Leaf Wettability Research Articles

Microfluidic-Based dsRNA Delivery Nanoplatform for Efficient Spodoptera exigua Control.

Nanotechnology-based RNA interference (RNAi) offers a promising approach to pest control. However, current methods for producing RNAi nanopesticides are mainly implemented in a batch-to-batch manner, lacking consistent quality control. Herein, we present a microfluidic-based nanoplatform for RNA nanopesticide preparation using lipid nanoparticles (LNPs) as nanocarriers, taking advantage of the enhanced mass transfer and continuous processing capabilities of microfluidic technology. The dsRNA@LNPs were rapidly formed within seconds, which showed uniform size distribution, improved leaf wettability, and excellent dispersion properties. The delivery efficiency of dsRNA@LNPs was evaluated by targeting the chitin synthetase B (CHSB) gene ofSpodoptera exigua. The dsRNA@LNPs can effectively resist nuclease-rich midgut fluid degradation. Importantly, dsCHSB@LNPs exhibited increased mortality rates, significant reduction of larvae growth, and enhanced gene suppression efficiency. Therefore, a continuous nanoplatform for RNAi nanopesticide preparation is demonstrated by utilizing microfluidic technology, representing a new route to produce RNAi nanopesticides with enhanced quality control and might accelerate their practical applications.

Dissecting wheat above-ground architecture for enhanced water use efficiency and grain yield in the subtropics

BackgroundGrowing wheat under climate change scenarios challenges, scientists to develop drought and heat-tolerant genotypes. The adaptive traits should therefore be explored and engineered for this purpose. Thus, this study aimed to dissect surface traits and optimizing the leaf architecture to enhance water use efficiency (WUE) and grain yield. Twenty-six wheat genotypes were assessed for five novel leaf traits (NLTs: leaf prickle hairs, groove type, rolling, angle and wettability) under normal, drought and heat conditions following triplicated factorial randomized complete block design (RCBD). The data for NLTs, physiological traits (stomatal conductance, WUE, transpiration, and photosynthesis), and standard morphological and yield traits were recorded. Leaves were sampled at the stem elongation stage (Zadoks 34) to measure the leaf water content (%), contact angle, and to obtain pictures through scanning electron microscopy (SEM). The air moisture harvesting efficiency was evaluated for five selected genotypes. The ideotype concept was applied to evaluate the best-performing genotypes.ResultsThe correlation analysis indicated that long leaf prickle hairs (> 100 μm), short stomatal aperture and density (40–60 mm− 2), inward to spiral leaf rolling, medium leaf indentation, low contact angle hysteresis (< 10°), and cuticular wax were positively associated with WUE. This, in turn, was significantly correlated to grain yield. Thus, the genotypes (E-1) with these traits and alternate leaf wettability had maximum grain yield (502 g m− 2) and WUE supported with high photosynthesis rate, and relative water content (94 and 75% under normal and stress conditions, respectively). However, the genotype (1-hooded) with dense leaf hairs on edges but droopy leaves, spiral leaf rolling, and lighter groove, also performed better in terms of grain yield (450 g m− 2) under heat stress conditions by maintaining high photosynthesis and WUE with low stomatal conductance and transpiration rate.ConclusionThe SEM analysis verified that the density of hairs on the leaf surface and epicuticular wax contributes towards alternate wettability patterns thereby increasing the water-use efficiency and yield of the wheat plant. This study paves a way towards screening and and developing heat and drought-tolerant cultivars that are water-saving and climate-resilient.

