Elevated atmospheric CO2 and humidity delay leaf fall in Betula pendula, but not in Alnus glutinosa or Populus tremula × tremuloides
- 345 Downloads
Anthropogenic activity has increased the level of atmospheric CO2, which is driving an increase of global temperatures and associated changes in precipitation patterns. At Northern latitudes, one of the likely consequences of global warming is increased precipitation and air humidity.
In this work, the effects of both elevated atmospheric CO2 and increased air humidity on trees commonly growing in northern European forests were assessed.
The work was carried out under field conditions by using Free Air Carbon dioxide Enrichment (FACE) and Free Air Humidity Manipulation (FAHM) systems. Leaf litter fall was measured over 4 years (FACE) or 5 years (FAHM) to determine the effects of FACE and FAHM on leaf phenology.
Increasing air humidity delayed leaf litter fall in Betula pendula, but not in Populus tremula × tremuloides. Similarly, under elevated atmospheric CO2, leaf litter fall was delayed in B. pendula, but not in Alnus glutinosa. Increased CO2 appeared to interact with periods of low precipitation in summer and high ozone levels during these periods to effect leaf fall.
This work shows that increased CO2 and humidity delay leaf fall, but this effect is species-specific.
KeywordsClimate change Free air CO2 enrichment (FACE) Free air humidity manipulation Leaf fall Ozone
The FAHM study was supported by the Ministry of Education and Science of Estonia (grant SF SF0180025s12) and by the EU through the European Social Fund (Mobilitas postdoctoral grant MJD 257) and the European Regional Development Fund (Centre of Excellence ENVIRON) and Project no. 3.2.0802.11-0043 (BioAtmos). The development of BangorFACE site infrastructure was funded by SRIF. We thank the Aberystwyth and Bangor Universities Partnership Centre for Integrated Research in the Rural Environment and the Forestry Commission Wales for financially supporting the running costs of the experiment. Andrew Smith was supported by the Sir Williams Roberts PhD Scholarship match funded by the Drapers’ Company.
- Ahmed IUMT (2006) Leaf decomposition of birch (Betula pendula), alder (Alnus glutinosa) and beech (Fagus sylvatica) grown under elevated atmospheric CO2. Dissertation, Bangor UniversityGoogle Scholar
- Houpis JLJ, Surano KA, Cowles S, Shinn JH (1988) Chlorophyll and carotenoid concentrations in two varieties of pine ponderosa seedlings subjected to long-term elevated carbon dioxide. Tree Physiol, 4:187–193Google Scholar
- IPCC (2013) Climate change 2013: the physical science basis. Cambridge University Press, CambridgeGoogle Scholar
- Menzel A, Sparks TH, Estrella N, Koch E, Aasa A, Ahas R, Alm-Kubler K, Bissolli P, Brasklavska O, Briede A, Chmielewski FM, Crepinsek Z, Curnel Y, Dahl A, Defila C, Donnelly A, Filella Y, Jatczak K, Mage F, Mestre A, Nordli O, Penuelas J, Pirinen P, Remisova V, Scheifinger H, Striz M, Susnik A, van Vliet AJH, Wielgolaski F-M, Zach S, Zust A (2006) European phenological response to climate change matches the warming pattern. Glob Chang Biol 12:1–8CrossRefGoogle Scholar
- R Core Team (2014) R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. http://www.R-project.org. Accessed 19 Mar 2014
- Wood S (2014) The mgcv Package v. 1.3-28, Mixed GAM Computation Vehicle with GCV/AIC/REML smoothness estimation. http://cran.rproject.org/web/packages/mgcv/mgcv.pdf. Accessed 19 Mar 2014
- Zuur AF, Leno EN, Walker NJ, Saveliev AA, Smith GM (2009) Mixed effects models and extensions in ecology with R. Springer Verlag, New York, LLC, p 574Google Scholar
- Zuur AF, Leno EN, Smith, GM (2007) Analysing Ecological Data. Springer, New York, p 680Google Scholar