Foliar Production Research Articles

The impact of insect herbivory on biogeochemical cycling in broadleaved forests varies with temperature

Herbivorous insects alter biogeochemical cycling within forests, but the magnitude of these impacts, their global variation, and drivers of this variation remain poorly understood. To address this knowledge gap and help improve biogeochemical models, we established a global network of 74 plots within 40 mature, undisturbed broadleaved forests. We analyzed freshly senesced and green leaves for carbon, nitrogen, phosphorus and silica concentrations, foliar production and herbivory, and stand-level nutrient fluxes. We show more nutrient release by insect herbivores at non-outbreak levels in tropical forests than temperate and boreal forests, that these fluxes increase strongly with mean annual temperature, and that they exceed atmospheric deposition inputs in some localities. Thus, background levels of insect herbivory are sufficiently large to both alter ecosystem element cycling and influence terrestrial carbon cycling. Further, climate can affect interactions between natural populations of plants and herbivores with important consequences for global biogeochemical cycles across broadleaved forests.

Tree variability limits the detection of nutrient treatment effects on sap flux density in a northern hardwood forest.

The influence of nutrient availability on transpiration is not well understood, in spite of the importance of transpiration to forest water budgets. Soil nutrients have the potential to affect tree water use through indirect effects on leaf area or stomatal conductance. For example, following addition of calcium silicate to a watershed at Hubbard Brook, in New Hampshire, streamflow was reduced for 3 years, which was attributed to a 25% increase in evapotranspiration associated with increased foliar production. The first objective of this study was to quantify the effect of nutrient availability on sap flux density in a nitrogen, phosphorus, and calcium addition experiment in New Hampshire in which tree diameter growth, foliar chemistry, and soil nutrient availability had responded to treatments. We measured sap flux density in American beech (Fagus grandifolia, Ehr.), red maple (Acer rubrum L.), sugar maple (Acer saccharum Marsh.), white birch (Betula papyrifera Marsh.), or yellow birch (Betula alleghaniensis Britton.) trees, over five years of experiments in five stands distributed across three sites. In 2018, 3 years after a calcium silicate addition, sap flux density averaged 36% higher in trees in the treatment than the control plot, but this effect was not very significant (p = 0.07). Our second objective was to determine whether this failure to detect effects with greater statistical confidence was due to small effect sizes or high variability among trees. We found that tree-to-tree variability was high, with coefficients of variation averaging 39% within treatment plots. Depending on the species and year of the study, the minimum difference in sap flux density detectable with our observed variability ranged from 46% to 352%, for a simple ANOVA. We analyzed other studies reported in the literature that compared tree water use among species or treatments and found detectable differences ranging from 16% to 78%. Future sap flux density studies could benefit from power analyses to guide sampling intensity. Including pretreatment data, in the case of manipulative studies, would also increase statistical power.

Effects of Elevated Atmospheric CO2 Concentration on Insect Herbivory and Nutrient Fluxes in a Mature Temperate Forest

Insect herbivory is one of the most important ecological processes affecting plant–soil feedbacks and overall forest ecosystem health. In this study, we assess how elevated carbon dioxide (eCO2) impacts (i) leaf level insect herbivory and (ii) the stand-level herbivore-mediated transfer of carbon (C) and nitrogen (N) from the canopy to the ground in a natural mature oak temperate forest community in central England at the Birmingham Institute of Forest Research Free Air CO2 Enrichment (BIFoR FACE) site. Recently abscised leaves were collected every two weeks through the growing season in August to December from 2017–2019, with the identification of four dominant species: Quercus robur (pedunculate oak), Acer pseudoplatanus (sycamore), Crataegus monogyna (common hawthorn) and Corylus avellana (hazel). The selected leaves were scanned and visually analyzed to quantify the leaf area loss from folivory monthly. Additionally, the herbivore-mediated transfer of C and N fluxes from the dominant tree species Q. robur was calculated from these leaf-level folivory estimates, the total foliar production and the foliar C and N contents. This study finds that the leaf-level herbivory at the BIFoR FACE has not changed significantly across the first 3 years of eCO2 treatment when assessed across all dominant tree species, although we detected significant changes under the eCO2 treatment for individual tree species and years. Despite the lack of any strong leaf-level herbivory response, the estimated stand-level foliar C and N transferred to the ground via herbivory was substantially higher under eCO2, mainly because there was a ~50% increase in the foliar production of Q. robur under eCO2. This result cautions against concluding much from either the presence or absence of leaf-level herbivory responses to any environmental effect, because their actual ecosystem effects are filtered through so many (usually unmeasured) factors.

