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1
Gao, Yu-Fu, Li-Ping Rong, Dong-Hui Zhao, Jia-Qi Zhang, and Jia-Shuo Chen. "Effects of simulated acid rain on the photosynthetic physiology of Acer ginnala seedlings." Canadian Journal of Forest Research 51, no. 1 (January 2021): 18–24. http://dx.doi.org/10.1139/cjfr-2020-0091.
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Extensive areas in China have been receiving high levels of acid rain. Acid rain affects plant growth by reducing the chlorophyll content, destroying leaf structure, and hindering photosynthesis. Acer ginnala Maxim. has a high economic, ornamental, and medicinal value. To clarify the acid rain resistance mechanism of maple trees, the chlorophyll content, gas exchange parameters, and chlorophyll fluorescence parameters were measured in the leaves of 2-year-old Acer ginnala seedlings 0, 15, and 30 days after simulated acid rain at pH 5.6, 5.0, 4.5, 4.0, 3.5, and 2.5. The results showed that the relative content of chlorophyll gradually decreased with the increasing acidity. The net photosynthetic rate (Pn) decreased with the increasing acidity, and the difference among the treatments was significant except for between pH 5.0 and the control. The stomatal conductance at pH < 5.0 was significantly lower than that of the control, and the intercellular carbon dioxide (CO2) concentration of the leaves with the pH < 4.5 treatments was significantly lower than that of the control. As the acidity increased, both Fv/Fm and Fv/F0 (Fv, variable fluorescence; Fm, maximum fluorescence; F0, initial fluorescence) decreased. The difference in the photosynthetic performance index based on the absorbed light energy (PIabs) between the pH 5.0 treatment and the control was not significant during the three periods after the simulated acid rain stress, whereas in the other treatments, this index was significantly lower than that of the control. Our results indicated that under mild acid rain (pH > 4.0) stress, the chlorophyll content, gas exchange parameters, and chlorophyll fluorescence parameters of Acer ginnala changed little, whereas in the other treatments, especially the severe acid rain (pH < 3.0) treatment, these indices showed significant changes that had a severe impact on plant growth and development.
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Zhang, Yuyang, Tao Yu, Wenbao Ma, Buddhi Dayananda, Kenji Iwasaki, and Junqing Li. "Morphological, Physiological and Photophysiological Responses of Critically Endangered Acer catalpifolium to Acid Stress." Plants 10, no. 9 (September 19, 2021): 1958. http://dx.doi.org/10.3390/plants10091958.
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Acid rain deposition (AR) has long-lasting implications for the community stability and biodiversity conservation in southwest China. Acer catalpifolium is a critically endangered species in the rain zone of Western China where AR occurs frequently. To understand the effects of AR on the morphology and physiology of A. catalpifolium, we conducted an acid stress simulation experiment for 1.5 years. The morphological, physiological, and photosynthetic responses of A. catalpifolium to the acidity, composition, and deposition pattern of acid stress was observed. The results showed that simulated acid stress can promote the growth of A. catalpifolium via the soil application mode. The growth improvement of A. catalpifolium under nitric-balanced acid rain via the soil application mode was greater than that of sulfuric-dominated acid rain via the soil application mode. On the contrary, the growth of A. catalpifolium was significantly inhibited by acid stress and the inhibition increased with the acidity of acid stress applied via leaf spraying. The inhibitory impacts of nitric-balanced acid rain via the leaf spraying of A. catalpifolium were greater than that of sulfur-dominant acid rain via leaf spraying. The observations presented in this work can be utilized for considering potential population restoration plans for A. catalpifolium, as well as the forests in southwest China.
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Kim, Y. T., and R. H. Leech. "Effects of Climatic Conditions on Sap Flow in Sugar Maple." Forestry Chronicle 61, no. 4 (August 1, 1985): 303–7. http://dx.doi.org/10.5558/tfc61303-4.
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Temperature, sunlight and precipitation were studied to examine their influence on sugar maple (Acer saccharum Marsh) sap flow over a five-year period. Temperature was the most important climatic factor influencing the amount of sap flow. Sunlight also increased the sap flow, but rain one day before the sap collection reduced it.
