scholarly journals Extracellular Soil Enzyme Activities in High-Elevation Mixed Red Spruce Forests in Central Appalachia, U.S.A.

Forests ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 468
Author(s):  
Philip M. Crim ◽  
Jonathan R. Cumming
Keyword(s):  
Tree Species ◽  
The United States ◽  
High Elevation ◽  
N Deposition ◽  
Red Spruce ◽  
Organic Fraction ◽  
Spruce Forests ◽  
Mineral Fraction ◽  
Central Appalachia ◽  
Organic Fractions

Anthropogenic emissions have impacted terrestrial forest ecosystem processes in North America since the industrial revolution. With the passage of the Clean Air Act in 1970 in the United States, atmospheric inputs of nitrogen (N) and sulfur (S) into forests in the Appalachian Mountains have declined, which have, potentially, mitigated their effects on processes such as decomposition and nutrient cycling. Activities of microbial extracellular soil enzymes (ESEs) mediate many rate-limiting nutrient transformations in forest soils and play important roles in the decomposition of complex organic compounds. Soils in high-elevation red spruce forests are characterized by low pH and high carbon (C):N ratios and, having historically received extremely high levels of N deposition, may exhibit legacy impacts of deposition on nutrient availability and decomposition. We utilized four sites along a modeled gradient of N deposition in central Appalachia to assess contemporary ESEs in bulk soil under Acer rubrum L., Betula alleghaniensis Britt., and Picea rubens Sarg. in May, June, and July 2016. Increasing N deposition led to increases in organic fraction C and N and decreases in phosphorus (P). Sites receiving higher N also exhibited greater mineral fraction C, N, and P. ESEs were highest in organic fractions with acid phosphatases (AP) exhibiting the highest activity. There was little influence of N deposition on organic fraction ESEs, but strong evidence for a positive relationship between N deposition and activities of AP, β-glucosidases (BG), and chitinase (NAG) in mineral fractions. Species effects on ESEs were present with high AP in organic fractions under spruce and high mineral fraction fungal laccase (LAC) under birch. The sampling season demonstrated little effect on ESEs. ESEs were more strongly influenced by plot-level factors, such as tree species diversity and abundance of ectomycorrhizal (ECM) tree species, than temporal or soil factors or nutrient status related to modeled cumulative N deposition across these sites. Decreases in AP, BG, and NAG activities with greater abundance of broadleaf deciduous species and increases in activities with ECM host abundance indicate that microbial communities driven by these plant functional groups are responsible for the differences in ESEs observed in these high-elevation mixed red spruce stands.

scholarly journals Soil and Tree Nutrient Status of High Elevation Mixed Red Spruce (Picea rubens Sarg.) and Broadleaf Deciduous Forests

Soil Systems ◽  
2019 ◽  
Vol 3 (4) ◽  
pp. 80 ◽  
Author(s):  
Philip M. Crim ◽  
Louis M. McDonald ◽  
Jonathan R. Cumming
Keyword(s):  
Tree Species ◽  
The United States ◽  
High Elevation ◽  
N Deposition ◽  
Picea Rubens ◽  
Red Spruce ◽  
Betula Alleghaniensis ◽  
Industrial Emissions ◽  
Mixed Stands ◽  
Soil Fractions

Anthropogenic and industrial emissions have resulted in historically high levels of acidic deposition into central Appalachian forests. Despite the reduction in acidic inputs due to legislation curbing industrial emissions in the United States, continued N deposition may impact forest ecosystems. Soil and foliar samples were collected from four high elevation red spruce sites along a modeled gradient of historic N deposition. The three most abundant tree species at all sites, Acer rubrum L., Betula alleghaniensis Britt., and Picea rubens Sarg., were sampled. Bulk soil beneath the canopies of individual trees were collected from the top 15-cm and separated into organic and mineral fractions for analysis. Mehlich-III soil extracts of soil fractions and foliar digests from these trees were subjected to elemental analysis. Soil N concentrations supported the presence of a N deposition gradient: in organic horizon soil fractions, N concentrations were driven by precipitation volume and elevation; whereas in mineral soil fractions, N concentration was explained by modeled N deposition rate and elevation. In organic fractions, significant reductions in Ca, K, and P were evident as N deposition increased, whereas the Ca:Sr ratio increased. Foliar Ca, K, and Sr declined in foliage with increasing N deposition, with concomitant increases in foliar Ca:Sr ratios. Although the three species were sympatric in mixed stands at all four sites, the foliar–soil nutrient associations differed among them across the gradient, indicating differential uptake and cycling of nutrients/metals by these forest tree species.

