Management of basiphilous dune slack communities in relation to carbonate accumulation and hydrological conditions

In dune slacks in The Netherlands, a decline of rare mesotrophic basiphilous plant species and their plant communities has been observed in combination with an increase of more productive systems with common, taller acidophilous plant species. This has been attributed to both natural and anthropogenic changes. In a humid climate with a precipitation surplus, as in The Netherlands, the calcium carbonate content of a calcareous soil increases with depth. However, soils in coastal dune slacks, may have a higher carbonate content in the topsoil horizon than in the underlying layers. Carbonates which buffer the pH can prolong the presence of mesotrophic basiphilous plant communities which are of high conservation value. To explain the occurrence of calcareous surface horizons in dune slacks, hydrological and micromorphological analyses were carried out in three dune slacks. Two slacks are situated on the Wadden Sea islands in the northern part of The Netherlands; one on Schiermonnikoog and one on Texel. The third slack is situated in the dunes on the island of Goeree in the southwestern part of The Netherlands. In all three slacks, carbonate occurs as mollusc and gastropod fragments (silt- or sand-sized) and as micritic nodules in the topsoil layer, due to aeolian deposition and sedimentation by water.In situ carbonate accumulation (calcitans and calcareous crusts) due to CO₂ release in inundated and/or capillary rise of calcareous groundwater near, or at the soil surface. Accumulation of carbonate also occurs as a result of biological activity by algae in the topsoil of the Goeree site. In general, hydrological processes maintaining high levels of calcareous groundwater are a prerequisite for the maintenance of high carbonate levels in topsoils. Such levels are necessary for the conservation and management of basiphilous pioneer vegetation.     

The use of legumes for reclaiming copper mine wastes in the Southwestern USA

Seeds of three legumes, blue lupine (Lupinus hirsutus L.), sesbania (Sesbania macrocarpa Muhl.), and alfalfa (Medicago sativa L.) were broadcast planted on four soil materials (desert soil, overburden, overburden plus tailings, and tailings) associated with copper mines near Tucson, Arizona. Experiments were conducted to study the effects of the four soil materials on germination (emergence), seedling establishment, and growth over a two-year period (1974 and 1975). All species grew best on desert soil, followed by overburden, overburden plus tailings, and tailings, in decreasing order. The presence of copper in overburden plus tailings and in tailings may have created a toxicity effect that limited the growth of plants in these two soil materials. Alfalfa was superior on all soil materials. Sesbania and blue lupine grew equally well. All three species were able to adapt to the different soil materials. For revegetation on copper mine wastes, it is desirable to plant a variety of plant species rather than a single species, to help blend the disturbed areas into the surrounding environmentApproved for publication as Arizona Agricultural Experiment Station Research Contribution No. 3100.     

Salinity effects on glucose uptake and catabolism in the obligately psychrophilic marine bacterium Vibrio marinus

Studies on the effects of various salinities on the uptake and catabolism of glucose in Vibrio marinus MP-1 revealed several significant shifts in total uptake and respiration as the cells were subjected to increasingly greater concentrations of NaCl. As the salinity increased from 0.30 to 1.0 M NaCl, there was a decrease in the C₆/C₁ (CO₂) ratio. The resulting patterns suggests that the relative participation of the hexose monophosphate pathway in glucose catabolism was altered. This pathway is apparently shut down in the region of the minimum-growth salinity, and may be related to growth limitation at rower salinities. The shift in C₆/C₁ ratio was not affected by changing the incubation temperature, nor was it dependent specifically on the presence of Na⁺ or Cl^-. As the salinity increased from 0.15 to 0.30 M NaCl, there was a shift in the total uptake patterns which suggests the formation and loss of metabolic by-products derived from the first, second, sixth, and presumably fifth carbons of glucose.This paper was taken in part from a dissertation by the senior author, submitted in partial fulfillment of the requirement for the Ph.D. degree, Oregon State University, Corvallis. Published as technical paper No. 3647, Oregon Agricultural Experiment Station.     