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Roberts, Mark R., and Norman L. Christensen. "Vegetation variation among mesic successional forest stands in northern lower Michigan." Canadian Journal of Botany 66, no. 6 (June 1, 1988): 1080–90. http://dx.doi.org/10.1139/b88-154.
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Vegetation composition of the shrub–tree and herb layers was sampled in 70 successional aspen (Populus tremuloides and Populus grandidentata) stands of different ages (1–90 years) on a variety of sites in northern lower Michigan. Physical and chemical characteristics of soil profiles were also measured at each site. Three stand groupings were identified based on site conditions and detrended correspondence analysis (DCA) ordination of the vegetation. Sandy dry-mesic soils support forests of Acer rubrum, Quercus rubra, Pinus resinosa, and Pinus strobus. On lowland sandy soils with a fluctuating water table, Pinus strobus, Abies balsamea, Viburnum lentago, and Viburnum cassinoides are important. Mesic soils with stratified calcareous layers or clay till substrates support Acer saccharum, Fagus grandifolia, Tilia americana, Fraxinus americana, Ostrya virginiana, and Acer pensylvanicum. Canonical correlation analysis (CCA) was used to compare DCA scores with soil variables; first-axis DCA scores were correlated with a suite of soil variables and stand age was correlated with second or third DCA axis scores. Separate DCA ordinations of the dry-mesic and mesic groups revealed successional relations on these sites. On dry-mesic sites, Pinus resinosa and Pinus strobus increase in importance with stand age, while Prunus serotina, Prunus virginiana, Prunus pensylvanica, and the aspens decrease. On mesic sites, early successional species include the aspens, Corylus cornuta, Prunus serotina, and Prunus pensylvanica. Fagus grandifolia, Acer pensylvanicum, Quercus rubra, Viburnum acerifolium, Betula papyrifera, Acer rubrum, and Tilia americana are more abundant in mature mesic-site stands. Ordinations of the herb data were remarkably similar to those for trees and shrubs except on dry-mesic sites. Much of the residual variability in vegetation not accounted for by site conditions and stand age is probably related to historical factors such as the nature of disturbance and variations in seed rain.
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Yan, Qiaoling, Qun Gang, and Jiaojun Zhu. "Size-Dependent Patterns of Seed Rain in Gaps in Temperate Secondary Forests, Northeast China." Forests 10, no. 2 (February 4, 2019): 123. http://dx.doi.org/10.3390/f10020123.
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Secondary forests have become the major forest type worldwide, and are experiencing various disturbances and exhibiting obvious vegetation degradation (e.g., reduced biodiversity and decreased productivity) compared with primary forests. Forest gap is a common small-scale disturbance in secondary forests. Promoting natural regeneration under gap disturbance is an important approach to recover biodiversity and ecosystem services for temperate secondary forests. The gap size is the crucial characteristic controlling natural regeneration of many tree species. However, little is known about the spatiotemporal pattern of seed rain for gravity-dispersed and wind-dispersed tree species in gaps of varying sizes. The objectives of this study were to determine how seed rain of dominant tree species depend on gap size, and consequently, to explore some gap-based silviculture solutions for restoring secondary forests from the view of seed dispersal. The spatial distribution of seed rain in gaps with three sizes (large gaps of 250–350 m2, medium gaps of 150–250 m2, and small gaps of < 150 m2), the temporal dynamics of seed rain over three years, and the relationship between seed rain and soil seed banks were explored in temperate secondary forests. The results showed that more than 90% of the seeds in seed rain were wind-dispersed, and their seed rain density and the contribution of seed rain to soil seed bank in medium gaps reached the highest (p = 0.03). The results suggest that establishing medium-sized gaps (i.e., gap size with 150–250 m2) in the secondary forests is more favorable for improving the natural regeneration potential (arrival of seeds and forming soil seed bank) of gap-dependent and wind-dispersed species (e.g., Acer mono) in gaps.
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Gaber, B. A., and T. C. Hutchinson. "The neutralisation of acid rain by the leaves of four boreal forest species." Canadian Journal of Botany 66, no. 9 (September 1, 1988): 1877–82. http://dx.doi.org/10.1139/b88-256.
