Responses of carbon and nitrogen concentrations in high arctic plants to experimental warming

2001 ◽  
Vol 79 (6) ◽  
pp. 711-718 ◽  
Author(s):  
Anne Tolvanen ◽  
Gregory HR Henry

We studied total carbon (C) and nitrogen (N) concentration in five arctic plant species, Cassiope tetragona (L.) D. Don (evergreen dwarf shrub), Dryas integrifolia Vahl (semi-evergreen dwarf-shrub), Salix arctica Pall. (deciduous, dioecious dwarf shrub), Oxyria digyna (L.) Hill (forb), and Carex stans Drej. (graminoid, sedge), after five growing seasons of experimental increase in temperature. The experiments were established in different habitats along a moisture gradient in a coastal lowland at Alexandra Fiord, Ellesmere Island (79ºN). Sampling was conducted three times during the growing season. The seasonal patterns of C and N concentration were similar across all investigated species, even though the absolute concentrations differed. Nitrogen concentrations were high early in the season during the active growth period but declined later in the season. Warming decreased the N concentration and increased the C/N ratio in the three woody species, whereas N concentrations in the forb and the sedge were not affected. Although not measured directly in our study, the differences in concentrations may be due to the slower response in nutrient uptake and growth in the dwarf shrubs but increased nutrient uptake and growth in the forb and the sedge. Among-site differences were only significant in C concentrations of old tissues of Cassiope tetragona and S. arctica. Male and female S. arctica did not differ in their responses to warming. Differences among plant species in their plastic responses may relate to survival during rapid environmental change. Slow-responding dwarf shrubs may be under increased risk of competition from more responsive and faster growing species, such as forbs and graminoids.Key words: allocation, climate change, dwarf shrub, forb, graminoid, ITEX, Ellesmere Island.

2018 ◽  
Vol 9 (3) ◽  
pp. 167-174
Author(s):  
Dian Ariyanti ◽  
Nurheni Wijayanto ◽  
Iwan Hilwan

Vegetation is one factor that can decrease carbon accumulation in the atmosphere. The diversity of plant species in each land use has different abilities to absorb carbon in the atmosphere. This research was conducted in Pesisir Barat Regency of Lampung Province on 4 (four) types of land use, namely: (1) natural forest in Balai Kencana Resort, Bukit Barisan National Park (2) oil palm plantation in Pekon Marang, (3) coffee plantation in Pekon Suka Mulya, and (4) agroforestry of repong damar in Pekon Pahmungan. This reserach aims to analyze the diversity of plant species and to calculate the potential of plant carbon stock and carbon sequestration (above ground biomass) using alometric equations in various types of land use in Pesisir Barat Regency. The research method was vegetation analysis to learn about the diversity of plant species and calculation of carbon stock using alometric equations. The results showed that the composition of plant species in Bukit Barisan NP found 83 plant species belonging to 37 families, in the palm plantation found 9 plant species belonging to 8 families, in the coffee garden found 17 plant species belonging to 11 families, and in agroforestry of repong damar found 73 plant species belonging to 33 families. The total carbon stock potential was 376.16 ton/ha and carbon sequestrated. 1 257.20 ton/ha with the highest carbon uptake available at repong damar agroforestry site of 901.11 ton/ha.Keywords: aboveground biomass, carbon, diversity, pesisir barat regency


1978 ◽  
Vol 129 ◽  
pp. 1-66
Author(s):  
S Funder

The Holocene stratigraphy in Scoresby Sund is based on climatic change as reflected by fluctuations in fjord and valley glaciers, immigration and extinction of marine molluscs, and the vegetation history recorded in pollen diagrams from five lakes. The histories are dated by C-14, and indirectly by emergence curves showing the patterns of isostatic uplift. From c. 10100-10400 to 9400 yr BP the major fjord glaciers showed oscillatory retreat with abundant moraine formation, the period of the Milne Land Moraines. The vegetation in the ice-free areas was a sparse type of fell field vegetation but with thermophilous elements indicating temperatures similar to the present. From 9400 yr BP the fjord glaciers retreated rapidly in the narrow fjords, the few moraines formed are referred to the Rødefjord stages and indicate topographically conditioned stillstands. At 8000 yr BP the low arctic Betula nana immigrated into the area, and in the period until 5000 yr BP dense dwarf shrub heath grew in areas where it is now absent. In the fjords the subarctic Mytilus edulis and Pecten islandica lived, suggesting a climate warmer than the present. From c. 5000 yr BP the dense dwarf shrub heath began to disappear in the coastal areas, and a 'poor' heath dominated by the high arctic Salix Arctica and Cassiope tetragona expanded. These two species, which are now extremely common, apparently did not grow in the area until c. 6000 yr BP. In lakes in the coastal area minerogenic sedimentation at c. 2800 yr BP, reflecting the general climatic deterioration.


