Nighttime doesn’t stop N2O and CH4 exchange from riparian forest tree stems with the atmosphere

2020 ◽  
Author(s):  
Thomas Schindler ◽  
Katerina Machacova ◽  
Ülo Mander ◽  
Kaido Soosaar
Keyword(s):  
Forest Ecosystems ◽  
Riparian Forest ◽  
Fast Response ◽  
Forest Tree ◽  
Soil Conditions ◽  
Ministry Of Education ◽  
Stem Height ◽  
Night Time ◽  
Sustainability Program ◽  
A Minor

<p>Riparian forest ecosystems have been considered to be a natural source of nitrous oxide (N<sub>2</sub>O) and a natural sink of methane (CH<sub>4</sub>), both of which are important greenhouse gases (GHG) originating from microbiological processes. Wetland trees may also contribute to the GHG exchange by the release of both gases to the atmosphere or uptake therefrom. Recent studies have investigated the role of tree stems, underlining their importance in understanding forest GHG dynamics, focussing on various tree species, soil conditions or seasonal dynamics. However, knowledge about the short-termed day and night-time distributed GHG exchange of tree stems with the atmosphere is still scarce. We studied stem fluxes in a riparian forest ecosystem aiming to investigate the diurnal pattern and predict the potential influence of solar radiation.</p><p>The diurnal flux measurements were performed at 40-year-old grey alder (Alnus incana) forest stand in Estonia with 12-hour interval during July-September 2017 and May-September 2018 (n=16). The exchange of N<sub>2</sub>O and CH<sub>4</sub> was measured from 12 trees at profile height up to 5 m (0.1, 0.8, 1.7, 2.5, 5.0 m) using non-steady state stem chamber systems and gas chromatography. Simultaneously, soil fluxes were automatically quantified using a dynamic chamber system (Picarro 2508); piezometers, automatic groundwater level wells, soil temperature and moisture sensors were installed to determine coherent soil conditions.</p><p>Our preliminary results showed N<sub>2</sub>O and CH<sub>4</sub> emissions from alder tree stems during daytime (4.91 ± 0.15 µg m<sup>-2</sup> h<sup>-1</sup> and 66.38 ± 16.02 µg m<sup>-2</sup> h<sup>-1</sup>, mean ± s.e.) and lower during nighttime (3.65 ± 0.22 µg m<sup>-2</sup> h<sup>-1</sup> and 51.49 ± 13.83 µg m<sup>-2</sup> h<sup>-1</sup>, mean ± s.e.) at 0.1 m stem height, revealing a likely link to solar-driven physiological tree activity. Further, with increasing stem height, the relation of night to daytime fluxes diminished. However, the day-wise variation, including a minor GHG uptake indicates a fast response to changing micro-spatial environmental conditions like water regime in the soil and temperature.</p><p>Our study demonstrates the GHG exchange between tree stems and atmosphere occurs both in day- and night-time, showing slightly higher values in day-time, probably due to the trees’ physiological activities. Furthermore, our findings provide the potential to predict reaction kinetics in future modelling of flux pathways in forest ecosystems.</p><p>Acknowledgement</p><p>This research was supported by the Ministry of Education and Science of Estonia (SF0180127s08 grant), the Estonian Research Council (IUT2-16, PRG-352, and MOBERC20), the Czech Science Foundation (17-18112Y), the Czech National Sustainability Program I (LO1415), and the EcolChange Centre of Excellence, Estonia.</p>

scholarly journals Exploring Curricular Internships in Italy: Towards Entrepreneurial Universities

2016 ◽  
Vol 9 (9) ◽  
pp. 150 ◽  
Author(s):  
Maddalena Della Volpe ◽  
Alfonso Siano ◽  
Agostino Vollero ◽  
Francesca Esposito
Keyword(s):  
Triple Helix ◽  
Learning Experiences ◽  
Minor Role ◽  
Ministry Of Education ◽  
Entrepreneurial Universities ◽  
General Sense ◽  
Policy Makers ◽  
Learning Paths ◽  
A Minor ◽  
Academic Year