The Combination of Compost Derived Poultry Litter and Vivianite Powder: Appropriate Biological Fertilizer to Improve the Growth and Root Yield of Daucus carota L

This study aims to improve the growth potential of carrot in the Northern Cameroon while limiting the use of chemical inputs. The experiment was conducted under field conditions at Maroua and Ngaoundere, respectively in the agro-ecological zone I and II, and during the two consecutive cropping seasons of 2019 and 2020. Results indicate that carrot root growth and production varied depending on fertilizer, agroecological zone and the year of experimentation. Globally, treated plant by the combination of 1 Kg of poultry litter with 10 g of vivianite powder (F1+P10) exhibited significantly (p<0.05) the highest growth (plant height, number of leaves per plant) and production parameters (root lenght, root diameter, root dry biomass, root yield). F1+P10 fertilizer increased the foliar production at 60% and 69%, compared to no treated plants in Ngaoundere and Maroua rspectively. This fertilizer increased the root yield at 2% and 41% compared to T+ in Ngaoundere and Maroua respectively in 2019, and at 26% and 68% compared to no treated plants respectively in 2020. The application of the combination of 1 kg of poultry litter and 10 g of vivianite powder per hole at sowing for carrot growth would contribute to improve this root vegetable, to valorize our local material in agriculture while ensuring sustainable agriculture. However, the effect of this natural fertilizer on the nutritional values of carrot needs to be assessed.

Performance supplementation and ingestive behavior of sheep finished in continuous pasture in the period of water restriction

The objective was to evaluate the performance and ingestive behavior of grazing sheep in the finishing stage, with supplementation in the period of water restriction. Fifteen male crossbred sheep were used in continuous pasture in Massai grass and supplied supplement formulated with 18% of crude protein in three levels (0.0; 0.3 and 0.6% of body weight), individually. Bromatological and fodder production analyses were performed, as well as foliar mass production, stem mass and senescent material mass. The performance and ingestive behavior of the animals were evaluated. The design was in four randomized blocks for the variables measured in the fodder. For the biometry, weight gain and behavior variables measured in the animals, the design was entirely randomized with five repetitions. The total forage mass production was 5512.41 kg ha-1, with 6.58% of crude protein, 79 38% of neutral detergent fiber and with 65% of foliar mass. The total weight gain and daily weight gain were higher in animals that received a supplement of 0.6% of body weight. In general, the animals grazed more in the morning period and the supplemented ones destined more time for rumination and leisure than the ones not supplemented.

The role of seed size in the performance of Ceiba aesculifolia seedlings subjected to foliar damage

In tropical forests, herbivore damage is one of the main causes of seedling mortality. However, along with seed size, the resources herbivores provide are an important factor in a seedling's response to selection pressure. The objective of this study was to evaluate the role of seed size and artificially-induced herbivory on the functional traits of Ceiba aesculifolia seedlings. To do this, we established four levels of foliar damage: 10%, 25%, 50%, and 75% (n = 270), and a control treatment (no damage; n = 60). Foliar damage treatments were conducted 60 days after germination. These treatments were applied to seedlings developing from seeds of three different sizes. The response variables were growth, some foliar traits, and seedling biomass. Seedlings from small seeds showed higher growth rates in terms of height (0.44 ± 0.02 cm month−1), diameter (0.24 ± 0.01 mm month−1), and foliar production (9.1 ± 0.19 leaves), as well as higher total dry weight (8.5 ± 0.03 g) and larger leaf area (49.3 ± 1.9 cm2) than those from medium and large seeds. Seedlings from large and medium seeds showed higher root:stem ratio values than seedlings from small seeds (p < 0.05). Foliar damage was found to have an effect on dry weight. The total biomass of seedlings with 75% damage was considerably smaller than that of seedlings with 10% damage. Chlorophyll content was found to be related to the interaction between seed size and foliar damage, and it was lower in seedlings from medium seeds and 50% damage than in those from small seeds with the same level of damage and large seeds with 75% damage. In short, seed size had a significant effect on growth traits. Contrary to our expectations, seedlings from small seeds showed the best performance in terms of height, biomass, number of leaves, and foliar area.

