In a research study of underplanted longleaf pine seedling growth on the Southern Research Station’s Palustris Experimental Forest, Hurricane Laura uprooted and snapped many trees in the slash pine overwood. Fortunately, less damage was done to a second installation of the study on the nearby Louisiana Department of Wildlife and Fisheries Little River Wildlife Management Area. Photo by Mary Anne Sword Sayer.
Forest landscapes are constantly changed by natural disturbances, and the piney woods of Louisiana’s Kisatchie National Forest are no exception. Extreme wind events recently reshaped portions of the forest’s 182,000-acre Calcasieu Ranger District, which falls within Rapides and Vernon parishes. A 60-mile tornado path in December 2019 devastated 2,500 aces of pine and hardwood timber near Kincaid and Valentine lakes. With summer’s end, 75% of this loss was salvaged only to be followed by hurricanes Laura and Delta destroying an additional 95,000 acres across the forest. Light to moderate hurricane damage also occurred across 200,000 of the forest’s acreage. Immediate actions of local U.S. Department of Agriculture Forest Service staff and the Southern Area Incident Management Team Gold ensured the safety of nearby landowners, cleared roads of downed timber, and began an assessment of timber losses. They are currently guiding salvage and reforestation efforts.
When Mother Nature took aim at the majestic pines of Kisatchie National Forest (KNF), timber losses were lamented and rightly so. Most downed KNF timber ranged in age between 60 and 100 years of age. The rotation age of Kisatchie’s loblolly pine is 80 years, and that of shortleaf and longleaf pine is 120 years, indicating much of this lost resource was in its prime. Of equal concern are storm effects on unique nontimber assets. For example, the KNF is home to a showcase of conservation focused on restoring its once vast longleaf pine ecosystems.
Longleaf restoration success on the Vernon and Evangeline units was not only impacted by tree loss but also by disruption of a ground layer dominated by plants such as bluestem grasses that provide fuel uniformity during prescribed fires. Longleaf pine ecosystems require open stands filtering sunlight to the forest floor as well as frequent fires to perpetuate native flora and fauna. Recent hurricanes pummeled parts of the Calcasieu Ranger District where decades of dedicated management re-created a longleaf pine landscape like that cutover in the early 1900s. Both the Calcasieu Ranger District and Fort Polk Military Base in Vernon Parish contain important reference ecosystems that provide examples of native upland and flatwoods longleaf pine forests. Information from these distinct forests guides longleaf pine restoration in the western Gulf region and is one reason why this part of Vernon Parish is highlighted as a significant landscape in the America’s Longleaf Restoration Initiative. Over coming years, ground-layer recovery will be monitored and prescribed fires will be tailored to reestablish the cycle of sunlight, fuel production and fire that sustains these ecosystems.
Efforts to conserve KNF’s federally listed species, such as the red-cockaded woodpecker (RCW), were also set back by Louisiana’s late summer hurricanes. Artificial cavities are commonly used to enhance roosting and nesting habitat within RCW clusters, which can contain as many as 20 mature trees. The Calcasieu Ranger District currently monitors close to 300 active RCW clusters. Many cluster trees with artificial cavities snapped at a height of about 22 feet where cavities were inserted. As hurricanes Laura and Delta advanced, their wake contained displaced RCW clusters amid timber debris. As soon as it was safe, chainsaw crews cut paths through the downed trees to access damaged RCW clusters. The goal was insertion of new cavities in surviving trees near affected RCW clusters to shelter displaced birds. Rapid action to save Kisatchie’s RCW clusters not only preserved long-term efforts to grow a healthy RCW population but also ensured these clusters would continue providing breeding pairs to enrich RCW populations throughout longleaf country as restoration efforts continue.
Planted seedlings are vital to longleaf pine restoration, and the Palustris Experimental Forest on 7,500 acres of the Calcasieu Ranger District is credited with a legacy of experiments leading to modern-day containerized seedlings and seasonal prescribed fire guidelines. In addition to sustaining stands that feed current longleaf pine stem growth models, this experimental forest now serves as an outdoor longleaf pine laboratory. While Hurricane Laura’s winds in excess of 100 mph toppled intermittent trees throughout the Palustris, they caused sweeping damage — by uprooting and snapping — to a new stand conversion study designed to optimize longleaf seedling growth under the partial shade of mature slash pines. An assessment of overwood damage indicated that recovery as a replicated study is not possible. This five-year effort of the Forest Service’s Southern Research Station and Kisatchie National Forest is considered a significant nontimber casualty of Hurricane Laura. Elsewhere on the Palustris Experimental Forest, tree damage is being inventoried with information added to long-term data sets.
Also impacted by Hurricane Laura was the 566-acre Stuart Seed Orchard on the Catahoula Ranger District in Grant Parish, where loblolly, shortleaf, longleaf and slash pinecones are collected annually. Each tree in the orchard is a first- or second-generation selection that was reproduced vegetatively. This is called a ramet. The orchard’s cones supply a portion of the seed to regenerate southern pines throughout the Southeast and are central to shortleaf and longleaf restoration efforts in the western Gulf region. In addition to wind-loss of the immature 2020 cone crop slated for harvest in late September, 362 cone-producing ramets were destroyed or severely damaged by Hurricane Laura. After extensive orchard cleanup, lost ramets will be replaced by those most recently selected for superior vigor in the western Gulf region.
Beyond wind-thrown timber, delayed loss of scattered trees throughout KNF is likely to occur over the next several years. Visible tree hazards within recreation areas, on trails and adjacent to roads were immediately addressed by a partnership between KNF and the U.S. Forest Service Forest Health Protection (FHP) Alexandria Field Office. Most of this work was completed by midfall, allowing many popular hunting camps, campgrounds and trails to reopen. Presently, a few extensively damaged recreation areas on the KNF remain closed. Special funding at the national level has been requested to aid these repairs. Extreme wind that stretches and twists mature trees can cause “hidden” damage that reduces the flow of water from roots to shoots. Whether this damage leads to water stress followed by poor tree health and insect or disease susceptibility depends on multiple factors, such as rainfall, stand density and soil type. This damage lag causes considerable concern when patches of trees surviving a tornado or hurricane later experience water stress, which, in turn, may attract insect pests, such as bark beetles. Recently installed research where 2019 tornado damage occurred on the KNF is being conducted by the Southern Research Station to predict the likelihood of a post-tornado bark beetle outbreak in stands of different densities. Results will help KNF silviculturists stay one step ahead of bark beetle infestations after future tornadoes.
Throughout the Kisatchie National Forest, red cockaded woodpecker cavity trees are identified by white bands. Hurricane Laura caused many cluster trees with artificial cavities to snap at the tree height of cavity installation. Photo by Matt Pardue, KNF Wildlife Biologist.
Mary Anne S. Sayer is a research scientist at the U.S. Department of Agriculture Forest Service Southern Research Station in Pineville.