Kallioperä ja maalaji vaikuttavat hirvivahinkojen määrään

201

Effects of bedrock and surficial deposit composition on moose damage in young forest stands in Finnish Lapland

201

UHPLC-ESI/TOFMS Determination of Salicylate-like Phenolic Gycosides in Populus tremula Leaves

Associations of salicylate-like phenolic glycosides (PGs) with biological activity have been reported in Salix and Populus trees, but only for a few compounds, and in relation to a limited number of herbivores. By considering the full diversity of PGs, we may improve our ability to recognize genotypes or chemotype groups and enhance our understanding of their ecological function. Here, we present a fast and efficient general method for salicylate determination in leaves of Eurasian aspen that uses ultra-high performance liquid chromatography-electrospray ionization/time-of-flight mass spectrometry (UHPLC-ESI/TOFMS). The time required for the liquid chromatography separations was 13.5 min per sample, compared to around 60 min per sample for most HPLC protocols. In leaf samples from identical P. tremula genotypes with diverse propagation and treatment histories, we identified nine PGs. We found the compound-specific mass chromatograms to be more informative than the UV-visible chromatograms for compound identification and when quantitating samples with large variability in PG content. Signature compounds previously reported for P. tremoloides (tremulacin, tremuloidin, salicin, and salicortin) always were present, and five PGs (2'-O-cinnamoyl-salicortin, 2'-O-acetyl-salicortin, 2'-O-acetyl-salicin, acetyl-tremulacin, and salicyloyl-salicin) were detected for the first time in P. tremula. By using information about the formic acid adduct that appeared for PGs in the LTQ-Orbitrap MS environment, novel compounds like acetyl-tremulacin could be tentatively identified without the use of standards. The novel PGs were consistently either present in genotypes regardless of propagation and damage treatment or were not detectable. In some genotypes, concentrations of 2'-O-acetyl-salicortin and 2'-O-cinnamoyl-salicortin were similar to levels of biologically active PGs in other Salicaceous trees. Our study suggests that we may expect a wide variation in PG content in aspen populations which is of interest both for studies of interactions with herbivores and for mapping population structure

A comparative analysis of phenylpropanoid metabolism, N utilization, and carbon partitioning in fast- and slow-growing Populus hybrid clones

The biosynthetic costs of phenylpropanoid-derived condensed tannins (CTs) and phenolic glycosides (PGs) are substantial. However, despite reports of negative correlations between leaf phenolic content and growth of Populus, it remains unclear whether or how foliar biosynthesis of CT/PG interferes with tree growth. A comparison was made of carbon partitioning and N content in developmentally staged leaves, stems, and roots of two closely related Populus hybrid genotypes. The genotypes were selected as two of the most phytochemically divergent from a series of seven previously analysed clones that exhibit a range of height growth rates and foliar amino acid, CT, and PG concentrations. The objective was to analyse the relationship between leaf phenolic content and plant growth, using whole-plant carbon partitioning and N distribution data from the two divergent clones. Total N as a percentage of tissue dry mass was comparatively low, and CT and PG accrual comparatively high in leaves of the slow-growing clone. Phenylpropanoid accrual and N content were comparatively high in stems of the slow-growing clone. Carbon partitioning within phenylpropanoid and carbohydrate networks in developing stems differed sharply between clones. The results did not support the idea that foliar production of phenylpropanoid defence chemicals was the primary cause of reduced plant growth in the slow-growing clone. The findings are discussed in the context of metabolic mechanism(s) which may contribute to reduced N delivery from roots to leaves, thereby compromising tree growth and promoting leaf phenolic accrual in the slow-growing clone

Close and distant : contrasting the metabolism of two closely related subspecies of Scots pine under the effects of folivory and summer drought

Metabolomes, as chemical phenotypes of organisms, are likely not only shaped by the environment but also by common ancestry. If this is the case, we expect that closely related species of pines will tend to reach similar metabolomic solutions to the same environmental stressors. We examined the metabolomes of two sympatric subspecies of Pinus sylvestris in Sierra Nevada (southern Iberian Peninsula), in summer and winter and exposed to folivory by the pine processionary moth. The overall metabolomes differed between the subspecies but both tended to respond more similarly to folivory. The metabolomes of the subspecies were more dissimilar in summer than in winter, and iberica trees had higher concentrations of metabolites directly related to drought stress. Our results are consistent with the notion that certain plant metabolic responses associated with folivory have been phylogenetically conserved. The larger divergence between subspecies metabolomes in summer is likely due to the warmer and drier conditions that the northern iberica subspecies experience in Sierra Nevada. Our results provide crucial insights into how iberica populations would respond to the predicted conditions of climate change under an increased defoliation in the Mediterranean Basin

