Similar to soils, tree stems emit and consume nitrous oxide (N2O) from the atmosphere. Although tree leaves dominate tree surface area, they have been completely excluded from field N2O flux measurements and therefore their role in forest N2O exchange remains unknown. We explored the contribution of leaf fluxes to forest N2O exchange. We determined the N2O exchange of mature European beech (Fagus sylvatica) stems and shoots (i.e., terminal branches) and of adjacent forest floor, in a typical temperate upland forest in Germany. The beech stems, and particularly the shoots, acted as net N2O sinks (-0.254 ± 0.827 μg N2O m-2 stem area h-1 and -4.54 ± 1.53 μg N2O m-2 leaf area h-1, respectively), while the forest floor was a net source (2.41 ± 1.08 μg N2O m-2 soil area h-1). The unstudied tree shoots were identified as a significant contributor to the net ecosystem N2O exchange. Moreover, we revealed for the first time that tree leaves act as substantial N2O sinks. Although this is the first study of its kind, it is of global importance for the proper design of future flux studies in forest ecosystems worldwide. Our results demonstrate that excluding tree leaves from forest N2O flux measurements can lead to misinterpretation of tree and forest N2O exchange, and thus global forest greenhouse gas flux inventories.

• Klíčová slova
• Exchange, Fagus sylvatica, Forest floor, Greenhouse gas, Tree leaves, Tree stem,
• MeSH
• buk (rod) * metabolismus   MeSH
• látky znečišťující vzduch * analýza   MeSH
• lesy MeSH
• listy rostlin metabolismus   MeSH
• monitorování životního prostředí MeSH
• oxid dusný * analýza   metabolismus   MeSH
• výhonky rostlin metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Německo MeSH
• Názvy látek
• látky znečišťující vzduch * MeSH
• oxid dusný * MeSH

Trees are known to be atmospheric methane (CH4 ) emitters. Little is known about seasonal dynamics of tree CH4 fluxes and relationships to environmental conditions. That prevents the correct estimation of net annual tree and forest CH4 exchange. We aimed to explore the contribution of stem emissions to forest CH4 exchange. We determined seasonal CH4 fluxes of mature European beech (Fagus sylvatica) stems and adjacent soil in a typical temperate beech forest of the White Carpathians with high spatial heterogeneity in soil moisture. The beech stems were net annual CH4 sources, whereas the soil was a net CH4 sink. High CH4 emitters showed clear seasonality in their stem CH4 emissions that followed stem CO2 efflux. Elevated CH4 fluxes were detected during the vegetation season. Observed high spatial variability in stem CH4 emissions was neither explicably by soil CH4 exchange nor by CH4 concentrations, water content, or temperature studied in soil profiles near each measured tree. The stem CH4 emissions offset the soil CH4 uptake by up to 46.5% and on average by 13% on stand level. In Central Europe, widely grown beech contributes markedly to seasonal dynamics of ecosystem CH4 exchange. Its contribution should be included into forest greenhouse gas flux inventories.

• Klíčová slova
• CH4 flux, European beech, emission, seasonal dynamics, soil, temperate montane forest, tree stem, uptake,
• MeSH
• buk (rod) * MeSH
• ekosystém MeSH
• lesy MeSH
• methan MeSH
• oxid uhličitý MeSH
• půda * MeSH
• stromy MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• methan MeSH
• oxid uhličitý MeSH
• půda * MeSH

• Klíčová slova
• FTIR, gas chromatograph, greenhouse gas, interference, methane (CH4) flux, nitrous oxide flux, tree stem gas exchange, volatile organic compound (VOCs),
• MeSH
• deštný prales MeSH
• methan MeSH
• oxid dusný * MeSH
• oxid uhličitý MeSH
• spektroskopie infračervená s Fourierovou transformací MeSH
• stromy MeSH
• těkavé organické sloučeniny * MeSH
• Publikační typ
• dopisy MeSH
• komentáře MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Réunion MeSH
• Názvy látek
• methan MeSH
• oxid dusný * MeSH
• oxid uhličitý MeSH
• těkavé organické sloučeniny * MeSH

