Pedological memory in the evolution of forest soils (2023)

Forest ecosystems are extremely diverse and heterogeneous in terms of organisms, soils, waste such as wood waste, and disturbance regimes. However, little attention has been paid to the causes, intensity, self-organization and functioning of forest floor heterogeneity within individual stands. The concept of “pedogenic patches” is introduced to integrate ecology and soil formation into a holistic view of forest soil heterogeneity. We define “pedogenic patches” as spatially limited and temporally defined locations that contain at least one soil-forming factor that differs enough from its surroundings to give rise to differing intensities of soil processes and hence divergent pedogenic processes. According to this definition, individual components of soil-forming factors such as wood debris, trees, tree canopy gaps, boulders, and riverbanks can generate pedogenic patches if the rate of the pedogenic process results in a different soil morphology compared to the surrounding environment. The quantitative intensity of a pedogenic area depends on the size, age, number and characteristics of soil-forming factors and processes. Furthermore, pedogenic surfaces are the quanta of soil formation: punctiform pedogenic surfaces with some degree of intense, persistent, and resilient pedogenesis can move in forest ecosystems, thus creating patchwork soil landscapes of varying heterogeneity. Forest ecosystem studies could identify pedogenetic areas to measure soil formation and assess forest soil heterogeneity using different diversity indices. This would provide new insights into forest soil function, soil-regulated biodiversity, how forests evolve through disturbance, and the ecological trade-offs of self-organizing ecosystems.

The location of the landscape also determines soil formation and therefore the properties of the soil are related to the location of the landscape. In many landscapes, the importance of landscape position is high and there are therefore strong relationships between soil properties and landscape position. This applies in particular to agricultural landscapes in which local soil differences have been compensated for by tillage. This is less true for some forest landscapes, where the local effects of trees on soil formation have resulted in increased local variation. This raises the question of whether soil-landscape relationships are strong in natural grasslands without trees or plowing. We answer this question for natural prairie slopes in the Great Plains of the United States by quantifying soil-landscape relationships and soil spatial autocorrelation based on a data set of 100 soil observations. We find that soil-landscape relationships are weak, even taking into account the specific topographical features of the study area, and that short-term variations in soil properties are almost as large as long-term variations. We conclude that natural processes unrelated to trees disrupt the formation of clear catenas and hypothesize that this may involve small burrowing mammals and the filling of fractures in the parent material with finer material.

The integration of geomorphological and pedological investigations forms the field of soil geomorphology. The geomorphological studies of soils consist of six main elements, including the evolution of chronosequences, soils as indicators of landscape stability, soils as indicators of climate change, soil evolution and catchment area development, soils as indicators of erosion processes and deposits, and soils as indicators of Quaternary parent materials and Stratigraphy. Land surface morphology fundamentally controls the patterns of water movement through landscapes. These patterns, in turn, affect the way solid and dissolved materials move, leading to the formation of soils with special properties. This article examines the role of each of these principles in soil landscape evolution and concludes with a list of challenges faced by soil geomorphology in terms of modeling soil landscape evolution.

Because topography is a key factor in soil formation and strongly affects soil physical and chemical properties, terrain attributes are routinely used in digital soil mapping to spatially predict soil properties. Forests on flysch sediments along the northern slopes of the Swiss Alps often show strong microrelief. The dominant soil types are trough gleysols and ridge cambisols with large pH variations within short distances. Based on soil evolution theory, we expected that soil formation processes driven by microscale topographical variations would shape microscale spatial patterns of soil properties at different sites within the flysch region. Therefore, the main aim of the study was to investigate model extrapolation within flysch regions, which has proven difficult in many other geological substrates. At three sites, each with an area of ​​about 2 ha, we first created three local models to investigate whether a correlation between microtopography and topsoil pH can be derived from high-resolution terrain attributes and pH measurements. Using data from all three sites, we then calibrated a common model and examined model extrapolation by calibrating models with data from two sites and predicting the pH at the third site. All models were based on multiple linear regressions using 0.5 m resolution terrain attributes derived from a multiscale approach as explanatory variables. The R with cross validation²For local pH models, it varied between 0.56 and 0.77 and the corresponding RMSE between 0.57 and 0.64 pH units. The R²and RMSE for the joint model were 0.60 and 0.76, respectively. Results of local modeling suggest that microtopography is a dominant soil formation factor in flysch sediments, triggering soil genesis on a submeter to meter spatial scale. Although the extrapolated models showed reduced predictive power with R²With values ​​of 0.25, 0.46 and 0.53, the selected terrain attributes were relatively similar across models, which can indicate common driving processes. The results of the joint model suggest that using high-resolution terrain attributes provides a fairly accurate spatial prediction of the highly variable pH of topsoil in forests on top of flysch sediments across Switzerland.

