Influx Of Minerals Research Articles

Mineral inputs, paleoecological change, and Holocene carbon accumulation at a boreal peatland in the Hudson Bay Lowlands, Canada

The Hudson Bay Lowlands (HBL) is a vast contiguous peatland extending over >370,000 km2 in Canada's boreal-subarctic, and is the traditional land of the Omushkego Cree. It is currently undergoing climatic warming alongside other anthropogenic stressors, and contains a large below-ground carbon pool. Understanding how climate variability and multiple stressors impact peat accumulation in this region is critical to discerning how northern peatlands will respond to future climate and land-use changes. Pollen- and macrofossil-based paleoecological reconstructions, and analyses of aluminum (Al) and titanium (Ti) fluxes in a Holocene-aged peat core (VM375) taken from a bog in the Attawapiskat watershed were conducted to link ecosystem changes with hydroclimate and long-term carbon storage. Peat initiation is dated to 5780 cal yr B.P., coincident with land emergence driven by glacial isostatic adjustment. From 4500 to 4200 cal yr B.P., apparent rate of carbon accumulation increased, and was linked to more rapid rates of peat accretion and increases in minerotrophic indicators in the pollen record. This increase in peat accretion and shift in vegetation composition co-occur with higher rates of mineral influx as shown by Ti and Al concentrations, which may have supplied nutrients. A fen to bog transition takes place ~3300 cal yr B.P., with increases in Sphagnum spores and macrofossils, and a decline in the apparent rate of carbon accumulation relative to the earlier half of the record, where paleoecological proxies indicate treed wetland and fen stages. Since peat inception, the total carbon stock of the 260-cm peat column is 110 kg C m−2. This multi-proxy record shows an association between changing peat types and variability in apparent rates of carbon accumulation, and supports the hypothesis that mineral nutrients either supplied by surface hydrology or by eolian deposition played a role in Holocene peat carbon accumulation in eastern North American boreal peatlands.

Ontogenetic development of the holocephalan dentition: Morphological transitions of dentine in the absence of teeth.

Among the cartilaginous fishes (Chondrichthyes), the Holocephali are unique in that teeth are absent both in ontogeny and adult regenerative growth. Instead, the holocephalan dentition of ever-growing nonshedding dental plates is composed of dentine, trabecular in arrangement, forming spaces into which a novel hypermineralized dentine (whitlockin) is deposited. These tissue features form a variety of specific morphologies as the defining characters of dental plates in the three families of extant holocephalans. We demonstrate how this morphology changes through ontogenetic development with continuity between morphologies, through successive growth stages of the dentition represented by the dental plate. For example, rod-shaped whitlockin appears early, later transformed into the tritoral pad, including a regular arrangement of vascular canals and whitlockin forming with increasing mineralization (95%-98%). While the tritoral pads develop lingually, stacks of individual ovoids of whitlockin replace the rods in the more labial parts of the plate, again shaped by the forming trabecular dentine. The ability to make dentine into new, distinctive patterns is retained in the evolution of the Holocephali, despite the lack of teeth forming in development of the dentition. We propose that developmentally, odontogenic stem cells, retained through evolution, control the trabecular dentine formation within the dental plate, and transition to form whitlockin, throughout lifetime growth. Our model of cellular activity proposes a tight membrane of odontoblasts, having transformed to whitloblasts, that can control active influx of minerals to the rapidly mineralizing dentine, forming whitlockin. After the reduced whitloblast cells transition back to odontoblasts, they continue to monitor the levels of minerals (calcium, phosphate and magnesium) and at a slower rate of growth in the peritubate 'softer' dentine. This model explains the unique features of transitions within the holocephalan dental plate morphology.

