Fast-growing Plant Research Articles

PHARMACOLOGICAL ATTRIBUTES OF BOMBAX CEIBA L.

The plant Bombax ceiba L. is a light demander, fast-growing plant. It is used in the treatment of many diseases. Our ancestors had a great knowledge of this plant and used to treat various ailments without having any side effects and the knowledge of the same has been transferred down to generations. The plant has stimulant, astringent, cooling, antiinflammatory,antimicrobial effect,etc.among many other health benefits.

OPTIMAL IN THE NATIONAL ENERGY SECTOR DIRECTIONS OF FORMATION OF INFRASTRUCTURE COMPLEX

OPTIMAL IN THE NATIONAL ENERGY SECTOR DIRECTIONS OF FORMATION OF INFRASTRUCTURE COMPLEX

Trachea features and fiber dimensions of fast-growing tree: A case study on wood samples from eastern Indonesia

Fast-growing plant is one of the characteristics of pioneer plants. Commonly, the plants grow in areas that is exposed to sunlight such as open area and forest edges. Fast-growing plants have different anatomical and physical wood characteristics compare with slow-growing plants. Therefore, this study aims to examine the anatomical characteristics of fast-growing plants, especially trees, namely the fiber cells and trachea features. A total of 33 wood samples from 28 species were used in this study. We used wood samples from Eastern Indonesia deposited at Herbarium Bogoriense. Examined wood samples are taken from branches with 1-2 cm of diameter. The anatomical characters observed were focused on two types of cells, namely fiber cells (fiber length, fiber diameter, fiber cell wall thickness, lumen width, identification of septate fibers and fibers pit) and the trachea (perforation type, pit arrangement, and pit form). From the observations of all wood samples showed that the length of fiber cells are classified as short (18 species) and medium (10 species) fiber. There are two groups of fiber cell wall thickness viz. very thin (16 species) and thin to thick (12 species). Septate fibers only found in 7 species especially Chisocheton and Teijsmanniodendron. Fiber’s pit observed in Horsfieldia parviflora, Mallotus peltatus, dan Neuburgia corynocarpa. All species have simple tracheal perforation with alternate or opposite pit arrangement. Moreover, branch wood samples have polygonal pit shape, oval or combination of those two shapes were found in some species, such as Horsfieldia parviflora, Sandoricum koetjape and Teijsmanniodendron bogoreinse.

Can the Biological Activity of Abandoned Soils Be Changed by the Growth of Paulownia elongata × Paulownia fortunei?—Preliminary Study on a Young Tree Plantation

Bioenergy crops play an ecologically and economically fundamental role as an alternative to agri-food productions and as renewable energy sources. Thus far, less attention has been given to assessing microbiological indicators of soil quality in bioenergy crops on abandoned land. The current study assessed microbial and biochemical properties of two soils with different textures in agroforestry plantations of Paulownia elongata × Paulownia fortunei, with regard to the analysis of potential for the reclamation and redevelopment of abandoned lands. The soil samples were characterised by measuring microbial biomass C and N, key enzyme activities, and determining the community-level physiological profiles (CLPP) using Biolog EcoPlates. Soil texture, sampling time (June and October), and distance of sampling (0.1 m and 1 m from a tree) had significant effects on microbiological properties. Moreover, dehydrogenases and acid phosphatase activities as well as microbial biomass C and N decreased with distance from the trees, and were significantly higher in the October than in the June. The community-level physiological profiles (CLPP) and diversity indices showed a similar trend to other parameters of biological activity. The results showed that there were significant differences in the AWCD (average well-colour development) of all carbon sources among the Paulownia microbial communities (p < 0.05). In summary, already after one year of tree planting, a statistically significant increase in microbial activity was found, regardless of soil texture, when evaluated by various methods. This proves the value of the Paulownia as fast-growing plant for recultivation and improvement of soil quality on abandoned land.

Growth and Nutritional Quality of Lemnaceae Viewed Comparatively in an Ecological and Evolutionary Context.

