Effects of increased autumn temperatures and sub-acute levels of ammonia on post-winter development of four cultivars of winter oilseed rape (Brassica napus L.)

Early planting dates, warm autumns and increased N mineralisation  rates may advance the growth of winter crops and also a high supply of nitrogen poses risks of excess biomass accumulation before the winter leading to reduced frost hardiness and excessive leaf loss. Although the number of frost days is currently declining in temperate Europe, events of frost may still create damage in the future in winter crops that have accumulated too much biomass in the preceding autumn.Here we report on a study in which the responses of four cultivars of winter oilseed rape (OSR) to elevated autumn temperatures and subacute levels of ammonia (NH3) were compared. It has been suggested that high concentrations of the gas, e.g. in livestock intensive regions may both act as an airborne fertiliser and reduce the frost hardiness of plants. Advancing treatments were imposed for 88 days in the autumn and consisted of pot grown plants kept in greenhouses without (ELVT) and with elevated concentrations of ammonia (ELVT+A; 195 μg m-3 NH3). Reference plants (AMB) were raised outdoors, where temperatures were 1.4°C lower than in the greenhouses.After the treatments plants were all overwintered outside to study whether the pre-winter growth advancement was still discernible in the following spring. Shed leaves were collected weekly to follow how much shoot biomass was lost during and after the winter. Cultivars responded differently to warming and exposure to ammonia. Up to the winter shoot biomass was strongly increased by the advancing treatments. However, fi nal shoot mass in the following summer did not differ between cultivars and was unaffected by the higher temperatures in the preceding autumn. Nevertheless, significantly more biomass was observed in ammonia fumigated plants. Higher autumn temperatures increased leaf shedding and advanced fl owering and senescence in the next spring so that plants showed a signifi cantly reduced seed mass, harvest index and oil yield at the fi nal harvest. Obviously, the growth advancement in the preceding autumn by elevated temperatures negatively affected the availability of resources in the following spring. In contrast, plants that were grown at both elevated ammonia and temperature in the autumn showed a delayed fl owering, higher shoot and seed mass, increased harvest index and oil yield. We conclude that growth advancement by elevated autumn temperatures without the re-supply of nutrients increases leaf shedding during winter. Nevertheless, the loss of resources in winter for re-growth in spring will certainly be of minor importance for yield formation as compared to the frost damage resulting from late spring frosts

On the consistencies between CSR plant strategies and Ellenberg ecological indicator values

One strand of British comparative plant ecology has used experimental measurements of innate traits under standardized conditions to confirm plant ‘strategies’ or ‘functional types’. The Sheffield (Grime) school has now established CSR-signatures for 1010 species. In contrast, a Central-European approach (Göttingen or Ellenberg school) has emphasized the unity of plants with their natural habitats by allocating ‘ecological indicator values’ (EIV´s; German: Zeigerwerte) for over 2700 species, which describe the ecological behavior of each species in their plant associations. In this paper we assess the levels of compatibility and congruence between these two approaches using large datasets that include some previously unexamined traits. Despite there being a wide gap between these plant- and environment-based starting points, we discover that both approaches lead to similar conclusions regarding patterns of evolutionary tradeoffs and ecological processes. In particular, the comparisons support the major evolutionary generalization that plant life has, in effect, aligned itself along a continuum between one trait-group that confers rapid acquisition of resources and another that confers long-term resource conservation

Effects of elevated CO2 concentrations and fly ash amended soils on trace element accumulation and translocation among roots, stems and seeds of Glycine max (L.) Merr.

The carbon dioxide (CO2) levels of the global atmosphere and the emissions of heavy metals have risen in recent decades, and these increases are expected to produce an impact on crops and thereby affect yield and food safety. In this study, the effects of elevated CO2 and fly ash amended soils on trace element accumulation and translocation in the root, stem and seed compartments in soybean [Glycine max (L.) Merr.] were evaluated. Soybean plants grown in fly ash (FA) amended soil (0, 1, 10, 15, and 25% FA) at two CO2 regimes (400 and 600 ppm) in controlled environmental chambers were analyzed at the maturity stage for their trace element contents. The concentrations of Br, Co, Cu, Fe, Mn, Ni, Pb and Zn in roots, stems and seeds in soybeans were investigated and their potential risk to the health of consumers was estimated. The results showed that high levels of CO2 and lower concentrations of FA in soils were associated with an increase in biomass. For all the elements analyzed except Pb, their accumulation in soybean plants was higher at elevated CO2 than at ambient concentrations. In most treatments, the highest concentrations of Br, Co, Cu, Fe, Mn, and Pb were found in the roots, with a strong combined effect of elevated CO2 and 1% of FA amended soils on Pb accumulation (above maximum permitted levels) and translocation to seeds being observed. In relation to non-carcinogenic risks, target hazard quotients (TQHs) were significant in a Chinese individual for Mn, Fe and Pb. Also, the increased health risk due to the added effects of the trace elements studied was significant for Chinese consumers. According to these results, soybean plants grown for human consumption under future conditions of elevated CO2 and FA amended soils may represent a toxicological hazard. Therefore, more research should be carried out with respect to food consumption (plants and animals) under these conditions and their consequences for human health.Fil: Rodriguez, Judith Hebelen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Klumpp, A.. Universität Hohenheim. Institute of Landscape and Plant Ecology; AlemaniaFil: Fangmeier, A. Universität Hohenheim. Institute of Landscape and Plant Ecology; AlemaniaFil: Pignata, Maria Luisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentin

Foraging enrichment alleviates oral repetitive behaviors in captive red-tailed black cockatoos (Calyptorhynchus banksii)

