Two arctic tundra graminoids differ in tolerance to herbivory when grown with added soil nutrients

Botany ◽  
2013 ◽  
Vol 91 (2) ◽  
pp. 82-90 ◽  
Author(s):  
David R. Johnson ◽  
Laura Gough
Keyword(s):  
Soil Nutrients ◽  
Growth Form ◽  
Soil Nutrient ◽  
Functional Characteristic ◽  
Phosphorus Fertilization ◽  
Eriophorum Vaginatum ◽  
Nitrogen And Phosphorus ◽  
Herbivore Damage ◽  
Soil Nutrient Availability ◽  
Closed Canopy

Greater soil nutrients are thought to increase graminoid tolerance to herbivory (within-season regrowth following herbivore damage) by enabling new growth in response to defoliation, but these responses vary among graminoid species. We studied how two arctic graminoids, Eriophorum vaginatum (L.) in moist acidic tussock (MAT) tundra and Hierochloe alpina (Roem. & Schult.) in dry heath (DH) tundra, tolerate both experimental and natural herbivory when fertilized with nitrogen and phosphorus. Fertilization reduced the tolerance and recovery (regrowth in subsequent years) of defoliated Eriophorum relative to plants growing without fertilization. In contrast, fertilized Hierochloe plants regrew well following defoliation. These opposing results may be due to differential abilities of these two species to access other resources in MAT and DH when fertilized. Herbivory may be affecting access to light of Eriophorum in the more productive, closed canopy MAT, in spite of its ability to grow bigger when fertilized. Hierochloe may not face such a limitation in the more open DH community. Alternatively, the different responses between these two species could be caused by environmental differences between the two communities. Regardless, our results suggest that although high tolerance is thought to be a functional characteristic of graminoids, tolerance to herbivory varies within and between species with soil nutrient availability and thus caution must be exercised in predicting responses to herbivory within this plant growth form.

The effect of riparian restoration on channel complexity and soil nutrients

2017 ◽  
Vol 68 (11) ◽  
pp. 2041 ◽  
Author(s):  
J. Patrick Laceby ◽  
Nina E. Saxton ◽  
Kate Smolders ◽  
Justine Kemp ◽  
Stephen J. Faggotter ◽  
...  
Keyword(s):  
Soil Nutrients ◽  
Riparian Vegetation ◽  
Soil Nutrient ◽  
Nutrient Retention ◽  
River Channel ◽  
Channel Width ◽  
Riparian Restoration ◽  
Nitrogen And Phosphorus ◽  
Elemental Geochemistry ◽  
Channel Complexity

Restoration of riparian vegetation may reduce nutrient and sediment contamination of waterways while potentially enhancing stream channel complexity. Accordingly, the present study used a paired-site approach to investigate the effects of mature regrowth riparian vegetation on river channel morphology and soil nutrients (i.e. nitrogen and phosphorus), comparing four sites of degraded (pasture) and reforested reaches. A revised rapid assessment of riparian condition (RARC) was used to validate the site pairings. Riparian soil nutrient and elemental geochemistry were compared between paired sites, along with two parameters of channel width complexity and two for channel slope complexity. The RARC analysis confirmed the validity of the paired site design. The elemental geochemistry results indicated that underlying geology may affect the paired site analyses. Reaches with mature regrowth vegetation had greater channel width complexity but no difference in their riverbed slope complexity. In addition, degraded reaches had higher soil nutrient (i.e. nitrogen and phosphorus) concentrations, potentially indicative of the greater nutrient retention of pasture grass sites compared with mature regrowth forested reaches with less ground cover. Overall, the present study indicates that restoring mature regrowth riparian vegetation may increase river channel width complexity, although it may require canopy management to optimise the nutrient retention potential necessary to maximise the effect of riparian restoration strategies on freshwater environments.