<p>This paper presents a database of the curricular internships offered by all Italian universities in different Courses of Studies (CoS), in the light of the challenge faced by university managers in shifting their institutions to a more entrepreneurial mode within a “triple helix approach” that highlights the relation between universities, government and enterprises. We built our database considering University Credits (UCs) attributed during the academic year 2014/15, consulting the websites of the Italian Ministry of Education and the official websites of 91 Italian universities. Although 3139 out of 4428 CoS (70.89%) offer curricular internships, these learning experiences in most scientific areas have a minor role in learning paths. These results also highlight the general sense of mistrust Italian universities place in the entrepreneurial world. The paper should enable university managers and policy makers to evaluate the activities carried out during curricular internships in Italy. The paper also provides useful insights to redefine the CoS offer in Italy. Data could be collected and updated yearly in order to monitor how the scenario is evolving. This paper contends that internships should be placed within the teaching mission in order to have an impact on entrepreneurship.</p>

Effect of the Gabčíkovo Waterworks (Slovakia) on riparian floodplain forest ecosystems in the Danube inland delta: vegetation dynamics and trends

Biologia ◽  
2017 ◽  
Vol 72 (7) ◽  
Author(s):  
Mária Petrášová-Šibíková ◽  
Igor Matečný ◽  
Eva Uherčíková ◽  
Peter Pišút ◽  
Silvia Kubalová ◽  
...  
Keyword(s):  
Species Composition ◽  
Forest Ecosystems ◽  
Supply System ◽  
Floodplain Forest ◽  
Soil Conditions ◽  
Plant Species Composition ◽  
Forest Species ◽  
The Past ◽  
The Impact ◽  
Rare Opportunity

AbstractHuman alteration of watercourses is global phenomenon that has had significant impacts on local ecosystems and the services they provide. Monitoring of abiotic and biotic changes is essential to mitigating long-lasting effects, and the 23-year dataset from the Gabčíkovo Waterworks provided a rare opportunity to assess the impact of groundwater regimes on vegetation. The main aim of this study was to describe the effect of the Gabčíkovo Waterworks on vegetation structure and species composition of the adjacent riparian floodplain forests over the past 23 years. The results are based on studies of three permanent monitoring plots (PMPs) located in the Danube inland delta – two outside (PMP 1 and 3) and one (PMP 2) fully under the influence of the artificial supply system. Our results demonstrate that the Danube inland delta was negatively affected by the Gabčíkovo construction, particularly for sites outside of the artificial supply system. There was a significant decrease in soil moisture and increase in nitrogen at both external PMPs (1 and 3). Alter soil conditions were accompanied by negative changes in plant species composition demonstrated by decreases in the number of typical floodplain forest species that are characteristic for the alliance

scholarly journals Population survey of Milicia excelsa, Pouteria adolfi-fridercii, Antiaris toxicaria and Prunus africana in south and south-western Ethiopia: implications for domesticating and establishing Seed Production Areas

2020 ◽  
Vol 5 (4) ◽  
pp. 153-162
Author(s):  
Mohammed Adefa Seid ◽  
Yigardu Mulatu ◽  
Agena Anjulo ◽  
Semaigzer Ayalew ◽  
Hailu Belay ◽  
...  
Keyword(s):  
Seed Production ◽  
Forest Ecosystems ◽  
Natural Forest ◽  
Target Species ◽  
Stem Height ◽  
Prunus Africana ◽  
Milicia Excelsa ◽  
Western Ethiopia ◽  
Tree Stem