Digitalisaation tuomat muutokset palkanlaskijan työhön

Tämän tutkimustyyppisen opinnäytetyön tavoitteena oli selvittää, miten digitalisaatio tulee muuttamaan palkanlaskijan työtä ja millaiseksi palkanlaskijan työ muuttuu tulevaisuudessa. Työn aihe oli rajattu koskemaan digitalisaation tuomia muutoksia nimenomaan palkanlaskijan työhön. Työllä ei ollut toimeksiantajaa, vaan se syntyi työn kirjoittajan omasta kiinnostuksesta aihetta kohtaan. Opinnäytetyö valmistui marraskuussa 2022. Työn tietoperustan ensimmäisessä osassa käsiteltiin palkanlaskijan työtä ja yleisimpiä asioita, joita työssä tulee huomioida, jotta saataisiin hyvä kuva siitä, mitä kaikkea palkanlaskijan työhön kuuluu. Tietoperustan toisessa osassa käsiteltiin digitalisaatiota, automaatiota ja robotiikkaa ja myös niiden vaikutuksia palkanlaskentaan. Tietoperustassa käytettiin lähteenä pääasiassa alan kirjallisuutta, mutta myös artikkeleita täydentämään työtä. Tutkimuksen aineisto kerättiin Webropol kyselylomakkeella. Kyselyä jaettiin sosiaalisen median kautta lokakuun 2022 aikana. Kyselyn kohderyhmänä olivat palkanlaskijat ja kyselyyn vastasi yhteensä 50 henkilöä. Tutkimuksessa selvisi, että palkanlaskijan työ tulee muuttumaan enemmän asiantuntijatyöksi. Työssä korostuu tulevaisuudessa yhä enemmän neuvonta ja konsultointi. Työssä tarvitaan tulevaisuudessa parempaa osaamista järjestelmistä ja laajempaa osaamista muistakin osa-alueista kuin palkanlaskennasta

Boron in forest trees and forest ecosystems

This review critically examines the role of boron (B) in forests in view of recent findings on B nutrition and the continuing occurrence of B deficiency. Many perceptions about the role of B in plants and its uptake and mobility have been altered since the last review on B in forest trees in 1990. Now there is evidence for a fundamental role of B in the formation of the pectic structure in primary cell walls in plants, and further roles in membrane function are being explored. In plants, channel-mediated B uptake, active B uptake and B uptake by mycorrhizas have been shown, B transporters have been identified, and B retranslocation has been shown. We explore these findings and their consequences on forest trees and on ecosystems that they dominate. Particular emphasis is placed on B retranslocation and B in mycorrhizal symbiosis, given their importance in trees.Following from impaired development of the primary cell wall in B-deficient trees, disorders in the structural development of organs and whole plants are manifested. This has consequences for tree form, affecting wood quality and productivity. At a stand level, at least part of the value of wood production is lost by the time the deficiency symptoms appear. As symptoms identifying deficiency in many tree species are too easily confused with many other effects, greater use should be made of foliar analysis but this requires establishing robust prognostic values for the trees of interest. There is still no explanation as to why root tip and mycorrhiza development are among the first phenomena to be affected as the B supply decreases. Whether B is required by, or whether it is useful for fungi, is still an open question.Boron remobilisation within trees may be a key factor in the occurrence of forests in areas with very low B availability, as most of the B in the whole stand can be in the standing biomass. The ability to remobilise B varies considerably between species, but we suggest that there is a continuum rather than a strict division to B-retranslocating and non-retranslocating species. Boron output from forest ecosystems with potential for leaching is controlled by adsorption in the soil, which is still poorly understood particularly in soils with abundant organic matter. Increased concentrations of phenolic compounds in B-deficient plants and possibly altered lignin concentration can affect plant defence systems to herbivory and pathogens, and nutrient and carbon release through decomposition. Hence, B nutrition and fertilisation of low-B stands can have implications both to the resistance of trees to biotic stress, as well as influence the cycles of other nutrients and carbon in forests