scholarly journals Effects of Drying and Re-Wetting on Litter Decomposition and Nutrient Recycling: A Manipulative Experiment

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 708 ◽  
Author(s):  
Beatrice Palmia ◽  
Marco Bartoli ◽  
Alex Laini ◽  
Rossano Bolpagni ◽  
Claudio Ferrari ◽  
...  
Keyword(s):  
Interactive Effect ◽  
Nutrient Recycling ◽  
Leaf Size ◽  
Leaf Biomass ◽  
Manipulative Experiment ◽  
Water Abstraction ◽  
Nutrient Mineralization ◽  
Stream Drying ◽  
Benthic Environment ◽  
Leaf Disks

Climate change and water abstraction may change stream flow from perennial into intermittent lotic systems, modifying their abiotic and biotic benthic environment and impacting ecosystem processes such as nutrient turnover. We conducted a microcosm experiment to investigate the interactive effect of water intermittency, macrofauna and leaf size (Populus nigra leaves) on nutrient mineralization and recycling. Leaf disks (1 or 5 cm diameter) were incubated for 40 days with or without the leaf-consumer, Potamophylax cingulatus larvae (Trichoptera, Limnephilidae) and with or without an intervening, 10-days simulation of stream drying and subsequent rewetting. Nutrient fluxes, residual leaf biomass and leaf elemental composition were measured to evaluate how intermittency, macrofauna and leaf size affect organic matter mineralization rates and stoichiometry. Results suggest that drying slows decomposition rates, impacting both the microbial and setting to zero macrofauna activities. The presence of macrofauna increases mineralization and nutrient (C, N and P) regeneration rates. Our findings also suggest that leaf disks with higher diameter display higher microbial activity and NH4+ regeneration. During the experiment, the C:N:P ratios of residual litter changed, as the leaf material became enriched with N and P. Our study suggests that increasingly frequent dry events might slow mineralization rates and downstream nutrient transport.

scholarly journals Trophic Trait Evolution Explains Variation in Nutrient Excretion Stoichiometry among Panamanian Armored Catfishes (Loricariidae)

Diversity ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 88
Author(s):  
Eric K. Moody ◽  
Fernando Alda ◽  
Krista A. Capps ◽  
Oscar Puebla ◽  
Benjamin L. Turner
Keyword(s):  
Significant Variation ◽  
Trophic Position ◽  
Nutrient Recycling ◽  
Trophic Niche ◽  
Relative Importance ◽  
Closely Related Species ◽  
Trait Evolution ◽  
Nutrient Excretion ◽  
Nutrient Mineralization ◽  
Excretion Rates

Variation in nutrient excretion rates and stoichiometric ratios (e.g., nitrogen to phosphorus) by consumers can have substantial effects on aquatic ecosystem function. While phylogenetic signals within an assemblage often explain variation in nutrient recycling rates and stoichiometry, the phylogenetically conserved traits that underlie this phenomenon remain unclear. In particular, variation in nutrient excretion stoichiometry across a phylogeny might be driven by phylogenetic patterns in either diet or body stoichiometry. We examined the relative importance of these traits in explaining variation in nutrient recycling rates and stoichiometry in a diverse family of Neotropical-armored catfishes, Loricariidae, in Panamanian streams. We found significant variation in nutrient mineralization traits among species and subfamilies, but variation in nutrient excretion stoichiometry among species was best explained by trophic position rather than body stoichiometry. The variation in trophic position among Panamanian species was consistent with variation in the trophic niche of their genera across South America, suggesting that phylogenetic patterns underpin the evolution of trophic and nutrient excretion traits among these species. Such geographical variation in nutrient mineralization patterns among closely related species may be common, given that trophic variation in fish lineages occurs widely. These results suggest that information on trophic trait evolution within lineages will advance our understanding of the functional contribution of animals to biogeochemical cycling.

scholarly journals Interactive Effect of Elevated CO2 and Moisture Stress on Anatomical Configuration in Brassica Species

