Influence of De-Icing Salt on K Supply and Street Trees Ecological Status in Riga, Latvia

The study was conducted to evaluate the toxic effect of soil and plant pollution with Na and Cl− on K supply and ecological condition of the street trees (Tilia × vulgaris H.) in Riga during 2005 and 2007. The results revealed that the ecological status of street trees could be characterized as seriously injured due to high concentrations of Na and Cl− in soil (maxNa 1,568.1 mg/kg; maxCl 744.9 mg/kg) and lime leaves (maxNa 1.93%; maxCl 3.00%). The concentrations of Na and Cl− in lime leaves demonstrated a marked tendency to increase during summer, while the concentrations of K in leaves decreased (min. 0.15%). There were close correlations between the concentration of Na and Cl− in lime lea…

Chemical Composition of Scots Pine Bark as a Bioindicator of Environmental Quality in Riga, Latvia / Priežu Mizu ķīmiskais Sastāvs Kā Vides Stāvokļa Bioindikators Rīgā (Latvija)

Abstract The chemical composition of pine bark was used for the determination of environmental quality in Rīga. Bark samples were collected at 54 sites in Rīga differing in vegetation and building area characteristics (urban forests, parks and cemeteries, dwelling houses, and streets and railway zones) and at 52 sites from rural areas in Latvia (background level). Concentrations of Ca, Mg, Na, K, Fe, Mn, Zn, Ni, Cu, Cd, Pb, and pH was determined in the samples. The results showed significantly higher concentrations of chemical elements in pine bark collected in Rīga, compared to background levels: Fe and Cu concentrations three times higher, and other elements - up to 1.8 times. The highest…

Preliminary Studies on Microbial Biomass and the Microarthropod Community as Soil Health and Quality Indicators in Urban Grasslands, Rīga as an Example / Sākotnējie Pētījumi Par Augsnes Mikrobiālo Biomasu Un Augsnes Sīkposmkāju Sabiedrībām Kā Augsnes Veselības Un Kvalitātes Indikatoriem Rīgas Pilsētas Urbānajos Zālājos

Antropogēnais piesārņojums tiek uzskatīts par vienu no galvenajiem faktoriem, kas ietekmē augsni pilsētās. 2014. gadā uzsākts pētījums par augsnes kvalitāti urbānajos zālājos Rīgā. Pētījuma mērķis bija noteikt augsnes mikrobiālo biomasu un augsnes sīkposmkāju kopienu dažādu zālāju augsnēs Rīgā un izvērtēt iespējas tos izmantot kā pilsētvides augsnes veselības un kvalitātes rādītājus. Rīgā atšķirīgos pilsētas rajonos tika izvēlēti seši dažāda lieluma parauglaukumi ar atšķirīgām vietas apbūves īpatnībām, ielu un dzelzceļu tīkla blīvumu un transporta noslogojumu, vidi piesārņojošo objektu iespējamo ietekmi, kā arī citām, urbānu vidi raksturojošām īpatnībām. Substrāta izraisītas elpošanas metod…

Comparison of neophyte communities of Robinia pseudoacacia L. and Acer negundo L. in the eastern Baltic Sea region cities of Riga and Kaunas

Abstract In this study, we examined the species composition of neophyte communities of Robinia pseudoacacia and Acer negundo and compared the site conditions of the urban environment of two cities—Riga and Kaunas. Eighty-five plots of A. negundo and R. pseudoacacia communities were selected. Within each plot, all of the vascular plant species were recorded, and their abundance was estimated in 2014. Composite soil samples of the 0–10 cm mineral topsoil were collected for the estimation of the soil chemical properties at nine systematically distributed points in each sample plot. The soil pH KCL , exchangeable bases, total nitrogen, total organic matter, C/N ratio, and concentrations of the …

Pest Plant Score of Alien Robinia Pseudoacacia in Rīga (Latvia) and Kaunas (Lithuania) / Svešzemju Sugas Robinia Pseudoacacia Invazitātes Novērtējums Rīgā (Latvija) Un Kauņā (Lietuva)

Abstract Robinia pseudoacacia is an alien tree species that has wide distribution in green areas of Rīga and Kaunas. In recent years, the spread and invasion of this species was observed. The aim of this study was to determine the relative importance of invasiveness of R. pseudoacacia in Rīga and Kaunas. The degree of species invasion was estimated by applying the Pest Plant Prioritization Process, which is based on the Analytic Hierarchy Process method. The results showed that the invasive degree of R. pseudoacacia was near medium (0.4); the present compared to potential distribution rating was medium (0.57) and the social, environmental and economic impact score was very low (0.17). The F…