Copper Partitioning Among Mineral and Organic Fractions in Biosolids

2006 ◽  
Vol 3 (1) ◽  
pp. 48 ◽  
Author(s):  
I. W. Oliver ◽  
G. Merrington ◽  
M. J. McLaughlin
Keyword(s):  
Organic Matter ◽  
Sorption Capacity ◽  
Large Degree ◽  
Land Application ◽  
Organic Fraction ◽  
Potential Threat ◽  
Mineral Fraction ◽  
Organic Fractions ◽  
Over Time

Environmental Context.Only a portion of the total amount of heavy metals present in sewage biosolids is accessible to organisms, including plants, and therefore only that portion presents any possible toxicity threat. However, metals such as copper, which are commonly associated to a large degree with the organic fraction, may become more accessible over time as organic components degrade. Determining the extent of partitioning of Cu between the organic and inorganic fractions may provide an indication of any long-term risks associated with utilisation of biosolids in agriculture. Abstract.Metal partitioning between organic and mineral fractions in biosolids may provide an indication of the long-term risks associated with land application of the material. For example, metals found to partition into the organic phase may pose a potential threat when the organic matter is decomposed, whereas metals bound in the mineral fraction would be expected to remain stable over time (given no changes in other environmental conditions) owing to the stability of mineral components. Therefore the question of which components bind copper in biosolids, and whether the sorption capacity is maintained over time, was addressed in the present study. Biosolids incubated for 21 months and non-incubated controls were examined. The solid–solution distribution coefficient (Kd) for Cu was measured in whole biosolids and in biosolid organic and mineral fractions via batch experiments employing the radioactive isotope 64Cu. The mineral fraction was isolated by NaOCl oxidation, whereas the organic fraction was isolated using HF. Results found the relative importance of mineral and organic fractions to Cu sorption varies between biosolids, and in some cases can vary over time. Reduction in sorption capacity caused by losses of organic matter in some biosolids suggests the possibility of increased availability of biosolid metals over time.

Site-level importance of broadleaf deciduous trees outweighs the legacy of high nitrogen (N) deposition on ecosystem N status of Central Appalachian red spruce forests

2016 ◽  
Vol 408 (1-2) ◽  
pp. 343-356 ◽  
Author(s):  
Kenneth R. Smith ◽  
Justin M. Mathias ◽  
Brenden E. McNeil ◽  
William T. Peterjohn ◽  
Richard B. Thomas
Keyword(s):  
N Deposition ◽  
Red Spruce ◽  
Deciduous Trees ◽  
High Nitrogen ◽  
Spruce Forests ◽  
N Status

Actual organization of forest communities with broad-leaved trees in broad-leaved-coniferous zone (with Moscow Region as an example)

2018 ◽  
pp. 107-130 ◽  
Author(s):  
T. V. Chernenkova ◽  
O. V. Morozova ◽  
N. G. Belyaeva ◽  
M. Yu. Puzachenko
Keyword(s):  
Tree Species ◽  
Forest Cover ◽  
Activity Index ◽  
Plant Cover ◽  
Moscow Region ◽  
Pine Forests ◽  
Coniferous Forests ◽  
Oak Forests ◽  
Study Region ◽  
Spruce Forests

