Sugar Maple Seedlings Research Articles

Effect of soil K, Ca and Mg saturation and endomycorrhization on growth and nutrient uptake of sugar maple seedlings

Nutrient imbalances of declining sugar maple (Acer saccharum Marsh.) stands in southeastern Quebec have been associated with high exchangeable Mg levels in soils relative to soil K and Ca. A greenhouse experiment was set up to test the hypothesis that the equilibrium between soil exchangeable K, Ca, and Mg ions influences the growth and nutrient status of sugar maple seedlings. Also tested was whether endomycorrhization can alter nutrient acquisition under various soil exchangeable basic cations ratios. Treatments consisted of seven ratios of soil exchangeable K, Ca, and Mg making up a total base saturation of 58%, and a soil inoculation treatment with the endomycorrhizal fungus Glomus versiforme (control and inoculated), in a complete factorial design. Sugar maple seedlings were grown for 3 months in the treated soils. Plant shoot elongation rate, dry biomass and nutrient concentrations in foliage were influenced by the various ratios of soil cations. The predicted plant biomass and foliar K concentration were highest at a soil Ca saturation of 38%, a soil K saturation of 12%, and a soil Mg saturation of 8%. Potassium concentration in foliage was dependent on the level of Ca and Mg saturation in the soil when soil K saturation was close to 12%. Foliar Ca and Mg levels were more dependent on their corresponding levels in soil than foliar K. Colonization by G. versiforme did not influence seedling growth and macronutrient uptake. The results confirm that growth and nutrition of sugar maple are negatively affected by imbalances in exchangeable basic cations in soils.

Response of sugar maple to multiple year exposures to ozone and simulated acidic precipitation

Potted sugar maple seedlings were exposed to ozone and acidic precipitation in open-top chambers for three consecutive growing seasons. Periodic measurements of photosynthesis, dark respiration, through-fall and soil solution chemistry, and annual measurements of the weight of plant parts were made. Experimental treatments caused few and minor effects on above- or below-ground growth of the seedlings, even after three growing seasons. There were trends for reduced photosynthesis in trees exposed to elevated concentrations of ozone and increased photosynthesis in those exposed to the lowest pH simulated rain treatment. The chemistries of soil-solutions and through-fall were not altered significantly by treatment. Although major effects were not observed, sugar maple may respond to exposures that take place over a significant part of its life cycle.

UV-B-Mediated Changes on Below-Ground Communities Associated with the Roots of Acer saccharum

Little is known about how exposure to UV-B radiation affects rhizosphere microbes. Rhizosphere organisms are fed primarily by root-derived substrates and fulfil functions such as mineralization, immobilization, decomposition, pathogeneity and improvement of plant nutrition ; they form the base of the below-ground food web. In this study, we exposed Sugar Maple (Acer saccharum) seedlings to UV-B radiation in order to determine if UV-B influences the activities of mycorrhizal and non-mycorrhizal fungi, bacteria and microbe-feeding arthropods in the rhizosphere. Below-ground organisms are greatly affected by UV-B radiation. Overall, carbon-flow in the plant soil system was shifted from a mutualistic-closed, mycorrhizal-dominated system to an opportunist-open, saprobe/pathogen-dominated one.

Effects of simulated acid rain on the growth, nutrition, foliar pigments and photosynthetic rates of sugar maple and white spruce seedlings

Sugar maple (Acer saccharum Marsh.) and white spruce (Picea glauca (Moench) Voss) seedlings were exposed to simulated acid rain (SAR) of pH 3.2, 4.3 and 5.6 for two and one-half growing seasons. Ambient rain was excluded from the treatment plots by mobile rain exclusion canopies. Sugar maple seedlings treated with pH 3.2 SAR had significantly higher foliar concentrations of nitrogen, sulphur and manganese, compared to either the pH 4.3 or 5.6 treated seedlings. The pH 3.2 treated seedlings also tended to have greater growth and photosynthetic rates compared to the pH 4.3 and 5.6 treated seedlings. In contrast, the pH 3.2 treated white spruce seedlings tended to have decreased growth and lower foliar potassium concentrations relative to the pH 4.3 and 5.6 treated seedlings. Statistically there were no significant treatment differences in seedling height, seedling diameter, foliar pigments, or photosynthetic rates in either the sugar maple or white spruce seedlings.

