Slide 1: CABIDA, MARVIN V. ASSIGNMENT: 1.Tropical forest Tropical forests are characterized by the greatest diversity of species. They occur near the equator, within the area bounded by latitudes 23.5 degrees N and 23.5 degrees S. One of the major characteristics of tropical forests is their distinct seasonality: winter is absent, and only two seasons are present (rainy and dry). The length of daylight is 12 hours and varies little. 2.Grasslands (also called greenswards) are areas where the vegetation is dominated by grasses (Poaceae) and other herbaceous (non-woody) plants (forbs). Plants of the sedge (Cyperacae) and rush (Juncaceae) families can also be frequent in grasslands. Grasslands occur naturally on all continents except Antarctica, and in many other areas they have replaced the natural vegetation due to human influence. In temperate latitudes, such as north-west Europe, grasslands are dominated by perennial species, whereas in warmer climates annual species form a greater component of the vegetation.[1] Grasslands can be found in most terrestrial climates. Grassland vegetation can vary in height from very short, as in chalk downland where the vegetation may be less than 30 cm high, to quite tall, as in the case of North American tallgrass prairie, South American grasslands and African savanna. Woody plants, shrubs or trees, may occur on some grasslands - forming savannas, scrubby grassland or semi-wooded grassland, such as the African savannas or the Iberian dehesa. Such grasslands are sometimes referred to as woodpasture or woodland. Grasslands cover nearly fifty percent of the land surface of the continent of Africa.[2] While grasslands in general support diverse wildlife, given the lack of hiding places for predators, the African Savanna regions support a much greater diversity in wildlife than do temperate grasslands.[3] The appearance of mountains in the western United States during the Miocene and Pliocene epochs, a period of some 25 million years, created a continental climate favorable to the evolution of grasslands. Existing forest biomes declined, and grasslands became much more widespread. Following the Pleistocene Ice Ages, grasslands expanded in range in the hotter, drier climates, and began to become the dominant land feature worldwide.[4] A restored grassland ecosystem at Morton Arboretum in Illinois. As flowering plants, grasses grow in great concentrations in climates where annual rainfall ranges between 500 mm and 900 mm (approximately 20 to 35 inches).[5] The root systems of perennial grasses and forbs form complex mats that hold the soil in place. Mites, insect larvae, nematodes and earthworms inhabit deep soil, which can reach 6 meters (about 20 feet) underground in undisturbed grasslands on the richest soils of the world. These invertebrates, along with symbiotic fungi, extend the root systems, break apart hard soil, enrich it with urea and other natural fertilizers, trap minerals and water and promote growth (Chadwick 1995). Some types of fungi make the plants more resistant to insect and microbial attacks 3.Freshwater is water containing low concentrations of dissolved salts and other total dissolved solids. A term that refers to bodies of water such as ponds, lakes, rivers and streams containing low concentrations of dissolved salts and other total dissolved solids. Freshwater is an important renewable resource, necessary for the survival of most terrestrial organisms, and is required by humans for drinking and agriculture, among many other uses. The UN estimates that about 1.2 billion people (18 percent of the world's population) lack access to safe drinking water. 4.Mangroves (generally) are trees and shrubs that grow in saline coastal habitats in the tropics and subtropics. The word is used in at least three senses: (1) most broadly to refer to the habitat and entire plant assemblage or mangal [1], for which the terms mangrove swamp and mangrove forest are also used, (2) to refer to all trees and large shrubs in the mangal, and (3) narrowly to refer to the mangrove family of plants, the Rhizophoraceae, or even more specifically just to mangrove trees of the genus Rhizophora. Mangals are found in depositional coastal environments where fine sediments, often with high organic content, collect in areas protected from high energy wave action. 5.Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine geology. As a noun it can be a term for a certain kind of navy, or those enlisted in such a navy. In scientific contexts, the term almost always refers exclusively to saltwater environments, although in other contexts (e.g., engineering) it may refer to any (usually navigable) body of water. 6.An estuary is a semi-enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea.[1] Estuaries are often associated with high rates of biological productivity. An estuary is typically the tidal mouth of a river (aestus is Latin for tide), and estuaries are often characterized by sedimentation or silt carried in from terrestrial runoff and, frequently, from offshore. They are made up of brackish water. Estuaries are more likely to occur on submerged coasts, where the sea level has risen in relation to the land; this process floods valleys to form rias and fjords. These can become estuaries if there is a stream or river flowing into them. Large estuaries, like Chesapeake Bay and Puget Sound, often have many streams flowing into them and can have complex shapes. Estuaries are often given names like bay, sound, fjord, etc. The terms are not mutually exclusive. Where an enormous volume of river water enters the sea (as, for example, from the
