50+ Wetlands Features For Fantasy Worldbuilding30 min read

Bog and fen and marsh and swamp, oh my! Welcome back, Outlander, to the 2nd entry in Mythic Ecology, my series on how learning real-world landscape features can enrich our fantasy worldbuilding and storytelling. In this post I return to my minimalist framework for Dungeon Masters, Game Masters, fiction writers, and similar worldbuilders to merge the realms of general myth and geomorphology. Last week we looked at coasts. As I resume my journey sketching a framework for designing Yridia, my unique D&D 5e fantasy world, let’s learn some wetlands terms and processes, with a visual guide!

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Let’s revisit my minimalist framework for my worldbuilding, which will unfold gradually. The six archetype tags with which I will flag all the various real-world land features in my Mythic Ecology Series:

1. Settlements: habitable regions of either Work or Play, Familiar or Exotic, offering diverse narrative functions: a Day in the Life, Home Base, Personal Reasons, Gathering Supplies. Can subvert tropes with Ruins or Escape.
2. Omens: sensational, temporal, or particularly pointed features that offer narrative functions of forshadowing, and good or evil portents. Can subvert tropes with a Wild Goose Chase.
3. Overlooks: sites of magnitude and grandeur, living monuments which can function narratively for finding resolve, invoking spirits, or as a Call to Adventure. Can subvert tropes with Dread or Betrayal.
4. Passageways: transitional journeylands, including magical portals, functioning narratively for initiation and return, thresholds and tests, shortcuts and setbacks.
5. Abyss: a void or confined space presenting scarcity or temptation, desperation and danger. Can subvert tropes with a Timely Rescue or Secret Refuge.
6. Battlegrounds: sites fit for epic, sprawling encounters and climax conflicts. Can subvert tropes with Alternative Solutions.

Feel free to submit your own ideas, or draw outside the lines. Alright, let’s see how wetlands fit into this.

4 MAJOR TYPES: BOG, FEN, MARSH, SWAMP

Wetlands can form from exposure to open ocean, tidal river mouths, rivers and streams, lakes and reservoirs, and rainfall. They come in four major categories: bog, fen, marsh, and swamp. Bogs and fen comprise mires: both have short or submerged vegetation, but bogs have high acidity (from rainfall) and fen have neutral to alkaline character (from lakes or streams). Marshes, neutral to alkaline, can have saltwater, brackish, or freshwater, and have taller herbaceous plants. Finally, swamps have full shrubs and trees.

If you want to keep it simple you can stick to just this basic system of four types, and imagine the varying atmospheres they evoke. We can go deeper even with that, by adding dimensions of time, movement, and mood.

6 ECOLOGICAL PROCESSES, 6 BASIC EMOTIONS

Now, six main ecological processes dictate wetland development, explained below. And since this series covers not just ecology, but Mythic Ecology for storytelling, I’ve mapped these processes onto “sample story moods” you can choose to evoke for atmosphere and extend into themes, drawing a bit upon the Theory of Six Basic Emotions.
1. Eutrophication: influxes of certain minerals and nutrients can cause enrichment blooms but reduce biodiversity. Sample Story Mood: Mania.
2. Acidification: influxes of rain can increase acidity, threatening non-adapted species. Sample Story Mood: Disgust.
3. Salinization: influxes of saltwater from oceans increase saltiness, threatening non-adapted species. Sample Story Mood: Bitterness.
4. Sedimentation: influxes of sediment deposited by currents can smother existing lifeforms, bring pioneers or invasives, change stability. Sample Story Mood: Anger.
5. Aridification: exodus of moisture causing soil exposure or degradation, via climate change, reduced precipitation, increased evaporation, lowering of water tables, or groundcover changes. Sample Story Mood: Fear.
6. Inundation: influx of moisture via flooding, which quenches or drowns existing lifeforms. Sample Story Mood: Surprise.

How do these ecological processes shape wetlands? Let’s take a look.

As I covered Coasts in my previous entry, let’s start with a transitional progression from sea to wetland. Maritime habitats progress from Rock Bottom to Unconsolidated Bottom to Aquatic Bed to Reef to Streambed, before we finally reach the following zones:

1. Rocky Shore – wetlands dominated by bedrock, boulders, and stones, with the vegetation as primarily pioneer plants. Water level range if tidal spans irregularly exposed to irregularly flooded, and if non-tidal spans seasonally to intermittently flooded.

