Landscape Parameters Research Articles

Overview of the USDA Mid-Atlantic Regional Wetland Conservation Effects Assessment Project

This paper provides an overview of studies conducted under the USDA Mid-Atlantic Regional Wetland Conservation Effects Assessment Project (MIAR study). Under the MIAR effort, numerous studies were conducted to (1) quantify ecosystem functions provided by restored wetlands by comparing functions within depressional nontidal wetlands with a varying degree of alteration (i.e., natural wetlands, restored wetlands, and prior converted croplands [PCCs]) and (2) develop tools for wetland monitoring and assessment. We present these studies after classifying them according to wetland functional (biodiversity, biogeochemical, and hydrologic) and tool development categories (remote sensing, hydrologic modeling, and geospatial analysis). Furthermore, we provide lessons from the MIAR study’s findings for enhanced wetland conservation practices. Our overview demonstrates that restoration of wetlands contributes to enhancing wetland biodiversity, biogeochemical, and hydrologic functions in the Mid-Atlantic Region. Wetland monitoring tools that were developed as part of this study aid our understanding of wetland functions and the effect of restoration on those functions. Findings from these studies suggest that it is important to (1) establish long-term restoration plans; (2) minimize soil compaction during restoration; (3) increase wetland water storage capacity; (4) locate restored wetlands around natural wetlands to magnify restoration effects and improve water quality management; (5) consider the importance of shallow water and topography for supporting native plant species; (6) use landscape parameters for targeting and implementing restoration efforts; and (7) use wetland monitoring tools for precision management. This MIAR study provides scientific data to support wetland restoration activities and guidelines to foster the restoration of wetland-mediated ecosystem services.

Local environmental factors influence beta-diversity patterns of tropical fish assemblages more than spatial factors.

A major goal in ecology is to understand mechanisms that influence patterns of biodiversity and community assembly at various spatial and temporal scales. Understanding how community composition is created and maintained also is critical for natural resource management and biological conservation. In this study, we investigated environmental and spatial factors influencing beta diversity of local fish assemblages along the longitudinal gradient of a nearly pristine Neotropical river in the Colombian Llanos. Standardized surveys were conducted during the low-water season at 34 sites within the Bita River Basin. Physical, chemical, and landscape parameters were recorded at each site, and asymmetric eigenvector maps were used as spatial variables. To examine the relative influence of dispersal and environmental variables on beta diversity and its components, distance-based redundancy analysis (db-RDA) and variation partitioning analysis were conducted. We proposed that spatial scale of analysis and position within the river network would constrain patterns of beta diversity in different ways. However, results indicated that in this system, high beta diversity was consistent among species assemblages no matter the scale of analysis or position within the river network. Species replacement (turnover) dominated beta diversity, an indication of the importance of species sorting. These findings suggested that conservation of fish diversity in tropical rivers requires maintenance of both habitat heterogeneity (spatial variation in habitat conditions) and connectivity at the scale of entire river basins.

Major and trace elements in suspended matter of western Siberian rivers: First assessment across permafrost zones and landscape parameters of watersheds

