Seed growth rate and carbohydrate pool sizes of the soybean fruit

The relationships between various carbohydrate pools of the soybean (Glycine max [L.] Merrill) fruit and growth rate of seeds were evaluated. Plants during midpod-fill were subjected to various CO₂ concentrations or light intensities for 7 days to generate different rates of seed growth. Dry matter accumulation rates of seeds and pod wall, along with glucose, sucrose, and starch concentrations in the pod wall, seed coat, and embryo were measured in three-seeded fruits located from nodes six through ten. Seed growth rates ranged from 4 to 37 milligrams·day⁻¹·fruit⁻¹. When seed growth rates were greater than 12 milligrams·day⁻¹·fruit⁻¹, sucrose concentration remained relatively constant in the pod wall (1.5 milligrams·100 milligrams dry weight⁻¹), seed coat (8.5 milligrams·100 milligrams dry weight⁻¹), and embryo (5.0 milligrams·100 milligrams dry weight⁻¹). However, sucrose concentrations decreased in all three parts of the fruit as growth rate of the seeds fell below 12 milligrams·day⁻¹·fruit⁻¹. This relationship suggests that at high seed growth rates, flux of sucrose through the sucrose pools of the fruit was more important than pool size for growth. Starch concentration in the pod wall remained relatively constant (2 milligrams·100 milligrams dry weight⁻¹) at higher rates of seed growth but decreased as seed growth rates fell below 12 milligrams·day⁻¹·fruit⁻¹. This suggests that pod wall starch may buffer seed growth under conditions of limiting assimilate availability. There was no indication that carbohydrate pools of the fruit were a limitation to transport or growth processes of the soybean fruit.     

The impact of effluents of Pitkäranta pulp mill on the water quality of Lake Ladoga: a model study

The aim of this study is to show the effects of the Pitkäranta pulp mill on the water quality of Northern Ladoga by using water quality models. The effluent loading of the pulp mill with its full production capacity is as follows: Water flow 85 000 m³ d^–1 BOD₅ 2.4 t d^–1 Suspended solids 4.1 t d^–1 tot-N 330 kg d^–1 tot-P 68 kg d^–1 COD(Cr) 14.4 t d^–1 Org. C 6 t d^–1 Lignosulphonates 9.4 t d^–1 Loadings of lignosulphonates and organic C are estimations. Lignosulphonate concentrations of 10.5 mg 1^–1 have been reported in the region of Pitkäranta. The study area of northern Ladoga near the pulp mill was divided into three zones (I, II and III). The mean depth of each of them is considered as 10 m, their respective areas 5, 10 and 50 km², and volumes 50, 100 and 500 million m³. The estimated discharges of the zones are 10, 20 and 50 m³ s^–1, respectively. With the aid of simple water quality models the effects of the pulp mill effluents on the concentrations of oxygen, total phosphorus, lignin, COD(Mn) and Secchi disk depths in each of the zones were estimated. Estimations were made during full production capacity and half production capacity of the pulp mill. The modelling results were compared with the preliminary water analysis results of the Finnish-Russian joint research expedition into Lake Ladoga in August 1993. The results show that near the pulp mill (zone I) phosphorus concentrations are high even with half production capacity. Also lignin and COD(Mn) contents have increased, and oxygen concentrations are low both in the summer and during wintertime. Farther away in the open water (zone III) the pollution effects are low. Eutrophication, indicated by high total phosphorus concentrations, is the main effect of the pulp mill effluents.     

Ex situ bioremediation of pyrene contaminated soil in bio-slurry phase reactor operated in periodic discontinuous batch mode: Influence of bioaugmentation