2021 ◽  
pp. 142-156
Author(s):  
Ranjan Das
Keyword(s):  
Elevated Co2 ◽  
Interactive Effect ◽  
Co2 Enrichment ◽  
Leaf Size ◽  
Brassica Species ◽  
Moisture Stress ◽  
Structural Development ◽  
Free Air ◽  
Brassica Plant ◽  
Study Results

Free-Air CO2 Enrichment (FACE) was developed as a means to study the crops response to elevated level of CO2 under the fully open-air field conditions. In this study, results of FACE experiments are summarized by disusing the root and shoot anatomy. Result indicated that elevated Co2 significantly altered the root and shoot xylem and phloem characters such as both proto and meta xylem and phloem; vessels, character of root and shoots which are vital for the transpiration regulation, along with leaves photosynthesis as a whole. The coexistence of two ontogenetically different phloem sieve element in Brassica plant under elevated CO2 might have possibility of two different transport functions at the same time. One may be involved in supplying for the structural development (leaf size, stem girth and root volume) and other may cater the need of increased new sinks. Though these parameters were found to decrease under moisture stress condition but these impacts of stress were reduced at higher level of atmospheric CO2.

scholarly journals THE EFFECT OF COVER CROP AND SOIL SOLARIZATION ON TURNIP GREEN YIELD AND NUTRIENT MINERALIZATION

HortScience ◽  
1990 ◽  
Vol 25 (8) ◽  
pp. 861c-861
Author(s):  
D. R. Earhart ◽  
V. A. Haby ◽  
A. T. Leonard ◽  
J. V. Davis
Keyword(s):  
Soil Salinity ◽  
Cover Crop ◽  
Soil Analysis ◽  
Interactive Effect ◽  
Linear Increase ◽  
Interactive Effects ◽  
Soil Solarization ◽  
N Application ◽  
Nutrient Mineralization ◽  
Application Rates

Soil solarization following previous N application rates of 0, 56, 112, 168 and 224 kg·ha-1 as ammonium nitrate, and one cover crop of-sorghum-sudah (Sorghum bicolor var.) increased yields of turnip foliage (greens) by 3066 kg·ha-1 over the non-solarized treatment. Greater yield was obtained with 56 kg·ha-1 less N with solarization than non-solarization (112 vs 168 kg·ha-1). A blanket N application of 22 kg·ha-1 ameliorated the solarization effect on the 2nd harvest. Solarization had no significant effect on turnip leaf element concentration. Linear and quadratic increases in leaf N occurred as soil N increased. There was also a linear increase in tissue K and Mg due to solarization. No interactive effects were noted. Soil analysis showed salinity (EC) decreased and Ca increased with solarization. An increase in N rates decreased pH, NO3, and Mg, and increased soil salinity and NH4. Solarization had an interactive effect on soil salinity by increasing EC at 0 N and decreasing at 56 to 168 kg N·ha-1.

scholarly journals Substrate Water Content and Fertilizer Rate Affect Growth and Flowering of Potted Petunia

HortScience ◽  
2015 ◽  
Vol 50 (4) ◽  
pp. 582-589 ◽  
Author(s):  
Peter Alem ◽  
Paul A. Thomas ◽  
Marc W. van Iersel
Keyword(s):  
Water Content ◽  
Interactive Effect ◽  
Leaf Size ◽  
Dry Weight ◽  
Optimal Conditions ◽  
Fertilizer Rate ◽  
Shoot Dry Weight ◽  
Four Levels ◽  
Fertilizer Rates ◽  
Excessive Water