In contrast to good understanding of chemical composition of the river suspended matter (RSM) of large rivers, small rivers remain strongly understudied, despite the fact that they can provide valuable information on mechanisms of RSM generation and transport depending on key environmental parameters of the watershed. This is especially true for permafrost-affected boreal and subarctic territories, subjected to strong modification due to permafrost thaw and landscape changes under climate warming. We selected Earth’s largest frozen peatland zone, the western Siberia Lowland (WSL) in order to test an impact of climate warming, permafrost thaw and landscape zone changes on riverine transport of particulate material from mainland to the Arctic Ocean. We sampled 33 small and medium size WSL rivers during spring flood, summer baseflow and autumn flood over a 1700 km gradient of climate and permafrost. Major and trace elements in particulate (>0.45 µm) and dissolved (<0.45 µm) fraction were analyzed. We hypothesize that future increase in active layer thickness and the change of dominant landscape from bogs and lakes to forest can be predicted via analyzing the actual pattern of RSM chemical composition across various permafrost zones and landscape parameters of WSL river watershed. We observed a minimum concentration of Li, Mg, Na, K, Rb, V, Cr, Zn, Cu, Co, Ni, Al, Ga, Y, REEs, Nb, W, Ti, Zr, Hf, Th and U in RSM collected from isolated and sporadic permafrost zones. Considering all seasons together, the presence of forest in the permafrost-bearing zone increased particulate concentrations of all alkalis and alkaline-earth elements, B, As, Nb, Mn, Co, Al, Ga, REEs, Ti, Zr, Hf, Th. This is consistent with element mobilization from mineral horizons that become available for interacting with soil fluids under forested regions. Lakes retained particulate alkaline-earths, Fe, Mn, Co, trivalent and tetravalent hydrolysates (TE3+, TE4+). The concentration of lithogenic low-soluble elements (TE3+, TE4+) in the RSM strongly increased with the river size (watershed area).Compared to the world RSM average, the WSL rivers exhibited lower concentrations of all elements except Mn and P and a low share of suspended elements relative to total (suspended + dissolved) forms of trace metals and of low-mobility (lithogenic) elements. Likely reasons for these features are: (i) low runoff and low RSM concentration as there is no rock and mineral substrate exposed to physical weathering in WSL peatland; (ii) organic, rather than mineral, nature of surrounding “solid” substrates and as a result, organic rather than silicate nature of RSM, and (iii) high DOC and Fe concentration leading to high concentrations of typically low-solubilty elements in the dissolved (<0.45 µm) fraction due to colloids.From a climate warming perspective, the increase in active layer thickness and involvement of mineral horizons into soil fluid migration in discontinuous to continuous permafrost zone will likely increase the share of particulate fraction in total element transport for many soluble (labile) elements and also lithogenic elements in WSL rivers. At the same time, permafrost boundary shift northward may decrease particulate concentrations of most major and TE in rivers of discontinuous permafrost zone. The lake drainage and forest colonization of tundra and bogs in the permafrost-affected part of WSL may increase the concentration of alkali and alkaline-earth elements, divalent metals and trivalent and tetravalent hydrolysates. As a result, export of particulate metal micronutrients and toxicants from the WSL territory to the Arctic Ocean may increase.

Creating a synthetic landscape: Spatial allocation of non-spatial single farm data

Spatially explicit farm data are often not available for farm level studies and models, limiting the accuracy of simulating environmental impacts and posing limitations to agent-based models that simulate spatial decisions under explicit consideration of neighborhood effects (e.g. as on a land market). For large regions, such as the whole EU, different approaches have been developed to address this problem, e.g. by downscaling economic model results to lower-level administrative regions or by spatially allocating farm types to homogenous spatial entities. For smaller regions and if interactions between farms have to be considered, these approaches are too coarse.Some studies make use of a synthetic landscape approach for this scale and type of analysis. Farms are placed on a grid of the area under study by ensuring that the localization of the farms fulfills the area claims of the farms. Available approaches use relatively simple techniques by considering only the grassland share in the total area of farms or farm types and use a relatively coarse resolution (1ha*1ha). In this article, we present a method for improving the synthetic landscape approach, by considering landscape parameters in the allocation of farms, using a finer resolution (25m*25m) and introducing allocation quality indicators that allow for an assessment of the overall allocation result. For the German case study region Ostprignitz-Ruppin (NUT3 administrative level), the approach delivered a relatively high overall allocation quality. We conclude that the farm maps generated by our method can be used by mathematical optimization models or agent-based models to improve their capability of simulating spatial decisions and effects. The transferability of the method to other regions is possible, subject to data availability and the type of analysis targeted.

