VaguenessIn linguistics and philosophy, a vague predicate is one which gives rise to borderline cases. For example, the English adjective "tall" is vague since it is not clearly true or false for someone of middling height. By contrast, the word "prime" is not vague since every number is definitively either prime or not. Vagueness is commonly diagnosed by a predicate's ability to give rise to the Sorites paradox. Vagueness is separate from ambiguity, in which an expression has multiple denotations.
SilvicultureSilviculture is the practice of controlling the growth, composition/structure, as well as quality of forests to meet values and needs, specifically timber production. The name comes from the Latin silvi- ('forest') and culture ('growing'). The study of forests and woods is termed silvology. Silviculture also focuses on making sure that the treatment(s) of forest stands are used to conserve and improve their productivity. Generally, silviculture is the science and art of growing and cultivating forest [crops], based on a knowledge of silvics .
Ecological engineeringEcological engineering uses ecology and engineering to predict, design, construct or restore, and manage ecosystems that integrate "human society with its natural environment for the benefit of both". Ecological engineering emerged as a new idea in the early 1960s, but its definition has taken several decades to refine, its implementation is still undergoing adjustment, and its broader recognition as a new paradigm is relatively recent.
Hydraulic miningHydraulic mining is a form of mining that uses high-pressure jets of water to dislodge rock material or move sediment. In the placer mining of gold or tin, the resulting water-sediment slurry is directed through sluice boxes to remove the gold. It is also used in mining kaolin and coal. Hydraulic mining developed from ancient Roman techniques that used water to excavate soft underground deposits. Its modern form, using pressurized water jets produced by a nozzle called a "monitor", came about in the 1850s during the California Gold Rush in the United States.
PrimordiumA primordium (praɪˈmɔːrdiəm; : primordia; synonym: anlage) in embryology, is an organ or tissue in its earliest recognizable stage of development. Cells of the primordium are called primordial cells. A primordium is the simplest set of cells capable of triggering growth of the would-be organ and the initial foundation from which an organ is able to grow. In flowering plants, a floral primordium gives rise to a flower.
PhototropismIn biology, phototropism is the growth of an organism in response to a light stimulus. Phototropism is most often observed in plants, but can also occur in other organisms such as fungi. The cells on the plant that are farthest from the light contain a hormone called auxin that reacts when phototropism occurs. This causes the plant to have elongated cells on the furthest side from the light. Phototropism is one of the many plant tropisms, or movements, which respond to external stimuli.
Missouri RiverThe Missouri River is the longest river in the United States. Rising in the Eastern Centennial Mountains of the Bitteroot Range of the Rocky Mountains of Southwestern Montana, the Missouri flows east and south for before entering the Mississippi River north of St. Louis, Missouri. The river drains a sparsely populated, semi-arid watershed of more than 500,000 square miles (1,300,000 km2), which includes parts of ten U.S. states and two Canadian provinces.
Herbaceous plantHerbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials. The fourth edition of the Shorter Oxford English Dictionary defines "herb" as: "A plant whose stem does not become woody and persistent (as in a tree or shrub) but remains soft and succulent, and dies (completely or down to the root) after flowering"; "A (freq. aromatic) plant used for flavouring or scent, in medicine, etc.".
Threatened speciesThreatened species are any species (including animals, plants and fungi) which are vulnerable to extinction in the near future. Species that are threatened are sometimes characterised by the population dynamics measure of critical depensation, a mathematical measure of biomass related to population growth rate. This quantitative metric is one method of evaluating the degree of endangerment.
Ecosystem diversityEcosystem diversity deals with the variations in ecosystems within a geographical location and its overall impact on human existence and the environment. Ecosystem diversity addresses the combined characteristics of biotic properties (biodiversity) and abiotic properties (geodiversity). It is a variation in the ecosystems found in a region or the variation in ecosystems over the whole planet. Ecological diversity includes the variation in both terrestrial and aquatic ecosystems.