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A field study was carried out in the boreal forest of Ontario to measure the neutralisation response of the leaves of Cornus canadensis, Aralia nudicaulis, Maianthemum canadense, and Acer spicatum to simulated acid rain. Plots of each species were sprayed with pH 5.6, 3.8, or 3.2 rain, and the pH of the raindrops on the leaves and on Parafilm (control) was measured with a microelectrode at 15-min intervals until the leaves dried. Species differed in their ability to neutralise the rain, with C. canadensis consistently neutralising acidic raindrops the most. The neutralisation response varied greatly between pH treatments, with greatest neutralisation occurring at the most acidic pH treatment. Raindrop neutralisation primarily took place within the first few minutes following the spray. For this reason, the dissolution of basic particulates on the leaf surface was probably responsible for the rapid changes in raindrop pH, while slower changes may reflect cation exchange processes with the cell walls. Weather conditions determined the rate of evaporation of the raindrops, and this affected their acidity. High rates of evaporation reduced the time available for leaf surface – raindrop interactions and are probably responsible for the acidification observed in some plots.
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Beckage, Brian, James S. Clark, Barton D. Clinton, and Bruce L. Haines. "A long-term study of tree seedling recruitment in southern Appalachian forests: the effects of canopy gaps and shrub understories." Canadian Journal of Forest Research 30, no. 10 (October 1, 2000): 1617–31. http://dx.doi.org/10.1139/x00-075.
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We examined the importance of intermediate-sized gaps and a dense shrub layer on tree seedling recruitment in a southern Appalachian deciduous forest. We created 12 canopy gaps under two contrasting understory conditions: 6 gaps were dominated by the dense, shade-producing shrub, Rhododendron maximum L., while the remaining gaps were relatively open. Density of first-year and >first-year seedlings was monitored for 5 years in transects extending from adjacent undisturbed forest through the experimental gaps. We concurrently measured the understory light environment, soil moisture, litter biomass, and seed rain. Neither species diversity nor richness consistently increased following gap formation. Acer rubrum L. responded consistently to canopy gaps with increased seedling densities while most other species, including both shade-tolerant and shade-intolerant species, did not. Seedling densities were especially low and unresponsive to gap formation in areas dominated by R. maximum. Understory light levels were consistently low beneath R. maximum and did not increase with canopy gap formation. Our results suggest that dense shrub cover can neutralize recruitment opportunities in canopy gaps, that seed rain often limits recruitment in gaps, and that canopy gaps that are larger or include understory disturbance are needed to maintain diversity in these forests.
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Zhang, Yuyang, Cheng Tian, Tao Yu, Buddhi Dayananda, Brendan Fu, Samiddhi L. Senaratne, Cuiyun Wu, and Junqing Li. "Differential effects of acid rain on photosynthetic performance and pigment composition of the critically endangered Acer amplum subsp. catalpifolium." Global Ecology and Conservation 30 (October 2021): e01773. http://dx.doi.org/10.1016/j.gecco.2021.e01773.
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Rodinkova, V. V. "Аеропалінологічний спектр м. Дніпропетровськ як основа профілактики сезонної алергії." Visnyk of Dnipropetrovsk University. Biology, medicine 4, no. 1 (February 21, 2013): 3–9. http://dx.doi.org/10.15421/021314.