Distinct phases of natural landscape dynamics and intensifying human activity in the central Kenya Rift Valley during the past 1300 years

Socio-ecological stresses currently affecting the semi-arid regions of equatorial East Africa are driving environmental changes that need to be placed in a proper context of long-term human-climate-landscape interaction. Here we present a detailed reconstruction of past human influences on the landscape of the central Kenya Rift Valley, against the backdrop of natural climate-driven ecosystem dynamics over the past 1300 years. Proxy records of vegetation dynamics (pollen), animal husbandry (fungal spores), biomass burning (charcoal) and soil mobilization (clastic mineral influx) extracted from the continuous depositional archive of Lake Bogoria reveal six distinct phases of human activity. From ca 700 to 1430 CE, strong primary response of savanna woodland ecotonal vegetation to climatic moisture-balance variation suggests that anthropogenic influence on regional ecosystem dynamics was limited. The first unambiguous ecological signature of human activities involves a mid-15th century reduction of woodland/forest trees followed by the appearance of cereal pollen, both evidence for mixed farming. From the mid-17th century, animal husbandry became a significant ecological factor and reached near-modern levels by the mid-19th century, after severe early-19th century drought had substantially changed human-landscape interaction. A short-lived peak in biomass burning and evidence for soil mobilization in low-lying areas of the Bogoria catchment likely reflects the known 19th-century establishment of irrigation agriculture, while renewed expansion of forest and woodland trees reflect the return of a wetter climate and abandonment of other farmland. Since the mid-20th century, the principal signature of human activity within the Lake Bogoria catchment is the unprecedented increase in clastic sediment flux, reflecting widespread soil erosion associated with rapidly intensifying land use.

The relationships between some soil characteristics and abundance of arbuscular mycorrhizal fungi spores

Arbuscularmycorrhizae (AM) are important for plant growth and nutrition since they increase mineral influx. Mycorrhizal association plays a key role in the sustainability of terrestrial plant ecosystems, in particular those presenting limitations for the establishment and subsequent growth of plants. However, symbiosis efficiency is affected by many environmental factors. Studies conducted on the number of mycorrhizae in volcanic soils are very limited around the world and there are not any studies conducted in Iran. For this purpose, a study was carried out on soils with volcanic material in northwest of Iran. In this study, 21 horizons were defined in four different profiles with andesitic parent material. The total number of mycorrhizae existing in the horizons determined in a total of 4 profiles, that two of them located in pasture and two in garden areas. It was found out that the number of spores in garden areas was more than the number of spores in pastures. This was attributed to the fact that the existence of plant roots in garden areas was higher compared to pastures. In each profile, the highest number of mycorrhizal spores was obtained from different depths of horizon A, where ventilation is high, and the number of mycorrhizal spores showed a decrease as the depth increased. The correlation carried out in the study also revealed a negative relationship between the number of spores and horizon depth for all values and a positive relationship between the number of spores and organic matter.

Across the Mongolian Steppes

Across the Mongolian Steppes

Sensitivity of bulk sedimentary stable carbon isotopes to prehistoric forest clearance and maize agriculture

The stable carbon isotope compositions (δ 13C) of tropical lake sediments and soils have been used to reconstruct the occurrence of prehistoric maize cultivation and its relative importance through time. This study assesses some of the possible variables affecting the response of lake sediment bulk organic carbon isotope (δ 13C TOC) values to variations in the scale of prehistoric maize cultivation and the potential of this proxy to yield quantitative estimates of the scale of prehistoric maize agriculture in small tropical watersheds. High resolution analyses of δ 13C TOC values, maize pollen concentrations, and mineral influx were conducted on sediments deposited during a ∼220 year period of prehistoric maize agriculture in the watershed of Laguna Castilla, a small lake in the mid-elevations of the Cordillera Central, Dominican Republic. Close correspondence between δ 13C TOC values and maize pollen concentrations in the Laguna Castilla sediment record indicates a close relationship between the isotopic values and the scale of prehistoric maize cultivation. Correlations between the δ 13C TOC signature and mineral influx indicate that the isotope record is also sensitive to variations in allochthonous carbon delivery. This study establishes that sedimentary δ 13C TOC values can provide a highly sensitive proxy of the spatial scale of prehistoric maize agriculture in small tropical watersheds, but emphasizes the need for a better understanding of sediment dynamics and carbon cycling in anthropogenically modified landscapes before this proxy can be widely employed in diverse archaeological settings.