Trees are known to emit methane (CH4 ) and nitrous oxide (N2 O), with tropical wetland trees being considerable CH4 sources. Little is known about CH4 and especially N2 O exchange of trees growing in tropical rain forests under nonflooded conditions. We determined CH4 and N2 O exchange of stems of six dominant tree species, cryptogamic stem covers, soils and volcanic surfaces at the start of the rainy season in a 400-yr-old tropical lowland rain forest situated on a basaltic lava flow (Réunion Island). We aimed to understand the unknown role in greenhouse gas fluxes of these atypical tropical rain forests on basaltic lava flows. The stems studied were net sinks for atmospheric CH4 and N2 O, as were cryptogams, which seemed to be co-responsible for the stem uptake. In contrast with more commonly studied rain forests, the soil and previously unexplored volcanic surfaces consumed CH4 . Their N2 O fluxes were negligible. Greenhouse gas uptake potential by trees and cryptogams constitutes a novel and unique finding, thus showing that plants can serve not only as emitters, but also as consumers of CH4 and N2 O. The volcanic tropical lowland rain forest appears to be an important CH4 sink, as well as a possible N2 O sink.

• Klíčová slova
• basaltic lava flows, cryptogams, methane flux, nitrous oxide flux, soil, tree stem, tropical lowland rain forest, uptake,
• MeSH
• deštný prales MeSH
• lesy MeSH
• methan MeSH
• oxid dusný * MeSH
• oxid uhličitý MeSH
• půda MeSH
• stromy * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Réunion MeSH
• Názvy látek
• methan MeSH
• oxid dusný * MeSH
• oxid uhličitý MeSH
• půda MeSH

The role of trees in the nitrous oxide (N2O) balance of boreal forests has been neglected despite evidence suggesting their substantial contribution. We measured seasonal changes in N2O fluxes from soil and stems of boreal trees in Finland, showing clear seasonality in stem N2O flux following tree physiological activity, particularly processes of CO2 uptake and release. Stem N2O emissions peak during the vegetation season, decrease rapidly in October, and remain low but significant to the annual totals during winter dormancy. Trees growing on dry soils even turn to consumption of N2O from the atmosphere during dormancy, thereby reducing their overall N2O emissions. At an annual scale, pine, spruce and birch are net N2O sources, with spruce being the strongest emitter. Boreal trees thus markedly contribute to the seasonal dynamics of ecosystem N2O exchange, and their species-specific contribution should be included into forest emission inventories.

• MeSH
• atmosféra chemie   MeSH
• ekosystém * MeSH
• methan metabolismus   MeSH
• oxid dusný metabolismus   MeSH
• oxid uhličitý metabolismus   MeSH
• půda chemie   MeSH
• roční období * MeSH
• stonky rostlin metabolismus   MeSH
• stromy fyziologie   MeSH
• tajga * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Finsko MeSH
• Názvy látek
• methan MeSH
• oxid dusný MeSH
• oxid uhličitý MeSH
• půda MeSH

This study was conducted to examine differences between self- and proxy ratings of activities in daily living (ADL) in nursing home residents and to compare them with actual performance. An impact of cognitive status on these ratings was also determined. Data were obtained from 164 dyads of nursing home residents (self-ratings) and their professional care providers (proxy ratings). Statistical procedures included t tests, intraclass correlations, Pearson's correlations, analysis of variance (ANOVA) and ROC curves. Paired t test provided evidence that residents in general overestimated their abilities for all ADLs (p < .01 in all cases), but a substantial subset of 54 residents, with mean MMSE of 18, agreed with their care providers. The mean MMSE score of those who overestimated their abilities was 13 (N = 57). The ANOVA revealed that greater rating differences were associated with more severe cognitive impairment (MMSE, F = 9.93, p < .001). Proxy ratings of walking were not significantly different from actual performances (p = .145), while self-ratings overestimated it (p < .001). Although residents in general overestimated their ADL abilities and results of comparison with actual performance indicated that proxies may be closer to the actual status in this population, a considerable number of those with milder cognitive impairment were able to assess their ADLs with reasonable accuracy.

