Marsh or Swamp

[seasong]

The following discusses the common definitions and classifications in English. I can't speak to the definitions used formally by wetland experts... and similarly, specialized lingo has little to do with how they are defined in common usage.

Marshes are classified into salt marshes and freshwater marshes. They are usually defined as low-lying flatland, covered in grassy vegetation, which is submerged at least part of the year. Since most marshes are coastal (the conditions that tend to form them are primarily coastal), they tend to also be saltwater and tide-based. However, they can also form near large lakes, and under unusual conditions (the San Joaquin Freshwater Marsh formed in a dead river channel).

Swamps are usually defined as seasonally flooded lowlands, and generally have more woody plants than marshes and better drainage than bogs*. Because a lowland near the sea usually gets eroded or turns into a bay, and because woody plants typically can not survive in saltwater, they are almost always freshwater. However, there are exceptions again, primarily in the form of mangrove swamps (also called tropical mangrove "forests"), as the mangrove is uniquely suited to living in saltwater... and retaining soil where it might otherwise erode away.

* Bogs are swamps that don't flow. They tend to be waterlogged earth rather than water covered earth, and much, much more treacherous. Most have a layer of decaying vegetation which gradually turns into peat, and a very strong smell.

 

[Desdichado]

Seasong is right -- in common parlance, swamp and marsh, if differentiated at all, are done so by vegetation, not salinity.

Even that is a bit iffy -- it's interesting that the etymology of the word for marsh shows that it is a cognate for the word that means sea in most other Indo-European language. If, in specialist wetlands expert usage, a marsh is now the freshwater version of wetlands, then that is very ironic.

Me? I prefer the word fen.

 

[diaglo]

...and under unusual conditions (the San Joaquin Freshwater Marsh formed in a dead river channel).

this would technically be considered a bayou b/c of its association with a river.

Swamps are usually defined as seasonally flooded lowlands, and generally have more woody plants than marshes and better drainage than bogs*. Because a lowland near the sea usually gets eroded or turns into a bay, and because woody plants typically can not survive in saltwater, they are almost always freshwater. However, there are exceptions again, primarily in the form of mangrove swamps (also called tropical mangrove "forests"), as the mangrove is uniquely suited to living in saltwater... and retaining soil where it might otherwise erode away.

technically mangroves are in marshes. they are called swamp by laypeople. and a swamp that becomes a bay and thus allows salt. has evolved into a marshland. the Chesapeake Bay.

* Bogs are swamps that don't flow. They tend to be waterlogged earth rather than water covered earth, and much, much more treacherous. Most have a layer of decaying vegetation which gradually turns into peat, and a very strong smell.

yes. a bog is a swamp without flow. flow is required for swamps normally. bogs tend to be smaller. mostly b/c a large area covered with water will tend to find somewhere to flow.

 

[diaglo]

Seasong is right -- in common parlance, swamp and marsh, if differentiated at all, are done so by vegetation, not salinity.

those same people would call a pepper or a tomato a vegetable. when clearly it is a fruit.

 

[Mark]

Thanks! I'm looking forward to all the specifics being shared. Great stuff to keep in mind while World Building.

 

[seasong]

this would technically be considered a bayou b/c of its association with a river.

Heh... don't tell that to anyone who lives in Louisiana. A bayou requires a living river, not just a river bed. Bayous ARE a type of lowland waterlogged land, but they are offshoots of a river or lake. They also tend to not have seasonal flooding.

technically mangroves are in marshes. they are called swamp by laypeople. and a swamp that becomes a bay and thus allows salt. has evolved into a marshland. the Chesapeake Bay.

As I stated in my post's introduction, my statements have nothing to do with specialized terminology - they are common usage only. I posted them because someone wanted to know how they should read a book written by a non-wetlands specialist. I can almost (almost) guarantee that the book was not written with any specialist's terminology in mind .

I would also point out that the specialist terms are modern, and changed from the original meanings. They are based on specialists who wanted a definitive, boolean method for saying "this is scientifically a marsh" or "this is scientifically NOT a marsh". Water salinity makes a good test, from that perspective.

But for someone just aiming their eye over the landscape and calling it something, particularly in a fantasy game, "technically brackish, although below 33 parts salt" doesn't work. Historically, both terms have followed the common usage I gave .

 

[seasong]

I don't know how useful this is to the discussion itself, but I felt some inspiration. These are COMMON USAGE definitions, and they're pretty short, but they should give some feel for what each is. Some of these I'm not positive about - particularly fen and slough (I've heard slough used to mean a few things), and I think sump may have had a different meaning prior to about the 1700s and the gold rush mining.

Also, a necessary caveat: I'm not an expert on any of this. I ran a campaign in a wetland bowl years ago, and did some home research (it ended up being a river-fed series of bayous, with some swampland and a series of swales known as "traitor annies" for their tendency to change shape every few years during the flooding).

Swamp (lowlands, seasonal flooding, woody)
Marsh (flatlands, usually tidal, grassland)
Bog (swamp with no flow/flooding, peat layer)
Fen (??? I think it means the same as glade?)
Bayou (lowlands, waterlogged creek, offshoot of lake/river)
Moor (lowlands, year-round water cover, woody)
Glade/Everglade (flatlands, flow, mixed wood/grassland)
Mire (a small, particularly dangerous bog)
Quag (1. marsh with no flow)
Quag (2. a bog)
Quagmire (a small, particularly dangerous quag)
Slough (1. a particularly deep mire; a VERY deep, VERY dangerous bog)
Slough (2. a creek running through a marsh or tide flat)
Sump (the waterlogged section at the bottom of a deep hole; a miner's term)
Bottomland (1. a boggy valley or area between hills)
Bottomland (2. the land bordering a low-lying watercourse)
Swale/Swallow (long, narrow patch of lowland that waterlogs only occasionally)
Sopland (a swamp with little flow; not quite a bog)
Cesspool (a non-flowing body of water; bogs are rife with them)

 

[diaglo]

Heh... don't tell that to anyone who lives in Louisiana. A bayou requires a living river, not just a river bed. Bayous ARE a type of lowland waterlogged land, but they are offshoots of a river or lake. They also tend to not have seasonal flooding.

that's what the wink was for. i was wondering if we'd hear from anyone down LA (state not city) way.

 

[seasong]

Originally posted by seasong
Heh... don't tell that to anyone who lives in Louisiana. A bayou requires a living river, not just a river bed. Bayous ARE a type of lowland waterlogged land, but they are offshoots of a river or lake. They also tend to not have seasonal flooding.

Originally posted by diaglo that's what the wink was for. i was wondering if we'd hear from anyone down LA (state not city) way.