Slide 2: Amazon into the South Atlantic) its estuary could be considered to extend well beyond the coast. Estuarine circulation is common in estuaries; this occurs when fresh or brackish water flows out near the surface, while denser saline water flows inward near the bottom. Anti-estuarine flow is its opposite, in which dense water flows out near the bottom and less dense water circulates inward at the surface. These two terms, however, have a broader oceanographic application that extends beyond estuaries proper, such as in describing the circulation of nearly-closed ocean basins. Estuaries are marine environments, whose pH, salinity, and water level are varying, depending on the river that feeds the estuary and the ocean from which it derives its salinity (oceans and seas have different salinity levels). The time it takes an estuary to completely cycle is called flushing time. As ecosystems, the estuaries are under great threat from human activities. They are small, in demand, impacted by events far upstream or out at sea, and concentrate materials such as pollutants and sediments Classes of estuary Salt wedge River output greatly exceeds marine input; there is little mixing, and thus a sharp contrast between fresh surface water and saline bottom water. Highly stratified River output and marine input are more even, with river flow still dominant; turbulence induces more mixing of salt water upward than the reverse. Slightly stratified River output is less than the marine input. Here, turbulence causes mixing of the whole water column, such that salinity varies more longitudinally rather than vertically. Vertically mixed River output is much less than marine input, such that the freshwater contribution is negligible; longitudinal salinity variation only. Inverse estuary Located in regions with high evaporation, there is no freshwater input and in fact salinity increases inland; overall flow is inward at the surface, downwells at the inland terminus, and flows outward subsurface. Intermittent estuary Estuary type varies dramatically depending on freshwater input, and is capable of changing from a wholly marine embayment to any of the other estuary types.[3] Grouped by structure rather than circulation, there are other types of estuaries. Bar-built estuaries are effectively synonymous with barrier island lagoons, such as Texas's Laguna Madre. Tectonic estuaries form when the sea floods a geologically subsident region, coastal plain estuaries are flooded river valleys, and fjords are submerged glacier-eroded valleys. 7. swamp is a wetland that features temporary or permanent inundation of large areas of land by shallow bodies of water, generally with a substantial number of hammocks, or dry-land protrusions, and covered by aquatic vegetation, or vegetation that tolerates periodical inundation.[1] The water of a swamp may be fresh water or salt water. A swamp is also generally defined as having no substantial peat deposits.[2] In North America, swamps are usually regarded as including a large amount of woody vegetation, but elsewhere this may not necessarily apply, such as in African swamps dominated by papyrus. By contrast a marsh in North America is a wetland without woody vegetation, or elsewhere, a wetland without woody vegetation which is shallower and has less open water surface than a swamp. A mire (or quagmire) is a low-lying wetland of deep, soft soil or mud that sinks underfoot. 7.marsh, or morass, is a type of wetland which is subject to frequent or continuous inundation.[1] Typically a marsh features grasses, rushes, reeds, typhas, sedges, and other herbaceous plants (possibly with low-growing woody plants) in a context of shallow water. A marsh is different from a swamp, which has a greater proportion of open water surface, and is generally deeper than a marsh. In North America, the term swamp is used for wetland dominated by trees rather than grasses and low herbs. The water of a marsh can be fresh, brackish or saline. Coastal marshes may be associated with estuaries and along waterways between coastal barrier islands and the inner coast. The estuarine marsh, or tidal marsh, is often based on soils consisting of sandy bottoms or bay muds. An example is the Tantramar Marsh of eastern Canada. Below water decomposition processes often produce marsh gas, which may through self-ignition manifest as Will o' the wisps (aka. Jack-a-lanterns or spirites). Marshes are critically important wildlife habitats, often serving as breeding grounds for a wide variety of animal life. Constructed wetlands featuring surface-flow design are usually in the form of a marsh. 8.A crop is any plant that is grown in significant quantities to be harvested as food, livestock fodder, or for any other economic purpose. This category includes crop species as well as agricultural techniques related to cropping. There are many types of crops that are used for industrial purposes. For example, cash crops, are grown and harvested for the sole purpose of making profit, as they are grown in large amounts in a certain area fitted for growing crops.