Ecotypic differentiation of a circumpolar Arctic-alpine species at mid-latitudes: variations in the ploidy level and reproductive system of Vaccinium vitis-idaea.

Although plant species originated from Arctic regions commonly grow in alpine habitats at mid-latitudes, some populations of these species exist also in some specific habitats below the treeline. Local populations at lower elevations may have different origins, ploidy levels, mating systems and/or morphological traits from alpine populations, but comparative studies between alpine and low-elevation populations are scarce. We aimed to reveal the ecological and genetic differentiations between higher and lower populations of Vaccinium vitis-idaea in Hokkaido, northern Japan by comparing 22 populations growing in diverse environments. We analysed the ploidy level of individual populations using flow cytometry. Genetic differentiation among populations, and genetic diversity within populations were calculated using microsatellite markers. Fruit and seed production were recorded under natural conditions, and a pollination experiment was conducted to reveal the variations in mating system across populations. Furthermore, we compared shoot growth and leaf characteristics among populations. Most of the low-elevation populations were tetraploid, whereas all but one of the alpine populations were diploid. Tetraploid populations were clearly differentiated from diploid populations. Some tetraploid populations formed huge clonal patches but genetic diversity was higher in tetraploids than in diploids. Alpine diploids were self-incompatible and produced more seeds per fruit than tetraploid populations. In contrast, tetraploids showed high self-compatibility. Leaf size and foliar production were greater in tetraploid populations. Our results indicate that the genetic compositions of low-elevation tetraploid populations are different from those of alpine diploid populations. Most populations at lower elevations contained unique ecotypes suited to persistence in isolated situations. Local, low-elevation populations of typical alpine species maintain ecologically and genetically specific characteristics and could be valuable in terms of evolutionary and conservation biology. The present study demonstrates the biological importance of small and isolated populations at the edges of species distribution.

Use of arbuscular mycorrhizal fungi and phosphorus for increase in the concentration of compounds with antioxidant activity in Libidibia ferrea

The increase of the concentration of secondary compounds in medicinal plants can be influenced by the association with arbuscular mycorrhizal fungi (AMF). Pharmacological studies have shown that secondary compounds, found ing Libidibia ferrea (Mart. ex Tul.) L. P. Queiroz, confer phytotherapeutic potential to the species due to antidiabetic, antibiotic and anticancer activity. Therefore, the aim of this work was to verify if the presence of AMF associated or not with phosphate fertilization has an effect on the concentration of foliar phenolic compounds with antioxidant activity in L. ferrea seedlings. The seedlings were transferred to pots with 1.2 kg of soil with phosphate fertilization (P2O5) or not. In the roots was deposited soil-inoculum, containing 300 spores {100 spores of each AMF species: Claroideoglomus etunicatum, Gigaspora albida and Acaulospora longula Acaulospora longula. The plants were maintained in greenhouse for seven months. AMF favored an increase in shoot dry matter production, accumulation of flavonoids and greater total antioxidant activity, dispensing fertilization of the soil. The mycorrhizal inoculation associated with phosphate fertilization maximized the biosynthesis of total chlorophyll and soluble carbohydrates. AMF inoculation presents as a possible biotechnological alternative to increase antioxidant activity and foliar flavonoid production in L. ferrea seedlings, avoiding expenses with agricultural inputs, such as phosphate fertilization, making phytomass more attractive for the production of phytotherapics.

Winter cover crops as reservoirs of tobacco rattle virus (TRV) and hosts of root-lesion, root knot and stubby-root nematodes

A greenhouse pot study was conducted on four cover crops (annual ryegrass, perennial tetraploid ryegrass, winter wheat cv. ‘Caledonia’ and sorghum-sudangrass) and one rotation crop (sweet corn cv. ‘Sheba’) to compare the efficiency of these crop species as hosts of Paratrichodorus minor (Colbran) Siddiqi, and the ability of the nematodes to acquire tobacco rattle virus (TRV) from roots of infected plants and re-transmit it to healthy plants. P. minor reproduced rapidly on sorghum-sudangrass and sweet corn and re-transmitted the virus to indicator plants. Annual ryegrass, perennial ryegrass, and winter wheat cv. ‘Caledonia’, all of which re-transmitted TRV poorly in the greenhouse, were evaluated in two years of field studies for fall establishment and soil coverage, nutrient sequestration, effect on parasitic nematode populations and on subsequent potato crops. Annual ryegrass performed best overall in terms of establishment, ground cover, overwintering survival and foliar biomass production. None of the cover crops had a consistently significant effect on populations of parasitic nematodes in field plots, including Pratylenchus, Paratrichodorus, and Meloidogyne. Both ryegrass cover crops appeared to provide a favourable environment for survival of root knot nematodes (Meloidogyne spp.), although they are not considered to be hosts of this nematode. There was no difference in soil carbon, nitrogen or potato yield following any cover crop. Symptoms of corky ringspot were not observed in the field and TRV was not detected in potato plants by RT-PCR.

