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Geography, Ecology, Evolutionary Biology, Community Ecology, Evolution, Evolutionary Ecology, and 22 moreForestry, Herpetology, Ornithology, Forest Ecology, Forest Ecology And Management, Vegetation Ecology, Conservation Biology, Zoology, Landscape Ecology, Conservation Ecology, Evolutionary ecology (Ecology), Dendrochronology, Dendroecology, Temperate Forests, Tree Ring, Dendrochronology, Climate Change, Longleaf Pine, Canopy Ecology, Road Ecology, Botany, Biogeography, Biodiversity Research, and Landscape and Land-use-history edit
Longleaf pine (Pinus palustris Mill.) cannot be distinguished from the other southern pines based on wood anatomy alone. A method that involves measuring pith and second annual ring diameters, reported by Arthur Koehler in 1932 (The... more
Longleaf pine (Pinus palustris Mill.) cannot be distinguished from the other southern pines based on wood anatomy alone. A method that involves measuring pith and second annual ring diameters, reported by Arthur Koehler in 1932 (The Southern Lumberman, 145: 36–37), was revisited as an option for identifying longleaf pine timbers and stumps. Cross-section disks of longleaf, loblolly (Pinus taeda L.), and shortleaf (Pinus echinata Mill.) pines were measured and the diameters of their piths and second annual rings plotted against each other. From this plot, longleaf pine could be differentiated from the other two southern pine species, demonstrating that a method established with trees harvested more than 70 years ago is still applicable to standing timber of today. No evidence was found to suggest that different growth rates impact method applicability. In those situations where the second annual ring is intact, but not the pith, very large second annual ring diameters (>40 mm) may identify timbers with a lower probability of being longleaf pine. In addition to the identification of very old lightwood stumps as part of a longleaf pine restoration effort, both methods may be applied to timber identification in historic structures and the niche forest products industry involving the recovery and processing of highly prized longleaf pine logs from river bottoms. Measurements from relicts sampled in this study were consistent with the purported range for longleaf pine in Virginia.
Research Interests:
Redstone Arsenal (RA) is a large federal landholding (15,050 ha) managed by the US Department of the Army located on the Highland Rim of north Alabama. This large landholding provided a unique opportunity to document forest vegetation... more
Redstone Arsenal (RA) is a large federal landholding (15,050 ha) managed by the US Department of the Army located on the Highland Rim of north Alabama. This large landholding provided a unique opportunity to document forest vegetation and development patterns in a region with a paucity of quantitative information. In this study, we quantified land cover types, delineated forest stands on the reserve using a GIS, and assessed forest composition and structural measures. Stands were classed into Pinus, hardwood, mixed Pinus-hardwood, and forested wetland types. The majority of land area in stands ≥ 2 ha was hardwood dominated, while the majority of the land area in stands < 2 ha was Pinus dominated. We used a stratified random scheme to establish sampling points (n = 684) within forest stands through the RA. Pinus taeda, Liquidambar styraciflua, and Quercus phellos were the three most important tree species in the RA forest. Biodiversity for the forest was relatively high with a tree species richness of 57 and diversity (H’) of 2.50. Total forest evenness (J) was 0.62, but this value was lowered by the abundance of Pinus in plantation management. Average stand age was 38 years with a range from 7 to 90 years. Basal area was 22.6 m2 ha-1 and we expect this value to increase with forest age. Significant differences were noted between tree age and height across the three surveyed forest types. Our results provide information on forest conditions in an understudied region.
Research Interests:
Disturbance regimes of many hardwood forests of the eastern United States in the complex stage of development are characterized by localized canopy disturbance events that change fine-scale biophysical conditions. Recently, research has... more
Disturbance regimes of many hardwood forests of the eastern United States in the complex stage of development are characterized by localized canopy disturbance events
that change fine-scale biophysical conditions. Recently, research has demonstrated the importance of gap-scale disturbance processes in secondary hardwood stands of the southern Appalachian Highlands. However, information on canopy disturbance patterns during early developmental stages is required from the broader geographic region for a comprehensive understanding of stand dynamics. The goal of this study was to reconstruct canopy disturbance history for mixed hardwood stands on the Highland Rim of Alabama to elucidate disturbance patterns during early development. We analyzed radial growth from 46 Quercus individuals to reconstruct canopy disturbance history. The majority (67%) of the trees analyzed exhibited release events. In total, 42 releases were detected and some trees experienced multiple events. Of these releases, 28 (67%) were classed as minor and 14 (33%) were classed as major. Mean release duration was 4.00 years 6 0.21 (SE) and the longest release was sustained for eight years. Based on mean release duration, we speculate that most of the canopy gaps were filled by lateral crown expansion rather than subcanopy height growth. We did not document any forest-wide disturbance events; a pattern that may be a regional phenomenon or may be related to forest age. Canopy disturbances became common after ca. 40 years of development. We propose that the frequency of canopy gaps will decrease and the size and magnitude of individual gaps will increase as the stands mature.
that change fine-scale biophysical conditions. Recently, research has demonstrated the importance of gap-scale disturbance processes in secondary hardwood stands of the southern Appalachian Highlands. However, information on canopy disturbance patterns during early developmental stages is required from the broader geographic region for a comprehensive understanding of stand dynamics. The goal of this study was to reconstruct canopy disturbance history for mixed hardwood stands on the Highland Rim of Alabama to elucidate disturbance patterns during early development. We analyzed radial growth from 46 Quercus individuals to reconstruct canopy disturbance history. The majority (67%) of the trees analyzed exhibited release events. In total, 42 releases were detected and some trees experienced multiple events. Of these releases, 28 (67%) were classed as minor and 14 (33%) were classed as major. Mean release duration was 4.00 years 6 0.21 (SE) and the longest release was sustained for eight years. Based on mean release duration, we speculate that most of the canopy gaps were filled by lateral crown expansion rather than subcanopy height growth. We did not document any forest-wide disturbance events; a pattern that may be a regional phenomenon or may be related to forest age. Canopy disturbances became common after ca. 40 years of development. We propose that the frequency of canopy gaps will decrease and the size and magnitude of individual gaps will increase as the stands mature.
