Grass Vegetation Research Articles

The Importance of Coprophagous Macrodetritivores for the Maintenance of Vegetation Heterogeneity in an African Savannah

Grazing ecosystems are often characterized by dynamic vegetation structure mosaics of short grazing lawns and tall grass vegetation that are important for the biodiversity and functioning of these ecosystems. Grazing-induced trampling, causing soil compaction and reduced water infiltration, has been shown to be an important mechanism for lawn grass formation. However, insights in reverse bioturbation mechanisms were mostly lacking, especially how tall vegetation persists under continuous grazing by herbivores. In this study, we explore if defecation by large herbivores in combination with different groups of coprophagous macrodetritivores can locally convert compacted grazing lawn patches back to tall bunch grasslands with a more loose soil. Across a rainfall gradient in an African savannah, we separated the potential roles in this process between dung beetles versus earthworms and termites. We placed different mesh sizes under dung piles and studied the consequences for soil, vegetation, and hydrological properties. We found that soil water infiltration rate, soil organic matter content, electrical conductivity, bunch grass cover, and bunch grass biomass were significantly promoted by dung addition, irrespective of position along the rainfall gradient. In addition, the presence of tunneling dung beetles significantly increased water infiltration rate and biomass of bunch grasses, pointing at a new mechanism whereby macrodetritivores affect the structure and diversity of plant communities. We conclude that coprophagous macrodetritivores interact with large herbivores in contributing to the maintenance of structural heterogeneity in the vegetation of grazing ecosystems, with a special role played by soil-tunneling dung beetles.

Transformation of physicochemical soil properties along a mountain slope due to land management and climate changes — A case study from the Karkonosze Mountains, SW Poland

The gradients of soil physicochemical properties along mountain slopes and across climate-elevation gradients were studied in the Karkonosze Mountains, focusing on the human-impacted zonality of the vegetation cover. The main focus of the study was the environmental consequences, both human-induced and spontaneous, of vegetation changes in the mountains which may occur due to climate change. In soils developed from granite, a clear altitude-related differentiation of soil properties was manifested by: (i) an increase in total organic carbon (TOC) with elevation; (ii) an increase in exchangeable acidity and aluminum (Alex); (iii) a decrease in pH, (iv) a decrease in base saturation; and (v) finer soil texture and higher content of base cations in the foothills and lower slopes. These altitude-dependent trends have a threshold-type distribution, i.e. the values stabilize at 750–1000ma.s.l. or are reversed in the subalpine zone. Grass vegetation decreased TOC and Alex, but increased soil pH and base saturation compared with forest vegetation at the same altitude zone. Soils under spruce had higher TOC but lower pH compared with beech stands.Present-day changes of mountain area management in Central Europe, i.e. the replacement of spruce monocultures with beech or mixed stands in the lower forest zone and reforestation (mainly with spruce or mountain pine) of abandoned meadows and pastures at and above the timberline significantly influence topsoil properties, but there is a contrasting direction of changes in the lower and upper altitude zones. Expected climate changes may shift the upper limits of the individual forest zones and reinforce the ongoing changes in forest management. The final regional result of changes is difficult to calculate and strongly dependent on the degree of anthropogenic transformation of vegetation cover. However, both the current changes in management practices and possible climate changes will reinforce the existing vertical gradients of mountain soil properties, including the elevation-related increase in TOC, exchangeable acidity and Alex, as well as the decrease in soil pH and base saturation.

Soil quality of semi-arid conservation reserve program lands in Eastern New Mexico

ABSTRACTA study was conducted to evaluate selected soil quality indicators in lands that have been in Conservation Reserve Program (CRP), which is a federal program in the United States offering annual rental payments and cost-share assistance to farmers who establish long-term vegetation covers on their erosion prone lands. The study site has semi-arid climate, and soils with grass vegetation covers for 15 years were compared with adjacent cultivated croplands that have never been in the CRP. Field measurements were performed and surface soil samples (0–0.15 m) were collected from multiple sites having either coarse textured or fine textured soils. Soil measurements assessed included bulk density (BD), penetration resistance (PR), wet aggregate stability (WAS), dry aggregate size distribution (DASD), soil organic matter (SOM), permanganate oxidizable carbon, nitrate nitrogen, extractable potassium and phosphorus, electrical conductivity, pH, sodium adsorption ratio, and soil micronutrients (copper, iron, manganese, and zinc). Results showed a significant effect of CRP management compared to the cropped fields for BD, WAS, and PR only, with the CRP fields being less compacted and having higher WAS than the cropped lands. CRP land did not significantly differ from cropped lands in SOM and for many other measurements. The effect of soil texture was significant for DASD, SOM, copper, and manganese, with the fine textured soils having more favorable measurements than the coarse textured soils. CRP management did not produce significant increase in topsoil SOM compared to cropped lands of the study area.