Ex situ treatment of simulated pyrene-contaminated soil was studied in bio-slurry phase reactors operated in periodic discontinuous batch mode under anoxic–aerobic–anoxic–anoxic microenvironment. Experiments were performed in six different bio-slurry phase reactors (retention time of 120 h; soil loading rate of 20 kg soil/m³-day; operating temperature at 28±2 °C) by varying substrate concentration (substrate loading rate (SLR), 0.12, 0.24 and 0.36 g pyrene/kg soil-day) and bioaugmentation application (domestic sewage inoculum; CFU—2×10⁶). The performance of slurry phase reactors was found to be dependent on the applied SLR and application of bioaugmentation (domestic sewage as augmented inoculum). Control reactor (killed control) showed only 6% of pyrene degradation while the non-augmented reactor showed an efficiency of 34% (substrate degradation rate (SDR)—0.0165 g pyrene/kg soil-day). In the case of augmented reactors, the system operated with low SLR showed a pyrene degradation efficiency of almost 90% (SDR—0.04 g pyrene/kg soil-day) and the reactor with high SLR showed 50% (SDR—0.025 g pyrene/kg soil-day) of pyrene degradation indicating the dependence of performance on the substrate concentration. Colony forming units (CFUs) variation was in good agreement with the performance of the reactors with respect to pyrene degradation. On the whole, pyrene degradation rate was greater in the augmented reactors compared to non-augmented reactors.     

Winemaking of musts at high osmotic strength by thermotolerant yeasts

Fermentation performance of 15 thermotolerant Saccharomyces cerevisiae in three musts from dried grapes at 25, 30, and 40° brix was studied. When the osmotic strength was increased, the volatile acidity and the SO₂ production in the wines also increased: in the must with 40° brix, yeasts produce from 1.63 to 3.65 g acetic acid l^–1 and from 40 to 73.6 mg SO₂ l^–1 due to osmotic stress. From 9.75 to 13.40 ethanol v/v production is observed in must at 30°brix, whereas at 40°brix there is a clear detrimental effect.     

Quantitative analysis of carbon balance in the reproductive organs and leaves of <Emphasis Type="Italic">Cinnamomum camphora</Emphasis> (L.) Presl

We investigated seasonal changes in dry mass and CO₂ exchange rate in fruit and leaves of the evergreen tree Cinnamomum camphora with the aim of quantitatively determining the translocation balance between the two organs. The fruit dry mass growth peaked in both August and October: the first increase was due to fruit pulp development and the second to seed development. Fruit respiration also increased with the rapid increase in fruit dry mass. Therefore, the carbohydrates required for fruit development showed two peaks during the reproductive period. Fruit photosynthesis was relatively high in early August, when fruit potentially re-fixed 75% of respired CO₂, indicating that fruit photosynthesis contributed 15–35% of the carbon requirement for fruit respiration. Current-year leaves completed their growth in June when fruit growth began. Current-year leaves translocated carbohydrates at a rate of approximately 10–25 mg dry weight (dw) leaf⁻¹ day⁻¹ into other organs throughout the entire fruit growth period. This rate of translocation from current-year leaves was much higher than the amount of carbohydrate required for reproduction (ca. 3 mg dw fruit⁻¹ day⁻¹). Given the carbon balance between fruit and current-year leaves, carbohydrates for reproduction were produced within the current-year fruit-bearing shoots. C. camphora would be adaptive for steadily supplying enough amount of carbohydrate to the fruits, as there was little competition for carbohydrates between the two organs. As assimilates by leaves are used for processes such as reproduction and the formation of new shoots, photosynthesis by reproductive organs is considered to be important to compensate for reproductive cost.     

Ethylene binding changes in apple and morning glory during ripening and senescence

Ethylene binding sites were measured during fruit ripening and morning glory flower senescence. Little change in ethylene binding was noted during these developmental stages, except a slight decline during the later stages of fruit ripening or flower senescence. The concentration of ethylene required to achieve 50% saturation of the binding sites was 0.14 l/liter for both apple pulp and morning glory flowers. Ethylene binding sites were calculated to be 3.2×10^–11 moles/kg and 3.8×10^–9 moles/kg in apple and morning glory, respectively. It does not appear that changes seen in ethylene sensitivity during fruit ripening can be readily ascribed to changes in the number of ethylene binding sites in the tissue.Paper No. 11398 of the Journal Series of the North Carolina Agricultural Research Service, Raleigh, NC 27695-7601, USA.     

Removal of carboxymethyl cellulase activity from the culture filtrate of Termitomyces clypeatus producing xylanase

Termitomyces clypeatus produced 450 IU xylanase ml^–1 in a medium containing starch-free wheat bran powder as the carbon source. Carboxymethyl cellulase (CMCase) activity in the culture filtrate was removed by keeping the filtrate at pH 10 for 60 min followed by a change to pH 6. Treatment of Kraft pulp (bamboo) with the filtrate at pH 7 decreased the kappa number from 10.5 to 5 with release of reducing groups equivalent to 0.15 mg glucose g^–1 pulp.     