The effect of different soil properties on arbuscular mycorrhizal colonization of peanuts, sorghum and maize

Arbuscular mycorrhizal fungi (AMF) are important for plant growth since they increase mineral influx. However, symbiosis efficiency is affected by many environmental factors. This study evaluated the effects of different treatments (+/- phosphorus; +/- liming; +/- organic matter; field, sandy or clayey soil textures) on root colonization (RC) of peanuts, sorghum and maize. The combination of these resulted in seventy-two treatments. The 2×2×2×3×3 factorial experiment was laid out in a randomized design. All data were subjected to variance analysis and the means were compared (Tukey at P<0.05). Three months after seed germination, roots were collected to evaluate the percentage of RC. Results showed that soil texture and liming were the most important factors influencing colonization percentage in maize, sorghum and peanuts by AMF. Significant differences were also observed between the phytobionts. Organic matter (OM) had very little influence and phosphorus addition had no effect on RC.

Le marais estuarien de la Songolo (Sud Congo) a l'Holocene moyen et recent

Abstract This paper presents the most recent and detailed Holocene palynological research carried out on the Congolese Atlantic littoral, in the region of Pointe-Noire, as part of the ECOFIT program (CNRS-IRD). The results are obtained on two continental sedimentary sequences (core S2 from Songolo site: 4 degrees 45'51"S, 11 degrees 51'55"E, alt. 5 m and core 2 from Coraf site: 4 degrees 45'S, 11 degrees 51'E, alt. 1 m). Pollen data and interpretation are completed on the Songolo sequence by mineralogical (quartz, kaolinite, TOM) and isotopic (delta 13 C on organic matter) analysis allowing a continuous reconstruction of the Congolese littoral palaeoenvironments from 7000 yr. cal B.P. onwards. The Congolese coastal plain is today a mosaic of forest-grassland. Sandy open short savanna largely occurs with as dominant grass Loudetia arundinacea. Locally, Symphonia globulifera swamp forests are present along rivers and in flooded areas. Mangrove with Rhizophora is not well developed except along the Kouilou estuarine. The climate is characterized by mean annual precipitation not exceeding 1300 mm and temperature ranging between 22 and 25 degrees C. The core S2 from Songolo site was extracted using a piston corer. The coring site is today a peat building swamp with abundant Cyperus papyrus. The local dominant trees are Raphia and Alstonia. The presence of Elaeis guineensis (oil palm) and Mangifera indica (mango) testifies of a recent human occupation of this area. The core Coraf 2 was collected on the beach by manual penetration of PVC tube. On the two studied cores, dating control is provided by thirteen 14 C conventional and AMS dates performed on total organic matter. The ages are reported with equivalent ranges in calendar years. The present pollen, mineralogical and isotopic records, completed by previous other data (mainly macroflora remains), give new informations on vegetation and hydrological changes at local and regional scale since 7000 yr. cal B.P. on the Congolese littoral, in relation to climatic and sea level changes. The main conclusions can be summarized as follows. During the middle Holocene (7000-3000 yr. cal B.P.), expansion of swamp dense forests with Pandanus, Anthostema, Hallea, Symphonia globulifera, Syzygium, and also of mangrove (Rhizophora), as testified by pollen analysis, gives evidence of high rainfall which is also supported at Songolo by the abundance of kaolinite and quartz, an increase in the amorphous silica and delta 13 C low values typical of C 3 biomasse until 3000 yr. cal. B.P. At the same time, the occurrence in macroflora remains of trees such as Saccoglottis gabonensis, Ongokea gore and several species of Monopetalanthus that are found today in the Mont de Cristal forest in Gabon, under 2000-2500 mm of annual rainfall, confirms this climatic interpretation. A major change is registered ca. 3000 yr. cal B.P., characterized by the regression of the swamp forests which are replaced by herbaceous formations dominated by Cyperaceae and ferns, the disappearance of mangrove near the Songolo site, an important decrease in mineral influx (quartz and kaolinite) and increase in organic matter content. Increase in delta 13 C values during this period shows that most of the organic fraction derives from C 4 plants, probably linked to local expansion of Cyperus papyrus. This change, well known at this time on several sites from Central Atlantic Africa, is mainly linked to a progressive regional deterioration of climate towards aridity. On the Songolo site, the presence of fresh water taxa such as Nymphaea lotus supports an absence of marine water influence, indicating a sea level regressive episode well known, at the same time, along the West African coast. During the most recent period, despite more favourable climatic conditions (rainfall), no re-extension of littoral swamp forests is detected. These results are mainly related to the location of the studied sites, in an area of particularly intense human impact as shown by the occurrence of Elaeis guineensis (oil palm) in macroflora remains recovered from numerous archeological sites. The multidisciplinary data presented here correlate well with previous records from Central Atlantic Africa (Congo and Cameroon). The general similarity of the registered changes during the last 7000 yr cal B.P. strongly supports a regional climatic interpretation.

