Larger Total Leaf Area Research Articles

Evaluation of Particulate Matter Deposition Efficiency and Air Quality Improvement by Vertical Shrub and Climber Walls

Fine particulate matter poses a significant health risk indoors, making indoor air quality improvement crucial. Vertical greenery systems offer a promising solution, but selecting suitable plant species remains a challenge. This study evaluated the PM deposition and air quality impact of six ornamental plants (climbers and shrubs) in a controlled chamber. Almost all plants reduced CO2 by 20%, while PM deposition varied by species, with Petunia hybrid being the most efficient. Total leaf area showed the strong correlated with PM deposition. These findings confirm the potential of ornamental plants, particularly those with large total leaf area, for PM reduction in vertical greenery systems. Further research with a wider range of plants and advanced characterization techniques is needed to refine our understanding and develop practical guidelines for their effective use in indoor air purification.

Biomass allocation and plant morphology explain the difference in shrub species abundance in a temperate forest.

In forested ecosystems, shrubs must succeed in persisting in low-light environments, while simultaneously having the ability to rapidly expand and occupy newly created canopy openings, yet little is known about the traits that make this possible. We hypothesize that shrub species that are abundant in the understory exhibit a specific set of functional traits that define their ability to persist during unfavorable periods and to rapidly exploit newly created habitats. We tested this by comparing field-measured functional traits such as biomass allocation, leaf display, crown morphology, and leaf traits, across individual size classes and two gap-forest environments of five shrub species. We observed significant differences in traits between species, size classes, and gap-forest environments. These differences were primarily related to biomass allocation traits, followed by leaf display, crown morphology, and leaf traits. Abundant shrubs like mountain maple (Acer spicatum) and hazelnut (Corylus cornuta) invested significantly more biomass in roots, had a larger total leaf area, and displayed leaves in a more efficient manner to intercept light. The high investment in root biomass can be interpreted as shrubs exploiting the persistence and colonization strategy through resprouting. Permanent sub-canopy status likely explains the importance of efficient leaf display, wherein abundant shrubs had a large leaf area with minimal support structures.

Comparison of the Particulate Matter Removal Capacity of 11 Herbaceous Landscape Plants

Background and objective Particulate matter (PM) has a fatal effect on health. There have been many studies on the use of plants such as trees and shrubs as eco-friendly and sustainable biofilter for the removal of PM. In forming more green space, ground cover plants play an important role in multi-layered planting. This study was conducted to investigate the ability of plants to reduce PM, targeting Korean native ground cover plants with high availability in urban green spaces. Methods For 4 species of Asteraceae, 4 species of Liliaceae, and 3 species of Rosaceae, one species of plants at a time were placed in an acrylic chamber (800 × 800 × 1000 mm, L × W × H) modeling an indoor space. After the injection of PM, the amount of PM remaining in the chamber over time was investigated. Results For all three types of PM (PM10, PM2.5, PM1), significant difference occurred in the amount of PM remaining between plant species after 1 hour in the Liliaceae chamber, 3 hours in the Asteraceae chamber, and 5 hours in the Rosaceae chamber. With Liliaceae, the leaf area and the amount of PM remaining in the chamber showed a negative (−) correlation. With the Asteraceae and Rosaceae, there was a weak negative correlation between the leaf area and the amount of PM remaining in the chamber. Conclusion When using ground cover plants as a biofilter to remove PM, it is considered effective to select a species with a large total leaf area, especially for Liliaceae.

High doses of ethylenediurea (EDU) as soil drenches did not increase leaf N content or cause phytotoxicity in willow grown in fertile soil

Ground-level ozone (O3) levels are nowadays elevated in wide regions of the Earth, causing significant effects on plants that finally lead to suppressed productivity and yield losses. Ethylenediurea (EDU) is a chemical compound which is widely used in research projects as phytoprotectant against O3 injury. The EDU mode of action remains still unclear, while there are indications that EDU may contribute to plants with nitrogen (N) when the soil is poor in N and the plants have relatively small leaf area. To reveal whether the N content of EDU acts as a fertilizer to plants when the soil is not poor in N and the plants have relatively large total plant leaf area, willow plants (Salix sachalinensis Fr. Schm) were exposed to low ambient O3 levels and treated ten times (9-day interval) with 200mL soil drench containing 0, 800 or 1600mg EDU L−1. Fertilizer was added to a nutrient-poor soil, and the plants had an average plant leaf area of 9.1m2 at the beginning of EDU treatments. Indications for EDU-induced hormesis in maximum electron transport rate (Jmax) and ratio of intercellular to ambient CO2 concentration (Ci:Ca) were observed at the end of the experiment. No other EDU-induced effects on leaf greenness and N content, maximum quantum yield of photosystem II (Fv/Fm), gas exchange, growth and matter production suggest that EDU did not act as N fertilizer and did not cause toxicity under these experimental conditions.

