Download Understanding Wetland Niches

Understanding Wetland Niches
Determining Niches of Plant Species in Saline Wetlands
Challenges of Living in a Salt Marsh
A. Defining Abiotic Characteristics of Salt Marshes
1. Hydrology - saturated by water for at least all or part of the year
2. Soil - mostly waterlogged clay soils
3. Salinity - organisms must cope with salt
B. Wetland Plant Adaptations
1. Plants - adapted to grow saturated by water
• hollow passages from leaves to roots for air movement
• oxidation of the surrounding soil
• reversing osmotic flow by salt concentration
• excretion of salt by glands on leaves and stems
What happens when organisms rely
on the same resources?
competition = interactions between organisms
using the same resources - often in short supply
Principle of Competitive Exclusion
If two species are in competition for the same
limited resource, one will be eliminated in
situations where they occur together.
© 2004 Brooks/Cole – Thomson Learning
Number of individuals
Principle of Competitive Exclusion
Species 1
Species 2
Region
of
niche overlap
Number of individuals
Resource use
Species 1
Species 2
Resource use
How can similar species coexist in
natural communities?
ecological niche = role played by an organism
the way it makes its living
(niche = “occupation” habitat = “home”)
resource partitioning = coexisting species use
slightly different portions of an available
resource.
examples:
The colored
areas indicate
Cape May
Bay-breasted
Blackburnian
the feeding
Warbler
Warbler
zones of these Warbler
five species of
N. American
Warblers. The
partitioning of
resources
allows all
species to feed
“Myrtle”
Black-throated
off the same
Warbler
green Warbler
tree.
Fundamental Niche = niche occupied by an
organism in absence of competition.
Realized Niche = portion of the fundamental
niche actually utilized.
examples:
Smaller organisms are typically able to exploit
more niches.
High Tide
Realized
Niches
Fundamental
Niches
Chthamalus
barnacles
Ocean
Balanus barnacles
Low Tide
Niche Overlap
A. Definition - locations where two or more species are present
1. How can two or more species occupy the same realized niche?
Niche Breadth
Specialists vs. Generalists
Matt Goo, 2007
The Effect of
Distance From Water On Percent Cover
Percent Cover
120
cord grass
algae
salt grass
pickleweed
salt bush
upland
fennel
100
80
60
40
20
0
0
1
2
3
4
5
6
7
8
9 10 11 12 13
Distance From Water(Meters)
Realized Niches of Salt Marsh Plants
(Generalized)