ASSESSMENT OF THE ECOLOGICAL CONDITIONS OFFERED BY DECIDOUS STANDS FROM THE NORTHERN ROMANIA FOR THE AVIAN POPULATIONS

Bird populations are fundamental elements of forest biodiversity and play a very important role in maintaining the ecological balance and normal functions of forest ecosystems, so that they are an indicator of sustainable management taken into account at European level. Consequently, the existence or setting up by management measures of the most favourable conditions for diverse assemblages of birds is one of the objectives of sustainable forest management. For this purpose the paper aims to assess the ecological conditions offered by broadleaved stands from the northern Romania for the avian populations. The parameters considered were the stands layers, the composition and spatial distribution of forest shrubs, the stand density, the biological potential of forest species, stand age and stand ecological dynamic, landscape parameters. Using these parameters as partial favourability indices, a simple method for assessing the ecological conditions offered to bird populations based on a Total Favourability Index (TFI) is proposed for practical forest management purposes. According to this index, in the case study of the northern broadleaved managed stands, the ecological favourability for birds is medium.

Parametric Design of Quasi-Natural Waterscape Gardens Based on Big Data Technology

In order to better design the water scenes of garden, the natural water scenes of garden parameters are designed by combining the big data technology, the water scenes of garden generation rules are collected by the pseudo-natural principle, and the garden landscape parameters are designed by combining the regular production characteristics with the big data technology. In order to ensure the rationality of the principle landscape design, the pseudo-natural water scenes of garden parameters are standardized, and the standard parameters are input into the Grasshopper auxiliary simulation software, so that the optimal design scheme of the pseudo-natural dynamic correlation water scenes of garden view is automatically generated. Finally, through experiments, it is proved that the landscape simulation effect of pseudo-natural water scenes of garden parametric design based on big data technology is more satisfactory than that of traditional design simulation results.

Differential cooling effects of landscape parameters in humid-subtropical urban parks

Thermally comfortable urban parks can attract more visitors and promote the delivery of health benefits to citizens. High tree cover (TREE) and low sky view factor (SVF) are known to reduce air temperature and improve thermal comfort. However, the temperature effects of other landscape parameters are less clear, such as building volume ratio (BV), distance from sea (SEA), park area (AREA), pavement cover (PAVEMENT), road cover (ROAD), shrub cover (SHRUB), turf cover (TURF) and water body (WATER). This study aimed to identify landscape parameters that were significantly associated with air temperature in urban parks and estimate their cooling potentials through empirical models. One hundred precision sensors were installed in 14 urban parks in Hong Kong in summer 2018 to collect air temperature data. ROAD, SEA, TREE and SHRUB had the strongest impacts on temperatures. Considering a circular area with a 20-m radius, a 50% decrease in ROAD, 50% increase in TREE and SHRUB could reduce daytime mean air temperature by 0.3, 0.4 and 0.2 °C respectively. The same landscape changes would reduce nighttime mean air temperature by viz. 0.3, 0.2 and 0.2 °C. Compared to an inner-city park (500 m from sea), the empirical model suggested that daytime and nighttime mean air temperature in a waterfront park (10 m from sea) is expected to be 0.4 and 0.2 °C lower respectively. Urban parks should be sufficiently large to buffer the warming effect of roads. Very high tree cover (>90%) is recommended for an effective interception of solar radiation.

Colloidal transport of carbon and metals by western Siberian rivers during different seasons across a permafrost gradient