This review focuses on recently characterized traits of the aquatic floating plant Lemna with an emphasis on its capacity to combine rapid growth with the accumulation of high levels of the essential human micronutrient zeaxanthin due to an unusual pigment composition not seen in other fast-growing plants. In addition, Lemna’s response to elevated CO2 was evaluated in the context of the source–sink balance between plant sugar production and consumption. These and other traits of Lemnaceae are compared with those of other floating aquatic plants as well as terrestrial plants adapted to different environments. It was concluded that the unique features of aquatic plants reflect adaptations to the freshwater environment, including rapid growth, high productivity, and exceptionally strong accumulation of high-quality vegetative storage protein and human antioxidant micronutrients. It was further concluded that the insensitivity of growth rate to environmental conditions and plant source–sink imbalance may allow duckweeds to take advantage of elevated atmospheric CO2 levels via particularly strong stimulation of biomass production and only minor declines in the growth of new tissue. It is proposed that declines in nutritional quality under elevated CO2 (due to regulatory adjustments in photosynthetic metabolism) may be mitigated by plant–microbe interaction, for which duckweeds have a high propensity.

Production of esterified nanofibrillated cellulose from a lesser-known wood Species (Macaranga hypoleuca)

Macaranga hypoleuca, a lesser-known and rarely used wood species, is a pioneer species in the secondary succession that is classified as a fast-growing plant with long fibers. M. hypoleuca was composed of holocellulose, lignin, and extractives, at contents of 68.1 ± 0.5%, 25.5 ± 0.6%, and 4.7 ± 0.1%, respectively. In this study, refined M. hypoleuca pulp was treated by alkali treatment, delignification, and maleic acid hydrolysis. The pre-treated pulp was further disintegrated by mechanical treatment, which produced nanofibrillated cellulose (NFC) with a yield of 53.5 ± 2.7%. The average diameter of the NFC was 43.0 ± 4.9 nm. The use of maleic acid (C4H4O4) hydrolysis also reduced the hydrophilicity of the NFC, as confirmed by the Fourier-transform infrared (FTIR) spectra. It was determined that the Macaranga tree is a suitable lignocellulose source to produce NFC, which can be used in transparent flexible substrates, coating, and composite applications.

Nitrogenous Fertilizer Reduces Resistance but Enhances Tolerance to the Brown Planthopper in Fast-Growing, Moderately Resistant Rice.

Simple SummaryThe brown planthopper is a major rice pest in Asia that causes extensive damage where farmers apply large amounts of nitrogenous fertilizers. Over the last 50 years, host-plant resistance, i.e., a plant’s ability to deter planthoppers or reduce their survival and reproduction, has been the main focus of public research into planthopper management. However, there have been calls for increased attention to issues of rice tolerance against the planthopper, i.e., a plant’s ability to withstand attack and compensate for damage. We examined the interactions between planthoppers and 16 varieties of rice under varying levels of soil nitrogen. The varieties included susceptible, resistant and tolerant lines. We found that nitrogen generally increased planthopper fitness across the varieties; however, relative resistance was maintained in varieties with major resistance genes. Functional plant loss was found to be greatest in susceptible varieties after planthopper attack, and generally declined in resistant and tolerant varieties under increasing nitrogen levels. This increase in tolerance was most apparent among resistant and moderately resistant, large-sized, fast-growing varieties that were capable of overcoming relatively high weight and growth rate reductions.The brown planthopper, Nilaparvata lugens (Stål), is a key challenge to rice production in Asia. Outbreaks of planthoppers are associated with excessive fertilizer applications; consequently, we examined planthopper interactions with susceptible, tolerant and resistant varieties of rice under varying levels of soil nitrogen in a greenhouse experiment. We compared planthopper fitness (survival × reproduction) and plant tolerance (functional plant loss index) for 16 varieties at 0, 80 and 150 Kg added nitrogen ha−1. The planthoppers grew larger, developed more quickly and laid more eggs on susceptible varieties, compared with the resistant and tolerant varieties. Moreover, soil nitrogen generally increased planthopper fitness on resistant varieties, but relative resistance was maintained. Functional plant loss was highest among the susceptible varieties, but weight and growth rate reductions per mg of planthopper were often highest in the tolerant varieties. Tolerance was associated with large, fast-growing plants, with at least moderate resistance to the planthopper. Susceptibility was associated with a small size and/or an absence of resistance genes. Our results suggested that early-tillering rice plants can be both resistant and tolerant to the brown planthopper, but cannot be both susceptible and tolerant of planthoppers at high densities. This indicates that at least moderate resistance is required for tolerance against this herbivore. Furthermore, although dwarf varieties had a low tolerance of planthoppers, they could express resistance through functioning resistance genes.

