Concrete Frost along an Elevational Gradient in New Hampshire

1975 ◽  
Vol 5 (4) ◽  
pp. 700-705 ◽  
Author(s):  
Timothy J. Fahey ◽  
Gerald E. Lang
Keyword(s):  
Transition Zone ◽  
Leaf Litter ◽  
New Hampshire ◽  
Forest Ecosystems ◽  
Coniferous Forest ◽  
Weather Conditions ◽  
Elevational Gradient ◽  
Forest Types ◽  
Soil Frost ◽  
Sample Points

The occurrence and duration of concrete frost were observed at 28 forested sites along an elevational gradient on a New Hampshire mountain. The presence of concrete frost was determined with an aluminum probe on 17 dates between November 1973 and June 1974. Concrete frost was found at all sample points in soils of coniferous forest ecosystems above 950-m elevation from mid-November to mid-May; some concrete frost remained into early June. Concrete frost occurred at most sample points in soils of transition zone forests that were composed of mixed hardwoods and conifers for 4 months, in soils of northern hardwoods forests for 2 months, and in soils of successional fir stands at low elevations for 4 months. Winter weather conditions and differences in leaf litter insulation probably accounted for the variation of soil frost beneath these forest types.

Fifty years of compositional change in deciduous and coniferous forest types in New Hampshire

1987 ◽  
Vol 17 (5) ◽  
pp. 388-393 ◽  
Author(s):  
William B. Leak
Keyword(s):  
New Hampshire ◽  
Sugar Maple ◽  
Coniferous Forest ◽  
Red Spruce ◽  
Eastern Hemlock ◽  
Forest Types ◽  
American Beech ◽  
Canopy Disturbance ◽  
Bartlett Experimental Forest ◽  
Basal Till

Fifty-year records (52–53 years) from 29 cruise plots on the Bartlett Experimental Forest, New Hampshire, indicated that composition is moving toward a predominance of one or two tolerant species in response to soils (habitat) and, to a lesser extent, elevation. Plots on fine till are moving toward American beech (Fagusgrandifolia Ehrh.) and sugar maple (Acersaccharum Marsh.), with some indication that perpetuation of sugar maple in this region of granitic soils depends upon canopy disturbance. Stands on coarse washed (sandy) till are moving toward beech, with some representation of tolerant conifers. Plots with shallow basal till (well drained to poorly drained), shallow bedrock, or ice-contact gravel are moving toward eastern hemlock (Tsugacanadensis (L.) Carr.) and (or) red spruce (Picearubens Sarg.). Eastern hemlock is successful below elevations of 500–550 m, while red spruce is successful at higher elevations.

scholarly journals Effects of Urban Forest Types and Traits on Soil Organic Carbon Stock in Beijing

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 394
Author(s):  
Xinhui Xu ◽  
Zhenkai Sun ◽  
Zezhou Hao ◽  
Qi Bian ◽  
Kaiyue Wei ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Carbon Stock ◽  
Urban Forest ◽  
Coniferous Forest ◽  
Predictor Variable ◽  
Urban Forests ◽  
Least Squares Regression ◽  
Forest Types ◽  
Organic Carbon Stock

Forests can affect soil organic carbon (SOC) quality and distribution through forest types and traits. However, much less is known about the influence of urban forests on SOC, especially in the effects of different forest types, such as coniferous and broadleaved forests. Our objectives were to assess the effects of urban forest types on the variability of SOC content (SOC concentration (SOCC) and SOC density (SOCD)) and determine the key forest traits influencing SOC. Data from 168 urban forest plots of coniferous or broadleaved forests located in the Beijing urban area were used to predict the effects of forest types and traits on SOC in three different soil layers, 0–10 cm, 10–20 cm, and 20–30 cm. The analysis of variance and multiple comparisons were used to test the differences in SOC between forest types or layers. Partial least squares regression (PLSR) was used to explain the influence of forest traits on SOC and select the significant predictors. Our results showed that in urban forests, the SOCC and SOCD values of the coniferous forest group were both significantly higher than those of the broadleaved group. The SOCC of the surface soil was significantly higher than those of the following two deep layers. In PLSR models, 42.07% of the SOCC variance and 35.83% of the SOCD variance were explained by forest traits. Diameter at breast height was selected as the best predictor variable by comparing variable importance in projection (VIP) scores in the models. The results suggest that forest types and traits could be used as an optional approach to assess the organic carbon stock in urban forest soils. This study found substantial effects of urban forest types and traits on soil organic carbon sequestration, which provides important data support for urban forest planning and management.

