polymethylmethcrylate reactors with a volume of approximately 50 ml (diameter and hight of vessels were ~3.75 cm and 4 cm respectively). Exact volumes for each reactor were determined gravimetrically. One gram of soil within each reactor was kept suspended by a magnetic stir plate and a teflon coated stirbar (SpinRing®) stirring at a rate greater than 100 revolutions/min elevated on four Teflon legs to minimize contact with the surface of the reactor. The effluent passed through a 0.025 µ m mixed cellulose acetate and nitrate membrane Millipore filter mounted on a 47 mm polypropylene filter holder, which capped the reactors. A peristaltic pump was used to adjust the flow rate, which varied from 0.02 – 0.4 ml/min. The pumps were set at the relatively fast rate of 0.4 ml/min at the beginning of each experiment to minimize the length of time of the rapid initial dissolution stage; as the release of Al and Si stabilized the flow rate was reduced to 0.02 ml/min, where it was held constant during the later part of the experiment when steady-state dissolution rates were measured. To retard microbial growth, 1
Starch concentration in Ginkgo leaves reached 60% of the leaf on a dry weight basis in response to elevatedcarbondioxide (Chapter 3, Table 1), a value considerably higher than the 14% found in Control leaves. The Control treatment value is comparable with starch values measured on broadleaved trees (e.g. Rey and Jarvis 1998) and the deciduous conifers Metasequoia (Dawn Redwood), and Taxodium (Cypress) (Osborne and Beerling 2003). Other studies have found similarly large starch concentration enrichments in response to lower levels of carbondioxide than used in this study. For example, Sholtis et al. (2004) found starch levels were 27% higher in plants grown at ~650 ppm that in control plants. With continued carbondioxide exposure, the amount of starch enrichment varies seasonally, but stays enriched from year to year (Osborne and Beerling 2003, Rey and Jarvis 1998, Schapendonk et al. 2000). While previous research has not documented direct involvement of starch in feedback inhibition, it seems
activity have been reported in previous studies in which food was withheld during behavioral observations (e.g., Munday et al. 2013, 2014; Pimentel et al. 2014; Rossi et al. 2015). We also used a relatively small behavioral arena in relation to fish size compared with some previous studies (e.g., Ferrari et al. 2011a, b), which may have restricted the magnitude of the change in activity of the fish in response to the predator cue. Whether a larger arena would have allowed for a greater reduction in movement following cue injection is unclear. Nevertheless, despite the smaller arenas, the reaction by the fish in our experiment was the same regardless of CO 2 accli-
(7.5 mm) and high (10 mm) were imposed. Soybean genotypes namely S21-N6 was planted in each soil mois- ture level (soil monolith) at 60 cm between two rows by opening small furrow of 5 cm depth and placing soy- bean seeds at 10 cm apart on 25 October 2011. After sowing, each soil monolith was irrigated to 80% field wa- ter capacity (FWC) and uniform soil moisture was maintained in the entire soil profile by daily watering for ini- tial 15 days after planting (DAP) since these rhizotron monoliths were dry before. Two rhizotron chambers were maintained at maximum temperature of 25˚C and minimum of 15˚C, and at 380 µmol mol −1 [CO
Similar to stomatal density-related traits, stomatal size (S), as measured by GCL in the present work, also showed wide variation among different ecotypes in its response to CE (Fig. 4 and Table S2). Our results are only in limited agreement with the observed increases of GCL with CE on both geologic (Franks and Beerling 2009) and short experimental (Lomax et al. 2009) time scales as only two (Col-0 and Ba-1) and three (Lc-0, Ll-0 and Edi-0) ecotypes respectively showed increased abaxial and adaxial GCL in response to CE. However, Franks and Beerling (2009) noted that magnitude of change in S in short-term ECO 2
Some experiments growing soybeans at different carbondioxide concentrations have indicated that carbon dio- xide concentration may affect the time of initial flowering (reviewed in Ellis et al. 1995). In some cases first flowering was earlier at elevated than at lower carbondioxide, while the opposite response occurred in some other cases  . No change has also been found in other cultivars. Comparisons of soybean cultivars at am- bient and elevatedcarbondioxide both in indoor controlled environment chambers and in the field indicated that the duration of vegetative growth, as affected by flowering phenology, was a significant source of variation in the stimulation of yield by elevatedcarbondioxide . Thus adaptation of soybeans to rising atmospheric car- bon dioxide may benefit from a better understanding of carbondioxide effects on flowering.
