Determining State And Federal Wetland Jurisdiction Determining State and Federal Wetland Jurisdiction – Wetland Plants

WETLAND PLANTS 24th Annual Environmental Permitting Summer School at Marco Island

Presented by Edward Murawski

• Wetland Plant Definition

• Growth Forms

• Representative Plant Groups

• Wetland Plant Morphology and Physiology

• Functions

WETLAND PLANTS DISCUSSION OVERVIEW

Wetland plants are those species that normally grow within areas of standing water or where the soils are saturated within the root zone long enough for anaerobic soil conditions to develop. Wetland plants have morphological and physiological characteristics that enable them to grow in these areas.

Wetland Plant Definition

Wetland plants are often referred to as Hydrophytes

``

4. Floating

Growth Forms

3. Submerged

2. Floating-leaved

1. Emergent

Four Main Growth Forms

Phelps, 1995

Growth Forms – Emergent

Emergent plants are those species rooted in saturated soils or below standing water but have their stems, leaves and reproductive parts above the water level.

``

2. Floating-leaved

Growth Forms

Phelps, 1995

Growth Forms – Floating-leaved

Floating-leaved plants are species that root in the soil and have leaves that float on the surface of the water.

``

Growth Forms

3. Submerged

Phelps, 1995

Growth Forms – Submerged

Submerged plants are rooted in the soils and have their stems and leaves under water. Flowers and other reproductive parts are found both above and below the water column.

Growth Forms - Floating

Floating plants are species that do not root in the soil. These species float on the water column.

Bryophytes – Mosses

Wetland plants are represented by all major plant groups.

Pteridophytes – Ferns and Allies

Gymnosperms – Cypress and Conifers

Angiosperms – Flowering plants

Representative Plant Groups

Bryophytes – Mosses

Herbaceous Species


sphagnum moss (Sphagnum spp.)

Pteridophytes – Ferns and Allies

Herbaceous species

netted chain fern (Woodwardia areolata)

Virginia chain fern (Woodwardia virginiana),

royal fern (Osmunda regalis) and

cinnamon fern (Osumunda cinnamomea)


Gymnosperms – Cypress and Conifers Woody Trees

bald cypress (Taxodium distichum)

pond pine (Pinus serotina)


Angiosperms – Flowering plants

Herbaceous and Woody Species (herbs, shrubs and trees)

duck potato (Sagitaria spp.)

loblolly bay tree (Gordonia lasianthus)

blue flag iris (Iris hexagona)


Wetland Plant Morphology and Physiology

The wetland environment subjects wetland plants to conditions that upland plants do not have the tools to cope with.

The most critical condition is anaerobic soil conditions

(low oxygen levels).

Anaerobic Soil Conditions

Problem – Oxygen deprivation

– When soils are saturated, the air in the void spaces is replaced with water.

– Any oxygen left is used by bacteria and other microorganisms at a rate that exceeds replenishment via diffusion.

– Therefore, saturation results in oxygen deprived soils, which is called anoxia.




– Plants require carbon dioxide for photosynthesis, but plants need oxygen too!

– Just like animal cells, plant cells need oxygen for normal cell functions, including cell division and nutrient absorption.

– These cell functions require energy. Energy is released from biochemical reactions, which is referred to as cellular respiration. Oxygen is required for cellular respiration.




– In the absence of oxygen, plant cells conduct anaerobic respiration.

– Anaerobic respiration is not as efficient as aerobic respiration, but will provide the energy needed until the plant roots are exposed to atmospheric oxygen, either by drainage of water or by development of morphological structures to aid in obtaining oxygen.


Anaerobic Soil Conditions Problem – Oxygen deprivation

Solutions

• Aerenchyma• Specialized root structures• Hypertrophy• Underwater growth techniques• Timing

Plants have several morphological and physiological characteristics that enable the root cells to obtain oxygen for cellular respiration, the release of energy required for cell function. These include:


Oxygen deprivation Solution

Aerenchyma• Aerenchyma are air spaces located

throughout the plant, including the roots. These spaces allow for gas exchange between the aerial parts of the plant and the roots. This provides a connection between the submerged roots and the aerial portion of the plant where oxygen is prevalent.

• Aerenchyma also act as a floatation device to stabilize some species in the water column.


PicsDigger, 2010

Oxygen Deprivation Solution

Specialized Root Structures

Adventious Roots

– Adventious roots are roots that grow from the base of a plants stem above the soil or water surface. These roots grow into the surrounding soil or within the air.

– Adventious roots have the advantage of being exposed to atmospheric oxygen.



Specialized Root Structures

Prop Roots • Prop roots provide stability from wind and tide and aid in oxygen uptake.



Lenticels

Lenticels are small, corky pores or narrow lines on the surface of the stems of woody plants that allow the interchange of gases between the interior tissue and the surrounding air.


Oxygen Deprivation Solution Specialized Root Structures

Pneumatophores• Pneumatophores are roots that grow upward above the soil surface. • Typical Species

- Mangrove species – Aid in uptake of oxygen through lenticels.

- Cypress species – Aid in gas exchange.

Often referred to as “Cypress knees”.

black mangrove (Avicennia germinans) bald cypress (Taxodium distichum)

Oxygen Deprivation Solution Specialized Root Structures Shallow Rooting

• Some species grow their roots close to the surface of the soil.• Shallow rooting enables the roots to maximize their proximity to oxygen

in the atmosphere or water column.

Hypertrophy• Hypertrophy is when the base of the stem of some plant species swell

when subjected to inundation of water. • Formation of aerenchyma is the cause of the swelling. • The swelling assists the plant roots in gaining oxygen as well as with

the stability of the plant in the wetland soils.


OTHER SPECIALIZED STRUCTURES

– Some wetland plant species have large rhizomes.

– Rhizomes are thick fleshy underground stems.

– The rhizomes aid in anaerobic respiration.

– Anaerobic respiration requires larger quantities of glucose than aerobic respiration.

– The rhizomes provide large quantities of carbohydrates to fuel anaerobic respiration until these plants can emerge from the water.

Underwater Growth Techniques• Some species have an ability to grow shoots from below the water

surface very quickly, enabling them to reach the surface of the water.

• This very quick growth rate also aids some deep water species to reach sunlight and oxygen quickly.

• Submerged vegetation tends to be thin or dissected, which provides greater leaf surface to volume ratio, thus increasing the exposure to both light and oxygenated water.


TimingSome wetland plants focus their growth and reproductive activities during periods of dry conditions.


Water quality treatment

Nutrient assimilation

Functions

What do wetland plants do?

Erosion control

Functions

What do wetland plants do?

Support to wildlife

– Cover

– Food

– Nesting and denning sites

FunctionsWhat do wetland plants do?

Wetland plants are those species which normally grow within areas that have standing water or where the soils are saturated within the root zone long enough for anaerobic soils conditions to develop. Wetland plants have morphological and physiological characteristics which enable them to grow in these areas.

Multiple Growth Forms are represented in all the major plant groups.

Wetland Plants provide multiple functions including:

• Water quality treatment• Erosion Control • Wildlife Support

Summary

Presented by Edward Murawski

WETLAND PLANTS

Documents

Determining State And Federal Wetland Jurisdiction Determining State and Federal Wetland Jurisdiction – Wetland Plants