Paleosoils as an Indicator of Climate Change in the Late and Middle Pleistocene of the Center of the East European Plain

In sections of the loess-soil series of the Central part of the East European plain, the Mikulin interglacial paleosoils were formed according to texture-differentiated type with predominance of the processes of lessivage and possible podzolization in similar climatic conditions with modern climate. The Kamenka interglacial paleosoils contained the signs of the processes of argillization and lessivage and were formed in more humid conditions than the Mikulin interglacial paleosoils. The Inzhavino interglacial paleosoils were formed under forest vegetation, where the texture and differentiated paleosoils were formed by eluvial-illuvial type involving process of lessivage, as well as with significant involvement of the processes of surface-gleying or podzolization. It points to conditions, similar to conditions of formation of the Kamenka interglacial soils, but with more intense processes of hydromorphism. Interstadial paleosoils of the late and middle Pleistocene were formed under grass vegetation in semiarid conditions.

Reprint of: Active subspaces for sensitivity analysis and dimension reduction of an integrated hydrologic model

Integrated hydrologic models coupled to land surface models require several input parameters to characterize the land surface and to estimate energy fluxes. Uncertainty of input parameter values is inherent in any model and the sensitivity of output to these uncertain parameters becomes an important consideration. To better understand these connections in the context of hydrologic models, we use the ParFlow-Common Land Model (PF-CLM) to estimate energy fluxes given variations in 19 vegetation and land surface parameters over a 144-hour period of time. Latent, sensible and ground heat fluxes from bare soil and grass vegetation were estimated using single column and tilted-v domains. Energy flux outputs, along with the corresponding input parameters, from each of the four scenario simulations were evaluated using active subspaces. The active subspace method considers parameter sensitivity by quantifying a weight for each parameter. The method also evaluates the potential for dimension reduction by identifying the input–output relationship through the active variable – a linear combination of input parameters. The aerodynamic roughness length was the most important parameter for bare soil energy fluxes. Multiple parameters were important for energy fluxes from vegetated surfaces and depended on the type of energy flux. Relationships between land surface inputs and output fluxes varied between latent, sensible and ground heat, but were consistent between domain setup (i.e., with or without lateral flow) and vegetation type. A quadratic polynomial was used to describe the input–output relationship for these energy fluxes. The reduced-dimension model of land surface dynamics can be compared to observations or used to solve the inverse problem. Considering this work as a proof-of-concept, the active subspace method can be applied and extended to a range of domain setups, land cover types and time periods to obtain a reduced-form representation of any output of interest, provided that an active subspace exists.

Crop rotation modelling—A European model intercomparison

Diversification of crop rotations is considered an option to increase the resilience of European crop production under climate change. So far, however, many crop simulation studies have focused on predicting single crops in separate one-year simulations. Here, we compared the capability of fifteen crop growth simulation models to predict yields in crop rotations at five sites across Europe under minimal calibration. Crop rotations encompassed 301 seasons of ten crop types common to European agriculture and a diverse set of treatments (irrigation, fertilisation, CO2 concentration, soil types, tillage, residues, intermediate or catch crops).We found that the continuous simulation of multi-year crop rotations yielded results of slightly higher quality compared to the simulation of single years and single crops. Intermediate crops (oilseed radish and grass vegetation) were simulated less accurately than main crops (cereals). The majority of models performed better for the treatments of increased CO2 and nitrogen fertilisation than for irrigation and soil-related treatments. The yield simulation of the multi-model ensemble reduced the error compared to single-model simulations.The low degree of superiority of continuous simulations over single year simulation was caused by (a) insufficiently parameterised crops, which affect the performance of the following crop, and (b) the lack of growth-limiting water and/or nitrogen in the crop rotations under investigation. In order to achieve a sound representation of crop rotations, further research is required to synthesise existing knowledge of the physiology of intermediate crops and of carry-over effects from the preceding to the following crop, and to implement/improve the modelling of processes that condition these effects.