The evolution of land plants, the first vascular plants, the first trees, and then entire forest ecosystems had far-reaching implications for Earth system dynamics. These innovations are considered important moments in the evolution of the atmosphere, biosphere, and oceans, even though the impacts may have been delayed by hundreds of thousands or millions of years. These fundamental changes in the Earth's history took place in the Paleozoic: from the Ordovician, the time of the first land plants, to the Carboniferous, which was dominated by forest ecosystems. The Devonian Plant Hypothesis (DPH) was the first concept to offer a comprehensive and logical explanation of the many environmental changes that accompanied tree/forest evolution over this period. The DPH highlighted the influence of deep-rooted vascular plants, especially trees, on the processes of weathering, pedogenesis, nutrient transport and CO₂Cycle, deposition of organic and inorganic carbon and points to other possible consequences in the marine environment (oceanic anoxia and late Devonian extinctions). Here we try to combine DPH and the related biodiversity extension, the Devonian plant explosion (DePE), with the concept of biogeomorphic ecosystem engineering (BEE). This idea connects the growth and activity of trees with the initiation and/or modification of geomorphological processes and thus with the emergence or deterioration of geomorphological forms. We focus on trees and forest ecosystems as the likely dominant driver of plant-related change. We note that while there is ample evidence that trees are important biogeomorphic ecosystem engineers, treating DPH is difficult due to limited, difficult to interpret, or controversial data. However, we argue that the BEE concept sheds new light on DPH and suggests new data sources that should be able to answer our main question: Were Devonian trees engineers of the biogeomorphic ecosystem?

Dead trees, especially fallen logs, play an important role in forest ecosystem dynamics. The contribution of decaying wood to the C and nutrient stores in the forest soil depends on the tree species and the degree of wood decay. However, the extent to which fallen logs affect soil properties in temperate forests has been poorly studied. In this study, a mixed beech forest in the Liresar region of Mazandaran Province in northern Iran was selected to investigate whether and how the presence of fallen logs affects soil quality and soil function. The soils under the degraded trunks were compared to the soils in the vicinity of two dominant tree species. (beech and hornbeam). We then examined how these effects occurred in the decay of the fallen logs by comparing the timbers of both tree species at four degrees of decay. The degree of decomposition of the fallen logs was divided into four classes (DC1-DC4). Eight dead trees of each tree species were selected in the center of each sample area. Three composite soil samples were collected under each rotting log and 100 cm from a rotting log at two soil depths (0-15 and 15-30 cm) to analyze the main soil physicochemical properties and microbial activity. The results showed that the fallen logs affected the physical soil (5% wetter than the control soils), chemical soil (2% lower pH, 100% increase in organic C and total N in the case of hornbeam and a 2% increase in in the soil) impaired P) and biologically. Properties (microbial respiration of the soil improved by 10% and microbial biomass C 620 and 351.5 mg kg⁻¹and microbial biomass N 66.47 and 32.18 mg kg⁻¹, or in the case of beech and hornbeam), resulting in soil microsites that differ markedly from those without fallen trunks. The presence of fallen logs increased soil microbial activity and soil fertility as the wood decayed. Therefore, the presence of fallen logs is an important factor affecting forest soils and must be taken into account in forest management.