same direction as adaxial SD. Conversely, in several ecotypes abaxial and adaxial SI showed significant responses to CE despite their respective SDs not showing significant CE responses. This was observed in Lc-0 and Ll-0 with respect to abaxial SI and SD and in Bla-1, Su-0, Ts-1 and Edi-0 with respect to adaxial SI and SD. In Lc-0, Ll-0 and Su-0, the respective ED also did not show a significant CE response. In contrast, in Bla-1, Ts-1 and Edi-0, the respective ED increased significantly while the SI decreased significantly. It was only rarely that the respective SD and SI showed opposite responses to CE. This was observed in Lan-0 and Wil-2 with respect to abaxial SD and SI, where SD increased while SI decreased. In both these ecotypes, the above changes in abaxial SD and SI were accompanied by significant increases in abaxial ED. In contrast, none of the ecotypes showed opposite responses to CE in their adaxial SD and SI.
In addition to hexokinase, SnRK1 has been indicated as another sugar sensor which is involved in a sucrose/T6P signaling network and operates as a starvation response (Baena-Gonzalez et al., 2007). It has been observed that SnRK1 may be inhibited by the presence of sucrose. KIN10, a part of the SnRK1 complex, is activated under sugar starvation, leading to up-regulation and down-regulation of various genes (Baena-Gonzalez et al., 2007). SnRK1 also contributes to increasing sugar content in plants by phosphorylating both sucrose phosphate synthase (SPS) and trehalose-phosphate synthase (TPS; Nukarinen et al., 2016), of which the resulting sugars, sucrose and T6P, may lead to inactivation of SnRK1 (Baena-Gonzalez et al., 2007; Zhang et al., 2009). Sucrose concentrations are linked with T6P levels, as increased sucrose leads to stimulation of TPS which in turn increases T6P concentrations (Yadav et al., 2014). High T6P then causes a decline in sucrose content which prevents further increases in T6P (Yadav et al., 2014). The regulation of T6P content is primarily linked with sucrose content, as studies have shown that only sucrose and hexoses able to be converted to sucrose have a significant effect on T6P levels (Lunn et al., 2006; Yadav et al., 2014). Sucrose and T6P may also be involved together with nitrogen assimilation, where increases in T6P signal the plant to synthesize organic and amino acids rather than sucrose (Figueroa et al., 2016). In conjunction with T6P other similar sugar phosphates, glucose 1-phosphate (G1P) and glucose 6-phosphate, are able to inhibit SnRK1, with G1P working together with T6P to significantly increase this inhibition (Nunes et al., 2013). Altogether SnRK1 appears to be involved in the plant’s starvation response, inactivating during times of sufficient sucrose/T6P and activating when these signals are low.
C 3 , C 4 and CAM plants differentially (Poorter 1993). CO 2 t enhances the growth rate of almost all plants (Kimball 1983) but the enhancement was very significant in C 3 species. C 3 plants (rice, wheat, oil seeds, pulses etc.) respond to elevated CO 2 by reducing the oxygenase activity of RuBP carboxylase/oxygenase, enzyme resulting in the suppression of photorespiration (Long and Drake 1992). C 4 plants (maize, sorghum, sugarcane etc.) show little or no photosynthetic response to el- evated CO 2 , because they are CO 2 saturated and not competitively inhibited by O 2 . The increase in CO 2 is expected to cause global warming by absorbing the long wave heat radiation from the earth surface and altering the precipitation (Moya et al. 1998) – i.e. climatic effect. According to global circula- tion models (GCMs), the temperature changes may not be uniform. At polar regions it may increase by 4–5°C and at equator by less than 1°C. From 1860 to 2000, the global average surface temperature increased by 0.6°C ± 0.2°C. The Third Assessment Report (TAR) of IPCC projects a global average warming of 1.4 to 5.8°C by the year 2100.