Soil N mineralization and nitrification in relation to nitrogen solution chemistry in a small forested watershed

Spatial variations in soil processes regulating mineral N losses to streams were studied in a small watershed near Toronto, Ontario. Annual net N mineralization in the 0–8 cm soil was measured in adjacent upland and riparian forest stands using in situ soil incubations from April 1985 to 1987. Mean annual rates of soil N mineralization and nitrification were higher in a maple soil (93.8 and 87.0 kg.ha^–1) than in a pine soil (23.3 and 8.2 kg.ha^–1 ). Very low mean rates of mineralization (3.3 kg.ha^–1) and nitrification (3.4 kg.ha^–1) were found in a riparian hemlock stand. Average NO₃-N concentrations in soil solutions were 0.3–1.0 mg.L^–1 in the maple stand and >0.06mg.L^–1 in the pine stand. Concentrations of NO₃–N in shallow ground water and stream water were 3–4× greater in a maple subwatershed than in a pine subwatershed. Rapid N uptake by vegetation was an important mechanism reducing solution losses of NO₃–N in the maple stand. Low rates of nitrification were mainly responsible for negligible NO₃–N solution losses in the pine stand.     

Adaptations for avian frugivory: assimilation efficiency and gut transit time of Manacus vitellinus and Pipra mentalis

Summary I examined the digestive physiology of two avian frugivores, the golden-collared manakin, Manacus vitellinus, and the red-capped manakin, Pipra mentalis, to discover how these birds extract energy from fruit. Using 14 species of fruit in the natural diet of manakins, I examined the assimilation of nutrients from fruit pulp, fruit passage rates, seed passage rates, and gut morphology. Fruits in the manakins' diets had high water content (average, 84%) and low nutrient concentrations (3 kJ/g wet pulp; 17 kJ/g dry pulp; 1% nitrogen/g dry pulp). Manacus and Pipra did not differ in the average assimilation of energy in fruit pulp (63%), although it varied from 37 to 84% depending on fruit species. Assimilation of total nonstructural carbohydrates in the fruit pulp was very high (86–98%) in both species. Gut evacuation was rapid; maximum transit time of a labeled fruit was 30 min. Seeds passed through the gut faster (Manacus: 15 min; Pipra: 12 min) than the accompanying fruit epidermis (both spp: 22 min). Manakins regurgitated large seeds (>5 mm diameter) in 7 to 9 min. Rapid gut passage time, high assimilation of nonstructural carbohydrates, and the selective regurgitation and rapid elimination of bulky seeds enable manakins to process a large volume of food per day. By increasing rates of fruit intake and gut passage, manakins can effectively increase total nutrient uptake. These adaptations of manakins are requisite for harvesting sufficient nutrients from fruit, due to its low nutrient density, high water content, and bulky seeds.     

Nitrogen and phosphorus budgets for the sub-tropical Richmond River catchment, Australia

Nitrogen and phosphorus budgets were developed forfour sub-catchments in the Richmond River catchmentfor two study years. The catchment is used for avariety of farming pursuits including dairying, beef,cropping, fruit, nuts, forestry, and sugar cane. Eachsub-catchment varies in hydrology, the proportion ofeach land use, and the population density whichenabled a unique opportunity to study fluxes andstorage associated with a variety of environmentalfactors. Total loadings entering each sub-catchmentvaried from 12 to 57 kg ha^–1yr^–1 fornitrogen and 0.25 to 6.6 kg ha^–1yr^–1 forphosphorus with little inter-annual variation.Averaged across the whole catchment, nitrogen fixation(47%) dominated the inputs; fertiliser (26%) andrainfall (21%) made up the next largest inputs.Fertiliser inputs dominated the phosphorus budget(65.5%); rainfall and manures making up 13% and 12%respectively. Produce dominated the outputs of bothnitrogen and phosphorus from the four sub-catchmentsbeing greater than the riverine export. The deliveryof nitrogen to catchment streams ranged from <1 to24% of the total inputs and the delivery of phosphorus to catchment streams ranged from <1 to 39%. Storage of phosphorus in catchment soils varied between –0.32 and 4.46 kg ha^–1yr^–1. Whendenitrification and volatilisation were estimated using data from other studies, storage of nitrogen ranged from 1 to 24 kg ha^–1yr^–1. Despite theepisodic nature of runoff in the sub-tropical RichmondRiver catchment, the magnitude of nutrient fluxes andstorage appear similar to other catchments of theworld which have mixed land use and relatively lowcatchment nutrient loadings.     

