Visual rating and the use of image analysis for assessing canopy density in a pecan provenance collection during leaf fall

A collection representing the native range of pecan was planted at the US DA-ARS Southeastern Fruit and Tree Nut Research Station,Byron,GA.The collection(867 trees)is a valuable genetic resource for characterizing important horticultural traits.Canopy density during leaf fall is important as the seasonal canopy dynamics provides insights to environmental cues and breeding potential of germplasm.The ability of visual raters to estimate canopy density on a subset of the provenance collection(76 trees)as an indicator of leaf shed during autumn along with image analysis values was explored.Mean canopy density using the image analysis software was less compared to visual estimates(11.9%vs 18.4%,respectively).At higher canopy densities,the raters overestimated foliage density,but overall agreement between raters and measured values was good(ρc=0.849 to 0.915),and inter-rater reliability was high(R^(2)=0.910 to 0.953).The provenance from Missouri(MOL),the northernmost provenance,had the lowest canopy density in November,and results show that the higher the latitude of the provenance,the lower the canopy density.Based on regression,the source provenance latitude explained 0.609 of the variation using image analysis,and0.551 to 0.640 when based on the rater estimates of canopy density.Visual assessment of pecan canopy density due to late season leaf fall for comparing pecan genotypes provides accurate and reliable estimates and could be used in future studies of the whole provenance collection.

Direct measurement of the three-dimensional distribution of leaf area density and light conditions in a mature oak stand by the cube method

Although the distributions of foliage and light play major roles in various forest functions,accurate,nondestructive measurement of these distributions is difficult due to the complexity of the canopy structure.To evaluate the foliage and light distributions directly and nondestructively in a mature oak stand,we used the cube method by dividing the forest canopy into small cubes(50 cm per side)and directly measured leaf area density(LAD,the total one-sided leaf area per unit volume,i.e.,cube)and relative irradiance(RI)within each cube.The distribution of LAD and of RI was highly heterogeneous,even at the same canopy height.This heterogeneity reflected the presence of foliage clusters associated with multiple forking branches.The relationship between cumulative LAD at the canopy surface and average RI followed the Beer-Lambert law.The mean light extinction coefficient(K)was 0.32.However,K was overestimated by more than double(0.80)when calculated based on the classical method using RI at the forest floor.This overestimation was caused by the lower RI due to light absorption by nonleaf plant parts below the canopy.Our findings on the complex foliage and light distributions in canopy layers should help improve the accuracy of RI and K measurements and thus more accurate predictions of environmental responses and forest functions.

Study on the Introduction of Plants with Colored Foliage in Zhengzhou Area and Their Adaptability

[Objective] This study aimed to preliminarily select the plants with colored foliage adaptable to Zhengzhou area. [Method] An introduction trial on 42 varieties with colored foliage was conducted, in which major ornamental characteristics, phenological phases and stress resistance of all the introduced plants with colored foliage were observed and the introduced plants were comprehensively evaluated. [Result] Golden-and Compound-leaved Maple, Red-leaved Sakura, Pink-and Compound-leaved Maple, Amur Maple, Purple-leaved Canadian Redbud with good performance were selected preliminarily, which can be applied for landscape in Zhengzhou area. Among them, Golden- and Compound-leaved Maple, Golden- and Silvery-leaved Maple and Purple-leaved Smoketree can either be planted separately, or in a line as boulevard trees, or in groups as ornamental forest; Red-leaved Sakura, Pink- and Compound-leaved Maple and Purple-leaved Canadian Redbud can be planted in groups or separately in gardens, parks or alongside streets or in front of buildings; Amur Maple with high adaptability is a excellent tree species for afforesting barren mountain. [Conclusion] This study has not only provided new excellent germplasm sources for the landscaping in Zhengzhou area, thus favoring the improvement of local landscaping level, but also provides examples and references for the introduction of plants with colored foliage in the other areas.