Dissolved oxygen concentration in the inner, focal chamber was measured every 2 s and logged using a Fire-Sting ﬁ bre- optic oxygen meter (Pyroscience, Germany), connected to a computer. The oxygen-sensing optode was mounted in the recirculation loop in a ﬂ ow-through cell, to ensure that ﬂ ow was suf ﬁ cient for a fast response time of the sensor (Svendsen et al. , 2016). Focal ﬁ sh were fasted for 24 – 26 h before experi- mentation to ensure that they were in a post-absorptive state and were left undisturbed in the respirometers for 17 – 19 h overnight, as C. viridis is quiescent at night. A dim light remained on through the night in the laboratory to simulate moonlight, allowing the focal ﬁ sh to see their shoal-mates in group testing trials. Activity was recorded during daylight hours using a webcam (H264 Webcam software) and was measured by counting the number of 180 ° turns for 10 min/h of testing (from which turns/min was calculated). Activity was recorded to ensure that any measured effects of CO 2 on oxy-
of the crop to determine its growth and yield response. The plants exposed to elevated CO 2 showed increase in growth characteristics, viz. shoot length, total number of branches and leaf area per plant. Significant increase in leaf and shoot dry weight was recorded in elevated CO 2 grown plants. The concentration of non structural carbohydrates such as sugars and starch in leaves was higher under elevated CO 2 grown plants, which indicated higher photosynthetic activity. Total carbon concentration increased but the nitrogen concentration decreased in the leaves and resulted in higher C/N ratio. The seed yield of elevated CO 2 grown plants was higher due to significant increase in number of seeds per plant. This study suggests that rising atmospheric CO 2 in future may increase dry matter production and yield in chickpea but reduction in nitrogen concentration may alter their protein levels.
Jack pine (Pinus banksiana Lamb.) is a major tree species in the boreal forests of Canada holding great eco- logical and commercial values and thus deserves special attention in the context of climate change. Jack pine is the second most planted tree species in Canada after black spruce  . In Ontario jack pine comprises ap- proximately 37% of the total annual softwood harvest . Atmosphere Ocean General Circulation Models pre- dict a 10 degree (approximately 1000 kilometers) northward shifts in the climate envelopes of 130 North Amer- ican tree species between 2071 and 2100  . Following the predicted shift in climate envelopes jack pine might need to migrate 10 ˚ northward between 2071 and 2100 . In that case, the species will be exposed to a different photoperiod regime, e.g. the photoperiods will be longer in the summer and shorter in the winter with faster transition between seasons than the regimes that it has adapted to, which might affect the phenological events of the species. But, the impacts of changes in photoperiod regimes associated with migration or seed transfer of jack pine are not yet well documented. Since the impacts of elevated atmospheric [CO 2 ] and warmer
ering rates (Neaman et al., 2006; Drever and Stillings, 1997). In soil systems LMWOA concentrations are a result of pro- duction, microbial uptake rates, and adsorption (van Hees et al., 2005). LMWOA concentrations may have been consid- erably higher near mineral surfaces and under biofilms than those we measured; however the rhizosphere samplers were placed in the zone of highest root activity. LMWOAs repre- sent one of a few possible weathering-promoting ligands of biotic origin and commonly comprise less than 10 % of dis- solved organic carbon (Strobel, 2001). Organic compounds that are generally found in much lower concentrations than LMWOAs may be key ligand-promoted weathering agents in soil, such as siderophores (Lierman et al., 2000; Reichard et al., 2007; Watteau and Berthelin, 1994), which are exuded by EMF (van Hees et al., 2006) and bacteria (Liermann et al., 2000). We did not find detectable levels of iron or aluminum in column leachate (< 0.1 µM of Al and Fe vs. > 50 µM of Si, data not shown), and thus siderophores were not likely a sig- nificant contributor to biotic weathering enhancement in our system.