Rising concerns over environmental impacts of excessive water and fertilizer use in the horticultural industry necessitate more efficient use of water and nutrients. Both substrate volumetric water content (θ) and fertilizer affect plant growth, but their interactive effect is poorly understood. The objective of this study was to determine the optimal fertilizer rates for petunia (Petunia ×hybrida) ‘Dreams White’ grown at different θ levels. Petunia seedlings were grown at four levels of θ (0.10, 0.20, 0.30, and 0.40 m3·m−3) with eight different rates of controlled-release fertilizer (CRF) (Osmocote 14-14-14; 14N–6.1P–11.6K; rates of 0 to 2.5 g/plant, equivalent to 0 to 6.25 kg·m−3 substrate). Shoot dry weight increased as the CRF rate increased from 0 to 1.67 g/plant but decreased again at even higher CRF rates. The effect of CRF rate on growth was more pronounced at higher θ. Leaf size doubled as the θ thresholds increased from 0.10 to 0.40 m3·m−3. Flowering was reduced by a combination of high CRF rates (greater than 0.63 g/plant) and high θ (0.30 and 0.40 m3·m−3), indicating that optimal conditions for vegetative growth are different from those for maximal flowering. These results suggest that without leaching, high-quality petunias can be grown with lower CRF rates than commercially recommended rates.

scholarly journals Effects of artificial defoliation on growth, reproduction and leaf chemistry of the mangrove Kandelia candel

2003 ◽  
Vol 19 (4) ◽  
pp. 397-406 ◽  
Author(s):  
Y. F. Tong ◽  
S. Y. Lee ◽  
B. Morton
Keyword(s):  
Hong Kong ◽  
Community Structure ◽  
Adverse Effects ◽  
Total Nitrogen ◽  
Leaf Biomass ◽  
Kandelia Candel ◽  
Leaf Chemistry ◽  
Leaf Lamina ◽  
Negative Effects ◽  
Manipulative Experiment

The effects of defoliation on leaf and propagule production, and leaf chemistry of the mangrove Kandelia candel (L.) Druce were evaluated in a manipulative experiment in Hong Kong. Artificial defoliation of leaf lamina at 50% of the length of midrib resulted in significant reduction in leaf, twig and propagule production, and size of the latter. Through the negative effects on propagule number and size, severe herbivory may influence fitness of the mangrove, and, thus, community structure. In contrast, no apparent adverse effects on growth and production were observable at 25% defoliation. Defoliation also significantly affected leaf chemistry of the trees, particularly those suffering 50% defoliation. Concentrations of soluble tannins and carbohydrates in leaves were significantly lower at 50% defoliation compared with the control. Total nitrogen also decreased significantly with increased per cent defoliation. Plants surviving in stressful habitats, such as mangroves, are probably more affected by loss of leaf biomass than those surviving in favourable environments.

scholarly journals Consumer-driven nutrient recycling of freshwater decapods: linking ecological theories and application in integrated multi-trophic aquaculture

2022 ◽  
Author(s):  
Gabriela Musin ◽  
María Victoria Torres ◽  
Débora de Azevedo Carvalho
Keyword(s):  
Body Mass ◽  
Nutrient Recycling ◽  
Elemental Content ◽  
Fish Feed ◽  
Nutrient Inputs ◽  
Nutrient Excretion ◽  
Nutrient Mineralization ◽  
Physiological Variables ◽  
Excretion Rates ◽  
Productive Systems

The Metabolic Theory of Ecology (MET) and the Ecological Stoichiometry Theory (EST) are central and complementary in the consumer-driven recycling conceptual basis. The comprehension of physiological processes of organisms at different levels of organizations is essential to explore and predict nutrient recycling behavior in different scenarios, and to design integrated productive systems that efficiently use the nutrient inputs through an adjusted mass balance. We fed with fish-feed three species of decapods from different families and with aquacultural potential to explore the animal-mediated nutrient dynamic and its applicability in productive systems. We tested whether physiological (body mass, body elemental content), ecological (diet), taxonomic and experimental (time of incubation) variables predicts N and P excretion rates and ratios across and within taxa. We also analysed body mass and body elemental content independently as predictors of N and P excretion of decapods across, among and within taxa. Finally, we verified if body content scales allometrically across and within taxa and if differed among taxa. Body mass and taxonomic identity predicted nutrient excretion rates both across and within taxa. When physiological variables were analysed independently, body size best predicted nutrient mineralization in both scales of analyses. Regarding body elemental content, only body P content scaled negatively with body mass across taxa. Results showed higher N-requirements and lower C:N of prawns than anomurans and crabs. The role of crustaceans as nutrient recyclers depends mainly on the species and body mass, and should be considered to select complementary species that efficiently use feed resources. Prawns need more protein in their feed and might be integrated with fish of higher N-requirements, while crabs and anomurans, with fish of lower N-requirements. Our study contributed to the background of MTE and EST through empirical data obtained from decapods and provided useful information to achieve more efficient aquaculture integration systems.