Mineralization of alkaline phosphatase-complexed collagen implants in the rat in relation to serum inorganic phosphate

The present study was designed to determine the relationship between mineralization of collagenous matrices and serum levels of calcium and inorganic phosphate. Collagen slices were prepared from bovine dentin or cortical bone and complexed with varying amounts of intestinal alkaline phosphatase (ALP). The enzyme was added to induce de novo mineralization. The ALP-complexed slices were implanted subcutaneously over the skull and in the dorsolateral aspect of the abdominal wall in female Wistar rats of various ages (5-, 10-, 20-, or 35-week-old) and in young male rats fed on a low-P diet. After 1-4 weeks, the implants were removed and analyzed for calcium and phosphate content. In addition, serum levels of calcium and phosphate (total and inorganic) were determined. It was shown that the highest mineral influx occurred in the younger rats (which were also highest in serum P(i)), whereas almost no mineral uptake occurred in the older ones. Also in rats fed on a low-P diet (which were low in serum P(i), a strongly decreased mineral influx was noted. In all animal groups a positive correlation was found between the degree of mineralization and serum P(i). No distinct relationship was found between serum Ca/organic phosphate levels and mineral influx in the implants. In vitro incubation of ALP-collagen conjugates in serum from younger and older rats confirmed our view that serum P(i), besides local levels of ALP, is important in de novo mineral deposition. For accretion of mineral in partially remineralized collagenous carriers, ALP activity was not required.

Mineralization of alkaline phosphatase‐complexed collagenous implants in the rat: Relation with age, sex, and site of implantation

This study was designed to determine the effects of age, sex, and site of implantation on the extent of alkaline phosphatase-complexed collagen sheets mineralization in the animal body. Collagen sheets were prepared from bovine dentin and cortical bone and complexed with varying amounts of intestinal alkaline phosphatase (ALP). Controls were without enzyme or with heat-inactivated enzyme. Sheets were implanted subcutaneously over the skull and in the dorsolateral abdominal wall in 5- or 20-week-old male and female Wistar rats. After 2-3 weeks the implants were removed and analyzed for phosphate and calcium content. Our findings have shown that alkaline phosphatase-induced mineralization of collagenous implants is influenced to a considerable extent by age, sex, and site of implantation. Highest mineral influx was seen in the younger males. Implants in younger females and older males contained less mineral, whereas those installed in the older females were almost free of calcium phosphate deposits. Dentinal implants in the skull region contained more mineral than those in the abdominal wall.

The Effect of Temperature on Growth and Mineral Nutrition of Fruits of Apple, with Special Reference to Calcium

AbstractGrowth and mineral composition of fruits in potted trees were studied at two temperatures (19 and 24°C) in two experiments with Golden Delicious and one with Cox's Orange Pippin under a controlled environment. In Golden Delicious the high temperature promoted fruit growth markedly, but in Cox's Orange Pippin the stimulation was much less pronounced.The levels of K, N, Mg, and P (expressed as amounts per fruit) were increased at the higher temperature. This increase was almost completely the result of differences in fruit growth. With respect to Ca the high temperature reduced Ca influx in one Golden Delicious experiment and had hardly any effect in the other, but favoured influx in Cox's Orange Pippin. In one Golden Delicious experiment the temperature was raised 7 weeks after blossoming, which resulted in a temporary drop of Ca. When the same temperature change was applied 4 weeks earlier, Ca continued to increase.It is assumed that mineral influx occurs via the xylem during the first few weeks after fruit set and via the phloem throughout. The results are discussed in terms of differences in mobility in the phloem for the various minerals and of a shift in the ratio between xylem and phloem movement induced by differences in the growth rate of the fruits.

