Radial growth resilience of sessile oak after drought is affected by site water status, stand density, and social status

Trees ◽  
2016 ◽  
Vol 31 (2) ◽  
pp. 517-529 ◽  
Author(s):  
Raphaël Trouvé ◽  
Jean-Daniel Bontemps ◽  
Catherine Collet ◽  
Ingrid Seynave ◽  
François Lebourgeois
Keyword(s):  
Social Status ◽  
Radial Growth ◽  
Water Status ◽  
Stand Density ◽  
Sessile Oak ◽  
Site Water

scholarly journals Implications of Reduced Stand Density on Tree Growth and Drought Susceptibility: A Study of Three Species under Varying Climate

Forests ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 627
Author(s):  
Mathias Steckel ◽  
W. Keith Moser ◽  
Miren del Río ◽  
Hans Pretzsch
Keyword(s):  
Scots Pine ◽  
Tree Growth ◽  
Water Availability ◽  
Ponderosa Pine ◽  
Stand Density ◽  
Stand Age ◽  
Short Term ◽  
Sessile Oak ◽  
Site Water ◽  
Positive Effect

A higher frequency of increasingly severe droughts highlights the need for short-term measures to adapt existing forests to climate change. The maintenance of reduced stand densities has been proposed as a promising silvicultural tool for mitigating drought stress. However, the relationship between stand density and tree drought susceptibility remains poorly understood, especially across ecological gradients. Here, we analysed the effect of reduced stand density on tree growth and growth sensitivity, as well as on short-term drought responses (resistance, recovery, and resilience) of Scots pine (Pinus sylvestris L.), sessile oak (Quercus petraea (Matt.) Liebl.), and ponderosa pine (Pinus ponderosa Douglas ex C. Lawson). Tree ring series from 409 trees, growing in stands of varying stand density, were analysed at sites with different water availability. For all species, mean tree growth was significantly higher under low compared with maximum stand density. Mean tree growth sensitivity of Scots pine was significantly higher under low compared with moderate and maximum stand density, while growth sensitivity of ponderosa pine peaked under maximum stand density. Recovery and resilience of Scots pine, as well as recovery of sessile oak and ponderosa pine, decreased with increasing stand density. In contrast, resistance and resilience of ponderosa pine significantly increased with increasing stand density. Higher site water availability was associated with significantly reduced drought response indices of Scots pine and sessile oak in general, except for resistance of oak. In ponderosa pine, higher site water availability significantly lessened recovery. Higher site water availability significantly moderated the positive effect of reduced stand density on drought responses. Stand age had a significantly positive effect on the resistance of Scots pine and a negative effect on recovery of sessile oak. We discuss potential causes for the observed response patterns, derive implications for adaptive forest management, and make recommendations for further research in this field.

Growth of lesions of Phytophthoracinnamomi in stems and roots of jarrah (Eucalyptusmarginata) in relation to rainfall and stand density in mediterranean forest of Western Australia

1995 ◽  
Vol 25 (6) ◽  
pp. 961-969 ◽  
Author(s):  
F.J. Bunny ◽  
D.S. Crombie ◽  
M.R. Williams
Keyword(s):  
Water Status ◽  
Stand Density ◽  
Summer Rainfall ◽  
Relative Difference ◽  
Jarrah Forest ◽  
Water Deficits ◽  
Small Water ◽  
Water Potentials ◽  
Site Water ◽  
Lesion Extension