The influence of cyclic glucose feeding on a continuous bakers' yeast culture

Conclusions Except for the pronounced adaptation-hysteresis effect, the pulse experiments exhibited the expected trend: deviation from the steady feed reference curve was greatest at lowest dilution rates. Under conditions of lowest glucose level the effect of pulsing would be expected to cause the largest fluctuations in glucose, causing a certain fraction of the cells to ferment. Generally over the entire dilution rate range the biomass production was decreased and the ethanol was increased by pulsing the feed stream. There is, however, some evidence that pulse feeding can trigger quite unexpected results. Point (6) at D=0.3 h^–1 in Fig. 1 exhibit a biomass productivity which was about 20% greater than the continuous feeding reference value (DX=3.6 kg m^–3 h^–1 as compared with 3.0 kg m^–3 h^–1). Such performance would be of significant commercial value, but the poor reproducibility due to adaptation, as seen here, certainly would preclude its application.The results obtained should also be applicable to fed batch operation at the corresponding glucose level. Further experiments including the variation of the glucose feeding period would be necessary to obtain a conclusive picture. The observed phenomena are likely to occur in other fermentations and could eventually explain some of the problems existing with scale up of fermentation processes.Symbols D dilution rate h^–1 - P product (ethanol) concentration kg m^–3 - Q_O2 specific oxygen uptake rate mol kg^–1 s^–1 - Q_CO2 specific CO₂ production rate mol kg^–1 s^–1 - S substrate (glucose) concentration kg m^–3 - X biomass concentration kg m^–3 - Y_P/S yield of ethanol from glucose kg kg^–1 - Y_X/S yield of biomass from glucose kg kg^–1     

Eichhornia crassipes-based tertiary treatment of Kraft pulp mill effluents in Chilean Central Region

This paper presents experimental results on the implementation of Eichhornia crassipes–based tertiary lagoon to treat effluents generated by a 300 ton d^–1 Kraft pulp mill in Chile. Results show that E. crassipes rapidly adapted to the tertiary lagoon conditions. Active growth was maintained even during a cold winter, protected by the wastewater heat content. A 1000 m² seeding area extended to 2300–6200 m² after a month of growth, with a monthly harvested biomass and nitrogen uptake were 1.1–5.4 ton (dry wt.), and 18–127 kg N, respectively. E. crassipes growth was adequately described by a first order model, with an estimated rate constant ca. 0.03 d^–1 and 0.06 d^–1, for winter and summer seasons, respectively. A management strategy based on such model, to account for seasonal variations in growth rate while keeping a constant nitrogen uptake capacity, is proposed here.     

