Contrasting responses of lichens and Vaccinium angustifolium to long-term acidification of a boreal forest ecosystem

1989 ◽  
Vol 67 (2) ◽  
pp. 579-588 ◽  
Author(s):  
Martha G. Scott ◽  
Thomas C. Hutchinson ◽  
Marilyn J. Feth
Keyword(s):  
Boreal Forest ◽  
Growth Parameters ◽  
Light Attenuation ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Forest Understory ◽  
Permanent Plots ◽  
Percent Cover ◽  
Vaccinium Angustifolium ◽  
Understory Species

Over a 5-year period, we investigated the effects of simulated acidic precipitation on boreal forest understory species. Percent cover, net photosynthetic rate, and growth of three species of subarctic lichens were evaluated. Throughout the growing season, Cladina stellaris, Cladina rangiferina, and Cladina mitis, along with the associated vascular perennial, Vaccinium angustifolium, received twice-monthly sprays of artificial rain adjusted to pH 5.6, 4.0, 3.5, 3.0, or 2.5 using a 2:1 ratio of sulfuric to nitric acids. Changes in percent cover of the flora in permanent plots were measured annually during treatment years and then for a 6th year to monitor postspray recovery. Following 5 years of spraying, combined cover values for the three lichen species had decreased by up to 27% in plots sprayed with rain of less than pH 4.0, while percent cover of V. angustifolium had increased by 55 %. Although losses in net photosynthesis of 65% occurred for lichens receiving rains of pH 2.5, differences were not significant and data were highly variable. However, increasing acidity of the sprays significantly suppressed mean podetial height and dry weight of C. stellaris and C. mitis. The effect on these lichens of shading by the potential competitor V. angustifolium was investigated in a companion study, and it was concluded that the growth suppression of C. stellaris was most likely related to rainfall acidity and not to light attenuation. Cladina mitis was more sensitive to low light levels. Although adversely affected by rain of pH 2.5, C. rangiferina showed stimulation of a number of growth parameters in plots sprayed with rain of pH 3.0. It was concluded that responses of boreal understory species are variable and complex, and that several species (i.e., C. rangiferina and V. angustifolium) are tolerant of rainfall of less than pH 3.5.

The response of the feather moss, Pleurozium schreberi, to 5 years of simulated acid precipitation in the Canadian boreal forest

1988 ◽  
Vol 66 (1) ◽  
pp. 82-88 ◽  
Author(s):  
Thomas C. Hutchinson ◽  
Martha G. Scott
Keyword(s):  
Boreal Forest ◽  
Dry Weight ◽  
Acid Precipitation ◽  
Permanent Plots ◽  
Pleurozium Schreberi ◽  
Forest Site ◽  
Percent Cover ◽  
Feather Moss ◽  
Lateral Branches ◽  
Canadian Boreal Forest

Permanent plots dominated by the feather moss, Pleurozium schreberi (Brid.) Mitt., were established at a Canadian boreal forest site to study the effects of simulated acid precipitation on percent cover, growth, and photosynthesis of vegetation. For a 5-year period, beginning in 1981, plots of P. schreberi received twice-monthly sprayings of simulated rain, adjusted to pH 5.6, 4.0, 3.5, 3.0, or 2.5 with a 2:1 molar mixture of sulfuric and nitric acids. Unsprayed plots were also monitored. Almost complete elimination of the moss had occurred in the plots sprayed with pH 2.5 by the end of the 2nd year of treatment, and substantial decreases in cover were also recorded at pH 3.0 and 3.5 over the 5 years. Significant reductions of up to 75% in total and living frond height and dry weight were recorded at pH 3.5 and lower. Lateral branches produced in acid-treated plots also were stunted and few in number. This decline in growth and percent cover of P. schreberi may have resulted from the decreased net photosynthetic rates measured in the field and would be accelerated by increased rates of evapotranspiration in the altered moss microhabitat.

scholarly journals Allometric Equations for the Aboveground Biomass of Selected Common Eastern Hardwood Understory Species

2010 ◽  
Vol 27 (4) ◽  
pp. 160-165 ◽  
Author(s):  
Yvette L. Dickinson ◽  
Eric K. Zenner
Keyword(s):  
Aboveground Biomass ◽  
Dry Weight ◽  
Vaccinium Corymbosum ◽  
Allometric Equations ◽  
Forest Understory ◽  
Rosa Multiflora ◽  
Basal Diameter ◽  
Understory Species ◽  
Elaeagnus Umbellata ◽  
Fit Index