This study aimed at an investigation of the structure, ecology and mapping of mixed communities with the participation of spruce, pine and broad-leave trees in one of the regions of broad-leave–coniferous zone. Despite the long history of the nature use of the study area, including forestry practices (Kurnayev, 1968; Rysin, Saveliyeva, 2007; Arkhipova, 2014; Belyaeva, Popov, 2016), the communities kept the main features of the indigenous forests of the broad-leave–coniferous zone ­— the tree species polydominance of the stands, the multilayer structure of communities and the high species diversity. In the course of field works in the southwestern part of the Moscow Region (2000–2016) 120 relevés were made. Spatial structure, species composition as well as cover values (%) of all vascular plants and bryophytes were recorded in each stand. The relevés were analysed following the ecology-phytocenotic classification approach and methods of multivariate statistical analysis that allowed correctly to differentiate communities according the broad-leave species participation. The accuracy of the classification based on the results of discriminant analysis was 95.8 %. Evaluation of the similarity of the selected units was carried out with the help of cluster analysis (Fig. 12). Clustering into groups is performed according to the activity index of species (A) (Malyshev, 1973) within the allocated syntaxon using Euclidean distance and Ward’s method. The classification results are corrected by DCA ordination in PC-ORD 5.0 (McCune, Mefford, 2006) (Fig. 1). Spatial mapping of forest cover was carried out on the basis of ground data, Landsat satellite images (Landsat 5 TM, 7 ETM +, 8 OLI_TIRS), digital elevation (DEM) and statistical methods (Puzachenko et al., 2014; Chernenkova et al., 2015) (Fig. 13 а, б). The obtained data and the developed classification refine the existing understanding of the phytocenotic structure of the forest cover of the broad-leave–coniferous zone. Three forest formation groups with different shares of broad-leave species in the canopy with seven groups of associations were described: a) coniferous forests with broad-leave species (small- and broad-herb spruce forests with oak and lime (1)); broad-herb spruce forests with oak and lime (2); small- and broad-herb pine forests with spruce, lime, oak and hazel (3); broad-herb pine forests with lime, oak and hazel (4)), b) broad-leave–coniferous forests (broad-herb spruce–broad-leave forests (5)), and c) broad-leave forests (broad-herb oak forests (6), broad-herb lime forests (7)). In the row of discussed syntaxa from 1 to 7 group, the change in the ratio of coniferous and broad-leave species of the tree layer (A) reflects re­gular decrease in the participation of spruce in the plant cover (from 66 to 6 %; Fig. 3 A1, A2) and an increase in oak and lime more than threefold (from 15 to 65 %; Fig. 4 a). Nemoral species predominate in the composition of ground layers, the cove­rage of which increases (from 40 to 80 %) in the range from 1 to 7 group, the coverage of the boreal group varies from 55 to 8 % (Fig. 11) while maintaining the presence of these species, even in nemoral lime and oak forests. In forests with equal share of broad-leave and coniferous trees (group 5) the nemoral species predominate in herb layer. In oak forests (group 6) the species of the nitro group are maximally represented, which is natural for oak forests occurring on rich soils, and also having abundant undergrowth of hazel. Practically in all studied groups the presence of both coniferous (in particular, spruce) and broad-leave trees in undergrowth (B) and ground layer (C) were present in equal proportions (Fig. 3). This does not confirm the unambiguity of the enrichment with nemoral species and increase in their cover in complex spruce and pine forests in connection with the climate warming in this region, but rather indicates on natural change of the main tree species in the cenopopulations. Further development of the stand and the formation of coni­ferous or broad-leave communities is conditioned by landscape. It is proved that the distribution of different types of communities is statistically significant due to the relief. According to the results of the analysis of remote information, the distribution areas of coniferous forests with broad-leave species, mixed and broad-leave forest areas for the study region are represented equally. The largest massifs of broad-leave–coniferous forests are located in the central and western parts of the study area, while in the eastern one the broad-leave forests predominate, that is a confirmation of the zonal ecotone (along the Pakhra River: Petrov, Kuzenkova, 1968) from broad-leave–coniferous forests to broad-leave forests.