Mitigative Effects of Foliage Spraying and Root Irrigation of ALA on Banana Plantlets Exposed to Cold Stress

[Objective] This study aimed to investigate the effect of ALA applied by foliage spraying and root irrigation on banana plantlets exposed to cold stress. [Method] After applied by foliage spraying and root irrigation with 5-aminolevulinic acid （ALA） at four different concentrations, ＂Brazil banana＂ plantlets were placed in artificial climate boxes at 7 ℃ to imitate low-temperature stress. [Result] The results showed that ALA application by both foliage spraying and root application can significantly increase SOD and POD activities, and reduce O2- generation rate, MDA content and relative conductivity in leaves of banana plantlets, as well as raising proline content, soluble protein content and relative water content, and maintaining the stability of chlorophyll. Foliage application of ALA within concentration range of 0.505.00 mg/L had best effect, which increased the chlorophyll content and reduced the relative conductivity and MDA content significantly compared to root irrigation at the same concentration, and raised SOD and POD activities by 64.5% and 12.3% respectively at 5 mg/L compared to their counterparts by root irrigation. [Conclusion] Foliage spraying of ALA can better mitigate the injuries to banana plantlets caused by low-temperature stress.

Differences in leaf functional traits between red and green leaves of two evergreen shrubs Photinia×fraseri and Osmanthus fragrans

Leaf functional traits are adaptations that enable plants to live under different environmental conditions. This study aims to evaluate the differences in leaf functional traits between red and green leaves of two evergreen shrubs Photinia × fraseri and Osrnanthus fragrans. Specific areas of red leaves are higher than that of green leaves in both species. Thus, the material investment per unit area and per lamina of red leaves is significantly lower than that of green leaves, implying an utmost effort of red leaves to increase light capture and use efficiency because of their low leafchlorophyll concentration. The higher petiole length of green leaves compared with that of red leaves indicates that adult green leaves may have large fractional biomass allocation to support the lamina structures in capturing light with maximum efficiency and obtaining a high growth rate. The high range of the phenotypic plasticity of leaf size, leaf thickness, single-leaf wet and dry weights, and leaf moisture of green leaves may be beneficial in achieving efficient control of water loss and nutrient deprivation. The high range of phenotypic plasticity of leaf chlorophyll concentration of red leaves may be advantageous in increasing resource （especially light） capture anduse efficiency because this leaf type is juvenile in the growth stage and has low leaf-chlorophyll concentration.

Study on roughness coefficient for unsubmerged reed in the Changjiang Estuary

The influence of density,foliage and stem flexibility on the roughness coefficients under unsubmerged conditions,such as Manning＇s n,is investigated experimentally.An instrumentation system has been developed for measuring the flow rate ranging from 0.1 to 0.3 L/s under the condition of different artificial foliated reeds.Based on the experimental results,the influence on the relationship between n with different density,foliage,flexibility and flow depth is discussed.It is found that the foliage and the density are the important factors affecting Manning＇s n.At a range of relatively low velocity and relatively large bending stiffness of stem,Manning＇s n is not influenced significanthy by the flexibility of stem.

Biomass accumulation and nutrient uptake of 16 riparian woody plant species in Northeast China

Our research focused on eutrophication control and species screening for riparian zone vegetation restoration in the upstream reach of the Hun River. We studied 16 hardwood plant species to investigate nutrient concentrations and nitrogen and phosphorus accumulations. After about 120 days of growth in pots, these 16 species varied in dry matter biomass, ranging from 15.13 to 637.16 g. Total nitrogen （TN） and total phosphorus （TP） concentrations and distribution in roots, stems and foliage differed both within and between tested species. Mean TN and TP accumulation ranged from 0.167 to 14.730 g per plant and from 0.016 to 1.20 g, respectively. All 16 species, but especially Lespedeza bicolor, Robinia pseudoacacia and Sorbaria sorbifolia had strong potential to remove TN and TP from soil and could be widely utilized for the restora- tion of destroyed riparian zones in northeast China.