Effects of simulated green turtle regrazing on seagrass abundance, growth and nutritional status in Moreton Bay, south-east Queensland, Australia

2007 ◽  
Vol 58 (5) ◽  
pp. 492 ◽  
Author(s):  
Marianne Kuiper-Linley ◽  
Craig R. Johnson ◽  
Janet M. Lanyon
Keyword(s):  
Starch Content ◽  
Leaf Size ◽  
Water Soluble ◽  
Leaf Biomass ◽  
Soluble Carbohydrate ◽  
Seagrass Species ◽  
Green Turtles ◽  
Moreton Bay ◽  
Halophila Ovalis ◽  
Seagrass Biomass

In some parts of their range, green turtles maintain grazing plots in seagrass beds by regular regrazing. The effects of simulated repeated grazing on subtropical seagrasses in Moreton Bay, Australia were investigated in a manipulative experiment over summer. Three seagrass species were subjected to two different clipping frequencies (simulating turtle cropping) and compared with unclipped controls over a 3.5-month summer period for the effects on seagrass biomass, leaf size and regrowth rates and water-soluble carbohydrate (WSC) and starch content. The order of the seagrass species’ relative tolerance to simulated grazing was Halophila ovalis > Zostera capricorni > Cymodocea serrulata. Frequent regrazing of the green turtle’s preferred seagrass, H. ovalis, resulted in an increase in leaf regrowth rate so that standing biomass of leaves and total plant material was maintained, suggesting an increase in productivity. Furthermore, whole-plant concentrations of WSC increased significantly in clipped H. ovalis plants relative to unclipped controls. In contrast, leaf biomass of the seagrass species less preferred by turtles, Z. capricorni and C. serrulata, decreased in response to repeated leaf removal relative to controls, despite maintenance of leaf regrowth rates. C. serrulata responded to repeated clipping with a reduction in leaf size and a decrease in rhizome WSC concentration. Z. capricorni also produced fewer and smaller new leaves. The ability of the preferred species, H. ovalis, to increase production of nutrient-rich standing crop in response to regrazing has major implications for green turtles and other seagrass grazers.

scholarly journals The interactive effect of herbivory, nutrient enrichment and mucilage on shallow rocky macroalgal communities

2018 ◽  
Author(s):  
Sarah Caronni ◽  
Chiara Calabretti ◽  
Giulia Ceccherelli ◽  
Sandra Citterio ◽  
Maria Anna Delaria ◽  
...  
Keyword(s):  
Marine Protected Area ◽  
Interactive Effect ◽  
Term Effect ◽  
Short Term ◽  
Manipulative Experiment ◽  
Rocky Substratum ◽  
Long Term Effect ◽  
Short And Long Term ◽  
Macroalgal Assemblage

In this paper the results of a manipulative experiment aimed to evaluate the interactive short- and long-term effect of three different stressors, herbivory, nutrient and mucilage, on a macroalgal assemblage are presented. The experiment was conducted in Tavolara Punta Coda Cavallo Marine Protected Area during a bloom of the benthic mucilage-producing microalga Chrysophaeum taylorii Lewis and Bryan (Pelagophyceae), recently spreading in the Mediterranean Sea. On a rocky substratum, 18 plots 20x20 cm in size were prepared and, according to different treatments, nutrients were added in some of them to simulate eutrophication, macroalgae were removed to simulate clearings produced by grazers and mucilage was manually removed to simulate mucilage-free conditions. Differences in the composition of macroalgal assemblages were found when considering the short term effect of the considered stressors, and also the response of the most abundant taxa (DFA, ECA, Dictyotales, Laurencia spp. and Padina pavonica) varied among treatments, proving that a combined effect of such stressors on the recovery of macroalgae was present. On the contrary, the effect of treatments was neither highlighted on the most abundant algae nor on the whole structure of the macroalgal assemblage.

