scholarly journals Variation in Downed Deadwood Density, Biomass, and Moisture during Decomposition in a Natural Temperate Forest

Forests ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1352
Author(s):  
Tomáš Přívětivý ◽  
Pavel Šamonil
Keyword(s):  
Decomposition Rate ◽  
Abies Alba ◽  
Exponential Model ◽  
Rate Of Change ◽  
Time Since Death ◽  
Forest Reserves ◽  
Geochemical Models ◽  
Decomposition Pathway ◽  
Species Specific ◽  
Management Recommendations

Deadwood is a resource of water, nutrients, and carbon, as well as an important driving factor of spatial pedocomplexity and hillslope processes in forested landscapes. The applicability of existing relevant studies in mountain forests in Central Europe is limited by the low number of data, absence of precise dating, and short time periods studied. Here, we aimed to assess the decomposition pathway in terms of changes and variability in the physical characteristics of deadwood (wood density, biomass, and moisture) during the decomposition process, and to describe differences in decomposition rate. The research was carried out in the Žofínský Primeval Forest, one of the oldest forest reserves in Europe. Samples were taken from sapwood of downed logs of the three main tree species: Fagus sylvatica L., Abies alba Mill., and Picea abies (L.) Karst. The time since the death of each downed log was obtained using tree censuses repeated since 1975 and dendrochronology. The maximal time since the death of a log was species-specific, and ranged from 61–76 years. The rate of change (slope) of moisture content along the time since death in a linear regression model was the highest for F. sylvatica (b = 3.94) compared to A. alba (b = 2.21) and P. abies (b = 1.93). An exponential model showing the dependence of biomass loss on time since death revealed that F. sylvatica stems with a diameter of 50–90 cm had the shortest decomposition rate—51 years—followed by P. abies (71 years) and A. alba (72 years). Our findings can be used in geochemical models of element cycles in temperate old-growth forests, the prediction of deadwood dynamics and changes in related biodiversity, and in refining management recommendations.

scholarly journals Time since death and decay rate constants of Norway spruce and European larch deadwood in subalpine forests determined using dendrochronology and radiocarbon dating

2015 ◽  
Vol 12 (17) ◽  
pp. 14797-14832 ◽  
Author(s):  
M. Petrillo ◽  
P. Cherubini ◽  
G. Fravolini ◽  
J. Ascher ◽  
M. Schärer ◽  
...  
Keyword(s):  
Decay Rate ◽  
Tree Rings ◽  
Rate Constants ◽  
Radiocarbon Dating ◽  
Woody Debris ◽  
Visual Assessment ◽  
Exponential Model ◽  
Alpine Valley ◽  
Species Specific ◽  
Negative Exponential

Abstract. Due to the large size and highly heterogeneous spatial distribution of deadwood, the time scales involved in the coarse woody debris (CWD) decay of Picea abies (L.) Karst. and Larix decidua Mill. in Alpine forests have been poorly investigated and are largely unknown. We investigated the CWD decay dynamics in an Alpine valley in Italy using the five-decay class system commonly employed for forest surveys, based on a macromorphological and visual assessment. For the decay classes 1 to 3, most of the dendrochronological samples were cross-dated to assess the time that had elapsed since tree death, but for decay classes 4 and 5 (poorly preserved tree rings) and some others not having enough tree rings, radiocarbon dating was used. In addition, density, cellulose and lignin data were measured for the dated CWD. The decay rate constants for spruce and larch were estimated on the basis of the density loss using a single negative exponential model. In the decay classes 1 to 3, the ages of the CWD were similar varying between 1 and 54 years for spruce and 3 and 40 years for larch with no significant differences between the classes; classes 1–3 are therefore not indicative for deadwood age. We found, however, distinct tree species-specific differences in decay classes 4 and 5, with larch CWD reaching an average age of 210 years in class 5 and spruce only 77 years. The mean CWD rate constants were 0.012 to 0.018 yr−1 for spruce and 0.005 to 0.012 yr−1 for larch. Cellulose and lignin time trends half-lives (using a multiple-exponential model) could be derived on the basis of the ages of the CWD. The half-lives for cellulose were 21 yr for spruce and 50 yr for larch. The half-life of lignin is considerably higher and may be more than 100 years in larch CWD.