The population dynamics and genetic qualities of stem height and dbh of the populations of Milicia excelsa, Pouteria adolfi-fridercii, Antiaris toxicaria and Prunus africana were assessed and studied in 14 forest ecosystems in south and south-western Ethiopia. A systematic random quadrat sampling technique was employed to identify potential habitat area for selected timber species in south and south-western Ethiopia. So, a total of 10 parallel transect lines were set out across each forest habitat. Milicia excelsa was assessed in four forest ecosystems; Bebeka -Duduka natural forest (45 tree stem ha-1) and Yayu coffee mixed forest (40 tree stem ha-1) appeared to have relatively denser population of M. excelsa compared to the other pilot forests. Similarly, statistically larger stem height (m) is observed in Bebeka-Duduka natural forest (x̅=29.5, SD=4.2) and larger dbh size (cm) in Bebeka 1 coffee mixed forest (x̅=48.5, SD=25.2) at p<0.05. Hence, Bebeka-Duduka natural forest and Bebeka 1 coffee mixed forests are identified for in-situ SPA establishment project of the target species. Pouteria adolfi-fridercii was assessed in eight forest ecosystems; Masha-Gora shewi forest appeared to have dense population of P. adolfi-fridercii (150 tree stem ha-1) followed by Bebeka-Kebereta (80 tree stem ha-1) as compared to the remaining pilot forests. However, statistically larger stem height (m) is scored in Bebeka 2 natural forest (x̅=30.6, SD=2.98) and Bebeka-kebereta forest (x̅=30.0, SD=4.4) and larger dbh size (cm) in Bebeka 2 natural forest (x̅=96.5, SD=19.9) at p<0.05. So, Bebeka 2 natural forest and Bebeka-kebereta forest are identified for SPA establishment project of the target species. Antiaris toxicaria was assessed in two forest ecosystems where both forest habitats appeared to have the same density of Antiaris toxicaria in hectare. Moreover, analyses of mean stem height (cm) of Bebeka 1 forest (x̅=21.4, SD=5.2) and Bebeka-kebereta forest (x̅=22.4, SD=2.7), and mean dbh size (cm) of Bebeka 1 forest (x̅=48, SD=16.4) and Bebeka-kebereta forest (x̅=48, SD=8.2) appeared to have not significantly different at p<0.05. Prunus africana was assessed in five forest ecosystems; Masha-Gora shewi forest appeared to have dense population of Prunus africana (150 tree stem ha-1) followed by Kaho-shemeta forest (130 tree stem ha-1) as compared to the remaining pilot forests. However, statistically larger stem height (m) is scored in Kaho-shemeta natural forest (x̅=31, SD=7.6) and larger dbh (cm) in Masha-Gora shewi forest (x̅=64.7, SD=28.2) at p<0.05. As the result, Kaho-shemeta natural forest and Bonga-Teja-adela forest are identified for establishment of seed production area of the target species in-situ. Hence, while implementing the project of domestication and seed production area establishment in south and south-western Ethiopia, in-situ and ex-situ areas must be selected and delineated in accordance with this preliminary information of the population dynamics and genetic qualities of stem height and diameter at breast height. The survey data generated in this study would bridge the research gap in relation to the population status of the target tree species in the designated area.

scholarly journals Analysis of trophic structure of forest flora in the Oril River valley

2017 ◽  
Vol 18 (3-4) ◽  
pp. 37-50
Author(s):  
B. A. Baranovsky ◽  
I. A. Ivanko ◽  
A. V. Kotovych ◽  
L. A. Karmyzova ◽  
N. O. Roschina
Keyword(s):  
Plant Species ◽  
Forest Ecosystems ◽  
Black Locust ◽  
Vascular Plant ◽  
River Valley ◽  
Forest Vegetation ◽  
Current Status ◽  
Soil Conditions ◽  
Salix Alba ◽  
Common Oak

