The influence of different management strategies on canopy cover and carbon storage in longleaf pine forests

Longleaf pine (Pinus palustris) is amenable to management using evenor uneven-aged silvicultural methods. However, owing to its relative intolerance of shade, high-density management of longleaf pine is largely restricted to even-aged approaches. This paper uses predictions of stand dynamics from the Forest Vegetation Simulator to compare the flow of selected “ecosystem services” from longleaf pine stands managed under different regimes. Trends in canopy cover (a surrogate for the development of ground-layer vegetation and the ability to conduct frequent prescribed fires) and carbon sequestration were analyzed. Three different management scenarios were compared: 1) an even-aged pulpwood production goal; 2) a combined pulpwood and sawlog goal, also even-aged; and 3) an uneven-aged sawlog goal. Contemporary planting densities were used in the evenaged treatments (400 trees acre [988 ha]), and a moderate residual stocking was chosen for the uneven-aged treatment (BDq, where B=50 ft acre [11.5 m ha], D=20 inch diameter at breast height [50 cm], q=1.2, respectively). Canopy cover was considerably less variable under the unevenaged approach, ranging between 38 and 53%, compared to 0 and 83% for both of the even-aged treatments. The amount of carbon sequestered on-site and in forest products over the 90-year simulation was more similar among treatments than canopy cover, being lowest for the short-rotation evenaged (24.9 tons acre [55.3 tonnes ha]) and highest for the extended-rotation even-aged (32.6 tons acre [72.5 tonnes ha]) regimes; this value was intermediate for uneven-aged management (29.6 tons acre [65.8 tonnes ha]). Thus, in terms of satisfying the joint objectives of maintaining conditions conducive to ground-cover development and natural fire regimes, and sequestering carbon, the uneven-aged scenario performed best among those compared.