scholarly journals Dating of Cremated Bones

Radiocarbon ◽  
2001 ◽  
Vol 43 (2A) ◽  
pp. 249-254 ◽  
Author(s):  
J N Lanting ◽  
A T Aerts-Bijma ◽  
J van der Plicht
Keyword(s):  
Mass Spectrometry ◽  
Success Rate ◽  
Accelerator Mass Spectrometry ◽  
Bone Collagen ◽  
Organic Fraction ◽  
Mineral Fraction

When dating unburnt bone, bone collagen, the organic fraction of the bone, is used. Collagen does not survive the heat of the cremation pyre, so dating of cremated bone has been considered impossible. Structural carbonate in the mineral fraction of the bone, however, survives the cremation process. We developed a method of dating cremated bone by accelerator mass spectrometry (AMS), using this carbonate fraction. Here we present results for a variety of prehistoric sites and ages, showing a remarkable success rate for this method.

Effects of nitrogen deposition on nitrate leaching from forests of the northeastern United States will change with tree species composition

2017 ◽  
Vol 47 (8) ◽  
pp. 997-1009 ◽  
Author(s):  
Katherine F. Crowley ◽  
Gary M. Lovett
Keyword(s):  
United States ◽  
Species Composition ◽  
Nitrate Leaching ◽  
Tree Species ◽  
N Deposition ◽  
Red Oak ◽  
Northeastern United States ◽  
Tree Species Composition ◽  
White Ash ◽  
Species Change

As tree species composition in forests of the northeastern United States changes due to invasive forest pests, climate change, or other stressors, the extent to which forests will retain or release N from atmospheric deposition remains uncertain. We used a species-specific, dynamic forest ecosystem model (Spe-CN) to investigate how nitrate (NO3–) leaching may vary among stands dominated by different species, receiving varied atmospheric N inputs, or undergoing species change due to an invasive forest pest (emerald ash borer; EAB). In model simulations, NO3– leaching varied widely among stands dominated by 12 northeastern North American tree species. Nitrate leaching increased with N deposition or forest age, generally with greater magnitude for deciduous (except red oak) than coniferous species. Species with lowest baseline leaching rates (e.g., red spruce, eastern hemlock, red oak) showed threshold responses to N deposition. EAB effects on leaching depended on the species replacing white ash: after 100 years, predicted leaching increased 73% if sugar maple replaced ash but decreased 55% if red oak replaced ash. This analysis suggests that the effects of tree species change on NO3– leaching over time may be large and variable and should be incorporated into predictions of effects of N deposition on leaching from forested landscapes.

Tekstura drzewostanów naturalnych w polskich parkach narodowych na tle teorii dynamiki lasu

2021 ◽  
Author(s):  
Leszek Bartkowicz ◽  
Keyword(s):  
Tree Species ◽  
Stand Structure ◽  
Basal Area ◽  
Site Conditions ◽  
Gap Dynamics ◽  
Old Growth ◽  
Mosaic Pattern ◽  
Spruce Forests ◽  
Old Growth Forest ◽  
Patch Mosaic

