Contrasting effects of elevated carbon dioxide concentration and temperature on Rubisco activity,chlorophyll fluorescence,needle ultrastructure and secondary metabolites in conifer seedlings

Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) seedlings were grown for 50 days in growth chambers in an ambient or twice ambient carbon dioxide concentration ([CO2]) at a day/night temperature of 19/12 degrees C or 23/16 degrees C. Although elevated [CO2] (EC) had only slight effects on the growth parameters measured, elevated temperature (ET) increased above ground dry mass of both species. Among treatments, biomass accumulation of both species was greatest in the combined EC + ET treatment. The EC treatment induced thylakoid swelling and increased numbers of plastoglobuli observed in Scots pine needles. Although EC had little effect on Rubisco protein or N concentration of needles, ET had a large effect on N-containing compounds and enhanced N allocation from 1-year-old needles. Terpenoids were more responsive to EC and ET than total phenolics. Generally, terpene concentrations were reduced by EC and increased by ET. Increased terpenoid concentrations in response to ET might be associated with thermotolerance of photosynthesis. In Norway spruce, EC decreased total phenolic concentrations in needles, probably as a result of increased growth. We conclude that, in seedlings of these boreal species, the effects of elevated [CO2] on the studied parameters were small compared with the effects of elevated temperature.     

Elevated atmospheric CO(2) affects the chemical quality of brassica plants and the growth rate of the specialist, Plutella xylostella, but not the generalist, Spodoptera littoralis

Cabbage, Brassica oleracea subsp. capitata (cv. Lennox and Rinda), and oilseed rape, Brassica rapa subsp. oleifera (cv. Valo and Tuli), plants were grown under ambient CO(2) (360 ppm) or elevated CO(2) (720 ppm) at 23/18 degrees C and under a photoperiod of 22/2 h light (250 micromol m(-)(2) s(-)(1))/dark regime for up to 5 weeks. Afterward, the performance of the crucifer specialist Plutella xylostella (Lepidoptera: Plutellidae) and the generalist Spodoptera littoralis (Lepidoptera: Noctuidae) on those plants was studied. The mean relative growth rate (RGR) of P. xylostella larvae, feeding on both cultivars of oilseed rape or on the Lennox cultivar of cabbage leaves grown at an elevated CO(2) concentration, was significantly reduced as compared to ambient CO(2). A negative larval growth rate at elevated CO(2) was observed for P. xylostella on both oilseed rape cultivars, but the growth rate was reduced but positive on cabbage. Conversely, the RGR of S. littoralis on either plant species was not affected by CO(2) treatment but was lower on cabbage cv. Rinda than on cv. Lennox. The mortality of the larvae was not affected by CO(2) treatment either. At the same time, elevated CO(2) significantly decreased the concentrations of leaf phytochemical constituents in oilseed rape, i.e., total phenolics and total nitrogen, but not in cabbage. The effect of elevated CO(2) on the leaf glucosinolate concentrations of both plant species was marginal. In addition, the observed significant changes in individual glucosinolate concentrations of oilseed rape leaves were not consistent among cultivars. However, our results demonstrate for the first time quite strong effects of CO(2) enrichment on the larval performance of P. xylostella, which is an important pest of Brassica plants around the world. Further studies are still required to increase our understanding of why elevated CO(2) differently affects the performance of specialist and generalist insect herbivores on Brassica plants.     

Influence of carrot psyllid (Trioza apicalis) feeding or exogenous limonene or methyl jasmonate treatment on composition of carrot (Daucus carota) leaf essential oil and headspace volatiles

The effect of carrot psyllid (Trioza apicalis F?rster) feeding and limonene and methyl jasmonate (MeJA) treatments on the essential oil composition and headspace volatiles of carrot (Daucus carota ssp. sativus), cvs. Parano and Splendid, leaves was studied. Carrot psyllid feeding significantly increased the concentrations of sabinene, beta-pinene, and limonene, whereas limonene treatment increased the concentration of (Z)-beta-ocimene in the leaves of both cultivars. The limonene treatment significantly increased the concentration of total phenolics in the leaves of both cultivars, and MeJA treatment increased phenolic concentration in the leaves of Parano. Exogenous limonene spray did not decrease the number of carrot psyllid eggs laid either 2 or 24 h after treatment. The results suggest that carrot psyllid feeding induces changes in the endogenous monoterpene pool in the carrot leaves. Limonene and MeJA treatments affect some induced defenses of the carrot, but the exogenous limonene spray is not an effective oviposition deterrent against carrot psyllid.     

