Responses of Ecological Stoichiometric Characteristics of Carbon, Nitrogen, and Phosphorus to Periodic Submergence in Mega-Reservoir: Growth of Taxodium distichum and Taxodium ascendens

Ecological stoichiometric studies can be useful for managing the deteriorated riparian zones of mega-reservoirs in which nutrients significantly impact the balanced vegetation cover. The present study aims to explore the effects of periodic submergence on the stoichiometric ecological characteristics of carbon (C), nitrogen (N), and phosphorus (P), as well as the growth conditions of two leading conifer species (Taxodium distichum and Taxodium ascendens) in the hydro-fluctuation zone of the Three Gorges Reservoir (TGR) region, China. The stoichiometrical contents of C, N, and P in fine roots, leaves, and branches, and the growth conditions of T. distichum and T. ascendens were measured in July 2019. The results showed that periodic submergence affected the stoichiometric characteristics and growth conditions of these two woody species, and the impact was restrained, but both grew well. The effects of inundation on the C, N, and P ecological stoichiometric characteristics differed in different parts of trees. In general, the C contents showed the following pattern: leaves > branches > fine roots. The N and P content showed the following pattern: leaves > fine roots > branches, while the C/N and C/P ratios showed an opposite trend to that of N and P. The N and P content in all parts of T. distichum (with means of 17.18 and 1.70 g/kg for leaves, 4.80 and 0.57 g/kg for branches, and 6.88 and 1.10 g/kg for fine roots, respectively) and T. ascendens (with means of 14.56 and 1.87 g/kg for leaves, 5.03 and 0.63 g/kg for branches, and 8.17 and 1.66 g/kg for fine roots, respectively) were higher than the national average level (with means of 14.14 and 1.11 g/kg for leaves, 3.04 and 0.31 g/kg for branches, and 4.85 and 0.47 g/kg for fine roots, respectively). Except for N and P contents in the leaves of T. distichum, there was a significant correlation between N and P elements in other parts (p < 0.05). Nevertheless, the N/P ratio (10.15, 8.52, 6.44, and 7.93, 8.12, 5.20 in leaves, branches, and fine roots of T. distichum and T. ascendens, respectively) was lower than the critical ratio of 14. The growth conditions of T. distichum and T. ascendens were significantly negatively correlated with their leaf C contents and significantly positively correlated with their fine root N and P contents. This study showed that T. distichum and T. ascendens could maintain their normal growth needs by properly allocating nutrients between different organs to adapt to the long periodic submergence in the hydro-fluctuation zone of the TGR region.

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Carbon, nitrogen, and phosphorus ecological stoichiometric characteristics in leaves and fine roots of Taxodium distichum in the water-level fluctuation zone of the Three Gorges Reservoir region

Journal of Lake Sciences ◽

10.18307/2020.0620 ◽

2020 ◽

Vol 32 (6) ◽

pp. 1806-1816

Author(s):

LIU Minghui ◽

◽

XIE Tingting ◽

YUAN Zhongxun ◽

LI Lijuan ◽

...

Keyword(s):

Water Level ◽

Fine Roots ◽

Three Gorges Reservoir ◽

Taxodium Distichum ◽

Level Fluctuation ◽

Three Gorges ◽

Nitrogen And Phosphorus ◽

The Three Gorges Reservoir ◽

The Three Gorges ◽

Water Level Fluctuation Zone

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Heterotrophic Kinetic Parameter Estimation for Enhanced Biological Phosphorus Removal Processes Operated in Conventional and Membrane-Assisted Modes

Water Quality Research Journal ◽

10.2166/wqrj.2006.008 ◽

2006 ◽

Vol 41 (1) ◽

pp. 72-83 ◽

Cited By ~ 2

Author(s):

Zhe Zhang ◽

Eric R. Hall

Keyword(s):