Decomposition of stumps 10 years after partial and complete harvesting in a southern boreal forest in Finland

2008 ◽  
Vol 38 (9) ◽  
pp. 2414-2421 ◽  
Author(s):  
Ekaterina Shorohova ◽  
Ekaterina Kapitsa ◽  
Ilkka Vanha-Majamaa
Keyword(s):  
Decomposition Rate ◽  
Rate Constants ◽  
Meta Analysis ◽  
Exponential Model ◽  
Published Data ◽  
Birch Bark ◽  
Spruce Bark ◽  
Betula Pubescens Ehrh ◽  
Opposite Tendency

We studied the decomposition of cut stumps of Norway spruce ( Picea abies (L.) Karst.), Scots pine ( Pinus sylvestris L.), and birches ( Betula pubescens Ehrh. and Betula pendula Roth.) 10 years after clear felling, low level retention felling, gap felling, and selection felling. Bulk density of wood, mass per surface area of bark, and mass of wood and bark for entire stumps were estimated. Using a single exponential model, annual decomposition rate constants (k) were calculated as 0.071, 0.052, and 0.041 ·year–1 for birch, spruce, and pine, respectively. The k values for wood decreased in the same order. For bark, the order was different: spruce bark decomposed slower than pine bark. Fragmentation accelerated mass loss. Pine and birch bark decomposed faster than pine and birch wood, whereas spruce showed the opposite tendency. The wood density and bark mass did not depend on retention levels. Diameter of stumps did not explain variation in decomposition either. The high importance of stumps for biodiversity, carbon, and nutrient cycling requires refinements to decomposition rate constants. Thus, further research based on new empirical data and meta-analysis of published data is needed to reveal factors influencing the decomposition process in situ.

scholarly journals Characterization of the interactive effects of labile and recalcitrant organic matter on microbial growth and metabolism

2019 ◽  
Author(s):  
Lauren N. M. Quigley ◽  
Abigail Edwards ◽  
Andrew D. Steen ◽  
Alison Buchan
Keyword(s):  
Organic Matter ◽  
Marine Bacteria ◽  
Interactive Effects ◽  
Specific Substrate ◽  
Growth Responses ◽  
Metabolic Potential ◽  
Labile Organic Matter ◽  
Casamino Acids ◽  
Geochemical Models ◽  
Species Specific

AbstractGeochemical models typically represent organic matter (OM) as consisting of multiple, independent pools of compounds, each accessed by microorganisms at different rates. However, recent findings indicate that organic compounds can interact within microbial metabolisms. The relevance of interactive effects within marine systems is debated and a mechanistic understanding of its complexities, including microbe-substrate relationships, is lacking. As a first step toward uncovering mediating processes, the interactive effects of distinct pools of OM on the growth and respiration of marine bacteria, individual strains and a simple, constructed community of Roseobacter lineage members were tested. Isolates were provided with natural organic matter (NOM) and different concentrations (1, 4, 40, 400 μM-C) and forms of labile organic matter (acetate, casamino acids, tryptone, coumarate). The microbial response to the mixed substrate regimes was assessed using viable counts and respiration in two separate experiments. Two marine bacteria and a six-member constructed community were assayed with these experiments. Both synergistic and antagonistic growth responses were evident for all strains, but all were transient. The specific substrate conditions promoting a response, and the direction of that response, varied amongst species. These findings indicate that the substrate conditions that result in OM interactive effects are both transient and species-specific and thus influenced by both the composition and metabolic potential of a microbial community.

scholarly journals Effects of drought on nitrogen uptake and carbon dynamics in trees