A causal trait model for explaining foliar water uptake capacity

AbstractQuestionsPlants largely vary in their capacity for foliar water uptake (FWU), that is, the capacity to increase leaf water content by directly absorbing water from leaf‐wetting events. Climate change will reduce leaf wetting and increase drought events. Therefore, we need a better understanding of the underlying traits and mechanisms that facilitate FWU.LocationSeasonally dry tropical montane grasslands in Brazil (Campos de Altitude).MethodsWe measured FWU and leaf traits related to wettability, surface conductance, water potential and water storage on up to 55 plant species. By using Direct Acyclic Graph theory and Bayesian modelling, we tested how those leaf traits affect FWU.ResultsWe found that stomatal conductance largely explained interspecific variation in FWU, which was also favoured in species with hydrophilic leaves, high cuticular conductance, more negative leaf water potentials, low dry‐matter content, isohydric behaviour, and more elastic cell walls.ConclusionsDue to the existence of trade‐offs, not all species exhibit an optimal combination of traits that favours FWU. Instead, co‐occurring species have achieved a similar capacity for FWU through distinct trait combinations. Consequently, species engaged in FWU may exhibit differential vulnerabilities to climate change as they can cope with drought using other strategies beside FWU.

Physiological Responses and Ecological Benefits of Water Uptake by Populus euphratica Leaves in Arid Areas

The absorption of atmospheric water by plants through their leaves, known as leaf water uptake, plays a crucial role in sustaining plant growth and survival in arid regions. Condensate is one of the important sources of water for plants in arid zones and plays an important role in alleviating the physiological state of plant water. In order to clarify the ecological role of the leaf absorption of condensation water, we took the dominant species of the desert Dugay forest plant, Populus euphratica, as the research object, and based on in situ leaf humidification field experiments, we comprehensively analyzed the effect of condensation water on the physiological state of P. euphratica and the ecological benefit of leaf water absorption on the arid zone by determining the parameters of the physiological indexes of the leaf, the leaf wettability, and the water-absorbing capacity of the leaf. The results showed that P. euphratica leaves have a water-absorbing ability on both sides, and under the condensation water treatment, the water potential of dawn leaves in the TR group (−1.75 ± 0.12 MPa) was significantly higher than that in the CK group (−1.41 ± 0.13 Mpa); the net photosynthetic rate of leaves in the TR group (13.08 ± 0.68 μmol·m−2·s−1) was significantly higher than that in the CK group (10.42 ± 0.57 μmol·m−2·s−1); the proline content of the TR group (22.82 ± 0.8 μg·g−1) was significantly lower than that of the CK group (68.67 ± 6.14 μg·g−1); and the leaf photosynthetic capacity, leaf osmotic adjustment, and stress tolerance affected by condensation water were significantly different (p &lt; 0.05). A leaf’s water-absorbing ability is mainly affected by leaf wettability, the proline content, and other influencing factors. The mean FWU rate was positively correlated with the mean transpiration rate. Within the Ebinur Lake watershed, the water absorption rate of P. euphratica leaves accounts for 10.92% of the maximum transpiration rate (Tr); in 2022, the total summer leaf surface water uptake by P. euphratica was about 220.5 mol, a value that represents about 0.25% of the average annual evapotranspiration from Ebinur Lake. This study helps to improve the understanding of the impact of condensation water on the physiological ecology of the desert plant P. euphratica and provides a scientific basis for the ecological benefits of leaf water absorption in arid regions.

Ocena użyteczności metody Bikermana do wyznaczania kątów zwilżania liści

The physico-chemical properties of the spray liquid affect the efficiency and effectiveness of crop protection treatments. A measure of leaf wettability is the wetting angle, the testing of which is neglected in routinely performed spraying. In the search for a method useful for determining leaf wetting angle for crop protection treatments, the method that Bikerman (1941) applied to the surface of the object observed from above was evaluated. The assumptions of the method and the resulting opportunities and constraints in its application are presented in this paper. The influence of leaf, liquid and droplet properties on the wetting angle was discussed. It was concluded that Bikerman’s method is suitable for determining leaf wetting angles over a wide range of physical properties of liquids used in crop protection treatments.