Parameter Estimation ◽

Phosphorus Removal ◽

Growth Yield ◽

Pilot Scale ◽

Enhanced Biological Phosphorus Removal ◽

Biological Phosphorus Removal ◽

Nitrogen And Phosphorus ◽

Parameter Values ◽

The Impact ◽

Biological Phosphorus

Abstract Parameter estimation and wastewater characterization are crucial for modelling of the membrane enhanced biological phosphorus removal (MEBPR) process. Prior to determining the values of a subset of kinetic and stoichiometric parameters used in ASM No. 2 (ASM2), the carbon, nitrogen and phosphorus fractions of influent wastewater at the University of British Columbia (UBC) pilot plant were characterized. It was found that the UBC wastewater contained fractions of volatile acids (SA), readily fermentable biodegradable COD (SF) and slowly biodegradable COD (XS) that fell within the ASM2 default value ranges. The contents of soluble inert COD (SI) and particulate inert COD (XI) were somewhat higher than ASM2 default values. Mixed liquor samples from pilot-scale MEBPR and conventional enhanced biological phosphorus removal (CEBPR) processes operated under parallel conditions, were then analyzed experimentally to assess the impact of operation in a membrane-assisted mode on the growth yield (YH), decay coefficient (bH) and maximum specific growth rate of heterotrophic biomass (µH). The resulting values for YH, bH and µH were slightly lower for the MEBPR train than for the CEBPR train, but the differences were not statistically significant. It is suggested that MEBPR simulation using ASM2 could be accomplished satisfactorily using parameter values determined for a conventional biological phosphorus removal process, if MEBPR parameter values are not available.

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Fish farming in Denmark: environmental impact of regulative legislation

Water Science & Technology ◽

10.2166/wst.1995.0365 ◽

1995 ◽

Vol 31 (10) ◽

pp. 73-84 ◽

Cited By ~ 3

Author(s):

T. M. Iversen

Keyword(s):

Organic Matter ◽

Environmental Impact ◽

Freshwater Fish ◽

Aquatic Environment ◽

Action Plan ◽

Fish Farming ◽

Fish Farms ◽

Nitrogen And Phosphorus ◽

Local Impact ◽

The Impact

The main environmental problems associated with fish farming in Denmark are attributable to the dam, the “dead reach” and nutrient and organic matter discharge. The environmental regulation of fish farming in Denmark started with the Environmental Protection Act of 1974, the Statutory Order of 1985 forbidding wet feed, and the Action Plan on the Aquatic Environment of 1987. In the case of freshwater fish farms, the latter was implemented through the measures stipulated in the 1989 Statutory Order on Fish Farms. The impact of Danish legislative measures to reduce and regulate the environmental effects of freshwater fish farms can be summarized as follows: - the number of fish farms has been reduced from about 800 in 1974 to about 500 at present; - production has tripled since 1974 and has been stable since 1989; - a change from wet to dry feed has reduced the environmental impact of the farms; - the national goals of the Action Plan on the Aquatic Environment of 1987 for reducing fish farm discharges of organic matter, nitrogen and phosphorus have been fulfilled. The main remaining problems are that: - the local impact of fish farms on downstream stream quality is still much too high in about 15% of cases; - the problem of the passage of migrating invertebrates and fish is still unsolved at some farms; - the problems posed by “dead reaches” are still unsolved. It is concluded that sustainable fish farming is possible in Denmark, but with the present technology production will have to be significantly reduced.

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Organic mulching promotes soil organic carbon accumulation to deep soil layer in an urban plantation forest

Forest Ecosystems ◽

10.1186/s40663-020-00278-5 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Xiaodan Sun ◽

Gang Wang ◽

Qingxu Ma ◽

Jiahui Liao ◽

Dong Wang ◽

...