The Influence of Foliage Plants on Psychological and Physiological Responses

This research aims to clarify the significance of incorporating visual stimulation, in the form of foliage plants, into office desktop spaces. The experiments were conducted in a thermal environment with a temperature range that was slightly uncomfortable. The indoor thermal environment evaluation index ETF was used to measure the effects that brain stimulation of foliage plants have on comprehensive thermal senses. We focus on visual stimulation with foliage plants, and quantitatively measure shifts in thermal senses that affect the body. Thermal environment conditions were established with air temperature in three stages (25℃, 28℃ and 31℃) and the atmosphere was kept homogeneous with wall surface temperature equal to air temperature. The visual stimulations consisted of seven types of office desk image: benjamin, pothos, oxycardium, baby tears, moss ball, cacti, and no plant. At around 27℃ to 29℃ ETF, improvements in thermal sensation, as measured by thermal sensation statements, were shown to have resulted from visual stimulation benefits. Also, at around 26℃ to 29℃ ETF, improvements in comfort were shown, due to visual stimulation benefits as well, in subjects’ comfortable-sensation statements. This benefit was significant when a foliage plant’s green coverage ratio came between 0.75% and 4.67%, the range which does not create an overwhelming feeling from the foliage plant.

Accumulation of REEs in Field Wheat and Comparison between Two Kinds of REEs Dressing Methods

Four groups of field experiments including REEs foliage dressing, soil dressing, triple amounts of soil dressing and control were carried out. Contents of REEs in wheat in different growing stages were measured by ICP-MS. The results show that REEs amount in leaves increases significantly with foliage dressing in jointing stage, in addition to REEs accumulation with soil dressing method in jointing stage. Either using foliage dressing or soil dressing, there is no significant accumulation in mature stage. Comparison of the two methods shows that lower amount of REEs with foliage dressing can be highly absorbed in jointing stage.

Growth and chemical composition of silver birch:Comparative study between Lithuania and Romania

The effects of different climatic conditions on growth and chemical composition of Betula pendula in geographically different European regions,Lithuania and Romania,were compared.Birch species in the entire area have a wide natural distribution,but B.pendula is commercially more important in Lithuania than in Romania.Here we evaluated tree ring width,wood density and foliar chemical composition of mature birch trees in two European regions.Trees at the Lithuanian sites had greater radial growth and wood density with no clear changes in foliar chemistry than those at the Romanian sites.Mean wood density was 600-700 kg m^(-3) at Lithuanian and 350-450 kg m^(-3) at Romanian sites.Mean width of wood ring,earlywood and latewood for Lithuanian birch trees were several times higher than the means for Romanian birch trees.We hypothesized that the main differences in birch radial growth and wood density were due to the different climatic conditions in the studied regions.Ca,K and Mg concentrations were significantly higher and Fe and Mn were lower in the birch foliage at the Lithuanian sites compared those at the Romanian sites.Overall assessment of growth showed that silver birch cultivation is more appropriate for colder climate regions and that birch growth may change in the context of a warming climate.

Effects of simulated acid rain on the injury and physiological responses of crops

Experiment was performed to determine the injury and physiological responses of plantfoliage to simulated acid rain. Cross section of injured leaves, PH value of foliar homogenate,electrolyte leakage, malondialdehyde content, content of peroxidase and some other enzymes were exa-nilned after exposure to simulated acid rain. Plants exhibited visible leaf injury when exposed tosimulated acid rain at PH values of 2.5 and 3.0. Peroxidase content and isozyme bands increasedsignificantly after the treatment at PH 3.0. Injured plants had higher electrolyte leakage and higherlevels of malondialdehyde. This showed that simulated acid rain induced lipid peroxidation andmembrane damage.

The effect of growth conditions on the relationship between fine root and foliage biomass

This article examines the physiological relationships between fine roots and foliage, and how their biomass ratio correlates with changes in stand quality class. The biomass of fine roots ≤ 3 mm in diameter of spruce stands in the Republic of Karelia (Northwest Russia) was determined by the soil monolith method. Foliage biomass was calculated using a previously designed technique from the standing stock, average height and quality class of the stand. A relation between fine-root: foliage biomass ratio and stand quality class (representing soil fertility) has been established. The closest correlation between fine-root: foliage biomass ratio and stand quality based on soil fertility was for the 1-2 mm root fraction. Analysis of the water flux balance in the trees revealed a correlation between fine-root: foliage ratio and the ratio of the specific volume of transpiration by the stand to the specific volume of water uptake from the soil by roots. Theoretical explanations for the decrease in fine-root: foliage biomass ratios with increasing stand quality class are offered.

