0000000000330632
AUTHOR
Māris Laiviņš
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…
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…
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…
EUNIS Habitat Classification: Expert system, characteristic species combinations and distribution maps of European habitats
Aim The EUNIS Habitat Classification is a widely used reference framework for European habitat types (habitats), but it lacks formal definitions of individual habitats that would enable their unequivocal identification. Our goal was to develop a tool for assigning vegetation-plot records to the habitats of the EUNIS system, use it to classify a European vegetation-plot database, and compile statistically-derived characteristic species combinations and distribution maps for these habitats. Location Europe. Methods We developed the classification expert system EUNIS-ESy, which contains definitions of individual EUNIS habitats based on their species composition and geographic location. Each ha…