Wetting behavior on wheat leaves surface by adding different surfactants

The wettability of chemical pesticides on the surfaces of crop leaves is crucial for enhancing the efficiency of chemical solutions. This work examined the wetting behavior of 28-Epimotabrassinolide (28-HB) combined with various surfactants on the adaxial and abaxial leaves at the jointing and boot stages of wheat. The microstructure of the leaf surface was characterized by ultra-depth microscopy, and the surface free energy (SFE) of the leaf was calculated by the Owens–Wendt–Rabel–Kaelble (OWRK) method. The surface tension of the 28-HB solution with different surfactants added and the contact angle on the leaf surface at the jointing and boot stages were measured. Compared with the boot stage, the wettability of the adaxial and abaxial wheat leaves was superior to that of the jointing stage. The addition of surfactants to the 28-HB improved the spreading behavior of droplets on the surface of leaves. Specifically, when fatty lcohol polyoxyethylene ether (AEO9) was added to 28-HB, the wettability of the droplets on the jointing wheat leaf surface was greatly enhanced. Additionally, cetyltrimethylammonium bromide (CTAB) and sodium lauryl sulfate (SDS) improve the wettability of 28-HB on wheat leaves at the boot stage. When the surface tension of the solution is lower than the free energy of the solid surface, the dispersion component in the free energy of the leaf surface aligns with the dispersion component in the surface tension of the solution, facilitating maximum wettability of the solution on the leaf surface. This work offers a fresh perspective on enhancing the efficiency of surfactants in achieving superhydrophobic leaf wetting.

Factors influencing the difference in dissolved ion inputs to the forest floor between deciduous and coniferous stands: comparison under high and low atmospheric deposition conditions

It is necessary to clear the relationship between physical and vegetation factors on the processes governing dissolved ion inputs to the forest floor to estimate correctly the values of atmospheric input to the forest. This study identified the factors influencing the differences in dissolved ion inputs to the forest floor between coniferous evergreen and broad-leaved deciduous species by analyzing the phenological variations of dry deposition and canopy exchange calculated by the canopy budget model under a high-deposition site near the city of Tokyo and a low-deposition site 84 km further away. At low-deposition site, vegetation factors such as capture efficiency did not explain the differences in Na+ or Cl− dry deposition. Leaf physiological characteristics influenced the differences in the Mg2+ and Ca2+ canopy leaching values, and phenology, leaf wettability, and diffusion processes from water film into leaves influenced the differences in NH4+ and NO3− input processes between tree types. At the high-deposition site, differences in the dry deposition of Na+, SO42−, Cl−, Mg2+, Ca2+, NH4+, and NO3− between tree types were influenced by differences in capture efficiency between coniferous and broad-leaved canopies in the leafed period and by the absence of leaves in deciduous species after leaf fall. These results indicated that atmospheric deposition affected the capture efficiency of coniferous trees for dry deposition and enhanced the difference of dissolved ion inputs to the forest floor between coniferous and deciduous species.

Leaf wettability is the main driver for foliar P uptake in P-deficient maize

Foliar fertilisation is an alternative form of nutrient application, which is of particular interest for phosphorus (P), where the efficiency of soil fertilisation is low. However, the uptake of foliar-applied nutrients is insufficiently characterised. The aim of this study was to investigate the individual and combined significance of wettability, foliar fertiliser properties and surfactant on foliar P uptake in P-deficient maize (Zea mays L.). Sorption and desorption properties of two P salts used as foliar fertilisers (KH2PO4, K2HPO4) were determined with dynamic vapor sorption isotherms. Leaf surfaces and foliar spray depositions of two differently wettable maize cultivars were investigated by scanning electron microscopy and contact angle measurement. Phosphorus uptake was then linked to leaf and fertiliser solution properties and its effect on cell ultrastructure was characterised by transmission electron microscopy. Wettability was the key factor for P absorption, as all foliar fertilisers were taken up reaching a tissue-P level of adequately nourished plants. For unwettable leaves, only solutions with surfactant, especially the combination of surfactant and hygroscopic P salt (K2HPO4) were taken up. This study provides novel insights into the significance of leaf surface and fertiliser properties, which can thus contribute to an improvement of P fertilisation strategies.

Leaf surface features of maize cultivars and response to foliar phosphorus application: effect of leaf stage and plant phosphorus status.