How does a wetland plant respond to increasing temperature along a latitudinal gradient?

Global warming affects plant fitness through changes in functional traits and thereby ecosystem function. Wetlands are declining worldwide, and hence, ecosystem functions linked to wetlands are threatened. We use Caltha palustris “a common wetland plant” to study whether warming affects growth and reproduction differently depending on origin of source population, potentially affecting phenotypic response to local climate. We conducted a 2‐year in situ temperature manipulation experiment using clone pairs of C. palustris in four regions, along a 1300‐km latitudinal gradient of Sweden. Open‐top chambers were used to passively increase temperature, paired with controls. Growth and reproductive traits were measured from 320 plants (four regions × five sites × two treatments × eight plants) over two consecutive seasons to assess the effect of warming over time. We found that warming increased plant height, leaf area, number of leaves, and roots. High‐latitude populations responded more strongly to warming than low‐latitude populations, especially by increasing leaf area. Warming increased number of flowers in general, but only in the second year, while number of fruits increased in low‐latitude populations the first year. Prolonged warming leads to an increase in both number of leaves and flowers over time. While reproduction shows varying and regional responses to warming, impacts on plant growth, especially in high‐latitude populations, have more profound effects. Such effects could lead to changes in plant community composition with increased abundance of fast‐growing plants with larger leaves and more clones, affecting plant competition and ecological functions such as decomposition and nutrient retention. Effects of warming were highly context dependent; thus, we encourage further use of warming experiments to predict changes in growth, reproduction, and community composition across wetland types and climate gradients targeting different plant forms.

Silicon alleviates antimony phytotoxicity in giant reed (Arundo donax L.).

Silicon enhances photosynthetic efficiency, biomass, and lignification of root structures possibly limiting antimony translocation and mitigating phytotoxicity in giant reed plants. Antimony (Sb) is a non-essential metalloid causing toxic effects in plants. Silicon has been reported to impart tolerance against biotic and abiotic stress in plants. Fast-growing plant, giant reed (Arundo donax L.) is a promising energy crop, can be a suitable plant for phytoremediation. However, information regarding the tolerance capacity with respect to Sb toxicity and potential of Si to mitigate the Sb phytotoxicity in giant reed are very scarce. Rhizomes of giant reed were grown for ten weeks in hydroponics exposed to Sb, Si, and their combination wherein treatment without Sb/Si served as control. Effect of these treatments on rate of net photosynthesis and photosynthetic pigments, phytoextraction ability of Sb, Si and Sb uptake, plant biomass, and lignification and suberization of roots along with localization of Sb and Si were analysed. We found that Si considerably improved the growth and biomass of giant reed under Sb toxicity. Antimony reduced the photosynthesis and decreased the content of photosynthetic pigments, which was completely alleviated by Si. Silicon amendment to Sb treated plants enhanced root lignification. Silicon enhanced lignification of root structures probably restricted the Sb translocation. However, co-localization of Sb with Si has not been observed neither at the shoot nor at the root levels. Similarly, Sb was also not detected in leaf phytoliths. These findings suggest that Si treatment promotes overall plant growth by improving photosynthetic parameters and decreasing Sb translocation from root to shoot in giant reed by improving root lignification.

Potential of carbon stock on red jabon stand (Anthocephalus macrophyllus (Roxb.) Havil) in Tampinna Village, Angkona District, Luwu Timur Regency

In addition to producing wood as a raw material for construction, pulp and firewood, forests also serve as carbon sinks so they have an important role in the global carbon cycle. Red jabon is a fast-growing plant species, so it is suspected to have high carbon absorption. The purpose of this study is to know the potential of carbon content and increased uptake of carbon above the soil surface for species of red jabon (Anthocephalus macrophyllus (Roxb.) Havil) in the forest Tampinna village community. Methods of data collection in the field is done by census, that is data retrieval as a whole. In the sample tree, the diameter measured at breast height (dbh) and tree height (TBC). Furthermore, the resulting data was processed to determine the biomass produced by using allometric equations. Samples of 302 red jabon trees were obtained from six sites with four different age levels, which were three to six years old. Based on the result of paired observation test of red jabon biomass prediction by using volume formula gives bigger result than allometric equation. The average potential of total carbon uptake in red jabon stands is 19.57125 ton/ha. In general, there is a tendency that the older age of the tree stands to produce a large carbon content as well. Equation of relationship between age with carbon content in the form of quadratic.

