Definition - What does Palustrine Wetland mean?
A palustrine wetland is an inland freshwater area dominated by vegetation. It is non-tidal with ocean derived salinity of less than 0.5%. The word palustrine is derived from ‘palus’ which means marsh in Latin. These wetlands are dominated by trees, shrubs, emergent mosses, lichens, and persistent emergent.
Palustrine wetlands are an important part of an ecosystem and serve as habitats or breeding areas for different species. Some palustrine wetlands may lack their characteristic vegetation but all such wetlands have four defining characteristics:
1. They are spread in an area of 20 acres or less
2. They do not have tidal waves, shoreline, or wave formations
3. The salinity is less than 0.5%
4. The maximum depth is 2 m at the deepest part in low water
Palustrine wetlands are abundant throughout the United States. While laying pipeline, it is not uncommon to encounter one of these sites on the project route. To minimize the impact on these wetlands, trenchless technology uses boring, horizontal drilling, and microtunneling to cross under such areas.
Palustrine wetlands can regenerate very quickly, usually within one growing season, hence, any disturbance to a limited area is easily restored. Trenchless construction allows for the laying of pipelines in such areas without disturbing the delicate balance or causing any damage or disturbance to natural habitats.
These wetlands are also known as marsh, bog, and swamp.
Trenchlesspedia explains Palustrine Wetland
The palustrine wetland system is used to denote vegetated wetlands known traditionally as marsh, bog, fen, prairie, swamp, etc. including ponds. They are situated on river flood plains, isolated catchments, slopes, shoreward of lakes, river channels, or estuaries. Palustrine wetlands can exist next to or within lacustrine, riverine, or estuarine systems or as islands in lakes or rivers.
Preservation of Wetlands
Palustrine wetlands and other such wetland systems are a rich habitat of a variety of flora, fauna, and aquatic species. These wetlands act as water filters, prevent erosion and act as flood controls. They are also a rich source of food for fish and wildlife. Construction activities near these environmentally sensitive locations can prove harmful for these delicate life forms. Waste products from construction processes are also sometimes dumped near these water bodies which can be very harmful to the environment. It is necessary to conserve these locations to preserve the delicate balance of the ecosystem that exists in such areas.
Types of Wetlands
The National Oceanic and Atmospheric Administration (NOAA) classifies wetlands into five general types: estuarine (estuary), riverine (river), lacustrine (lake), and palustrine (marsh). Wetlands are also known by other names such as mangroves, deltas, coral reefs, floodplains, ponds, billabongs, mudflats, etc. They vary widely due to differences in soil, climate, vegetation, topography, and water chemistry.
Wetlands do not necessarily remain wet throughout the year as seasonal changes can cause water levels to change such as low water levels during the high summer season. However, during periods of excessive rain, these wetlands absorb and slow floodwaters, preventing damage to property and life. Another important function of wetlands is that they absorb excess nutrients, sediments, and pollutants before they reach other water bodies.
Environmentally Sensitive Trenchless Methods
Trenchless methods are known as such because they do not require trenches to be dug to install pipelines or other utility structures. It is carried out at a suitable depth below the earth’s surface eliminating the risk of harming any environmentally sensitive water bodies above the surface. Horizontal directional drilling (HDD), microtunneling, and pipe jacking are some of the widely used trenchless methods to cross under environmentally sensitive locations.