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Hay fever is important allergenic complain with number of patients rising year by year. Ukraine holds the leading positions in Europe in accordance with pollinosis morbidity. Therefore, it’s important to determine regional pollen spectrum for all five climatic and geographical zones of the country having certain variety of plants’ allergens. There are just a few cities with a constant pollen monitoring carried out in Ukraine. They are Vinnytsia, Kyiv, Odessa and Lviv. Palynological range of other Ukrainian cities remains unknown or poorly studied. Dnipropetrovsk – Ukrainian city with location in the Central part of the country in the Steppe zone – isn’t exception as well. Thus, the aim of our study was to determine the pattern of airborne pollen distribution and pollen calendar creation for the city of Dnipropetrovsk. Pollen count obtained at Vinnytsia National Pirogov Memorial Medical University (VNMU) by Aerobiology Research Group. Study was held in 2010 from the 17th of March till the 20th of October on daily basis employed volumetric methods using the Burkard trap. It stands on the roof of the Dnipropetrovsk Municipal hospital at 20 meters of a relative height above ground. The air samples were sent by currier mail on weekly basis from Dnipropetrovsk to Vinnytsia for the research term. 51 pollen types were determined during the study period. The aeropalinological research was done for the Dnipropetrovsk at first. Study was conducted in association with the European Aeroallergen Network (EAN). The EAN tools and the software package “Statistica 5.5” were used for data statistical analysis. The study showed prevalence of the airborne herbal pollen types in Dnipropetrovsk. The “weeds : trees” pollen ratio was «88 : 12». Most abundant pollen rain (59% of total annual pollen count) was produced by Ambrosia. The second position with 6% was held by Amaranthus / Chenopodiaceae pollen group and Urtica dioica pollen. Artemisia and other representatives of Asteraceae constituted of 5% each. The most abundant tree pollen rain (4% from total annual count) was produced by the Populus species. Betula pollen was the next having up 2% of annual pollen rain in Dnipropetrovsk. As can be seen, the first arboreal spring-summer pollination wave was not massive in Dnipropetrovsk. It was represented by Populus, Betula, Acer, Fraxinus, Quercus, Ulmus, Pinus, Juglans pollen spread in the end of March, whole April and the first weeks of May mostly. However, the second wave was intensively seen from the mid of July till the mid of October. Important airborne pollen producing taxa were Artemisisia, Ambrosia, Asteraceae, Chenopodiaceae, Urtica, Plantago, Polygonaceae pollen at that time. Important airborne pollen allergens of Poaceae family (grasses) held the 7th position in the total annual pollen rain and were recorded between two pollination waves from the mid of May till the end of June mostly. The worst period for the patients was associated with the Betula, Acer and Quercus pollination from 13th of April till the mid of May and with Ambrosia and Artemisia pollination from 28th of July, till September, 30. The present airborne pollen calendar should be considered while diagnosing the hay fever symptoms in sensitive patients. It’s important to continue the pollen count and control in Dnіpropetrovsk due to constant changing of climatic and anthropogenic conditions impacting the pollen production and release.
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Tauer, Pamela K., and Janet C. Cole. "Effect of Fabric and Plastic Containers on Plant Growth and Root Zone Temperatures of Four Tree Species." Journal of Environmental Horticulture 27, no. 3 (September 1, 2009): 145–48. http://dx.doi.org/10.24266/0738-2898-27.3.145.
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Abstract Live oak (Quercus virginiana Mill.), red maple (Acer rubrum L.), and sweet gum (Liquidambar styraciflua L.) trees were planted in #7 fabric or plastic containers on April 18, 2004, and grown for two growing seasons. Live oak and golden rain tree (Koelreuteria paniculata Laxm.) trees were planted in #10 fabric or plastic containers on May 6, 2005, and harvested the following summer. Plant height, canopy width, and caliper were measured periodically, and root zone temperatures were recorded at 30-min intervals throughout each study. In the 2004 planting, live oak height and canopy width increased more for plants in plastic containers than for those in fabric containers from May to July 2004. In contrast, no difference in live oak height or canopy width growth occurred between container types from July to September 2004, but trunk caliper increased more in plastic than in fabric containers during this time interval. No differences between container treatments were noted for any measured parameter for red maple or sweet gum trees planted in 2004 or for golden rain tree or live oak trees planted in 2005 at any measurement interval during the study. Average monthly high and low substrate temperatures were similar between the two container types throughout the study. Fabric containers appear to be a reasonable alternative to plastic containers for above ground nursery crop production, although small differences in growth occur for some species.
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Garten, Charles T., and Paul J. Hanson. "Foliar retention of 15N-nitrate and 15N-ammonium by red maple (Acer rubrum) and white oak (Quercus alba) leaves from simulated rain." Environmental and Experimental Botany 30, no. 3 (July 1990): 333–42. http://dx.doi.org/10.1016/0098-8472(90)90045-6.
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Wright, Amy N., Alex X. Niemiera, J. Roger Harris, and Robert D. Wright. "Preplant Lime and Micronutrient Amendments to Pine Bark Affect Growth of Seedlings of Nine Container-grown Tree Species." HortScience 34, no. 4 (July 1999): 669–73. http://dx.doi.org/10.21273/hortsci.34.4.669.
