Season of burn and nutrient losses in a longleaf pine ecosystem

2004 ◽  
Vol 13 (4) ◽  
pp. 443 ◽  
Author(s):  
L. R. Boring ◽  
J. J. Hendricks ◽  
C. A. Wilson ◽  
R. J. Mitchell
Keyword(s):  
Longleaf Pine ◽  
Mineral Soil ◽  
Soil Surface ◽  
Growing Season ◽  
Plant Litter ◽  
N Fixation ◽  
Nutrient Pools ◽  
Fire Cycle ◽  
Dormant Season

Fire regulates the structure and function of longleaf pine ecosystems, including potential nutrient controls on productivity, forest floor and groundcover nutrient pools, and nutrient availability. Little is known about comparative influences of seasonality of fire, litter types, and mass on N and P balance and soil processes in longleaf pine ecosystems. This study primarily addresses the hypothesis that nutrient volatilization during growing season burning, due to combustion of live biomass, exceeds losses from winter burning of standing dead plant litter. Summer and winter burns were conducted experimentally in different groundcover types with ambient, double-ambient and no litter loadings to contrast 2–3 years of litter accumulation with very low and high fuels. As a comparison, the seasonal burns were repeated with fuel and temperature measurements on sites that had actual fuel accumulations ranging from 1 to 3 years following the last fire. Peak fire temperatures and duration of burning were similar, but with high variation across groundcover types and seasons due to variation in fuel moisture content. The highest pine litter loadings produced maximum mineral soil/litter interface temperatures that never exceeded 700°C. Groundcovers without pine litter burned incompletely and with low temperatures. Biomass and N content were greater in summer groundcover than winter groundcover, and were greater in wiregrass than old-field groundcover. More N was lost from growing season burning as biomass had higher N in green foliage at that time. With ambient litter loadings, mass losses were 88–94% of total litter and groundcover. Percentages of N lost were comparable (80–90% across all groundcovers and seasons), but amounts of N lost were below that estimated to be replenished by legume N fixation and regional atmospheric deposition over a dormant season prescribed fire cycle. Net N balances with growing season fire were generally negative only if growing season burning was projected exclusively over the long-term. P content was not significantly different among groundcovers, but summer standing stocks were higher than winter. No P losses were detected with any experimental treatments and, following burning, all P was returned to soil pools, attributable to soil surface temperatures remaining largely below 700°C. We conclude that frequent, dormant season, or even variable season burning should not seriously deplete long-term nitrogen balance of longleaf pine ecosystems.

Analysis of litter decomposition in an alpine tundra

1998 ◽  
Vol 76 (7) ◽  
pp. 1295-1304 ◽  
Author(s):  
David M Bryant ◽  
Elisabeth A Holland ◽  
Timothy R Seastedt ◽  
Marilyn D Walker
Keyword(s):  
Mass Loss ◽  
Litter Decomposition ◽  
Growing Season ◽  
Plant Litter ◽  
Decay Rates ◽  
Alpine Tundra ◽  
Litter Decay ◽  
Root Litter ◽  
Nitrogen Additions

Decomposition of plant litter regulates nutrient cycling and transfers of fixed carbon to soil organic matter pools in terrestrial ecosystems. Climate, as well as factors of intrinsic litter chemistry, often govern the rate of decomposition and thus the dynamics of these processes. Initial concentrations of nitrogen and recalcitrant carbon compounds in plant litter are good predictors of litter decomposition rates in many systems. The effect of exogenous nitrogen availability on decay rates, however, is not well defined. Microclimate factors vary widely within alpine tundra sites, potentially affecting litter decay rates at the local scale. A controlled factorial experiment was performed to assess the influence of landscape position and exogenous nitrogen additions on decomposition of surface foliage and buried root litter in an alpine tundra in the Front Range of the Rocky Mountains in Colorado, U.S.A. Litter bags were placed in three communities representing a gradient of soil moisture and temperature. Ammonium nitrate was applied once every 30 days at a rate of 20 g N·m-2 during the 3-month growing season. Data, as part of the Long-Term Inter-site Decomposition Experiment Team project, were analyzed to ascertain the effects of intrinsic nitrogen and carbon fraction chemistry on litter decay in alpine systems. Soil moisture was found to be the primary controlling factor in surface litter mass loss. Root litter did not show significant mass loss following first growing season. Nitrogen additions had no effect on nitrogen retention, or decomposition, of surface or buried root litter compared with controls. The acid-insoluble carbon fraction was a good predictor of mass loss in surface litters, showing a strong negative correlation. Curiously, N concentration appeared to retard root decomposition, although degrees of freedom limit the confidence of this observation. Given the slow rate of decay and N loss from root litter, root biomass appears to be a long-term reservoir for C and N in the alpine tundra.Key words: litter decomposition, alpine tundra, nitrogen deposition, LIDET, Niwot Ridge.