The Combination of Arbuscular Mycorrhizal Fungi with Rock Powder and Poultry Litter: An Appropriate Natural Fertiliser for Improving the Productivity of Soybean (Glycine max (L.) Merr)

Abstract The present study aimed to evaluate the effect of the combination of various natural fertilisers on growth and seed yield of the soybean plants. Field experimentations were carried out during two cropping seasons (2018 and 2019). A randomized complete block experimental design with 11 treatments (F1: 30 g of poultry litter, F2: 60 g of poultry litter, MP: 10 g of mycorrhizae + 10 g of vivianite powder, MF1: 10 g of mycorrhizae + 30 g of poultry litter, MF2: 10 g of mycorrhizae + 60 g of poultry litter, PF1: 10 g of vivianite powder + 30 g of poultry litter, PF2: 10 g of vivianite powder + 60 g of poultry litter, MPF1: 10 g of mycorhizae + 10 g of vivianite powder + 30 g of poultry litter, MPF2: 10 g of mycorrhizae + 10 g of vivianite powder + 60 g of poultry litter, T+: chemical fertiliser, T–: unfertilised plants) and three replications were used. The growth parameters and seed yield were evaluated. The results showed that the growth and seed yield of soybean varied depending on the fertiliser and the cropping season. Plants that have received the MPF2 treatment exhibited significantly (p ˂ 0.05) the highest values of the studied parameters (plants height, foliar production, plants dry biomass, seed yield). The MPF2 treatment increased the seed yield of soybean by 20.08% and 184.76% compared to T+ and T– treatments, respectively. The supply of the following combination, 10 g of mycorrhizae + 10 g of vivianite powder + 60 g of poultry litter was found to be very promising in improving the soybean plant growth and therefore, can be used as an alternative to replacing the mineral fertilisers usually employed for the cultivation of this crop.

The role of seed size in the emergence and survival of seedlings in contrasting environments: the case of Ceiba aesculifolia

In the tropical low deciduous forest, seed size has been recognized as a functional trait that can contribute to the development of restoration strategies due to its influence on the processes of germination, survival and growth of seedlings. The objective of this study was to evaluate the effect of seed size on the seedling emergence and establishment of seedlings of Ceiba aesculifolia in pastures and remnants of tropical low deciduous forest in central Veracruz, Mexico. Three seed sizes were evaluated: small (120–218 mg), medium (219–316 mg) and large (317–414 mg). Seedling emergence rate was estimated, height, foliar production, stem thickness and insect herbivory were measured monthly in the seedlings. Seedling emergence differed significantly among seed sizes. The large seeds emerged at 40% in the pastures and 24% in the forest remnants, while the medium seeds presented 20 and 27% in these sites, respectively. The small seeds emerged similarly in the pasture (33%) and forest remnant (28%) sites. In the pastures, regardless of seed size, the seedlings presented significantly higher growth rates and foliar production, as well as an increase in the percentage of herbivory. At the end of the study, there was no difference in seedling survival between seed sizes or sites. The results suggest that the seed size only influences the seedling emergence, while the growth and responses to herbivory depend on their functional traits to face the environmental conditions of the sites. Finally, the ecological and management implications for future restoration programs are discussed.