EFFECT OF SEED TREATMENT VERSUS FIELD SPRAYING ON GROWTH AND YIELD PERFORMANCE OF MAIZE (Zea Mays)

This experiment examined the effect of seed treatment versus field spraying on the agronomic performance of three new maize varieties in Abeokuta. These maize varieties were 1) DMR-ESR-Y 2) SAMMAZ 15 and, 3) OBA SUPER 2. Treatments were 1) Control 2) Seed treatment with Dressforce (Active ingredient Imidacloprid) 3) Seedling spraying with Cypermethrin. The experiment was carried out during the early growing season between March and June, 2017 at the Teaching and Research Farm, Federal University of Agriculture, Abeokuta. The experiment was carried out on the field in a Randomized Complete Block Design with three replicates. Observations were recorded on Plant height, Number of leaves, Step girth, Leaf area, Percentage germination, Percentage tasselling, Number of cobs per plot, and 100- seed weight. Analysis of variance revealed that there were significant differences between the varieties except for Leaf area, Plant height, and the number of leaves and also there were significant differences among the treatment except for Percentage germination, Percentage tasselling, and Number of cobs per plot. Analysis of variance also revealed that there was no significant difference in the interaction between the varieties and treatment except for 100-seed weight. Mean separation among varieties revealed that DMR-ESR-Y had the best performance in terms of Percentage germination, Percentage tasselling, Number of cobs per plot, and 100-seed weight. SAMMAZ 15 had the best performance in the terms of leaf area, stem girth, plant height, and the number of leaves while OBA SUPER 2 had the lowest performance in all the parameters evaluated. The treated seed had the best performance in all the parameters evaluated except for Percentage germination and Percentage tasselling which shows no significant differences with other treatments. DMR-ESR-Y and OBA SUPER 2 among the maize showed a better performance when treated with Imidacloprid before planting while SAMMAZ 15 had a better performance when sprayed with cypermethrin. It can be concluded from this research work that to produce fast-growing plants with a high yield, seeds for these maize varieties should be treated with insecticide before planting.

The Exudation of Surplus Products Links Plant Functional Traits and Plant-Microbial Stoichiometry

The rhizosphere is a hot spot of soil microbial activity and is largely fed by root exudation. The carbon (C) exudation flux, coupled with plant growth, is considered a strategy of plants to facilitate nutrient uptake. C exudation is accompanied by a release of nutrients. Nitrogen (N) and phosphorus (P) co-limit the productivity of the plant-microbial system. Therefore, the C:N:P stoichiometry of exudates should be linked to plant nutrient economies, plant functional traits (PFT) and soil nutrient availability. We aimed to identify the strongest links in C:N:P stoichiometry among all rhizosphere components. A total of eight grass species (from conservative to exploitative) were grown in pots under two different soil C:nutrient conditions for a month. As a result, a wide gradient of plant–microbial–soil interactions were created. A total of 43 variables of plants, exudates, microbial and soil C:N:P stoichiometry, and PFTs were evaluated. The variables were merged into four groups in a network analysis, allowing us to identify the strongest connections among the variables and the biological meaning of these groups. The plant–soil interactions were shaped by soil N availability. Faster-growing plants were associated with lower amounts of mineral N (and P) in the soil solution, inducing a stronger competition for N with microorganisms in the rhizosphere compared to slower-growing plants. The plants responded by enhancing their N use efficiency and root:shoot ratio, and they reduced N losses via exudation. Root growth was supported either by reallocated foliar reserves or by enhanced ammonium uptake, which connected the specific leaf area (SLA) to the mineral N availability in the soil. Rapid plant growth enhanced the exudation flux. The exudates were rich in C and P relative to N compounds and served to release surplus metabolic products. The exudate C:N:P stoichiometry and soil N availability combined to shape the microbial stoichiometry, and N and P mining. In conclusion, the exudate flux and its C:N:P stoichiometry reflected the plant growth rate and nutrient constraints with a high degree of reliability. Furthermore, it mediated the plant–microbial interactions in the rhizosphere.

