Rivers, streams and groundwater systems – replenished by rainfall – produce water that sustains all living things. Pollination allows fruit trees to produce fruit and other agricultural crops to grow. Forests sequester carbon, provide timber for wood products, and serve as home for wildlife. Fisheries are a source of food for humans and other species, and estuaries serve as nurseries for fish, shell fish and other marine life. All living creatures depend on such “ecosystem services” or the regular functioning of natural systems that contribute separate but connected strands in the web of life. Diverse and healthy ecosystems and the services they provide are key to sustaining life on Earth.
Spiral Pine Needle Cookstove
In Uttrakand, India, wood fuel is a scarce commodity, as it is illegal to cut branches from the government-owned pine trees. The...
EcosystemLast Updated on 2014-09-24 22:46:28An ecosystem is a community of organisms interacting with each other and with their environment such that energy is exchanged and system-level processes, such as the cycling of elements, emerge.
The ecosystem is a core concept in Biology and Ecology, serving as the level of biological organization in which organisms interact simultaneously with each other and with their environment. As such, ecosystems are a level above that of the ecological community (organisms of different species interacting with each other) but are at a level below, or equal to, biomes and the biosphere. Essentially, biomes are regional ecosystems, and the biosphere is the largest of all possible ecosystems.
Ecosystems include living organisms, the dead organic matter produced by them, the abiotic environment within which the organisms live and exchange elements (soils, water, atmosphere), and the interactions... More »
PollinationLast Updated on 2014-09-06 22:10:21
Pollination in angiosperms and gymnosperms is the process that transfers pollen grains, which contain the male gametes (sperm) to where the female gamete(s) are contained within the carpel; in gymnosperms the pollen is directly applied to the ovule itself. The receptive part of the carpel is called a stigma in the flowers of angiosperms. The receptive part of the gymnosperm ovule is called the micropyle.
The study of pollination brings together many disciplines, such as botany, horticulture, entomology, and ecology. The pollination process as an interaction between flower and vector was first addressed in the 18th century by Christian Konrad Sprengel.
Pollination is a necessary step in the sexual reproduction of flowering plants, resulting in the production of offspring that are genetically diverse. It is important in horticulture and agriculture, because fruiting is... More »
Challenges of modeling and valuing of ecosystem servicesLast Updated on 2014-07-02 11:36:10The Millennium Ecosystem Assessment (MA) has outlined a clear logic: natural resources provide ecosystem services that contribute to human well-being, from nutrient cycling and carbon sequestration to recreational experiences. These ecosystem services are under constant threat from human activities. Through their actions, humans realise economic gains but also decrease their chances of enjoying sustained well-being for future as well as current generations. Economics can help integrate such losses of ecosystem services into decision making, by clarifying the synergies and trade-offs that come from land and ecosystem management. However, the science of ecosystem services is still in its infancy and methods vary wildly.
One result of the MA process is that the popularity of the ecosystem services concept has taken flight, both in science and policy-making. This is due to its... More »
National Oceanic and Atmospheric Administration (NOAA), United StatesLast Updated on 2014-06-30 19:00:15
The National Oceanic and Atmospheric Administration (NOAA) is a federal agency within the United States Department of Commerce. As a science-based operational agency tasked with monitoring climate and changes in the environment, NOAA is responsible for the study of the atmosphere and the oceans. The agency issues daily weather forecasts and storm warnings, restores coastline, aids the flow of marine commerce, and manages fisheries. NOAA's activities facilitate weather- and climate-sensitive economic activity that account for roughly one-third of the country's gross domestic product (GDP). The agency also responds to natural and man-made maritime disasters, operates a complex network of oceanographic, meteorological and atmospheric data-collecting products and services, and manages marine mammals, marine endangered... More »
Ecosystems and Human Well-Being: Volume 1: Current State and Trends: Urban SystemsLast Updated on 2014-06-28 17:05:25This is Chapter 27 of the Millenium Ecosystem Assessment report Ecosystems and Human Well-Being: Volume 1: Current State and Trends
Coordinating Lead Authors: Gordon McGranahan, Peter Marcotullio
Lead Authors: Xuemei Bai, Deborah Balk, Tania Braga, Ian Douglas, Thomas Elmqvist, William Rees, David Satterthwaite, Jacob Songsore, Hania Zlotnik
Review Editors: Jerry Eades, Exequiel Ezcurra
Urbanization and urban growth continue to be major demographic trends. The world’s urban population increased from about 200 million (~15% of world population) in 1900 to 2.9 billion (~50% of world population) in 2000, and the number of cities with populations in excess of 1 million increased from 17 in 1900 to 388 in 2000. As people are increasingly living in cities, and as cities act as both human ecosystem habitats and drivers of ecosystem change, it will become increasingly... More »
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