Age specific maternal defense in Gargaphia solani (Hemiptera: Tingidae)

Summary It is predicted that the intensity of parental defense of offspring is a function of both the increasing reproductive value of offspring and the decreasing reproductive value of parents. The ontogeny of maternal defensive behavior in the lace bug Gargaphia solani is consistent with these predictions in that mothers become more aggressive as they age (between clutches) and also more aggressive as nymphs reach maturity (within clutches).Published with the approval of the Director of the Delaware Agricultural Experiment Station as Miscellaneous Paper No. 981, Contribution No. 513 of the Department of Entomology and Applied Ecology, University of Delaware, Newark, Delaware 19711, USA     

Evaluation of lime requirement tests for minesoils

Evaluation of twelve minesoils collected from restored or abandoned surface mines in eastern Kentucky with six standard lime requirement procedures showed that one of the procedures accurately forecasted long term lime requirements. The minesoils were then evaluated for potassium choloride-extractable aluminum using the Yang exchangeable acidity procedure. When the extractable A1³⁺ was multiplied by a factor of 2.24 it was found to also be an accurate measure for longterm limestone requirements. To bring the minesoil to pH 5.5 the results obtained using the modified Yuan procedure indicate that for each MEQ Al³⁺ extracted per 100 grams of minesoil 2.24 Mg of calcium carbonate (CaCO₃) equivalent lime per hectare be applied. Application of lime based on this procedure and one of the standard lime procedures resulted in pH stability of the minesoils for forty months.     

Tidal variations in the movement of organic carbon in New Jersey salt marshes

The movement of organic carbon was assessed by statistical and simulation modeling analyses in two marsh types in New Jersey;each marsh contained three water-drainage systems in which three tidal cycles were sampled in May and June 1973. Hourly water samples were obtained and filtered through a gelman Type A glass filter for separation into dissolved (DOC) and particulate (POC) organic carbon components of the total organic carbon (TOC). Simulation data showed that individual creeks and marshes functioned differently on the sampled tidal cycles in regard to net movement of water and organic carbon components. Organic carbon components exhibited similar tidal variations, with significantly lower concentrations at flood slack than at ebb slack. Mid-ebb concentrations were significantly higher than mid-flood concentrations for TOC and POC. Individual marshes showed significantly different concentrations in the latter segments of the tidal cycle for TOC's and POC's. Results indicate that individual creeks, marshes and tidal cycles are not representative of the total movement of organic carbon in estuaries.Paper of the Journal Series, New Jersey Agricultural Experiment Station, Cook College, rutgers—The state University of New Jersey, New Brunswick, New Jersey 08903, USA.     

Growth response of an early successional assemblage of coralline algae and benthic diatoms to ocean acidification

The sustained absorption of anthropogenically released atmospheric CO₂ by the oceans is modifying seawater carbonate chemistry, a process termed ocean acidification (OA). By the year 2100, the worst case scenario is a decline in the average oceanic surface seawater pH by 0.3 units to 7.75. The changing seawater carbonate chemistry is predicted to negatively affect many marine species, particularly calcifying organisms such as coralline algae, while species such as diatoms and fleshy seaweed are predicted to be little affected or may even benefit from OA. It has been hypothesized in previous work that the direct negative effects imposed on coralline algae, and the direct positive effects on fleshy seaweeds and diatoms under a future high CO₂ ocean could result in a reduced ability of corallines to compete with diatoms and fleshy seaweed for space in the future. In a 6-week laboratory experiment, we examined the effect of pH 7.60 (pH predicted to occur due to ocean acidification just beyond the year 2100) compared to pH 8.05 (present day) on the lateral growth rates of an early successional, cold-temperate species assemblage dominated by crustose coralline algae and benthic diatoms. Crustose coralline algae and benthic diatoms maintained positive growth rates in both pH treatments. The growth rates of coralline algae were three times lower at pH 7.60, and a non-significant decline in diatom growth meant that proportions of the two functional groups remained similar over the course of the experiment. Our results do not support our hypothesis that benthic diatoms will outcompete crustose coralline algae under future pH conditions. However, while crustose coralline algae were able to maintain their presence in this benthic rocky reef species assemblage, the reduced growth rates suggest that they will be less capable of recolonizing after disturbance events, which could result in reduced coralline cover under OA conditions.     