scholarly journals Seasonality of Biennial Burning Has No Adverse Effects on Mature Longleaf Pine Survival or Productivity

2021 ◽  
Vol 4 ◽  
Author(s):  
John L. Willis ◽  
Ajay Sharma ◽  
John S. Kush
Keyword(s):  
United States ◽  
Prescribed Burning ◽  
Fire Regime ◽  
Management Practice ◽  
Longleaf Pine ◽  
Volume Growth ◽  
Pinus Palustris ◽  
Size Class ◽  
Dormant Season

Emulating natural disturbance has become an increasingly important restoration strategy. In the fire-maintained woodlands of the southeastern United States, contemporary restoration efforts have focused on approximating the historical fire regime by burning at short intervals. Due to concerns over escape and damage to mature trees, most prescribed burning has occurred in the dormant season, which is inconsistent with the historical prevalence of lightning-initiated fire in the region. This discordance between contemporary prescribed burning and what is thought to be the historical fire regime has led some to question whether dormant season burning should remain the most common management practice; however, little is known about the long-term effects of repeated growing season burning on the health and productivity of desirable tree species. To address this question, we report on a long-term experiment comparing the effects of seasonal biennial burning (winter, spring, and summer) and no burning on the final survival status, height, diameter, and volume growth of 892 mature longleaf pine (Pinus palustris) over 23 years in three mature even-aged stands in southern Alabama, United States. Overall, longleaf pine survival across all treatments averaged 81 ± 2% [s.e]. Among seasonal burn treatments, survival was highest in the spring burns (82 ± 4%) but did not vary significantly from any other treatment (summer – 79 ± 4%, winter – 81 ± 4%, unburned – 84 ± 4%). However, survival was statistically influenced by initial diameter at breast height, as survival of trees in the largest size class (30 cm) was 40% higher than trees in the smallest size class (5 cm). Productivity of longleaf pine was not significantly different among treatment averages in terms of volume (38.9–44.1 ± 6.0 m3 ha–1), diameter (6.0–6.7 ± 0.3 cm), and height (2.5–3.4 ± 0.4 m) growth. Collectively, our results demonstrate that burning outside the dormant season will have little impact on mature longleaf pine survival and growth. This finding has important implications for the maintenance of restored southeastern woodlands, as interest in burning outside the dormant season continues to grow.

scholarly journals Hydrologic Impacts of Logging an Appalachian Watershed Using West Virginia's Best Management Practices

1997 ◽  
Vol 14 (4) ◽  
pp. 207-218 ◽  
Author(s):  
James N. Kochenderfer ◽  
Pamela J. Edwards ◽  
Frederica Wood
Keyword(s):  
Best Management Practices ◽  
Management Practices ◽  
Basal Area ◽  
Growing Season ◽  
First Year ◽  
Best Management ◽  
Hydrologic Impacts ◽  
Dormant Season ◽  
Understory Shrubs

Abstract A 39 ha gauged watershed located in north-central West Virginia near Parsons was cut to a 35.5 cm stump diameter and logged using wheeled skidders to evaluate the effectiveness of West Virginia's Best Management Practices (BMPs). Roads initially occupied 10.6% of the watershed, but this percentage is decreasing as much of the original road prism reverts to forest. Reducing basal area by 44% in stems 2.54 cm dbh and larger had a negligible effect on maximum growing season stream temperatures, apparently because the stream remained shaded by residual trees and understory shrubs growing along it. Both growing season peakflows and total stormflow had small but significant increases due to treatment. Dormant season stormflows did not increase significantly. Although mean monthly exports of suspended sediment doubled the first year when the area was being logged, they remained within the range reported for carefully managed areas in the East. Sediment exports returned to pretreatment levels by the third posttreatment year. Long-term projections of current exports rates indicate that sediment exports from harvesting operations (3 entries) during a 100 yr rotation will account for less than 5% of the total sediment exported from the study watershed. Nitrate exports increased significantly during most of the monitored posttreatment years, but fertilizer applied to the roads during grass seeding is believed to have contributed to these increases. Actual concentration values remained low, with maximum concentrations well below standards for potable water. Calcium concentrations also increased during most years, but road liming during seeding probably was responsible for most of this increase. The BMPs used in this study were effective in minimizing adverse impacts to soil and water resources. North. J. Appl. For. 14(4):207-218.