Nutrient fluxes in litterfall and decomposition in four forests along a gradient of soil fertility in southern Ohio

1984 ◽  
Vol 14 (6) ◽  
pp. 794-802 ◽  
Author(s):  
Ralph E. J. Boerner
Keyword(s):  
Soil Fertility ◽  
Nutrient Availability ◽  
Soil Nutrient ◽  
Nutrient Concentrations ◽  
Strongly Correlated ◽  
Nitrogen And Phosphorus ◽  
Soil Nutrient Availability ◽  
Nutrient Mineralization ◽  
Nutrient Levels ◽  
Fertility Gradient

To determine how soil nutrient availability influences nutrient cycling, fluxes of nutrients through litterfall and decomposition were determined for four forest stands similar in all respects except soil nutrient availability and microclimate, within Neotoma Valley, a small watershed in southern Ohio, U.S.A. Litterfall varied from 10 to 60% among sites while nutrient concentrations and masses in new leaf litter varied as a function of extractable soil nutrient levels. Mass loss from litterbags was significantly higher in more fertile sites. Stepwise regression indicated that initial litter nitrogen and phosphorus concentrations were strongly correlated with relative decomposition rate while lignin concentration and microclimate variables were only correlated weakly. Thus, both litterfall nutrient transfers and decomposition rates were under the control of soil nutrient levels. Nitrogen was immobilized in litter at all sites during the 1st year of decay; litter from more fertile sites mineralized nitrogen during the 2nd year, while that from less fertile sites continued to immobilize nitrogen. Phosphorus and calcium mineralization rates were strongly correlated with the availability of these elements in the soil. Magnesium and potassium were leached rapidly from litter; amounts mineralized were correlated with amounts in litterfall. Interrelations among soil fertility, litterfall, and nutrient mineralization, as well as litter redistribution, are discussed as processes important in the development and maintenance of the soil fertility gradient in this watershed.

scholarly journals Females and hermaphrodites of the gynodioecious Geranium maculatum respond similarly to soil nutrient availability

2020 ◽  
Author(s):  
Katharine Putney ◽  
Mavis Wolf ◽  
Chase Mason ◽  
Shu-Mei Chang
Keyword(s):  
Nutrient Availability ◽  
Natural Populations ◽  
Soil Nutrient ◽  
Nitrogen And Phosphorus ◽  
Soil Nutrient Availability ◽  
Leaf Quality ◽  
Nitrogen Levels ◽  
Growth Allocation ◽  
Leaf Chlorophyll ◽  
Growth And Allocation

AbstractSexual dimorphism in plant growth and/or reproductive responses to the surrounding environment has been documented in some plant species. In gynodioecious plants, it is especially important to understand whether females and hermaphrodites differ in their response to environmental stressors, as the fitness of females relative to hermaphrodites determines the extent to which these separate sexes are maintained in natural populations. Soil nutrient availability is of particular importance given the different nutrient requirements of male and female sexual functions in plants. Here, we evaluated and compared the growth of females and hermaphrodites of Geranium maculatum in response to varying levels of nutrients. Using a greenhouse experiment, we manipulated the overall nutrient, nitrogen, and phosphorus levels in the soil and measured growth, allocation, and leaf quality responses in both females and hermaphrodites. We found that sexes responded similarly in their growth and allocation responses to nutrient availability, albeit evidence that female leaf chlorophyll content may have increased more than that of hermaphrodites across soil nitrogen levels. Our findings demonstrate that hermaphrodites differ from females in terms of their physiological response to varying nutrient levels, however these physiological differences did not translate into meaningful growth or reproduction differences.

scholarly journals Soil nutrient evolution under different vegetation types in semiarid loess area

2021 ◽  
pp. 969-976
Author(s):  
Lirong He ◽  
Yuhu Luo
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Nutrients ◽  
Total Nitrogen ◽  
Organic Fertilizer ◽  
Nutrient Balance ◽  
Soil Nutrient ◽  
Available Phosphorus ◽  
Vegetation Types ◽  
Nitrogen And Phosphorus

The soil nutrient characteristics under three vegetation types of arbor ( I ), shrub ( II ) and herb ( III ) were studied by mathematical statistics method combined with field investigation and indoor detection analysis. The change characteristics of soil nutrients under different land use patterns were discussed. The results showed that the average contents of soil organic matter, total nitrogen, available phosphorus and available potassium were 21.30 and 0.65 g/kg, 3.67 and 67.61 mg/kg, respectively. Compared with grassland, woodland has better effect on fertilizer conservation in the Loess Plateau. In the process of soil nutrient improvement, the nutrient indexes such as organic matter, total nitrogen, available phosphorus and available potassium increased synchronously, and the soil alkaline environment that was not conducive to plant growth was also gradually improved. In the correlation between soil nutrients, available phosphorus and available potassium have good relative independence. In the future, organic fertilizer should be applied in this area, and nitrogen and phosphorus fertilizers should be supplemented to improve soil organic matter, nitrogen and phosphorus content, and to ensure soil nutrient balance by optimizing fertilization methods. In addition, in the case of uneven distribution of soil nutrients in the soil profile, it is recommended to take appropriate soil ploughing and reasonable human management measures to improve soil nutrient status, achieve high-quality sustainable development of soil, and promote the positive succession of vegetation communities. Bangladesh J. Bot. 50(3): 969-976, 2021 (September) Special

