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Gymnostoma Intermedium
''Gymnostoma'' is a genus of about eighteen species of trees and shrubs, constituting one of the four genera of the plant family Casuarinaceae. The species grow naturally in the tropics, including at high elevations having temperate climates, in forests in the region of the western Pacific Ocean and Malesia. In New Caledonia, published botanical science describes eight species found growing naturally, which botanists have not found anywhere else (endemics). Other species are native to Borneo, Sumatra, Maluku, and New Guinea, and one endemic species each in Fiji and the Wet Tropics of Queensland, Australia. The genus was first scientifically described by Lawrie A. S. Johnson in 1980. Many of the ''Gymnostoma'' species combinations of names ( binomials) were described by him in 1982. , a global total of eighteen species have been found and described. The majority of the species grow in rainforests, in the habitats of open, sunny, long-term gaps, from river bank (riparian) situ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wet Tropics Of Queensland
The Wet Tropics of Queensland World Heritage Site consists of approximately 8,940 km2 of Australian wet tropical forests growing along the north-east Queensland portion of the Great Dividing Range. The Wet Tropics of Queensland meets all four of the criteria for World Heritage Site#Natural criteria, natural heritage for selection as a World Heritage Site. World Heritage status was declared in 1988, and on 21 May 2007 the Wet Tropics were added to the Australian National Heritage List. The tropical forests have the highest concentration of primitive flowering plant families in the world. Only Madagascar and New Caledonia, due to their historical isolation, have humid, tropical regions with a comparable level of endemism. The Wet Tropics rainforests are a biodiversity hotspot and recognised internationally for their ancient ancestry and many unique plants and animals. The area covers 0.1% of the Australian landmass but contains 50 per cent of all the nation's species. Many ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Plant List
The Plant List was a list of botanical names of species of plants created by the Royal Botanic Gardens, Kew and the Missouri Botanical Garden and launched in 2010. It was intended to be a comprehensive record of all known names of plant species over time, and was produced in response to Target 1 of the 2002–2010 Global Strategy for Plant Conservation (GSP C), to produce "An online flora of all known plants". It has not been updated since 2013, and has been superseded by World Flora Online. World Flora Online In October 2012, the follow-up project World Flora Online was launched with the aim to publish an online flora of all known plants by 2020. This is a project of the United Nations Convention on Biological Diversity, with the aim of halting the loss of plant species worldwide by 2020. It is developed by a collaborative group of institutions around the world response to the 2011-2020 GSPC's updated Target 1. This aims to achieve an online Flora of all known plants by 2020 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxisol
Oxisols are a soil order in USDA soil taxonomy, best known for their occurrence in tropical rain forest within 25 degrees north and south of the Equator. In the World Reference Base for Soil Resources (WRB), they belong mainly to the ferralsols, but some are plinthosols or nitisols. Some oxisols have been previously classified as laterite soils. Formation The main processes of soil formation of oxisols are weathering, humification and pedoturbation due to animals. These processes produce the characteristic soil profile. They are defined as soils containing ''at all depths'' no more than ten percent weatherable minerals, and low cation exchange capacity. Oxisols are always a red or yellowish color, due to the high concentration of iron(III) and aluminium oxides and hydroxides. They also contain quartz and kaolin, plus small amounts of other clay minerals and organic matter. Etymology The word "oxisol" comes from ''"oxide"'' in reference to the dominance of oxide mineral ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hardpan
In soil science, agriculture and gardening, hardpan or soil pan is a dense layer of soil, usually found below the uppermost topsoil layer. There are different types of hardpan, all sharing the general characteristic of being a distinct soil layer that is largely impervious to water. Some hardpans are formed by deposits in the soil that fuse and bind the soil particles. These deposits can range from dissolved silica to matrices formed from iron oxides and calcium carbonate. Others are man-made, such as hardpan formed by compaction from repeated plowing, particularly with moldboard plows, or by heavy traffic or pollution. Formations Soil structure strongly affects its tendency to form a hard pan. One such common soil condition related to hardpan is soil pH. Acidic soils are most often affected due to the propensity of certain mineral salts, most notably iron and calcium, to form hard complexes with soil particles under acidic conditions. Another major determinant is the soil partic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Base Saturation
Cation-exchange capacity (CEC) is a measure of how many cations can be retained on soil particle surfaces. Negative charges on the surfaces of soil particles bind positively-charged atoms or molecules (cations), but allow these to exchange with other positively charged particles in the surrounding soil water. This is one of the ways that solid materials in soil alter the chemistry of the soil. CEC affects many aspects of soil chemistry, and is used as a measure of soil fertility, as it indicates the capacity of the soil to retain several nutrients (e.g. K+, NH4+, Ca2+) in plant-available form. It also indicates the capacity to retain pollutant cations (e.g. Pb2+). Definition and principles Cation-exchange capacity is defined as the amount of positive charge that can be exchanged per mass of soil, usually measured in cmolc/kg. Some texts use the older, equivalent units me/100g or meq/100g. CEC is measured in moles of electric charge, so a cation-exchange capacity of 10 cmolc/kg co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allotropes Of Iron