Improving precision of field inventory estimation of aboveground biomass through an alternative view on plot biomass

We contrast a new continuous approach(CA)for estimating plot-level above-ground biomass(AGB)in forest inventories with the current approach of estimating AGB exclusively from the tree-level AGB predicted for each tree in a plot,henceforth called DA(discrete approach).With the CA,the AGB in a forest is modelled as a continuous surface and the AGB estimate for a fixed-area plot is computed as the integral of the AGB surface taken over the plot area.Hence with the CA,the portion of the biomass of in-plot trees that extends across the plot perimeter is ignored while the biomass from trees outside of the plot reaching inside the plot is added.We use a sampling simulation with data from a fully mapped two hectare area to illustrate that important differences in plot-level AGB estimates can emerge.Ideally CA-based estimates of mean AGB should be less variable than those derived from the DA.If realized,this difference translates to a higher precision from field sampling,or a lower required sample size.In our case study with a target precision of 5%(i.e.relative standard error of the estimated mean AGB),the CA required a 27.1%lower sample size for small plots of 100 m2 and a 10.4%lower sample size for larger plots of 1700 m2.We examined sampling induced errors only and did not yet consider model errors.We discuss practical issues in implementing the CA in field inventories and the potential in applications that model biomass with remote sensing data.The CA is a variation on a plot design for above-ground forest biomass;as such it can be applied in combination with any forest inventory sampling design.

A model of seasonal foliage dynamics of the subtropical mangrove species Rhizophora stylosa Griff.growing at the northern limit of its distribution

Background： Progress of forest production in response to the environment requires a quantitative understanding of leaf area development. Therefore, it is necessary to investigate the dynamics of seasonal crown foliage in order to understand the productivity of mangroves, which play an important role in the subtropical and tropical coastlines of the world. Method： Crown foliage dynamics of the mangrove Rhizophora styloso were studies to reveal patterns of leaf recruitment, survival and seasonal leaf area growth. Results： Flushing of leaves occurred throughout the year, but both flushing and leaf area growth pattern of leaves varied with season. Maximum flushing occurred in summer, but leaf areas did not differ significantly with season. The half-expansion period is longer, and the intrinsic rate of increase was lower in winter. Summer flushed leaves grew faster at their initial stage and reached their maximum area over a shorter period of time. The difference in temperature and air vapor pressure deficit （VPD） between summer and winter contributed to the present dynamics of foliage patterns. The mean leaf longevity was estimated to be 13.1 month. The crown foliage area was almost stable throughout the year. Conclusions： Homeostatic control of the crown foliage area may be accompanied by the existence of ecophysiological mechanisms in R. stylosa. Integrating crown foliage dynamics into forest models represents an important step towards incorporating physiological mechanisms into the models for predicting growth responses to environmental changes and for understanding the complex responses of tree growth and litter production.

Early Nutrient Diagnosis of Kentucky Bluegrass Combining Machine Learning and Compositional Methods

Kentucky bluegrass (Poa pratensis L.) is the most common perennial turfgrass species grown on playgrounds, municipal and residential lawn areas, and golf tees, fairways and roughs. Fertilization is the most efficient way to improve and maintain turfgrass aesthetic quality. Tissue diagnosis can guide fertilization, but tissue concentration ranges are biased by not taking into consideration nutrient inter-relationships, carryover effects and other key features. The centered log-ratio transformation reflects nutrient interactions in plants and avoids statistical biases. Machine learning (ML) models relate the target variable to the key features ex ante, and can predict future events from prior knowledge. The objective of his study was to predict turfgrass quality from key features and rank nutrients in the order of their limitations. The experimental setup comprised four N, three P, and four K rates applied on permanent plots during three consecutive years. Soils were a loam and an USGA sand. Eleven elements (N, S, P, K, Ca, Mg, B, Cu, Zn, Mn, Fe) were quantified in clippings collected during spring, summer and autumn every year. Turfgrass quality was categorized as target variable by color rating. Concentrations were centered log-ratioed (clr) partitioned into four quadrants in the confusion matrix generated by the xgboost ML model. The area under curve (AUC) and model accuracy were high to predict turfgrass color from the nutrient analyses of clippings collected in the preceding season, facilitating the seasonal adjustment of the fertilization regime to sustain high turfgrass quality. We provide a computational example to run the ML model and rank nutrients in the order of their limitations.