2021 ◽  
Vol 38 ◽  
pp. 00021
Author(s):  
Vera Cheryomushkina ◽  
Evgeniya Talovskaya ◽  
Alexandra Guseva

The structure of 24 species of Thymus and 12 species of Scutellaria was studied using the architectural approach. For the first time, an architectural unit was described, it is a branched sympodial axis. The architectural unit consists of sympodial axes n+1 order, formation shoots, branching shoots, ephemerous shoots. The wide distribution of species and development of species in contrasting habitat conditions is due to the diversity of sympodial axes and shoots that are part of the architectural unit. Depending on the type of branching and the spatial position of sympodial axes, six modifications of architectural unit were identified. It is established that the structure of mature individuals are formed due to the repetition one of the same modification of architectural unit or a combination different modifications of architectural unit. Each of the variants of the combination determines the type of life form (dwarf shrub or dwarf subshrub) and biomorph (monocentric, dense polycentric, sparse polycentric) and depends on the conditions of the ecotope. The identified modifications of the architectural unit and the variants of their combination determine the strategy for the development of dwarf shrubs and dwarf subshrubs in the development of Northern and Central Asia.


2006 ◽  
Vol 86 (5) ◽  
pp. 859-869 ◽  
Author(s):  
Francis Zvomuya ◽  
Francis J Larney ◽  
Olalekan O Akinremi ◽  
Reynald L Lemke ◽  
Vasile E Klaassen

Sustained plant nutrient a vailability on reclaimed wellsites is critical to the successful restoration of crop productivity. This study evaluated topsoil replacement depth (TRD) (0, 50, 100, and 150% of mandatory TRD) and organic amendment [beef cattle feedlot manure, compost derived from straw-bedded cattle feedlot manure, wheat (Triticum aestivumL.) straw, alfalfa (Medicago sativaL.) hay, and unamended control] effects on nutrient uptake by a wheat crop at three abandoned gas wellsites in south-central Alberta. Grain N uptake increased by 0.055 kg ha-1 for each percent increase in TRD, reflecting the corresponding linear increase in grain N concentration. Low carbon to nitrogen (C:N) ratio amendments, particularly compost and alfalfa, were the most effective for improving grain N concentration and uptake. Conversely, N concentration and uptake were lowest for the high C:N (53:1) wheat straw amendment. Reclamation programs should, therefore, consider incorporation of the low C:N alfalfa or compost in order to safeguard against N deficiency in the first 1–2 yr following reclamation. Our results also show that high P amendments, such as manure and compost, are better choices for improving P uptake by spring wheat. These results emphasize the importance of topsoil replacement and amendment quality (C:N ratio and P concentration) in ensuring adequate N and P supply in the 1–2 yr following reclamation. Based on this, compost appears to be the best single amendment for ensuring enhanced uptake of both N and P on reclaimed wellsites in the short term. Key words: Topsoil replacement; organic amendments; reclamation; nitrogen; phosphorus


Author(s):  
Oriana Sanicola ◽  
Terry Lucke ◽  
Michael Stewart ◽  
Katharina Tondera ◽  
Christopher Walker

Constructed Floating Wetlands (CFWs) are increasingly being used globally in freshwater environments such as urban lakes and ponds to remove pollutants from urban stormwater runoff. However, to date there has been limited research into the use and performance of these systems in saline environments. This study compared the root and shoot biomass growth and nutrient uptake of five different plant species, Chrysopogon zizanioides, Baumea juncea, Isolepis nodosa, Phragmites australis and Sarcocornia quinqueflora, in three different saltwater treatments over a 12-week period. The aim of the study was to identify which of the plant species may be most suitable for use in CFWs in saline environments. Plant nutrient uptake testing revealed that Phragmites australis had the greatest percentage increase (1473–2477%) of Nitrogen mass in the shoots in all treatments. Sarcocornia quinqueflora also had impressive Nitrogen mass increase in saltwater showing an increase of 966% (0.208 ± 0.134 g). This suggests that the use of Phragmites australis and Sarcocornia quinqueflora plants in CFWs installed in saline water bodies, with regular harvesting of the shoot mass, may significantly reduce Nitrogen concentrations in the water. Isolepis nodosa had the greatest percentage increase (112% or 0.018 ± 0.020 g) of Phosphorous mass in the shoots in the saltwater treatment. Baumea juncea had the greatest percentage increase (315% or 0.026 ± 0.012 g) of Phosphorous mass in the roots in the saltwater treatment. This suggests that the use of Isolepis nodosa and Baumea juncea plants in CFWs installed in saline water bodies may significantly reduce Phosphorous concentrations in the water if there was a way to harvest both the shoots above and the roots below the CFWs. The study is continuing, and it is anticipated that more information will be available on CFW plants installed in saline environments in the near future.


