Classifying Wetlands Part 2

Last week’s Wetland Wednesday mentioned 3 main criteria as part of identifying a wetland (wetland hydrology, hydrophytic vegetation, and hydric soils). – Today we’ll look at how plants and soils help scientists delineate wetlands.

In the field, scientists identify and sample soils and plants as part of wetland delineation. The LSU AgCenter groups plant species based on where the plant is naturally found as seen in the table below.

indicator_2Wetland plants have adapted to flooded soils. “Obligate” plants can tolerate water at high levels or when soil saturation is a normal condition to that area. Examples of these plants include the bald cypress (Taxodium distichum), or cattail (Typha latifolia) [3].

In contrast, plants that cannot handle flooded conditions for an extended period would naturally be in the “upland” area of land (i.e. winged sumac (Rhus copallina), eastern redbud (Cercis canadensis), or panic grass (Dichanthelium sp.) [3].

People delineating wetlands focus on a project area according to aerial and soil maps along with aerial photographs [1]. Delineators then take soil samples and determine characteristics seen in hydric soils which relate to cycles of flooding and drying. – Examples of those include oxidized soils, hydrogen sulfide (rotten egg smell) and organic bodies found on plant roots. Finally, the plant and soil types are compared, tested, then matched to determine wetland boundaries for mapping and policy purposes [1].

Wetland delineation is a tool for protecting and documenting these important landscapes which contribute to a healthy and functional environment. It is important to note that wetland delineation requires much more than just plant and soil identification. CWPPRA utilizes sound science, engineering, mapping, and geo-technical surveys in the process of planning, approving, constructing, and maintaining coastal Louisiana wetland restoration projects.

Sources:

[1] Bedhun, Rebecca. 2018. “Watch and Lean Now: How To Do A Wetland Delineation”. Shoret Elliot Hendrickson Inc. Available: http://www.sehinc.com/news/watch-and-learn-now-how-do-wetland-delineation [September 9, 2018]

[2] Jon Kusler. “Common Questions: Wetland Definition, Delineation, and Mapping”. Association of State Wetland Managers, Inc. Available: https://www.aswm.org/pdf_lib/14_mapping_6_26_06.pdf [September 9, 2018]

[3] LSU Ag Center. 2018. Louisiana Plant Identification: Plant List. Available: http://www.rnr.lsu.edu/plantid/listcommon.htm [September 10, 2018]

 

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Classifying Wetlands Part 1

When we think of wetlands, our mind may paint a picture of a swampy area with open water, and maybe a heron or alligator. Despite common perception, not all wetlands are the same. — These watery features come in all shapes, sizes, and locations along with a unique system of processes and purpose.

Wetlands are diverse and the difference between dry and wet environment lies along a gradient. Therfore, there cannot be one perfect definition to represent what a wetland is. Scientists have developed criteria to identify wetlands and aid in assessment, inventory, and management [1].

Figure 1. An example used by scientists to start the process for wetland delineation.

Criteria Definition
Wetland hydrology the gradient or degree of flooding or soil saturation across a landscape [2].
Hydrophytic vegetation plants adapted to grow in water or in a soil that is occasionally oxygen deficient due to saturation by water [2].
Hydric soils soils that are sufficiently wet in the upper root zone  and may develop anaerobic (oxygen lacking) conditions during the length of at least 1-2 growing seasons [2].

As seen below in Figure 2 and 3; some wetlands are flooded year-round while other  water levels fluctuate. The wetland hydrology differs depending on location and the geography of the landscape.

Figure 2: A simplified example of a wetland water gradient dependent on elevation and tidal ranges.

better_gradient pic.png

Figure 3.

basic_gradientYou may not live close to a coastal marsh, but many water sources eventually connect to a wetland on the coast, making the streams, lakes, and swamps in your backyard an important link to the larger watershed. That’s why it’s important to support, respect, and appreciate the water systems and land of everyday life. CWPPRA projects restore and protect these systems to support the livelihood and cultures of Louisiana and to protect the land we value so dearly.

In next week’s edition of Wetland Wednesday, we’ll look at how scientist use vegetation and soils to classify wetlands!

 

Source:
[1] Fish and Wildlife Service. Classification of Wetlands and Deepwater Habitats of the United States. Available: https://www.fws.gov/wetlands/documents/Classification-of-Wetlands-and-Deepwater-Habitats-of-the-United-States-2013.pdf [August 27, 2018].
[2] Natural Resources Conservation Service. Hydric Soils Overview. Available: https://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/use/hydric/?cid=nrcs142p2_053985 [August 27, 2018].