scholarly journals The interactive effect of herbivory, nutrient enrichment and mucilage on shallow rocky macroalgal communities

2018 ◽  
Author(s):  
Sarah Caronni ◽  
Chiara Calabretti ◽  
Giulia Ceccherelli ◽  
Sandra Citterio ◽  
Maria Anna Delaria ◽  
...  
Keyword(s):  
Marine Protected Area ◽  
Interactive Effect ◽  
Term Effect ◽  
Short Term ◽  
Manipulative Experiment ◽  
Rocky Substratum ◽  
Long Term Effect ◽  
Short And Long Term ◽  
Macroalgal Assemblage

In this paper the results of a manipulative experiment aimed to evaluate the interactive short- and long-term effect of three different stressors, herbivory, nutrient and mucilage, on a macroalgal assemblage are presented. The experiment was conducted in Tavolara Punta Coda Cavallo Marine Protected Area during a bloom of the benthic mucilage-producing microalga Chrysophaeum taylorii Lewis and Bryan (Pelagophyceae), recently spreading in the Mediterranean Sea. On a rocky substratum, 18 plots 20x20 cm in size were prepared and, according to different treatments, nutrients were added in some of them to simulate eutrophication, macroalgae were removed to simulate clearings produced by grazers and mucilage was manually removed to simulate mucilage-free conditions. Differences in the composition of macroalgal assemblages were found when considering the short term effect of the considered stressors, and also the response of the most abundant taxa (DFA, ECA, Dictyotales, Laurencia spp. and Padina pavonica) varied among treatments, proving that a combined effect of such stressors on the recovery of macroalgae was present. On the contrary, the effect of treatments was neither highlighted on the most abundant algae nor on the whole structure of the macroalgal assemblage.

scholarly journals Pertumbuhan dan Produktivitas Daun Lamun Thalassia hemprichii (Ehrenb) Ascherson di Perairan Tanjung Benoa, Bali

2017 ◽  
Vol 4 (2) ◽  
pp. 278
Author(s):  
Budi Santoso ◽  
I Gusti Bagus Sila Dharma ◽  
Elok Faiqoh
Keyword(s):  
Growth Rate ◽  
Leaf Age ◽  
Leaf Tissue ◽  
Leaf Size ◽  
Dry Weight ◽  
Nutrient Content ◽  
Leaf Biomass ◽  
Thalassia Hemprichii ◽  
Average Growth ◽  
Young Leaves

Thalassia hemprichii is one of the seagrass as favorite food of two protected herbivores such as Green Turtle and Dugong. The existence of Thalassia hemprichii and knowing the growth rate becomes very important for sustainability of two herbivores. The study was conducted in Tanjung Benoa waters that covering three parts of the coast such as Samuh, Conrad and Tanjung beach in February until March 2017. Thalassia hemprichii leaves growth is observed consist of long and heavy growth (dry weight) and measured leaf age that has been observed such as young, half old and old leaves. The method that used to measure the growth of Thalassia hemprichii is pruning method and determination the research location using purposive sampling method. The aim of this research is explained the growth rate, biomass, and productivity of young leaves, old leaves of Thalassia hemprichii in Tanjung Benoa Bali. Measurement results of Thalassia hemprichii growth between age group of leaves has different young leaves faster growth if compared with the half old leaves and old leaves with average growth is 3.41mm/day indicates that the efficiency of this seagrass growth will decrease as the leaves age. The highest biomass values ??were found in older leaves if compared with young leaves and half-old leaves with average 0.205 gbk/m2 expected because the thick and wide leaf size will produced larger leaf biomass. The highest productivity value is found in oldest leaves in each station with average 0.028 gbk/m2/day expected morphology and different nutrient content in each leaf tissue.

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