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Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class of soil or soil type; i.e., a soil containing more than 85 percent sand-sized particles by mass. [2]
Greensand or green sand is a sand or sandstone which has a greenish color. This term is specifically applied to shallow marine sediment that contains noticeable quantities of rounded greenish grains. These grains are called glauconies and consist of a mixture of mixed-layer clay minerals, such as smectite and glauconite. Greensand is also ...
Sand dunes are an important part of the coast as they are land's first defence against the forces of the ocean. Because of this, management of sand dunes will focus on the natural authenticity and values of the dunes themselves including flora, fauna, and the ecosystem as a whole. The concept of integrated management can be incorporated into ...
A satellite image of the Sahara, the world's largest hot desert and third largest desert after Antarctica and the Arctic. Desert greening is the process of afforestation or revegetation of deserts for ecological restoration (biodiversity), sustainable farming and forestry, but also for reclamation of natural water systems and other ecological systems that support life.
A well-researched example is the finding that dairy farming created the selection pressure that led to the spread of alleles for adult lactase persistence. [30] Analyses of the human genome have identified many hundreds of genes subject to recent selection, and human cultural activities are thought to be a major source of selection in many cases.
A large dune complex is called a dune field, [7] while broad, flat regions covered with wind-swept sand or dunes, with little or no vegetation, are called ergs or sand seas. [ 8 ] [ 9 ] [ 10 ] Dunes occur in different shapes and sizes, but most kinds of dunes are longer on the stoss (upflow) side, where the sand is pushed up the dune, and have ...
[73] [72] Natural capital is a way of describing environmental resources. People may refer to it as nature. An example for this is the use of environmental technologies to reduce pollution. [74] The opposite concept in that model is strong sustainability. This assumes that nature provides functions that technology cannot replace. [75]
The term nature-based solutions was put forward by practitioners in the late 2000s. At that time it was used by international organisations such as the International Union for Conservation of Nature and the World Bank in the context of finding new solutions to mitigate and adapt to climate change effects by working with natural ecosystems rather than relying purely on engineering interventions.