2020 ◽  
Author(s):  
Jobin Joseph ◽  
Jörg Luster ◽  
Alessandra Bottero ◽  
Nathalie Buser ◽  
Lukas Baechli ◽  
...  
Keyword(s):  
Fine Roots ◽  
Carbon Allocation ◽  
N Uptake ◽  
Abies Alba ◽  
Quercus Petraea ◽  
N Availability ◽  
Uptake Capacity ◽  
Effects Of Drought ◽  
Species Specific

Abstract Research on drought impact on tree functioning is focused primarily on water and carbon (C) dynamics. Changes in nutrient uptake might also affect tree performance under drought and there is a need to explore underlying mechanisms. We investigated effects of drought on a) in-situ nitrogen (N)-uptake accounting for both, N availability to fine-roots in soil and actual N-uptake, b) physiological N-uptake capacity of roots, and c) the availability of new assimilates to fine roots influencing the N-uptake capacity using 15N and 13C labelling. We assessed saplings of six different tree species (Acer peudoplatanus, Fagus sylvatica, Quercus petraea, Abies alba, Picea abies, Pinus sylvestris). Drought resulted in significant reduction of in-situ soil N-uptake in deciduous trees accompanied by reduced carbon allocation to roots and by a reduction in root biomass available for N-uptake. While physiological root N-uptake capacity was not affected by drought in deciduous saplings, reduced maximum ammonium but not nitrate uptake was observed for A.alba and P.abies. Our results indicate that drought has species-specific effects on N-uptake. Even water limitations of only 5 weeks as assessed here can decrease whole plant inorganic N-uptake independent of whether the physiological N-uptake capacity is affected or not.

scholarly journals Influence of Warmer and Drier Environmental Conditions on Species-Specific Stem Circumference Dynamics and Water Status of Conifers in Submontane Zone of Central Slovakia

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2945
Author(s):  
Adriana Leštianska ◽  
Peter Fleischer ◽  
Katarína Merganičová ◽  
Peter Fleischer ◽  
Katarína Střelcová
Keyword(s):  
Water Deficit ◽  
Environmental Conditions ◽  
Water Status ◽  
Abies Alba ◽  
Growth Patterns ◽  
Forest Growth ◽  
Mature Trees ◽  
Natural Habitats ◽  
Band Dendrometers ◽  
Species Specific

The frequency and intensity of droughts and heatwaves in Europe with notable impact on forest growth are expected to increase due to climate change. Coniferous stands planted outside the natural habitats of species belong to the most threatened forests. In this study, we assess stem circumference response of coniferous species (Larix decidua and Abies alba) to environmental conditions during the years 2015–2019. The study was performed in Arboretum in Zvolen (ca. 300 m a.s.l., Central Slovakia) characterised by a warmer and drier climate when compared to their natural habitats (located above 900 m a.s.l.), where they originated from. Seasonal radial variation, tree water deficit (ΔW), and maximum daily shrinkage (MDS) were derived from the records obtained from band dendrometers installed on five mature trees per species. Monitored species exhibited remarkably different growth patterns under highly above normal temperatures and uneven precipitation distribution. The magnitudes of reversible circumference changes (ΔW, MDS) were species-specific and strongly correlated with environmental factors. The wavelet analysis identified species-specific vulnerability to drought indicated by pronounced diurnal stem variation periodicity in rainless periods. L. decidua exhibited more strained stem water status and higher sensitivity to environmental conditions than A. alba. Tree water deficit and maximum daily shrinkage were found appropriate characteristics to compare water status of different tree species.

Tree rings used to assess time since death of deadwood of different decay classes in beech and silver fir forests in the central Apennines (Molise, Italy)

2008 ◽  
Vol 38 (4) ◽  
pp. 821-833 ◽  
Author(s):  
Fabio Lombardi ◽  
Paolo Cherubini ◽  
Bruno Lasserre ◽  
Roberto Tognetti ◽  
Marco Marchetti
Keyword(s):  
Ring Width ◽  
Morphological Characteristics ◽  
Abies Alba ◽  
Decay Rates ◽  
Silver Fir ◽  
Time Since Death ◽  
Forest Stands ◽  
Decomposition Rates ◽  
Central Apennines ◽  
The Relationship