Phosphorus Removal With Grass In An Apple Orchard Under Influence Of Mulch And Irrigation

Phosphorus leaching from intensive agriculture systems is one of major contributors responsible for pollution of ground-water and surface water bodies. The aim of this study was to determine the content of phosphorus in orchard lawn for reduction of phosphorus fertilizer application and to include the phosphorus from mown grass into P balance and turnover calculation. The investigation was done at the Latvia State Institute of Fruit–Growing in 2009. Three treatments were compared: control, mulch and fertigation. Inter-row strips were covered by grass vegetation. Grass samples were collected at the time of grass mowing. The removal of phosphorus was calculated as kilograms per hectare area. The concentration of phosphorus in the lawn and the height of grass growth were significantly influenced by the mowing time and the soil moisture treatment. These results can be a base for further studies of phosphorus turnover in an orchard, as well as for fertilizer planning and management.

COMPETITION BETWEEN APPLE-TREES AND GRASS IN THE ORCHARD

The objective of the research was to study the possible competition between roots of apple-trees and grass under the influence of applied moisture regulation methods. No analogical research has been performed in Latvia so far. The investigation was done on the base of an existing trial planted in 1997 with cultivar `Melba` at 1.5 × 4 m planting distances. Three different treatments of soil moisture management were compared: control, sawdust mulch and fertigation. Inter-row strips were covered by grass vegetation (Lolium perenne and Poa pratensis, in proportion 1:3). The horizontal and vertical spacing of the main root mass was determined, as well as the distance and depth of the spread of grass roots from the inter- row strip into the tree strip. The results of the research show that mulching and fertigation have significant influence on the horizontal and vertical root spacing of grass grown in the inter-row strip, which can be an evidence of competition between apple-trees and grass for water and nutrients.

Active subspaces for sensitivity analysis and dimension reduction of an integrated hydrologic model

Integrated hydrologic models coupled to land surface models require several input parameters to characterize the land surface and to estimate energy fluxes. Uncertainty of input parameter values is inherent in any model and the sensitivity of output to these uncertain parameters becomes an important consideration. To better understand these connections in the context of hydrologic models, we use the ParFlow-Common Land Model (PF-CLM) to estimate energy fluxes given variations in 19 vegetation and land surface parameters over a 144-hour period of time. Latent, sensible and ground heat fluxes from bare soil and grass vegetation were estimated using single column and tilted-v domains. Energy flux outputs, along with the corresponding input parameters, from each of the four scenario simulations were evaluated using active subspaces. The active subspace method considers parameter sensitivity by quantifying a weight for each parameter. The method also evaluates the potential for dimension reduction by identifying the input–output relationship through the active variable – a linear combination of input parameters. The aerodynamic roughness length was the most important parameter for bare soil energy fluxes. Multiple parameters were important for energy fluxes from vegetated surfaces and depended on the type of energy flux. Relationships between land surface inputs and output fluxes varied between latent, sensible and ground heat, but were consistent between domain setup (i.e., with or without lateral flow) and vegetation type. A quadratic polynomial was used to describe the input–output relationship for these energy fluxes. The reduced-dimension model of land surface dynamics can be compared to observations or used to solve the inverse problem. Considering this work as a proof-of-concept, the active subspace method can be applied and extended to a range of domain setups, land cover types and time periods to obtain a reduced-form representation of any output of interest, provided that an active subspace exists.

Effects of reforestation on degraded soils in the moist semi deciduous zone of West Africa

