Fig 1.
Seedling mortality per tree species observed in October 2010 at Beijing and Fuyang.
Bars correspond to the mean mortality (± standard error) recorded per block of 25 seedlings. Bars from the same plot headed by the same letter (Beijing in italics, Fuyang in plain) are not significantly different (Kruskall-Wallis test followed by all-pairwise comparisons of mean ranks at α = 0.05). Carpinus betulus, Fagus sylvatica and Quercus petraea were not planted at the Beijing site. The Beijing plot was planted in 2007 and the Fuyang plot in 2008.
Fig 2.
Foliage damage and damage morphotypes observed by late October 2010 at Beijing and Fuyang.
A: total damage (± standard error; bars headed by the same letter are not significantly different; Kruskall-Wallis test followed by all-pairwise comparisons of mean ranks at α = 0.05); B: relative importance of morphotype damage at Beijing; C: relative importance of morphotype damage at Fuyang. In B and C, several morphotypes can be observed on the same leaf, and summation of the morphotype damage could be higher than total damage. See text for the definition of the morphotypes. The Beijing plot was planted in 2007 and the Fuyang plot in 2008.
Fig 3.
Numeric importance per family of the insect species that colonized the sentinel trees in China from 2007 to 2011.
Species with more than 5 occurrences were observed on more than 5 seedlings during at least two different years. The Beijing plot was planted in 2007 and the Fuyang plot in 2008.
Fig 4.
Annual changes in the cumulative number of insect species recruited by European sentinel trees planted in Beijing and Fuyang from 2007 to 2011.
The Beijing plot was planted in 2007 and the Fuyang plot in 2008.
Fig 5.
Comparative colonization of the different species of European trees planted at two sites in China and the frequency of the colonization events.
No. spp > 5 events means that these insect species were observed on more than 5 seedlings during two different years (pooled over both sites). Note that an individual insect species can be observed on more than a single tree species.
Table 1.
Insect species that colonized the European sentinel trees planted in Fuyang and Beijing more than 5 times between 2007 and 2011.