Genotypic traits and tradeoffs of fast growth in silver birch, a pioneer tree

Fast-growing and slow-growing plant species are suggested to show integrated economics spectrums and the tradeoffs of fast growth are predicted to emerge as susceptibility to herbivory and resource competition. We tested if these predictions also hold for fast-growing and slow-growing genotypes within a silver birch, Betula pendula population. We exposed cloned saplings of 17 genotypes with slow, medium or fast height growth to reduced insect herbivory, using an insecticide, and to increasing resource competition, using naturally varying field plot grass cover. We measured shoot and root growth, ectomycorrhizal (EM) fungal production using ergosterol analysis and soil N transfer to leaves using 15N-labelled pulse of NH4+. We found that fast-growing genotypes grew on average 78% faster, produced 56% and 16% more leaf mass and ergosterol, and showed 78% higher leaf N uptake than slow-growing genotypes. The insecticide decreased leaf damage by 83% and increased shoot growth, leaf growth and leaf N uptake by 38%, 52% and 76%, without differences between the responses of fast-growing and slow-growing genotypes, whereas root mass decreased with increasing grass cover. Shoot and leaf growth of fast-growing genotypes decreased and EM fungal production of slow-growing genotypes increased with increasing grass cover. Our results suggest that fast growth is genotypically associated with higher allocation to EM fungi, better soil N capture and greater leaf production, and that the tradeoff of fast growth is sensitivity to competition, but not to insect herbivory. EM fungi may have a dual role: to support growth of fast-growing genotypes under low grass competition and to maintain growth of slow-growing genotypes under intensifying competition.

Mineralization and nutrient release pattern of vermicast-sawdust mixed media with or without addition of Trichoderma viride.

A combination of vermicast and sawdust mixed medium is commonly used in horticulture, but the added benefit of microbial inoculation and mechanism of nutrient availability are unknown. This study was done to determine nutrient mineralization and nutrient release patterns of different combinations or a mix of vermicast-sawdust growing media amended with or without Trichoderma viride (105 spores/g). The mixed-media treatments were (1) 80% vermicast+20% sawdust; (2) 60% vermicast+40% sawdust; (3) 40% vermicast+60% sawdust; (4) 20% vermicast+80% sawdust; and (5) sawdust alone (control). Total dissolved solids, electric conductivity and salinity increased with each sampling time following submergence in deionized. Nutrients released from media without T. viride were significantly higher than the corresponding media with added T. viride. Overall, the starting total nitrogen of the different media did not change during the incubation period, but nitrate-nitrogen was reduced to a negligible amount by the end of day 30 of incubation. A repeated measures analysis showed a significant effect of Time*T. viride*Treatment on total dissolved solids. Redundancy analysis demonstrated a positive and strong association between media composed of ≥40% vermicast and ≤60% sawdust with or without T. viride and mineral nutrients released, electrical conductivity, total dissolved solids and salinity. These findings suggest that fast-growing plants may benefit from 40% to 60% vermicast added to 40% to 60% sawdust without T. viride while slow-growing plants can benefit from the same mixed medium combined with the addition of T. viride. Further investigation is underway to assess microbial dynamics in the mixed media and their influence on plant growth.

Low glyphosate doses change reproduction and produce tolerant offspring in dense populations of Hordeum vulgare.