Investigating the Effect of Weather and Seasonal Factors on Root Stability Using Dynamic Measurements

The dynamic tree stability assessment technique allows trees to be measured efficiently, under realistic weather conditions. In this study, the stability of four trees, including two conifers and two broad-leaved species was assessed in the Botanical Gardens of the University of Sopron, Hungary. The examined trees included Horse chestnut, Japanese zelkova, Douglas fir and Giant sequoia. Each tree was measured in various weather and seasonal conditions. Results show that the seasons affected the stability of broadleaved trees significantly, due to considerable changes in the crown surface area, while this difference was much lower in softwoods. Rainy weather loosens the topsoil, which adversely affects the stability of trees with relatively shallow roots. Lower layers take longer to saturate, and therefore trees with very deep roots are usually unaffected by the looser topsoil, while the increased weight of the top layer compacts the lower layers and improves stability, as evidenced by results measured on Sequoia. Snow accumulation on the branches increases the inertia of the tree, which imposes higher torque on the root collar, decreasing stability. In the meantime, the increased resistance offered by frozen ground stabilizes the tree, which more-or-less counterbalances this effect. A more extensive database of tree stability under different conditions is being built to allow for more comprehensive analysis of various factors, like wind direction, tree health and morphology, shading, etc.

Variability in total antioxidant capacity, antioxidant leaf pigments and foliage yield of vegetable amaranth

Twenty vegetable amaranth genotypes were evaluated for total antioxidant capacity, antioxidant leaf pigments, vitamins, and selection of suitable genotypes for extraction of juice in a randomized complete block design（RCBD） with three replications. Vegetable amaranth was rich in chlorophyll, β-cyanins, β-xanthins, betalains, carotene, ascorbic acid and total antioxidant. The genotypes VA14, VA16, VA18, VA15, and VA20 could be selected as amaranth vegtable varieties with high yields and abundance antioxidant leaf pigments and vitamins to produce juice. The genotypes VA13 and VA19 had above-average foliage yield and high antioxidant profiles while the genotypes VA2, VA3, VA9, VA11, VA12, and VA17 had a high antioxidant profiles and below-average foliage yield. These genotypes could be used as a donor parent for integration of potential high antioxidant profiles genes into other genotypes. The correlation study revealed a strong positive association among all the antioxidant leaf pigments, total antioxidant capacity and foliage yield. Selection based on total antioxidant capacity, antioxidant leaf pigments could economically viable to improve the yield potential of vegetable amaranth genotypes. Total carotene and ascorbic acid exhibited insignificant genotypic correlation with all the traits except total antioxidant capacity. This indicates that selection for antioxidant vitamins might be possible without compromising yield loss.

Essential oil yield and composition of four annual plants(ajowan,dill,moldavian balm and black cumin)under saline irrigation

Background:Ajowan,dill,moldavian balm and black cumin are annual medicinal plants,essential oil bearing that are cultivated in different parts of the world.Methods:A field experiment was conducted to assess the essential oil of ajowan,dill,moldavian balm and black cumin under salinity of 0.3,3,6 and 9 dS/m NaCl.Essential oils were obtained by using a Clevenger apparatus and their constituents were identified by GC and GC/MS.Results:Results showed that essential oil yield varied in tested plants under salt stress,but its changes did not follow a specific trend.Thymol was the most abundant constituent of ajowan seed essential oil,while thymol,γ-terpinene and p-cymene were the major constituents of the foliage essential oil of it.The most important component of dill seed essential oil was carvone and three main components of foliage essential oil were carvone,limonene andα-phellandrene.The essential oil component in moldavian balm mostly contained neral,geranial,geraniol,neryl acetate and geranyl acetate.The essential oil of black cumin was mainly composed of p-cymene under saline irrigation.Conclusion:The essential oil yield and compositions were affected by salt stress.The essential oil yield decreased because of decreasing dry biomass production.