SOIL MICROARTHROPODS IN LONG-TERM NO-TILLAGE AND CONVENTIONAL TILLAGE CORN PRODUCTION

1990 ◽  
Vol 70 (4) ◽  
pp. 641-653 ◽  
Author(s):  
J. P. WINTER ◽  
R. P. VORONEY ◽  
D. A. AINSWORTH
Keyword(s):  
Zea Mays ◽  
Crop Production ◽  
Soil Surface ◽  
Conventional Tillage ◽  
Plant Litter ◽  
Natural Soil ◽  
No Tillage ◽  
Soil Microarthropods ◽  
Organic C

Cultivation is known to reduce the number and diversity of microarthropod (Acarina and Collembola) populations from levels observed under natural forest or grassland vegetation. Under no-tillage crop production, the soil remains relatively undisturbed and plant litter decomposes at the soil surface, much like in natural soil ecosystems. The objective of this study was to investigate whether microarthropod populations under long-term (19 yr) continuous corn (Zea mays L.) production were increased by no-tillage (NT) vs. conventional tillage (CT; moldboard plow and harrowing) management. Numbers of microarthropods were also obtained from a soil managed as the CT treatment for 15 yr until seeding to bromegrass (Bromus inermus L.) hay for the last 4 yr. During the growing seasons over 2 yr, soil cores were taken every 2–3 wk and extracted for microarthropods using a high gradient extractor. The surface 5 cm of soil was sampled during the first year. All three treatments were different (P < 0.05), with bromegrass, NT and CT soils containing respectively, 15.9, 12.4, and 5.8 microarthropods × 1000 m−2 of which 84, 69, and 70% were Acarina. In the second year, the surface 15 cm was sampled and the number of microarthropods in the corn soils was similar (P < 0.05), containing 33.6 microarthropods × 1000 m−2, 92–98% of which were Acarina. However, microarthropods and soil organic-C were more concentrated in the surface 5 cm of soil in NT than CT. The soil under bromegrass contained 1.3 times more microarthropods (99% were Acarina) than under continuous NT and CT corn. Thus, when examined to a depth of 15 cm, 19 yr of NT corn did not increase the size of the microarthropod populations compared to CT, whereas production of bromegrass hay for 3–4 yr following long-term continuous CT corn did increased microarthropod numbers. Key words: Microarthropods, Collembola, Acarina, Zea mays, Bromus inermus, no-tillage, conservation tillage, soil carbon

scholarly journals Drivers of long-term variability in CO<sub>2</sub> net ecosystem exchange in a temperate peatland

2014 ◽  
Vol 11 (10) ◽  
pp. 14981-15018 ◽  
Author(s):  
C. Helfter ◽  
C. Campbell ◽  
K. J. Dinsmore ◽  
J. Drewer ◽  
M. Coyle ◽  
...  
Keyword(s):  
Carbon Sink ◽  
Ecosystem Respiration ◽  
Net Ecosystem Exchange ◽  
Growing Season ◽  
Sink Strength ◽  
Co2 Uptake ◽  
Annual Variability ◽  
Dormant Season ◽  
Carbon Dioxide Co2

Abstract. Land–atmosphere exchange of carbon dioxide (CO2) in peatlands exhibits marked seasonal and inter-annual variability, which subsequently affects the carbon sink strength of catchments across multiple temporal scales. Long-term studies are needed to fully capture the natural variability and therefore identify the key hydrometeorological drivers in the net ecosystem exchange (NEE) of CO2. NEE has been measured continuously by eddy-covariance at Auchencorth Moss, a temperate lowland peatland in central Scotland, since 2002. Hence this is one of the longest peatland NEE studies to date. For 11 yr, the site was a consistent, yet variable, atmospheric CO2 sink ranging from −5.2 to −135.9 g CO2-C m−2 yr−1 (mean of −64.1 ± 33.6 g CO2-C m−2 yr−1). Inter-annual variability in NEE was positively correlated to the length of the growing season. Mean winter air temperature explained 87% of the inter-annual variability in the sink strength of the following summer, indicating a phenological memory-effect. Plant productivity exhibited a marked hysteresis with respect to photosynthetically active radiation (PAR) over the growing season, indicative of two separate growth regimes. Ecosystem respiration (Reco) and gross primary productivity (GPP) were closely correlated (ratio 0.74), suggesting that autotrophic processes were dominant. Whilst the site was wet most of the year (water table depth <5 cm) there were indications that heterotrophic respiration was enhanced by drought, which also depressed GPP. NEE was compared to 5 other peatland sites which have published long-term NEE records. The CO2 uptake rate during the growing season was comparable to 3 other European sites, however the emission rate during the dormant season was significantly higher.