Low toxin doses that do not affect mean responses in plant populations can still change the growth of subpopulations. Studies covering vegetative stages ascribed fast-growing plants higher thresholds for growth stimulation and inhibition, compared with the rest of the population. We hypothesized that such selective effects also play a role after reproduction; that is, the offspring of glyphosate-treated tolerant, fast-growing phenotypes is more tolerant than the offspring of untreated plants. An experimental, high-density barley population was exposed to a range of glyphosate concentrations in the greenhouse, and reproduction and final growth were analyzed for selective effects. Therefore, F0, F1 treated and F1 non-treated offspring were re-exposed to glyphosate. Low doses of glyphosate inhibited the growth and reproduction of slow-growing plants at concentrations that did not change the population mean. Concentrations that inhibited average-sized plants hormetically increased the biomass and seed yield of fast-growing plants. Compared with F0 and F1 non-treated offspring, F1-treated offspring from hormetically stimulated fast-growing plants were more glyphosate tolerant. Hence, a pesticide can shape the reproductive pattern of a plant population and alter offspring tolerance at concentrations that have no effect on average yield. Toxin levels that do not change the population mean still alter the reproductive output of individuals. Sensitive phenotypes suffer, whereas the reproduction of tolerant phenotypes is boosted compared with toxin-free conditions. Because glyphosate is one of the leading herbicides in the world, tolerant phenotypes may benefit from current agricultural practices. If these results apply to other toxicants, low toxin doses may increase the fitness of tolerant phenotypes in a way not previously anticipated. © 2021 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Comparison of the single and combined effects of arsenic and antimony on growth and physiology of giant reed (Arundo donax L.).

Fast-growing plant, giant reed (Arundo donax L.) has been gaining a lot of popularity in the phytoremediation of metal-polluted soils. However, information regarding the physiological background of tolerance and accumulation capacity of A. donax with respect to antimony (Sb), arsenic (As), and their co-contamination are very limited. Rooted stem cuttings were grown for 5 months in hydroponics exposed to Sb (10 mg L-1), As (10 mg L-1), and their combined toxicity (Sb 5 mg L-1 + As 5 mg L-1) wherein treatment without As/Sb served as control. Effect of these treatments on key photosynthetic parameters (rate of net photosynthesis, effective quantum yield of photosystem II, chlorophyll fluorescence, and photosynthetic pigments), phytoextraction ability of metalloids, nutrient uptake, root growth, and lignification were analyzed. Arsenic-containing treatments severely affected root morphology of A. donax compared to Sb/control and plants exposed to As showed intensive lignification already in young apical part of the root in the present study. Shoot concentration was found to be 11.35±0.75 Sb mg kg-1 and 8.97±0.52 As mg kg-1 compared to root concentration of 1028.3±19.1 Sb mg kg-1 and 705.3±69.9 As mg kg-1 in the treatments of Sb and As. Even though Sb and As were translocated to the shoots in relatively small amount, both metalloids significantly decreased the shoot and root growth of A. donax and negatively affected the photosynthetic parameters. Moreover, co-contamination of Sb and As proved to be severely toxic to growth and physiology of A. donax even though the magnitudes of the metalloids used were lower than those of Sb/As alone treatments. In conclusion, Sb and As caused a marked reduction in growth and physiological characteristics of A. donax, opposing its use in phytoremediation of highly contaminated soils. Tolerance capacity of plants to simultaneous presence of As and Sb in the environment is crucial for the successful implementation of phytoremediation since the co-contamination by As and Sb might reduce the efficiency of phytoremediation when using this fast-growing and high biomass-producing plant species.

Bioaccumulation of Lead by Pepper Elder (Peperomia pellucida (L.) Kunth) in a Lead-Contaminated Hydroponic System

Lead (Pb) has become one of the most common heavy metal contaminants, demanding research on economical remediation approaches with minimal ecological impacts. Pepper elder (Peperomia pellucida) is a fast-growing plant that can be a candidate for bioaccumulation and phytoremediation. In this study, the lead bioaccumulation of P. pellucida was assessed by determining the growth response and absorptive capacity of the plant. Plants were grown in hydroponic solution spiked with 500 mg/L of Pb for 28 days. Growth response, absorptive capacity and tolerance of plants grown in contaminated nutrient solution were determined in comparison with control plants. After 28 days of exposure, lead phytotoxicity symptoms such as wilting, chlorosis and necrosis were observed on some plants. The control plants recorded 3.08 g total dry weight (DW) compared to the 1.35 g in Pb-contaminated plants. The tolerance index (TI) of P. pellucida was at 43.40%. The plants were able to absorb lead, with the concentration of lead in the roots (158.6 µg/g) being greater than the concentration of the metal in the shoots (43.2 µg/g). Meanwhile, bioconcentration factor (BCF) and translocation factor (TF) values were recorded at 0.40 and 0.27, respectively. BCF criterion indicates that the plant is not suitable for phytoextraction, but TF value shows that the plant can be a potential excluder. The findings of the study show that P. pellucida accumulated considerable amount of lead within its tissues, indicating that the plants may be further exploited for their capacity to absorb heavy metals by tweaking several factors that may affect its bioaccumulation ability.