Effects of soil nutrient conditions on water transport properties and recovery from severe drought stress in Pinus densiflora saplings

ABSTRACTTo evaluate the acclimation of water transport properties to soil nutrient conditions, morphological and hydraulic traits were measured in 4-year-old potted saplings of Japanese red pine that were grown under differing nutrient conditions for 3 years. To compare recovery from severe drought stress under differing nutrient conditions, the well-watered saplings were subjected to drought treatments of almost Ψ50 by stopping irrigation; this is equivalent to the xylem water potential at which 50% loss of hydraulic conductivity occurs. After resuming daily watering, the xylem water potential and gas exchange rate were measured. Whole-plant transpirational demand from large total-leaf area tended to be high for plants under high-nutrient conditions. However, no differences were observed in water transport properties, such as the conducting area, hydraulic efficiency, and cavitation resistance, suggesting that acclimation of the hydraulic architecture did not occur when plants were grown under sufficient soil moisture conditions. The root dry weight tended to be large and the belowground dry mass to root dry mass (T/R ratio) tended to be low for plants under high-nutrient conditions. Plants grown under high-nutrient conditions recovered their gas exchange rate and leaf-specific hydraulic conductance slightly during the month following severe drought stress by irrigation. The recovery of Japanese red pine appears to vary under different levels of nutrient availability probably because of the influence of root water absorption capacity.

Low vapour pressure deficit affects nitrogen nutrition and foliar metabolites in silver birch.

Air humidity indicated as vapour pressure deficit (VPD) is directly related to transpiration and stomatal function of plants. We studied the effects of VPD and nitrogen (N) supply on leaf metabolites, plant growth, and mineral nutrition with young micropropagated silver birches (Betula pendula Roth.) in a growth chamber experiment. Plants that were grown under low VPD for 26 d had higher biomass, larger stem diameter, more leaves, fewer fallen leaves, and larger total leaf area than plants that were grown under high VPD. Initially, low VPD increased height growth rate and stomatal conductance; however, the effect was transient and the differences between low and high VPD plants became smaller with time. Metabolic adjustment to low VPD reflected N deficiency. The concentrations of N, iron, chlorophyll, amino acids, and soluble carbohydrates were lower and the levels of starch, quercetin glycosides, and raffinose were higher in the leaves that had developed under low VPD compared with high VPD. Additional N supply did not fully overcome the negative effect of low VPD on nutrient status but it diminished the effects of low VPD on leaf metabolism. Thus, with high N supply, the glutamine to glutamate ratio and starch production under low VPD became comparable with the levels under high VPD. The present study demonstrates that low VPD affects carbon and nutrient homeostasis and modifies N allocation of plants.

Long-term effects of zero pruning on Grenache vines under drought conditions

Under drought conditions the influence of zero pruning (ZP) and hand pruning (HP) on yield, total soluble solids (degrees Brix), sugar production, dry matter production and total leaf area development of Grenache vines ( Vitis vinifera L.) was assessed from 1988 to 1996. ZP was superior to HP for yield, sugar production and dry matter production. Total soluble solids were occasionally reduced by ZP. These effects of ZP can be explained by the larger total leaf area. These results are specifically important with regard to low-yield viticulture with a severely limited total leaf area.

Leaf nitrogen distribution in relation to crown architecture in the tall canopy species, Fagus crenata.