2. Unconsolidated Shore – wetlands dominated by loose materials like cobble, gravel, sand, mud, organic soils, and dead weeds, with the vegetation as primarily pioneer plants. Can include beaches, bars, flats, salt flats, pans, salt pans, inland saline flats, alkali flats. Water level range if tidal spans irregularly exposed to irregularly flooded, and if non-tidal spans seasonally to intermittently or artificially flooded.

3. Moss-Lichen Wetlands – wetlands dominated by moss and lichens in saturated waters, with few trees, shrubs, and emergent waterplants. Can include bog, fen. Water level range includes only non-tidal: saturated.

4. Emergent Wetlands – wetlands dominated by standing, rooted, herbaceous waterplants, usually perennials, excluding mosses and lichens. Can include marsh, meadow, fen, praerie pothole, and slough. Water level range if tidal spans regularly to irregularly flooded, and if non-tidal spans permanently to intermittently flooded.

5. Scrub-Shrub Wetlands – wetlands dominated by woody vegetation like shrubs and young trees, particularly small or stunted ones. Can include shrub swamp, shrub carr, bog, pocosin. Water level range if tidal spans irregularly exposed to irregularly flooded, and if non-tidal spans permanently to intermittently flooded.

6. Forested Wetlands – wetlands dominated by an overstory of tall woody vegetation, with an understory of young trees or shrubs and a herbaceous layer. Can include mangroves, swamps, hammocks, heads, and bottoms. Water level range if tidal spans irregularly exposed to irregularly flooded, and if non-tidal spans permanently to intermittently flooded. Categories include broad-leaved deciduous, needle-leaved deciduous, broad-leaved evergreen, needle-leaved evergreen, dead.

Let’s unpack the details on all these. I’ll cover different types of bogs & fen, raised bogs, marshes & mudflats, swamps, and wetland depressions, adding my story archetype tags for each element.

Mire / Quagmire – any wetland dominated by living, peat-forming plants (i.e. all bogs and fens, some marshes and swamps); AKA “peatland”.
[Passageways]

Bog – a mossy, nutrient-poor acidic wetland unconnected to lakes or streams. Lots of reptiles and bugs and bug-eating plants and sphagnum, sometimes orchids, but few fish. Consists of an acrotelm, the highly permeable upper layer of decomposing peat and living plants, and the catotelm, the minimally permeable lower layer of dense peat and dead plant material. Water comes from the atmosphere.
[Settlements, Omens, Overlooks, Passageways, Abyss, Battlegrounds]

Fen – a lush, alkaline wetland connected to small lakes or streams. Can have grasses, sedges, meadows. Water comes from groundwater seepage. Calcium-rich fens develop flowers like orchids.
[Settlements, Omens, Overlooks, Passageways, Battlegrounds]

Cataract Bog – a rare habitat where permanent stream flows over a granite outcrop, and water sheeting wets the rocks but does not erode the soil, causing a narrow, wet, but sunny habitat devoid of trees and large shrubs. Often partly shaded by nearby vegetation, and develops an algae film. Technically a fen, but with bog plants.
[Omens, Passageways]

Dambo – fen with grasses, rushes and sedges, contrasting with surrounding woodland. Often substantially dry at end of dry season revealing grey soils or black clays. Unlike a flooded grassland, retains wet lines of drainage through dry season. Waterlogged in wet season but not above vegetation, with surface water confined to streams, rivers, and small ponds or lagoons at a low point (usually center).
[Settlements, Omens, Passageways, Battlegrounds]

Missen – small, shallow pine forest bogs forming on hills or mountains with high precipitation and low drainage, with a thin layer of peat and poor tree growth.
[Passageways, Abyss]

Moorland / Moor – upland areas in temperate grasslands, savannas, and shrublands, montane grasslands and shrublands biomes with low-growing vegetation on acidic soils, uncultivated hills and low-lying wetlands. Appears where tundra retreat.
[Overlooks, Passageways, Battlegrounds]

Muskeg – boreal and arctic wetlands with features ranging from sphagnum moss, to sedge peat, to decomposed humus, and some wood matter.
[Settlements, Omens, Passageways, Battlegrounds]

Pocosin – evergreen shrub bogs, a palustrine wetland with deep, acidic, sandy, peat soils. Poorly drained higher ground between streams and floodplains. Seeps cause inundation. Has fire-adapted pines.
[Passageways, Abyss]

Poor Fen / Transitional Bog / Transitional Mire / Sedge Mire – wetland with a dense carpet of mosses and sedges, intermediate between the taller vegetation of the less acidic fen and and short, mossy vegetation of a more acidic bog.
[Omens, Passageways, Abyss]