Competition vs. Facilitation of Tree Seedling Growth and Survival in Early Successional Communities

Competition has been widely assumed to be one of the principal mechanisms underlying the resistance of shrub and herbaceous communities to invasion by trees. However, there are potential mechanisms by which low—growing species, particularly in physically stressful sites, could enhance growth or survival of tree seedlings (facilitation). The balance of inhibition and facilitation will determine the net effects of a community on tree seedling growth and survival. We conducted a large—scale field experiment to quantify the net effects of four major physiognomic types (shrub tickets, shrubby grass meadows, grass meadows, and herbaceous meadows) commonly found both in old fields and along utility rights—of—way on the growth and survival of three common tree species: sugar maple (Acer saccharum), red maple (Acer rubrum), and gray birch (Betula populifolia). The eight community types were distributed in 23 sites representative of the range of upland environments present in the Hudson Valley of New York. Growth of planted seedlings of all three tree species was uniformly slow in all of the community types and environments. In all cases, the net effect of intact vegetation was to inhibit the growth of the tree seedlings. The intensity of competition varied substantially among the 23 sites but was not consistently related either to community type or to the biomass of the intact community. Instead, variation in the intensity of competition was related to the underlying favorability of the site for the growth of a particular target tree species. On the physically unfavorable sites, tree seedlings grew slowly because of physical stress rather than competition with the intact vegetation. As site quality increased, the intensity of competition increased. Thus, competition and physical stress traded off along a site–quality gradient, with the result that tree seedling growth was uniformly slow. In contrast to the results for growth, there were cases in which the survival of these young tree seedlings was enhanced (facilitated) by the presence of intact vegetation. In particular, survival of the highly shade tolerant but drought intolerant sugar maple seedlings was facilitated by intact vegetation at many sites, especially for the 1988 cohort, which experienced a drought during its first growing season. Since we detected no consistent differences among communities in the intensity of competitive effects on seedling growth, the apparent differences among early successional communities in resistance to tree seedling establishment may be caused by variation in the duration of competition resulting from differences in height and canopy structure of the low—growing communities.

Frost tolerance and bud dormancy of container-grown yellow birch, red oak and sugar maple seedlings.

Container-grown seedlings of red oak (Quercus rubra L.), sugar maple (Acer saccharum Marsh.) and yellow birch (Betula alleghaniensis Britton) in their first year of growth were overwintered outdoors. Tolerance of roots and stems to freezing was compared from late summer to the following spring. Mitotic activity in the apical bud was related more closely to air temperature than to bud dormancy as defined by days to bud break. In all species, stem hardening was observed before days to bud break reached a maximum. Dormancy release (days to bud break equal to zero) of yellow birch coincided with loss of stem hardening in the spring. Roots hardened more slowly, had a lower frost tolerance than stems in fall and winter, and dehardened earlier than stems in the spring. There were differences in stem and root hardiness among the species, with yellow birch being the most tolerant, followed by sugar maple and red oak. Primarily because of root sensitivity to frost, winter was a critical period for all three species, but particularly for red oak.

Benomyl and acephate applications increase survival of sugar maple seedlings during their first growing season in northern Pennsylvania

A study was conducted to determine the contributions of pathogenic fungi and insects to the mortality of sugar maple (Acersaccharum Marsh.) seedlings during their first season of growth. Replicated plots were located in four northern Pennsylvania stands in which the anthracnose pathogen, Disculacampestris (Pass.) von Arx, and the pear thrips, Taeniothripsinconsequens (Uzel), were associated with sugar maple seedlings. Survival was quantified for new seedlings treated with water (control), the systemic fungicide benomyl, the systemic insecticide acephate, or both, during May through August 1990. Treatment affected mean survival (p < 0.001), which was approximately 2–3 times higher in plots treated with benomyl and acephate than in plots treated with water only. Treatment with the fungicide, insecticide, or both also generally increased the percentage of seedlings bearing leaves (p < 0.001), the number of leaves per seedling bearing leaves (p < 0.001), shoot weight (p = 0.015), and root weight (p = 0.018). Diseases caused by fungi and damage from insects may be the major factors affecting survival of new sugar maple seedlings.