Toxic impact of the de-icing material to street greenery in Riga, Latvia

Abstract There is little information on the ecological composition of snow on roads as well as the toxic effect of de-icing salt on the ecological status of the street trees ( Tilia x vulgaris H.) in Latvia. Tilia x vulgaris is one of the most widespread tree species of street greenery in the boreo-nemoral zone – in Central, Northern and Eastern Europe. This investigation was done to find out the accumulation of de-icing salt (main elements – sodium and chlorine) in the snow–soil–plant system of street greenery in the central part of Riga (2004–2005), in order to reveal the toxic effect on the ecological status of the street trees ( Tilia x vulgaris ). Snow, soil and leaf samples were colle…

Nemoralisation of Pinus sylvestris and Picea abies Forest Stands in the Hemi-Boreal Zone: A Case Study from Latvia

Abstract At the beginning of the 21st century, in extensively managed mature and over-mature conifer stands (Pinus sylvestris and Picea abies) in Latvia, establishment of native deciduous broad-leaved (Acer platanoides, Tilia cordata, Quercus robur and Ulmus laevis), as well as alien broad-leaved species (Acer pseudoplatanus and Tilia platyphyllos) has been observed. The establishment of deciduous broad-leaved species in coniferous stands is a process known as nemoralisation of coniferous stands, which is characterised by a large number of seedlings of broad-leaved species, young trees and the formation of a subcanopy layer in stands. Based on the age measurements of individuals of broad-le…

The spread, intensity and invasivenessof the Acer negundo in Riga and Kaunas

DYNAMICS OF SOIL NUTRIENT STATUS OF HIGHBUSH BLUEBERRY IN LATVIA, 2006-2017

In Latvia, the first commercial highbush blueberry (Vaccinium corymbosum L.) plantings have been established on a few hectares at the end of the 1990th. Since then, a remarkable growth has noticed and today the total cultivated area reaches 280 hectares. An increasing market demand for fresh and processed berries provides a future upward trend in the development of blueberry crop in Latvia. In general, blueberry is a highly specialized crop that has definite soil agrochemical and climatic requirements. There are two main soil types used for blueberry cultivation in Latvia: well-drained acid sandy soils with high organic matter content and sphagnum peat soils. Evaluation and management of pl…

Salinity-induced responses and resistance in Trifolium repens L.

Abstract White clover ( Trifolium repens L.) is a commonly cultivated legume with good ground cover potential often used with companion grass species in urban grassed areas. The effect of increased soil salinity on plant growth is an urgent problem in cities where NaCl is used as a de-icing material. The aim of this research was to examine the effect of different salinity levels and K supply-induced responses and tolerance in the T. repens L. variety ‘Daile’, a variety which is used in urban greenery. To analyze the impact of increased soil salinity and the antagonistic effect of K, the effect of gradually increasing NaCl (0, 20, 40, 60, 80, 100 mM) and K (+0, +100, +200, +300 mg/L) levels …

A study of chemical characteristics of soil in relation to street trees status in Riga (Latvia)

Abstract The chemical composition of soil and appropriate supply of nutrients are very important factors for normal plant growth and development. Lime tree ( Tilia x vulgaris H.), is a popular tree species used for urban landscaping in Europe. However, there is little information on the chemical element concentrations available to and recommended for T. x vulgaris in urban soils. The objectives of this study were: (1) to investigate the amount of nutrients, de-icing salts and heavy metals available for uptake by trees in the city centre on a seasonal scale; and (2) to assess the relationship between the vitality of T. x vulgaris and soil chemistry. The research was carried out in five stree…

ASSESSMENT OF THE IMPACT OF VERMICOMPOST AND PEAT EXTRACTS ON NUTRIENT ACCUMULATION IN TUBERS AND POTATO YIELD

Investigations on the potential beneficial effect of humic substances on crop plant cultivation under extremely diverse soil and climatic conditions is of global character, thereby knowledge obtained on the basis of local investigations are of great importance world-wide. The aim of the research was to evaluate the effect of different application methods (seed tuber treatment and foliar application) of commercially-produced peat and vermicompost extracts on nutrient uptake in tubers and yield of potato ( Solanum tuberosum L.) using field experiments in organic farming system with potato variety ‘Borodjanskij Rozovij’. The tested extracts from the organic products included: peat extract (K45…

Salt accumulation and effects within foliage of Tilia × vulgaris trees from the street greenery of Riga, Latvia

International audience; Green infrastructures within sprawling cities provide essential ecosystem services, increasingly undermined by environmental stress. The main objective in this study was to relate the allocation patterns of NaCl contaminants to injury within foliage of lime trees mechanistically and distinguish between the effects of salt and other environmental stressors. Using field material representative of salt contamination levels in the street greenery of Riga, Latvia, the contribution of salt contaminants to structural and ultrastructural injury was analyzed, combining different microscopy techniques. On severely salt-polluted and dystrophic soils, the foliage of street lime …