Dataset Information

Increased water use efficiency does not prevent growth decline of Pinus canariensis in a semi-arid treeline ecotone in Tenerife, Canary Islands (Spain).

ABSTRACT:

Key message

Intrinsic water-use efficiency of Pinus canariensis (Sweet ex Spreng.) growing at a semi-arid treeline has increased during the past 37 years. Tree-ring width by contrast has declined, likely caused by reduced stomatal conductance due to increasing aridity.

Context

Rising atmospheric CO₂ concentration (C_a ) has been related to tree growth enhancement accompanied by increasing intrinsic water-use-efficiency (iWUE). Nevertheless, the extent of rising C_a on long-term changes in iWUE and growth has remained poorly understood to date in Mediterranean treeline ecosystems.

Aims

This study aimed to examine radial growth and physiological responses of P. canariensis in relation to rising C_a and increasing aridity at treeline in Tenerife, Canary Islands, Spain.

Methods

We evaluated temporal changes in secondary growth (tree-ring width; TRW) and tree ring stable C isotope signature for assessing iWUE from 1975 through 2011.

Results

Precipitation was the main factor controlling secondary growth. Over the last 36 years P. canariensis showed a decline in TRW at enhanced iWUE, likely caused by reduced stomatal conductance due to increasing aridity.

Conclusion

Our results indicate that increasing aridity has overridden the potential CO₂ fertilization on tree growth of P. canariensis at its upper distribution limit.

SUBMITTER: Brito P

PROVIDER: S-EPMC4961253 | biostudies-literature | 2016 Sep

REPOSITORIES: biostudies-literature

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Publications

Increased water use efficiency does not prevent growth decline of <i>Pinus canariensis</i> in a semi-arid treeline ecotone in Tenerife, Canary Islands (Spain).

Brito Patricia P Grams Thorsten E E TE Matysssek Rainer R Jimenez Maria S MS Gonzalez-Rodríguez Agueda M AM Oberhuber Walter W Wieser Gerhard G

Annals of forest science 20160607 3

<h4>Key message</h4>Intrinsic water-use efficiency of <i>Pinus canariensis</i> (Sweet <i>ex</i> Spreng.) growing at a semi-arid treeline has increased during the past 37 years. Tree-ring width by contrast has declined, likely caused by reduced stomatal conductance due to increasing aridity.<h4>Context</h4>Rising atmospheric CO<sub>2</sub> concentration (<i>C<sub>a</sub></i> ) has been related to tree growth enhancement accompanied by increasing intrinsic water-use-efficiency (iWUE). Nevertheless ...[more]

PMID: 27482149

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