Temperate reefs in a changing ocean: skeletal carbonate mineralogy of serpulids

We present a review of the published data about serpulid skeletal carbonate geochemistry, augmented with new data from the Southern Hemisphere. We know something about skeletal carbonate mineralogy of 15 % of extant species (n = 52); and about half of extant genera (n = 25). Serpulid worm tubes vary in their skeletal mineralogy from entirely aragonitic (about 24 % of species) to entirely high-Mg calcite (40 %) to mixtures of the two. Mg in calcite ranges from 7 to 15 wt% MgCO₃, with a mean of 11 wt% MgCO₃. Little mineralogical variation within individuals or species can be found in aragonitic specimens, whereas high-Mg calcitic species show somewhat more variability in both calcite and Mg content, and those with mixed mineralogies are highly variable. These three groups correspond broadly with currently accepted clades. Given this strong phylogenetic signal, we analysed the data using phylogenetically independent contrasts, a statistical approach that separates genotypic from phenotypic variability; we found that variations which might be ascribed to environment were generally weak. The mineralogy of serpulid tubes makes them particularly vulnerable to ocean chemistry changes. While some serpulids appear to be able to adjust their tube mineralogy in order to adapt to sea-water chemistry, overall strength and elasticity may be sacrificed when they do. The biodiverse reef habitat provided by serpulids in some temperate regions may be the only complex solid habitat available, and loss or compromise of these temperate reefs will most likely have deleterious flow-on effects on temperate benthic communities.     

Catalytic activities and mechanism of formaldehyde oxidation over gold supported on MnO<Subscript>2</Subscript> microsphere catalysts at room temperature

MnO₂ microspheres with various surface structures were prepared using the hydrothermal method, and Au/MnO₂ catalysts were synthesized using the sol-gel method. We obtained three MnO₂ microspheres and Au/MnO₂ samples: coherent solid spheres covered with wire-like nanostructures, solid spheres with nanosheets, and hierarchical hollow microspheres with nanoplatelets and nanorods. We investigated the properties and catalytic activities of formaldehyde oxidation at room temperature. Crystalline structures of MnO₂ are the main factor affecting the catalytic activities of these samples, and γ-MnO₂ shows high catalytic performance. The excellent redox properties are responsible for the catalytic ability of γ-MnO₂. The gold-supported interaction can change the redox properties of catalysts and accelerate surface oxygen species transition, which can account for the catalytic activity enhancement of Au/MnO₂. We also studied intermediate species. The dioxymethylene (DOM) and formate species formed on the catalyst surface were considered intermediates, and were ultimately transformed into hydrocarbonate and carbonate and then decomposed into CO₂. A proposed mechanism of formaldehyde oxidation over Au/MnO₂ catalysts was also obtained.     

An ecophysiological study of some meiofauna species inhabiting a sandy beach at Bermuda

The dominant nematode and harpacticoid species inhabiting a sheltered beach at Bermuda were characterized by their vertical distribution in the sediment, by their tolerance of high temperature under oxic and anoxic conditions, and by their tolerance of extreme pH-values. In 4 species of nematodes the respiratory rate proved to be inversely proportional to the depth at which the species occurs, and directly proportional to the size of the buccal cavity. One species, the nematode Paramonhystera n.sp., is more temperature resistant at zero or near zero pO₂ than at atmospheric oxygen pressure; it is the first marine metazoan in which it can be shown that a specific biological process is favourably affected by anoxic conditions if compared with the situation at normal pO₂.Contribution No. 593, the Bermuda Biological Station     

岷江上游典型退化生态系统鸟类物种多样性的初步研究

在岷江上游典型的退化生态系统（十里乡）、逐渐恢复的生态系统（茂县生态站，1986年开始人工恢复）和原始森林及次生高山草甸生态系统（上卡卡沟）选择样地，对其乌类物种多样性在夏秋两季进行了调查，并计算其多样性指数和均匀度指数。各多样性指数的变化有微小差异，但总体一致。综合夏秋两季，茂县生态站夏季的鸟类丰富度、多度和多样性指数值最高，十里乡秋季的鸟类丰富度、多样性指数值最低，上卡卡沟秋季的均匀度指数最高。各群落的相似性指数较低，表明各群落组成有较大差异，拟合各样地鸟类的物种－多度曲线模型，十里乡鸟类的物种－多度模型与对数级数分布拟合，茂县鸟类的物种－多度模型与对数级数分布相似，上卡卡沟鸟类的物种－多度模型与分割线段模型分布拟合，夏秋季的物种－多度模型无明显差异，仅茂县的物种－多度模型与风何级数分布拟合，并对鸟类对生态恢复的监测效应进行了探讨，认为物种－多度模型是良好的生境变化生物指示因子，图3表4参19。     