Effect of ozone on the development of vesicular-arbuscular mycorrhizae in sugar maple saplings

We examined the effects of ozone on the incidence of vesicular-arbuscular mycorrhizae in the roots of sugar maple (Acer saccharum) seedlings using a modified grid-line intersect method. The presence of vesicles, arbuscules, hyphal coils and internal mycelium was recorded. As the concentration of ozone increased, the frequency of vesicles, hyphal coils and internal mycelium increased while that of arbuscules decreased. Total infection rates, however, remained unchanged with increasing ozone levels. It is suggested that the fungi are responding to stress in the plant by increasing the production of less energy demanding and less efficient organs for exchange of nutrients (coils), and by increasing the resources allocated to storage and future growth (vesicles). The increase in internal mycelium (most of which was probably not mycorrhizal) may represent an increase in susceptibility to infection by fungi other than vesicular-arbuscular mycorrhizal fungi.

Foliar Amino Acid Accumulation as an Indicator of Ecosystem Stress for First‐Year Sugar Maple Seedlings

AbstractAccumulation of certain plant foliar amino acids (arginine, glutamine, and proline) can be used as indicators of anthropogenic and natural stressors, such as atmospheric deposition and mineral nutritional imbalances, which result in decreased plant growth. In this study a number of factors were evaluated to assess the use of foliar amino acid accumulation as indicators of sugar maple seedling stress at two sugar maple dominated forests in Michigan. These factors were: (i) first‐year sugar maple (Acer saccharum Marshall) seedling growth, (ii) N and P nutrition, (iii) soluble foliar and root total amino acid concentrations, and (iv) concentrations of foliar arginine, glutamine, and proline. The most southern site (Wellston), which was exposed to high atmospheric deposition and had high available soil P and seedling foliar P, had greater seedling growth. Foliar glutamine, arginine, and proline were greater at the most northern site (Alberta), which received lesser amounts of atmospheric deposition, but also had lower levels of available soil phosphorus, seedling foliar phosphorus, less seedling growth, and greater canopy closure. These results suggest that since atmospheric deposition is high in nitrogen, even the low levels of deposition at Alberta may be interacting with ecological variables such as, available soil phosphorus, light, or moisture to result in N/P imbalances and consequently higher arginine and glutamine concentrations in seedling foliage.

Development of vesicular–arbuscular mycorrhizae in sugar maple (Acer saccharum) and effects of base-cation ammendment on vesicle and arbuscule formation

The development, condition, and incidence of vesicular–arbuscular mycorrhizae of Acer saccharum (sugar maple) seedlings grown in the greenhouse in natural sugar maple forest soil substrate were examined. The effects of the addition of a cation mixture containing calcium, magnesium, and potassium were also studied. The mycorrhizal structures observed were similar to those found in natural field conditions. Mycorrhizae developed intracellularly via hyphal coils, and arbuscules usually developed from these coils, forming arbusculate coils. This development is different from that observed in most annual crop plants. Vesicular–arbuscular mycorrhizal structures appeared within 30 days. The rate of mycorrhizal infection decreased, along with plant health, as the quantity of the added cations was increased, but the amendment did not affect the morphology of the infection. More vesicles were observed in the lowest level of application than in controls, suggesting a stress response and possible relationship between plant health and condition of the mycorrhizal association. Key words: Acer saccharum, development, vesicular–arbuscular mycorrhizae.

Light environment alters response to ozone stress in seedlings of Acer saccharum Marsh, and hybrid Populus L.: II. Diagnostic gas exchange and leaf chemistry.

Diagnostic gas exchange measurements and foliar chemical assays were conducted on hybrid poplar (Populus tristis Fisch. ×P. balsamifera L. cv. Tristis) and sugar maple (Acer saccharum Marsh.) seedlings grown under contrasting light and ozone treatments. Seedlings were grown in low irradiance (c. 2.5 mol m-2 d-1 ) and six-fold greater irradiance (c. 16.6 mol m-2 d-1 ) in combination with low (< 10 nl I -l ) and elevated (99-115 nl 1-1 ) ozone. Analysis of light response curves showed ozone-induced reductions in photosynthetic capacity and quantum yield for unshaded poplar and shaded sugar maple, but not the contrasting light treatments. Photosynthesis at saturating CO2 concentrations was decreased in the elevated ozone treatment in both the unshaded and shaded poplar and in shaded sugar maple. Poplar had significant reductions in chlorophyll concentration due to ozone exposure in both unshaded and shaded treatments. Older leaves of unshaded poplar plants had significantly greater reductions in chlorophyll levels due to ozone than older leaves of shaded plants. In maple, only shade-grown leaves had significant decreases in chlorophyll concentration due to ozone exposure. The diagnostic gas exchange measurements in conjunction with chlorophyll measurements indicate that in hybrid poplar, unshaded leaves may be more sensitive to ozone than shade leaves, while in sugar maple, shade leaves are more sensitive to ozone. For hybrid poplar a decrease in photosynthetic capacity, quantum yield and chlorophyll concentration in the unshaded, moderately high light environment due to elevated ozone is consistent with prior studies. The results indicating that sugar maple seedlings may be more detrimentally affected by elevated ozone in the lower light environment may have serious implications for this and other shade-adapted species with respect to their performance in an understorey environment.