Trade-offs Between Wood and Leaf Production in Arctic Shrubs Along a Temperature and Moisture Gradient in West Greenland

Warming environmental conditions are often credited with increasing Arctic shrub growth and altering abundance and distribution, yet it is unclear whether tundra shrub expansion will continue into future decades. Water availability may begin to limit Arctic shrub growth if increasing air temperatures create drier soil conditions due to increased evapotranspiration and permafrost-thaw-induced soil drainage. However, few studies have effectively considered how dominant tundra shrub species respond to variations in both temperature and moisture. To better understand the key effects of temperature variation and soil moisture on two dominant circumpolar deciduous shrubs, we studied shrub growth along a natural landscape gradient in West Greenland, which is a region observed to be drying due to ongoing warming. We found that the growth forms of both grey willow (Salix glauca) and dwarf birch (Betula nana) were sensitive to warmer and drier conditions. For both species, increases in air temperature positively correlated with greater shrub volume, with the doubling of canopy volume due to increased woody biomass. Leaf biomass was best predicted by edaphic features including extractable ammonium, which was positively related to soil moisture, and bulk density. Warmer soils tended to be drier, suggesting that ongoing warming in the area could lead to significant water limitation. Our findings suggest that drier soil conditions might be limiting foliar production despite warming temperatures for two circumpolar dominant shrubs, Betula nana and Salix glauca, which could have wide-ranging, biome-level consequences about ongoing and predicted shrub growth and expansion.

Compost Derived from Sugar Cane Processing Waste Better Improves Baillonella toxisperma P. Growth in Nkoteng-Cameroon Locality

Aims: Baillonella toxisperma P. (moabi) is a woody which belongs to Sapotaceae family. It is endemic to the forests of Congo Basin, and therefore to Cameroonian forests. In Cameroon, B. toxiperma undergoes anthropogenic pressure which may lead to its complete disappearance. In this respect, the establishment of an appropriate technical route for regeneration of this species, which becomes rare because of overexploitation, is a necessity. This study aimed to improve the regeneration of moabi while contributing to sustainable agriculture.&#x0D; Study Design: A random device design with 5 treatments (control, compost derived sugar cane processing waste, bagasse, molasses and bagasse-molasses mixture) was used.&#x0D; Place and Duration of Study: Under Bimodal Forest climate in the Central Cameroon region, between September, 2018 and April 2019.&#x0D; Methodology: The breaking of moabi seeds dormancy, physico-chemical properties of soil and produced compost, and growth parameters (plant height, foliar production, diameter of stem, and dry biomass of plant) were evaluated to determine the development of the seedlings.&#x0D; Results: Moabi seeds stored cold at 4°C for 48 hours before sowing germinated better. Compost significantly (p˂0.001) increased moabi plants growth compared to bagasse, molasses, bagasse-molasses mixture. Dry biomass of treated moabi plants by compost, bagasse, bagasse-molasses mixture and molasses were 1.80; 1.13; 1.78; 1.40 fold greater than those of unfertilized plants respectively.&#x0D; Conclusion: The use of sugar cane compounds works as a double benefit because in addition to using compounds previously discarded, we are adding potent fertilizers that act strongly on moabi growth.

The biosynthesis of pharmacologically active compounds in Calophyllum brasiliense seedlings is influenced by calcium and potassium under hydroponic conditions

Background: The influence of soil nutrients on biosynthesis of secondary metabolites from tropical trees has been poorly investigated.Questions: Does the deprival of Ca2+ and K+ influence the production of pharmacologically active compounds in the seedling of Calophyllum brasiliense ?Species study: Calophyllum brasiliense Cambess.Study site: Los Tuxtlas, Veracruz, Mexico; November 2005 to November 2009.Methods: The seedlings were obtained from seeds and subjected to different hydroponic treatments: 1) modified Hoagland solution (MHS), 2) MHS-Ca2+, and 3) MHS-K+. Growth, height, foliar biomass, and HPLC analysis were performed after 7 months.Results: Under hydroponic conditions Ca2+ and K+ deficiency induced the mortality of 53 % and 28 % of the seedlings, respectively. The foliar biomass, and plant height of the survivors were also drastically reduced. MHS-K+ treatment induced a 15, 4.2 and 4.3-fold decrease for calanolides B, C, and apetalic acid in the leaves, respectively. MHS-Ca2+ treatment induced a decrease of 4.3, and 2.4-fold for calanolide B, and C, respectively.Conclusion: Ca2+ is essential for survival of C. brasiliense seedlings under hydroponic conditions, Ca2+ and K+ are critical for growth, foliar production, and biosynthesis of apetalic acid, and calanolide B.