The effects of reduced stand density on (i) water status of jarrah (Eucalyptusmarginata Donn ex Sm.) and (ii) growth rate of artificially induced lesions of Phytophthoracinnamomi Rands in phloem of E. marginata were examined. Plots in the high ( > 1100 mm•year−1), intermediate (900–1100 mm•year−1), and low ( < 900 mm•year−1) rainfall zones of the jarrah forest were thinned to controlled fractions of original stand density. Phytophthoracinnamomi lesions in the phloem of stems and roots were established by wound inoculation. Lesions of P. cinnamomi were longer in stems of trees with small water deficits than in trees with larger water deficits. For example, in 1991 at the intermediate rainfall site, water potentials and lesion lengths of trees on unthinned and thinned plots were −1.1 and −0.9 MPa and 23 and 45 cm, respectively. Lesions grew more slowly in roots than in stems (average 10.0 and 26.2 cm, respectively, after 55 days at unthinned high rainfall site in 1991); however, the relative difference between lesions in trees with the highest and lowest water potentials was greater in roots (up to 2.7 times) than in stems. Lesion extension was also affected by summer rainfall, with longer lesions occurring in summers of highest rainfall. Viability of P. cinnamomi in 10-week-old and 1-year-old lesions decreased as tree water deficits increased. Differences in lesion extension between jarrah in different amounts of summer rainfall were largely explained by differences in dawn water potential.

scholarly journals Drought or Severe Drought? Hemiparasitic Yellow Mistletoe (Loranthus europaeus) Amplifies Drought Stress in Sessile Oak Trees (Quercus petraea) by Altering Water Status and Physiological Responses

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2985
Author(s):  
Martin Kubov ◽  
Peter Fleischer ◽  
Jozef Rozkošný ◽  
Daniel Kurjak ◽  
Alena Konôpková ◽  
...  
Keyword(s):  
Water Status ◽  
Leaf Size ◽  
Quercus Petraea ◽  
Severe Drought ◽  
Sessile Oak ◽  
Leaf Transpiration ◽  
Oak Trees ◽  
Psii Photochemistry ◽  
Use Efficiency ◽  
Stem Increment

European oak species have long been considered relatively resistant to different disturbances, including drought. However, several recent studies have reported their decline initiated by complex changes. Therefore, we compared mature sessile oak trees (Quercus petraea (Matt.), Liebl.) infested versus non-infested by hemiparasitic yellow mistletoe (Loranthus europaeus Jacq.) during the relatively dry vegetation season of 2019. We used broad arrays of ecophysiological (maximal assimilation rate Asat, chlorophyll a fluorescence, stomatal conductance gS, leaf morphological traits, mineral nutrition), growth (tree diameter, height, stem increment), and water status indicators (leaf water potential Ψ, leaf transpiration T, water-use efficiency WUE) to identify processes underlying vast oak decline. The presence of mistletoe significantly reduced the Ψ by 1 MPa, and the WUE by 14%. The T and gS of infested oaks were lower by 34% and 38%, respectively, compared to the non-infested oaks, whereas the Asat dropped to 55%. Less pronounced but significant changes were also observed at the level of photosystem II (PSII) photochemistry. Moreover, we identified the differences in C content, which probably reduced stem increment and leaf size of the infested trees. Generally, we can conclude that mistletoe could be a serious threat that jeopardizes the water status and growth of oak stands.

Tree-ring model interprets growth decline in natural stands of loblolly pine in the southeastern United States

1989 ◽  
Vol 19 (5) ◽  
pp. 612-621 ◽  
Author(s):  
Robert Zahner ◽  
Joseph R. Saucier ◽  
Richard K. Myers
Keyword(s):  
Tree Ring ◽  
Loblolly Pine ◽  
Radial Growth ◽  
Ring Width ◽  
Stand Density ◽  
Climatic Conditions ◽  
Radial Increment ◽  
Aggregate Model ◽  
Ring Model ◽  
Pine Stands

Annual ring widths and ring areas from 131 even-aged, natural, well-stocked stands of loblolly pine (Pinustaeda L.) in the Piedmont region were analyzed to reveal possible causes of a previously reported decline in radial growth. A linear aggregate model was used to separate independent factors that are known to contribute to radial growth variation in this species. Stand, site, and climatic conditions were reconstructed for each stand for the 36-year period 1949–1984 from previous inventories and from weather records at appropriately located stations. Within each of six 5-year age-classes, the model identified declines in both ring width and ring area associated with stand density, climate changes, and the passage of time. Regional climate first ameliorated this decline as pine stands passed from droughty conditions early in the 36-year period to a favorable climate during the middle of the period, and the decline accelerated later with the return of dry conditions toward the end of the period. The tree-ring model simulates a decline in radial increment in trees in natural pine stands between the ages of 20 and 45 years in the Piedmont which has averaged 1% per year since 1950. Part of the downward trend was attributed to increased competition, part to regional drought, and a considerable part to unidentified factors, possibly regional atmospheric deposition.

