التعريف: There is no evidence that the organism produces compounds (allelochemicals) that influence the growth, survival, and reproduction of other organisms.
التعريف: The percentage of organic carbon divided by the percentage of total nitrogen in organic material is higher than 59.
التعليق: USDA Plants database specifies the organic material as either the above ground biomass of an herbaceous plant or the above ground herbaceous material of a woody plant.
التعريف: A color hue with medium wavelength of that portion of the visible spectrum lying between orange and green, evoked in the human observer by radiant energy with wavelengths of approximately 570 to 590 nanometers.
التعريف: A porosity quality inhering in a bearer by virtue of the bearer's being capable of admitting the passage of gas or liquid through pores or interstices. (or, as in fungi, solids such as spores may be admitted through pores in the hymenium, for example)
التعريف: A porosity quality inhering in a bearer by virtue of the bearer's being capable of admitting the passage of gas or liquid through pores or interstices. (or, as in fungi, solids such as spores may be admitted through pores in the hymenium, for example)
التعريف: a fruit which develops from a carpel or gyneocium and at maturity comprises a dry exocarp, a dry mesocarp, and a dry endocarp that are connected to a seed coat by a funicle
التعريف: An area of land of low topographic relief that historically supported grasses and herbs, with few trees, and having generally a mesic (moderate or temperate) climate. Dominated by tall grasses (contrast steppe).
التعريف: A group of hydrous aluminium phyllosilicate (phyllosilicates being a subgroup of silicate minerals) minerals (see clay minerals), that are typically less than 2micrometres in diameter. Clay consists of a variety of phyllosilicate minerals rich in silicon and aluminium oxides and hydroxides which include variable amounts of structural water.
التعريف: A landform that extends above the surrounding terrain in a limited area. A mountain is generally steeper than a hill, but there is no universally accepted standard definition for the height of a mountain or a hill although a mountain usually has an identifiable summit and a local relief of more than 300m.
التعريف: A color hue with medium-low wavelength of that portion of the visible spectrum lying between yellow and blue, evoked in the human observer by radiant energy with wavelengths of approximately 490 to 570 nanometers.
التعريف: Of plant duration, a plant whose life span extends over more than two growing seasons, c.f. annual, biennial, ephemeral, of flowering with respect to architecture, hapaxanthic, monocarpic, pleonanthic
التعريف: Arenosols are sandy soils, including both soils developed in residual sands after in situ weathering of usually quartz-rich sediments or rock, and soils developed in recently deposited sands such as dunes in deserts and beach lands.
التعريف: National Museum of Natural History, Smithsonian Institution (USNM), Washington, District of Columbia, USA.\r\nNMNH and USNM both refer to the National Museum of Natural History. Collections are associated with one or the other acronym. US, the US National Herbarium, is a collection within the National Museum of Natural History. URL for main institutional website, http://www.mnh.si.edu/rc/\r\nURL for institutional specimen catalog, http://collections.mnh.si.edu/
التعريف: National Museum of Natural History, Smithsonian Institution (USNM), Washington, District of Columbia, USA.\r\nNMNH and USNM both refer to the National Museum of Natural History. Collections are associated with one or the other acronym. US, the US National Herbarium, is a collection within the National Museum of Natural History. URL for main institutional website, http://www.mnh.si.edu/rc/\r\nURL for institutional specimen catalog, http://collections.mnh.si.edu/
التعريف: National Museum of Natural History, Smithsonian Institution (USNM), Washington, District of Columbia, USA.\r\nNMNH and USNM both refer to the National Museum of Natural History. Collections are associated with one or the other acronym. US, the US National Herbarium, is a collection within the National Museum of Natural History. URL for main institutional website, http://www.mnh.si.edu/rc/\r\nURL for institutional specimen catalog, http://collections.mnh.si.edu/
التعريف: Museum National d'Histoire Naturelle (MNHN), Paris, France. URL for main institutional website: http://www.mnhn.fr/museum/foffice/science/science/sommaire.xsp