Long-term demography and stem productivity of Everglades mangrove forests (Florida, USA): Resistance to hurricane disturbance

Mangrove wetlands along coastal regions in neotropical northern latitudes are exposed to frequent hurricanes and therefore depend on resistant and resilient attributes to persist after these extreme events. However, few long-term studies have documented mangrove forest dynamics following hurricane disturbance to determine how species-specific phenotypic plasticity, species range shifts, and environmental stress interact to determine recovery trajectories. We present here a comprehensive analysis of Hurricane Wilma’s (hereafter, “Wilma”) impact (category 3, October 2005) on mangrove forest demography and aboveground net productivity in the Everglades, Florida (USA). We determined spatiotemporal patterns over a 15-year period (5 pre- and 10 post-Wilma) in three impacted sites on a productivity gradient along the Shark River Estuary. Hurricane resistance was evident in the low cumulative tree mortality and long-term recovery from defoliation (∼10 years). Aboveground standing carbon stocks were not significantly reduced, as mortality ranged only from 3 to 10%. A negative linear relationship between Leaf Net Primary Productivity (NPPL) and foliar residence time along the estuary shows that an increase in foliar production results in shorter residence time, which is defined by the interannual variation in NPPL rates and recovery periods across sites. We propose this relationship as a proxy of canopy recovery in latitudinal comparative studies across mangrove ecotypes and coastal settings. This work advances ecological disturbance theory and ecological modeling of mangrove forests; specifically, we provide quantitative relationships among structural properties and dynamic processes to validate agent-based demographic and biogeochemical models to forecast the impact of natural and human disturbances on mangrove wetlands under climate change.

WINTER BEAN PRODUCTIVITY UNDER UROCHLOA STRAW FERTILIZED WITH NITROGEN

ABSTRACT: An experiment was conducted during the years 2009 and 2010 to evaluate the effects of Urochloa forage straw and nitrogen fertilization on soil properties, nutritional foliar content, index of foliar chlorophyll (IFC) values, production components, and grains yields of winter bean (Phaseolus vulgaris 'Pérola') in the Cerrado lowlands region of Brazil. The treatments consisted of planting bean crops under straw of Urochloa brizantha 'Xaraés' and Urochloa ruziziensis, fertilized with urea-sourced N (0, 50, 100, 150, and 200 kg N ha-1). The experimental design was randomized blocks with four replications, and a factorial scheme of 2 × 5. The greater yield of U. brizantha dry matter in the two years of evaluation increased bean leaf nutrient levels. The nutritional increase with increasing N application rates showed that the straw produced by the forages had a positive effect on bean nutrition. The grain yield was satisfactory but was not affected by the forage species nor by changes in the N application rates. The Urochloa straw increased the soil organic matter (SOM), Ca, and Mg content in both evaluated years, affected the decomposition and mineralization of organic residues, and ensured the proper development of the bean plants.

Vermicompost and arbuscular mycorrhizal fungi: An alternative to increase foliar orientin and vitexin-2-O-ramnoside synthesis in Passiflora alata Curtis seedlings

Arbuscular mycorrhizal fungi (AMF) increase the synthesis of the secondary metabolites in Passiflora alata. However, there is no information about the role of AMF on glycosyl flavonoids metabolism. Flavonoids have neuropharmacological activity and are relevant for pharmaceutical industry. The hypothesis was that AMF improve foliar production of orientin and vitexin-2-O-ramonoside. The aim of this work was to determine the effects of mycorrhizal inoculation and vermicompost manuring, on the foliar concentration of vitexin-2-O-ramonoside and orientin in P. alata seedlings. In a greenhouse experiment, seedlings were inoculated with Gigaspora albida and cultivated with different levels of vermicompost (VC) (0, 0.05, 0.1, 0.15 and 0.2kgVCkg−1 soil). At the end of the experiment, total colonization was determined and foliar flavonoids concentration was quantified by liquid chromatography (HPLC). Mycorrhized seedlings, grown in soil with 0.15 and 0.2kgVCkg−1 soil synthesized more flavonoids. The mycorrhization increased foliar orientin concentration in 139.34%, in seedlings cultivated in soil with 0.2kgVCkg−1 soil. The inoculation of P. alata seedlings with G. albida promoted benefits on the orientin and vitexin-2-O-ramnoside synthesis, but responses vary according with soil fertility.