The theory of optimal leaf N distribution predicts that the C gain of plants is maximized when the N content per unit area (N(area)) scales with light availability, but most previous studies have demonstrated that the N distribution is not proportional to light availability. In tall trees, the leaves are often clustered on twigs (leaf cluster) and not evenly distributed within the crowns. Thus, we hypothesized that the suboptimal N distribution is partly caused by the limited capacity to translocate N between leaf clusters, and consequently, the relationship between light and N(area) differs for leaves in different clusters. We investigated the light availability and N content of all individual leaves within several leaf clusters on tall trees of a deciduous canopy species Fagus crenata in Japan. We observed that the within-cluster leaf N distribution patterns differed from the between-cluster patterns and the slopes of the relationships between light and N(area) were lower within clusters than between clusters. According to the detailed analysis of the N distribution within leaf clusters, N(area) was greater for current-year shoots with greater light availability or a larger total leaf area. The latter pattern was probably caused by the greater sink strength of the current-year shoots with a larger leaf area. These N distribution patterns suggest that leaf clusters are fairly independent with respect to their N use, and the productivity of real F. crenata crowns may be less than optimal.

Post-silking accumulation and partitioning of dry matter, nitrogen, phosphorus and potassium in maize varieties differing in leaf longevity

Maize grains are formed after silking, but not all dry matter (DM), nitrogen (N), phosphorus (P) and potassium (K) deposited in grains are accumulated during grain filling. There is a conflict between sustaining post-silking photosynthesis and the remobilization and recycling of N, P and K from leaves to grain. To study the accumulation and partitioning patterns of DM, N, P and K after silking in maize with different leaf longevity, two field experiments with six maize varieties including early-senescing (old varieties) and stay-green leaves (new varieties) were conducted in successive years. The results demonstrated that new varieties had larger total leaf area and longer green leaf duration, and took up more N, P and K after silking than old varieties. Post-silking leaf appeared to provide sufficient assimilates for grain formation, while large amounts of N, P and K accumulated pre-silking were remobilized and exported from vegetative tissues, especially from leaves, in all varieties during grain filling. Post-silking leaf N export caused a large decrease in leaf N concentration in all maize varieties. Post-silking uptake of N and P account for 11–43% and 16–55% to total content of whole plants at maturity, but a post-silking loss of K from maize plants was observed, especially in old varieties. The export of N, P and K from leaves was similar in all varieties and an un-synchronized accumulation and partitioning of N, P and K during plant development was observed.

Effects of grasses on sapling establishment and the role of transplanted saplings on the light environment of pastures: implications for tropical forest restoration

AbstractQuestionDoes the presence of grasses affect the establishment (survival and growth) of tree saplings in an abandoned tropical pasture, and what is the potential of established saplings to modify pasture microenvironmental conditions, particularly light incidence?LocationAbandoned cattle pasture, in the humid tropics of SE Mexico (18°25′–18°45′ N, 95°00′–95°18′ W).MethodsThe establishment of four native fast‐growing tree species in a tropical abandoned pasture was evaluated. Saplings of Cecropia obtusifolia, Hampea nutricia, Omphalea oleifera and Erythrina folkersii were transplanted using a split‐plot design. Plant survival and growth were evaluated over 12 mo under two experimental treatments: presence and absence of grasses. Light incidence at ground level was used to evaluate microclimate conditions under the grass matrix, compared to light incidence under saplings established in the pasture.ResultsSaplings had high survival (49–88%) regardless of the presence of grasses. In the presence of grasses, growth of surviving saplings either increased or was not impacted, and in only one out of eight comparisons did grasses negatively affect growth. The impact of saplings on light incidence in abandoned pastures depended on sapling species architecture: species with large total leaf area and canopy area ( H. nutricia and E. folkersii) significantly reduced light incidence (12–29% of total incidence), while narrow‐canopy species ( C. obtusifolia and O. oleifera) generated less intense shade (37–89% of total incidence).ConclusionsGrasses did not seem to represent a crucial limiting factor in sapling establishment of fast‐growing native species in the short term. In addition, shading by recruited saplings of some native species could be important to out‐compete grasses in the future, as well as for ‘facilitating’ regeneration of more shade‐tolerant species. Transplantation of fast‐growing native saplings into abandoned pastures, even without manipulation of the grasses, could be a useful practice for landscape‐scale restoration programmes in tropical areas. Evaluation of the longer‐term consequences (beyond the 1‐yr span of this study) warrants further research.

