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Growth reduction after defoliation is independent of CO 2 supply in deciduous and evergreen young oaks
Author(s) -
Schmid Sandra,
Palacio Sara,
Hoch Günter
Publication year - 2017
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.14484
Subject(s) - evergreen , deciduous , quercus petraea , fagaceae , growing season , biology , botany , allometry , specific leaf area , agronomy , photosynthesis , ecology
Summary Reduced productivity of trees after defoliation might be caused by limited carbon (C) availability. We investigated the combined effect of different atmospheric CO 2 concentrations (160, 280 and 560 ppm) and early season defoliation on the growth and C reserves (nonstructural carbohydrates ( NSC )) of saplings of two oak species with different leaf habits (deciduous Quercus petraea and evergreen Quercus ilex ). In both species, higher CO 2 supply significantly enhanced growth. Defoliation had a strong negative impact on growth (stronger for Q. ilex ), but the relative reduction of growth caused by defoliation within each CO 2 treatment was very similar across all three CO 2 concentrations. Low CO 2 and defoliation led to decreased NSC tissue concentrations mainly in the middle of the growing season in Q. ilex , but not in Q. petraea . However, also in Q. ilex , NSC increased in woody tissues in defoliated and low‐ CO 2 saplings towards the end of the growing season. Although the saplings were C limited under these specific experimental conditions, growth reduction after defoliation was not directly caused by C limitation. Rather, growth of trees followed a strong allometric relationship between total leaf area and conductive woody tissue, which did not change across species, CO 2 concentrations and defoliation treatments.