Soil phosphorus (P) application is the most common fertilisation technique but may involve constraints due to chemical fixation and microbial immobilisation. Furthermore, excessive P fertilisation leads to P runoff into water bodies, threatening ecosystems, so targeted foliar P fertilisation is an interesting alternative. This study aimed to determine the importance of leaf surface characteristics for foliar P uptake in P-deficient maize (Zea mays L.). The leaf surface of four maize cultivars was characterised by electron microscopy, Fourier transform infrared spectroscopy and contact angle measurements. Uptake of foliar-applied P by maize cultivars was estimated, measuring also leaf photosynthetic rates after foliar P spraying. Plants of cultivar P7948 were found to be wettable from the 4th leaf in acropetal direction, whereas other cultivars were unwettable until the 6th leaf had developed. Minor variations in stomatal number and cuticle composition were recorded, but no differences in foliar P absorption were observed between cultivars. Nevertheless, cultivars showed variation in the improvement of photosynthetic capacity following foliar P application. Phosphorus deficiency resulted in ultrastructural disorganisation of mesophyll cells and chloroplasts, which impaired photosynthetic performance, yet there was no effect on stomatal frequency and leaf wettability. This study provides new insights into the influence of P deficiency and cultivar on leaf surface characteristics, foliar P uptake and its effect on physiological processes. Understanding the relationships between leaf characteristics and P uptake allows a more targeted evaluation of foliar P fertilisation as an application technique and contributes to the understanding of foliar uptake mechanisms.

Multifunctional Mesoporous Silica Nanosheets for Smart Pesticide Delivery and Enhancing Pesticide Deposition.

A multifunctional nanopesticide delivery system is considered to be a novel and efficient tool for controlling pests in modern agriculture. In this study, a mesoporous silica nanosheet (H-MSN) carrier for intelligent delivery of pesticides was prepared by the sol-gel method. The prepared H-MSN carrier had obvious hexagonal flat structure, with a specific surface area of 759.9 m2/g, a transverse diameter of about 340 nm, a thickness of about 80 nm, and regular channels being perpendicular to the plane. Polyethylene glycol diacrylate (PEGDA) and sulfhydryl-modified polyethylenimide (PEI-SH) were used to block the insecticide after loading the insecticide imidacloprid (IMI). The introduction of hydrophilic PEI-SH/PEGDA greatly improved the leaf wettability and adhesion ability of H-MSN. The retention amount of IMI@H-MSN@PEI-SH/PEGDA on cucumber and cabbage leaves was up to 46.0 mg/cm2 and 19.0 mg/cm2, respectively. IMI@H-MSN@PEI-SH/PEGDA showed pH- and GSH-responsive release. Compared with pure IMI, IMI entrapped in MSN carriers has favorable biocompatibility and antiphotolytic properties.

In vivo sensing to monitor tomato plants in field conditions and optimize crop water management

Irrigation is key to increasing crop yield and meeting the global demand for food. This study reports the assessment of tomato water consumption by bioristor, a new in vivo an Organic ElectroChemical Transistor-based biosensor. Bioristor enables direct, real-time acquisition of biophysical information about the plant’s water requirements directly from the plant sap, and thus the water input can be adjusted accordingly.The aim of this study is to demonstrate the efficacy of bioristor in rapidly detecting changes in the plant’s water status enhancing water use and irrigation efficiency in tomato cultivation with significant savings in the water supply. To this end, experiments were carried out in 2018 and 2020 in Parma (Italy) in tomato fields under different water regimes. The sensor response index (R) produced by bioristor recorded the real time plant health status, highlighting an excess in the water supplied as well as the occurrence of drought stress during the growing season. In both years, bioristor showed that the amount of water supplied could have been reduced by 36% or more. Bioristor also measured the timing and duration of leaf wetting: 438 h and 409 h in 2018 and 2020, respectively. These results open up new perspectives in irrigation efficiency and in more sustainable approaches to pesticide application procedures.

Sustained Agricultural Spraying: From Leaf Wettability to Dynamic Droplet Impact Behavior.