Exchange of N-gases at the Höglwald Forest – A summary

During 4 years continuous measurements of N-trace gas exchange were carried out at the forest floor-atmosphere interface at the Höglwald Forest that is highly affected by atmospheric N-deposition. The measurements included spruce control, spruce limed and beech sites. Based on these field measurements and on intensive laboratory measurements of N₂-emissions from the soils of the beech and spruce control sites, a total balance of N-gas emissions was calculated. NO₂-deposition was in a range of –1.6 –2.9 kg N ha^–1 yr^–1 and no huge differences between the different sites could be demonstrated. In contrast to NO₂-deposition, NO- and N₂O-emissions showed a huge variability among the different sites. NO emissions were highest at the spruce control site (6.4–9.1 kg N ha^–1 yr^–1), lowest at the beech site (2.3–3.5 kg N ha^–1 yr^–1) and intermediate at the limed spruce site (3.4–5.4 kg N ha^–1 yr^–1). With regard to N₂O-emissions, the following ranking between the sites was found: beech (1.6–6.6 kg N ha^–1 yr^–1) >> spruce limed (0.7–4.0 kg N ha^–1 yr^–1) > spruce control (0.4–3.1 kg N ha^–1 yr^–1). Average N-trace gas emissions (NO, NO₂, N₂O) for the years 1994–1997 were 6.8 kg N ha^–1 yr^–1 at the spruce control site, 3.6 kg N ha^–1 yr^–1 at the limed spruce site and 4.5 kg N ha^–1 yr^–1 at the beech site. Considering N₂-losses, which were significantly higher at the beech (12.4 kg N ha^–1 yr^–1) than at the spruce control site (7.2 kg N ha^–1 yr^–1), the magnitude of total gaseous N losses, i.e. N₂-N + NO-N + NO₂-N + N₂O-N, could be calculated for the first time for a forest ecosystem. Total gaseous N-losses were 14.0 kg N ha^–1 yr^–1 at the spruce control site and 15.5 kg N ha^–1 yr^–1 at the beech site, respectively. In view of the huge interannual variability of N-trace gas fluxes and the pronounced site differences in N-gas emissions it is concluded that more research is needed in order to fully understand patterns of microbial N-cycling and N-gas production/emission in forest ecosystems and mechanisms of reactions of forest ecosystems to the ecological stress factor of atmospheric N-input.     

Sulphate dynamics in a northern wetland catchment during snowmelt

Fluxes and stores of SO ₄ ^2– were measured in a small Canadian Shield basin during the 1989 snowmelt. Sulphate flux from the unsaturated zone (14.1 ± 7.3 kg ha^–1) was four times the amount supplied in meltwater and precipitation (3.5 ± 0.4 kg ha^–1). This reflects flushing of soluble S04- from organic and upper mineral soil horizons during melt, which counteracted potential dilution of groundwater SO ₄ ^2– levels by large water inputs to the basin. 35.6 ± 12.4 kg SO ₄ ^2– entered the saturated zone during melt, supplied equally by leaching from overlying soils and conversion of the capillary fringe to phreatic water due to rising water table levels. Streamflow conveyed 70% of the total SO ₄ ^2–1 export of 10.1 ± 2.3 kg ha^–1, and was largely supplied by groundwater discharge from a wotland in the lower portion of the basin. The remaining 30% of total export was via shallow subsurface flow. Results highlight the importance of unsaturated and saturated zone processes for SO ₄ ^2– dynamics and export during snowmelt.     

A method for collecting soil percolate and soil solution in the field

Summary A soil-water extractor is described which uses an absorbent sponge material for sampling soil percolate and solution. Good agreement existed between soil extracts (1:5 soil:water) and extracts obtained from the extractor sponge after equilibration at low water tensions (pF 0–2.5) in the range, 0–100 g/g soil (0–1400 g/ml solution) for solute anions (Cl^-, NO₂ ^- and NO₃ ^–, R² > 0.98), and for ammonium ions (NH₄ ⁺, R²=0.93).Percolate was recovered in a field soil in volumes sufficient to permit analysis of constituents. Concentrations of solute Cl^- ions in these percolates were similar to those in the added water and in percolate from a zero-tension lysimeter. Poor relationships were obtained in the field between soil solution extracts from the sponge and 1:10 soil water extracts. For the present, the soil extractor may be used for sampling and monitoring movement of percolate and solute fronts, in the wetter range of soil water content.     

Effects of harvesting on nutrient leaching in a Norway spruce (Picea abies Karst.) ecosystem on a Lithic Leptosol in the Northern Limestone Alps

