destroyed virgin longleaf pine stand lives-on digitally · destroyed virgin longleaf pine stand...

Destroyed Virgin Longleaf Pine Stand Lives-on Digitally

John C. Gilbert, John S. Kush, and Rebecca J. Barlow

17th Biennial Southern Silviculture Research Conference March 5-7, 2013

Shreveport, Louisiana

Gilbert et al 2013 (BSSRC Presentation)

http://www.auburn.edu/

Longleaf Pine (Pinus palustris Mill.)

• Dominated millions of acres

• Important commercial and ecological species

• Perpetuated itself for millions of years

• Many unanswered questions and misconceptions


Historic Range of Longleaf Pine


Flomaton Natural Area (FNA)

• Last remaining virgin stand of longleaf pine in Alabama

• 80 acres

• Privately owned

• Was Located in Flomaton, AL



• Longleaf pine over 200 years old

• Regularly burned until 1950

• Often as part of annual community picnics


Old Growth Longleaf Pine Sites


Old Growth Longleaf Pine Sites

• Varner and Kush 2004

• Highlighted 15 remnant old growth sites

• 0.004% of extant acreage

• 0.00014% of presettlement extent


40+ Years of Fire Suppression

• All burning and fuel management ceased from 1950 until 1994


Restoration Started in 1994 • Flomaton Volunteer Fire Department

called out for a meandering trash fire

• Trash fire killed a significant number of longleaf pine trees

• Questions were raised about why some trees died and others did not

• John Kush at Auburn University was contacted

• Restoration efforts initiated in 1994


Initial Findings

• Unnatural fuel accumulations

• Other southern pines and hardwoods

• The trash fire only killed longleaf pine that were 80 years+


Restoration Begins: Work Over the Next Decade

• Off-site trees were removed

• 5 prescribed fires were carefully applied

• Many lessons learned

• Detailed stand information recorded – Overstory – Understory – Soils


Treatments Created Opportunities • Successful longleaf pine natural regeneration

• Native ground cover understory species returned.

Increasing from 1 herbaceous plant and no native grasses were present to 35 herbaceous species and 7 native grasses were observed in the stand

• Overstory mortality averaged just over 1% per year with nearly 50% of the overstory mortality attributed to lightning strikes


However….

• Despite the successful restoration work and demands to save the stand, the FNA was clear cut in 2008

• Stumps were also removed

• This picture taken was taken of site in 2008


Flomaton’s Obituary 2009

• Obituary for Flomaton: One Less Virgin Longleaf Stand (Alabama)

• Kush, J.S. 2009. Ecological Restoration 27(3 ):-248

• Only the datasheets and digital data remain



FNA Captured in Digital Data • Very unique opportunity to gain more insight into its stand dynamics and

to learn more to aid long-term management of longleaf pine

• GIS (geographical information system) database was created

• Field data converted to digital form including – Stem-map of all longleaf pines greater than or equal to 1 inch dbh (diameter at breast

height). – Crown classes – Ring-counts at breast height – Heights (total and crown heights) – Litter depths

• The entire database provides opportunities for a simulated view of the stand structure in 2 and 3 dimensions


Stem-mapped Longleaf Pine

• Setups recorded with submeter GPS (Global Positioning System)

• Azimuth and distance recorded with a survey laser

• Calculated coordinates for every tree

• 4,167 individual measurements


Stem-mapped Longleaf Pine • Data collected for 4,167 trees

• Diameters range from 0.7 to 32.3

inches dbh

• This illustrates very well the descriptions of the early settlers of the Southeast as to what the original longleaf pine forests looked like: uneven-aged forests, composed of many even-aged stands of varying sizes

• Scaled diameters for stem-mapped longleaf pine at the FNA


Scaled DBH and Crown Classes

• The forest was self-perpetuating where longleaf reproduced itself in openings in the canopy

• Scaled CC by dbh • Dominant • Codominant • Intermediate • Suppressed • No data


Frequent Fire • The original longleaf pine forests

were maintained with frequent growing season fire, every 1-3 years, over most of south Alabama

• Without frequent fire, competing species grow freely and the deep litter layer (decomposed needles, grasses, etc…) develops, a situation presenting potential problems for longleaf pine as happened at FNA J.P. McGuire


Litter Depth at the Base of Trees • Litter and duff depths at the base of

trees approached 16 inches in some cases.