Genome-wide comparison of two poplar genotypes with different growth rates

The ecologically dominant and economically important genus Populus, with its available full genome sequence, has become an ideal woody species for genomic study. Rapid growth is one of the primary advantageous features of Populus, and extensive physiological research has been carried out on the growth of Populus throughout the growing period among different clones. However, the molecular information related to the mechanisms of rapid growth is rather limited. In this study, an Affymetrix poplar genome array was employed to analyze the transcriptomic changes from the pre-growth to the fast-growth phase in two poplar clones (P.deltoides×P.nigra, DN2, and P.nigra×(P.deltoides×P. nigra), NE19) with different growth rates. A total of 1,695 differently expressed genes were identified between two time points in NE19 and DN2 (two-way ANOVA, P<0.01 and fold change ≥2). Except for genes changing in common for both clones, many transcripts were regulated specifically in one genotype. After functional analysis of the differentially expressed genes, distinct biological strategies seemed to be utilized by the two genotypes to accommodate their fast-growth phase. The faster-growing clone NE19, which has a higher photosynthetic rate and larger total leaf area, emphasized growth-related primary metabolism. However, the slower-growing DN2 tended to have more up-regulated genes involved in defense-related secondary metabolism and stress response. Emphasis of such divergent biological processes in two clones may explain their significant growth differences during the fast-growth phase.

Growth and physiological state of beech seedlings grown in a nursery in different light conditions

Seedlings of European beech of two populations (from the 4&lt;sup&gt;th&lt;/sup&gt; and 7&lt;sup&gt;th&lt;/sup&gt; forest altitudinal zone) were grown in a shaded and unshaded plastic greenhouse. The objective was to compare seedling growth and the function of assimilatory organs and to determine their reactions after transfer to different light conditions.Seedlings grown in the unshaded plastic greenhouse (the sun variant) were taller and stronger at the end of the first growing season and had the higher weight and volume of shoots and root systems than seedlings grown in the shade. A higher number of leaves, larger total leaf area and higher dry matter of leaves per 1 plant were determined in seedlings grown in the sun. The average area of one leaf was larger in seedlings grown in the shade. The higher photosynthetic electron transport rate (ETR) determined from the light curves of chlorophyll fluorescence in seedlings grown in the sun was apparently connected with the higher photosynthetic rate and more intensive growth of these seedlings. The transfer of seedlings from full sun to shade resulted only in small changes in chlorophyll fluorescence (Fv/Fm, ETR). On the contrary, the transfer of seedlings from the shaded plastic greenhouse to the sun induced photoinhibition leading to a significant reduction in the maximum quantum yield of photochemistry Fv/Fm and in the photosynthetic electron transport rate (ETR).

Growth properties of 16 non‐pioneer rain forest tree species differing in sapling architecture

Summary 1. Sapling architecture may be an important determinant of performance traits, such as light interception and height growth, but few studies have examined the direct relationship between sapling architecture and growth properties. To study this relationship and the potential for strategic diversification, we analysed the growth properties in saplings of 16 Bornean tree species that differ in architecture. 2. Annual net production significantly differed amongst species and was positively correlated with total above‐ground dry mass, total leaf area and crown area. In contrast, the net assimilation rate was weakly but negatively correlated with these architectural traits. The net assimilation rate was virtually independent of leaf size and specific leaf area. Relationships between sapling architecture and relative growth rate in mass were weak. 3. The relative growth rate in height did not significantly differ amongst species, although their total dry mass, a proxy for extension cost, varied fourfold across species for a given sapling height. This is because the proportional increase in net production with total dry mass, which is based on a larger total leaf area and larger crown area, cancelled out the higher extension cost. All architectural traits, including leaf size and specific leaf area, failed to predict height growth rate. 4. Synthesis. Relative growth rates in both mass and height were relatively independent of sapling architecture. Of the architectural traits, leaf size, specific leaf area and stem diameter were poor predictors of growth properties, even though they were considered functionally important. These results clearly reject the classic hypothesis that architectural variation leads to a trade‐off between height growth and light interception, at least for the species that are under shaded conditions. However, functional variation ranging from species with high net production and low net assimilation rates (in saplings of equal height) to species with the opposite traits, which was accompanied by architectural variation in total dry mass and related size factors, may be important for the coexistence of these tree species. The possibility that small total dry mass may be advantageous in height growth under well‐lit conditions should be examined in future studies.