On a heavily karstified site in the Northern Limestone Alps (Austria), nutrient budgets and leaching in Norway spruce stands were investigated along a chronosequence (clearcut, 10-year-old plantation (25% cover of planted and naturally regenerated spruce and larch, 75% weed cover) and mature stand). The soils were Lithic Leptosols on very pure limestone. Nutrient fluxes were studied during three growth periods (4–5 months each). Despite of inorganic nitrogen inputs from precipitation between 5 and 10 kg ha^–1, inorganic nitrogen output with seepage water from the mature stand and the regeneration plot was only 0.5–1.2 kg ha^–1 during these periods. In the first and second growth periods after clearcut, inorganic N fluxes with seepage increased to 20 and 30 kg ha^–1, respectively, declining in the third growth period to 8 kg ha^–1. DON output during the growth period was between 3 and 6 kg ha^–1 in the mature stand and 7 and 11 kg ha^–1 in the clearcut as well as in the regeneration plot. K output rates achieved 30 kg ha^–1 in the first, 20 kg ha^–1 in the second and 9 kg ha^–1 in the third growth period after clear-cutting while output rates during the growth periods were less than 2 kg ha^–1 in the mature stand and in the regeneration plot. K pools in the humus layer were only 150–210 kg ha^–1, total K pools including above and below ground biomass in the mature stand were 360 kg ha^–1. Thus, post-harvest hydrological losses comprise a substantial depletion of K for this specific ecosystem. Since precipitation is high in this area (1400 mm a^–1), forest growth is limited by nutrient rather than by water supply. Needle analyses already indicate a deficient potassium supply. Harvesting and post-harvesting losses of K in combination with elevated nitrogen deposition may have negative influences on the stability of forest stands on the studied sites.     

Residual phosphorus in runoff from successional forest on abandoned agricultural land: 2. Hydrological and soluble reactive P Budgets

Residual P from historical farm practices hasbeen linked to elevated soluble reactivephosphorus (SRP) transport in runoff from afield study site in the Catskills Mountains,New York, U.S.A., with a P source assay indicatingthat successional forest floor biomass was themajor contributor to runoff SRP. In thispaper, we assemble hydrological and SRP budgetsthat indicate net SRP loss of 0.123 kgha^–1 yr^–1 occurs from the site(composed of 0.044 kg ha^–1 yr^–1precipitation input, with 0.143 kg ha^–1yr^–1 and 0.024 kg ha^–1 yr^–1losses in runoff and groundwater,respectively). These findings contrast withconservative P cycling reported for undisturbedforests. Coupled hydrological and SRP data areanalyzed suggesting that catchment ambient andequilibrium SRP concentrations corresponding togroundwater and long-term average runoffconcentrations are in the range capable ofcontributing to eutrophication of receivingwaters. A physically based variable sourcearea hydrological model is tested to simulateSRP export using deterministic concentrations. The three-layer model (surface runoff, shallowlateral flow, and groundwater) is parameterizedusing spatially distributed data fromadditional P source assays and fieldhydrological monitoring for the site. Differences in simulated and observed outflowand SRP export are partially explained byforest evapotranspiration and frozen soilprocesses. The field data, SRP budgets andsimulations show that sufficient residual Ppools exist to prolong net SRP loss rates untilecosystem processes re-establish moreconservative P cycling.     

The development and effects of nitrogen deficiency in field-grown kiwifruit (Actinidia deliciosa) vines

The development and effects of nitrogen (N) deficiency in kiwifruit (Actinidia deliciosa Hayward) vines planted at three densities (25.0, 12.5 and 8.33 m² vine^–1) were examined in a long term (1982 to 1989) field experiment in which N was applied at rates from 0 to 200 kg N ha^–1 year^–1. The rate of applied N significantly affected leaf N concentrations every year from 1985 onwards, and the average leaf N concentrations declined throughout the experiment. Fruit N concentrations varied significantly with the level of applied N as early as 1986. The average fruit N concentrations varied strongly between years, and were inversely proportional to the fruit number (per m²), indicating that, after fruit set, growth of individual fruit was relatively insensitive to the vine N status. Effects of N supply on fruit yields resulted mostly from changes in fruit number (per m²). For vines planted at the high density, fruit yields responded significantly to the level of applied N each season from 1986 onwards. In any year, maximum fruit yields for vines planted at the high density were associated with leaf N concentrations (20 weeks after bud burst) of at least 1.8 mmol g^–1. For vines planted at low density, significant yield responses to the level of applied N were not recorded until 1988, and maximum yields in that year were associated with leaf N concentrations of at least 1.4 mmol g^–1. The delayed expression of effects of N deficiency on fruit yields for vines planted at low density appeared to follow a shift in partitioning of resources in favour of fruit growth. This shift in partitioning did not appear to be sustainable, and by 1989 the fruit yield response to applied N continued to the highest N level tested. In that year, the leaf N concentration associated with maximum yield was 1.8 mmol g^–1, the same as that recorded throughout the experiment for the vines planted at high density. In the last two seasons of the experiment, leaf necrosis developed extensively on vines receiving less than the highest rate of N. This necrosis appeared to be premature senescence resulting from N deficiency. Leaf chloride (Cl) concentrations increased significantly with increasing severity of N deficiency, but were never more than those associated with Cl toxicity. While N supply significantly affected fruit firmness immediately post-harvest, there were no significant effects on fruit firmness after 12–20 weeks storage.     