• Klíčová slova
• ADL, Agreement, Differences, Nursing home residents, Proxy reports, Self-reports,
• Publikační typ
• časopisecké články MeSH

Late life deterioration of functional status is associated with adverse health outcomes and increased cost of care. This trial was conducted to determine whether dance-based intervention could reverse functional decline among nursing home (NH) residents. A total of 189 residents of seven NHs in the Czech Republic were randomly assigned to intervention and control groups. More detailed data were collected in a subsample of 52 participants. Intervention consisted of 3-month dance-based exercise. Functional status was assessed by the get-up-and-go test, basic activities of daily living (ADL), instrumental activities of daily living (IADL), and senior fitness tests (SFTs). Participants in the control group experienced a significant decline in get-up-and-go test, IADL, and in four of the six SFTs. The intervention proved to be effective in preventing this deterioration and improved chair stand test and chair sit-and-reach test. The findings indicate that a relatively simple dance-based exercise can slow down deterioration of functional status in NH residents.

• Klíčová slova
• dance, functional decline, nursing homes, older adults, prevention,
• MeSH
• činnosti denního života * MeSH
• cvičení fyziologie   MeSH
• domovy pro seniory MeSH
• geriatrické hodnocení MeSH
• lidé MeSH
• lineární modely MeSH
• motorické dovednosti fyziologie   MeSH
• pečovatelské domovy MeSH
• psychomotorický výkon fyziologie   MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• terapie tancem metody   MeSH
• úrazy pádem prevence a kontrola   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• multicentrická studie MeSH
• práce podpořená grantem MeSH
• randomizované kontrolované studie MeSH
• Geografické názvy
• Česká republika MeSH

Naturally produced by microbial processes in soil, nitrous oxide (N2O) is an important greenhouse gas contributing to climate change. Accordingly, there is a need to accurately quantify the capability of forest ecosystems to exchange N2O with the atmosphere. While N2O emissions from soils have been well studied, trees have so far been overlooked in N2O inventories. Here, we show that stems of mature beech trees (Fagus sylvatica) may act as a substantial sink of N2O from the atmosphere under conditions of soils consuming N2O. Consistent consumption of N2O by all stems investigated (ranging between -2.4 and -3.8 µg m-2 h-1) is a novel finding in contrast to current studies presenting trees as N2O emitters. To understand these fluxes, N2O exchange of photoautotrophic organisms associated with beech bark (lichens, mosses and algae) was quantified under laboratory conditions. All these organisms were net N2O sinks at full rehydration and temperature of 25 °C. The consumption rates were comparable to stem consumption rates measured under field conditions. Cryptogamic stem covers could be a relevant sink of N2O in European beech forests.

• MeSH
• autotrofní procesy MeSH
• buk (rod) metabolismus   MeSH
• oxid dusný metabolismus   MeSH
• oxid uhličitý metabolismus   MeSH
• půda MeSH
• půdní mikrobiologie * MeSH
• skleníkové plyny metabolismus   MeSH
• stromy metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Evropa MeSH
• Názvy látek
• oxid dusný MeSH
• oxid uhličitý MeSH
• půda MeSH
• skleníkové plyny MeSH

Boreal forests comprise 73% of the world's coniferous forests. Based on forest floor measurements, they have been considered a significant natural sink of methane (CH4) and a natural source of nitrous oxide (N2O), both of which are important greenhouse gases. However, the role of trees, especially conifers, in ecosystem N2O and CH4 exchange is only poorly understood. We show for the first time that mature Scots pine (Pinus sylvestris L.) trees consistently emit N2O and CH4 from both stems and shoots. The shoot fluxes of N2O and CH4 exceeded the stem flux rates by 16 and 41 times, respectively. Moreover, higher stem N2O and CH4 fluxes were observed from wet than from dry areas of the forest. The N2O release from boreal pine forests may thus be underestimated and the uptake of CH4 may be overestimated when ecosystem flux calculations are based solely on forest floor measurements. The contribution of pine trees to the N2O and CH4 exchange of the boreal pine forest seems to increase considerably under high soil water content, thus highlighting the urgent need to include tree-emissions in greenhouse gas emission inventories.

• MeSH
• borovice lesní chemie   MeSH
• methan analýza   metabolismus   MeSH
• oxid dusný analýza   metabolismus   MeSH
• půda chemie   MeSH
• skleníkový efekt MeSH
• tajga * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• methan MeSH
• oxid dusný MeSH
• půda MeSH