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The objective of this study was to determine the effects of lime and micronutrient amendments on growth of seedlings of nine container-grown landscape tree species in two pine bark substrates with different pHs. Acer palmatum Thunb. (Japanese maple), Acer saccharum Marsh. (sugar maple), Cercis canadensis L. (redbud), Cornus florida L. (flowering dogwood), Cornus kousa Hance. (kousa dogwood), Koelreuteria paniculata Laxm. (golden-rain tree), Magnolia ×soulangiana Soul.-Bod. `Lennei' (magnolia), Nyssa sylvatica Marsh. (blackgum), and Quercus palustris Müenchh. (pin oak) were grown from seed in two pine bark substrates with different pHs (pH 4.7 and 5.1) (Expt. 1). Preplant amendment treatments for each of two pine (Pinus taeda L.) bark sources were: with and without dolomitic limestone (3.6 kg·m–3) and with and without micronutrients (0.9 kg·m–3), and with and without micronutrients (0.9 kg·m–3), supplied as Micromax. Seedlings were harvested 12 and 19 weeks after seeds were planted, and shoot dry weight and tree height were determined. The same experiment was repeated using two of the nine species from Expt. 1 and pine bark substrates at pH 5.1 and 5.8 (Expt. 2). Seedling shoot dry weight and height were measured 11 weeks after planting. For both experiments, pine bark solutions were extracted using the pour-through method and analyzed for Ca, Mg, Fe, Mn, Cu, and Zn. Growth of all species in both experiments was greater in micronutrient-amended than in lime-amended bark. In general, adding micronutrients increased nutrient concentrations in the pine bark solution, while adding lime decreased them. Effect of bark type on growth in Expt. 1 was variable; however, in Expt. 2, growth was greater in the low pH bark than in the high pH bark. In general, nutrient concentrations in bark solutions were higher in low pH bark than in high pH bark for both experiments. Under the pH conditions of this experiment, micronutrient additions stimulated growth whereas a lime amendment did not.
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Cleavitt, Natalie L., John J. Battles, Timothy J. Fahey, and Joel D. Blum. "Determinants of survival over 7 years for a natural cohort of sugar maple seedlings in a northern hardwood forest." Canadian Journal of Forest Research 44, no. 9 (September 2014): 1112–21. http://dx.doi.org/10.1139/cjfr-2014-0177.
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The regeneration ecology of sugar maple (Acer saccharum Marsh.) has been impacted by acid rain leaching of base cations from the soils throughout much of its range. We tracked the survival and causes of death for a natural cohort of sugar maple seedlings across 22 sites in the Hubbard Brook Valley in New Hampshire, USA, where soil acidification has been documented. Survival over 7 years averaged 3.4%; however, significant differences in survival were observed among sites, which were classified into three main groups based on the shape of their survival curves. These site groups differed in position on the landscape, seedling nutrition and leaf size, and the prevalence of damage agents, but not in soil Ca. First-season mortality was high (71%), and the main damage agents were fungal infection (Rhizoctonia spp.) and caterpillar herbivory (Geometridae). Other principal causes of mortality in order of importance were winter injury, mechanical damage, and rodent (Myodes gapperi Vigors, 1830) tunneling, and all damage agents varied significantly in severity between years. This study highlights the importance of landscape-level variation in biotic factors for predicting sugar maple regeneration success. Predictions of sugar maple regeneration will require a better understanding of controls on initial seedling growth and the suite of biotic agents that damages seedlings.
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Sisaphaithong, Thongkhoun, Phathana Sengounkeo, Sengdala Mounnalath, Gerard Kelly, and Jeremy Badgery-Parker. "Low Cost Protective Structures Providing Suitable Growing Conditions for Vegetable Crops Year-Round in the Tropics." Proceedings 36, no. 1 (April 10, 2020): 213. http://dx.doi.org/10.3390/proceedings2019036213.