Experimental studies of rapid bioerosion of coral reefs in the Galápagos Islands

Experimental carbonate blocks of coral skeleton,Porites lobata (PL), and cathedral limestone (LS) were deployed for 14.8 months at shallow (5–6 m) and deep (11–13m) depths on a severely bioeroded coral reef, Champion Island, Galápagos Islands, Ecuador. Sea urchins (Eucidaris thouarsii) were significantly more abundant at shallow versus deep sites.Porites lobata blocks lost an average of 25.4 kg m^–2yr^–1 (23.71 m^–2yr^–1 or 60.5% decrease yr^–1). Losses did not vary significantly at depths tested. Internal bioeroders excavated an average of 2.6 kg m^–2 yr^–1 (2.41 m^–2 yr^–1 or 0.6% decrease yr^–1), while external bioeroders removed an average of 22.8 kg m^–2 yr^–1). (21.31 m^–2 yr^–1). or 59.9% decrease yr^–1). few encrusting organisms were observed on the PL blocks. Cathedral limestone blocks lost an average of 4.1 kg m^–2 yr^–1). (1.81 m^–2 yr^–1). or 4.6% decrease yr-'), also with no relation to depth. Internal bioeroders excavated an average of 0.6 kg m^–2 yr^–1). (0.31 m^–2 yr^–1). or 0.7% decrease yr^–1). and external bioeroders removed an average of 3.5 kg m^–2 yr^–1). (1.51 m^–2 yr^–1). or 3.9% decrease yr^–1). from the LS blocks. Most (57.6%) encrustation occurred on the bottom of LS blocks, and there was more accretion on block bottoms in deep (61.4 mg cm^–2 yr^–1). versus shallow (35.0 mg cm^–2 yr^–1) sites. External bioerosion reduced the average height of the reef framework by 0.2 cm yr^–1). for hard substrata (represented by LS) and 2.3 cm yr^–1). for soft substrata (represented by PL). The results of this study suggest that coral reef frameworks in the Galápagos Islands are in serious jeopardy. If rates of coral recruitment do not increase, and if rates of bioerosion do not decline, coral reefs in the Galápagos Islands could be eliminated entirely.     

Energy expenditure in relation to activity of lesser mouse deer (Tragulus javanicus)

Heat production (HP) of male and female mouse deer during eating, standing and sitting was determined using the open circuit respiration chamber (RC). The time taken for similar activities was also determined in an outdoor enclosure (OD). The animals were fed kangkong (Ipomoea aquatica), sweet potato (Ipomoea batatas) and rabbit pellet ad libitum. Male mouse deer consumed more dry matter (DM), organic matter (OM) and gross energy (GE) than female. The time for each activity of male and female mouse deer kept in RC and OD was similar. The average time spent in RC and OD for both male and female, respectively, for sitting (956 and 896 min/day) was significantly (P<0.01) longer than standing (463 and 520 min/day) and eating (21 and 24 min/day). Heat production for male and female mouse deer, respectively, during eating was the highest (0.44 and 0.43 kJ/kg W^0.75/min) followed by standing (0.37 and 0.33 kJ/kgW^0.75/min) and sitting (0.26 and 0.26 kJ/kg W^0.75/min). The difference in HP per min during standing between male and female was significant (P<0.05). The HP for 08.00–14.00 h and 14.00–20.00 h periods were higher than 20.00–02.00 h and 02.00–08.00 h periods. The overall HP for males during 08.00–14.00 h and 14.00–20.00 h periods were significantly (P<0.05) higher (114.8 and 119.2 kJ/kg W^0.75) than female (107.5 and 110.4 kJ/kg W^0.75), respectively.