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Carbon Management in Longleaf Pine

In collaboration with Tim Martin and Wendell Cropper with the University of Florida and Kurt Johnsen, John Butnor, Felipe Sanchez and Chris Maier with the USDA Forest Service, this project will develop a forest carbon cycle model that can be used to evaluate ecological forest management techniques in southeastern U.S. longleaf pine forests and in systems where restoration of longleaf pine ecosystems is the goal.  We will parameterize and link an even-aged longleaf pine model and a single-tree longleaf pine stand model that can accurately and robustly simulate carbon dynamics in longleaf pine in response to the range of management actions, including calibration with extensive field measurements and validation.  The project is in its initial stages so please visit our web site in the future for more information and updates.

Climate Change

Understanding the impact of climate change on southern pine species is important in assessing potential climate change impacts to southern Coastal Plain forests.  Potential changes in temperature and precipitation patterns may influence growth and physiological processes in trees.  This project is studying potential climate change impacts on the physiology of mature longleaf pine, loblolly pine, and slash pine stands in order to provide better predictions for future climate change effects on southeastern forests.
The objectives of this study are to

1. Determine if longleaf pine is better adapted to predicted rising temperatures than loblolly pine and slash pine by measuring in situ photosyntetic temperature optima in mature trees.

2. Compare in situ diurnal patterns in net photosyntesis, stomatal conductance, water use efficiency, and leaf water potential under varying soil moisture conditions between species to assess drought tolerance.

An existing research site, located within the USDA Forest Service Harrison Experimental Forest near Saucier, MS in the DeSoto National Forest is being used for this study.  The site was established in 1960 by the Forest Service for growth and genetics studies on longleaf, slash, and loblolly pine.  This is a thesis project for Will Whitlow at AU and in collaboration with Kurt Johnsen and John Butnor with the USDA Forest Service

Geographic Variation in Longleaf Pine: Improving Deployment of Seed Source to Site

A wider geographic range in longleaf seed sources is now available for planting, including montane sources.  Given the substantial effort underway to restore longleaf pine throughout its native range, more information on site adaptability and the subsequent need for deployment of specific sources to different sites to increase survivability and growth is needed.  Juvenile and mature longleaf pine have been shown to be sensitive to drought and over the next 25 to 50 years, temperatures and the frequency of extreme weather events in the southeastern U.S. are predicted to increase.  These conditions combined with high runoff may reduce the amount of moisture captured and available for tree growth.  Therefore, information on variability in adaptability of different seed sources to drought is also needed to match seed source to site and ensure long-term success of restoration plantings. 

We are collecting preliminary data on seedling variation in drought tolerance, physiological processes, biomass allocation, growth and disease resistance in nine longleaf seed sources generously provided by the International Forest Company.  This study will identify important variables to examine in out-planting studies in addition to standard attributes such as survival, duration of grass stage and brown-spot resistance.  We are seeking support to implement field trials using different seed sources planted in replicated studies in as many sites and states as funding permits.  Please contact Lisa Samuelson if you are interested in supporting this new endeavor to improve longleaf pine restoration!

 

Temperature and Drought Responses in Longleaf, Slash and Loblolly Pine: Comparative Adaptation to Climate Change

Understanding the impact of climate change on southern pine species is important in assessing potential climate change impacts to southern Coastal Plain forests.  Potential changes in temperature and precipitation patterns may influence growth of mature longleaf pine, loblolly pine, and slash pine stands in order to provide better predictions for future climate change effects on southeastern forests.  The objectives of this study are to:

1. Determine if longleaf pine is better adapted to predicted rising temperatures than loblolly pine and slash pine by measuring in situ photosynthetic temperature optima in mature trees.

2. Compare in situ diurnal patterns in net photosynthesis, stomatal conductance, water use efficiency, and leaf water potential under varying soil moisture conditions and between species to assess drought tolerance.