Reforestation with trees and shrubs may be an effective means of increasing soil organic matter content and for regeneration of degraded lands. A study was conducted on a degraded farmland Chromic Luvisol (UNESCO/FAO) or Udic Rhodustalf (USDA, 1999) in the moist semi deciduous zone of West Africa, near Onwe, located at latitude 06 o 41’ N, longitude 01 o 28’ W, and at an altitude of 305m asl. The objective of the study was to quantify the improvement in soil physicochemical properties of degraded Chromic Luvisol with exotic leguminous tree species compared to grass vegetation in the moist semi-deciduous zone of West Africa. To quantify changes due to reforestation, we measured some physical and chemical properties of soil after 20 years (1989 – 2009) of reforestation with Acacia angustissima (Acacia), Cassia siamea (Cassia), and Leucaena leucocephala (Leucaena) mixed and compared with soils under natural grass vegetation. Experimental design used for soil sampling and for evaluating the soil properties was randomized complete block with three replications. Soil organic matter increased from 1.19% to 2.02% while pH dropped from 5.65 to 4.79 in the reforested soils. Cumulative infiltration, infiltration rate, and gravimetric water content showed significant improvement under reforestation compared with soils under natural vegetation. Total porosity increased from 36.7% in the natural grass cover to 51.3% in the reforested soils. Reforestation resulted in significant reduction in bulk density from 1.67 to 1.26g/cm 3 . Improvement of soil properties under reforestation indicates that planting of well-adapted and fast-growing exotic tree species can gradually improve soil quality and regenerate degraded lands. Reforestation may be thus recommended as a way of regenerating degraded land. Keywords : Degraded soil, reforestation, trees, soil organic matter

Growth performance of Sainfoin and its effects on the runoff, soil loss and sediment concentration in a semi-arid region of Turkey

Vegetation is one of the key factors affecting soil erosion in semi-arid environments. The evaluation of the influence of Sainfoin on soil erosion can provide important information about soil and water conservation. In this study, the effects of vegetation destruction and vegetation restoration on soil erosion were quantified using data from field runoff plots established in a semi-arid zone in Northeastern Turkey. This study was performed between 2005 (June) and 2009 (January). The experimental design at the site included a randomized complete block with four replicates (a total of 12 experimental plots: 3 treatments×4 replicates). Each plot was 20-m long×5-m wide, which is wide enough to minimize edge effects and large enough for downslope rills to develop. The control plot (A) was maintained, bare of vegetation by manual removal of the plant cover and, regular herbicide treatments. In the second plot (B), Sainfoin was seeded in 25cm wide and 60cm long rows, at a density of 8.5g of seeds per square meter in October, 2005 after clearing the existing vegetation. The third plot contained natural vegetation shrub (Paliurus spina-christi Mill.) and perennial grass (Cynodon dactylon L., Achillea sp., Astragalus sp.) vegetation (C) that maintained at an approximately 63% coverage (October, 2005) of the soil surface.From 4 randomly selected quadrats (1m×1m) at a vegetation plot, the vegetation cover of all of the plant species was estimated for each cell, and the average vegetation cover for a plot was calculated. The plant height and cover were recorded monthly from March through October in 2006, 2007 and 2008, and the monthly averaged value for each indicator was used in this study.Rainfall was recorded at the same field at 1-min intervals using a tipping-bucket system linked to a data-logger. The erosion plot results presented in this study clearly indicate a decrease in the erosion rates over time. The highest sediment concentration was measured on bare plots (10.4gl−1, 2006), while the lowest sediment concentration was measured on Sainfoin plots (1.76gl−1, 2008). The effective soil conservation ability of Sainfoin differed between seasons and years. In the spring season, when plant cover was 30%, Sainfoin began to exhibit an effective active soil conservation ability. In contrast, when the plant cover was greater than 50%, effective protection was observed in the summer. The results revealed that the plant cover was the main factor reducing surface runoff and sediment production, and that Sainfoin showed a great potential to both reduce erosion and runoff.

Influence of historical manmade alterations on soil-forming processes in a former imperial estate (Shirogane-goryouchi), the Institute for Nature Study: Development of a soil evaluation technique and importance of inventory construction for urban green areas