Atmospheric Environment, Band 125, Teil A, 2016, S. 78-91

The aim of this work is to evaluate the impact of the use of biodiesel blends in road traffic on air quality. In this framework, the WRF-EURAD numerical modeling system was applied to air quality in Portugal and the urban area of ​​Porto, enforced by two emission scenarios (including CO, NOx, PM10, PM2.5, VOCDM, formaldehyde, acetaldehyde, acrolein and benzene). ): a reference scenario with no biofuels and a scenario where a B20 fuel (20% biodiesel/80% diesel, v/v) is used by the diesel vehicle fleet. With regard to carbonyl compounds, the emission scenarios indicate that B20 fuel can lead to a 20% increase in formaldehyde, acetaldehyde and acrolein emissions, leading to an increase in ozone equivalent production. On the other hand, air quality modeling confirmed that the use of B20 helps control air pollution and improves CO and NO₂Concentrations in urban air catchment areas are around 20% and 10%, respectively, taking into account a regional simulation grid. However, according to the city-level simulation, NO₂In the metropolitan area of ​​Porto, values ​​may increase by around 1% due to the use of B20. For the other pollutants studied, namely PM10 and PM2.5, the average concentrations across the area are reduced, but by an insignificant amount of <1%.

Rangeland Ecology & Management, Band 67, Nummer 3, 2014, S. 307-317

Fire is a major disturbance process that has historically occurred on the northern Great Plains. Previous research from the northern dry mixed-grass prairie suggests that C4 (warm season) grasses are replacing peak C3 (cool season) species with increased fire, particularly in spring. This hypothesis was tested at the landscape scale at Canadian Forces Base Suffield, Alberta by examining the relationship between ecosystem states (C3 dominant, C3/C4 codominant, C4 dominant) derived from a functional type classification of the multitemporal MODIS plant ( Pseudo R²: 0.598, overall accuracy: 0.74) and digitized annual fire history from the Landsat archive (1972-2007). Probit regression showed that succession processes were different between distribution sites, with C4-dominant pixels being positively associated with fire (P < 0.001, pseudo-R²= 1) and completely replaced the dominant C3 pixels in clay distribution areas after 14 fires in 36 years. In contrast, codominant C3 and C3/C4 pixels were associated with fires at blowout distribution sites (P < 0.001, pseudo-R²= 1), with codominant C3/C4 pixels replacing dominant C3 pixels with increasing fire. Finally, there were no statistically significant relationships between ecosystem states and fires for Sands dispersal sites. Recovery analysis revealed that after clay containing pixels suffered three to six burns in 18 years, followed by 18 years of dormancy, the dominant C3 pixels were reduced by more than 30% compared to unburned pixels. Finally, the timing of the subannual fires (2001–2009) was examined using Wilcoxon signed rank tests between the spatial extent of spring and summer fires using MODIS burned area data. The results indicate that fires are not limited to the spring season (P < 0.05) but occur throughout the growing season. Although fire timing does not appear to play a role in succession evolution, this ecosystem is generally sensitive to repeated fires, and C3-climax species take decades to recover.

Journal of Great Lakes Research, Band 39, Nummer 3, 2013, S. 437-448

The industrial pesticide dichlorodiphenyltrichloroethane (DDT) was initially touted for its effectiveness against malaria and agricultural pests, but was eventually banned in North America in the 1970s due to growing concerns about its harmful effects on wildlife. Despite the successful termination of its commercial use, the persistent and bioaccumulating nature of DDT has resulted in sustained concentrations in aquatic food chains, particularly in fish species of higher trophic levels. In this study, we used dynamic linear models to compare the temporal trends of four DDT compounds (p,p′-DDT, o,p′-DDT, p,p′-DDE, and p,p′-DDD) in nine examine fish. Species in Lake Erie from 1976 to 2007, considering both fish length and lipid content as covariates. Our results indicate that levels of p,p′-DDT and o,p′-DDT decreased, often to the limit of detection, with rates of decrease being slower in the second half of the study period. The p,p′-DDE levels were much more variable, showing large fluctuations over time (though generally with a net downward trend), with annual rates of change in the corresponding concentrations being negative or (more recently) close to zero. Similarly, p,p′-DDD levels fluctuated over time (albeit to a lesser extent), with a gradual slower decline in many fish species, such as smallmouth bass and sea bass. The results are consistent with our understanding that DDE and DDD are degradation products of p,p′-DDT and therefore continue to be produced when DDT is degraded. The declining trends seen in nearly all conspecifics and fish species indicate a reduced risk of DDT to Lake Erie fish communities.

