Mycobiota of Fine Roots of Pseudotsuga menziesii Introduced to the Native Forest Environment

The mycobiota of the fine roots of Pseudotsuga menziesii were studied as a measure of the adaptation of this alien species to new soil and climatic conditions. We hypothesized that after approximately 130 years of growth in a given habitat, the fungal community colonizing the fine roots of introduced trees would resemble the biota of Pinus sylvestris and Fagus sylvatica in surrounding stands of similar age and site conditions. The genetic material isolated from the fine roots was subjected to metagenomic analysis. We recorded 33, 97 and 95 OTUs exclusively from root samples of Douglas fir, beech and pine, respectively; 124 were common to all sample types. The biota from the roots of P. menziesii featured a less diverse taxonomic composition and were characterized by the highest proportion of symbiotrophs (71.8%) versus saprothrophs (5.6%) and pathogens (0.24%). Some fungal taxa (19) in the roots of P. menziesii were common with the biota in the roots of other adjacent trees, while some (7) were unique to Douglas fir. Our results indicate a locally differentiated strategy of naturalness of fungi inhabiting soil and roots of P. menziesii, although 130 years have passed since the introduction of the species.

Epiphytic lichen cover of collection trees of arboretum of the Botanical Garden of Petrozavodsk State University

At present, 264 species of lichens and allied fungi have been recorded for the territory of the BotanicalGarden of Petrozavodsk State University (Republic of Karelia) and 112 species have been found in its arboretum, wheremore than 200 species of introduced trees grow. The paper presents the results of studying the features of the epiphyticlichen cover of the collection trees of the arboretum of the Botanical Garden of PetrSU (Republic of Karelia). Results of thestudy are based on 1662 descriptions of the epiphytic lichen cover on 209 trees of coniferous species and 1150 descriptions –on 143 deciduous introduced species.The average total projective cover of lichens on the trunks of the studied coniferous introduced species reaches 18 % atthe trunk base, and 19 % – at a height of 130 cm above the ground. The number of species in the descriptions of epiphyticlichen cover varies from 0 to 12 (0.8 in average). The highest values of the projective cover of lichens and the numberof species in the descriptions were observed on the trunks of conifers of the genus Pinus, the lowest – on the trunks oftrees of the genus Thuja. The average total projective cover of lichens on the trunks of the studied deciduous introducedspecies was 8 % at the base, and 25 % – at a height of 130 cm above the ground. The number of species in the descriptionvaries from 0 to 9 (1.0 in average). The highest values of the projective cover of lichens and the number of species in thedescription are noted on the trunks of the genus Quercus, the lowest – on the trunks of trees of the genus Ulmus. Collectiontrees of arboretum tree represent a model object for observing the features of the formation of the epiphytic lichen cover

Soils classified in the Arboretum Mlyňany, Slovakia

Successful adaptation of introduced trees requires providing appropriate conditions for their growth and life. In this context, our study aim was a soil survey in the Arboretum Mlyňany, on the basis of which the soils could be classified. Detailed soil investigations were done at seventeen sites under dense monocultures of trees and the grassland. For each site, there was dug one soil pit, near which there were made three soil bores. Over most area of the locality, the prevailing soil-forming substrates were decalcified loess and silt, with gravelly patches, with prevailing medium soil texture, and acid to slightly acid pH. Based on the morphological features and the results concerning the physical and chemical soil properties, seven quality-degrees of soil cover were classified. The lowest-quality was recognised in Fragic Stagnic Retisol, in the highest-situated, east part of Arboretum, and also in the central part of the Ambrozy’s park under Thuja plicata, where there was discerned also low quality Albic Stagnic Luvisol. The most area east of the manor house is covered with Stagnic Cutanic Luvisol (the North American and East Asian area with Stagnic Cutanic Luvisol (Anthric)). North of the manor, on a slight slope of the North American area was found a Cutanic Luvisol (Anthric). West of the manor, the terrain evenly declines, and there has been developed Luvic Chernozem, whose cultivated form, Luvic Chernozem (Anthric), was determined in the East Asian area.