Crop production and quality safety system have the potential to nurture human health and improve environmental sustainability. Providing a growing global population with sufficient and healthy food is an immediate challenge. However, this system largely depends on the spraying of agrochemicals. Crop leaves are covered with different microstructures, exhibiting distinct hydrophilic, hydrophobic, or even superhydrophobic wetting characteristics, thus leading to various deposition difficulties of sprayed droplets. Here, the relationship between wettability and surface microstructure in different crop leaves from biological and interfacial structural perspectives is systematically demonstrated. A relational model is proposed in which complex microstructures lead to stronger leaf hydrophobicity. And adding surfactant with a faster dynamically migrating velocity and reducing droplet size can improve agrochemical precise deposition. These contribute toward highly accurate and efficient targeted applications with fewer agrochemicals use and promote sustainable models of eco-friendly agriculture systems.

Phenotypic plasticity in leaf traits in response to experimental precipitation increase: Wettability, foliar water uptake and gas exchange

AbstractWater availability is one of the factors affecting plant growth and development, especially in arid and semiarid environments. Changes in precipitation due climate change alter water availability to plants impacting on plant physiology. Numerous studies have focused on plant response to reduced precipitation and less on the effects of increased precipitation. The main objective of this study was to evaluate biophysical and physiological leaf traits in response to experimental water addition in four dominant shrubs and one grass species in a Patagonian steppe, during the dry season. The experiment consisted of two treatments: control and water addition, increasing the average annual rainfall by 25% during 6 years. We measured leaf wettability, water status, transpiration, photosynthesis, stomatal conductance, water use efficiency and foliar water uptake (FWU). In addition, we determined the phenotypic plasticity index of these evaluated traits. We expected lower FWU and higher transpiration and photosynthesis rates due changes in leaf surface properties under water addition treatment. All study species responded significantly to treatment with higher loss of water per transpiration and lower FWU. Also, all species increased photosynthesis rate and water use efficiency (WUE). However, water potential and leaf wettability did not change with higher precipitation. Thus, higher phenotypic plasticity was observed in functional than in morphological traits. Since functional traits were more sensitive than leaf surface traits, plants may quickly take advantage when environmental conditions tend to be more favourable to growth. Our findings suggest that plants of Patagonian steppe have adaptive ability to respond to environmental changes through plastic responses.

High potential for foliar water uptake in early stages of leaf development of three woody angiosperms.

Foliar water uptake (FWU) is a widespread mechanism that may help plants cope with drought stress in a wide range of ecosystems. FWU can be affected by various leaf traits, which change during leaf development. We exposed cut and dehydrated leaves to rainwater and measured FWU, changes in leaf water potential after 19 h of FWU (ΔΨ), minimum leaf conductance (gmin ), and leaf wettability (abaxial and adaxial) of leaves of Acer platanoides, Fagus sylvatica, and Sambucus nigra at three developmental stages: unfolding (2-5-day-old), young (1.5-week-old) and mature leaves (8-week-old). FWU and gmin were higher in younger leaves. ΔΨ corresponded to FWU and gmin in all cases but mature leaves of F. sylvatica, where ΔΨ was highest. Most leaves were highly wettable, and at least one leaf surface (adaxial or abaxial) showed a decrease in wettability from unfolding to mature leaves. Young leaves of all studied species showed FWU (unfolding leaves: 14.8 ± 1.1 μmol m-2 s-1 ), which may improve plant water status and thus counterbalance spring transpirational losses due to high gmin . The high wettability of young leaves probably supported FWU. We observed particularly high FWU and respective high ΔΨ in older leaves of F. sylvatica, possibly aided by trichomes.

