Wetland communities depend on access to liquid water. Throughout geologic history, water availability has varied according to prevailing local and global climate patterns, latitude, elevation, season, and distance from both water bodies and groundwater. As a result of this variability, wetland communities in different parts of the world are the product of different conditions. Hong Kong Wetlands Conservation Association (HKWCA) welcomes and supports the proactive approach on wetland conservation proposed under the Policy Address 2021. Mai Po & Wetlands. © WWF-Hong Kong. The wetlands scattered along the coasts of East and Southeast Asia represent stop-over and wintering habitats for tens of millions of waterbirds—represented by hundreds of species—to rest, feed and replenish energy reserves while undertaking the arduous journey of over 13,000 km, from breeding grounds as ... www.wwf.org.hk › en › wetlandsMai Po Nature Reserve | WWF Hong Kong 在「britannica.com」查看更多資訊 In some of the coldest parts of the world, wetlands are sustained by an impermeable layer of ice that remains in the soil throughout the year. This perennially frozen ground, or permafrost, prevents both the percolation of surface water into the ground and plant contact with mineral groundwater. About 20–22 percent of Earth’s land surface is close enough to a polar region or high enough in altitude to experience permafrost. Much of northern North America and Eurasia, as well as the Mongolian and Tibetan Plateaus, are affected by permafrost, and these regions host vast expanses of bogs, fens, and peatlands. North America possesses some of the most extensive bog and fen regions on Earth. In western Siberia, larch-spruce-birch forests form part of an enormous inland delta, which is the largest contiguous area of peatlands in the world. Asian plateaus in general host some of the most unusual high-altitude wetland ecosystems. Students save 67%! Learn more about our special academic rate today. This definition is also broad enough to encompass open water used by birds—the concept that originally inspired the protection of wetlands and associated aquatic sites. 難以啟齒的話題🔍 www.wetlandpark.gov.hk › enHong Kong Wetland Park www.wwf.org.hk › en › wetlandsMai Po & Wetlands | WWF Hong Kong Located on the northwestern corner of Hong Kong, the Mai Po and Inner Deep Bay wetlands are recognised as a Wetland of International Importance under the prestigious Ramsar Convention. For more than three decades, Mai Po Nature Reserve has been a paradise for birds and a beautiful, irreplaceable piece of China’s wetland kaleidoscope. Wetlands and the subdiscipline of wetland ecology are a relatively new area of study in the field of ecology, primarily arising out of the laws and other regulations enacted during the 1970s. The term wetland, however, was first used formally in 1953, in a report by the U.S. Fish and Wildlife Service (USFWS) that provided a framework for a later publication concerning waterfowl habitat in the United States. Since then, wetlands have been variously defined by ecologists and government officials. No single, formal definition exists; however, the definition provided by the Ramsar Convention, an intergovernmental treaty signed in Ramsar, Iran, in 1971 to guide national and international wetland-conservation measures, is among the most widely referenced: wetland, complex ecosystem characterized by flooding or saturation of the soil, which creates low-oxygen environments that favour a specialized assemblage of plants, animals, and microbes, which exhibit adaptations designed to tolerate periods of sluggishly moving or standing water. Wetlands are usually classified according to soil and plant life as bogs, marshes, swamps, and other similar environments. Ecosystems The Hong Kong Wetland Park is a world-class conservation, education and tourism facility. It demonstrates the diversity of the Hong Kong's wetland ecosystem and highlights the need to conserve them. 相關搜尋 www.britannica.com › science › wetlandWetland | Definition, Characteristics, Animals, Plants, ... 註： 個別活動需提前報名。本日誌的活動，均以本園當日公佈為準；如有更改，恕不另行通知。 特別通告（2024年5月更新） 香港濕地公園展覽及訪客設施提升 香港濕地公園已分階段暫停開放訪客中心內的展覽及訪客設施，以進行設施提升。 圖片 Britannica Quiz 熱門搜尋 www.wetlandpark.gov.hk › tc香港濕地公園 Glaciation during the Pleistocene Epoch (2.6 million to 11,700 years ago) prepared several types of landscapes for the development of present-day wetlands. In glaciated regions, the movement of ice sheets scoured the landscape, and the weight of the ice depressed Earth’s crust below. Both processes created low-relief areas, such as the flat, scoured landscape of Canada’s Hudson Bay lowlands. This region, which hosts extensive wetlands that are fed by groundwater and precipitation, continues to experience isostatic uplift (a rebound in the land that follows a glacier’s retreat) that brings more of Hudson Bay’s bottom to the surface. Some of this new land has become vegetated, and the wetlands have expanded. As the Pleistocene glaciers retreated across the Northern Hemisphere, melt carved wide, flat valleys that are occupied today by major rivers and their associated wetlands and floodplains (flat land area adjacent to a stream). Uneven scouring of the landscape in some regions resulted in low spots that filled with melted snow and rainwater during particularly wet years. This process created the prairie pothole region of the Midwest and south-central Canada. 在「britannica.com」查看更多資訊 hkwca.org.hkHKWCA – Hong Kong Wetlands Conservation Association Wetlands are areas of marsh, fen, peatland or water, whether natural or artificial, permanent or temporary, with water that is static or flowing, fresh, brackish or salt, including areas of marine water the depth of which at low tide does not exceed six metres. Learn More Evidence of the first wetland plants extends back to the Ordovician Period (485.4 million to 443.8 million years ago), when the first terrestrial plants, which were dependent on wet substrates, began to colonize the land. Wetland plants and the animals that depended on them continued to evolve, and the first marshes and swamps appeared during the Devonian Period (419.2 million to 358.9 million years ago). Swamps later dominated vast regions, such as the land that would become southern North America, during the Carboniferous Period (358.9 million to 298.9 million years ago), and parts of the Mesozoic and Cenozoic eras (252.2 million years ago to the present) were also characterized by the presence of extensive wetland habitats. 查看全部