Effects of irrigation on diameter growth and vertical resin duct production in Pinus sylvestris L. on dry sites in the central Alps, Switzerland

Response of <i>Pinus sylvestris</i> roots to sheet-erosion exposure: an anatomical approach

“…Therefore, resin ducts located around the whole root circumference form barrier zones in the secondary xylem. Resin duct occurrence in Pinus sylvestris has been reported to be a valuable dendroecological variable (Rigling et al, 2003) but at the same time, some authors do not consider it as suitable for the dating of geomorphic processes (see Stoffel, 2008). In our case study, although resin duct production seems to be positively linked to radial growth, it does not always occur at the same time of exposure (see Fig.…”

Tree-Ring Reconstruction of Debris-Flow Events Leading to Overbank Sedimentation on the Illgraben Cone (Valais Alps, Switzerland)

“…We therefore analyzed precipitation records of the last 143 years (1864-2007) from nearby weather stations (i.e. Sion and Sierre, located 5 and 21 km west of the study site, respectively) of the Swiss Meteorological Institute [26] and results from dendroecological studies [23,24,36] in order to exclude the influence of water stress and related droughts on the dendrogeomorphological reconstruction. In two cases and due to the fact that GD did not only occur in the form of abrupt growth suppression but also as injuries and compression wood, debris-flow events were dated although the years in question were known for their droughts.…”

“…Single steps of sample analysis included surface preparation, counting of tree rings, skeleton plots as well as ring-width measurements using digital LINTAB positioning tables connected to a Leica stereomicroscope and TSAP 3.0 (Time Series Analysis and Presentation) software [35]. Growth curves of the disturbed samples were then compared with precipitation records from the Swiss Meteorological Institute [26] and results from dendroecological studies [23,24,36] to separate climatically driven fluctuations (e.g., droughts, frost) in tree growth from GD caused by debris flows [37].…”

“…gneiss or granite), they have, at the same time, completely disregarded (i) the investigation of activity in regions dominated by finely fractured calcareous and dolomitic lithologies or (ii) the analysis of exceptional debris-flow events in canyons leading to overbank sedimentation on cones. In a similar way and due to their sensitivity towards drought stress [23,24], (iii) tree-ring series of Scots pine (Pinus sylvestris L.) have only very rarely been used for dendrogeomorphological investigations in Switzerland so far.…”

The enhancement of cultural landscapes in mountain environments: An artificial channel history (Torrent-Neuf, Canton Valais, Switzerland) and the role of trees as natural archives of water flow changes

“…The analyzed PaK confirm anyway a sensitivity to rainfall regime by well recording the drought years. According to Rigling et al (2003) man-induced hydrological change may mitigate or exasperate the negative effect of natural hydrological change on trees. Even if the water diversion along the TN did not heavily affected trees growth neither when the TN was closed nor when water started to flow again, the TN chronologies show: 1) how depletion in water availability may influence and slow down the recovery of a »normal growth« after drought years; 2) drought years less affect tree growth when the TN is active.…”