An existing research site, located within the USDA Forest Service Harrison Experimental Forest near Saucier, MS in the DeSoto National Forest will be used for this study.  The site is located 32 km north of Gulfport, MS.  The site was established in 1960 by the Forest Service for growth and genetics studies on longleaf, slash, and loblolly pine.

New Longleaf Genetics Trials

Under the auspices of the North Carolina State Tree Improvement Cooperative (S.E. McKeand) in collaboration with the U.S. Forest Service Southern Research Station (K.H. Johnsen, C.D. Nelson), U.S. Forest Service National Forest Region 8 (B.S. Crane), and the Auburn University Center for Longleaf Pine Ecosystems (L.J. Samuelson), a series of provenance/progeny tests are currently being propagated and will be planted across the Southeast in the early Winter of 2010.  Twelve or more sites will be planted on a combination of industry, private landowner, Forest Service Experimental Forests and University Experimental Forests.  One hundred and fifty one seed sources (mostly open-pollinated families) originating from southern Alabama, northern Alabama, Georgia, Florida, Louisiana, Mississippi, North Carolina, Texas, and Virginia will be planted on all sites.  Seeds are from seed orchards across the region (where progeny have not been tested or minimally tested) as well as some bulk collections from natural stands.  This new set of experiments as well as the seed collections themselves will serve as the backbone of new genetics research on longleaf pine.

Pine Straw Consortium

New initiatives include a proposal to form a pine straw consortium to promote the development and environmental sustainability of the pine straw industry in Alabama and the Southeast.  Annual sales of pine straw in the lawn and garden industry exceed $35 billion and pine straw is in great demand.  An example of the growing importance of pine straw industry is evident in Georgia where in 2006 pine straw contributed over 62 million dollars to Georgia’s economy and in 2009 pine straw contributed 80 million and ranked 25th in GA’s Agriculture Commodities rankings. The pine straw consortium proposes to develop the market by conducting market and economic analyses, create decision support tools to evaluate pine straw production in forest management plans, improve the science of sustainable pine straw production, and develop programs to educate forest owners.  Faculty with expertise in forest biology and forest resource management, economics and marketing, horticulture, sociology and landowner education will provide the expertise to develop this consortium.

Are Longleaf Pine Forest Carbon Sinks?

• Global climate change and the accumulation of carbon dioxide in the atmosphere can be mitigated by the proper management of soils and forests through carbon sequestration.
• Longleaf pine forests and soils sequester large quantities of carbon because of long timber rotations and temperate climate conditions.
• The objective of the project was to examine how forest structure influences the rate of soil respiration to better understand forest management effects on carbon pools.
• Soil respiration was examined in response to:
  1. basal area,
  2. live, dead, coarse, and fine root biomass,
  3. woody debris in the soil,
  4. soil charcoal mass,
  5. litter depth and litter mass,
  6. downed woody debris,
  7. aboveground biomass in woody species,
  8. environmental conditions,
  9. and estimated percent ground cover.

 

 

 

 

 

 

 

Structure and Diversity of Longleaf Pine (Pinus palustris Mill.) Forest Communities in the Mountain Longleaf National Wildlife Refuge, Northeastern Alabama

• The Mountain Longleaf National Wildlife Refuge (MLNWR) has significant acreage of young and old growth mountain longleaf pine.
• The MLNWR has a lack of historical information, therefore, data are needed on forest structure and fuel loads in the Refuge.

• The objectives of the project were to:
  
  1. establish permanent monitoring plots in the Refuge,
  2. document herbaceous and woody vegetation,
  3. and measure biodiversity, forest structure, and fuel loads in longleaf communities with varying fire and management histories.

• Results:
1. Without hardwood control or fire, hardwood encroachment and high duff layers are significantly inhibiting longleaf pine regeneration and development of native herbaceous and grass cover.
2. Only 17 of 48 plots had longleaf pine regeneration.
3. Future monitoring is needed to track regeneration success in response to management activities.
   
   
• Funding provided by the National Fish and Wildlife Foundation (NFWF).