In contrast to fairly good knowledge of dissolved (<0.45 µm) and particulate (>0.45 µm) fluxes of carbon, nutrients and metals from the land to the ocean, colloidal (1 kDa−0.45 µm) forms of solutes are rarely quantified. This is especially true for Siberian rivers draining into the Arctic Ocean: because of organic-rich soils, colloidal fractions of elements are high and may sizably impact coastal biological processes. However, the main environmental parameters such as seasons, river size, climate, permafrost distribution and landscape parameters of the watershed controlling colloidal distribution of organic carbon (OC) and metals remain totally unknown. Here we used on-site centrifugation combined with ultrafiltration via 3, 30 and 100 kDa pore size membranes and 1 kDa dialysis to characterize colloidal size fractionation of OC and metals in 32 western Siberian rivers, ranging in size from 10 to 150,000 km2 watershed area, across a climate and permafrost gradient (from absent to continuous permafrost). The dominant forms of OC and metals was low molecular weight LMW< 3 kDa fraction and medium molecular weight (MMW3 kDa-30 kDa) colloids. The LMW< 3 kDa fraction of OC increased in the order spring < autumn < summer, following progressive replacement of allochthonous medium and high molecular weight colloids in spring by autochthonous LMW organic ligands in summer; the latter possibly occurred due to exometabolites of plankton and periphyton. The LMW OC fraction became low again in autumn, presumably due to appearance of allochthonous DOM washed out by autumn rains from peat soil at maximum thawing depth. The size of the watershed had subordinate influence on colloidal distribution compared to seasons. The effect of landscape parameters of the watershed on the colloidal status of solutes was subordinate to seasonal and permafrost-zone controls. Overall, the ongoing environmental changes in WSL will likely decrease the proportion of mineral (Fe, Al – bearing) colloids of C and trace metals exported by rivers to the Kara Sea. As a result, the flux of dissolved C, micro-nutrients and metal toxicants may become increasingly bioavailable to coastal aquatic biota.

Landscape structure and parasitoid diversity as measures of sustainable landscape

Complexity and structure of a landscape influence the presence of insect parasitoids in agricultural landscapes. Landscape structures are often formed from semi-natural habitat fragmentation, which can reduce the richness and abundance of insect parasitoid and affect their ability to suppress pest population. This study was aimed to study the effect of landscape structure on the diversity and abundance of insect parasitoids in long beans fields. In six agricultural regions, landscape parameters were calculated, i.e class area (CA), a number of patches (NumP), and mean patch size (MPS). Insect samplings were conducted using transect methods and direct collection. Results of landscape complexity did not affect the species richness of parasitoid, but it did affect the species composition. The results showed that the higher the CA of the tree, the higher the percentage of parasitization, but the higher the CA of agriculture, the lower the percentage of parasitization. This shows that there are landscape parameter indicators that can be used as a key to see the presence of parasitoids so that they can provide an indication of sustainability. Therefore, landscape structure must consider the importance of landscape management habitats for the conservation of natural enemies especially insect parasitoid as a biological control agent to create sustainable landscapes.

Effects of urban and landscape elements on air temperature in a high-density subtropical city

In this study, we examined the effects of key urban (road cover, building volume ratio, and proximity to sea) and landscape (water body, tree cover, shrub cover, turf cover, park area, and sky view factor) parameters on air temperature, and the impacts of weather conditions on landscape-temperature relationship. One hundred temperature sensors were installed in fourteen urban parks in Hong Kong during summer season to collect continuous air temperature data. Linear mixed-effect models showed that the effects of weather (cloud amount, solar radiation and wind speed) on landscape-temperature relationships were minor (<0.2 °C). Therefore, the landscape effects were further investigated using the entire dataset regardless of weather conditions. In a circular buffer zone with a 20-m radius, a 10% increase in road density caused a 0.059 °C rise in daytime mean air temperature while the same increase in tree cover and shrub cover led to a 0.052 and 0.041 °C drop in temperature, respectively. A 0.849 °C rise could be expected when sky view factor increased from 0 to 1. The proximity to the sea also had a significant daytime cooling effect (0.784 °C/1000 m). The night-time landscape effects were similar to the daytime except that the strengths of the effects on air temperature were weaker. The obtained results can be used by landscape designers and urban planners for modifying the landscape to bring cooling effects and tackle heat-island and climate-change impacts.

Recombination and mutational robustness in neutral fitness landscapes.

Mutational robustness quantifies the effect of random mutations on fitness. When mutational robustness is high, most mutations do not change fitness or have only a minor effect on it. From the point of view of fitness landscapes, robust genotypes form neutral networks of almost equal fitness. Using deterministic population models it has been shown that selection favors genotypes inside such networks, which results in increased mutational robustness. Here we demonstrate that this effect is massively enhanced by recombination. Our results are based on a detailed analysis of mesa-shaped fitness landscapes, where we derive precise expressions for the dependence of the robustness on the landscape parameters for recombining and non-recombining populations. In addition, we carry out numerical simulations on different types of random holey landscapes as well as on an empirical fitness landscape. We show that the mutational robustness of a genotype generally correlates with its recombination weight, a new measure that quantifies the likelihood for the genotype to arise from recombination. We argue that the favorable effect of recombination on mutational robustness is a highly universal feature that may have played an important role in the emergence and maintenance of mechanisms of genetic exchange.