Genotypic diversity and genotype identity of resident species drive community composition

2020 ◽  
Vol 13 (2) ◽  
pp. 224-232
Author(s):  
Věroslava Hadincová ◽  
Hana Skálová ◽  
Zuzana Münzbergová
Keyword(s):  
Genetic Diversity ◽  
Soil Nutrients ◽  
Plant Communities ◽  
Growth Form ◽  
Plantago Lanceolata ◽  
Soil Nutrient ◽  
Genotypic Diversity ◽  
Resident Species ◽  
Tussock Grass ◽  
Colonization Success

Abstract Aims Species-rich plant communities are more resistant to invasions. In the past decade it was demonstrated that genetic variation also has many ecological effects. In our study we aimed to test whether the patterns of response to the genetic diversity of a resident species differ between colonizing species of different growth forms and whether the response is affected by soil nutrients. Methods We established experimental stands of a common grass, Festuca rubra, harbouring three levels of genetic diversity (1, 6 or 18 clonal genotypes, referred to as genotypic diversity) under two soil nutrient levels. In the fourth year after the stands were established, we sowed a mixture of four colonizers into the stands: a stoloniferous legume (Trifolium repens), a broad-leaf tussock grass (Anthoxanthum odoratum), a large-rosette forb (Plantago lanceolata) and a small-rosette forb (Campanula rotundifolia). We observed species establishment and growth over 3 years. We tested whether colonization success depended on genotypic diversity, specific Festuca genotypes, soil nutrients and colonizer growth form. Important Findings The colonization success and biomass of the colonizers were significantly affected by the genotypic diversity and the genotype identity of the resident clonal grass. The response, however, differed between the colonizers. The strongest response to the genotypic diversity of the resident species was observed in the tussock grass with a growth form and architecture similar to the resident species. The large-rosette species responded in early stages of growth whereas the stoloniferous legume did not respond at all. The intraspecific genotypic diversity and genotype identity of the resident species play an important role in the assembly of plant communities.

scholarly journals EVALUATION OF SOIL NUTRIENT STATUS IN APPLE ORCHARDS LOCATED IN DIFFERENT ALTITUDES IN KALIKOT DISTRICT, NEPAL

2021 ◽  
Vol 5 (2) ◽  
pp. 99-103
Author(s):  
Dhruba Baral ◽  
Anup Paudel ◽  
Himal Acharya ◽  
Madhav Prasad Neupane
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Nutrients ◽  
Soil Depth ◽  
Block Design ◽  
Soil Nutrient ◽  
Soil Samples ◽  
Apple Orchards ◽  
Nitrogen And Phosphorus ◽  
Poor Soil

This study was conducted to assess the fertility status of different altitude of apple orchard and their effect upon soil nutrients and to study the relationship between different altitude and their availability. Seven different orchards located in 2800, 2700 2600, 2500, 2400, 2300 and 2200 at Apple Zone, Raskot, Kalikot were selected as treatments. They were replicated three times in Randomized Complete Block Design. Composite soil samples were collected in each study site from 0-3 ft soil depth in ‘W’ pattern from each plot. Analyses of soil samples were done in regional soil testing laboratory, Surkhet for chemical properties. There was a significant effect (p<0.05) of altitude on soil macronutrients except available potassium level. Maximum amounts of soil organic matter, acidic and soil rich in nitrogen and phosphorus were found in 2800 masl whereas more basic soil , poor soil organic matter and soil poor in nitrogen and phosphorus were found in 2200 masl. Result showed that in altitude of 2200 masl has poor soil nutrients compared to apple orchards in higher altitude. Kalikot is the top producer of apple in Nepal. This assessment will helps apple growers for adopting better nutrient management plan in their orchards according to the altitude in the district. Further, it is recommended to conduct soil nutrient assessments for all other apple growing regions in the country.

scholarly journals Multiple soil nutrient competition between plants, microbes, and mineral surfaces: model development, parameterization, and example applications in several tropical forests