The influence of historical land use on soil-forming processes was assessed in a former imperial estate (Shirogane-goryouchi), the Institute for Nature Study, as one of the urban green areas where many records on land use and vegetation history have been maintained. The area of study was divided into several subsections and categorized based on land use history. Results from a soil survey in each categorized area showed that Andosols were dominant across all areas, and that past construction activities, creation of artifacts, and soil cutting and banking resulted in a disruption of horizon sequences and shifts in soil components. Soil was characterized using chemical analyses of oxalate-extractable Al (Alo) and Fe (Feo), the melanic index (MI) of soil organic matter (SOM), and the carbon stable isotope ratio (δ13C) of soil. These parameters helped researchers assess the influence of land use on soil and vegetation over time. After land use ceased, newly accumulated organic horizons, the development of soil structures, and horizon differentiation due to forest regeneration were apparent. δ13C of soil suggested that SOM in surface horizon (A, A1) was primarily derived from present-day forest vegetation (C3 plants) with MI values >1.7. The origins of SOM in subsurface horizon (A2, AB) were mixed with present-day C3 plants and past grass vegetation from C4 plants. MI values were lower in subsurface horizons due to a higher degree of humification as compared to surface horizon values. The absence of fresh organic matter supply after deforestation and lack of soil material mixing between surface and subsurface horizons after land use changed affected the state of soil organic matter in the subsurface horizon. Alo leached from surface to deeper horizons via large inputs of organic material over the long term (approximately 400 years), even on sections of earthworks. Even though the soil in this urban green area had a complex land use history, it was still possible to evaluate the soils in terms of pedogenesis with a multidisciplinary approach that explored land use and vegetation history, and used soil surveys and soil chemical characteristics to answer our questions.

Removal efficiencies of vegetation-specific filter strips on nonpoint source pollutants

A field experiment was conducted to examine the removal efficiencies of different autochthonous vegetation-specific filter strips on nonpoint source pollutants (NPSPs) and to identify their major influencing factors under various conditions. Furthermore, the effects of five major influencing factors on the removal efficiencies were analyzed. We found that the removal efficiencies in total suspended solid (SS), total nitrogen (TN) and total phosphorus (TP) of the grass vegetation filter strip were significantly higher than those of the seabuckthorn bushy vegetation filter strip. The averaged SS concentration and mass removal efficiencies of the VFS were commonly above 90%, respectively. The TN concentration removal efficiency ranged from 50 to 70%, and the mean TN mass removal efficiency ranged from 70 to 90%. The mean concentration and mass removal efficiencies in particulate nitrogen (PN) were approximately 85 and 95%, respectively. However, the concentration and mass efficiencies in dissolved nitrogen (DN) were lower. The TP concentration removal efficiency averaged 86%, and the mean TP mass removal efficiency was about 94%. The mean concentration and mass removal efficiencies in particulate phosphorus (PP) were approximately 88 and 96%, respectively. Moreover, the concentration and mass efficiencies in dissolved phosphorus (DP) were not significantly high. This suggests that PN is the main loss form of N and PP is the major loss form of P. Overall, the mass removal efficiencies of various species of VFS on nonpoint source pollutants in various forms were higher than the concentration removal efficiencies. Additionally, the removal efficiencies of VFS on nonpoint source pollutants were subject to many factors such as vegetation coverage, initial soil water content, width of VFS, inflow discharge and inflow concentration. However, the most important influencing factors are vegetation coverage, width of VFS and inflow concentration. The width of VFS plays an essential role in N and P removal efficiencies, in that even though the width of VFS is longer, the removal efficiency of VFS is not really better. Additionally, the removal of SS should be firstly considered during the course of the application of VFS due to the SS correlating well linearly with TN and TP. Nevertheless, routine maintenance is also quite necessary to keep in good removal performance of VFS.

Conservation agriculture impact for soil conservation in maize–wheat cropping system in the Indian sub-Himalayas

Conservation agriculture (CA) is considered as a suitable technique for soil erosion control, productivity enhancement, and improved economic benefits. To investigate these issues, an experiment was conducted under rainfed conditions using grass vegetation strip (VS) with minimum tillage, organic amendments and weed mulch during June 2007–October 2011 at Dehradun, Uttarakhand in the Indian Himalayan region. Results showed that the mean wheat equivalent yield was ~47% higher in the plots under with CA compared with conventional agriculture in a maize–wheat crop rotation. Mean runoff coefficients and soil loss with CA plots were ~45% less and ~54% less than conventional agriculture plots. On average, after the harvest of maize, soil moisture conservation up to 90cm soil depth for wheat crop was 108% higher under CA than conventional agriculture plots. The net return from the plots with CA was 85% higher, and when expressed net return per tonne of soil loss, it was four and half times higher than conventional practice. Results demonstrate that the suitable CA practice (a grass strip of Palmarosa with applied organic amendments (farmyard manure, vermicompost and poultry manure) along with weed mulching under conservation tillage) enhances system productivity, reduces runoff, soil loss and conserve soil moisture.

Riparian buffer zones as pesticide filters of no-till crops.