scholarly journals Distribution, Morphology, Survival, and Genetics of Aspen (Populus Tremuloides) Seedlings Following the 1988 Yellowstone Fires

1996 ◽  
Vol 20 ◽  
pp. 118-122
Author(s):  
Monica Turner ◽  
Rebecca Reed ◽  
William Romme ◽  
Gerald Tuskan
Keyword(s):  
Populus Tremuloides ◽  
Yellowstone National Park ◽  
National Park ◽  
Plant Competition ◽  
Mineral Soil ◽  
Rare Event ◽  
Weather Conditions ◽  
Elevational Gradient ◽  
Quaking Aspen ◽  
Burned Areas

An unexpected consequence of the 1988 Yellowstone fires was the widespread establishment of seedlings of quaking aspen (Populus tremuloides) in the burned forests, including areas outside the previous range of aspen (Kay 1993; Romme et al. 1997). Although aspen is the most widely distributed tree species in North America (Powells 1965), it is relatively uncommon and localized in distribution within Yellowstone National Park (Despain 1991). Most aspen stands in Yellowstone are found in the lower elevation landscapes in the northern portion of the park, and the species was absent - prior to 1988 -- across most of the high plateaus that dominate the southern and central park area. Aspen in the Rocky Mountain region reproduces primarily by means of vegetative root sprouting. Although viable seeds are regularly produced, establishment of seedlings in the wild is apparently a rare event due to the limited tolerance of aspen seedlings for desiccation or competition (e.g., Pearson 1914; McDonough 1985). In the immediate aftermath of the 1988 Yellowstone fires, there was a brief "window of opportunity" for aspen seedling establishment, as a result of abundant aspen seed production, moist weather conditions in spring and summer, and bare mineral soil and reduced plant competition within extensive burned areas (Jelinski and Cheliak 1992; Romme et al. 1997). We initiated this 3-year study in 1996 to address four questions about the aspen seedlings now growing in burned areas across the Yellowstone Plateau: (1) What are the broad-scale patterns of distribution and abundance of aspen seedlings across the subalpine plateaus of Yellowstone National Park? (2) What is the morphology and population structure -- e.g., proportions of genets (genetic individuals that developed from a single seed) and ramets (vegetative root sprouts produced by a genet) of various ages - in aspen seedling populations? (3) What are the mechanisms leading to eventual persistence or extirpation of seedling populations along an elevational gradient, particularly with respect to ungulate browsing and plant competition? (4) What is the genetic diversity and relatedness of the seedling populations along gradients of elevation and substrate?

scholarly journals Major characteristics of mixed fir and beech virgin forests in the National park Biogradska Gora in Montenegro

2011 ◽  
pp. 157-172 ◽  
Author(s):  
Milic Curovic ◽  
Milan Medarevic ◽  
Rade Cvjeticanin ◽  
Mirko Knezevic
Keyword(s):  
National Park ◽  
Forest Ecosystems ◽  
Structural Characteristics ◽  
Forest Types ◽  
Beech Forests ◽  
Basic Characteristics ◽  
Definition Of ◽  
First Time ◽  
Production Characteristics

In order to manage forest ecosystems at a sufficiently high biodiversity level it is necessary to study the ecological, structural and production characteristics of virgin forests. The research was directed towards identifying the characteristics of mixed fir and beech forests (Abieti-Fagetum s. lat.) in the area of the strict reserve of the National Park Biogradska Gora in Montenegro. Basic characteristics of these forests were researched in the process of definition of forest types. In this manner, it is for the first time that a realistic base for typological management of forests and forest ecosystems with similar ecological and structural characteristics was provided for the specific sites.

Older forests used by northern spotted owls functioned as fire refugia during large wildfires, 1987–2017

2021 ◽  
Author(s):  
Damon B Lesmeister ◽  
Raymond J. Davis ◽  
Stan G. Sovern ◽  
Zhiqiang Yang
Keyword(s):  
Fire Regime ◽  
Fire Severity ◽  
Weather Conditions ◽  
Fire Regimes ◽  
Bimodal Distribution ◽  
Relative Difference ◽  
Positive Trend ◽  
Forest Types ◽  
Spotted Owl ◽  
High Severity