Abstract Allometric equations were formulated for predicting the aboveground biomass of six groups of forest understory species (Elaeagnus umbellata Thunb.], blueberry [Vaccinium angustifolium Aiton, Vaccinium corymbosum L., and Vaccinium pallidum Aiton], hawthorn [Crataegus spp.], honeysuckle [Lonicera spp.], multiflora rose [Rosa multiflora Thunb.], and viburnum [Viburnum acerifolium L. and Viburnum dentatum L.]) common to Eastern hardwoods using basal diameter and/or height. As measured by fit index, basal diameter or height alone explained between 51 and 93% of the variation in oven-dry weight; this increased to 75‐96% when both basal diameter and height were used as predictors. Data were collected at four sites throughout Pennsylvania, but an evaluation of the importance of site as a blocking factor found site not to be statistically significant; therefore, the equations presented here may be used in a variety of forested sites within the greater mid-Atlantic region.

Regrowth of forest understory species following seasonal burning

1988 ◽  
Vol 66 (1) ◽  
pp. 150-155 ◽  
Author(s):  
Marguerite A. Flinn ◽  
Ross W. Wein
Keyword(s):  
Fold Increase ◽  
Forest Stand ◽  
Forest Understory ◽  
Stem Number ◽  
Tree Seedling ◽  
Vaccinium Angustifolium ◽  
Understory Species ◽  
Number Of Stems ◽  
Maianthemum Canadense ◽  
Vaccinium Myrtilloides

Small experimental plots in mixed-wood stands of the Acadian Forest were burned in the spring, summer, and autumn to obtain an estimate of the regrowth potential of common forest understory species. The number of stems was measured before burning and then monthly for 5 months thereafter. Supportive experiments on seasonal transplanting were conducted at the same time to determine regrowth potential after interspecific competition had been removed. Regrowth potential of species varied among seasonal burning treatments as expected and was strongest for Maianthemum canadense, Vaccinium myrtilloides, Andromeda glaucophylla, Vaccinium angustifolium, Viburnum cassinoides, and Betula populifolia. These species, which showed a 10-fold increase in stem number, could compete successfully with tree seedling number and composition and thus ultimately alter forest stand composition.

scholarly journals Growth Analysis and Photosynthesis Measurements of Cucumber Seedlings Grown under Light with Different Red to Far-red Ratios

HortScience ◽  
2016 ◽  
Vol 51 (7) ◽  
pp. 843-846 ◽  
Author(s):  
Toshio Shibuya ◽  
Ryosuke Endo ◽  
Yoshiaki Kitaya ◽  
Saki Hayashi
Keyword(s):  
Leaf Area ◽  
Growth Parameters ◽  
Weight Ratio ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Unit Leaf Area ◽  
Cucumber Seedlings ◽  
Unit Leaf ◽  
Net Assimilation ◽  
Normal Light

Light with a higher red to far-red ratio (R:FR) than sunlight reduces plant growth, but the cause has not been firmly established. In the present study, cucumber seedlings were grown under normal light (similar to sunlight; R:FR = 1.4) from metal-halide lamps or high-R:FR light (R:FR = 4.3) created by transmitting their light through FR-absorbing film, and then their growth parameters and photosynthesis were compared. The relative growth rate (RGR) at high R:FR was 92% of that under normal R:FR, although the net assimilation rate (NAR) did not differ between the treatments, indicating that changes in net photosynthesis per unit leaf area did not cause the growth inhibition at high R:FR. The CO2 exchange per unit leaf area did not differ between the treatments, which supports this hypothesis. The leaf area ratio (LAR) of total plant dry weight of high R:FR seedlings to that of normal R:FR seedlings was also 92%. This suggests that growth suppression in the high R:FR seedlings was caused mainly by decreased LAR. The specific leaf area (SLA) and leaf weight ratio (LWR), components of LAR, under high-R:FR light were 89% and 105%, respectively, of those under normal light, indicating that the smaller LAR at high R:FR mainly results from suppressed leaf enlargement per unit leaf dry matter.