Symptoms, Association, and Pathogenicity ofDiscula campestris,a Cause of Sugar Maple Seedling Anthracnose

Mortality of sugar maple (Acer saccharum) seedlings during their first season of growth occurred in 1989 and 1990 in northern Pennsylvania stands infested with pear thrips (Taeniothrips inconsequens). Leaves became spotted and wafer-soaked, then collapsed or dropped, and upper portions of stems became necrotic. Ten samples, each consisting of five symptomatic seedlings, were collected in June from each of five stands (one in 1989, four in 1990) and incubated 2-4 days in moist chambers. Acervular conidiomata and conidia of a fungus identified as Discula campestris were observed on leaves of 247 of 250 seedlings. The fungus was isolated from one seedling of each sample (50 of 50 attempts)

Effect of site characteristics and 1st- and 2nd-year seedling densities on forest development in a northern hardwood forest

Factors influencing the initial colonization and subsequent (18-year) survivorship of trees were studied in two clear-cut watersheds in the Hubbard Brook Experimental Forest in New Hampshire. Variation in microsite conditions associated with the harvest operations (e.g., soil scarification, slash) and physical gradients within the watershed were particularly important in determining 1st- and 2nd-year densities of pin cherry (Prunuspensylvanica L.) and yellow birch (Betulaalleghaniensis Britt.), whereas factors relating to seed availability and the presence of advance seedlings and sprouts were important in determining 1st- and 2nd-year white ash (Fraxinusamericana L.) density. The 1st- and 2nd-year densities of sugar maple (Acersaccharum Marsh.) and beech (Fagusgrandifolia Ehrh.) were relatively independent of factors measured in this study and were probably related to both seed availability and the presence of advance seedlings and sprouts. Physical site factors immediately following clear-cutting continued to be important in determining the density of pin cherry and yellow birch at stand age 18 years, whereas 2nd-year sugar maple and beech seedling and sprout densities were the most important factors in determining the densities of these species 18 years following clear-cutting.

Soil nitrogen availability influences seasonal carbon allocation patterns in sugar maple (Acersaccharum)

The influence of soil N availability on growth, on seasonal C allocation patterns, and on sulfate-S content in sugar maple seedlings (Acersaccharum Marsh.) was tested experimentally. Relative to controls, the production of foliage doubled in response to high N availability, and the production of foliage, stems, coarse roots, and fine roots was halved in response to N deprivation. The period of foliage production was lengthened by fertilization and the period of fine root production was shortened by N deprivation compared with controls. In August, a shift in priority C allocation from foliage to roots occurred in the N-deprivation treatment. Therefore, during this month alone, the shoot to root ratio was greater in fertilized plants (1.0) than in N-deprived plants (0.5). Allocation to storage reserves was highest in N-deprived and lowest in fertilized plants (average 160 vs. 125 mg glucose/g biomass produced), and storage in roots of unfertilized plants commenced earlier (August) than in fertilized plants (after September). This resulted in unfertilized plants having higher fine root starch concentrations (5.2%) than fertilized plants (4.0%) in December, although sugar concentrations were similar (5.7%). The lengthened season of shoot growth and the low starch to sugar ratios in fine roots of fertilized plants are symptoms consistent with a higher risk of frost injury and microbial pathogen infection. Although soil N availability did not influence the sulfate-S content in foliage, N deprivation resulted in higher organic S to N ratios. This suggests that more S-containing proteins are produced when N availability is poor.

Water relations and gas exchange of Acer saccharum seedlings in contrasting natural light and water regimes.