生态系统数据管理中的数据文档文件

生态系统的数据结构不同于商用数据结构。本文参考美国ＬＴＥＲＮ的Ｓｅｖｉｌｌｅｔａ站生态系统的数据管理模式，结合中国科学院封丘农业生态实验站的实际情况，着重介绍了生态系统的数据文档文件的特点、结构和应用，而这些都是研究生态系统数据管理的最基础工作。     

Photographic and acoustic tracking observations of the behaviour of the grenadier Coryphaenoides (Nematonurus) armatus the eel Synaphobranchus bathybius,and other abyssal demersal fish in the North Atlantic Ocean

Using an autonomous free-fall vehicle (AU-DOS), observations were made of demersal fish attracted to baits and baited acoustic transmitters at two stations in the North Atlantic Ocean. A comparison was made between Station PAP (48°50N; 16°30W), 4800 m deep on the Porcupine Abyssal Plain which is relatively eutrophic, and Station MAP (31°N; 20°W), 4900 m deep on the Madeira Abyssal Plain, which is oligotrophic. Experiments were conducted during summer, in 1989 and 1990. Four species of fish were observed at Station MAP, the grenadier, Coryphaenoides (Nematonurus) armatus, the eel, Synaphobranchus bathybius, and the ophidiids Spectrunculus grandis, and Barathrites sp. At Station PAP, C. (N.) armatus and H. (S.) bathybius were attracted to bait on all deployments and only two other individuals of different species, probably ophidiids, were seen. The mean first grenadier arrival time was 30 and 138 min at Stations PAP and MAP, respectively. Mean first eel arrival time was 29 and 151 min at Stations PAP and MAP, respectively. Estimated population densities of fish were 167 grenadiers km^-2 and 180 synaphobranchid eels km^-2 at Station PAP and 8 grenadiers km^-2 and 7 eels km^-2 at Station MAP. Only the grenadier C. (N.) armatus definitely ingested transmitters, and this species dominated fish activity around the baits. Mean time of departure of grenadiers with transmitters in their stomachs across an acoustic horizon at 1000 m range was 371 and 488 min at Stations PAP and MAP, respectively. Grenadiers had a longer mean staying time at the food source at the more oligotrophic Station MAP (364 min) than at Station PAP (141 min). This corresponds with predictions of optimal foraging theory.     

Impacts of ocean acidification on marine shelled molluscs

Over the next century, elevated quantities of atmospheric CO₂ are expected to penetrate into the oceans, causing a reduction in pH (?0.3/?0.4 pH unit in the surface ocean) and in the concentration of carbonate ions (so-called ocean acidification). Of growing concern are the impacts that this will have on marine and estuarine organisms and ecosystems. Marine shelled molluscs, which colonized a large latitudinal gradient and can be found from intertidal to deep-sea habitats, are economically and ecologically important species providing essential ecosystem services including habitat structure for benthic organisms, water purification and a food source for other organisms. The effects of ocean acidification on the growth and shell production by juvenile and adult shelled molluscs are variable among species and even within the same species, precluding the drawing of a general picture. This is, however, not the case for pteropods, with all species tested so far, being negatively impacted by ocean acidification. The blood of shelled molluscs may exhibit lower pH with consequences for several physiological processes (e.g. respiration, excretion, etc.) and, in some cases, increased mortality in the long term. While fertilization may remain unaffected by elevated pCO₂, embryonic and larval development will be highly sensitive with important reductions in size and decreased survival of larvae, increases in the number of abnormal larvae and an increase in the developmental time. There are big gaps in the current understanding of the biological consequences of an acidifying ocean on shelled molluscs. For instance, the natural variability of pH and the interactions of changes in the carbonate chemistry with changes in other environmental stressors such as increased temperature and changing salinity, the effects of species interactions, as well as the capacity of the organisms to acclimate and/or adapt to changing environmental conditions are poorly described.     