Synergistic Effect of Orange Oil Adjuvant on Acetamiprid in the Control of Edentatipsylla shanghaiensis

We explore the effects of orange oil adjuvant (a kind of spray adjuvant) on the physicochemical properties of acetamiprid (pesticide) when foliage-applied to the surface of pittosporum tobira leaves. The leaf surface was characterized by the OCG (Van Oss–Chaudhury–Good) method, and the relationship between the wetting behavior of various pesticide droplets, including the change in surface free energy (SFE), adhesion force, and adhesion work, is explored to offer insight into the control of the pittosporum tobira psyllid, Edentatipsylla shanghaiensis Li et Chen. Results showed that SFE values for the adaxial and adaxial leaf surfaces were 40.13 mJ/m2 and 37.06 mJ/m2, respectively, while acetamiprid liquids had SFE values of 67.43 mJ/m2 and 63.26 mJ/m2. SFE values of the acetamiprid liquids are greater than that of the leaf surface, and the droplets on the leaves with a smaller adhesion force and lager adhesion work exhibited moderate-to-poor wettability estimated by contact angles. When the concentration of the orange oil adjuvant was between 0.10% and 1.00% above CMC (critical micellar concentration, 0.09%), the SFE values of the acetamiprid liquids were less than that of the leaf surface. The adhesion tension was greatly increased, and the adhesion work decreased by 14.46–28.13%. Meanwhile, droplets on the leaves exhibited good wettability. Field experiments showed that the synergistic effect of acetamiprid against E. shanghaiensis was significantly improved after spraying with orange oil adjuvant at the concentrations 0.10% and 1.0% above CMC. This study demonstrated the use of an orange oil adjuvant with a concentration above CMC to improve the synergistic effect of the insecticide directly through improved leaf wetting, which can provide reference for reducing pesticide dosage and increasing efficiency during the chemical control of pests.

Evaluating Leaf Wettability and Salt Hygroscopicity as Drivers for Foliar Absorption.

The objective of this study was to evaluate the rate of foliar absorption of magnesium (Mg) salts with different deliquescence and efflorescence relative humidity values (DRH and ERH, also known as point of deliquescence (POD) and point of efflorescence (POE), respectively) when supplied to leaves of model plants with different wettability properties. For this purpose, a greenhouse pot experiment was conducted with lettuce (very wettable), broccoli (highly unwettable) and leek (highly unwettable). Foliar sprays contained 0.1% surfactant plus 100 mM Mg supplied as MgCl2·6H2O, Mg(NO3)2·6H2O or MgSO4·7H2O. Leaf Mg concentrations were determined 1 and 7 days after foliar application. Anion concentrations were also measured in lettuce where a significant foliar Mg absorption was detected. Leaf wettability, leaf surface free energy and fertilizer drop deposit appearance onto the foliage were assessed. It is concluded that despite including a surfactant in the spray formulation, leaf wettability plays a major role in foliar Mg absorption.

A Case Study of Leaf Wettability Variability and the Relations with Leaf Traits and Surface Water Storage for Urban Landscape Plants

Leaf wettability, the affinity of a leaf surface to water droplets, affects the interactions between leaves and external environments. This study aimed to determine the interspecific and seasonal variabilities of leaf wettability across 30 common landscape plants, and their relationships with leaf functional traits, surface micromorphology and rainfall interception in Hefei city, China. Results indicated that leaf wettability was species-specific, and the adaxial and abaxial contact angles ranged from 63° to 134° and 66° to 134°, respectively, with the adaxial surface proving more wettable. Leaf wettability gradually increased from spring to winter. Classification of life forms revealed that there were no significant wettability differences among trees, shrubs and herbs, and between evergreen and deciduous plants, but deciduous plants’ wettability increased more significantly in winter. Leaf wettability was not significantly correlated with any leaf functional traits. Single surface microscopic parameters also had low correlations with leaf wettability. Instead, the low-wettability species were found to possess more prominent epidermis cells, dense waxy layers or trichomes on leaf surfaces. Leaf wettability was the best predictor of surface rainwater storage within all functional traits. Our results highlighted that leaf wettability was variable between different species and growth periods due to micromorphological differences, and significantly affected rainfall interception at the leaf scale, which may have great significance for evaluating plant hydrological function in urban areas.

