Synergistic effects of pathogen infection and climate stress on growth of European chestnut (Castanea sativa Mill.)

Synergistic effects of pathogen infection and climate stress on growth of European chestnut (Castanea sativa Mill.)

The pathogenic chestnut blight fungus (Cryphonectria parasitica (Murill) Barr) has threatened European chestnut stands (Castanea sativa Mill.) in the 20th century. Because C. parasitica affects radial stem growth by interfering with the movement of water, we applied dendroecological methods to retrospectively analyse synergistic effects of blight infection and climate stress on growth decline of C. sativa. The study area was located within a dry inner Alpine valley south of the Central Eastern Alps (Eisack-valley, Italy), where first signs of blight infection were observed in the early 1970s. Growth-climate relationships using response function analysis and Pearson correlation coefficients revealed that irrespective of the intensity of crown dieback C. sativa growth is strongly affected by low precipitation from December to February. Future studies will therefore focus on a more detailed interpretation of the relationship between radial stem growth and drought by determination of intra-annual dynamics of wood formation in relation to tree phenology, climate and site conditions. Furthermore, it is intended to establish well replicated ring width chronologies of C. sativa at drought-prone sites to be able to develop a dendroclimatic model, which can be used to reconstruct rainfall variability south of the Central Alps for the last c. 300 years.

Publications
Waldboth M., W. Oberhuber (2009) Synergistic effect of drought and chestnut blight (Cryphonectria parasitica) on growth decline of European chestnut (Castanea sativa). Forest Pathology 39:43-55
 

 Personnel involved
Mirjam Waldboth
Walter Oberhuber