Abstract Background The northern spotted owl (Strix occidentalis caurina) is an Endangered Species Act-listed subspecies that requires forests with old-growth characteristics for nesting. With climate change, large, severe wildfires are expected to be more common and an increasing threat to spotted owl persistence. Understanding fire severity patterns related to nesting forest can be valuable for forest management that supports conservation and recovery, especially if nesting forest functions as fire refugia (i.e., lower fire severity than surrounding landscape). We examined the relationship between fire severity and nesting forests in 472 large wildfires (> 200 ha) that occurred rangewide during 1987–2017. We mapped fire severities (unburned-low, moderate, high) within each fire using relative difference normalized burn ratios and quantified differences in severity between pre-fire nesting forest (edge and interior) and non-nesting forest. We also quantified these relationships within areas of three fire regimes (low severity, very frequent; mixed severity, frequent; high severity, infrequent). Results Averaged over all fires, the interior nesting forest burned at lower severity than edge or non-nesting forest. These relationships were consistent within the low severity, very frequent and mixed severity, frequent fire regime areas. All forest types burned at similar severity within the high severity, infrequent fire regime. During two of the most active wildfire years that also had the largest wildfires occurring in rare and extreme weather conditions, we found a bimodal distribution of fire severity in all forest types. In those years, a higher amount—and proportion—of all forest types burned at high severity. Over the duration of the study, we found a strong positive trend in the proportion of wildfires that burned at high severity in the non-nesting forests, but not in the two nesting forest types. Conclusions Under most wildfire conditions, the microclimate of interior patches of nesting forests likely mitigated fire severity and thus functioned as fire refugia. With changing climates, the future of interior forest as fire refugia is unknown, but trends suggest these older forests can dampen the effect of increased wildfire activity and thus an important component of landscape plans focused on fire resiliency.

scholarly journals Assessing Forest Ecosystems across the Vertical Edge of the Mid-Latitude Ecotone Using the BioGeoChemistry Management Model (BGC-MAN)

Forests ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 523 ◽  
Author(s):  
Cholho Song ◽  
Stephan A. Pietsch ◽  
Moonil Kim ◽  
Sungeun Cha ◽  
Eunbeen Park ◽  
...  
Keyword(s):  
Transition Zone ◽  
Primary Productivity ◽  
Forest Ecosystems ◽  
Net Primary Productivity ◽  
Northeast Asia ◽  
Siberian Larch ◽  
Management Model ◽  
High Mountain ◽  
Specific Information ◽  
Larch Forests

The mid-latitude ecotone (MLE)—a transition zone between boreal and temperate forests, which includes the regions of Northeast Asia around 30°–60° N latitudes—delivers different ecosystem functions depending on different management activities. In this study, we assessed forest volume and net primary productivity changes in the MLE of Northeast Asia under different ecological characteristics, as well as various current management activities, using the BioGeoChemistry Management Model (BGC-MAN). We selected five pilot sites for pine (Scots pine and Korean red pine; Pinus sylvestris and P. densiflora), oak (Quercus spp.), and larch forests (Dahurian larch and Siberian larch; Larix gmelinii and L. sibirica), respectively, which covered the transition zone across the MLE from Lake Baikal, Russia to Kyushu, Japan, including Mongolia, Northeast China, and the Korean Peninsula. With site-specific information, soil characteristics, and management descriptions by forest species, we established their management characteristics as natural preserved forests, degraded forests, sandy and cold forest stands, and forests exposed to fires. We simulated forest volume (m3) and net primary productivity (Mg C ha−1) during 1960–2005 and compared the results with published literature. They were in the range of those specified in previous studies, with some site-levels under or over estimation, but unbiased estimates in their mean values for pine, oak, and larch forests. Annual rates of change in volume and net primary productivity differed by latitude, site conditions, and climatic characteristics. For larch forests, we identified a high mountain ecotype which warrants a separate model parameterization. We detected changes in forest ecosystems, explaining ecological transition in the Northeast Asian MLE. Under the transition, we need to resolve expected problems through appropriate forest management and social efforts.

scholarly journals Boreal coniferous forest density leads to significant variations in soil physical and geochemical properties

2017 ◽  
Vol 14 (14) ◽  
pp. 3445-3459 ◽  
Author(s):  
Carole Bastianelli ◽  
Adam A. Ali ◽  
Julien Beguin ◽  
Yves Bergeron ◽  
Pierre Grondin ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Properties ◽  
Forest Ecosystems ◽  
Coniferous Forest ◽  
Base Cations ◽  
Stand Density ◽  
Environmental Parameters ◽  
Fe Oxides ◽  
Geochemical Properties ◽  
Closed Canopy