Quaking Bog – forms in wetter parts of valley or raised bogs and sometimes acidic lake edges. Sphagnum moss and sedges combine to form a floating mat, which can shake underfoot and sometimes detaches and becomes a floating island.
[Omens, Passageways, Abyss]

Valley Bog – bogs in gently sloping valleys or hollows with a layer of peat filling the deepest recesses. Can develop in relatively dry and warm climates from acidic surface-water.
[Settlements, Passageways, Abyss, Battlegrounds]

Blanket Bog / Blanket Mire / Featherbed Bog – peatland forming under high rainfall covering both wet hollows and undulating expanses.
[Settlements, Passageways, Battlegrounds]

Mountain / Upland Bogs – bogs forming at montane or alpine levels, with sloping and asymmetric or non-concentric terrain. Includes plateau bogs, hillside bogs on mountain passes, saddle bogs, summit & crest bogs.
[Settlements, Overlooks, Passageways, Battlegrounds]

Palsa Bogs / Palsamoore – bogs found on tundra margins, characterized by tall concentric ridges, gradual ice lenses, and limited peat formation.
[Omens, Overlooks, Passageways]

Plateau Bogs – bogs with a lens shape, growing more at the center rather than margin, which forms a flat, treeless bulge, with shallow wet depressions (flarks) alternating with hummocks of drier peat moss. Large cores become kolks or bog ponds. Includes kermi bogs, which have a slightly domed shape, broad lagg, a large kolk, and ridge-shaped hummocks of peat moss aligned with the bog’s contours.
[Settlements, Passageways, Battlegrounds]

Polygonal Bogs – bogs with minimal peat, featuring honeycomb-shaped interiors and polygonal margins which capture summer meltwater. Associated with patterned peatland and ice wedges.
[Omens, Passageways]

String Bogs / Strong Mire / Aapa Fens – islands within wetlands which manifest irregularly on ground level islands or forming ridges parallel to hillside contours, separating boggy hollows. Associated with seasonal freezing and thawing, which supplies mineral soil water.
[Omens, Passageways]

Marsh – inundated herbaceous wetland of rushes and sedges, found along rivers, coasts, and estuaries which flood and drain by adjacent estuary, sea, or ocean. Includes tidal and non-tidal types. Brackish marshes may develop alongside salt marshes where freshwater influxes dilute seawater. Salt and brackish marshes develop salt pannes and pools.
[Settlements, Omens, Overlooks, Passageways, Abyss, Battlegrounds]

Mudflats / Tidal Flats – low-lying areas of marshes, covered with large, flat expanses of mud like fine silts and clay, as well as marine animal detritus. They form as tides or rivers deposit mud. Key habitat for migratory shorebirds.
[Settlements, Passageways, Abyss, Battlegrounds]

Backswamp – depositional environment, usually in a floodplain, where fine silts and clays settle after a flood. Usually found behind a stream’s natural levees, at lowest point in a river valley.
[Settlements, Passageways, Battlegrounds]

Callows – seasonally-flooded grasslands in low-lying river floodplains.
[Settlements, Omens, Passageways]

Cienega – alkaline, freshwater, spongy wet meadows with shallow-gradient, permanently saturated black or anaerobic soils in otherwise arid landscapes, often filling valley bottoms. Forms from water forced to the surface over large areas, where it slowly percolates along wide mats of thick sod. Associated with seeps, springs, canyon headwaters, stream margins.
[Omens, Passageways]

Freshwater Marsh – non-tidal marshes containing freshwater, usually found near river mouths with low drainage. Unlike mires, they contain little to no peat. Mineralized types arise from groundwater, streams, and runoff, while poorly mineralized types arise from precipitation.
[Settlements, Passageways, Battlegrounds]

Salt Marsh / Tidal Marsh – tidal marshes with brackish or open saltwater, with dense stands of salt-tolerant terrestrial plants holding sediment, delivering nutrients to coastal waters.
[Settlements, Passageways, Battlegrounds]

Wet-Meadow – marshes fluctuating between brief inundation and longer periods of saturation, whereas meadows are dry marshes. May have sedges, rushes, and grasses. Also includes wet prairie and wet savanna.
[Settlements, Omens, Passageways, Battlegrounds]

Swamp – wooded wetland; permanently waterlogged ground, woody shrubs, reeds.
[Settlements, Omens, Overlooks, Passageways, Abyss, Battlegrounds]

Carr – waterlogged wooded terrain representing the succession stage between a reedy swamp and a sub-maritime forest, which progresses into sedge fens and eventually riparian trees and bushes as acidity neutralizes and soil rises.
[Settlements, Omens, Overlooks, Passageways]