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Carbon Content ◽

Fine Roots ◽

Soil Layer ◽

Carbon Accumulation ◽

Bulk Soil ◽

Organic Mulch ◽

The Impact ◽

Soc Fractions

Abstract Background Soil organic carbon (SOC) is important for soil quality and fertility in forest ecosystems. Labile SOC fractions are sensitive to environmental changes, which reflect the impact of short-term internal and external management measures on the soil carbon pool. Organic mulching (OM) alters the soil environment and promotes plant growth. However, little is known about the responses of SOC fractions in rhizosphere or bulk soil to OM in urban forests and its correlation with carbon composition in plants. Methods A one-year field experiment with four treatments (OM at 0, 5, 10, and 20 cm thicknesses) was conducted in a 15-year-old Ligustrum lucidum plantation. Changes in the SOC fractions in the rhizosphere and bulk soil; the carbon content in the plant fine roots, leaves, and organic mulch; and several soil physicochemical properties were measured. The relationships between SOC fractions and the measured variables were analysed. Results The OM treatments had no significant effect on the SOC fractions, except for the dissolved organic carbon (DOC). OM promoted the movement of SOC to deeper soil because of the increased carbon content in fine roots of subsoil. There were significant correlations between DOC and microbial biomass carbon and SOC and easily oxidised organic carbon. The OM had a greater effect on organic carbon fractions in the bulk soil than in the rhizosphere. The thinnest (5 cm) mulching layers showed the most rapid carbon decomposition over time. The time after OM had the greatest effect on the SOC fractions, followed by soil layer. Conclusions The frequent addition of small amounts of organic mulch increased SOC accumulation in the present study. OM is a potential management model to enhance soil organic matter storage for maintaining urban forest productivity.

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Versatile Physiological Functions of Plant GSK3-Like Kinases

Genes ◽

10.3390/genes12050697 ◽

2021 ◽

Vol 12 (5) ◽

pp. 697

Author(s):

Juan Mao ◽

Wenxin Li ◽

Jing Liu ◽

Jianming Li

Keyword(s):

Stress Responses ◽

Glycogen Synthase ◽

Plant Stress ◽

Normal Growth ◽

Growth Conditions ◽

Genetic Studies ◽

Physiological Functions ◽

Environmental Signals ◽

Plant Stress Responses ◽

Diverse Plant

The plant glycogen synthase kinase 3 (GSK3)-like kinases are highly conserved protein serine/threonine kinases that are grouped into four subfamilies. Similar to their mammalian homologs, these kinases are constitutively active under normal growth conditions but become inactivated in response to diverse developmental and environmental signals. Since their initial discoveries in the early 1990s, many biochemical and genetic studies were performed to investigate their physiological functions in various plant species. These studies have demonstrated that the plant GSK3-like kinases are multifunctional kinases involved not only in a wide variety of plant growth and developmental processes but also in diverse plant stress responses. Here we summarize our current understanding of the versatile physiological functions of the plant GSK3-like kinases along with their confirmed and potential substrates.

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Global scaling the leaf nitrogen and phosphorus resorption of woody species: revisiting some commonly held views

The Science of The Total Environment ◽

10.1016/j.scitotenv.2021.147807 ◽

2021 ◽

pp. 147807

Author(s):

Miaoping Xu ◽

Yufan Zhu ◽

Shuohong Zhang ◽

Yongzhong Feng ◽

Wei Zhang ◽

...

Keyword(s):

Woody Species ◽

Leaf Nitrogen ◽

Nitrogen And Phosphorus ◽

Global Scaling ◽

Leaf Nitrogen And Phosphorus

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Beavers, Bugs and Chemistry: A Mammalian Herbivore Changes Chemistry Composition and Arthropod Communities in Foundation Tree Species

Forests ◽

10.3390/f12070877 ◽

2021 ◽

Vol 12 (7) ◽

pp. 877

Author(s):

Rachel M. Durben ◽

Faith M. Walker ◽

Liza Holeski ◽

Arthur R. Keith ◽

Zsuzsi Kovacs ◽

...

Keyword(s):