scholarly journals Biostimulant Effects of an Aqueous Extract of Duckweed (Lemna minor L.) on Physiological and Biochemical Traits in the Olive Tree

Agriculture ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1299
Author(s):  
Luca Regni ◽  
Daniele Del Buono ◽  
Begoña Miras-Moreno ◽  
Biancamaria Senizza ◽  
Luigi Lucini ◽  
...  
Keyword(s):  
Chlorophyll Content ◽  
Aqueous Extract ◽  
Plant Biomass ◽  
Growth Parameters ◽  
Lemna Minor ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Co2 Concentration ◽  
Olive Tree ◽  
Water Volume

Biostimulants are becoming increasingly popular in agriculture for their ability to induce beneficial effects in crops, paving the way towards the identification of new materials with biostimulant potential. This study evaluated the potential of different concentrations of an aqueous extract (0.25%, 0.50%, and 1.00%, dry weight/water volume, respectively) obtained from duckweed (Lemna minor L.) to stimulate olive plants. Leaf net photosynthesis (Pn), leaf transpiration rate (E), stomatal conductance (gs), sub-stomatal CO2 concentration (Ci), chlorophyll content and other plant growth parameters were investigated. As a result, the extract improved Pn, gs, Ci, chlorophyll content and plant biomass production (leaf fresh and dry weight). Furthermore, the duckweed extract generally increased the uptake of nitrogen (N), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe) and zinc (Zn), while it did not influence the content of sodium (Na), manganese (Mn) and copper (Cu). The untargeted metabolomic profiling of the extract revealed the presence of signalling compounds (including phytohormones), phenolics and glutathione. Such broad diversity of bioactives may support the stimulatory potential observed in olive. In summary, this study revealed for the first time that duckweed could be seen as a promising species to obtain extracts with biostimulant properties in olive trees.

scholarly journals Hiding from the climate: Characterizing microrefugia for boreal forest understory species

2019 ◽  
Vol 26 (2) ◽  
pp. 471-483 ◽  
Author(s):  
Caroline Greiser ◽  
Johan Ehrlén ◽  
Eric Meineri ◽  
Kristoffer Hylander
Keyword(s):  
Boreal Forest ◽  
Forest Understory ◽  
Understory Species

Effect of rhizobacteria strains on the induction of resistance in barley genotypes against Cochliobolus sativus

2020 ◽  
Vol 13 (2) ◽  
pp. 83-92 ◽  
Author(s):  
A. Adam
Keyword(s):  
Plant Growth ◽  
Pseudomonas Putida ◽  
Growth Parameters ◽  
Disease Incidence ◽  
Dry Weight ◽  
Cochliobolus Sativus ◽  
Resistance Level ◽  
Wet Weight ◽  
Number Of Leaves ◽  
Barley Genotypes

SummaryEnhancement of the resistance level in plants by rhizobacteria has been proven in several pathosystems. This study investigated the ability of four rhizobacteria strains (Pseudomonas putida BTP1 and Bacillus subtilis Bs2500, Bs2504 and Bs2508) to promote the growth in three barley genotypes and protect them against Cochliobolus sativus. Our results demonstrated that all tested rhizobacteria strains had a protective effect on barley genotypes Arabi Abiad, Banteng and WI2291. However, P. putida BTP1 and B. subtilis Bs2508 strains were the most effective as they reduced disease incidence by 53 and 38% (mean effect), respectively. On the other hand, there were significant differences among the rhizobacteria-treated genotypes on plant growth parameters, such as wet weight, dry weight, plant height and number of leaves. Pseudomonas putida BTP1 strain was the most effective as it significantly increased plant growth by 15-32%. In addition, the susceptible genotypes Arabi Abiad and WI2291 were the most responsive to rhizobacteria. This means that these genotypes have a high potential for increase of their resistance against the pathogen and enhancement of plant growth after the application of rhizobacteria. Consequently, barley seed treatment with the tested rhizobacteria could be considered as an effective biocontrol method against C. sativus.

scholarly journals Growth and Antioxidant Responses in Iron-Biofortified Lentil under Cadmium Stress