Characteristics of physical properties in soil profiles under selected introduced trees in the Nature Reserve Arboretum Mlyňany, Slovakia

The relationship between introduced trees roots and soils in which they grow is the most important factor influencing the adaptation, growth and health of these trees. Therefore, the objective of this study was to identify which physical soil properties enhance or limit the vitality of the studied introduced trees in the Arboretum Mlyňany. Soil properties were studied in seven soil profiles under dense monocultures of Chamaecyparis lawsoniana, Liriodendron tulipifera, Juniperus Chinensis, Thuja orientalis, Thuja plicata, Picea orientalis and Pinus nigra. The results showed that all stagnic horizons had exceeded the limit values of total porosity and bulk density, hence these horizons were compacted. Based on the soil and climatic requirements of the examined trees we conclude that the soil properties of their sites in arboretum are suitable for: Chamaecyparis lawsoniana, Liriodendron tulipifera, Thuja orientalis and Pinus nigra. Nevertheless, physical properties in profiles under Picea orientalis and Juniperus Chinensis do not permit rapid drainage of water, what is unfavourable for healthy development of these two species; while Thuja plicata demanding high moisture supply is grown on soil with high coarse porosity, a prerequisite of fast rainwater drainage. However, since none of the studied introduced trees had suffered from physiological disorders or diseases, they may be declared acclimatized well in the soil-climate conditions described in this study.

Collateral benefit: unconscious conservation of threatened plant species

In Europe, the conservation of rare or threatened plant species (ROTS) largely involves the manipulation of anthropogenic disturbance regimes rather than the mitigation of human-induced threatening processes, as has been the case in Australia. In Tasmania, there are many ROTS, especially those of the depleted and stock-grazed grasslands and grassy woodlands, which survive because, unconscious of the needs of ROTS, people have disturbed land in ways that suit their life-cycle requirements. Such species are found in quarries, in borrow pits, in scrapes, on roadsides, on track edges, on old roads, under introduced trees, in heavily grazed native pastures, in regenerating clearfell coupes and on mown ground. They are disturbance-dependent species, usually with poor competitive abilities. Many cannot survive stock-grazing. Unconscious conservation of these species needs to become conscious, in the European manner. Spatial heterogeneity in disturbance regimes is important for maintaining this set of species, whereas temporal heterogeneity is likely to lead to their doom.

Do Rhizobia Infect Roots of American Yellowwood and Japanese Pagodatree?

Knowing whether leguminous trees have the potential to nodulate after infection by rhizobial bacteria is important for managing nitrogen (N) applications during tree production and for culture in the landscape. Although 98% of studied species in the Papilionoideae nodulate, the nodulation status of two tree species in this subfamily is uncertain. Cladrastis kentukea (Dum.-Cours.) Rudd (American yellowwood) did not form nodules during inoculation studies in 1939 and 1992. Nodules were observed on mature Sophora japonica L. (Japanese pagodatree) in Japan and Hawaii in the 1940s, but compatible rhizobia reportedly isolated in Japan are no longer held in bacterial collections. Our objective was to verify further that American yellowwood does not nodulate and to confirm reports that Japanese pagodatree does nodulate. Rhizobia that infect many plant hosts, soil samples and rhizobial isolates from other Sophora spp., and soil samples from mature American yellowwood and Japanese pagodatree were used to inoculate 5-day-old seedlings of American yellowwood, Japanese pagodatree, and control species. Soil from indigenous and introduced trees in the continental United States, Hawaii, Japan, and China was used. Inoculated and uninoculated plants were grown for 7 weeks in sterile Leonard jars or clay pots containing perlite and irrigated with sterile, N-free Hoagland's solution. No inoculation treatment elicited nodulation of American yellowwood or Japanese pagodatree. Our results provide additional evidence that American yellowwood lacks that capacity to nodulate and cast further doubt on nodulation of Japanese pagodatree.

Bird assemblages in a small public reserve and adjacent residental area at Wollongong

A total of 8262 birds of 57 species was counted in a degraded public reserve and adjacent residential area during 61 paired transects in 1990. Most of the reserve was remnant wet sclerophyll forest (5 ha) and subtropical rainforest (0.4 ha), whereas a variety of mature native and introduced trees and shrubs were present in the 55-year-old suburb. Species evenness was similar in the habitats of the reserve and residental area but not species richness, number of individuals or composition of the avifauna. In all seasons, the reserve was richer in species but poorer in absolute numbers of birds. Thirteen native species were reserve specialists, six species (five introduced) were suburb specialists and 17 species showed only slight habitat preference. Excluding silvereyes, which showed little preference for either habitat, there were twice as many regularly occurring species that preferred to use the reserve rather than the residential area but only half the number of individuals. Nine specialist species are at risk of local extinction because their populations in the reserve are critically small [range: 80 (brown gerygone, Gerygone mouki) to 5 birds (eastern whipbird, Psophodes olivaceus)]. Seventeen species have become locally extinct since Europeans arrived in 1816. Conservation of the avifauna is discussed.