Xi Peng1,2,3, Meifang Zhao4,5,6, Shuguang Liu7,8,9, Wende Yan1,2,3. 1. College of Life Science and Technology, Central South University of Forestry and Technology, Changsha, 410004, Hunan, China. 2. Huitong National Field Station for Scientific Observation and Research of Chinese Fir Plantation Ecosystem in Hunan Province, Huitong, 410015, China. 3. National Engineering Laboratory for Applied Forest Ecological Technology in Southern China, Changsha, 410004, China. 4. College of Life Science and Technology, Central South University of Forestry and Technology, Changsha, 410004, Hunan, China. t20131447@csuft.edu.cn. 5. Huitong National Field Station for Scientific Observation and Research of Chinese Fir Plantation Ecosystem in Hunan Province, Huitong, 410015, China. t20131447@csuft.edu.cn. 6. National Engineering Laboratory for Applied Forest Ecological Technology in Southern China, Changsha, 410004, China. t20131447@csuft.edu.cn. 7. College of Life Science and Technology, Central South University of Forestry and Technology, Changsha, 410004, Hunan, China. shuguang.liu@yahoo.com. 8. Huitong National Field Station for Scientific Observation and Research of Chinese Fir Plantation Ecosystem in Hunan Province, Huitong, 410015, China. shuguang.liu@yahoo.com. 9. National Engineering Laboratory for Applied Forest Ecological Technology in Southern China, Changsha, 410004, China. shuguang.liu@yahoo.com.
Abstract
BACKGROUND: Leaf length and width could be a functioning relationship naturally as plant designs. Single-vein leaves have the simplest symmetrical distribution and structural design, which means that fast-growing single-vein species could interpret the scheme more efficiently. The distribution of leaf length and width can be modulated for better adaptation, providing an informative perspective on the various operational strategies in an emergency, while this mechanism is less clear. Here we selected six age groups of Cunninghamia lanceolata pure forests, including saplings, juveniles, mature, and old-growth trees. We pioneered a tapering model to describe half-leaf symmetric distribution with mathematical approximation based on every measured leaf along developmental sequence, and evaluated the ratio of leaf basal part length to total length (called tipping leaf length ratio). RESULTS: The tipping leaf length ratio varied among different tree ages. That means the changes of tipping leaf length ratio and leaf shape are a significant but less-noticed reflection of trees tradeoff strategies at different growth stages. For instance, there exhibited relatively low ratio during sapling and juvenile, then increased with increasing age, showing the highest value in their maturity, and finally decreased on mature to old-growth transition. The tipping leaf length ratio serves as a cost-benefit ratio, thus the subtle changes in the leaf symmetrical distribution within individuals reveal buffering strategy, indicating the selection for efficient design of growth and hydraulic in their developmental sequences. CONCLUSIONS: Our model provides a physical explanation of varied signatures for tree operations in hydraulic buffering through growth stages, and the buffering strategy revealed from leaf distribution morphologically provides evidence on the regulation mechanism of leaf biomechanics, hydraulics and physiologies. Our insight contributes greatly to plant trait modeling, policy and management, and will be of interest to some scientists and policy makers who are involved in climate change, ecology and environment protection, as well as forest ecology and management.
BACKGROUND: Leaf length and width could be a functioning relationship naturally as plant designs. Single-vein leaves have the simplest symmetrical distribution and structural design, which means that fast-growing single-vein species could interpret the scheme more efficiently. The distribution of leaf length and width can be modulated for better adaptation, providing an informative perspective on the various operational strategies in an emergency, while this mechanism is less clear. Here we selected six age groups of Cunninghamia lanceolata pure forests, including saplings, juveniles, mature, and old-growth trees. We pioneered a tapering model to describe half-leaf symmetric distribution with mathematical approximation based on every measured leaf along developmental sequence, and evaluated the ratio of leaf basal part length to total length (called tipping leaf length ratio). RESULTS: The tipping leaf length ratio varied among different tree ages. That means the changes of tipping leaf length ratio and leaf shape are a significant but less-noticed reflection of trees tradeoff strategies at different growth stages. For instance, there exhibited relatively low ratio during sapling and juvenile, then increased with increasing age, showing the highest value in their maturity, and finally decreased on mature to old-growth transition. The tipping leaf length ratio serves as a cost-benefit ratio, thus the subtle changes in the leaf symmetrical distribution within individuals reveal buffering strategy, indicating the selection for efficient design of growth and hydraulic in their developmental sequences. CONCLUSIONS: Our model provides a physical explanation of varied signatures for tree operations in hydraulic buffering through growth stages, and the buffering strategy revealed from leaf distribution morphologically provides evidence on the regulation mechanism of leaf biomechanics, hydraulics and physiologies. Our insight contributes greatly to plant trait modeling, policy and management, and will be of interest to some scientists and policy makers who are involved in climate change, ecology and environment protection, as well as forest ecology and management.
Authors: V M Savage; L P Bentley; B J Enquist; J S Sperry; D D Smith; P B Reich; E I von Allmen Journal: Proc Natl Acad Sci U S A Date: 2010-12-13 Impact factor: 11.205
Authors: Katherine McCulloh; John S Sperry; Barbara Lachenbruch; Frederick C Meinzer; Peter B Reich; Steven Voelker Journal: New Phytol Date: 2010-02-12 Impact factor: 10.151
Authors: Brendan Choat; Steven Jansen; Tim J Brodribb; Hervé Cochard; Sylvain Delzon; Radika Bhaskar; Sandra J Bucci; Taylor S Feild; Sean M Gleason; Uwe G Hacke; Anna L Jacobsen; Frederic Lens; Hafiz Maherali; Jordi Martínez-Vilalta; Stefan Mayr; Maurizio Mencuccini; Patrick J Mitchell; Andrea Nardini; Jarmila Pittermann; R Brandon Pratt; John S Sperry; Mark Westoby; Ian J Wright; Amy E Zanne Journal: Nature Date: 2012-11-21 Impact factor: 49.962