Toxics ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 182
Author(s):  
Ruchi Bansal ◽  
Swati Priya ◽  
Harsh Kumar Dikshit ◽  
Sherry Rachel Jacob ◽  
Mahesh Rao ◽  
...  
Keyword(s):  
Growth Parameters ◽  
Dry Weight ◽  
Cadmium Stress ◽  
Antioxidant Enzyme Activities ◽  
Limited Information ◽  
Cd Stress ◽  
Fresh Weight ◽  
Cd Uptake ◽  
Cd Tolerance ◽  
Controlled Conditions

Cadmium (Cd) is a hazardous heavy metal, toxic to our ecosystem even at low concentrations. Cd stress negatively affects plant growth and development by triggering oxidative stress. Limited information is available on the role of iron (Fe) in ameliorating Cd stress tolerance in legumes. This study assessed the effect of Cd stress in two lentil (Lens culinaris Medik.) varieties differing in seed Fe concentration (L4717 (Fe-biofortified) and JL3) under controlled conditions. Six biochemical traits, five growth parameters, and Cd uptake were recorded at the seedling stage (21 days after sowing) in the studied genotypes grown under controlled conditions at two levels (100 μM and 200 μM) of cadmium chloride (CdCl2). The studied traits revealed significant genotype, treatment, and genotype × treatment interactions. Cd-induced oxidative damage led to the accumulation of hydrogen peroxide (H2O2) and malondialdehyde in both genotypes. JL3 accumulated 77.1% more H2O2 and 75% more lipid peroxidation products than L4717 at the high Cd level. Antioxidant enzyme activities increased in response to Cd stress, with significant genotype, treatment, and genotype × treatment interactions (p < 0.01). L4717 had remarkably higher catalase (40.5%), peroxidase (43.9%), superoxide dismutase (31.7%), and glutathione reductase (47.3%) activities than JL3 under high Cd conditions. In addition, L4717 sustained better growth in terms of fresh weight and dry weight than JL3 under stress. JL3 exhibited high Cd uptake (14.87 mg g−1 fresh weight) compared to L4717 (7.32 mg g−1 fresh weight). The study concluded that the Fe-biofortified lentil genotype L4717 exhibited Cd tolerance by inciting an efficient antioxidative response to Cd toxicity. Further studies are required to elucidate the possibility of seed Fe content as a surrogacy trait for Cd tolerance.

scholarly journals Phytoextraction of Lead Using a Hedge Plant [Alternanthera bettzickiana (Regel) G. Nicholson]: Physiological and Biochemical Alterations through Bioresource Management

2021 ◽  
Vol 13 (9) ◽  
pp. 5074
Author(s):  
Urooj Kanwal ◽  
Muhammad Ibrahim ◽  
Farhat Abbas ◽  
Muhammad Yamin ◽  
Fariha Jabeen ◽  
...  
Keyword(s):  
Citric Acid ◽  
Growth Parameters ◽  
Cost Effective ◽  
Dry Weight ◽  
Citric Acid Concentration ◽  
Biochemical Alterations ◽  
Biomass Plant ◽  
Environmentally Friendly Approach ◽  
Pb Concentration

Phytoremediation is a cost-effective and environmentally friendly approach that can be used for the remediation of metals in polluted soil. This study used a hedge plant–calico (Alternanthera bettzickiana (Regel) G. Nicholson) to determine the role of citric acid in lead (Pb) phytoremediation by exposing it to different concentrations of Pb (0, 200, 500, and 1000 mg kg−1) as well as in a combination with citric acid concentration (0, 250, 500 µM). The analysis of variance was applied on results for significant effects of the independent variables on the dependent variables using SPSS (ver10). According to the results, maximum Pb concentration was measured in the upper parts of the plant. An increase in dry weight biomass, plant growth parameters, and photosynthetic contents was observed with the increase of Pb application (200 mg kg−1) in soil while a reduced growth was experienced at higher Pb concentration (1000 mg kg−1). The antioxidant enzymatic activities like superoxide dismutase (SOD) and peroxidase (POD) were enhanced under lower Pb concentration (200, 500 mg kg−1), whereas the reduction occurred at greater metal concentration Pb (1000 mg kg−1). There was a usual reduction in electrolyte leakage (EL) at lower Pb concentration (200, 500 mg kg−1), whereas EL increased at maximum Pb concentration (1000 mg kg−1). We concluded that this hedge plant, A. Bettzickiana, has the greater ability to remediate polluted soils aided with citric acid application.

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