Reduced stem growth, but no reserve depletion or hydraulic impairment in beech suffering from long-term decline
Under non-extreme drought conditions, reduced stem growth is not associated with reserve or hydraulic impairment in beech suffering from long-term decline.
Global change is expected to increase the frequency and the intensity of drought events in temperate ecosystems. In some regions, this might be associated with an increase in tree decline. Of the ecophysiological mechanisms that have been proposed to explain tree decline, an impairment of the vascular transport system and/or carbon function are two of the most discussed. In a context of long-term decline caused by droughts, we investigated the functional differences between the carbon, nitrogen, and hydraulic functions of healthy and declining mature beech (Fagus sylvatica L.) trees. The study was carried out over two consecutive years with contrasting water availabilities. The radial growth of declining trees was clearly less than that of healthy trees, due to a lower growth rate, associated during the wet year with a shorter growth period. Leaf functional characteristics and hydraulic parameters (native embolism and cavitation vulnerability curves) were similar in healthy and declining trees. However, at the end of a growing season characterized by a dry spring, carbon reserves concentrations in young branches of declining trees were lower than those in healthy trees, though they recovered during the following non-constraining growing season. Our results did not indicate carbon starvation, nitrogen deficiency, or hydraulic failure. However, there seems to be some compensation mechanism related to reserve dynamics in the remaining living tissue of the declining trees. This study shows that the climate conditions of successive years are probably crucial for these functional adjustments to be operational.
KeywordsBeech Reserves Forest decline Growth Hydraulic failure
The authors would like to acknowledge the students who contributed to data collection and field work: Alain Sévéré for his help with the branch sampling, and Michèle Viel and Patricia Le Thuaut for technical assistance. We are grateful to the French National Forest Office (ONF) for allowing us to carry out these experiments. The authors thank Stéphane Herbette (UMR PIAF INRA, Université Blaise Pascal), for help with the measurements of vulnerability curves.
Compliance with ethical standards
AD’s doctoral grant was provided by the French Ministry of Higher Education and Scientific Research. Additional financial support was provided by a CYTRIX project (EC2CO) funded by CNRS and INSU and also by the ESE laboratory supported by the University Paris-Sud, CNRS and AgroParisTech.
Conflict of interest
The authors declare that they have no conflict of interest.
- Adams HD, Guardiola-Claramonte M, Barron-Gafford GA et al (2009) Reply to Sala: temperature sensitivity in drought-induced tree mortality hastens the need to further resolve a physiological model of death. Proc Natl Acad Sci USA 106:E69. doi: 10.1073/pnas.0905282106 PubMedCentralCrossRefGoogle Scholar
- Aussenac G, Ducrey M (1977) Etude bioclimatique d’une futaie feuillue (Fagus silvatica L. et Quercus sessiliflora Salisb.) de l’Est de la France. I—Analyse des profils microclimatiques et des caractéristiques anatomiques et morphologiques de l’appareil foliaire. Ann des Sci For 34:265–284CrossRefGoogle Scholar
- Brummer Y, Cui SW (2005) Understanding carbohydrate analysis. Food Carbohydr Chem Phys Prop Appl. Taylor and Francis group, pp 67–104Google Scholar
- Bussotti F, Prancrazi M, Matteucci G, Gerosa G (2005) Leaf morphology and chemistry in Fagus sylvatica (beech) trees as affected by site factors and ozone: results from CONECOFOR permanent monitoring plots in Italy. Tree Physiol 25:211–219. doi: 10.1093/treephys/25.2.211 CrossRefPubMedGoogle Scholar
- Closa I, Irigoyen JJ, Goicoechea N (2010) Microclimatic conditions determined by stem density influence leaf anatomy and leaf physiology of beech (Fagus sylvatica L.) growing within stands that naturally regenerate from clear-cutting. Trees Struct Funct 24:1029–1043. doi: 10.1007/s00468-010-0472-3 CrossRefGoogle Scholar
- Durand-Gillmann M, Cailleret M, Boivin T et al (2012) Individual vulnerability factors of Silver fir (Abies alba Mill.) to parasitism by two contrasting biotic agents: mistletoe (Viscum album L. ssp. abietis) and bark beetles (Coleoptera: Curculionidae: Scolytinae) during a decline process. Ann For Sci 69:1–15. doi: 10.1007/s13595-012-0251-y CrossRefGoogle Scholar
- Fotelli MN, Rennenberg H, Geßler A (2002) Effects of drought on the competitive interference of an early successional species (Rubus fruticosus) on Fagus sylvatica L. Seedlings: 15 N uptake and partitioning, responses of amino acids and other N compounds. Plant Biol 4:311–320. doi: 10.1055/s-2002-32334 CrossRefGoogle Scholar
- Intergovernmental Panel on Climate Change (2014) Climate change 2014: synthesis reportGoogle Scholar
- Keitel C, Matzarakis A, Rennenberg H, Geßler A (2006) Carbon isotopic composition and oxygen isotopic enrichment in phloem and total leaf organic matter of European beech (Fagus sylvatica L.) along a climate gradient. Plant Cell Environ 29:1492–1507. doi: 10.1111/j.1365-3040.2006.01520.x CrossRefPubMedGoogle Scholar
- Lorenz M, Becher G (2012) Forest condition in Europe 2012, technical report of ICP forests, HamburgGoogle Scholar
- Nageleisen LM, Goudet M (2011) Manuel de Notation des dommages forestiers (symptômes, causes, état des cimes), ParisGoogle Scholar
- Silva DE (2010) Ecologie du hêtre (Fagus sylvatica L.) en marge sud-ouest de son aire de distribution. Université Henri Poincaré, NancyGoogle Scholar