We investigated the relationship between time since death and morphological characteristics of Abies alba Mill. (European silver fir) and Fagus sylvatica L. (European beech) stumps in two forest stands in the central Apennines. At each site, 15 or 16 living trees were selected, and increment cores were collected to build master ring-width chronologies. For both sites, cross sections were collected from stumps. Samples were assigned to visually discernible decay classes, and their death date dendrochronologically determined. Using cross-dating techniques, stumps cross-dated significantly with standard chronologies, and it was possible to assign a year of death to 77% and 69% of sampled A. alba and F. sylvatica stumps, respectively. Analysis of the time since death of the stumps suggests that the two species have similar decay rates, although A. alba was faster in passing from class 2 to class 3. However, this study revealed a continuum through decay classes and showed a high variability in the transition rate from one class to another. Overall, information obtained using dendrochronological techniques was valuable for assessing deadwood decomposition rates. The variability found in stump decomposition rates indicates that existing decay classification schemes, although providing information on decomposition timing, are hardly applicable to these forest stands and that the relationship between qualitatively assessed decay classes and time since death of trees appears to be rather weak.

scholarly journals Determination of the stability of osmium(IV) hexachloride ICP-OES standards in HCl acid matrix

2020 ◽  
Vol 34 (1) ◽  
pp. 193-202
Author(s):  
Trevor T. Chiweshe ◽  
Abdon Atangana ◽  
Lore-Mari Deysel
Keyword(s):  
Mathematical Models ◽  
Acid Concentration ◽  
Decomposition Rate ◽  
Room Temperature ◽  
Stochastic Approach ◽  
Rate Of Change ◽  
Icp Oes ◽  
Local Operators ◽  
Non Local ◽  
Stock Solutions

The ideal HCl concentration used in stabilizing osmium standards was investigated in this study. Additionally, mathematical models were tested to predict the decomposition rate of osmium standards at room temperature. Osmium(IV) hexachloride stock solutions stabilized in 7 and 15% HCl were used to assess the decomposition rate using ICP-OES. Several sets of calibration standards were prepared from the original stock solutions. The first calibration set was prepared with no additional HCl added to the final solutions and other sets with a total HCl acid concentration of 0.2, 0.4, 0.6, 1.0 and 1.5% v/v. Emission intensities were measured at 0, 24, 48, 72 and 96 hours. Standards with no additional HCl acid added kept at room temperature showed increase in emission intensities after 24 hours. These changes in emission intensities indicated chemical instability of osmium standards at low acid concentration levels. Standards stabilized in 1.0–1.5% HCl and refrigerated below 10 ⁰C showed consistent emission intensities and had a shelf life of up to 48 and 72 hours, respectively.  Four mathematical models were tested to determine the decomposition rate of the osmium standard. The first used rate of change concept and the second a stochastic approach. Both failed to capture osmium decay. The third was based on non-local operators with power law kernel and was able to capture the decay at earlier, but not later stages. The fourth, based on non-local operators with non-singular kernel was able to capture earlier and later decay due to its crossover properties in waiting time distribution.   Bull. Chem. Soc. Ethiop. 2020, 34(1), 193-202. DOI: https://dx.doi.org/10.4314/bcse.v34i1.18

scholarly journals Florida Homeowner Herbicide Guide: Considerations, Applications, and Selection

EDIS ◽  
2019 ◽  
Vol 2019 (4) ◽  
pp. 9
Author(s):  
Chris Marble
Keyword(s):  
Weed Control ◽  
Pest Control ◽  
Retail Stores ◽  
Weed Species ◽  
General Management ◽  
Identification Guide ◽  
Species Specific ◽  
Management Recommendations ◽  
Lawn Maintenance