Changes in root morphology after precommercial thinning in balsam fir stands

2003 ◽  
Vol 33 (12) ◽  
pp. 2452-2459 ◽  
Author(s):  
Jean-Claude Ruel ◽  
Catherine Larouche ◽  
Alexis Achim
Keyword(s):  
Radial Growth ◽  
Abies Balsamea ◽  
Stand Density ◽  
Balsam Fir ◽  
Cross Sectional ◽  
Beam Shape ◽  
Precommercial Thinning ◽  
Beneficial Effects ◽  
Density Control ◽  
Over Time

Precommercial thinning is often used to control stand density in naturally regenerated balsam fir (Abies balsamea (L.) Mill.) stands. Early stand density control could have beneficial effects on longer term stand stability through a modification of stem shape and root development. To assess the effect of precommercial thinning, two thinned and two unthinned stands were selected. Root sections were collected at 25 cm from the centre of the stem for all major roots (diameter greater than 2 cm). A disk was also cut at breast height level. From these disks, response in radial growth was determined. Detailed root measurements were taken on the sample disks to assess treatment effect on the following variables: asymmetry in root cross-sectional area (CSA) distribution, individual root shape, as well as changes in root shape over time. A quick and pronounced response in root growth occurred. This response was greater than that observed in the trunk. No asymmetry in root CSA distribution was observed at the stand level. Trees allocated more to radial growth above the biological centre of the root both in treated and control stands, but this trend was increased by thinning. Roots also tended to develop T-beam shapes over time, both in control and thinned stands. Most roots initially did not possess an I-beam shape and did not develop one during the course of the study. According to our results, trees respond quickly to the new growing conditions created by thinning by increasing biomass allocation to parts of the roots where mechanical stresses are greater.

Dépérissement, déficit hydrique et variations de croissance radiale chez le Picea abies

1990 ◽  
Vol 68 (7) ◽  
pp. 1536-1541 ◽  
Author(s):  
P. M. Badot ◽  
P. Perrier ◽  
M. J. Badot
Keyword(s):  
Water Content ◽  
Radial Growth ◽  
Forest Decline ◽  
Water Status ◽  
Ring Width ◽  
Growth Index ◽  
Diameter Growth ◽  
Past Century ◽  
Severe Drought ◽  
French Jura

Changes in the water status of spruce needles have been studied in relation with the present dieback disease of forests in the French Jura. A study of the variation in width of annual rings has been conducted to evaluate if radial growth was disturbed during forest decline. The water content of the needles displayed great individual variability, but at the population level, variation in water content was closely correlated to the health status of the trees: at the same age, the needles of the damaged trees showed lower water content than those of the healthy ones. A mean diameter growth index was used to take into account the effect of ageing of the trees on diameter growth. Globally, this index increased during the past century: such a result indicates that the vigour of the spruce populations had not been altered since the beginning of the century. The healthy and diseased trees displayed the same variation in the mean growth index until 1949. Then, the affected spruces had annual increments lower than those of the healthy trees during two periods, from 1949 to 1959 and from 1973 to 1987. These growth crises correspond to periods with a pronounced rainfall deficit, which often included one or several years of severe drought. Thus, poor water supply could play a role in the present decline of spruce in the French Jura. Key words: radial growth, forest decline, tree-ring width, drought, water content.

scholarly journals Stand density, tree social status and water stress influence allocation in height and diameter growth ofQuercus petraea(Liebl.)

2015 ◽  
Vol 35 (10) ◽  
pp. 1035-1046 ◽  
Author(s):  
Raphaël Trouvé ◽  
Jean-Daniel Bontemps ◽  
Ingrid Seynave ◽  
Catherine Collet ◽  
François Lebourgeois
Keyword(s):  
Water Stress ◽  
Social Status ◽  
Stand Density ◽  
Diameter Growth ◽  
Stress Influence
Sign in / Sign up

Export Citation Format

Share Document