Consequences of elevated CO2 and O3 on birch canopy structure: Implementation of a canopy growth model

Kull, Olevi; Tulva, Ingmar; Vapaavuori, Elina

doi:10.1016/j.foreco.2005.02.060

Cited by 4 publications

(2 citation statements)

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“…This discrepancy arose from sampling manner for anatomical analysis of wood: to minimise small‐scale spatial variation, the branches were sampled to avoid nodes/branch junctions, that is regions with low xylem conductivity (Schulte and Brooks 2003, Tyree and Zimmermann 2002). The smaller K B in the lower crown is primarily attributable to the predominant development of secondary axes containing short internodes as the proportion long vs short shoots in B. pendula is determined by light availability (Kull et al 2005).…”

Section: Discussionmentioning

confidence: 99%

Effects of light intensity and duration on leaf hydraulic conductance and distribution of resistance in shoots of silver birch (Betula pendula)

Sellin

Õunapuu

Kupper

2008

Physiologia Plantarum

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Variation in leaf hydraulic conductance (K(L)) and distribution of resistance in response to light intensity and duration were examined in shoots of silver birch (Betula pendula Roth). K(L) was determined on detached shoots using the evaporative flux method (transpiration was measured with a porometer and water potential drop with a pressure chamber). Although K(L) depended on light duration per se, its dynamics was largely determined by leaf temperature (T(L)). Both upper-crown leaves and branches developed in well-illuminated environment exhibited higher hydraulic efficiency compared with the lower crown, accounting for vertical trends of apparent soil-to-leaf hydraulic conductance in canopy of silver birch revealed in our previous studies. K(L) varied significantly with light intensity, the highest values for both shade and sun foliage were recorded at photosynthetic photon flux density of 330 micromol m(-2) s(-1). Light responses of K(L) were associated evidently with an irradiance-mediated effect on extravascular tissues involving regulation of cell membrane aquaporins. Effects of irradiance on K(L) resulted in changes of Psi(L), bringing about considerable alteration in partitioning of the resistance between leaves and branch (leafless shoot stem): the contribution of leaves to the shoot total resistance decreased from 94% at -1.0 MPa to 75% at -0.2 MPa. Treatment with HgCl2 decreased hydraulic conductance of both leaves and branches, implying that condition of bordered pit membranes or shoot living tissues may be involved in responses of xylem conductance to Hg2+.

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Section: Discussionmentioning

confidence: 99%

Effects of light intensity and duration on leaf hydraulic conductance and distribution of resistance in shoots of silver birch (Betula pendula)

Sellin

Õunapuu

Kupper

2008

Physiologia Plantarum

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“…Negative impacts of drought on deciduous forests are also likely (Broadmeadow et al, 2005). Water stress in the south may be partially compensated by increased water-use efficiency (Magnani et al, 2004), elevated CO 2 (Wittig et al, 2005) and increased leaf area index (Kull et al, 2005), although this is currently under debate (Medlyn et al, 2001;Ciais et al, 2004).…”

Section: Forestsmentioning

confidence: 99%

A klímaváltozás emberi jogi aspektusai

Kondorosi¹

2013

JEL-KÉP

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Olevi Kull's lifetime contribution to ecology

2008

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In this article dedicated to Olevi Kull (June 22, 1955-January 31, 2007), we draw on his writings (in English and translated) to outline his thoughts on the relationship between scientists and science. We provide a brief synthesis of his most important work, give a short account of his career and, to bring the man into focus, share some personal stories of interactions with him. Kull considered that for a personal understanding to become scientific knowledge it must be explained convincingly based on theory and empirical support, and then taught to others in both spoken and written words. He saw the last step as the main distinction between learning and science. Olevi Kull's approach to science relied on two principles: first, linking theory and experiments in challenging settings, e.g., to test the generality of his ideas he often challenged them in multi-layered, mixed-species canopies. Second, he insisted on setting experiments to test assumptions used in quantitative analyses or in explaining an observed outcome; this, at times, led to falsification of commonly held ideas, thus enhancing ecophysiological understanding. After describing Kull's application of these principles, we give a brief synthesis of his most important work, in which he demonstrated through experimentation and modeling how the vertical distribution of leaves in canopies is consistent with the acclimation of the photosynthetic apparatus. We also review some of his findings on the interactive effects of carbon dioxide and ozone on canopy photosynthesis.

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Consequences of elevated CO2 and O3 on birch canopy structure: Implementation of a canopy growth model

Cited by 4 publications

References 61 publications

Effects of light intensity and duration on leaf hydraulic conductance and distribution of resistance in shoots of silver birch (Betula pendula)

Effects of light intensity and duration on leaf hydraulic conductance and distribution of resistance in shoots of silver birch (Betula pendula)

A klímaváltozás emberi jogi aspektusai

Olevi Kull's lifetime contribution to ecology

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