THE INTRODUCTION OF DOMESTICATED REINDEER INTO ALASKA

THE INTRODUCTION OF DOMESTICATED REINDEER INTO ALASKA BY ARTHUR S.PETERSON The reindeer industry was originally conceived to be a native domestic industry for the welfare of a backward and primitive race, whose subsistence had been almost destroyed by the whites. That it served its purpose in providing for the Eskimo there can be no doubt. It also served to insure the relief of shipwrecked, icebound whalers in the Far North, and of distressed miners prospecting the outlands, although that was not the main reason for the hiring of Lapp herdsmen and the teaching of Eskimos to handle their herds.1 The introduction of reindeer into Alaska has changed the Eskimos from a nomadic to a pastoral people. "Its introduction ," said the late Secretary of the Interior Franklin K. Lane, " was the one constructive thing that the Government has done for the Eskimo natives in fifty years." 2 Credit for the introduction of domesticated reindeer into Alaska must go to Mr. William Thomas Lopp, chief of the Alaska division of the bureau of education. When asked how he happened to hit upon the idea, Mr. Lopp said, It was in 1890 during my first Winter's exile in the native village at Cape Prince of Wales that the idea of using reindeer as a means of food, clothing and transportation first suggested itself to me. . . . My mind went back to my geography lessons in school. Here I was, living in the same latitude as the Lapps, who, as I had learned in school, depended upon the reindeer for their livelihood. Naturally, the same climatic conditions suggested the feasibility of the reindeer industry in Alaska.3 1 Trumbull White, " Coming Storm over Alaska," in the New Outlook , 162:17 (August, 1933). 2 Marius Hansome, " The Eskimo and the Fourth * R,' " in Current History , 16:103 (April, 1922). Hansome, in Current History , 16: 103. 98 INTRODUCTION OF REINDEER 99 Captain M. A. Healy, who commanded the revenue cutter " Bear," transmitted the idea to Dr. Sheldon Jackson. He in turn requested Congress to provide funds for buying Siberian reindeer. This request was ultimately met, and " in 1892 a herd of 170 reindeer was brought over from Siberia to Port Clarence." Following this delivery, regular shipments were made for a decade. Ivan Petroff, Alaskan census enumerator in 1890, said that the scheme would not be successful, that it would be hard to make herders out of the Eskimo hunters, and that the Eskimo dogs would kill the deer. Mr. Lopp was not discouraged, however, and, being familiar with the native tongues of the Eskimo people, he was able to appeal to their best instincts. He enlisted the most promising young men by convincing them of their responsibility and by awakening their ambition to leadership. As an incentive to their interest, he assured them that in due time they could expect a substantial reward.4 Dr. Sheldon Jackson, a pioneer Presbyterian missionary, deserves the lion's share of the credit for the actual success of the industry, for it was in him that the movement found a capable and energetic leader, who realized that the economic problems confronting the Eskimo tribes in Alaska had to be faced honestly if the people were to survive. At this time Major General A. W. Greely, long the superior authority in all Alaskan matters, said that unless the wholesale destruction of land game, the practical extinction of sea game, and the influx of miners were controlled, the extermination of thousands of natives by starvation was imminent . Realizing that the problem facing the Eskimo was one of gigantic proportions, Dr. Jackson began to work with a tireless enthusiasm which eventually began to bear results. Jackson made contacts with churches, mission boards, and benevolent individuals, until he raised $2,146.00 in supplies, 4 Hansome, in Current History , 16: 103. 100 STUDIES AND RECORDS not money, for barter was the only way to deal with the Siberian Eskimo across the Bering Straits from Alaska. In 1891, after several trips had been made into Siberia to buy reindeer, the quest was rewarded by the acquisition of several animals. These were transported to Alaska on the revenue cutter " Bear." Following the first success...