Biodiversity is important for maintaining of forest ecosystems functioning and in their resistance to anthropo-climatic challenges. Assessment of species diversity and species ecomorphic analysis is the basis for determining their current status, rational use and protection. At the end of the nineteenth century, Belgard A. L. (1950) in his system of ectomorphs using terminology presented by Dekandol (1956) and Warming (1903), had proposed a «trophomorph» category that reflected species relation to soil richness. Analysis of trophomorphs reflects diversity of soil conditions in different biotopes within forest ecosystems. The article gives an analysis on vascular plant trophomorphs distribution in various forest biotopes of Oril river valley. Flora and vegetation surveys in forests of Oril river valley were carried out by A. L. Belgard and T. F. Kirichenko since the 30s of the 20th century. The latest data on forest vegetation state within the Oril river valley were given in the works of Y. Gamulja and V. Manyuk. Generalized bioecological analysis of flora Oril river valley was represented in the monograph of B. Baranovsky, V. Maniuk, I. Ivanko, L. Karmyzova «Flora analysis of the Oril National Park». As is known, edaphic conditions of plant habitats in a first place are determined by soil fertility depending on the plant nutrients availability. Soddy-forest soil on sandy terrace of Oril river valley has a relatively low content of humus and total nitrogen: 2 and 0.04 %. Under these conditions, pine phytocenoses were ocсurred that represented exclusively by artificial plantings. Soils in the depressed area of Oril river floodplain are much richer in humus and nitrogen content (10 and 0.37 %). Here, arboreal and shrubby vegetation is represented by communities with common oak. On the second terrace of Oril river valley, forest vegetation is represented by artificial pine forests. Microcenoses with black locust, amorpha and willow occurred on elevated areas of sandy terrace (arena). In the depressed area of the arena, microcenoses with aspen and birch, aspen, Tatarian maple, amorpha, black locust were occurred additionally to pine communities. In the Oril floodplain, native arboreal and shrubby vegetation is represented mainly by communities with common oak. In depressed areas of the floodplain, microcenoses with white poplar, black poplar, aspen, Tatarian maple, amorpha, willow (Salix alba, S. fragilis), osiery (Salix cinerea, S. triandra),  and alder are fragmentarily occurred. In conditions of elevated areas of the floodplain, 196 vascular plants species were found, and 105 species in depressed areas. On the second terrace, 38 plant species grow on the elevated areas, and 54 species on the depressed ones. Flora includes 45 adventive plant species. In depressed floodplain areas, oligotrophs are represented by 7 species, mesotrophs by 126 species, megatrophs by 50 species, and in elevated areas: 7, 126 and 25 species, respectively. In depressed areas of arena oligotrophs are represented by 4 species, mesotrophs by 29 species, and megatrophs by 11, elevated areas: 7 and 21 species respectively, and megatrophs were absent.

Impact of high daytime air humidity on nutrient uptake and night-time water flux in silver birch, a boreal forest tree species

2017 ◽  
Vol 17 (7) ◽  
pp. 2149-2157 ◽  
Author(s):  
Priit Kupper ◽  
Gristin Rohula ◽  
Liina Inno ◽  
Ivika Ostonen ◽  
Arne Sellin ◽  
...  
Keyword(s):  
Boreal Forest ◽  
Nutrient Uptake ◽  
Tree Species ◽  
Water Flux ◽  
Forest Tree ◽  
Silver Birch ◽  
Air Humidity ◽  
Night Time ◽  
Forest Tree Species

Radon fluxes in tropical forest ecosystems of Brazilian Amazonia: night-time CO2 net ecosystem exchange derived from radon and eddy covariance methods

2004 ◽  
Vol 10 (5) ◽  
pp. 618-629 ◽  
Author(s):  
Christopher S. Martens ◽  
Thomas J. Shay ◽  
Howard P. Mendlovitz ◽  
Daniel M. Matross ◽  
Scott R. Saleska ◽  
...  
Keyword(s):  
Tropical Forest ◽  
Eddy Covariance ◽  
Forest Ecosystems ◽  
Net Ecosystem Exchange ◽  
Night Time ◽  
Brazilian Amazonia

scholarly journals Ectomycorrhizal Fungi: Participation in Nutrient Turnover and Community Assembly Pattern in Forest Ecosystems

Forests ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 453
Author(s):  
Yanjiao Liu ◽  
Xiangzhen Li ◽  
Yongping Kou
Keyword(s):  
Climate Change ◽  
Nutrient Cycling ◽  
Ectomycorrhizal Fungi ◽  
Host Plants ◽  
Forest Ecosystems ◽  
Global Climate ◽  
Soil Conditions ◽  
Fenton Chemistry ◽  
Soil P ◽  
Historical Factors

Ectomycorrhizal fungi (EcMF) are involved in soil nutrient cycling in forest ecosystems. These fungi can promote the uptake of nutrients (e.g., nitrogen (N) and phosphorus (P)) and water by host plants, as well as facilitate host plant growth and resistance to stresses and diseases, thereby maintaining the aboveground primary productivity of forest ecosystems. Moreover, EcMF can acquire the carbon (C) sources needed for their growth from the host plants. The nutrient regulation mechanisms of EcMF mainly include the decay of soil organic matter via enzymatic degradation, nonenzymatic mechanism (Fenton chemistry), and priming effects, which in turn promote C and N cycling. At the same time, EcMF can secrete organic acids and phosphatases to improve the availability of soil P, or increase mycelium inputs to facilitate plant acquisition of P. The spatiotemporal distribution of EcMF is influenced by a combination of historical factors and contemporary environmental factors. The community of EcMF is associated with various factors, such as climate change, soil conditions, and host distribution. Under global climate change, investigating the relationships between the nutrient cycling functions of EcMF communities and their distribution patterns under various spatiotemporal scales is conducive to more accurate assessments of the ecological effects of EcMF on the sustainable development of forest.