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Vegetable production is an important activity, source of food and income for farmers. Vegetables are grown in many regions in Lao PDR. There is a large range of agro-climatic conditions between the two seasons - wet and dry. The dry season is suitable and favourable for vegetable production. However, the wet season has high temperature, high relative humidity, high soil moisture content and heavy rain. These conditions cause several negative impacts for vegetable production such as, low vegetable productivity and poor quality. Higher application of pesticides can also lead to food safety issues and high input cost of cultivation. These challenges could impact to inadequate domestic supply of vegetables in rainy season, low economic returns from vegetable production, and increased imports of vegetable from other countries. NAFRI and ACIAR have cooperated to research and develop a design of greenhouse structure that is economical and provides suitable growing conditions in the wet season to help farmers to mitigate the multiple constraints and successfully grow vegetables year-round. The new design was constructed and tested with several types of vegetable crops including coriander, lettuce, spring onion and tomato during 2015–2018. Evaluation was made against ambient conditions, crop needs and also a comparison with several other protected cropping designs was conducted. The new design provides improved, cooler and more suitable growing conditions for a range of crops, increasing productivity and quality of vegetable in the wet season.
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Schurman, Jonathan S., and Sean C. Thomas. "Linking Soil CO2 Efflux to Individual Trees: Size-Dependent Variation and the Importance of the Birch Effect." Soil Systems 5, no. 1 (January 27, 2021): 7. http://dx.doi.org/10.3390/soilsystems5010007.
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Soil CO2 efflux (FCO2) is a major component of the terrestrial carbon (C) cycle but challenges in explaining local variability hamper efforts to link broad-scale fluxes to their biotic drivers. Trees are the dominant C source for forest soils, so linking tree properties to FCO2 could open new avenues to study plant-soil feedbacks and facilitate scaling; furthermore, FCO2 responds dynamically to meteorological conditions, complicating predictions of total FCO2 and forest C balance. We tested for proximity effects of individual Acer saccharum Marsh. trees on FCO2, comparing FCO2 within 1 m of mature stems to background fluxes before and after an intense rainfall event. Wetting significantly increased background FCO2 (6.4 ± 0.3 vs. 8.6 ± 0.6 s.e. μmol CO2 m−2s−1), with a much larger enhancement near tree stems (6.3 ± 0.3 vs. 10.8 ± 0.4 μmol CO2 m−2s−1). FCO2 varied significantly among individual trees and post-rain values increased with tree diameter (with a slope of 0.058 μmol CO2 m−2s−1cm−1). Post-wetting amplification of FCO2 (the ‘Birch effect’) in root zones often results from the improved mobility of labile carbohydrates and further metabolization of recalcitrant organic matter, which may both occur at higher densities near larger trees. Our results indicate that plant-soil feedbacks change through tree ontogeny and provide evidence for a novel link between whole-system carbon fluxes and forest structure.
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Gaber, Brigitte A., and Thomas C. Hutchinson. "Chemical changes in simulated raindrops following contact with leaves of four boreal forest species." Canadian Journal of Botany 66, no. 12 (December 1, 1988): 2445–51. http://dx.doi.org/10.1139/b88-332.
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Simulated raindrops of pH 5.6 or 3.2 were sprayed on four boreal forest plant species in situ, and raindrops were subsequently collected from their leaves for chemical analysis. The purpose was to understand better the changes involved in foliar neutralisation of acidic raindrops. The species used were Cornus canadensis, Aralia nudicaulis, Maianthemum canadense, and Acer spicatum. Samples were analysed for Ca2+, Mg2+, Na+, K+, [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], Cl−, and F−, as well as pH. Changes in leaf raindrop ion concentrations were greater when sprayed with the pH 3.2 than with the pH 5.6 rain. Both increases and decreases in ion concentration were found, indicating leaching and (or) dissolution of particulates on the leaf or retention by the canopy, respectively. Rapid changes in ion concentrations suggest surface deposits play an important role in leaf raindrop neutralisation. Increases in [Ca2+] and [Mg2+] in raindrops with greater neutralisation are evidence that cation exchange may also be occurring (r2 = 0.170 and 0.321, respectively, at pH 3.2; p < 0.01). There were significant negative correlations between changes in [H+] and changes in[Formula: see text], [Formula: see text], and [Formula: see text] (r2 = 0.562, 0.525, and 0.297, respectively, at pH 3.2;p < 0.01). Most of the other ions measured also showed significant correlations with changes in [H+], but generally the correlation could account for only a small percentage of the observed results (low r2). Dry deposition was also measured.