Field measurements were made of leaf photosynthesis (A), stomatal conductance (g) and leaf water relations for sugar maple (Acer saccharum Marsh.) seedlings growing in a forest understory, small gap or large clearing habitat in southwestern Wisconsin, USA. Predawn water status, leaf gas exchange and plasticity in field and laboratory water relations characteristics were compared among contrasting light environments in a wet year (1987) and a dry year (1988) to evaluate possible interactions between light and water availability in these habitats. Leaf water potentials (Psi(leaf)) at predawn and midday were lower for clearing than gap or understory seedlings. Acclimation of tissue osmotic potentials to light environment was observed among habitats but did not occur within any of the habitats in response to prolonged drought. During a summer drought in 1988, decreases in daily maximum g (g(max)) and maximum A (A(max)) in clearing seedlings were correlated with predawn Psi(leaf), which reached a seasonal minimum of -2.0 MPa. Under well-watered conditions, diurnal fluctuations in Psi(leaf) of up to 2.0 MPa in clearing seedlings occurred along with large midday depressions of A and g. In a wet year, strong stomatal responses to leaf-to-air vapor pressure difference (VPD) in sunny habitats were observed over nine diurnal courses of gas exchange measurements on seedlings in a gap and a clearing. Increasing stomatal limitations to photosynthesis appeared to be responsible for the reduction in A at high VPD for clearing seedlings. In understory seedlings, however, low water-use efficiency and development of leaf water deficits in sunflecks was related to reduced stomatal limitations to photosynthesis relative to seedlings in sunny habitats. Predawn Psi(leaf) and VPD appear to be important factors limiting carbon assimilation in sugar maple seedlings in light-saturating irradiances, primarily through stomatal closure. The overall results are consistent with the idea that sugar maple seedlings exhibit "conservative" water use patterns and have low drought tolerance. Leaf water relations and patterns of water use should be considered in studies of acclimation and species photosynthetic performance in contrasting light environments.

Leaf Mass Per Area, Nitrogen Content and Photosynthetic Carbon Gain in Acer saccharum Seedlings in Contrasting Forest Light Environments

Total daily photosynthetic photon flux density (PPFD) varied by two orders of magnitude across forest understorey, gap and clearing habitats for sugar maple (Acer saccharum) seedlings in south-western Wisconsin, USA. Area-based photosynthetic capacity (A max /area) was greater in clearing or gap than in understorey seedlings, but little photosynthetic acclimation was observed between gap and clearing seedlings. We observed significant correlations between A max and leaf nitrogen content (N) among seedling populations from the three habitats when expressed on an area basis, but not on a mass basis because of scaling of leaf mass per unit area (LMA) with N (...)

Regeneration of Northern Hardwoods in the Northeast with the Shelterwood Method

Abstract Study plots (1/4 ac) were located in four northern hardwood stands in Vermont, and shelterwood canopy covers of 40, 60, 80, and 100%, and a control (no cutting) were established. Regeneration on small plots within the treated areas was sampled over a 3-year period and the composition of saplings determined after 6 years. While there were substantial increases in amount of regeneration under most canopy covers, there was no significant differences due to treatment. Some important trends, however, were evident. Sugar maple showed some increase in seedling density under most canopy densities with up to 68,000 new sugar maple seedlings per acre under 60% canopy cover. Yellow birch did best under 40 to 80% canopy cover and with good soil scarification. White ash increased under most densities but was best at about 80% canopy cover. Competitors, beech, striped maple, and hobblebush, increased under most densities. At about 60% canopy cover and less, raspberries and blackberries, pin cherry, and other shade-intolerant species increase in abundance. Among regeneration less than 3 ft all after 3 years, preferred species outnumbered less preferred species by 5 to 1. Among regeneration over 3 ft tall when examined 6 years after treatment, the less preferred species, on average, outnumber preferred species by 2 to 1 (sugar maple 0-3430/ac, yellow birch 0-1920/ac, beech 200-2220/ac and striped maple 0-3130/ac). Most beech regeneration seemed to arise as root suckers. Small striped maple grew rapidly and assumed dominance among the regeneration when released. Northern hardwoods have diverse composition in the overstory, and much of the regeneration tallied after 3 years was already in place when the shelterwood cuts were made. Advanced regeneration as well as new regeneration is the key to success, or failure, if it is predominantly undesirable species. In implementing a shelterwood in northern hardwoods, 60 to 80% canopy cover seems good for most species. All trees below the main canopy should be cut to create a high canopy shade. Undesirable species should be controlled by cutting or possibly herbicides before or when the stand is cut, with additional treatment as necessary to maintain desired composition. North. J. Appl. For. 8(3):99-104.