At atmospheric pressure, three allotropic forms of iron exist, depending on temperature: alpha iron (α-Fe, ferrite), gamma iron (γ-Fe, austenite), and delta iron (δ-Fe, similar to alpha iron). At very high pressure, a fourth form exists, epsilon iron (ε-Fe, hexaferrum). Some controversial experimental evidence suggests the existence of a fifth high-pressure form that is stable at very high pressures and temperatures. The phases of iron at atmospheric pressure are important because of the differences in solubility of carbon, forming different types of steel. The high-pressure phases of iron are important as models for the solid parts of planetary cores. The inner core of the Earth is generally assumed to consist essentially of a crystalline iron-nickel alloy with ε structure. The outer core surrounding the solid inner core is believed to be composed of liquid iron mixed with nickel and trace amounts of lighter elements. Standard pressure allotropes Alpha iron (α-Fe) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laterite
Laterite is a soil type rich in iron and aluminium and is commonly considered to have formed in hot and wet tropical areas. Nearly all laterites are of rusty-red coloration, because of high iron oxide content. They develop by intensive and prolonged weathering of the underlying parent rock, usually when there are conditions of high temperatures and heavy rainfall with alternate wet and dry periods. The process of formation is called laterization. Tropical weathering is a prolonged process of chemical weathering which produces a wide variety in the thickness, grade, chemistry and ore mineralogy of the resulting soils. The majority of the land area containing laterites is between the tropics of Cancer and Capricorn. Laterite has commonly been referred to as a soil type as well as being a rock type. This, and further variation in the modes of conceptualizing about laterite (e.g. also as a complete weathering profile or theory about weathering), has led to calls for the term to be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Massif
A massif () is a principal mountain mass, such as a compact portion of a mountain range, containing one or more summits (e.g. France's Massif Central). In mountaineering literature, ''massif'' is frequently used to denote the main mass of an individual mountain. As a purely scientific term in geology, however, a "massif" is separately and more specifically defined as a section of a planet's crust (geology), crust that is demarcated by geologic fault, faults or lithospheric flexure, flexures. In the plate tectonics, movement of the crust, a massif tends to retain its internal structure while being displaced as a whole. A massif is a smaller structural unit than a tectonic plate and is considered the fourth-largest driving force in geomorphology. The word "massif" originates from French (in which the word also means "massive"), where it is used to refer to a large mountain mass or compact group of connected mountains forming an independent portion of a range. The Cydonia (regi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultramafic
Ultramafic rocks (also referred to as ultrabasic rocks, although the terms are not wholly equivalent) are igneous and meta-igneous rocks with a very low silica content (less than 45%), generally >18% MgO, high FeO, low potassium, and are usually composed of greater than 90% mafic minerals (dark colored, high magnesium and iron content). Earth's mantle is composed of ultramafic rocks. Ultrabasic is a more inclusive term that includes igneous rocks with low silica content that may not be extremely enriched in Fe and Mg, such as carbonatites and ultrapotassic igneous rocks. Intrusive ultramafic rocks Intrusive ultramafic rocks are often found in large, layered ultramafic intrusions where differentiated rock types often occur in layers. Such cumulate rock types do not represent the chemistry of the magma from which they crystallized. The ultramafic intrusives include the dunites, peridotites and pyroxenites. Other rare varieties include troctolite which has a greater pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inceptisol
Inceptisols are a soil order in USDA soil taxonomy. They form quickly through alteration of parent material. They are more developed than Entisols. They have no accumulation of clays, iron oxide, aluminium oxide or organic matter. They have an ochric or umbric horizon and a cambic subsurface horizon. In the World Reference Base for Soil Resources (WRB), most Inceptisols are Cambisols or Umbrisols. Some may be Nitisols. Many Aquepts belong to Gleysols and Stagnosols. Suborders * Aquepts – with a water table close to the surface *Anthrepts In the USDA soil taxonomy, Anthrepts is a term for soil with evidence of human habitation and farming. See also *Anthrosols in the World Soil Classification. *Inceptisols of which anthrepts are a suborder of. References {{reflist Types of so ... – with a plaggen or anthropic epipedon, a sign of intense and prolonged human activity * Gelepts – in very cold climates * Cryepts – in cold climates * Udepts – in humid clima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serpentine Soil
Serpentine soil is an uncommon soil type produced by weathered ultramafic rock such as peridotite and its metamorphic derivatives such as serpentinite. More precisely, serpentine soil contains minerals of the serpentine subgroup, especially antigorite, lizardite, and chrysotile or white asbestos, all of which are commonly found in ultramafic rocks. The term "serpentine" is commonly used to refer to both the soil type and the mineral group which forms its parent materials. Serpentine soils exhibit distinct chemical and physical properties and are generally regarded as poor soils for agriculture. The soil is often reddish, brown, or gray in color due to its high iron and low organic content. Geologically, areas with serpentine bedrock are characteristically steep, rocky, and vulnerable to erosion, which causes many serpentine soils to be rather shallow. The shallow soils and sparse vegetation lead to elevated soil temperatures and dry conditions. Due to their ultramafic origin, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
