Anpassung von Pinus contorta-Provenienzen an extreme Klimaereignisse
Zusammenfassung der Projektergebnisse
To identify potential climate change risks for different latitudinal populations, we analyzed the growth response to a severe drought event on the three southern-most experimental sites indetail. We found that the northern, boreal provenances were especially susceptible to drought, indicating that these trees may be subject to increased drought-stress in a warmer future. This result is important because it complements previous research on boreal trees, which indicated an increase in growth in the north through an extended growing season. Our results provide a warning sign, because poor drought tolerance might counteract any positive climate change effects. The underlying mechanisms were explored through stable isotope- and wood anatomic analysis. We found that central and southern interior populations had the largest hydraulic conductivity, whereas the US-group and the northern group had lower hydraulic conductivity. Similarly, stable isotope analysis indicates that the central and southern interior populations used water more efficiently. This is indicating that stomata control, rather than hydraulic safety of the xylem pipeline, is responsible for drought tolerance in some populations of lodgepole pine. This strategy has been successful in the past for the central and southern interior populations, since these populations are also the top growth performers. However, this physiological strategy will not remain successful under a warmer, drier future, because it also implies increasing risk of cavitation from overly negative water pressures in the xylem, which breaks the water chain flowing to the photosynthesizing crown. This could lead directly to higher tree mortality across the central and southern interior areas of British Columbia. With stomata remaining closed under dry conditions, even surviving trees may nevertheless suffer from carbon starvation. This physiological stress reduces forest health and could lead to an outbreak of forest pests, similar to the devastating Mountain Pine Beetle epidemic that affected more than 17.5 million hectares of forested land in British Columbia alone. Although the current forest management strategy involving restrictive seed zones and seed transfer guidelines may have worked to date, our results indicate that changes in seed selection and forest management are needed. Indeed, judicious northward seed transfer may reduce productivity mildly, but can also safeguard the forests against the expected increase in temperatures and drought frequency and severity. These results provide an example of how drier future climate condition may affect tree species throughout there range.
Projektbezogene Publikationen (Auswahl)
- (2014) Growth of Lodgepole Pine Populations under Drought: Climate Change Adaptation Strategies. Tree Rings in Archaeology, Climatology and Ecology (TRACE 2014), May 6-10, 2014, Aviemore, Scottish Highlands, United Kingdom. May 9, 2014
Isaac-Renton M, Montwé D, Hamann A, Spiecker H
- (2014) Pinus contorta provenances for a changing climate: Growth response to drought in a genetic field trial. Wood Anatomy and Tree-Ring Ecology 2014Workshop, Klosters, Switzerland, Nov 26, 2014
Montwé D, Isaac-Renton M, Hamann A, Spiecker H
- (2014) Resistant and resilient Lodgepole pine provenances for a changing climate: Growth and hydraulic response to drought in a genetic field trial. XXIV IUFRO World Congress 2014, Oct 5-11, 2014, Salt Lake City, United States of America, Oct 9, 2014
Montwé D, Isaac-Renton M, Hamann A, Spiecker H
- (2015) Using steam to reduce artifacts in micro sections prepared with corn starch. Dendrochronologia, 35:87-90
Montwé D, Isaac-Renton M, Hamann A, Spiecker H
(Siehe online unter https://doi.org/10.1016/j.dendro.2015.07.003) - (2016) Drought tolerance and growth in populations of a wide ranging tree species indicate climate change risks for the boreal north. Global Change Biology
Montwé D, Isaac-Renton M, Hamann A, Spiecker H
(Siehe online unter https://doi.org/10.1111/gcb.13123) - (2016) Mechanisms underlying genetic differences in drought response: a dual-isotope and wood anatomy approach. Third American Dendrochronology Conference (Ameridendro 2016), Mendoza, Mar 28-Apr1, 2016
Isaac-Renton M, Montwé D, Hamann A, Spiecker H, Cherubini P, Treydte K
- (2016) Using Combining provenance trials, functional wood anatomy and dual-isotope analyses to evaluate the risks associated with differing reforestation strategies for a warmer climate in North America. IUFRO 4.04.07 (Risk Analysis). Perception, Prection, Action: Managing risk in uncertain times. Freiburg, Germany, April 21-23, 2016
Isaac-Renton M, Montwé D, Hamann A, Spiecker H, Cherubini P, Treydte K
- (2016) Using stable isotopes and functional wood anatomy to identify underlying mechanisms of drought tolerance in different provenances of lodgepole pine. European Geosciences Union General Assembly 2016, Vienna, Austria, April 17-22, 2016
Isaac-Renton M, Montwé D, Hamann A, Spiecker H, Cherubini P, Treydte K