Comparison of the physiology, morphology, and leaf demography of tropical saplings with different crown shapes

Branch architecture, leaf photosynthetic traits, and leaf demography were investigated in saplings of two woody species, Homolanthus caloneurus and Macaranga rostulata, co-occurring in the understory of a tropical mountain forest. M. rostulata saplings have cylindrical crowns, whereas H. caloneurus saplings have flat crowns. Saplings of the two species were found not to differ in area-based photosynthetic traits and in average light conditions in the understory of the studied site, but they do differ in internode length, leaf emergence rate, leaf lifespan, and total leaf area. Displayed leaf area of H. caloneurus saplings, which have the more rapid leaf emergence, was smaller than that of M. rostulata saplings, which have a longer leaf lifespan and larger total leaf area, although M. rostulata saplings showed a higher degree of leaf overlap. Short leaf lifespan and consequent small total leaf area would be linked to leaf overlap avoidance in the densely packed flat H. caloneurus crown. In contrast, M. rostulata saplings maintained a large total leaf area by producing leaves with a long leaf lifespan. In these understory saplings with a different crown architecture, we observed two contrasting adaptation strategies to shade which are achieved by adjusting a suite of morphological and leaf demographic characters. Each understory species has a suite of morphological traits and leaf demography specific to its architecture, thus attaining leaf overlap avoidance or large total leaf area.

Population divergence in the plasticity of the response of Quercus coccifera to the light environment

Summary Quercus coccifera, a slow‐growing, evergreen oak, grows in contrasting environments in the Mediterranean Basin. Habitat‐based selection may have promoted divergence between populations with respect to phenotypic plasticity and genetic variability. We tested the hypothesis that populations of the Q. coccifera originating from a rock outcrop, a continental garrigue formation and an oceanic forest would differ in their plastic response to light intensity. Plants from these populations were grown from acorns in a common garden at 100% and 20% full sunlight. Light response analysis was based on photochemical efficiency, xanthophyll pool, nutrient allocation, growth, crown architecture and light absorption. Light‐responsive characters ranged from the subcellular to the whole‐plant level. The greatest divergences between sun and shade phenotypes were observed in leaf size, leaf angle and leaf area ratio. However, plasticity in these traits depended on plant provenance. Regardless of the level of organization, populations were invariably ranked in the same order of plasticity when averaged over light‐responsive features, with plants originating from the rock outcrop showing the least plasticity and those from the forest the largest. The forest population also had the greatest genetic variability with respect to the isoperoxidase polymorphism. Among populations, plants originating from the phosphorus‐deficient rock outcrop contained 30% more P per unit dry weight. Plants from the forest population had 5% more photoprotective xanthophylls, 30% larger total leaf area, with less lobed and larger leaves and a differential plasticity in leaf azimuth. Differences among populations suggested ecotypic differentiation towards less phenotypic plasticity in the most homogeneous light environments. The ecological breadth of the species seemed to be derived not only from its tolerance of Mediterranean conditions but also from the specialization of its populations in contrasting habitats.

Relationships between growth, specific leaf area and water use in six populations of Eucalyptus microtheca seedlings from two climates grown in controlled conditions

Summary To gain a better understanding of those parameters that control growth and productivity of Eucalyptus microtheca populations from seasonally dry to semi-arid sites in Australia we measured their total plant biomass, allocation of dry matter to roots and shoots, specific leaf area (SLA) and water use. For this purpose the seedlings were raised up to five months under three different pot moisture conditions applied by cyclical watering regimes. Young seedlings of six provenances of Eucalyptus microtheca fell generally into two groups, the Rockhampton, Walgett and Maree provenances which evolved in evenly distributed, though erratic, rainfall conditions at semi-arid sites, and the Pilbara, West Kimberleys and Camooweal provenances which evolved in seasonally dry sites with a reliable monsoon. The former group had the greater leaf area and total plant biomass. Specific leaf area correlated positively with leaf area and total plant biomass at various times across the experimental period. However, as only minor differences in the average plant water use and carbon discrimination were detected among the populations, greater biomass production in semi-arid populations appears to stem from their capacity to produce a large total leaf area with thin leaves, which thus contributes to the total plant photosynthesis. The root: shoot ratio was consistently higher in seedlings from seasonally dry sites compared to those from semi-arid sites. A higher ratio in seasonally dry sites is likely to be beneficial as it allows an adequate water supply for longer during the dry period. A greater allocation to roots apparently reduces the amount of leaf area produced, decreasing growth potential.

