Hurricane Katrina: Impacts on Different Pine Species and Implications for Landowners
by H. Glenn Hughes

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Hurricane Katrina roared through Mississippi on August 29, 2005. In her path, some 1.2 million acres of forestland were damaged. About 2 years worth of annual timber harvest for Mississippi was blown down in one day, with the greatest damage occurring in southeast Mississippi. Hardwood bottomlands, pine sawtimber and recently thinned pine stands were most severely damaged.
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Although hurricane damage to forestland was heaviest near the coast, hurricane force winds (in excess of 73 mph) extended to Meridian, some 140 miles inland. Most of the forestland damaged by Katrina was owned by private landowners.

Not all pine species appeared to be affected equally. Several foresters noted that loblolly pine was most severely affected by high winds. If so, this will have long term implications for landowners as they recover from Katrina. This is particularly important facing reports from the National Weather Service that we are in a period of increased hurricane activity and intensity for the next 15 to 30 years.

Plantations exist in South Mississippi that contain different pine species, were planted in the same year, on the same site and received similar thinning treatments. Analyzing these plantations will allow us to determine differences in hurricane damage among pine species.

The objective of this article is to examine the hurricane damage suffered on two separate Forrest County tracts containing loblolly, slash and longleaf pine planted 20 years ago. All were bare root stock, and all were thinned about 4 years ago. This analysis will help landowners in South Mississippi make informed decisions about species to replant in the aftermath of Katrina.

Methods
Two areas on the Chambliss Tree Farm were planted in 1985 in southern Forrest County; the Slade Tract and the Black Creek Tract. The tracts are about 3 miles apart, and each was planted with loblolly, slash and longleaf pine. Each area was thinned abut 4 years ago to approximately 70 square feet of basal area per acre, a typical density for a first thinning. Loblolly and slash pine were thinned with fifth row thinnings, and longleaf, because of the lower initial basal area, had fewer trees removed selectively.

Hurricane Katrina caused considerable damage in this vicinity. Both areas are in the “Severely Damaged” areas as determined by wind speed. Preliminary estimates for Forrest County were that 30 percent of the timber volume was damaged.

Following Hurricane Katrina, plots were established in each planting. Information was collected on tree diameter, damage (none, snapped, blown over, leaning), product before Katrina, product after Katrina, merchantable height before and after Katrina and site information. Global positioning system (GPS) locations were also collected on each plot.

Damage to Loblolly Pine

Loblolly pine suffered significant damage.

Loblolly pine suffered catastrophic wind damage (Table 1). Across both sites, only 16 percent of the loblolly pines were undamaged after Katrina. Most of the loblolly damage (75.9 percent of all loblolly surveyed) were snapped. Leaning and blown over trees accounted for almost 8 percent of all loblolly surveyed.

The amount and type of damage to loblolly pine resulted in an unmanageable stand. Snapped trees suffered a significant and immediate reduction in quality, sometimes in excess of 90 percent of its pre hurricane value. Chip N Saw trees selling for $20 to $25 per ton before Katrina sold as pulpwood for $2 to $3 per ton if landowners could find a buyer. In addition, snapped trees rapidly lost weight, further decreasing their value because trees are largely sold on a weight basis.

Most of the loblolly was clearcut. This represents a significant financial loss, as a large majority of the value obtained from pine management accrues from production of higher value products (sawtimber) in mature stands.

Table 1: Wind Damage From Hurricane Katrina

Damage to Slash Pine

Slash pine suffered less damage than loblolly pine.

Slash pine suffered less damage than loblolly pine (Table 1). More than half (52.4 percent) of the slash pine inventoried was undamaged. The bulk of the damage, as with loblolly pine, was in snapped trees.

While the damage is significant, there is sufficient undamaged slash pine to retain as a manageable stand. This is critical as landowners have significant time and money invested in such stands, and deciding to clearcut now at salvage prices would further compound an already significant economic loss. Managing the undamaged trees will enable landowners to capitalize on the anticipated increase in stumpage prices once the initial flush in timber is exhausted in the restoration effort.

Damage to Longleaf Pine

Longleaf pine had very little damage.

Longleaf pine suffered the least damage of all species. Across both sites, 64 percent of longleaf surveyed was undamaged (Table 1). Unlike loblolly or slash, leaning trees comprised the greatest type of damage across both sites. Snapped trees were the least frequently encountered type of hurricane damage. This is important, as leaning trees or those blown over by the root system (also called clay rooted) remain alive into the spring, and retain more moisture (hence weight) longer than snapped trees. This creates a wider window of opportunity for salvaging leaning and blown over trees, and provides more income due to higher quality products and higher weights.

As a result of the limited damage, the longleaf stands surveyed can be managed with few modifications. There are isolated pockets of heavy damage, but these could be salvaged and regenerated to create more diverse age classes. This diversity in age classes would help reduce risk.

Several factors probably contributed to longleaf pine's success in surviving hurricane force winds from Katrina. First, the grass stage resulted in longleaf having a smaller diameter and shorter height than loblolly or slash pine. The smaller diameter and height enabled it to be more flexible in high winds, thus reducing damage. Second, the thinning was not a traditional fifth row thinning as in the loblolly and slash stands. Due to the smaller size of longleaf at the time of thinning, and the smaller basal area, the thinning was more selective than with the loblolly or slash thinnings. Isolated trees or small groups of trees were removed instead of entire rows.

Looking Forward
Hurricanes are part of our past, present and future. This type of catastrophic damage will happen again; when is unknown. Landowners, particularly those with land south of Hattiesburg, should consider whether or not loblolly pine is worth the risk. This preliminary analysis illustrates increased risk with loblolly pine, particularly after it has been thinned. Risk-averse landowners might consider planting slash or longleaf.

Although longleaf suffered the least damage, it has its own share of risks and problems. Landowners considering longleaf should be committed to proper site preparation to control competing vegetation, particularly grasses that compete for water and nutrients. Also, longleaf containerized seedling are more expensive than bare root loblolly or slash pine. Landowners considering longleaf, particularly those unfamiliar with its specific requirements, should use a forester experienced with longleaf.

The grass stage in longleaf is less of a problem now than in the past due to containerized seedlings and proper site preparation. However, longleaf will likely be smaller in both diameter and height than loblolly or slash, at least initially.

A considerable reforestation effort faces Mississippi landowners due to hurricane Katrina. Recent federal legislation (H.R. 2863) signed by the President in December 2005 provides funding to landowners through a variety of emergency programs. This study will help landowners as they plan and implement reforestation projects on their property in the wake of Hurricane Katrina.
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H. Glenn Hughes is an Extension Professor with the Mississippi State University Extension Service. He can be reached at P.O. Box 348, Purvis, MS 39475; his email address is ghughes@ext.msstate.edu.