Bioindication and modelling of atmospheric deposition in forests enable exposure and effect monitoring at high spatial density across scales

Key message

Moss surveys provide spatially dense data on environmental concentrations of heavy metals and nitrogen which, together with other biomonitoring and modelling data, can be used for indicating deposition to terrestrial ecosystems and related effects across time and areas of different spatial extension.

Context

For enhancing the spatial resolution of measuring and mapping atmospheric deposition by technical devices and by modelling, moss is used complementarily as bio-monitor.

Aims

This paper investigated whether nitrogen and heavy metal concentrations derived by biomonitoring of atmospheric deposition are statistically meaningful in terms of compliance with minimum sample size across several spatial levels (objective 1), whether this is also true in terms of geostatistical criteria such as spatial auto-correlation and, by this, estimated values for unsampled locations (objective 2) and whether moss indicates atmospheric deposition in a similar way as modelled deposition, tree foliage and natural surface soil at the European and country level, and whether they indicate site-specific variance due to canopy drip (objective 3).

Methods

Data from modelling and biomonitoring atmospheric deposition were statistically analysed by means of minimum sample size calculation, by geostatistics as well as by bivariate correlation analyses and by multivariate correlation analyses using the Classification and Regression Tree approach and the Random Forests method.

Results

It was found that the compliance of measurements with the minimum sample size varies by spatial scale and element measured. For unsampled locations, estimation could be derived. Statistically significant correlations between concentrations of heavy metals and nitrogen in moss and modelled atmospheric deposition, and concentrations in leaves, needles and soil were found. Significant influence of canopy drip on nitrogen concentration in moss was proven.

Conclusion

Moss surveys should complement modelled atmospheric deposition data as well as other biomonitoring approaches and offer a great potential for various terrestrial monitoring programmes dealing with exposure and effects.

     

Use of human urine fertilizer in cultivation of cabbage (Brassica oleracea)--impacts on chemical, microbial, and flavor quality

Human urine was used as a fertilizer in cabbage cultivation and compared with industrial fertilizer and nonfertilizer treatments. Urine achieved equal fertilizer value to industrial fertilizer when both were used at a dose of 180 kg N/ha. Growth, biomass, and levels of chloride were slightly higher in urine-fertilized cabbage than with industrial-fertilized cabbage but clearly differed from nonfertilized. Insect damage was lower in urine-fertilized than in industrial-fertilized plots but more extensive than in nonfertilized plots. Microbiological quality of urine-fertilized cabbage and sauerkraut made from the cabbage was similar to that in the other fertilized cabbages. Furthermore, the level of glucosinolates and the taste of sauerkrauts were similar in cabbages from all three fertilization treatments. Our results show that human urine could be used as a fertilizer for cabbage and does not pose any significant hygienic threats or leave any distinctive flavor in food products.     

Chemical changes induced by methyl jasmonate in oilseed rape grown in the laboratory and in the field

The effect of methyl jasmonate (MJ) spraying on the chemistry of Brassica plants was investigated. Glucosinolates (GLS) in the leaves, stems, and roots of laboratory-grown oilseed rape (Brassica rapa subsp. oleifera cv. Tuli and Valo) 3 and 7 days after MJ treatment were analyzed. Volatile organic compounds (VOCs) from whole oilseed rape plants were collected 3 days after MJ treatment. GLS were also analyzed from field-grown oilseed rape (cv. Valo) treated with MJ. The production of indolyl GLS in laboratory-grown oilseed rape, especially the concentration of 4-hydroxy-3-indolylmethyl (4-OH-glucobrassicin) in leaves, stems, and roots, 3-indolylmethyl (glucobrassicin) in stems, and 4-methoxy-3-indolylmethyl (4-methoxyglucobrassicin) in roots, was induced after MJ treatment. The VOC emission profile changed after MJ treatment, and homoterpene (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) was detected only in MJ-treated plants. The GLS concentration in the field-grown plants was significantly higher in MJ-treated plants than in control plants. These results suggest that spraying with MJ induces the production of secondary compounds, that is, GLS and VOCs, in Brassica plants. The induction of VOC emissions in oilseed rape is comparable to that caused by insect feeding damage. Thus, MJ-treated crop plants may become less palatable to insect herbivores and more attractive to natural enemies of herbivores.     

