Fungi are important drivers of ecosystem function. Pathogens however can impair productivity stability. We are interested in determining whether there is an effect of tree species diversity on regulating foliar fungal pathogens in the Italian forests in Tuscany. We hypothesize that higher diversity mixture plots will have a lower incidence of pathogens and pathogen damage than monoculture plots. Leaf samples from selected target trees were collected between June 18 and July 4, 2012 by tree climbers or with extension loopers. Target tree species include: Castanea sativa, Ostrya carpinifolia, Quercus cerris, Quercus ilex, and Quercus petraea. Leaves from two levels of the canopy were sampled; 25-50 from the sun-exposed upper and 25-50 from the lower part of the canopy. When possible, branches came from the south facing exposition. Damages were assessed based on two categories, powdery mildew and leaf spots.

Two objectives in task 4.6 were achieved with the sampling of fresh leaves from target trees: performing damage assessment (this workbook) and collecting leaves for molecular analysis (not in this workbook, but the leaves were from the same selected trees described below) Leaves were sampled from trees along gradients like diversity. From provided tree size data, the trees sorted based on DBH. The 12 largest trees based on DBH were selected from monoculture plots and 6 trees for the those trees in mixture plots. From these, 6 trees were randomly selected (Excel random number generator) in the monoculture plots and 3 trees were selected from mixture plots. Sometimes the pre-selected tree needed to be changed in the field. Leaves were selected randomly from cut branches; 25-50 leaves from the sun-exposed upper canopy and 25-50 leaves from the lower part of the canopy.

Exploratory Region: Italy

Between June 18, 2012 and July 4, 2012

Leaves from Castanea sativa, Ostrya carpinifolia, Quercus cerris, Quercus ilex, and Quercus petraea

Are there circumstances that explain the precision of your measurements? Could it be that a sandstorm destroyed part of the plots in a given year?

Columns A-D provide the unique identification for each focal tree. Column E indicates the branch from which the leaves were sampled for that particular focal tree. Columns F-H indicate the number of leaves with powdery mildew (mildew), the number of leaves without powdery mildew (m.healthy), and the total number of leaves assessed for powdery mildew (m.total), respectively. Columns I-K indicate the number of leaves with leaf spots (spots), the number of leaves without leaf spots (s.healthy), and the total number of leaves assessed for leaf spots (s.total), which are the same leaves assessed for powdery mildew, respectively. Columns L and M indicate the number of shoots with rust (rust.current) and needle cast (cast.current), respectively for the current year needles (i.e. from 2012). Columns N and O indicate the number of healthy shoots (healthy.current) and total number of shoots sampled (ndl.tot.current) for that cohort of shoots, respectively. Columns P-S have the same notes the same as columns L-O, except for data from the previous year needle cohorts (indicated with ".prev") (i.e. from 2011). Column T indicates the overall number of healthy leaves or healthy current year shoots. Column U indicates the total number of leaves or current year shoots sampled.