%0 Journal Article %1 PittermannSperry:2003 %A Pittermann, J. %A Sperry, J. %D 2003 %J Tree Physiology %K bibtex-import, citeulikeExport dependance, diameter, embolism, freezebolism, snowgumpapermaybe, temperature %P 907--914 %T Tracheid diameter is the key trait determining the extent of freezing-induced embolism in conifers %U http://www.biology.utah.edu/sperry/pubs/Tree\_Phys\_03.pdf %V 23 %X Hypothesis: freezing-induced embolism is related to conduit diameter

@article{PittermannSperry:2003, abstract = {{Hypothesis: freezing-induced embolism is related to conduit diameter}}, added-at = {2019-03-31T01:14:40.000+0100}, author = {Pittermann, J. and Sperry, J.}, biburl = {https://www.bibsonomy.org/bibtex/2a595ac6eefcf43ca235b3e0493e872a5/dianella}, citeulike-article-id = {1523882}, citeulike-linkout-0 = {http://www.biology.utah.edu/sperry/pubs/Tree\_Phys\_03.pdf}, comment = {(private-note)tracheids air saturation is equivalent to changing tracheid diameter. eh? cut branches put in bags, transported to lab, recut underwater, stored at 4oC for up to 7 days. These guys also did the pressure head thing: 4 to 5 kPa, used distilled filtered water, measured "zero" without pressure head first. they measured conductivity before centrifuge (is this valid, considering what they did to the twigs?), with all the native emboli blasted out, then after the centrifuge. -3oC per 18 min to minimum twig temperatures of btw. -10 and -14oC in 90min. Thawed over the following 90 min roots had larger tracheid diameters than stems. Collected from sites that were well-hydrated, roots never froze. 30um diameter threshold for embolism. P. contorta roots and stems showed no interaction between PLC and minimum freezing temperature. This is expected if bubble formation during freezing is the only cause of PLC. Ginkgo biloba stems showed an effect of minimum temperature on freezing embolism. The additional PLC at lower freezing temperatures was considered unrelated to bubble formation, since the exotherm was at -2C. Concluded that conifers are just as vulnerable to freezebolism as angiosperms. Also concluded that conduit diameter rather than volume or pit structurewas the main determinant of PLC. (But they didn't actually calculate volume so I don't see how they could conclude that. Still, it's the same dude, Sperry, who wrote the paper saying that volume was important in 1992, so he obviously knows what he's talking about.) Centripetal ice formation is observed in these papers: (Sucoff 1969, Ewers 1985, Robson et al. 1988) (Langan et al. 1997) says that bubble formation is independent of ice temperature. Pockman and Sperry 1997 tentatively attributed the effects of temperature on embolism to damage to living parenchyma (did they? Why didn't I mention this below?) "Hence, the increased PLCFT of these angiosperm species characterizes the expected trade-off associated with hydraulically efficient conduits.We extend this by demonstrating that these costs also apply to gymnosperms (Figure 5B). Specifically, organs such as roots and trunks, and those species that rarely freeze such as T. distichum, exhibit the highest Ks and thus the greatest PLCFT."}, interhash = {1182ac07043be25562b7844416061eba}, intrahash = {a595ac6eefcf43ca235b3e0493e872a5}, journal = {Tree Physiology}, keywords = {bibtex-import, citeulikeExport dependance, diameter, embolism, freezebolism, snowgumpapermaybe, temperature}, pages = {907--914}, posted-at = {2007-07-31 06:50:21}, priority = {2}, timestamp = {2019-03-31T01:16:26.000+0100}, title = {{Tracheid diameter is the key trait determining the extent of freezing-induced embolism in conifers}}, url = {http://www.biology.utah.edu/sperry/pubs/Tree\_Phys\_03.pdf}, volume = 23, year = 2003 }