Urbanization effects on leaf litter decomposition, foliar nutrient dynamics and aboveground net primary productivity in the subtropics

Urbanization can alter nutrient cycling. This research evaluated how urbanization affected nutrient dynamics in the subtropics. We established 17–0.04 ha plots in five different land cover types—slash pine (Pinus elliottii) plantations (n = 3), rural natural pine forests (n = 3), rural natural oak forests (n = 4), urban pine forests (n = 3) and urban oak forests (n = 4) in the Florida panhandle, a subtropical region that has experienced rapid urbanization. On each plot, we measured the decomposition of mixed species foliar litter, the nutrient release patterns in decomposing litter, foliar litter quality, and forest floor temperatures. Aboveground net primary productivity and soil carbon and nitrogen contents were also measured to characterize the carbon and nitrogen stocks and fluxes in the urban and rural sites. Litter decay rates, liter quality indices and nutrient release patterns in decomposing litter did not differ among urban and rural forests despite differences in forest floor temperatures between urban and rural sites. Urban forest floor temperatures are on average warmer by 0.63 °C in the winter (p = 0.005) and tend to have a more narrow temperature range than those of the rural forested sites. Foliar mass was measured over an 82 week period that was characterized by drought, which may have masked an urbanization effect. Urban forest land covers had higher aboveground net primary productivity and foliar productivity compared to rural land covers. This increased input of foliar carbon is not reflected in statistically different forest floor or surface soil (0–7.5 cm) carbon contents between urban and rural sites. Understanding how drought interacts with other drivers of change in urban systems may be a necessary component of city specific ecological knowledge.

A Strain of &lt;i&gt;Chlorella &lt;/i&gt;sp&lt;i&gt;.&lt;/i&gt; was Used for Chicken Manure Fermentation Broth Treatment and Bio-Crude Oil Feedstock Production

One of the useful applications of chicken manure fermentation broth was foliar fertilization production. However, the effluent generated during foliar fertilization production processing was high in ammonia concentration, which was hard to be disposed by activated sludge method. Selecting microalgae to treat this kind of wastewater can realize pollutants purification, nutrients recovery and bio-energy production. A strain of Chlorella sp. was used. Results showed that the effluent can be used for microalgae cultivation. The optimal ammonia in the third (TS) and second step (SS) effluent for Chlorella sp. growth was around 500 mg/L and the net growth rate was 49.2 and 51.0 mg/L, respectively. The optimal addition amount of inorganic carbon was 228.6 mg/L for TS to cultivate Chlorella sp. By adding carbon resource every other day with trace elements, biomass reached to the highest value of 915.6 mg/L at 9 day. Without any addition of nutrient, the mixture of TS and SS can realize biomass accumulation of 497.0 mg/L. The highest removal of NH4+-N could reach 40%.

Impact of volcanic ash deposition on foliar productivity and insect herbivory in northern Patagonia deciduous forests

Volcanism has been a major force shaping the dynamics of Andean landscapes during the Holocene. Yet we still know little about the consequences of modern volcanic events on forest functioning. Ash fall may elicit multiple direct and indirect effects on key ecosystem attributes, with disturbance severity likely varying with distance to the crater. We examined the impact of ash deposition on foliage productivity and insect herbivory after the 2011 eruption of the Volcan Puyehue-Cordon Caulle system, in Nothofagus pumilio forests of northern Patagonia, Argentina. Tree leaf litterfall, a surrogate for annual foliar production, was measured before and after the event in wet and dry forest sites, which were located 22 km and 80 km east from the crater and were affected by mass deposition of coarse- and fine-grained tephra, respectively. Leaf damage by insects was monitored over a 10-year span (2004-2013) including the volcanic event. Foliar productivity in 2012 dropped by 60% in the wet forest, but did not change in the dry forest. Leaf area damaged by insects decreased abruptly in 2012, with post-eruption herbivory levels falling outside the range of annual variation recorded before the event. The impact was most severe in the dry forest wich normally supports the highest endemic herbivory. In contrast, leaf damage remained high in another dry forest located 98 km southeast from the crater and little affected by ashfall. Changes in foliar production and insect herbivory persisted for two years after the event. Our results show a widespread disruption of canopy-herbivore interactions in areas heavily affected by tephra. Remarkably, volcanic ash acted as a broad-spectrum insecticide on canopy herbivores. In the short-term, ashfall constrained the energy flow through the forest canopy and the arthropod consumer community, and thus temporarily overwhelmed previously existing differences in productivity and herbivory between wet and dry forest habitats. (Keywords: Canopy insects, disturbance, herbivory, long-term study, Nothofagus pumilio, productivity, volcanism)