Growth patterns of sugar maple seedlings and mature trees in healthy and in declining hardwood stands

Openings created in the forest canopy as a result of the decline of sugar maple (Acersaccharum Marsh.) may increase microsite heterogeneity and favor the growth of tree seedlings on the forest floor and possibly neighboring healthy trees because of resource release. To corroborate these hypotheses, I studied the growth of sugar maple seedlings and mature trees, and some microsite characteristics, in healthy and in declining hardwood stands. Sampling was carried out in 400-m2 quadrats in four stands of similar composition. In two of the stands, the trees showed no apparent symptoms of decline (healthy stands), but in the other two (declining stands), dieback had caused tree cover to be reduced by ≈25 to 30%. Photosynthetically active radiation below the canopy was significantly lower and less variable in the healthy than in the declining stands, under both cloudy and sunny conditions. In one of the declining stands, soil pH was higher and soil organic matter content was lower than in both healthy stands. Stem elongation of sugar maple seedlings did not differ among the stands prior to 1984, but following that date it was significantly higher and more variable among seedlings in the declining stands. Ring width of apparently healthy trees decreased markedly in the early 1980s and increased somewhat during the 1985–1987 period on the declining sites. Microsite heterogeneity and growth of tree seedlings on the forest floor were thus greater in the declining than in the healthy stands. Neighboring healthy trees did not necessarily respond to the opening of the canopy (as a result of dieback) by increased ring width; this possibly resulted from the hierarchical position within the canopy, the differential time of reaction, and the age and (or) the health status of each individual.

Survival of Bacillus subtilis in Silver and Sugar Maple Seedlings over a Two-Year Period

One-year-old seedlings of Acer saccharinum (silver maple) and A. saccharum (sugar maple) that were inoculated with a Rifampicin-resistant strain of B.s. were found to contain bacteria resembling B.s. after 12 and 24 mo. After 2 yr, the bacteria were recovered from the sylem tissue located 30-72 cm and 5-54 cm from the inoculated site in silver and sugar maple, respectively. Therefore, B.s., a potential antagonist to Verticillium dahliae, can survive and be transported into newly formed xylem tissue of silver and sugar maple trees

Effect of landfill leachate irrigation on red maple (acer rubrum L.) and sugar maple (acer saccharum marsh.) seedling growth and on foliar nutrient concentrations

Greenhouse experiments were conducted to investigate the nature and severity of stresses imposed on northern hardwood tree species (red maple (Acer rubrum L.) and sugar maple (Acer saccharum Marsh.)) by the application of municipal landfill leachate. Red maple seedlings received applications of untreated and pretreated (lime, activated carbon) leachate, to both leaves and soil, at irrigation rates consistent with evapotranspirational demands. Plant height measurements indicated no significant growth effects arising from leachate application over a 7-week period. Stem diameter, however, was positively affected by applications of both untreated and lime-treated leachate diluted to 75% with deionized water. Iron foliar concentrations were significantly higher in seedlings irrigated with untreated leachate applied to leaves and soil, but not in seedlings where leachate was applied to soil only. Nitrogen foliar concentrations were substantially higher in seedlings receiving undiluted and untreated leachate applied to the soil only. The Cu concentration of the red maple foliage decreased appreciably in plants receiving moderate applications of leachate. Foliar Ca concentrations decreased notably in seedlings irrigated with untreated leachate applied to the soil and with diluted, carbon-treated leachate. The Cu concentration of the red maple foliage decreased appreciably in plants receiving applications of undiluted and 50% water-diluted lime-treated leachate while Mn levels were consistently high across all treatments. Leachate application did not cause any discernable changes in foliar concentrations of P, K, Mg, B or Zn. In an ancillary experiment, sugar maple seedlings were subjected to saturation/ drainage treatment cycles with undiluted and untreated leachate. Severe visible symptoms of vegetative stress were apparent within 24 h and 100% seedling mortality occurred after five such waterlogging cycles. Fe assimilation was apparent in both leachate treatments relative to the 24 h water treatment. Despite the short-term nature of the experiments, the results indicate how quickly forest vegetation may respond to altered chemical environments. This underscores the need for correct installation and control of leachate irrigation systems.