2015 ◽  
Vol 12 (5) ◽  
pp. 4057-4106 ◽  
Author(s):  
Q. Zhu ◽  
W. J. Riley ◽  
J. Tang ◽  
C. D. Koven
Keyword(s):  
Tropical Forest ◽  
Tropical Forests ◽  
Soil Nutrients ◽  
Model Development ◽  
Soil Nutrient ◽  
Competition Model ◽  
Plant Roots ◽  
Mineral Surfaces ◽  
Nutrient Competition ◽  
Nitrogen And Phosphorus

Abstract. Soil is a complex system where biotic (e.g., plant roots, micro-organisms) and abiotic (e.g., mineral surfaces) consumers compete for resources necessary for life (e.g., nitrogen, phosphorus). This competition is ecologically significant, since it regulates the dynamics of soil nutrients and controls aboveground plant productivity. Here we develop, calibrate, and test a nutrient competition model that accounts for multiple soil nutrients interacting with multiple biotic and abiotic consumers. As applied here for tropical forests, the Nutrient COMpetition model (N-COM) includes three primary soil nutrients (NH4+, NO3−, and POx (representing the sum of PO43−, HPO42−, and H2PO4−)) and five potential competitors (plant roots, decomposing microbes, nitrifiers, denitrifiers, and mineral surfaces). The competition is formulated with a quasi-steady-state chemical equilibrium approximation to account for substrate (multiple substrates share one consumer) and consumer (multiple consumers compete for one substrate) effects. N-COM successfully reproduced observed soil heterotrophic respiration, N2O emissions, free phosphorus, sorbed phosphorus, and free NH4+ at a tropical forest site (Tapajos). The overall model posterior uncertainty was moderately well constrained. Our sensitivity analysis revealed that soil nutrient competition was primarily regulated by consumer-substrate affinity rather than environmental factors such as soil temperature or soil moisture. Our results imply that the competitiveness (from most to least competitive) followed this order: (1) for NH4+, nitrifiers ~ decomposing microbes > plant roots, (2) for NO3−, denitrifiers ~ decomposing microbes > plant roots, (3) for POx, mineral surfaces > decomposing microbes ~ plant roots. Although smaller, plant relative competitiveness is of the same order of magnitude as microbes. We then applied the N-COM model to analyze field nitrogen and phosphorus perturbation experiments in two tropical forest sites (in Hawaii and Puerto Rico) not used in model development or calibration. Under soil inorganic nitrogen and phosphorus elevated conditions, the model accurately replicated the experimentally observed competition among different nutrient consumers. Although we used as many observations as we could obtain, more nutrient addition experiments in tropical systems would greatly benefit model testing and calibration. In summary, the N-COM model provides an ecologically consistent representation of nutrient competition appropriate for land BGC models integrated in Earth System Models.

scholarly journals Nutrient resorption tightens plant nitrogen and phosphorus coupling and decreases with sulfur deposition as mediated by interannual precipitation in a meadow

2021 ◽  
Author(s):  
Xue Feng ◽  
Ruzhen Wang ◽  
Tianpeng Li ◽  
Jiangping Cai ◽  
Heyong Liu ◽  
...  
Keyword(s):  
Nutrient Availability ◽  
Soil Acidification ◽  
Soil Nutrient ◽  
Nutrient Resorption ◽  
Mean Annual Precipitation ◽  
Nitrogen And Phosphorus ◽  
Nutrient Mobilization ◽  
Soil Nutrient Availability ◽  
Green Leaves ◽  
S Deposition

Abstract Purpose Sulfur (S) deposition as a global change issue causes worldwide soil acidification, nutrient mobilization and marked changes in plant nutrition. Here, we investigated how S deposition would affect leaf nutrient resorption and how this effect varies with yearly fluctuations in precipitation. Methods In a semiarid meadow exposed to S addition, we measured nitrogen (N), phosphorus (P) and S concentrations in green and senescent leaves of a grass and a sedge and calculated nutrient resorption efficiencies (NuRE) across two years with contrasting precipitation (13% higher and 27% lower than long-term mean annual precipitation). Results Concentrations of N, P, and S in green and senescent leaves generally increased with S addition across the two years, with the exception of N and P concentrations in green leaves of the grass that showed no response or even decreased with S addition. The coupling relationships between N and P concentrations showed interannual variations and tightened by nutrient resorption, as evidenced by stronger N and P correlations in senescent leaves than in green leaves in the wet year. Leaf NuRE convergently decreased with S addition across the two years congruent with soil acidification and increased soil N, P and S availability, while NuRE was higher in the wet year due to lower soil nutrient availability herein. Conclusions This study provides new evidence on the role of nutrient resorption in tightening stoichiometric N:P relationships, and a three-dimensional feedback framework that plant nutrient resorption was favored by higher precipitation to sharpen its tradeoff with soil nutrient availability.