Profitability, Liquidity and Solvency of Wood Harvesting Contractors in Finland

In order to respond to global competition challenges, the wood-processing industry in Finland and elsewhere is outsourcing roundwood harvesting to harvesting contractors. The industry also seeks to negotiate with fewer, larger and more diverse contractor enterprises. The weak profitability, liquidity and solvency of harvesting contractors and the consequent difficulty in hiring qualified machine operators make networking and enterprise growth a complicated process. Financial data of 1,060 Finnish wood harvesting contractors from the period 2001 to 2007 were studied using the ‘closing of the accounts’ data. The material represents most of the full-time contractors. For 2007 net profit was about 6%, credit share of turnover over 50% and median financial reserve €18,000. High machine depreciation and interest expenses together with low solidity make it difficult for small enterprises to absorb seasonal variations and to cope with recessions. Profitability varies considerably amongst smallest enterprises, which most often are sole-operator enterprises. Moreover, even the median profit of the smallest enterprises tends to be negative, which means that enterprise capital will be consumed and many enterprises are at risk of failure. Larger enterprises are more likely to be limited liability companies. Their median profit is clearly positive and the profit varies relative little between enterprises.     

Influence of Protein Level and Supplementary L-Methionine and Lysine on Growth Performance and Fur Quality of Blue Fox ( Alopex lagopus )

The influence of dietary protein content and composition on growing-furring blue fox ( Alopex lagopus ) was studied with three protein levels [15%, 22.5% and 30% of metabolizable energy (ME) from protein]. The two lowest diets were fed as such, or as supplemented with L-methionine or lysine. Growth, from the start of the experiment in July to mid-September, improved with increasing protein level ( P < 0.01). Lysine supplementation, unlike methionine, decreased early growth ( P <0.05). During the last months of the experimental period, differences in weight gain between the groups evened out. Skin length and quality declined with decreasing protein level ( P <0.05). Methionine and lysine had opposite effects on skin length ( P <0.10). For normal body growth and skin length, a level of 0.40 g of digestible L-methionine MJ -1 ME, and 25-32% protein in feed dry matter, was required. When feed ingredients are deficient in methionine, a supplementation is recommended. Methionine is the first limiting amino acid of the two amino acids studied here.     

Combined effects of dietary malic acid and Bacillus subtilis on growth,gut microbiota and blood parameters of Nile tilapia (Oreochromis niloticus)

The study investigated effect of dietary supplementation with malic acid, Bacillus subtilis and a mixture of the two (3 × 2 factorial trial) on Nile tilapia (Oreochromis niloticus) health. Treatment groups (T1–T6) were fed diets containing three levels of malic acid (0.0, 5.0 and 10.0 g/kg), each of which was supplemented with 0 and 1.1 × 10⁵ cfu/g B. subtilis, respectively. Each treatment group was assigned randomly to triplicate groups of 35 fish (5.26 ± 0.06 g) in 18 tanks for 84 days. The results indicated that survival was higher in all dietary treatments as compared to the control fed fish. The highest values of FBW, WG and SGR (%), PER, PPV and ER were recorded in groups T4 and T6, which were fed diets supplemented with 5 g malic acid/kg and 1.1 × 10⁵ cfu/g B. subtilis and 10 g malic acid/kg and 1.1 × 10⁵ cfu/g B. subtilis, respectively. The best value of FCR was obtained in groups T4 and T6. The lowest total bacterial count in the gut and faeces was detected in fish from group T6. The values of haematocrit, haemoglobin, red blood cells, white blood cells, total protein, albumin and globulin were significantly higher (p < .05) in fish from groups T4 and T6 (diets supplemented with malic acid and B. subtilis). As compared to the control fed fish, te mixture of these substances are promising as immune enhancher in aquacultured fish.