Competition reduction is widely considered an effective strategy for mitigating drought impacts. Yet little is known about the efficacy of this strategy on drought-tolerant species, particularly across contrasting silvicultural treatments. We reconstructed annual growth of longleaf pine ( Pinus palustris) from increment cores to evaluate whether silvicultural treatments consistently influenced drought response across three regional droughts (2000, 2006–2007, 2011) at three sites. Drought response was quantified using five indices (resistance, resilience, recovery, recovery rate, average growth reduction). Post-treatment density ranged from ~16 to 18 m 2 ha −1 in control treatments to ~4.7–5.9 m 2 ha −1 in shelterwood methods. Treatment effects were absent for resistance and average growth reduction but significant for resilience, recovery, and recovery rate. Plot-level net change in basal area emerged as the most consistent predictor of post-drought performance. The length of the growing season (as indicated by degree-day indices) was an important predictor of resistance, resilience, and recovery. Overall, resistance, resilience, and recovery were emergent, multidimensional outcomes that were not consistently improved by basal area reduction alone.
Fire is a key driver of secondary succession in northern boreal forests, influencing tree species dominance through variations in fire severity. Mammalian herbivores may modify these successional pathways by selectively browsing regenerating trees. Here, we established paired exclosure and control plots to test effects of native moose ( Alces alces) and hare ( Lepus americanus) on postfire tree growth at five sites in interior Alaska across a gradient of fire severity. Browsing and growth were monitored on tagged individuals of black spruce ( Picea mariana), trembling aspen ( Populus tremuloides), and Alaskan paper birch ( Betula neoalaskana) over 4 years, one decade after a stand-replacing fire. Birch and aspen exhibited increased height growth inside exclosures, while spruce growth was greater outside, indicating species-specific responses linked to herbivore preferences and canopy position. Despite these differences, overall herbivore exclusion had modest effects on tree growth, suggesting that mammalian browsing is unlikely to alter post-fire canopy succession in these boreal forests. These findings enhance understanding of biotic interactions shaping forest recovery under changing fire regimes.
Even-aged silviculture dominates Douglas-fir ( Pseudotsuga menziesii) management in Western Oregon, yet increasing interest in continuous-cover forestry and carbon pricing has renewed attention to the potential economic performance of uneven-aged systems. This study examined the conditions under which uneven-aged Douglas-fir management can become economically competitive with the even-aged management systems in Western Oregon under varying financial and carbon market conditions. Both systems were evaluated using a land expectation value (LEV) framework with identical timber prices, carbon values, and discount rates. For even-aged management, higher planting densities with no thinning regime maximized total LEVs, reaching $13 864.25 ha −1 under a 35-year rotation. The most competitive uneven-aged regime, defined by a residual basal area of 23.0 m 2 ha −1 and a 10-year cutting cycle, achieved a substantially lower LEV of $8635.84 ha −1 . Sensitivity analyses indicate that higher discount rates sharply reduce LEVs under both systems, while higher carbon prices increase LEVs and narrow the profitability gap between management systems. A switching point emerges at 2.96% under lower carbon prices, whereas the highest performing uneven-aged management remained more profitable than the best-performing even-aged regime under the higher carbon price. Overall, uneven-aged management becomes relatively more competitive under low discount rates and higher carbon prices, but even-aged management remains financially dominant in baseline conditions in Western Oregon.
Understanding how management alters stand structural development is essential for improving the productivity of loblolly pine ( Pinus taeda L.) plantations. Although intensive management increases productivity, its effects on tree size inequality and size–growth relationships remain poorly understood. We compared these structural characteristics between extensively managed and intensively managed plantations in the western Gulf Plain, USA. Gini indices (GI) and growth dominance (GD) were calculated for both diameter at breast height (DBH) and height. Generalized additive mixed models were used to assess the effects of stand age, site index (SI), and stand density index (SDI). Intensively managed plantations consistently exhibited lower inequality in both DBH and height than extensively managed plantations, although management had little influence on the relationships of GI with stand age, SI, and SDI. In contrast, GD differed markedly between management regimes. DBH GD shifted from negative to weakly positive during stand development, indicating a transition from small-tree growth advantage to asymmetric competition. Intensive management accelerated this transition and shortened its duration. Height GD remained negative throughout stand development, indicating a persistent growth advantage of shorter trees, although intensive management altered its temporal pattern. GI was significantly associated with GD, but these relationships differed between DBH and height and only accounted for a small proportion of variation. Overall, intensive management fundamentally alters stand structural development, highlighting the need for management strategies that account for changing competitive dynamics in loblolly pine plantations.
Biodiversity data play a central role in the iterative process of adaptive forest management, offering insights into the sustainability of forest practices. Traditional indicators of forest integrity have relied heavily on above ground taxa, primarily vertebrates and plants, which operate across regional to stand level scales. In contrast, below ground and freshwater biomes-- including soil communities, aquatic microbiomes, and deadwood associated taxa--remain comparatively understudied. Recent advances in molecular methods, particularly metabarcoding, have transformed our ability to characterize this biodiversity enabling rapid, comprehensive assessments of community composition from environmental DNA (eDNA) in substrates such as soil, water, and wood. These tools provide opportunities to evaluate how forest management influences ecological processes and to support improved sustainable forest management. This review provides background on the application and utility of metabarcoding for generating biodiversity data in forest ecosystems to inform decision making. We outline the conceptual background of eDNA metabarcoding, survey emerging research specific to forest management, and present a practical workflow from field sampling to biodiversity data generation. By clarifying both the potential and limitations of these methods, this paper aims to equip nonexperts with the understanding needed to confidently interpret metabarcoding results and integrate them into efforts to measure forest integrity.