Soil Biology

Soil biology may be considered the most important component of soil health and production [1]. Soil food web’s have tiny, microscopic organisms; also known as microorganisms. These living creatures may be tiny, but they live as very large populations in the soil, and other natural environments like water, air, and plants roots.

Soil_Food_Web

The Four Main Microorganism Groups of Soil:

  1. Soil Bacteria (mostly decomposers) [2].
  2. Soil Fungi
  3. Soil Protozoa (feed mostly on bacteria) [4].
  4. Soil Nematodes (feed on plants, bacteria, fungi, and/or other nematodes) [5].

The other two main groups of Soil Biology:

  1. Soil Arthropods (have no backbone) [6].
  2. Soil Earthworms

Soil Organisms

Microorganisms help bind soil together, which helps clean the soil and hold water for plant life. In ecosystems like wetlands, diverse communities of bacteria can help plants fight off harmful diseases. A major benefit of soil microorganisms is the decomposition of dead plant and animal life, along with the breakdown and creation of nutrients.

Advantages of Soil Organisms: [1, 10].

  • Create healthy nutrients for plants
  • Improve Soil Health and quality (nutrient rich, water holding capacity)
  • Fight off diseases for plants
  • Degrade human-caused pollutants (fertilizers, pesticides used in agriculture)
  • Benefit the food-web as a whole
  • Improve plant health and longevity
  • Microbiomes transform dead plant materials into soil organic matter

The living organisms of the soil provide the requirements needed to support plant, animal, and human life. You can support healthy microorganism communities in soil by: 

  • decreasing or preventing plowing and tilling in garden and agriculture fields [9].
  • plant cover crops to reduce soil erosion and funnel carbon into the atmosphere [9].
  • conserving microbes that provide biomass to plants
  • incorporate soil health management systems into your daily practices [10]
  • protect the soil from weather applying mulch / and or cover crops
  • proper composting

Interesting Facts draft2

Work Cited:
[1] Effective Microorganisms of New Zealand, https://www.emnz.com/article/soil-health-series-soil-microbes
[2] Ingham, Elaine R.  “Soil Bacteria”. USDA, Natural Resources Conservation Service, 26 March 2018, https://www.nrcs.usda.gov/wps/portal/nrcs/detailfull/soils/health/biology/?cid=nrcs142p2_053862
[3] Ingham, Elaine R.  “Food Web & Soil Health”. USDA, Natural Resources Conservation Service, 26 March 2018, https://www.nrcs.usda.gov/wps/portal/nrcs/detailfull/soils/health/biology/?cid=nrcs142p2_053865
[4] Ingham, Elaine R.  “Soil Protozoa”. USDA, Natural Resources Conservation Service, 26 March 2018, https://www.nrcs.usda.gov/wps/portal/nrcs/detailfull/soils/health/biology/?cid=nrcs142p2_053867
[5] Ingham, Elaine R.  “Soil Nematodes”. USDA, Natural Resources Conservation Service, 26 March 2018, https://www.nrcs.usda.gov/wps/portal/nrcs/detailfull/soils/health/biology/?cid=nrcs142p2_053866
[6] Moldenke, Andrew R. “Soil Arthropods”. USDA, Natural Resources Conservation Service, 26 March 2018, https://www.nrcs.usda.gov/wps/portal/nrcs/detailfull/soils/health/biology/?cid=nrcs142p2_053861
[7] Pollard, Peter. (27 March 2018) "Microbes and the Missing Carbon Dioxide". Tedx Noosa, [Video File], https://www.youtube.com/watch?v=48UtbgtFKTg 
[8] USDA, Natural Resources Conservation Service “Soil Food Web”. 26 March 2018, https://www.nrcs.usda.gov/wps/portal/nrcs/main/soils/health/biology/ 
[9] Wallenstein, Matthew. "To Restore Our Soils, Feed The Microbes". The Conservation, 27 March 2018, https://theconversation.com/to-restore-our-soils-feed-the-microbes-79616
[10] Zimmerman, Chuck. "General Mills Backing Soil Health Program". Ag-Wired, 27 March 2018, http://agwired.com/2017/04/26/general-mills-backing-soil-health-program/
[11] Pollard, Peter. (27 March 2018) "Microbes and the Missing Carbon Dioxide". Tedx Noosa, [Video File], https://www.youtube.com/watch?v=48UtbgtFKTg