Density fractionation of soil samples was performed at the time of microcosm construction and at the end of the 230-d incubation, following a procedure adapted from Sollins et al. (1984) and Tu et al. (2006). Soil samples (10 g) were placed in 50 ml polycarbonate centrifuge tubes and filled with 45 ml of 1.6 g ml -1 KI solution. The tubes were shaken by hand and left at room temperature for 2 h. The supernatant containing organic matter (OM) with density lower than 1.6 g ml -1 , regarded as the first fraction, was gently removed from tubes by pipetting. The residual > 1.6 g ml -1 -dense fraction, regarded as the second fraction, was then washed with 10 ml of DI water by centrifugation (3x), oven dried at 60 °C and ground to fine powder for future isotope analysis. Here, the first fraction (d < 1.6 g ml -1 ), is considered mineral-free particulate organic matter (POM), and the second fraction (d > 1.6 g ml -1 ) is the mineralsoil fraction, containing completely humified fine POM, relatively OM-free sand and OM-rich clays ( Baisden and Amundson 2002).
duction. Increased investment in flowers may have implications for pollination in entomophilous plants. Floral nectar standing crop, flower production and longevity were examined in Vicia faba, field bean, at ambient and elevated CO 2 . Nectar standing crop did not differ significantly between treat- ments but plants grown at elevated CO 2 produced approximately 25% more flowers per plant and these lived 17% longer than those grown at ambient CO 2 . A plant grown at elevated CO 2 may thus pro- duce more nectar in total and, together with its increased floral display, may be more attractive to pol-
Batch experiments provide measurements of dissolution rates in fluid-dominated settings in which the reaction affinity changes as equilibrium is approached. Progressive sampling of solution in the course of the experiment changes the proportion of mineral to fluid so that the amount of mineral dissolution needed to produce a given change in fluid composition gradually decreases as the experiment proceeds. An alternative approach is to carry out experiments in which fluid flows at a steady rate through the experimental vessel and is sampled at the exit point (Fig. 3d). The composition of the exit fluid is considered representative of that inside the vessel. Mixing ensures fluid homogeneity and stirring rate is fixed in order to avoid mass transport limitations on the reaction rate. In flow-through reactors, the composition of the introduced fluid remains constant, so that the reaction affinity reaches a steady state. As a result, conditions are likely to be further from equilibrium than is the case for batch experiments, but affinity remains constant. Dove and Crerar (1990) developed a hydrothermal mixed flow-through reactor capable of working over the range of pressure-temperature conditions appropriate to GCS. This approach was further developed by Carroll and Knauss (2005) for experiments with CO 2 -bearing fluids.
Such satisfactory result might be due to the prevailing bio-fertilizer supplemented organic fertilizer improved soil properties, especially organic matter and N content. The application of bio-fertilizer in combination with organic or mineral fertilizers increased the efficiency of both organic and mineral N fertilizer, but apply the bio-fertilizer alone was ineffective in increasing yield. Thus, bio-fertilizers could be used as value-added soil amendments by supplementing organic and low chemical fertilizer rates for improving soil fertility and sustaining crop productivity (Abbasia and Yousra, 2012). Also, other authors mentioned the same results bio-fertilizer is enhancing soil biological activity, which improved nutrient mobilization from organic and chemical sources. Also, the bio-fertilizer plays a significant role in regulating the dynamics of organic matter decomposition and the availability of plant nutrients and increasing nitrogen fixer. In this case, Elsayed et al., 2005; El-Garhi et al., 2007; Badr et al., 2009; Bahrani et al., 2010; Abd El-Lattief, 2012 found positive effect on yield and yield attributes of wheat when inoculated with bio-fertilizer. Controlled field trials in Iran, Khavazi et al., 2005, found that yield improvements of more than 20% have been observed for wheat as a result of application of bio-fertilizer inoculums.
results.obtained, with those reported by Pool;(1952,1953),/ ; ; \ : X for tap water compared with Hoagland solution pretreatment® ; ; : ÿV :î; Beoondly, to study the of foot of the oarbohydrate status .on - : ■ ' X.:’ carbondioxide fixation, .'and, to determine if this is a :, . a/ ;X. / .X limiting factor.to carbondioxide assimilatlbn In foots ■ X : which have been, pretreated in a minefal salt éolùtion® . ' ‘ " '^;X ■ ‘ Thirdly, to Undertake a series of experiments . to study . -V . v;^ : oafbon dioxide fixation .In relation to the relative anionscation status of the'roots,; using solutions of single salts,from ; : ; which diffèrent relative amounts of anions and cations are ..