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Deighton, Holly D., and Shaun A. Watmough. "Effects of Non-Industrial Wood Ash (NIWA) Applications on Soil Chemistry and Sugar Maple (Acer saccharum, Marsh.) Seedling Growth in an Acidic Sugar Bush in Central Ontario." Forests 11, no. 6 (June 19, 2020): 693. http://dx.doi.org/10.3390/f11060693.
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Research Highlights: In central Ontario, large quantities of non-industrial wood ash (NIWA) are generated and could be used as a forest soil amendment to counteract soil acidification and base cation depletion caused by decades of acid deposition. Background and Objectives: The properties and biogeochemical responses of NIWA have not been thoroughly explored, and field experiments must be conducted before NIWA can be regulated as a forest soil amendment in Ontario. Materials and Methods: In this study, soil chemistry and sugar maple (Acer saccharum, Marsh.) seedling growth and chemistry were measured in an acidic sugar bush over twelve months following a NIWA field experiment. Plots (2 m by 2 m) were established with sugar maple, white pine (Pinus strobus L.), and yellow birch (Betula alleghaniensis Britt.) NIWA treatments applied at rates of 6 Mg ha−1 along with untreated control plots. Results: Ash chemistry varied significantly among species and yellow birch ash generally had much higher metal concentrations compared with other species. Following ash application, significant increases in soil pH and calcium and magnesium concentrations were observed, however the level of response varied by treatment. Foliar concentrations of base cations in sugar maple seedlings significantly increased in ash treatments and there was no significant treatment effect on foliar metal concentrations or seedling growth. In roots and shoots, concentrations of several metals (manganese, aluminum, iron, boron, arsenic, cadmium, zinc, copper, lead, chromium, and nickel) increased after ash application, however response was most pronounced in yellow birch ash. Conclusions: These results suggest that application of NIWA can counteract the lasting effects of acid rain by increasing soil pH and base cation concentrations, as well as increasing sugar maple seedling foliar nutrient concentrations, but ashes from species with high metal contents may also increase metal availability to vegetation, at least in the short-term.
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Hall, G. "Peronospora ficariae. [Descriptions of Fungi and Bacteria]." IMI Descriptions of Fungi and Bacteria, no. 120 (August 1, 1994). http://dx.doi.org/10.1079/dfb/20056401195.
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Abstract A description is provided for Peronospora ficariae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Anemone coronaria, Helleborus purpurascens, Ficaria calthifolia, F. ledebourii, F. ficarioides, Ranunculus abortivus, R. acriformis, R. acer, R. acris, R. alpestris, R. auricomus, R. bulbosus, R. carpaticus, R. cassubicus, R. constantinopolitanus, R. crenatus, R. fascicularis, R. ficaria (= Ficaria verna), R. flammula subsp. flammula, R. languinosus, R. lateriflorus, R. lingua, R. montanus, R. nemorosus, R. oreophilus, R. oxyspermus, R. pedatus, R. pennsylvanicus, R. platanifolius, R. polyanthemus, R. pseudoplatanus, R. recurvatus, R. repens, R. sardous, R. scleratus, R. septentrionalis, R. uncinatus (= R. bongardi), R. velutinus. DISEASE: Downy mildew of Ranunculus species, covering the entire leaf undersurface. GEOGRAPHICAL DISTRIBUTION: Asia-Temperate: China, Kazakhstan, Kirgizistan, Russia (Kamchatka), Stavropol, Japan. Australasia: New Zealand. Europe: Austria, Belgium, Belorussiya, Bulgaria, Czechoslovakia, Denmark, Eire, Estonia, Faeroes, Finland, France, Germany, Hungary, Iceland, Italy, Latvia, The Netherlands, Norway, Poland, Romania, Russia (Krym, Moscow, Pskov, Novgorod, St. Petersburg, Saratov, Smolensk, Tambov, Tatariya, Tula, Yaroslavl) Sweden, Switzerland, Ukraine, UK (England, Scotland, Wales, Channel Islands), Yugoslavia. North America; Canada (British Columbia, Que), USA (Alabama, Idaho, Maine, Michigan, Oregon, Wisconsin, Washington State, Wyoming, New York). South America: Argentina, Dominican Republic. TRANSMISSION: By conidia dispersed by wind or rain-splash. The role of oospores in disease transmission is unknown, although they may act as perennating structures.