Event Title

Physiological Understanding of Loblolly Pine Growth: Fertilization, Clonal and Interactive Responses

Event Website

http://www.nafew2009.org/

Start Date

23-6-2009 11:10 AM

End Date

23-6-2009 11:30 AM

Description

Plantation loblolly pine is one of the most intensively managed pine forest ecosystems in the world. Throughout this managed system millions of acres are fertilized annually. Much is known about the positive growth and yield responses due to fertilization yet the physiological processes responsible for this growth enhancement remain unclear. For example it has been well established that loblolly pine leaf areas increase greatly when fertilized and the phrase ‘leaves grow trees’ has become well established in loblolly pine management discussions. However, increased leaf area is not a physiological response. Forest industry is beginning to produce, screen and deploy clonal material for plantations. A physiological understanding of the growth response to fertilization is needed for rapid, early, clonal screening and would also allow a basis for genetic marker screening. For a number of years we have been investigating the physiological responses that occur immediately following nitrogen fertilization. Specifically, we have investigated changes in leaf level gas exchange and root respiration in response to fertilization. Through a series of studies spanning nearly ten years we have found some consistent changes in physiology that occur after fertilization that we believe lead to growth enhancement. However, recent studies with clones of loblolly pine suggest that no one physiological model may explain the growth response even in closely related clones. This presentation will synthesize numerous studies and present testable hypothesis for future work.

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Jun 23rd, 11:10 AM Jun 23rd, 11:30 AM

Physiological Understanding of Loblolly Pine Growth: Fertilization, Clonal and Interactive Responses

Plantation loblolly pine is one of the most intensively managed pine forest ecosystems in the world. Throughout this managed system millions of acres are fertilized annually. Much is known about the positive growth and yield responses due to fertilization yet the physiological processes responsible for this growth enhancement remain unclear. For example it has been well established that loblolly pine leaf areas increase greatly when fertilized and the phrase ‘leaves grow trees’ has become well established in loblolly pine management discussions. However, increased leaf area is not a physiological response. Forest industry is beginning to produce, screen and deploy clonal material for plantations. A physiological understanding of the growth response to fertilization is needed for rapid, early, clonal screening and would also allow a basis for genetic marker screening. For a number of years we have been investigating the physiological responses that occur immediately following nitrogen fertilization. Specifically, we have investigated changes in leaf level gas exchange and root respiration in response to fertilization. Through a series of studies spanning nearly ten years we have found some consistent changes in physiology that occur after fertilization that we believe lead to growth enhancement. However, recent studies with clones of loblolly pine suggest that no one physiological model may explain the growth response even in closely related clones. This presentation will synthesize numerous studies and present testable hypothesis for future work.

http://digitalcommons.usu.edu/nafecology/sessions/processes/1