Abstract. At the northernmost extent of the managed forest in Quebec, Canada, the boreal forest is currently undergoing an ecological transition between two forest ecosystems. Open lichen woodlands (LW) are spreading southward at the expense of more productive closed-canopy black spruce–moss forests (MF). The objective of this study was to investigate whether soil properties could distinguish MF from LW in the transition zone where both ecosystem types coexist. This study brings out clear evidence that differences in vegetation cover can lead to significant variations in soil physical and geochemical properties.Here, we showed that soil carbon, exchangeable cations, and iron and aluminium crystallinity vary between boreal closed-canopy forests and open lichen woodlands, likely attributed to variations in soil microclimatic conditions. All the soils studied were typical podzolic soil profiles evolved from glacial till deposits that shared a similar texture of the C layer. However, soil humus and the B layer varied in thickness and chemistry between the two forest ecosystems at the pedon scale. Multivariate analyses of variance were used to evaluate how soil properties could help distinguish the two types at the site scale. MF humus (FH horizons horizons composing the O layer) showed significantly higher concentrations of organic carbon and nitrogen and of the main exchangeable base cations (Ca, Mg) than LW soils. The B horizon of LW sites held higher concentrations of total Al and Fe oxides and particularly greater concentrations of inorganic amorphous Fe oxides than MF mineral soils, while showing a thinner B layer. Overall, our results show that MF store three times more organic carbon in their soils (B+FH horizons, roots apart) than LW. We suggest that variations in soil properties between MF and LW are linked to a cascade of events involving the impacts of natural disturbances such as wildfires on forest regeneration that determines the vegetation structure (stand density) and composition (ground cover type) and their subsequent consequences on soil environmental parameters (moisture, radiation rate, redox conditions, etc.). Our data underline significant differences in soil biogeochemistry under different forest ecosystems and reveal the importance of interactions in the soil–vegetation–climate system for the determination of soil composition.

scholarly journals Evaluation of Different Methods for Estimating the Fraction of Sunlit Leaves and Its Contribution for Photochemical Reflectance Index Utilization in a Coniferous Forest

2019 ◽  
Vol 11 (14) ◽  
pp. 1643 ◽  
Author(s):  
Huang ◽  
Qiu ◽  
Fan ◽  
Liu ◽  
Zhang
Keyword(s):  
Coniferous Forest ◽  
Weather Conditions ◽  
Short Time Scale ◽  
Canopy Reflectance ◽  
Climate Conditions ◽  
Photochemical Reflectance Index ◽  
Use Efficiency ◽  
Direct Outcome ◽  
Short Time ◽  
Penumbra Region

Proper determinations of light use efficiency (LUE) and absorbed photosynthetically active radiation (APAR) are essential for LUE models to simulate gross primary productivity (GPP). This study intended to apply the photochemical reflectance index (PRI) to track LUE or APAR variations in a subtropical coniferous forest using tower-based PRI and GPP measurements. To improve the ability of using PRI to track LUE or APAR, a two-leaf approach differentiating sunlit and shaded leaves was used to process the remote sensing and flux data. However, penumbra region, the ‘grey region’ between sunlit and shaded leaves, increases the difficulty for quantifying the fractions of sunlit and shaded leaves. Firstly, three methods with different ways on treating the penumbra region were investigated for estimating the fraction of sunlit leaves (PT). After evaluating the correlations between observed PRI (PRIobs) and inversely retrieved PRI (PRIinv) from estimated PT using the three methods, we found that treating a substantial portion of penumbra region as sunlit leaves was reasonable and using the ratio of canopy reflectance to leaf reflectance as PT was accurate and efficient. Based on this, we used the two-leaf approach to estimate the canopy-level PRI, aiming to evaluate the ability of using PRI as a proxy for LUE or APAR. Results showed that PRI was able to capture half-hourly and daily changes in LUE and APAR, and the two-leaf approach could enhance the correlations between PRI and both LUE and APAR at both half-hourly and daily time steps. Strong diurnal correlations (averaged R = 0.82 from 173 days) between two-leaf PRI and APAR were found on more than 80% days and the relationship between them over the whole study period was also very significant (R2>0.5, p<0.0001) regardless of different climate conditions, suggesting that the two-leaf PRI was probably a better proxy for APAR than for LUE at short-term scale as PRI mainly represented the absorbed energy allocated to photoprotection at short time scale and was a direct outcome driven by APAR. However, the scattered relationships of PRI with LUE and APAR indicated there were still many limitations in usage of PRI to accurately estimate physiological parameters affected by changing weather conditions, pigment pool size, etc., which needed further exploration.

Sign in / Sign up

Export Citation Format

Share Document