Geographical and solar activity variations in the electron temperature of the upper F -region

1965 ◽  
Vol 286 (1407) ◽  
pp. 537-558 ◽  
Keyword(s):  
Electron Temperature ◽  
Electron Density ◽  
Geomagnetic Latitude ◽  
Minor Effect ◽  
Night Time ◽  
Temperature Variations ◽  
Geographical Variations ◽  
Magnetic Shell ◽  
Time Changes ◽  
A Minor

Electron temperature observations obtained in April-July 1962 on the Ariel I satellite have been further analysed by a statistical method. The general increase of electron temperature with latitude (amounting to about 500 degK) and with altitude between 400 and 1200 km, ( ca . 600 degK) previously reported, are confirmed. In addition, the dawn maximum of electron temperature found by other workers, which at the period of these observations is only a minor effect at 40° geomagnetic latitude, is found to become more pronounced near the magnetic equator. The geographical variations of electron temperature are shown to divide into distinct patterns characteristic of noon, dawn and midnight. The dawn pattern consists essentially of a longitude variation in the amplitude of the dawn maximum. All three patterns are closely associated with the geographical variations of electron density, and by examining the detailed correlation of temperature and density it is shown that the temperature variations result from changes in the collisional cooling rate of the electrons. This provides confirmation of the explanation of the dawn maximum suggested by Dalgarno, McElroy & Moffat (1963). Temperature variations due to changes in the far u.v. emission of the sun are considered. By day it is found that the electron temperature increases with 2800 Mc/s solar emission at a rate of (4.6 ± 2.3) degK per flux unit of 10 -22 Wcm -2 s -1 (c/s) -1 , while at night it decreases at a rate of 2.3 ± 2.7 degK/flux unit. Temperature variations in magnetic storms are compared with density enhancements described by Willmore & Henderson (1965). Electron density increases in the storm are always accompanied by a temperature reduction of about 180 degK, the storm-time changes showing a distinct magnetic shell structure. An instance of a temperature increase near the Brazilian geomagnetic anomaly is also given. Finally it is shown that these results lend support to the suggestion of a departure from thermal equilibrium in the night-time ionosphere.

SOIL CONDITIONS OF FOREST VEGETATION GROWTH OF NORTHERN VOLGA

10.12737/3822 ◽  
2014 ◽  
Vol 9 (1) ◽  
pp. 112-116
Author(s):  
Жубрин ◽  
Denis Zhubrin ◽  
Сабиров ◽  
Ayrat Sabirov
Keyword(s):  
Forest Soils ◽  
Forest Ecosystems ◽  
Biological Diversity ◽  
Basic Research ◽  
Economic Assessment ◽  
Forest Vegetation ◽  
Soil Conditions ◽  
Vegetation Growth ◽  
Wide Range ◽  
The Impact

Conducting soil studies are relevant in determining the subordination of forest types and biodiversity of vegetation to soil taxa, in determining the dependence of basic forest stand productivity from soil conditions, in creating a land registry and economic assessment of forest land, in studying the soil evolution of forest plantations under the impact of anthropogenic influences. Soil is the most important environmental factor in shaping the productivity and biodiversity of forest phytocenosis. The study of forest soils is also important in terms of basic research of their genesis, evolution. The article presents the results of research of soil conditions of vegetation growth of forest ecosystems of northern regions of Volga of the Republic of Tatarstan. The main types of forest soils are characterized in the paper. The studied forest formations grow on various soils on genesis and forest vegetation properties: sod-podzol, gray forest, brown forest, brown forest sandy, alluvial meadow, rendziny soil. The granulometric structure of soils varies from sandy to the clay. The well structured soils are formed on loamy layers under forest phytocenosis canopy. Pine and spruce ecosystems have a medi-decomposed litter of moder and multi-moder types; linden, oak, birch and aspen biogeocoenoses have strong-decomposed litter of multi type, that characterizes the intense biological cycle of substances in forest ecosystems. The wide range of place conditions of territories causes the biological diversity of forest vegetation at the level of species and ecosystems.

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