While some people opt for professional lawn maintenance companies, some homeowners may wish to perform their own landscape pest control in order to save money, to have more control of what is applied, or simply because they enjoy it. This EDIS publication is for Florida gardeners, horticulturalists and homeowners who want to utilize herbicides to control weeds in their landscape. This publication discusses common herbicides available at retail stores and how homeowners can use these them safely and effectively.https://edis.ifas.ufl.edu/ep575 This publication provides information and general management recommendations for a variety of common weed species found throughout Florida. For a species-specific weed identification guide or information on weed control in turfgrass, visit the EDIS Weed Control directory.

scholarly journals Beziehungen zwischen Baum- und Krautschicht in Buchenmischwäldern | Relations between tree and herb layer in mixed beech forests

2010 ◽  
Vol 161 (4) ◽  
pp. 147-156 ◽  
Author(s):  
Judith Reusser ◽  
Caroline Heiri ◽  
Pascale Weber ◽  
Harald Bugmann
Keyword(s):  
Light Availability ◽  
Herb Layer ◽  
Forest Reserves ◽  
Site Characteristics ◽  
Tree Layer ◽  
Negative Effect ◽  
Study Sites ◽  
The Stability ◽  
Species Specific ◽  
Layer Composition

Tree layer composition is a crucial factor for the stability and diversity of forest ecosystems, and many factors such as nutrient availability or the light regime are influenced by trees and their species-specific properties. The occurrence and abundance of herbs as indicators for site characteristics are likely to be related to the variability in tree layer diversity and changes in environmental variables. To test this hypothesis, the effect of tree layer composition on herb layer diversity was studied in mixed deciduous beech (Fagus sylvatica) forest reserves on the Swiss Plateau. Applying a transect design we recorded tree and herbaceous species composition and measured key top soil properties and light availability in seven forest reserves. Tree layer diversity did not affect herb layer diversity at the study sites. However, a species-specific influence of trees on the herb layer was evident: a high proportion of beech had a negative effect on herb layer diversity, and the presence of ash (Fraxinus excelsior) was correlated with a thick A h horizon and high soil pH, which enhanced herb layer diversity. Spruce (Picea abies) and pine (Pinus sylvestris) were related to a thick forest floor (litter) layer, which negatively affected herb layer diversity.

scholarly journals Decomposition of Arachis pintoi and Hyparrhenia rufa litters in monoculture and intercropped systems under lowland soil

2003 ◽  
Vol 38 (9) ◽  
pp. 1089-1095 ◽  
Author(s):  
Christiane Abreu de Oliveira ◽  
Maria Rita Scotti Muzzi ◽  
Hortênsia Abrantes Purcino ◽  
Ivanildo Evódio Marriel ◽  
Nadja Maria Horta de Sá
Keyword(s):  
Decomposition Rate ◽  
Nutrient Recycling ◽  
Exponential Model ◽  
Wet Season ◽  
Litter Bags ◽  
Arachis Pintoi ◽  
Tropical Grasslands ◽  
Hyparrhenia Rufa ◽  
Number Of Microorganisms ◽  
Degraded Pastures

Tropical grasslands under lowland soils are generally underutilized and the litter of forage legumes may be used to recover these degraded pastures. The objective of this work was to study the dynamics of litter decomposition of Arachis pintoi (pinto peanut), Hyparrhenia rufa (thatching grass) and a mixture of both species in a lowland soil. These treatments were analyzed in three areas: grass monoculture, legume monoculture and legume intercropped with the grass during the dry and wet seasons. Litter bags containing the legume, grass or a mixture of both species were incubated to estimate the decomposition rate and microorganism colonization. Decomposition constants (K) and litter half-lives (T1/2) were estimated by an exponential model whereas number of microorganisms in specific media were determined by plate dilution. The decomposition rate, release of nutrients and microorganisms number, especially bacteria, increased when pinto peanut was added to thatching grass, influenced by favorable lignin/N and C/N ratios in legume litter. When pinto peanut litter was incubated in the grass plots, 50% N and P was released within about 135 days in the dry season and in the wet season, the equivalent release occurred within 20 days. These results indicate that A. pintoi has a great potential for nutrient recycling via litter and can be used to recover degraded areas.

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