Several studies have pointed to the potential benefits of riparian vegetation as buffer zones for agricultural and industrial pollutants harmful to aquatic ecosystems. However, other studies have called into question its use as an ecological filter, questioning the widths and conditions for which they are effective as a filter. In this work, we have investigated the buffering capacity of the riparian one to retain pesticides in the water-saturated zone, on 27 sites composed by riparian buffer zones with different vegetation structure (woody, shrubs, or grass vegetation) and width (12, 36, and 60 m). Five pesticides were analyzed. The effectiveness of the filtering was largely influenced by the width and vegetation type of the buffer zone. In general, decreasing pesticide removal followed in this order wood > shrubs > grass. The 60 m woody buffer zone was the most effective in the removal of all the pesticides. Only atrazine was detected in this case (0.3 μg L(-1)). Furthermore, a linear correlation (R (2) > 0.97) was observed in their removal for all compounds and buffer zones studied. Thus, preserving the woody vegetation in the riparian zone is important for watershed management and groundwater quality in the no-tillage system in temperate climate.

True metabolizable energy of American black duck foods

ABSTRACTUnderstanding the true metabolizable energy (TME) of foods is critical to estimating the energetic carrying capacity of landscapes for migrating and wintering waterfowl. We estimated gross energy, nutrient composition, and TMEN (TME corrected for zero nitrogen balance) for 7 foods that are commonly found in the diet of American black duck (Anas rubripes) and other waterfowl wintering along the Atlantic Coast. TMEN values ( ± SE) were 3.66 ± 0.12 kcal/g for mummichog (Fundulus heteroclitus), 2.02 ± 0.12 kcal/g for grass shrimp (Palaemonetes intermedius, P. pugio, and P. vulgaris), 1.57 ± 0.11 kcal/g for fiddler crabs (Uca minax, U. pugilator, and U. pugnax), 1.42 ± 0.13 kcal/g for sea lettuce (Ulva lactuca), 1.39 ± 0.12 kcal/g for saltmarsh cordgrass seeds (Spartina alterniflora), 1.10 ± 0.14 kcal/g for widgeon grass vegetation (Ruppia maritima), and 0.77 ± 0.16 kcal/g for saltmarsh snails (Melampus bidentatus). TMEN estimated for foods in this study will assist conservation planners in carrying out bioenergetics modeling along the Atlantic Coast. © 2014 The Wildlife Society.

Saccharum spontaneum: an underutilized tall grass for revegetation and restoration programs

Saccharum spontaneum L. is a perennial tall grass and invades naturally abandoned and pastoral lands in many tropical countries. Although it is a potentially multiple-use and multifunctional species, it remains neglected and underutilized. It is commonly known as ‘Wild cane’ in English and ‘Kans’ in Hindi. In recent years, S. spontaneum has attracted serious attention for its potential in ecological restoration. The present paper deals with geographic distribution, ecology, morphological description, multiple uses, restoration potential, and propagation of this species. We also report the suitability of S. spontaneum for the restoration and stabilization of bare fly ash (FA) dumps. In this context, the highest importance value index, visual observations and practitioner insights reveal that S. spontaneum has great ability to grow on bare FA dumps and can be used as an ecological tool in restoration of vast tracts of fly ash dumps across the world. Besides grass vegetation study, we also report the change in physicochemical properties of abandoned site and compared with naturally colonized site with S. spontaneum of FA dumps to assess its ecological suitability for restoration of bare FA dump. Overall, the field results showed that S. spontaneum is a promising and potential tall grass for the restoration of FA dumps.

Effect of Artificial Sea Grass on Wave Attenuation- An Experimental Investigation

An experimental study to validate the exponential attenuation of wave height is presented. Coastal vegetation can often attenuate the wave height as well as the wave energy and are, therefore, of interest. The tests were carried out with submerged artificial sea grass vegetation meadow of 2 m length in a wave flume 50 m long, 0.74 m wide and 1.1 m deep. The model plants were prepared from 0.0001 m thick polyethylene plastic sheets with 0.01 m high stipes and 0.21 m long leaves. Regular waves were generated and the wave heights within the vegetation zone measured. For a water depth of 0.40 m, and wave periods 1.8sec and 2sec, five different wave heights ranging from 0.08 m to 0.16 m at an interval of 0.02 m were generated. Measurements of wave heights at different locations along the vegetation meadow indicate that as the wave propagates through the sea grass, there is an exponential decay in wave height.