• Allowed feeder roots to colonize the duff layer near the surface

• Use of prescribed fire was very difficult, especially around large, old trees.

• In 4 burns we removed 3 inches of litter and in the final burn nearly 12 inches; as a result, we killed a nearly 300 year old longleaf.

Four Burns

One Burn


Raster Interpolation • The extensive number of points where data were collected on the FNA provides

opportunities to go beyond simply looking at individual points.

• Due to limitations of funding, time, and efficiency, measurements cannot be taken everywhere.

• Data for the known points are used to interpolate or predict values for the surrounding areas where data were not collected. With the good coverage of point data, the inverse distance weighted (IDW) technique was used to calculate the interpolation.

• The combination of known and predicted values are assigned to equally sized grid (raster) across the areas of interest , which creates a continuous surface.

• ArcGIS 10’s 3D Analyst and the Raster Interpolation (IDW) tool was used for the analysis with litter depths, dbh measurements, and ring-counts at breast height. Gilbert et al 2013 (BSSRC Presentation)

Raster Interpolation - Litter Depths • Extensive litter and duff

measurements – Over 3,000 – Depths ranged from 0.5 to 16 inches

• Raster interpolations – Inverse Distance Weighted

• Creates a surface that could be very useful for prescribed burning planning and mop-up

• “Had this been available during our restoration efforts, it would have aided in areas to focus one to prevent the loss of trees has happened in the previous photo”—John Kush


Raster Interpolation – DBH • The surface for diameters shows the

size distribution across the FNA which highlights dense areas and gaps

• Provides information about the variation of trees in the dense areas and gaps

• Basal areas in some of these dense pockets are well over 200 square feet per acre with trees from a variety of sizes


Raster Interpolation – Ring-Count at DBH

• Ring-counts ranged from 3 to trees approaching 300+ years old

• Red heart present


FNA - 3D Representation

• 3 Dimensional Representation using ArcScene

• Educational tool for the future

• Explore stand dynamics and gaps


FNA - 3D Representation - Continued

• Rotate in any direction

• Zoom in and out

• Select individual or groups of trees

• Quick simple statistics Gilbert et al 2013 (BSSRC Presentation)

Exploring Stand Dynamics


Technology and Opportunities

• Robust GIS database

• More data to be explored and incorporated

• 2 and 3 dimension simulations

• Remote sensing


Future Work - Continued • Develop educational tools

– Restoration and conservation professionals

– Students – Private landowners

• Customize trees with recorded metrics

• Create virtual demonstrations

• Continue to explore stand dynamics

and gaps

• Create an online version Gilbert et al 2013 (BSSRC Presentation)

Conclusions

• “The FNA taught us a lot about reintroducing fire to a fire-suppressed stand. In late 2007 or early 2008, the Flomaton Natural Area met its demise at the hand of man.”

• “It withstood nature’s test of time: hurricanes, droughts, lightning strikes, greater than 40 years of fire suppression and then its reintroduction, and much more, but it could not withstand the apathy of many.”—John Kush 2009 Gilbert et al 2013 (BSSRC Presentation)

Conclusions - Continued

• There are still many unanswered questions about longleaf pine stand dynamics, especially for virgin, old growth stands.

• Although we are in the midst of a resurgence of interest in longleaf pine, these efforts often concentrate on planting longleaf while stands like the FNA are lost for future generations. Despite the physical loss of the FNA, it has been captured in digital form.

• The FNA will continue to serve as an educational tool, virtual demonstration, and a beacon for the continued mismanagement and loss of longleaf pine ecosystems.


Questions?


destroyed virgin longleaf pine stand lives-on digitally · destroyed virgin longleaf pine stand...

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