The aim of the study was to compare a patch-mosaic pattern in the old-growth forest stands developed in various climate and soil conditions occurring in different regions of Poland. Based on the assumption, that the patch-mosaic pattern in the forest reflect the dynamic processes taking place in it, and that each type of forest ecosystem is characterized by a specific regime of natural disturbances, the following hypotheses were formulated: (i) the patches with a complex structure in stands composed of latesuccessional, shade-tolerant tree species are more common than those composed of early-successional, light-demanding ones, (ii) the patch-mosaic pattern is more heterogeneous in optimal forest site conditions than in extreme ones, (iii) in similar site conditions differentiation of the stand structure in distinguished patches is determined by the successional status of the tree species forming a given patch, (iv) the successional trends leading to changes of species composition foster diversification of the patch structure, (v) differentiation of the stand structure is negatively related to their local basal area, especially in patches with a high level of its accumulation. Among the best-preserved old-growth forest remaining under strict protection in the Polish national parks, nineteen research plots of around 10 ha each were selected. In each plot, a grid (50 × 50 m) of circular sample subplots (with radius 12,62 m) was established. In the sample subplots, species and diameter at breast height of living trees (dbh ≥ 7 cm) were determined. Subsequently, for each sample subplot, several numerical indices were calculated: local basal area (G), dbh structure differentiation index (STR), climax index (CL) and successional index (MS). Statistical tests of Kruskal- Wallis, Levene and Generalized Additive Models (GAM) were used to verify the hypotheses. All examined forests were characterized by a large diversity of stand structure. A particularly high frequency of highly differentiated patches (STR > 0,6) was recorded in the alder swamp forest. The patch mosaic in the examined plots was different – apart from the stands with a strongly pronounced mosaic character (especially subalpine spruce forests), there were also stands with high spatial homogeneity (mainly fir forests). The stand structure in the distinguished patches was generally poorly related to the other studied features. Consequently, all hypotheses were rejected. These results indicate a very complex, mixed pattern of forest natural dynamics regardless of site conditions. In beech forests and lowland multi-species deciduous forests, small-scale disturbances of the gap dynamics type dominate, which are overlapped with less frequent medium-scale disturbances. In more difficult site conditions, large-scale catastrophic disturbances, which occasionally appear in communities formed under the influence of gap dynamics (mainly spruce forests) or cohort dynamics (mainly pine forests), gain importance.

Physical, chemical, and mineralogical attributes and organic fractions of biogenic aggregates of earthworms and toposequence of Inceptisol in semi-arid region

2021 ◽  
Vol 45 ◽  
Author(s):  
Eula Paula da Silva Santos ◽  
Flavia Giglianne Freitas Lima ◽  
Eulene Francisco da Silva ◽  
Diana Ferreira de Freitas ◽  
Eveline de Almeida Ferreira ◽  
...  
Keyword(s):  
Clay Minerals ◽  
Arid Region ◽  
Organic Fraction ◽  
Neem Tree ◽  
Physical Chemical ◽  
Organic Fractions ◽  
Semi Arid Region ◽  
Lower Slope ◽  
Semi Arid ◽  
Properties Of Soil

ABSTRACT Earthworms are known to improve soil fertility by altering the physicochemical properties of soil. However, the changes in properties of biogenic aggregates (produced by earthworms) in regions with different vegetation covers and soils of Inceptisol toposequence in the semi-arid region have not been studied. The objective of this work was to determine the variations of the physical, chemical, and mineralogical attributes and organic fractions of biogenic aggregates of earthworms under different vegetation covers and compare them to an Inceptisol toposequence in the semi-arid region of Pernambuco State, Brazil. For this study, four Inceptisol soil profiles were selected. The sampled points were P1-upper; P2-middle third; P3-middle third; and P4-lower slope, and the soils were collected at a depth of 0-0.20 m. The biogenic aggregates were found in the P3 samples collected from three areas with different vegetation covers: an area with mesquite tree vegetation (Prosopis juliflora [Sw] D.C.); an area with neem tree vegetation (Azadirachta indica A. Juss); and an area with forage palm and mesquite tree vegetation (Opuntia sp. and Nopalea sp.). Results indicate that the biogenic aggregates were in the form of irregular blocks with a size greater than 40 mm. As compared to Inceptisol samples, these aggregates tended to select particles of smaller diameter and exhibited higher concentrations of clay minerals. The chemical and organic fraction analysis revealed that the aggregates exhibited higher Ca2+, total organic carbon (TOC), labile and humic substances, regardless of the vegetation cover. The mineralogical analysis revealed that the action of earthworms did not change the quantity or type of clay minerals.

Sign in / Sign up

Export Citation Format

Share Document