Tree Species ◽

Castor Canadensis ◽

Habitat Type ◽

Food Preferences ◽

Woody Species ◽

Juvenile Growth ◽

Arthropod Community ◽

Riparian Ecosystems ◽

Arthropod Communities ◽

The Impact

The North American beaver (Castor canadensis Kuhl) and cottonwoods (Populus spp.) are foundation species, the interactions of which define a much larger community and affect a threatened riparian habitat type. Few studies have tested the effect of these interactions on plant chemistry and a diverse arthropod community. We experimentally examined the impact of beaver foraging on riparian communities by first investigating beaver food preferences for one cottonwood species, Fremont cottonwood (P. fremontii S. Watson), compared to other locally available woody species. We next examined the impact of beaver foraging on twig chemistry and arthropod communities in paired samples of felled and unfelled cottonwood species in northern Arizona (P. fremontii) and southwestern Colorado (narrowleaf cottonwood, P. angustifolia James, and Eastern cottonwood, P. deltoides W. Bartram ex Marshall). Four major patterns emerged: (1) In a cafeteria experiment, beavers chose P. fremontii six times more often than other woody native and exotic species. (2) With two cottonwood species, we found that the nitrogen and salicortin concentrations were up to 45% greater and lignin concentration 14% lower in the juvenile resprout growth of felled trees than the juvenile growth on unfelled trees (six of seven analyses were significant for P. fremontii and four of six were significant for P. angustifolia). (3) With two cottonwood species, arthropod community composition on juvenile branches differed significantly between felled and unfelled trees, with up to 38% greater species richness, 114% greater relative abundance and 1282% greater species diversity on felled trees (six of seven analyses with P. fremontii and four of six analyses with P. angustifolia were significant). The above findings indicate that the highest arthropod diversity is achieved in the heterogenous stands of mixed felled and unfelled trees than in stands of cottonwoods, where beavers are not present. These results also indicate that beaver herbivory changes the chemical composition in 10 out of 13 chemical traits in the juvenile growth of two of the three cottonwood species to potentially allow better defense against future beaver herbivory. (4) With P. deltoides, only one of five analyses in chemistry was significant, and none of the four arthropod community analyses were significant, suggesting that this species and its arthropod community responds differently to beaver. Potential reasons for these differences are unknown. Overall, our findings suggest that in addition to their impact on riparian vegetation, other mammals, birds, and aquatic organisms, beavers also may define the arthropod communities of two of three foundation tree species in these riparian ecosystems.

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Diversification of Dawkinsia filamentosa (Valenciennes, 1844) and their growth conditions by the impact of toxic metals in the river Tamiraparani

Ecotoxicology ◽

10.1007/s10646-021-02427-0 ◽

2021 ◽

Author(s):

Sabaridasan Arumugam ◽

Mohamed Shahila Abul Asan Sathali ◽

Soranam Ramaiah ◽

Gandhimaniyan Krishnan

Keyword(s):

Toxic Metals ◽

Growth Conditions ◽

The Impact

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Sequence and regulation of a gene encoding a human 89-kilodalton heat shock protein.

Molecular and Cellular Biology ◽

10.1128/mcb.9.6.2615 ◽

1989 ◽

Vol 9 (6) ◽

pp. 2615-2626 ◽

Cited By ~ 172

Author(s):

E Hickey ◽

S E Brandon ◽

G Smale ◽

D Lloyd ◽

L A Weber

Keyword(s):

Heat Shock ◽

Heat Shock Protein ◽

Normal Growth ◽

Gene Families ◽

Growth Conditions ◽

Complete Sequence ◽

Start Codon ◽

Hybridization Probe ◽

Reading Frame ◽

Alpha Gene

Vertebrate cells synthesize two forms of the 82- to 90-kilodalton heat shock protein that are encoded by distinct gene families. In HeLa cells, both proteins (hsp89 alpha and hsp89 beta) are abundant under normal growth conditions and are synthesized at increased rates in response to heat stress. Only the larger form, hsp89 alpha, is induced by the adenovirus E1A gene product (M. C. Simon, K. Kitchener, H. T. Kao, E. Hickey, L. Weber, R. Voellmy, N. Heintz, and J. R. Nevins, Mol. Cell. Biol. 7:2884-2890, 1987). We have isolated a human hsp89 alpha gene that shows complete sequence identity with heat- and E1A-inducible cDNA used as a hybridization probe. The 5'-flanking region contained overlapping and inverted consensus heat shock control elements that can confer heat-inducible expression on a beta-globin reporter gene. The gene contained 10 intervening sequences. The first intron was located adjacent to the translation start codon, an arrangement also found in the Drosophila hsp82 gene. The spliced mRNA sequence contained a single open reading frame encoding an 84,564-dalton polypeptide showing high homology with the hsp82 to hsp90 proteins of other organisms. The deduced hsp89 alpha protein sequence differed from the human hsp89 beta sequence reported elsewhere (N. F. Rebbe, J. Ware, R. M. Bertina, P. Modrich, and D. W. Stafford (Gene 53:235-245, 1987) in at least 99 out of the 732 amino acids. Transcription of the hsp89 alpha gene was induced by serum during normal cell growth, but expression did not appear to be restricted to a particular stage of the cell cycle. hsp89 alpha mRNA was considerably more stable than the mRNA encoding hsp70, which can account for the higher constitutive rate of hsp89 synthesis in unstressed cells.

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