Delayed and immediate effects of habitat loss on the genetic diversity of the grassland plant Trifolium montanum

Loss of the area and connectivity of natural and semi-natural habitats impose serious negative effects on all aspects of biodiversity. However, quantifying the effect of these pressures is difficult due to the time-lagged responses of biodiversity to landscape change. The aim of this study is to determine if genetic diversity of plant populations exhibits a delayed response to recent landscape change. Using microsatellite markers, we evaluated genetic diversity in 28 populations of a grassland plant Trifolium montanum in Estonian calcareous grasslands. We examined the response of genetic diversity to various current and historic landscape parameters assessed at two time points: (1) 2017, and (2) 1930, when the extent of grasslands in Estonia was at its maximum. Observed heterozygosity (HO) and inbreeding coefficients (FIS) were affected by historic grassland availability in the surroundings of the study populations (buffer radius of 2000 m). However, expected heterozygosity (HE) responded positively to current grassland area and to the availability of grasslands in the surrounding landscape. Allelic richness (AR) was positively related to current population size. We found evidence for recent genetic bottlenecks in half of the study populations, indicating that landscape change had a negative impact on population demography and consequent genetic diversity. Our findings suggest that regardless of major habitat loss, some measures of genetic diversity of perennial plant species may not be at equilibrium with landscape change. This calls for caution when interpreting observed patterns of plant genetic diversity and requires consideration of historic landscape context when recommending nature conservation strategies.

Linking the human appropriation of net primary productivity-based indicators, input cost and high nature value to the dimensions of land-use intensity across French agricultural landscapes

The intensification of European land use accelerated substantially in a few decades, particularly in agro-ecosystems that are facing an increasing demand for agricultural products and whose area is also constrained by other uses (e.g. urbanization). Increases in land use intensity (LUI) are characterized by increases of the agricultural outputs per land unit through management practices and/or by increasing amounts of inputs. LUI is a complex and multi-dimensional issue in which each dimension needs to be considered to have a better understanding of the impact of LUI on ecosystem functioning and biodiversity. Here, we focused on five existing LUI indicators: the Input Cost per hectare (IC/ha), assessing the expenses in inputs (fertilizers, pesticides, etc.), the High Nature Value (HNV), a scoring system of agricultural areas accounting for the presence of landscape elements and practices favorable to biodiversity, and three indices of the Human Appropriation of Net Primary Productivity (HANPP) framework, i.e. the harvested biomass (HANPPharv), the living biomass flow remaining available after harvests (NPPeco) and HANPP which combines harvested biomass and effects of land use conversion. First, we discussed how these indicators can relate to the dimensions of LUI. Then, we tested whether HANPP, HANPPharv and NPPeco were redundant with IC/ha and HNV throughout 25,758 French metropolitan municipalities, using Pearson’s correlation coefficient and Linear Mixed-effects Models, while accounting for climatic and landscape parameters. As expected, HANPP, NPPeco and HANPPharv were highly correlated with each other, but weakly to HNV and IC/ha. HNV showed a positive relationship with NPPeco but negative with HANPP and HANPPharv. The opposite findings were observed with IC/ha. These three indicators seem complementary to HNV and IC/ha indicators, linking farmland structural properties and inputs intensity. Finally, we showed how these indicators can be linked, i.e. particular combinations of the indicator values could reveal contrasting agro-ecosystems types (e.g. intensive vs extensive crop farming).

