statistical relationship with the residuals. This delay of species loss is consistent with the extinction debt hypothesis.