2016 ◽  
Vol 31 (2) ◽  
pp. 469-479 ◽  
Author(s):  
Wei‐Ping Zhang ◽  
Guang‐Cai Liu ◽  
Jian‐Hao Sun ◽  
Dario Fornara ◽  
Li‐Zhen Zhang ◽  
...  

2019 ◽  
Vol 15 ◽  
pp. 01007
Author(s):  
N. Delabays ◽  
A.F. Grogg ◽  
M. Mota ◽  
U. Piantini

The installation of a permanent ground cover in vineyards offers numerous agronomic (soil protection, soil fertility) and environmental (reduced leaching of nutrients and of plant protection products, reduced use of herbicides, biodiversity) benefits. Nevertheless, such ground covers are not always free of drawbacks (competition for water and nitrogen, increased risk of frost, management). For the growers, the challenge is to manage the green ground covers in such a way as to preserve their advantages while limiting these drawbacks. Among the tools available to the winegrower is the sowing of a seed mixture composed of selected species: a choice depending of the soil and climatic conditions of the parcel, but also of the different, and sometime contradictory, objectives of the grower. This paper lists the agronomic and environmental issues addressed by the installation of a permanent ground cover in vineyards. It describes two concrete situations – ground cover for vineyards integrated in agro-ecological networks and green cover on the row of vines (as alternative to glyphosate) – for which, according to the objectives and the impacts, a choice of plant species is proposed. At last, it presents the trials now carried out to validate and optimize those selections, as well as the first observations and results gathered to date.


2020 ◽  
Vol 1004 ◽  
pp. 349-354
Author(s):  
Takuma Narahara ◽  
Shin Ichiro Sato ◽  
Kazutoshi Kojima ◽  
Yuichi Yamazaki ◽  
Yasuto Hijikata ◽  
...  

Spin defects of which states can be manipulated in Silicon Carbide (SiC) have drawn considerable attention because of their applications to quantum technologies. The single negatively-charged pairs of VSi and nitrogen atom (N) on an adjacent C site (NCVSi- center) in SiC is suitable for them. This paper reports the formation of NCVSi- centers on 4H-SiC epilayers with different nitrogen concentrations using light/heavy ion irradiation and subsequent thermal annealing. The formation of NCVSi- centers is characterized by the near infrared photoluminescence (PL) spectroscopy. It is shown that the PL intensity from NCVSi- centers depends on the N concentration and the ion irradiation conditions. The PL intensity increases monotonically with increasing the N concentration when the N concentration is above 2.6×1016 cm-3, whereas no linear correlation between them does not appear below that N concentration. Although the PL intensity increases with increasing defects induced by ion irradiation, the PL quenching due to neighboring residual defects appear at above the areal vacancy concentration of 1017 vac/cm2 and the broad Raman scattering spectra originated from vibration modes of amorphized regions hinder the PL from NCVSi- centers at above 1018 vac/cm2. The formation mechanism and the charge state stability of NCVSi- centers are discussed based on the obtained results.


2014 ◽  
Vol 25 (4) ◽  
pp. 773-778 ◽  
Author(s):  
Shuai Yu ◽  
Wei Chen ◽  
Xingyuan He ◽  
Zhouli Liu ◽  
Yanqing Huang

2013 ◽  
Vol 33 (13) ◽  
pp. 4205-4213
Author(s):  
胡振宏 HU Zhenhong ◽  
何宗明 HE Zongming ◽  
范少辉 FAN Shaohui ◽  
黄志群 HUANG Zhiqun ◽  
万晓华 WAN Xiaohua ◽  
...  

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