Leaf wettability and plant surface water storage for common wetland species of the Biebrza peatlands (northeast Poland)

Abstract Wetlands play a crucial role in buffering the effects of climate change. At the same time, they are one of the most endangered ecosystems on the globe. The knowledge of the water cycle and energy exchange is crucial for the practical preservation and exploiting their capabilities. Leaf wettability is an important parameter characterising the plant's ability to retain water on its surface, and is linked to the ecosystems' hydrological and ecological functioning. This research investigates the relationship between leaves' wettability based on contact angle measurements and water storage capacity (interception) for wetland vegetation. We performed the study for ten common plant species collected from Biebrza peatlands (Poland). We used CAM100 goniometer for the wetting contact angle measurements on the leaves' surface, and the weighing method for the plant surface water storage determination. The wetland plants' initial contact angle values ranged from 64.7° to 139.5° and 62.4° to 134.0° for the leaves' adaxial and abaxial parts, respectively. The average plant surface water storage was equal to 0.31 g·g−1, and values ranged from 0.09 to 0.76 g·g−1. The leaf hydrophobicity contributes to the amount of retained water. With increasing average contact angle, the amount of water retained on the plant decreased.

Impact of longevity and wettability of fern leaves on epiphyll colonization in a Mexican lowland rainforest

AbstractQuestionsLeaf traits play an important role in the epiphyll colonization of leaves. Although ferns are common in forest understories, they have been widely ignored as possible host plants. We asked: How does epiphyll colonization (cover, richness, and composition) differ among fern species depending on their leaf longevity and surface wettability?LocationTropical Biological Station of “Los Tuxtlas”, Veracruz (Mexico).MethodsEpiphyll cover was monitored on leaves of six individuals per species after 2, 5, 12, 16.5, and 26 months. Leaf longevity was calculated from leaf turnover rates over 24 months. Leaf wettability was determined through the contact angle technique.ResultsAll studied fern species had hydrophilic leaf surfaces. Fern species with shorter leaf longevity (14.4–17.8 months) were colonized faster by epiphylls than species with longer leaf life spans (33.9–38.8 months). The area of the oldest leaves was covered to 1.2%–26.1% by foliicolous lichens and to 0.3%–2.2% by green algae. Foliicolous lichens were more species‐rich on Danaea nodosa (27 spp.) than on the other fern species (1–9 lichen spp.). Foliose liverworts thrived on the only riparian fern (3.57%). Only 0.04%–1.1% of the area of plastic substrates was colonized by epiphylls.ConclusionsThe hydrophilic leaf surfaces of ferns facilitated the colonization of epiphylls, especially of foliicolous lichens. The speed of epiphyll colonization was faster in ferns with shorter leaf longevity but increased in all species with leaf age. However, the relatively low epiphyll cover on fern leaves and artificial substrates in our study might be related to unfavorable microclimatic parameters.

Effects of Leaf Hydrophilicity and Stomatal Regulation on Foliar Water Uptake Capacity of Desert Plants

Foliar water uptake (FWU) is one of the primary water sources for desert plants. Desert plants’ water uptake capacity is essential in maintaining the balance of carbon and water. However, there are few studies on FWU capacity in desert plants and the physiological and ecological characteristics that lead to differences in FWU capacity. In order to clarify FWU strategies and the influencing factors of plants in desert ecosystems, this study measured the contact angle, FWU parameters, and hydraulic parameters to explore six desert plants’ FWU capacity and the effects of leaf wettability and hydraulic parameters on FWU capacity. The results showed that all six plants had FWU capacity, among which the leaves of Nitraria sibirica Pall. and Halimodendron halodendron (Pall.) Voss had a high foliar water uptake rate (k) and high foliar water uptake accumulation (FWU storage), and the leaves of Glycyrrhiza uralensis Fisch. had a high k and low FWU storage. The leaves of Populus euphratica Oliv., Apocynum hendersonii Hook. f., and Alhagi sparsifolia Shap. had a low k and low FWU storage. Additionally, FWU capacity was mainly affected by stomatal regulation compared with leaf wettability and leaf structure. The results of this study will help to improve the understanding of the physiological and ecological adaptability of desert plants.