The relationship between inadequate foraging opportunities and the expression of oral repetitive behaviors has been well documented in many production animal species. However, this relationship has been less‐well examined in zoo‐housed animals, particularly avian species. The expression of oral repetitive behavior may embody a frustrated foraging response, and may therefore be alleviated with the provision of foraging enrichment. In this study, we examined the effect of different foraging‐based enrichment items on a group of captive red‐tailed black cockatoos who were previously observed performing oral repetitive behavior. A group of six cockatoos were presented with five foraging enrichment conditions (no enrichment (control), sliced cucumber, fresh grass, baffle cages, and millet discs). Baseline activity budgets were established over a 10‐day preintervention period and interventions were then presented systematically over a 25‐day experimental period. This study demonstrated that the provision of foraging interventions effectively increased the median percentage of time spent foraging compared to control conditions (range, 5.0–31.7% across interventions vs. 5.0% for control), with two of the interventions; grass and millet discs, significantly decreasing the expression of oral repetitive behaviors (control = 16.6 vs. 8.3% for both grass and millet discs). Finally, a rapid‐scoring method utilized by zookeepers during the study proved to be a useful proxy for the amount of time the cockatoos spent interacting with the foraging interventions and overall time spent foraging

Accumulation of Aluminium and Physiological Status of Tree Foliage in the Vicinity of a Large Aluminium Smelter

A pollution gradient was observed in tree foliage sampled in the vicinity of a large aluminium production facility in Patagonia (Argentina). Leaves of Eucalyptus rostrata, and Populus hybridus and different needle ages of Pinus spec. were collected and concentrations of aluminium (Al) and sulphur (S) as well as physiological parameters (chlorophyll and lipid oxidation products) were analyzed. Al and S concentrations indicate a steep pollution gradient in the study showing a relationship with the physiological parameters in particular membrane lipid oxidation products. The present study confirms that aluminium smelting results in high Al and sulphur deposition in the study area, and therefore further studies should be carried out taking into account potentially adverse effects of these compounds on human and ecosystem health

Does elevated atmospheric CO2 allow for sufficient wheat grain quality in the future?

To identify future impacts on biomass production and yield quality of important C3 crops, spring wheat was grown in association with 13 weed species in a Mini-FACE (free-air carbon dioxide (CO2) enrichment) system under ambient (375 μl l-1) and elevated (526 μl l-1) CO2 concentrations. Wheat productivity was assessed at maturity and grain yield was subjected to various chemical analyses and baking quality tests.CO2 enrichment acted as carbon ‘fertiliser’ and increased the aboveground biomass production of wheat by 18.8% as there was a trend towards higher stem biomass. Although not statistically significant, wheat grain yield was increased by 13.4% due to a significant establishment of more grains per unit ground area. At the same time, thousand grain weight was non-significantly shifted towards smaller grain size classes, which may result in negative consequences for the crop market value. As a result of the CO2- induced physiological and biochemical modifications, concentration of total grain protein was significantly decreased by 3.5%, reducing the wheat grain quality with potentially far-reaching impacts on the nutritional value and use for processing industry. Although often not significant, the concentrations of amino acids per unit of flour were decreased by 0.2 to 8.3% due to elevated CO2 thereby affecting the composition of proteinogenic amino acids.Furthermore, gluten proteins tended to decline. Within the significant decreased gliadins, α- and ω5-gliadins were significantly reduced under CO2 enrichment; there was also a negative trend for ω1,2- and γ-gliadins. Changes in certain essential minerals were found as well, although not statistically significant. Concentrations of sodium, calcium, phosphorus and sulphur were slightly lowered and those of potassium and magnesium were slightly increased due to CO2 enrichment. The micro-element molybdenum was increased, while concentrations of iron, zinc, copper, manganese and aluminium were decreased. With regard to rheological and baking parameters defining the cereal quality for industrial processing, the resistance of the dough was significantly reduced by about 30%, while the extensibility was non-significantly increased by 17.1% under CO2 enrichment. Moreover, the bread volume was decreased non-significantly by about 9%. Elevated CO2 is obviously affecting grain characteristics important for consumer nutrition and health, industrial processing and marketing. Experimental evidence for these changes is still poor but deserves further attention

Nitrogen enrichment enhances the dominance of grasses over forbs in a temperate steppe ecosystem

Chinese grasslands are extensive natural ecosystems that comprise 40 % of the total land area of the country and are sensitive to N deposition. A field experiment with six N rates (0, 30, 60, 120, 240, and 480 kg N ha<sup>−1</sup> yr<sup>−1</sup>) was conducted at Duolun, Inner Mongolia, during 2005 and 2010 to identify some effects of N addition on a temperate steppe ecosystem. The dominant plant species in the plots were divided into two categories, grasses and forbs, on the basis of species life forms. Enhanced N deposition, even as little as 30 kg N ha<sup>−1</sup> yr<sup>−1</sup> above ambient N deposition (16 kg N ha<sup>−1</sup> yr<sup>−1</sup>), led to a decline in species richness. The cover of grasses increased with N addition rate but their species richness showed a weak change across N treatments. Both species richness and cover of forbs declined strongly with increasing N deposition as shown by linear regression analysis (<i>p</i> < 0.05). Increasing N deposition elevated aboveground production of grasses but lowered aboveground biomass of forbs. Plant N concentration, plant δ<sup>15</sup>N and soil mineral N increased with N addition, showing positive relationships between plant δ<sup>15</sup>N and N concentration, soil mineral N and/or applied N rate. The cessation of N application in the 480 kg N ha<sup>−1</sup> yr<sup>−1</sup> treatment in 2009 and 2010 led to a slight recovery of the forb species richness relative to total cover and aboveground biomass, coinciding with reduced plant N concentration and soil mineral N. The results show N deposition-induced changes in soil N transformations and plant N assimilation that are closely related to changes in species composition and biomass accumulation in this temperate steppe ecosystem