scholarly journals Fire Season, Overstory Density and Groundcover Composition Affect Understory Hardwood Sprout Demography in Longleaf Pine Woodlands

Forests ◽  
2018 ◽  
Vol 9 (7) ◽  
pp. 423 ◽  
Author(s):  
Andrew Whelan ◽  
Seth Bigelow ◽  
Mary Nieminen ◽  
Steven Jack
Keyword(s):  
Ecosystem Management ◽  
Prescribed Fire ◽  
Longleaf Pine ◽  
Growing Season ◽  
Fire Season ◽  
Fire Intensity ◽  
Seasonal Timing ◽  
Closed Canopy ◽  
Dormant Season ◽  
Global Increase

Seasonal timing of prescribed fire and alterations to the structure and composition of fuels in savannas and woodlands can release understory hardwoods, potentially resulting in a global increase of closed-canopy forest and a loss of biodiversity. We hypothesized that growing-season fire, high overstory density, and wiregrass presence in longleaf pine woodlands would reduce the number and stature of understory hardwoods, and that because evergreen hardwoods retain live leaves, dormant-season fire would reduce performance and survival of evergreen more than deciduous hardwoods. Understory hardwood survival and height were monitored over seven years in longleaf pine woodlands in southwest Georgia with a range of overstory density, groundcover composition, and season of application of prescribed fire. Hardwood stem survival decreased with increasing overstory density, and deciduous hardwoods were more abundant in the absence of wiregrass. Contrary to expectations, evergreen hardwood growth increased following dormant-season fire. Differences in hardwood stem survival and height suggest that low fire intensity in areas with low overstory density increase the risk that hardwoods will grow out of the understory. These results indicate a need for focused research into the effects of groundcover composition on hardwood stem dynamics and emphasize that adequate overstory density is important in longleaf ecosystem management.

scholarly journals Fire, land cover, and temperature drivers of bat activity in winter

Fire Ecology ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Marcelo H. Jorge ◽  
Sara E. Sweeten ◽  
Michael C. True ◽  
Samuel R. Freeze ◽  
Michael J. Cherry ◽  
...  
Keyword(s):  
Land Cover ◽  
Habitat Management ◽  
Deciduous Forest ◽  
Pinus Palustris ◽  
Growing Season ◽  
Early Spring ◽  
Bat Activity ◽  
White Nose Syndrome ◽  
Dormant Season ◽  
Wind Energy Development

Abstract Background Understanding the effects of disturbance events, land cover, and weather on wildlife activity is fundamental to wildlife management. Currently, in North America, bats are of high conservation concern due to white-nose syndrome and wind-energy development impact, but the role of fire as a potential additional stressor has received less focus. Although limited, the vast majority of research on bats and fire in the southeastern United States has been conducted during the growing season, thereby creating data gaps for bats in the region relative to overwintering conditions, particularly for non-hibernating species. The longleaf pine (Pinus palustris Mill.) ecosystem is an archetypal fire-mediated ecosystem that has been the focus of landscape-level restoration in the Southeast. Although historically fires predominately occurred during the growing season in these systems, dormant-season fire is more widely utilized for easier application and control as a means of habitat management in the region. To assess the impacts of fire and environmental factors on bat activity on Camp Blanding Joint Training Center (CB) in northern Florida, USA, we deployed 34 acoustic detectors across CB and recorded data from 26 February to 3 April 2019, and from 10 December 2019 to 14 January 2020. Results We identified eight bat species native to the region as present at CB. Bat activity was related to the proximity of mesic habitats as well as the presence of pine or deciduous forest types, depending on species morphology (i.e., body size, wing-loading, and echolocation call frequency). Activity for all bat species was influenced positively by either time since fire or mean fire return interval. Conclusion Overall, our results suggested that fire use provides a diverse landscape pattern at CB that maintains mesic, deciduous habitat within the larger pine forest matrix, thereby supporting the diverse bat community at CB during the dormant season and early spring.

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