Corallina and Ellisolandia (Corallinales,Rhodophyta) photophysiology over daylight tidal emersion: interactions with irradiance,temperature and carbonate chemistry

The photophysiology of three geniculate coralline algal species (Corallina officinalis, C. caespitosa and Ellisolandia elongata) was determined in intertidal rock pools in the south-west UK at Combe Martin (51°12′31N 4°2′19W) and Heybrook Bay (50°31′66N 4°11′41W), at the start, middle and end of summer (September 1 and 2) and winter (February 9 and 10) daylight tidal emersion periods, in relation to prevailing irradiance, temperature and carbonate chemistry conditions. Algal photophysiology was assessed from rapid light curves performed using pulse amplitude modulation fluorometry. Corallina and Ellisolandia experienced significant fluctuations in irradiance, temperature and carbonate chemistry over seasonal and tidal cycles. Rock pool carbonate chemistry was predictable (R ² = 0.82, P < 0.0001) by photodose (summed irradiance) plus water temperature, but not significantly related to photophysiology. In contrast, Corallina and Ellisolandia relative maximum electron transfer rate showed a significant negative relationship (R ² = 0.65, P < 0.0001) with irradiance plus water temperature. At a seasonal resolution, photoacclimation to maximize both light harvesting during winter months and photoprotection during summer months was observed for all species. Dynamic photoinhibition was apparent over both summer and winter tidal emersion, in relation to irradiance fluctuations. More effective photoinhibition was apparent during summer months, with greater sensitivity to irradiance and slower recovery in F _v/F _m, observed during winter. With sustained high irradiance over tidal emersion, the establishment of high pH/low inorganic carbon conditions may impact photochemistry. This study represents the first assessment of C. officinalis, C. caespitosa and E. elongata photophysiology underpinned by clear species concepts and highlights their ability to adapt to the dramatically fluctuating conditions experienced in intertidal rock pools.     

Effects of irrigation water qualities on biomass and sugar contents of sugar beet and sweet sorghum cultivars

An experiment involving four qualities of irrigation water two sugar beet and three sweet sorghum cultivars was conducted in a split plot design with four replications at Rudasht Drainage and Reclamation Experiment Station in 1999. The results showed salinity of water has an adverse effect on sugar beet and sweet sorghum biomass. Sweet sorghum cultivar SSV108 had the lowest biomass under all qualities of irrigation water Sweet sorghum cultivar Rio had the maximum biomass with water qualities of 2, 5, and 8 dS m(-1). Sugar beet cultivar 7233 had the maximum biomass with 11 dS m(-1). The effect of irrigation water quality was not significant for sugar characteristics such as brix, pol and purity. However, responses of cultivars on the above parameters were significant and sugar beet cultivars had higher brix, pol and purity and lower invert sugar and starch than sweet sorghum cultivars. In conclusion, sweet sorghum cultivars are not recommended to be irrigated with saline water of more than 8 dS m(-1) for sugar production. Under such condition, they may be suitable to be grown for forage purposes.     

Influence of some coral reef communities on the calcium carbonate budget of Tiahura reef (Moorea,French Polynesia)

The calcium carbonate budget of coral reefs is the result of the interaction of the processes of calcification and biological degradation, and is reflected in the chemical properties of the seawater overlying the reefs. A series of experiments at Moorea Island (French Polynesia) in 1988 monitored the diurnal and nocturnal variations in the chemical properties of seawater under field and laboratory conditions. Our results revealed that in the study area (Tiahura barrier reef flat), the calcium carbonate budget varied over space and time as a function of location in the water current. Two in-situ sites were investigated; one was situated 100 m from the algal crest of the barrier reef, the other 300 m further downstream. As a result of cumulative upstream events, the daily net calcification was ten times higher at the downstream (5.22 gm^-2 d^-1) than at the upstream (0.45 gm^-2 d^-1) site. The carbonate uptake by in situ Porites lobata in enclosures (8 kgm^-2 yr^-1) was ten times higher than the uptake by the whole community in the surrounding water (0.8 kgm^-2 yr^-1) and five times higher than that recorded for P. lobata in laboratory experiments (1.4 kgm^-2 yr^-1), where illumination levels were 10% of in situ levels. In laboratory experiments, the planktonic fraction of the seawater had no perceptible influence on the calcium carbonate budget. In the absence of bioeroders, living coral totally depleted the carbonate content of the seawater (3.7 gm^-2d^-1). Bioerosive organisms played an important role in restoring this calcium carbonate; e.g. sea urchins grazing on algal turf covering dead coral ingested CaCO₃ and released this as a carbonate powder (1.26 gm^-2d^-1); a form of carbonate which is extremely accessible to chemical dissolution.     

