We studied two groups of trees – survivors and dead oaks. Oaks that died had higher BAI than trees that survived until the drainage event, after which BAI of trees that died declined dramatically. Hydraulic diameter and conductivity of vessels in trees that died was higher than in surviving trees until the last five years prior to mortality, at which time both groups had similar values. Trees that died had consistently lower D than trees that survived. We propose that trees that died may have been hydraulically underbuilt for dry conditions, which predisposes them to subsequent mortality.
COBISS.SI-ID: 3118246
We compiled a dendrochronological network of more than 5000 tree-ring series from 70 larch host and 73 spruce nonhost sites within the European Alps and Tatra Mountains. We developed annual maps of reconstructed defoliation showing historical persistence of cyclic outbreaks at the site level, recurring c. every 8–9 yr. Our study demonstrates the persistence of recurring insect outbreaks during ad 1700–2000 and emphasizes that a widely distributed tree-ring network and novel analysis methods can contribute towards an understanding of the changes in insect outbreaks and climate dependence.
COBISS.SI-ID: 2396582
Ring width, maximum latewood density, annual height increment and latewood cellulose carbon isotope composition were determined at both sites and the resulting time-series compared with and verified against instrumental climate data for their common period (AD1960-AD2002). Results indicate that ring width sensitivity to summer temperature is very site-dependent, with opposing responses at alpine and lowland sites. Stable carbon isotopes have most potential, responding strongly to summer temperature in both alpine and lowland stands.
COBISS.SI-ID: 2249894
We studied the timing of xylem and phloem formation, and the widths and structure of completed xylem and phloem increments in sessile oak (Quercus sessiliflora Salisb.). Phloem production was faster in the first part of the growing season, but thereafter xylem production accelerated. The period of most intense xylem cell production was period April-May and that of phloem in April. Production of cells in the cambium stopped in the first half of August on xylem and phloem sides. The portion of late wood increased with the width of the xylem growth rings.
COBISS.SI-ID: 3102886
Pressure volume curves were applied to define differences in stress adaptation between diff. forest sites. Species response between adult stands after stronger thinning and comparable stand without any silvicultural measures within same forest complex was compared in 2003 and 2004. Significant differences in osmotic potential component in Murska šuma in 2003 and Krakovo forest between managed forest and old growth-forest were confirmed. In all cases, values became more negative, indicating capability of oaks to adapt with increasing drought stress.
COBISS.SI-ID: 3026854