167 Nutrient Uptake and Growth Performance of OH87 and OH97 Pear Rootstocks

One-year-old (Old Home) OH87 and OH97 pear rootstocks were grown in 2-gallon containers under natural conditions at Corvallis, Ore., in in 1999. Uniform plants were harvested during August and September, and total leaf area, new shoot number and length, and root growth were measured. The kinetics of NH4+ and NO3- uptake by new roots of both rootstocks were determined with the ion-depletion technique. OH87 had larger total leaf area, and more and longer shoots than OH97. Total root biomass was similiar between the two rootstocks, but OH87 had a larger proportion of new roots and more extension roots than OH97. Both rootstocks had lower Km values for NH4+ absorption than for NO3- and therefore both had greater absorptive power for NH4+ than for NO3- at the low nutrient concentrations. The maximum uptake rates (Vmax) of OH97 were similiar for both NH4+ and NO3- absorption, but OH87 had a much higher maximum uptake rate for NO3- than for NH4+.

Field Performance of In wiro-propagated and Sucker-derived Plants of Banana (Musa spp.)

SummaryThe field performance of in vitro-propagated banana (Musa spp.) plants was compared with that of the sucker-derived plants. In vitro-propagated plants established and grew faster, taller and bigger than the conventional sucker-derived plants. The former produced more leaves resulting in a larger total leaf area (8001.5 cm2 per plant) than the latter (6613.1 cm2 per plant) and could be harvested earlier. The former also produced heavier bunches and fruit (15.2 kg for bunch and 200 g per finger of fruit) than the latter (9.0 kg for bunch and 136.4 g per finger of fruit). In this experiment, the in vitro-propagated plants had many intact roots and a bulk of vermiculite around their roots but the sucker-derived plants had many damaged roots at the time of planting. In addition, in vitro-propagated plants started growth earlier and grew faster enabling them to intercept more light for photosynthesis than the sucker-derived plants. This may explain the higher yield in the in vitro-propagated plants. We conclude that in vitro-propagated Shima banana performs better in terms of growth and yield than the sucker-derived plants under field conditions.

Effects of irrigation and nitrogen fertilization on the water relations ofPrunus aviumand ‘Colt’ (P. aviumL. xP. pseudocerasusLind.) in the nursery, and residual effects after outplanting

SummaryOne year old Prunus avium seedlings and hardwood cuttings of ‘Colt’ were lined out in a nursery and given supplementary nitrogen fertilizer and/or irrigation. Irrigation increased leaf conductance (gs) and leaf water potential (Ψ) in both genotypes but nitrogen did not affect these variables. In the following year, after outplanting, the residual effect of irrigation reduced gs compared with plants that had received no previous irrigation. Leaf conductance was greater and Ψ was lower in Prunus avium as compared with ‘Colt’ each year. The greater gs for P. avium led to greater water use per unit leaf area in this genotype. However, on a whole-plant basis, water use was approximately equivalent for each genotype due to a larger total leaf area on ‘Colt’. Water availability was the dominant factor in establishing early growth in these genotypes.

Seedling Growth and Morphology of the Deciduous Tree Cornus controversa in Simulated Forest Gap Light Environments in Subtropical China

Abstract Seedling growth and morphology of the deciduous tree Cornus controversa from subtropical China were studied in four simulated forest gap light environments: 100%, 55%, 33% and 18% full sunlight. The best performance was in 33% full sunlight. Overall, Cornus seedlings grew taller than those of five broad‐leaved evergreen species from the same area. In terms of total plant mass only Cinnamomum camphora seedlings grew bigger than Cornus seedlings. Cornus seedlings needed relatively small biomass investments to become tall and to produce a great total length of axes. Growth of Cornus seedlings was probably enhanced by their comparatively ‘cheap’ leaves in terms of weight per area, which resulted in large total leaf area per unit plant weight. The results provide ecophysiological support of Cornus' competitive strength in forest gaps amidst mostly evergreens.