Latitudinal patterns in phylogenetic and functional diversity of Diptera in temperate bogs

AbstractConservation of biodiversity is growing in interest, and wetlands are disappearing at an alarming rate, so understanding how communities are assembled and how interactions among species and ecosystems influence evolution is critical to the management of threatened habitats. We compared diversity and assemblages of peatland Diptera within and between ecoregions in Québec, Canada. We then determined the phylogenetic structure of peatland Diptera communities and how the structure differed with spatial scale (trap, site, ecoregion). Finally, we tested alpha and beta diversity along environmental and spatial gradients to determine which processes influence Diptera communities and diversity. Bogs across the three ecoregions support similar abundance, species richness, and functional diversity. We found that the major forces structuring Diptera assemblages in bogs across Québec are stochastic processes such as dispersal limitations. However, those random patterns change to clustering when anthropogenic disturbances modify the landscape. Assembly rules are mostly dictated by patch and landscape parameters specific to each ecoregion affecting dispersal and establishment between sites. Conservation of mobile organisms in habitats such as bogs will depend on conservation plans focusing on both patch quality and surrounding landscape, and that different conservation strategies need to be applied in different ecoregions.

Digestive stimulants for calves

The results of research and production experience on calves of younger age group are presented. According to the complex of indicators studied in the experiment (feed costs, digestibility of nutrients, growth and development, biochemical status of blood, elements of behavior, microbial landscape, morbidity, morphological and histological parameters, economic efficiency of cultivation), the inclusion in the diet of dairy calves of an antibacterial stimulant of productivity (Bio-Mos) and a complex anti-stress drug (Acid-pack 4-way) had a positive impact. For all of the above indicators, the highest effect was obtained when administered to dairy feed Bio-Mos daily at a dose of 4 g/head during the entire period of cultivation.

Critical analysis of spatial-temporal morphological characteristic of urban landscape

Remote sensing and Geographical Information System (GIS) data have been used widely to analyze and study the patterns of urban expansions. Urban expansions are intricate dynamic process associated with landscape transformation and its driving factors. Previous studies mainly focused only on identifying urban change; therefore, in this study, we have developed a spatial-temporal morphological model to identify the pattern of urbanization and driving factors contributing the growth pattern. The primary objective of this study is to identify and analyze the urban sprawl of Lucknow city, India, as a pattern and process. Quantification of urban landscape is performed using remotely sensed temporal satellite images of 1990, 1999, 2009, and 2016 over a period of 26 years. An interlink between spatial metrics, gradient analysis, and density index has been developed to analyze the directional growth of the city. Gradient modeling is performed using moving window analysis on a single grid for quantification of the landscape structure. Multi Ring Buffer (MRB) approach has been deployed to measure the extent and trends of urbanization. The quantification of MRB is performed using Shannon’s entropy estimations. The analysis of spatial data is then carried out by splitting the study area into five circular zones of 2 km each in increasing order of radius. The higher value of Shannon’s entropy index shows a highly coalesced urban center with dispersed growth towards the outskirts. Urban gradient analysis is performed to model the landscape parameters and urban growth morphology in 16 different directions. Total 257 sample points from the city center at the interval of 500 m are overlaid on temporal dataset up to 8 km in 16 different directions. To compute the compactness of urban sprawl for the present scenario, density index is evaluated. The outcome from the study indicates an integrated approach for modeling the urban morphology which illustrates the extent of influencing drivers of urbanization in various directions.

Identification of energy landscape of Sp1 zinc-finger in Pb(II) or Cd(II) using AFM

The interaction between the zinc finger transcription factor (ZF–TF) and a specific DNA sequence is characterized by energy landscape parameters such as the dissociation rate constant and binding free energy. Heavy metals, such as lead (Pb) and cadmium (Cd), disturb transcription processes by changing the DNA-binding affinities of ZF–TF. To investigate the interference of heavy-metal ions with DNA transcription, we determined the unbinding force between ZF–TF and DNA by atomic force microscopy (AFM). The results suggest that the binding affinity of this complex is stronger in Pb(II) solution than under normal conditions, while the binding affinity in Cd(II) solution is weaker than under normal conditions. Thus, ZF–TF is an important target for heavy metal poisoning. Gold (Au) has a high affinity with cysteine residues, and so, it effectively coordinates with ZF–TF. AFM was employed to detect the molecular interaction force between ZF–TF and DNA in an Au(I) environment. Data analysis demonstrated that Au(I) helps restore normal binding affinity. The measurement of the unbinding force enabled us to quantify the binding free energy in the dissociation process. Alterations of kinetic parameters, which describe the energy landscape, are associated with metal poisoning disease and can be used to screen drugs for heavy-metal induced disease.