International Quaternary, Band 516, 2019, S. 98-110

Key events in the history of the ancient city of Tanais were recorded against the backdrop of climate change from the 3rd century BC. considered. C. and ended in the V century AD. C. To reconstruct the climatic changes during the city's existence, we used palynological, microbiomorphic, and palaeopedological analyzes of palaeosoils and culture strata from the Tanais and neighboring settlements. Located on the right bank of the Tanais (Don) river near its confluence with the Sea of ​​Azov, the ancient city maintained trade and economic relations with the barbarian (nomadic) population living in the steppes near the Don and Sea of ​​Azov First Iron Age. It has been shown that the foundation of Tanais in the 3rd century BC occurred. C. and its growth up to the 2nd century BC. C. took place under climatic conditions that were comparable to those of modern times. The city's most devastating conquest by the Bosphorus king Polemon came in the late 1st century BC. C., when the aridity of the climate was at its peak and the city of Tanais probably suffered an economic crisis. Examination of the chronosequence of the soils buried under the stone walls of the city and other nearby settlements at different times revealed a decrease in organic carbon and an increase in carbonate and gypsum content in the paleosoils since the 3rd century BC. to the beginning of the 2nd century AD. These data confirm a strong climatic drought in the change of eras. As can be seen from pollen analysis, throughout the period of existence the city was surrounded by steppe communities, but coniferous (pine) pollen was also found in the spectra of all chronointervals. The highest proportion of pollen from cultivated plants and weeds (4-6%) is found in accumulations that can be assigned to the first period of city life (2nd^{North Dakota}-1. century B.C. BC). The microbiomorphic analysis was consistent with the pollen data and provided additional data on woody plants and rushes, which were extensively used for the population's economic activities in the first period of the city's existence. From the mid-2nd century to the end of the 4th century AD climatic conditions can be considered humid and favorable for bioproductivity. Another wave of droughts occurred on the border of the fourth and fifth centuries AD. At the end of the 5th century AD the city ceased to exist.

Geomorphologie, Band 197, 2013, S. 76-8

This study extends previous contributions on dynamic stream channel adjustments to base-level changes. We have studied an in situ response of self-formed cohesive channels to a basal level drop, conditions resembling a gradual change in elevation and/or climate. Empirical hydraulic geometry equations for natural cohesive clay streams are presented using data from eight canals draining perennial brackish water sources and emptying into the Dead Sea. Examination of downstream variations in flow head and power ratios suggests the existence of three distinct regions where channel adaptation to bottom level drop is unequally distributed among hydraulic geometry variables. The values ​​of the flow velocity exponent m are low (0.11 ≤ m ≤ 0.24) and the middle section of the channel has the lowest exponent. The depth exponent f has the lowest value (f≈0.3) for the highest areas of the channel, the rest have higher values ​​(f≈0.4). The smallest width exponent (b=0.35) characterizes the upper reaches. These values ​​and their spatial distribution show a regular pattern. We show that the range of the lowest channel is adjusted by profile steepness and channel taper (f>b); the mechanism that prevails in the central sections of the canal is lateral adjustment (width), the sections are transiently transformed towards equilibrium; The higher areas exhibit wide and shallow channel cross-sections resulting from a series of bank collapses and the resulting accumulation of sediments, leading to a local reduction in head and forcing further channel widening. The results of this study not only provide insight into how cohesive channels regulate their geometry, but also show how hydraulic forces overcome the resistance of the substrate, adjusting the slope and dimensions of the channel and thus affecting the range of channel morphology and models in the Scale. the power of the current.

International Journal of Multiphase Flow, Band 93, 2017, S. 1-16

Measurements of time-dependent bed shapes generated by the deposition of solid plastic particles in two-phase liquid-solid flows were performed using a novel ultrasonic echo method and video image analysis in a 100 liter closed-loop mud flow circuit. The results are presented for sediment bed thicknesses over a range of nominal flow rates and initial bed depths and combined in different phase diagrams based on different parameter combinations, categorizing bed shapes into five types. In doing so, the novel observation was made that the type of bed shape formed depends on both the flow rate and the initial relative bed or liquid depth, with waves and dunes being observed in the same system and in a single experiment. In addition, the number of critical shields at the onset of particle motion is measured as θ_{South Carolina}= 0.094 ± 0.043, hysteretic behavior is observed and the evolution and extent of each type of time-dependent bed shape are analyzed in detail and compared with various expressions for initial and equilibrium dimensions from the literature. A set of universal scales for bedforms in all types of conduit is proposed, ultimately to unify observations of bedforms in pipes with those of channels and natural flows.