Linking plant hydraulics and the fast-slow continuum to understand resilience to drought in tropical ecosystems.

Tropical ecosystems have the highest levels of biodiversity, cycle more water and absorb more carbon than any other terrestrial ecosystem on Earth. Consequently, these ecosystems are extremely important components of Earth's climatic system and biogeochemical cycles. Plant hydraulics is an essential discipline to understand and predict the dynamics of tropical vegetation in scenarios of changing water availability. Using published plant hydraulic data we show that the trade-off between drought avoidance (expressed as deep-rooting, deciduousness and capacitance) and hydraulic safety (P50 - the water potential when plants lose 50% of their maximum hydraulic conductivity) is a major axis of physiological variation across tropical ecosystems. We also propose a novel and independent axis of hydraulic trait variation linking vulnerability to hydraulic failure (expressed as the hydraulic safety margin (HSM)) and growth, where inherent fast-growing plants have lower HSM compared to slow-growing plants. We surmise that soil nutrients are fundamental drivers of tropical community assembly determining the distribution and abundance of the slow-safe/fast-risky strategies. We conclude showing that including either the growth-HSM or the resistance-avoidance trade-off in models can make simulated tropical rainforest communities substantially more vulnerable to drought than similar communities without the trade-off. These results suggest that vegetation models need to represent hydraulic trade-off axes to accurately project the functioning and distribution of tropical ecosystems.

Plant evolution along the ‘fast–slow’ growth economics spectrum under altered precipitation regimes

Plants have evolved different strategies to withstand drought. In general, these strategies can be defined along a plant economics spectrum, which classifies plants depending on whether their growth rate is fast or slow, where fast growth is associated with high mortality, high water use, and high sensitivity to drought. Which strategy along this economy spectrum will be selected under different precipitation regimes is an open question. We address this question with a minimal soil–plant model in which a single plant economy trait related to growth rate characterizes the plant strategy. This generic and dimensionless trait influences both recruitment and mortality, but not background mortality. We explore the evolution of this trait by quantifying its effects on birth, mortality, and transpiration rates. Furthermore, we explore the influence of direct plant density dependence acting on recruitment and mortality, in addition to the indirect density dependence caused by plant feedback on soil water content.We show that: (1) Increasingly fast-growing plants always evolve under increasing background mortality. (2) When soil water only depends on plant density and is independent of precipitation and abiotic water losses, the strategy minimizing soil water content is an evolutionarily stable strategy (ESS); i.e., the evolutionary outcome is a tragedy of the commons (Hardin, 1968). (3) When precipitation, abiotic water losses and trait dependent transpiration determine soil water content, the ESS lies between the strategy maximizing plant density and that minimizing soil water content; i.e., no tragedy of the commons occurs. (4) With a deterministic precipitation model and density dependence acting directly only on recruitment, higher precipitation promotes the evolution of faster plants. The opposite result is found when density dependence is acting directly only on mortality. (5) Similar trends in the economy trait are observed when forcing the model with stochastic precipitation events.

The use of yellow velvetleaf (Limnocharis flava) as a natural color for colet technique using cold wax

Yellow velvetleaf is a fast-growing plant. It cannot be optimally used, particularly the old leaves. Old yellow velvetleaf waste has not been used appropriately, even though it has more benefits and value. The leaves of yellow velvetleaf contain natural color of carotenoids and flavonoids which can be used for natural dyes. The potential color produced can possibly be applied for textile coloring colet technique using cold wax. The research method was carried out through experiments and data analysis using descriptive analysis. The results show that yellow velvetleaf can be used for colet coloring technique using cold wax, and the resulted colors differs depending on the mordant used. Color aging test shows that during the process of nglorod (wax exfoliating) using water, the darkest color was found in tunjung mordant with a color different of 81-100, belongs to “very dark” category. The test of fastness to rubbing shows score of 4 (good) for all samples. The highest result for motif sharpness test is found in the process of nglorod with water and tunjung mordant with color different of 81-100, which is categorized as “very sharp”.