Определение оптимальных показателей продуктивности агроэкосистем в условиях Ленкоранской низменности Азербайджана

The real and prognosticated dimensions of the farming lands productivity under natural agroecosystems in the Lankaran lowland condition have been defined. It was determined that the soil, climate, subsoil level and other factors of the landscape influence on the farming land productivity under the Lankaran Lowland condition. The productivity of cereals on these soils is 45.2 centner/ha, vegetables 318.2 centners per hectare, tea 81.2 centners per hectare, fruit 62.1 centner/ha. With the implementation of agroecological measures to increase the fertility of yellow–meadow soils, it is optimal to forecast cereals for 48.2 centners/hectare, 323.2 centner /ha for vegetables, 85.4 hectares for tea, and 66.2 centners per hectare for fruit. The lowest productivity in the hydromorphicallyholophytefacies groups of soil formation, in the soils of the given facies group, the productivity of wheat is 29.0...18.3 centner/ha, vegetables 214.3...99.1 centner / ha, natural fodder for air–dry weight of 19.2...4.1 c/ha. Soils related to the facies group of hydromoric-holophytic soil formation are characterized by low scores, which is explained with unfavorable conditions of formation on the one hand and high toxicity of readily soluble salts on the other hand. In order to reduce the concentration of salts along the soil profile on the territory of the research object, it is proposed to use agro-meliorative measures, taking into account the landscape parameters and the physico-chemical agro-meliorative and physico-mechanical properties of soils. In addition, in connection with the purpose of lowering the level of groundwater in the direction of the Caspian Sea, it is necessary to conduct a main drainage and collector system, on the basis of which the main part of the salts accumulated in the soil will be removed.

Goodness of fit testing in dynamic single-molecule force spectroscopy.

Dynamic single-molecule force spectroscopy (SMFS) is a powerful method to characterize the mechanical stability of biomolecules. We address the problem that the standard manner of reporting the extracted energy landscape parameters does not reveal the intrinsic statistical errors associated with them. This problem becomes particularly relevant when SMFS is used to compare two or more different molecular systems. Here, we propose two methods that allow for a straightforward test of statistical significance. We illustrate the power of the methods by applying them to the experimental results obtained for three dimeric coiled coils of different lengths. Both methods are general and may be applied to any problem involving the fit of models with two correlated parameters.

Evaluation of SWAT Impoundment Modeling Methods in Water and Sediment Simulations.

Worldwide studies show that 80-90% of all sediments eroded from watersheds is trapped within river networks such as reservoirs, ponds and wetlands. To represent the impact of impoundments on sediment routing in watershed modeling, Soil and Water Assessment Tool (SWAT) developers recommend to model reservoirs, ponds and wetlands using impoundment tools. This study evaluates performance of SWAT impoundment tools in the modeling of a small, agricultural watershed dominated by lakes and wetlands. The study demonstrates how to incorporate impoundments into the SWAT model and discusses and evaluates involved parameters. The study then recommends an appropriate calibration sequence, i.e., landscape parameters calibration, followed by pond/wetlands calibration, then channel parameter calibrations and, lastly, reservoir parameter calibration. Results of this study demonstrate that not following SWAT recommendation regarding modeling water land-use as an impoundment depreciates SWAT performance and may lead to misplaced calibration efforts and model over-calibration. Further, the chosen method to model impoundments' outflow significantly impacts sediment loads in the watershed, while streamflow simulation is not very sensitive. This study also allowed calculation of mass accumulation rates in modeled impoundments where the annual mass accumulation rate in wetlands (2.3 T/ha/yr) was 39% higher than mass accumulation rate in reservoirs (1.4 T/ha/yr).