Research Interests:
Botany, Landscape Ecology, Geography, Forestry, Conservation Biology, and 12 moreDendroecology, Forest Ecology And Management, Biology, Dendrochronology, Ecology, Vegetation Ecology, Biogeography, Forest Ecology, Temperate Forests, Biodiversity Research, Landscape and Land-use-history, and Alpine and Arctic Research
Removal of canopy dominant trees in temperate closed-canopy forests due to natural or anthropogenic disturbance may allow for the release of co-dominant and sub-canopy trees into the canopy. Historical growth releases of these trees can... more
Removal of canopy dominant trees in temperate closed-canopy forests due to natural or anthropogenic disturbance may allow for the release of co-dominant and sub-canopy trees into the canopy. Historical growth releases of these trees can be reconstructed from the analysis of their annual rings and compared with historical disturbance events to better understand forest dynamics. We applied boundary-line growth patterns, a method for the reconstruction of historical release from disturbance, to annual-ring series of co-dominant longleaf pine in two closed-canopy successional forest sites (Everwoods and Seacock Swamp) the Mid-Atlantic Coastal Plain of southeastern Virginia. The somewhat degraded stands were co-dominated by mixed hardwoods and loblolly pine (Pinus taeda L.) after a long fire-free history. Our study documented recruitment patterns through age-class distribution and reconstructed disturbance events (growth releases) using a modified version of the boundary-line growth method. Ages for all cored individuals at Everwoods (n = 37) ranged from 32–184 years (x = 53 years), and at Seacock Swamp (n = 32), from 56–175 years (x = 94 years). Longleaf pine has failed to recruit over the past two
decades at Everwoods, and over the past half-century at Seacock Swamp, probably due to increased competition and habitat decline in the absence of fire. Boundary-line growth patterns revealed moderate and major release events for longleaf pines at both sites that we linked to anthropogenic disturbances, such as silvicultural operations (1900s to the 1930s) at both sites and logging by the landowner (early 1950s) at Seacock Swamp. We interpreted extremely low growth rates and dramatic growth-change pulses after disturbance as evidence of heavy suppression atypical for this species, which has been conceptualized as shade-intolerant. Our findings fit with other studies that have suggested that longleaf pine may be less shade tolerant than formerly thought, at least in some areas or sites. Applications of the boundary-line growth
patterns method to old-growth and second-growth longleaf pine forests throughout the southeastern U.S. could help to document possible spatial variability in disturbance histories, responses to releases, and suppression patterns.
decades at Everwoods, and over the past half-century at Seacock Swamp, probably due to increased competition and habitat decline in the absence of fire. Boundary-line growth patterns revealed moderate and major release events for longleaf pines at both sites that we linked to anthropogenic disturbances, such as silvicultural operations (1900s to the 1930s) at both sites and logging by the landowner (early 1950s) at Seacock Swamp. We interpreted extremely low growth rates and dramatic growth-change pulses after disturbance as evidence of heavy suppression atypical for this species, which has been conceptualized as shade-intolerant. Our findings fit with other studies that have suggested that longleaf pine may be less shade tolerant than formerly thought, at least in some areas or sites. Applications of the boundary-line growth
patterns method to old-growth and second-growth longleaf pine forests throughout the southeastern U.S. could help to document possible spatial variability in disturbance histories, responses to releases, and suppression patterns.
Research Interests:
Climate and longleaf pine (Pinus palustris P. Mill.) radial growth relationships have been documented within its southern and western distribution. However, knowledge of this relationship is lacking along its northern latitudinal range... more
Climate and longleaf pine (Pinus palustris P. Mill.) radial growth relationships have been documented within its southern and western distribution. However, knowledge of this relationship is lacking along its northern latitudinal range margin (NLRM). Based on the principles of ecological amplitude, limiting factors, and studies of coniferous species in eastern temperate forests of the U.S., we hypothesized that the radial growth of longleaf pine in mixed pine-hardwood forests is responding to winter temperatures in southeastern Virginia. Two longleaf pine chronologies were developed to determine the relationship between radial growth and monthly temperature, precipitation, and Palmer Drought Severity Index (PDSI) via response function analysis (RFA). Results at the 0.05 level yielded significant response function coefficients with a positive response to current winter temperature and precipitation and a negative response to prior August PDSI. In studies of climate and longleaf pine radial growth in other parts of its range, winter temperature and precipitation have not shared a significant positive association with radial growth. Instead current spring and summer precipitation usually share this positive association. These findings add more evidence to an emerging pattern suggesting that winter temperatures contribute to limiting the radial growth of temperate conifers at northern range margins in the Northern Hemisphere.