scholarly journals Ground-layer composition affects tree fine root biomass and soil nutrient availability in jack pine and black spruce forests under extreme drainage conditions

2017 ◽  
Vol 47 (4) ◽  
pp. 433-444 ◽  
Author(s):  
Marine Pacé ◽  
Nicole J. Fenton ◽  
David Paré ◽  
Yves Bergeron
Keyword(s):  
Soil Nutrients ◽  
Nutrient Availability ◽  
Root Biomass ◽  
Fine Root ◽  
Black Spruce ◽  
Soil Nutrient ◽  
Fine Root Biomass ◽  
Ground Layer ◽  
Soil Nutrient Availability ◽  
Layer Composition

In the boreal forest, long-lasting canopy gaps are associated with lichens on dry sites and with Sphagnum spp. on wet sites. We hypothesize that ground-layer composition plays a role in maintaining gaps through its effects on fine root biomass (diameter ≤ 2 mm) and soil nutrient availability. Along gradients of canopy openness in both jack pine (Pinus banksiana Lamb.) – lichen and black spruce (Picea mariana (Mill.) B.S.P.) – moss forests, the relationships between canopy closure, ground-layer composition, tree fine root biomass, and soil nutrients were analyzed and decomposed using path analysis. The effects of lichen and Sphagnum spp. removal on tree fine root biomass and soil nutrients were tested in situ. Although variations in pine fine root biomass were mainly explained by stand aboveground biomass, lichen removal locally increased fine root biomass by more than 50%, resin extractable soil potassium by 580%, and base cations by 180%. While Sphagnum cover was identified as a key driver of stand aboveground biomass reduction in paludified forest sites, its removal had no short-term effects on spruce fine root biomass and soil nutrients. Our results suggest that lichens, more than Sphagnum spp., affect tree growth via direct effects on soil nutrients. These two different patterns call for different silvicultural solutions to maintain productive stands.

scholarly journals Context dependency of insect and mammalian herbivore effects on tall thistle (Cirsium altissimum) populations

2018 ◽  
Vol 12 (3) ◽  
pp. 531-541
Author(s):  
F Leland Russell ◽  
Gregory R Houseman
Keyword(s):  
Population Growth ◽  
Seed Production ◽  
Soil Nutrients ◽  
Nutrient Availability ◽  
Growth Rates ◽  
Soil Nutrient ◽  
Context Dependency ◽  
Soil Nutrient Availability ◽  
Plant Populations ◽  
Population Growth Rates

Abstract Aims Identifying factors that drive variation in herbivore effects on plant populations can provide insight for explaining plant distributions and for limiting weeds. Abiotic resource availability to plants is a key explanation for variation in herbivore effects on individual plants, but the role of resources in determining herbivore effects on plant populations is largely unexplored. We tested the hypothesis that soil nutrient availability drives variation in insect and mammal herbivore effects on tall thistle (Cirsium altissimum) population growth. Methods In a Kansas USA restored tallgrass grassland that experienced prescribed fires, we manipulated soil nutrients, through fertilizer addition, and presence of insect and mammal herbivores, using combinations of insecticide and fencing, in experimental plots. Over 7 years, we quantified herbivore damage to reproductive tall thistles, tall thistle seed production and population growth rates. Important Findings Seed production was reduced by insect herbivores and increased by fertilizer addition, but treatment effects were independent. Herbivore effects on tall thistle population growth depended upon soil nutrients in only one of seven annual transitions. Herbivores reduced thistle population growth in two of three annual transitions that included prescribed fire, whereas they reduced population growth in only one of four transitions without fire. Soil nutrient availability does not provide a general explanation for variation in herbivore effects on tall thistle population growth rates. Disturbance regime may be a more important aspect of ecological context for influencing herbivore effects on tall thistle populations in mesic grasslands.

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