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 Satakunta, Finland. We hypothesize that higher diversity mixture plots will have a lower incidence of pathogens and pathogen damage than monoculture plots. Leaf and needle samples from selected target trees were collected between August 12 and August 15, 2011 with extension loopers. Target tree species include: Betula pendula, Picea abies, Pinus sylvestris, Alnus glutinosa and Larix siberica. Leaves from two levels of the canopy were sampled; 25 from the upper and 25 from the lower part of the canopy for the north facing and south facing expositions (4 branches in total per tree). For conifers, unspecified number of shoots were sampled for each of the first two years' cohorts for the upper branch and similarly for the lower branch for the north facing and south facing expositions (4 branches per tree, 8 cohorts in total). Damages were assessed based on two categories, powdery mildew and leaf spots for the broadleaved trees and two categories for the conifers, rust and needle cast. Additionally, the number of observed leaf and branch deformations, shoot diebacks and cankers were noted for the cut portions of branches.

Two objectives in task 4.6 were achieved with the sampling of fresh leaves and needles from target trees: performing damage assessment (this workbook) and collecting leaves and needles (from the 2010 and 2011, previous and current year cohorts only) for molecular analysis (not in this workbook, but the leaves and needles were from the same selected trees described below) Leaves and needles were sampled from trees along a tree species diversity gradient. Five trees per species were pre-selected. Leaves from broadleaved trees were selected randomly from cut branches; 25 leaves from the upper canopy and 25 leaves from the lower part of the canopy, where possible, for each of the north and south facing expositions. For molecular analysis, needles from conifers were selected randomly from cut branches with 5 shoots from the current year cohort and 5 shoots from the previous year cohort from the upper canopy, and the same scheme for the lower part of the canopy for each of the north and south facing expositions. For damage assessment of needles from conifers, a visual approximation of percentage classes were noted from the available shoots.

Plantation: Satakunta, Finland

Between August 12, 2011 and August 15, 2011

Leaves from Betula pendula and Alnus glutinosa, and needles from Picea abies, Pinus sylvestris and Larix siberica

Columns A-F are explanatory variables with Column F indicating the year to which the foliage assessed appeared. Column E indicates the branch for which the data is relevant. TN = top branch, north exposition, TS = top branch, south exposition, BN = bottom branch, north exposition, and BS = bottom branch, south exposition. Columns G-P are the response variables. The values in columns G-J indicate the number of leaves with powdery mildew or leaf spots or those leaves that are healthy. Column J indicates the total number of leaves assessed. Columns K and L indicate the percentage of shoots with rust and needle cast, respectively for the noted needle cohort. Data for rust and needle cast are collected such that what is reflected is a percentage of shoots with damage based on visual averages (as opposed to out of a fixed number of shoots). There were percentage classes that were marked for these symptoms: 0, 1-5, 6-10, 11-25, 26-50, 51-75, and >76. The numbers reflected are the midpoints of each class. Columns M indicates the number of leaves with deformations, column N indicates the number of cankers, column O indicates the number of shoots with dieback, and column P indicates the number of shoots with deformations for the respective branch of the respective tree.