Experimental Order 1 soil survey of vacant urban land, Detroit, Michigan, USA

An Order 1 soil survey was made of a vacant lot<0.1ha in size using a square grid with a two meter spacing (n=90 points) to test the hypothesis that there is a mappable pattern of anthropogenic polypedons against the alternative that the distribution is random. The vacant lot was formed circa 1998 by demolition of a wood-frame home from the 1920s in an urban residential setting in Detroit, Michigan. The anthropogenic soils studied were formed on a 0–2% slope under grass vegetation from artificial fill comprised of a mixture of poorly drained native soil materials, glacial sediments and artifacts (objects of anthropogenic origin), mainly waste building materials. The results suggest that anthropogenic soils on vacant urban land are mappable, even at the scale of a single vacant lot. The soils approximated an anthrosequence, i.e. a genetically related group of profiles whose characteristics differ mainly as a result of anthropogenic activity. The anthrosequence is comprised of soil phases whose range of characteristics can be used to define anthropogenic taxa, or to characterize the map unit composition of native soil–urban land complexes found on vacant property produced by building demolition. The results also suggest that, in the absence of historic records, demolition site history can be reconstructed from the spatial distribution of artifacts and soil types. More Order 1 surveys are needed to define the characteristics of anthrosequences in other urban settings and involving different soil orders, and to develop predictive urban soil–landscape models needed to provide better interpretive information for users of urban soil survey maps.

NFLUENCE OF SALTED ENVIRONMENT ON FODDER HERBS EFFICIENCY OF PASTURABLE PHYTOCOENOSES OF THE NORTH-WESTERN CASPIAN LOWLAND

The changes in the intensity of biological processes in the vegetation and productivity of forage grasses depending on the degree of soil salinity of the North-West Caspian Lowland were studied. Salination factors are specific. They are formed because of their adaptive nature, providing for species the opportunity to get the certain position in the relevant biocenosis. As a result each species produces its own strategy of life. Development of saline processes of soil in the growth and development of the plant mass, biological and agronomic salt resistance is clearly seen. Biological salt resistance is characterized by the ability to maintain the viability of the plant body at the upper limit of salinity. Agronomical salt resistance is determined by the value of crop and productivity. Adaptive possibilities of different plant species with different biological characteristics were also examined. Subject, objective of the work. Productivity of vegetation of semidesert ecosystems and dynamics under the influence of salinity forage grass pasture phytocenoses of the North-West Caspian Lowland were studied. Test method. We studied fodder crops: wheat grass long ( Elytrigia elongata ), ctenoid wheatgrass ( Agropirum cristatum ) and alfalfa ( Medicago sativa ). The crop from each significant area was weighed; it was taken from the average sample weighed in at 1 kg in a gauze bag for drying at a temperature of 60–65 °C in airing cupboard where brought to constant weight. Accounting for phytomass was carried by laying mowing area 8–10 times. Dimensions of mowing fields are 0.25 m2, that ensured coverage of all dominant plants. Results. At mid-saline meadow-chestnut soil of the North-West Caspian Lowland wheatgrass long gives the highest yield of green mass – 18,1 tons per hectare of dry weight average for 2003–2010. Alfalfa crop is in the second place, that is less than bluegrass by 18.0 % (2.9 tons per hectare). The least yield of these crops is ctenoid wheatgrass, which is less than other grasses by 4.8 tons per hectare (26.1 %) and 1.7 tons per hectare (11.3 %). Therefore, wheatgrass long is hardier to mid-saline soil than other species. High yield of alfalfa depends on frequent mowing of this grass. In the sowing year there were three hay crops, the second and subsequent years - 4 mowing. The share of the first mowing in the sowing year alfalfa has 33.0 %, the second 42.3 %, the third 24.7 %. In the second and subsequent years the share of the first mowing in the total yield of green mass increases up to 28,3–28,8, the third to 19,0–20,6, the fourth to 8,8–10,7 %. Area of application. The research results can be used by the economic organizations and enterprises for the phytomelioration of saline soils. The obtained data can be used to enhance and achieve high productivity of forage grasses and to restore the productivity of saline lands and use them for agricultural purposes. Conclusions. Adaptability to the saline soil and the productivity of forage grasses differ according to biological characteristics and extent soil salinity and ecological conditions.