Freshwater Swamp Forest / Flooded Forest – forests permanently or seasonally inundated with freshwater, usually occurring near rivers or lakes. This includes two types of relatively open forests with seasonal flooding: igapó with blackwater, and várzea with whitewater.
[Settlements, Omens, Overlooks, Passageways]

Mangrove Swamp / Mangal – coastal habitats featuring mangroves, a shrub or small tree in saline or brackish water, where fine sediment, often high in organic matter, collects in areas protected from strong waves.
[Omens, Overlooks, Passageways]

Peat Swamp Forest – tropical moist forests where waterlogged soil prevents dead leaves and wood from fully decomposing, over time creating a thick layer of acidic peat.
[Settlements, Passageways, Abyss]

Note: several of these, such as potholes and vernal pools, also qualify as marshes. For worldbuilding, for the most part you can sprinkle these details into your larger wetlands ecologies to add character and interactions.

Carolina Bays / Pock Marks / Bagols / Lacs Ronds – elliptical or oval shaped interior depressions of shallow depth with raised sand rims, contrasting interior and exterior soils. Flat sandy bottoms beneath interior fill, and a northwest-southeast orientation and parallel axes. May also include Grady Ponds / Citronelle Ponds – forested, seasonally-flooded depressions on flat, uneroded surfaces along coasts.
[Settlements, Omens, Passageways]

Interdunal Wetland / Interdunal Pond / Dune Slack – shallow, water-filled depression between coastal sand dunes, formed by either wind erosion or dunal encroachment.
[Omens, Overlooks, Passageways, Battlegrounds]

Lagg / Moat – very wet zone on a peatland’s or bog’s perimeter, where water from adjacent upland collects and flows slowly around the main peat mass. Often contains shrubs and murky water. Laggs also pick up water flowing down from a raised bog’s domed center via small water channels to the steeply sloping shoulder (rand) of the bog.
[Settlements, Omens, Abyss]

Pothole / Kettle / Swirlhole / Hollow/ Rock Mill / Churn Hole / Eddy Mill / Kolk – a smooth, bowl-shaped or cylindrical hollow, deeper than wide, carved into the rocky bed of a watercourse. These arise from the grinding action of stones and coarse sediment whirling from eddies and streamflow. Can become kettle bogs or kettle peatlands (mire).
[Omens, Passageways, Abyss]

Ridge & Swale / Dune & Swale – an alternating pattern of narrow sandy ridges and saturated depressions (swales) parallel to a lakeshore. These formed when glaciers retreated and left mounds of sand and sediment as dunes or ridges. Prime migratory bird habitat.
[Omens, Overlooks, Passageways, Battlegrounds]

Salt Pannes and Pools – water-retaining depressions located within salt marshes. Pools retain water during summer between high tides, whereas pannes do not. Pannes start when a mat of organic debris (wrack) covers existing vegetation, killing it. Often prime mosquito habitat.
[Omens, Passageways, Abyss]

Slough / Tidal Channel – stagnant or seasonally slow-flowing wetland, usually swamp or shallow lake, often backwater to larger body of water or riverine side-channel, or a sporadically-filled inlet, or former rivermouth cut off from source.
[Settlements, Passageways]

Vernal Pool / Ephemeral Pool – temporary pools of water usually devoid of fish.
[Omens, Passageways, Abyss]

I hope you enjoyed this second entry in my Mythic Ecology series! I look forward to continuing with it, I have some greater ambitions for developing this series into worldbuilding web tools. Give this a share if you liked it, and let me know in the comments if you have any feedback. I publish new posts on Tuesdays. In the meantime, I post original D&D memes and writing updates daily over on my site’s Facebook Page. Also, if you want to keep up-to-date on all my posts, check out my Newsletter Sign-Up to receive email notifications when I release new posts. A big thanks as always to my Patrons on Patreon, helping keep this project going: Anthony, Eric & Jones, Geoff, Jason, and Rudy. Thanks for your support!

Special Thanks & Citation:
Cowardin, L. M., V. Carter, F. C. Golet, E. T. LaRoe. 1979. Classification of wetlands and deepwater habitats of the United States. U.S. Department of the Interior, Fish and Wildlife Service, Washington, D.C. Jamestown, ND: Northern Prairie Wildlife Research Center Online. http://www.npwrc.usgs.gov/resource/wetlands/classwet/index.htm (Version 04DEC1998).

Thanks to u/Cruzzfish1 for a correction on bogs.