Photochemical reaction of peroxynitrite and carbon dioxide could account for up to 15 % of carbonate radicals generation in surface waters

The carbonate radical (CO ₃ ^?· ) is a photoinduced transient species occurring in surface waters. The carbonate radical can transform both natural compounds and xenobiotics. For instance, it can react with electron-rich substrates such as anilines, phenols and organic sulfur compounds. Here we used the APEX software to assess photochemical reactions, including the formation rates of transient species, based on water chemistry and depth, under summertime irradiation conditions. We found that the reaction between peroxynitrite and carbon dioxide is a potentially significant source of CO ₃ ^?· in sunlit surface waters, and could account for up to 10–15 % of the total CO ₃ ^?· formation. The peroxynitrite pathway to CO ₃ ^?· would be most significant at pH 7–8 and would be enhanced in waters with elevated nitrate and low alkalinity. Therefore, the proposed process could add to the known photochemical sources of CO ₃ ^?· in surface-water environments.     

Degradation of carbendazim by UV/H<Subscript>2</Subscript>O<Subscript>2</Subscript> investigated by kinetic modelling

The transformation of the fungicide carbendazim (methyl-2 benzimidazole carbamate) induced by hydroxyl radical generated by the UV photolysis of H₂O₂ has been studied in dilute aqueous solution. The efficient reaction of hydroxyl radicals with carbendazim led to the rapid degradation of carbendazim. The study of reaction kinetics yielded a second order rate constant of 2.2±0.3 10⁹ M⁻¹ s⁻¹ for HO^· radicals with carbendazim. This value is in agreement with a high reactivity of HO^· radicals with carbendazim. Most degradation products were identified by high performance liquid chromatography mass spectrometry (HPLC-MS). In the presence of hydrogenocarbonate and carbonate ions, hydroxyl radicals were quenched and in turn carbonate radicals CO₃ ^·− were formed. Carbonate radicals are indeed known to react efficiently with compounds containing electron-rich sites such as nitrogen or sulfur atoms. The use of a kinetic modelling software gave evidence for the occurrence of such reactions with carbendazim. The second order rate constant of carbonate radical with carbendazim was equal to 6±2 10⁶ M⁻¹ s⁻¹. Electronic Publication     

Dehydrogenases as tools in the study of marine sediments

A method is outlined for the measurement of NADH₂-dependent dehydrogenase activity in whole samples as well as in fractions of carbonate sediments. The method is based on extraction of enzyme activity with phosphate buffer containing 0.12% Triton X-100, dialysis, and a photometric assay which permits initial velocity determinations of the enzyme reaction under controlled conditions of pH, temperature, and substrate concentration. The dehydrogenases extracted from carbonate sediment of a subtropical beach at Bermuda are characterized by low K _m values (0.03 to 0.07 mM NADH₂/1), pH maxima around 8.5, and temperature maxima between 35° and 40°C. Their vertical distribution in the sediment agrees with what is known about the distribution of biomass on beaches of this type, maximum activity occurring in the topmost centimetre. Approximately 80 to 90% of the total electron transport activity is contained in the grain fraction, the remainder in the interstitial fraction of a sediment sample. From this it can be inferred that the interstitial fauna contributes only little to the total energy budget of this type of sediment, which is dominated by the Aufwuchs on the sand grains. The electron transport activity (ETA) measured by means of the dehydrogenase assay is taken to represent the maximum transport capacity (ETC) of all the organisms living in the sand ecosystem. From published evidence it is inferred that oxygen consumption of sediment samples and of individual organisms measured in vivo usually accounts for 10 to 20% of the maximum electron transport capacity measured in vitro with saturating concentrations of substrates and with Triton X-100 as part of the enzyme assay. It is suggested further that the ratios of dehydrogenase activities in different fractions or zones of sediment, or of different organisms, may represent one of the best indicators, so far available, of energy relationships in marine sediments.Contribution No. 652 from the Bermuda Biological Station for Research.