Could gingko foliage serve as a bio-monitor for organochlorine pesticides in air?

The feasibility of gingko (Gingo Biloba) foliage as a passive bio-monitor for organochlorine pesticides in air was explored. The accumulation patterns of hexachlorocyclohexanes (HCHs), dichlorodiphenyl- trichloroethanes (DDTs) and hexachlorobenzene (HCB) in gingko foliage were similar; the amounts of HCHs, DDTs and HCB increased with foliage growth in spring and decreased thereafter. This accumu-lation pattern is likely related to the growing process of the gingko foliage, which was observed for the first time in our work, giving a piece of evidence for the "bud burst effect" in plants. Compared with those in pine needles in 1980's, the residual levels of HCHs and DDTs have declined obviously in Bei-jing, indicating that the ban on the production and use of organochlorine pesticides (OCPs) in our country is effective; however, the amount of HCB has increased, indicating great progress of chemical industry in Beijing. The analysis for the source of OCPs in the gingko foliage showed that the technical HCHs and DDTs were used largely in history, but were not used in recent years. A little lidane has been used and there was a new input of o,p′-DDT in recent years; dicofol usage may be the main source of o,p′-DDT. Concentrations of HCHs, DDTs and HCB in gingko foliages were similar to those in pine nee-dles in the corresponding period and there is a strong positive correlation between the OCPs concen-tration data obtained from these two kinds of trees. It presents no difference in the accumulation style between these two kinds of trees. The level of OCPs in the gingko foliage reflects the pollution status of OCP in air. The result of this work shows that the gingko foliage can be used as a bio-monitor of OCPs in air.

Effects of Dynamic Vegetation on Global Climate Simulation Using the NCEP GFS and SSiB4/TRIFFID

Two global experiments were carried out to investigate the effects of dynamic vegetation processes on numerical climate simulations from 1948 to 2008.The NCEP Global Forecast System(GFS)was coupled with a biophysical model,the Simplified Simple Biosphere Model(SSi B)version 2(GFS/SSi B2),and it was also coupled with a biophysical and dynamic vegetation model,SSi B version 4/Top-down Representation of Interactive Foliage and Flora Including Dynamics(TRIFFID)(GFS/SSi B4/TRIFFID).The effects of dynamic vegetation processes on the simulation of precipitation,near-surface temperature,and the surface energy budget were identified on monthly and annual scales by assessing the GFS/SSi B4/TRIFFID and GFS/SSi B2 results against the satellite-derived leaf area index(LAI)and albedo and the observed land surface temperature and precipitation.The results show that compared with the GFS/SSiB2 model,the temporal correlation coefficients between the globally averaged monthly simulated LAI and the Global Inventory Monitoring and Modeling System(GIMMS)/Global Land Surface Satellite(GLASS)LAI in the GFS/SSi B4/TRIFFID simulation increased from 0.31/0.29(SSiB2)to 0.47/0.46(SSiB4).The correlation coefficients between the simulated and observed monthly mean near-surface air temperature increased from 0.50(Africa),0.35(Southeast Asia),and 0.39(South America)to 0.56,0.41,and 0.44,respectively.The correlation coefficients between the simulated and observed monthly mean precipitation increased from 0.19(Africa),0.22(South Asia),and 0.22(East Asia)to 0.25,0.27,and 0.28,respectively.The greatest improvement occurred over arid and semiarid areas.The spatiotemporal variability and changes in vegetation and ground surface albedo modeled by the GFS with a dynamic vegetation model were more consistent with the observations.The dynamic vegetation processes contributed to the surface energy and water balance and in turn,improved the annual variations in the simulated regional temperature and precipitation.The dynamic vegetation processes had the greatest influence on the spatiotemporal changes in the latent heat flux.This study shows that dynamic vegetation processes in earth system models significantly improve simulations of the climate mean status.