Ok, fine, but what
IS an ecological community??
Biological
Diversity
Structural diversity
Functional diversity
Taxonomic Diversity: Species Richness Vs. Species Diversity
Most commonly used diversity measure:
s
H    pi ln pi
i 1
plot 101
Common name
black cherry
black raspberry
daisy fleabane
deer tongue
dotted smartweed
elderberry
frost grape
hackberry
horseweed
iron weed
jumpseed
nimble will
pokeweed
purple wintercreeper
red mulberry
rough avens
sedges
virginia creeper
white ash
white clover
white mulberry
yellow wood sorrel
Shannon-Weaver Diversity Index
aka
Shannon-Weiner Diversity Index
aka
Shannon Index
trt 1
Scientific name
COVER area p
lnp
plnp
Prunus serotina
2
18 0.026785714 -3.61989 -0.09696
Rubus occidentalis
1
2 0.00297619 -5.81711 -0.01731
Erigeron annuus
2
18 0.026785714 -3.61989 -0.09696
Dichantheliem clandestinum
1
2 0.00297619 -5.81711 -0.01731
Polygonum punctatum
2
18 0.026785714 -3.61989 -0.09696
Sambucus pubens
2
18 0.026785714 -3.61989 -0.09696
Vitis vulpina
2
18 0.026785714 -3.61989 -0.09696
Celtis
1
2 0.00297619 -5.81711 -0.01731
Conzya
1
2 0.00297619 -5.81711 -0.01731
Cyanthillium
1
2 0.00297619 -5.81711 -0.01731
Polygonum virginianum
2
18 0.026785714 -3.61989 -0.09696
Muhlenbergia scheebri
3 180 0.267857143 -1.3173 -0.35285
Phytolacca americana
1
2 0.00297619 -5.81711 -0.01731
Euonymus fortunei
1
2 0.00297619 -5.81711 -0.01731
Morus rubra
3 180 0.267857143 -1.3173 -0.35285
Geum laciniatum
1
2 0.00297619 -5.81711 -0.01731
Carex
Parthenocissus quinquefolia
3 180 0.267857143 -1.3173 -0.35285
Fraxinus americana
1
2 0.00297619 -5.81711 -0.01731
Trifolium repens
1
2 0.00297619 -5.81711 -0.01731
Morus alba
1
2 0.00297619 -5.81711 -0.01731
Oxalis europaea
1
2 0.00297619 -5.81711 -0.01731
672
1 -95.4766 -1.84807
Some general patterns of biodiversity
Some general patterns of biodiversity (in your book, figure19.12)
Tree species richness as measured in 2.5°  2.5° quadrats across
North America
Some general patterns of biodiversity (figure 19.6, in your book) The state of Wisconsin, showing
the ecological divisions and provinces defined by Curtis
19.2 Plant species richness along an elevational gradient in the Santa Catalina Mountains
Biodiversity concepts
Concept # 1:
Species –Area Relationship.
Concept # 2:
Alpha, Beta and Gamma Diversity
Concept # 3:
Disturbance – Diversity Relationship.
Concept # 4:
Productivity - Diversity Relationship.
Concept # 5:
Biodiversity- Ecosystem Function
Community properties: Species-Richness & Species Area Relationships
Biodiversity concepts
Concept # 1:
Species –Area Relationship.
Concept # 2:
Alpha, Beta and Gamma Diversity
Concept # 3:
Disturbance – Diversity Relationship.
Concept # 4:
Productivity - Diversity Relationship.
Concept # 5:
Biodiversity- Ecosystem Function
Alpha diversity, Beta and Gamma Diversity…
Kinds of diversity….
- alpha
- beta
- gamma
Biodiversity concepts
Concept # 1:
Species –Area Relationship.
Concept # 2:
Alpha, Beta and Gamma Diversity
Concept # 3:
Disturbance – Diversity Relationship.
Concept # 4:
Productivity - Diversity Relationship.
Concept # 5:
Biodiversity- Ecosystem Function
Biodiversity concepts
Concept # 1:
Species –Area Relationship.
Concept # 2:
Alpha, Beta and Gamma Diversity
Concept # 3:
Disturbance – Diversity Relationship.
Concept # 4:
Productivity - Diversity Relationship.
Concept # 5:
Biodiversity- Ecosystem Function
What is productivity?
The concept of “productivity” in ecology is related to the use of the term in other fields
such as agriculture, or even manufacturing. How much material is being produced in a site.
In agriculture, you can easily measure the amount of some material coming from a site
(e.g., and discuss the productivity of that site). In ecology, productivity is a bit more
difficult to measure, and the general idea is the total volume of biomass (woody material,
leaves, etc) that is being produced on a given site, during a given time frame. For
productivity you need volume, area & time.
One way to think about it is if you apply fertilizer to your lawn, that will probably cause the
grass to grow faster. If you add fertilizer at different rates to different areas of the lawn and
then clipped the grass, and measured the grass, you could get a sense of the amount of
productivity in the law, and how it is influenced by the fertilizer.
In ecosystems you can think about natural variation in productivity. If the site is protected
from the sun, it might dry out less, and have more water and thus vegetation can grow
faster. There are also gradients in soil fertility across the landscape. Often, ecologists will
talk about “high productivity site” vs. a “low productivity site” and what they are talking
about is, basically, a summation of all the factors that contribute to plant growth on a
particular site. Some species do better on low productivity sites. Some do better on high
productivity sites.
Okay then….what about diversity and productivity?
The question has arisenconcept of “productivity” in ecology is related to the use of the term
in other fields such as agriculture, or even manufacturing. How much material is being
produced in a site. In agriculture, you can easily measure the amount of some material
coming from a site (e.g., and discuss the productivity of that site). In ecology, productivity
is a bit more difficult to measure, and the general idea is the total volume of biomass
(woody material, leaves, etc) that is being produced on a given site, during a given time
frame. For productivity you need volume, area & time.
One way to think about it is if you apply fertilizer to your lawn, that will probably cause the
grass to grow faster. If you add fertilizer at different rates to different areas of the lawn and
then clipped the grass, and measured the grass, you could get a sense of the amount of
productivity in the law, and how it is influenced by the fertilizer.
In ecosystems you can think about natural variation in productivity. If the site is protected
from the sun, it might dry out less, and have more water and thus vegetation can grow
faster. There are also gradients in soil fertility across the landscape. Often, ecologists will
talk about “high productivity site” vs. a “low productivity site” and what they are talking
about is, basically, a summation of all the factors that contribute to plant growth on a
particular site. Some species do better on low productivity sites. Some do better on high
productivity sites.
13.8 The relationship between productivity and species richness can have different shapes in
different communities
Why?
One idea- at low levels of
productivity (~nutrient
availability) not many
species can persist. As
productivity increases,
more species can live in
the site
13.8 The relationship between productivity and species richness can have different shapes in
different communities
Why?
As you increase the level
of productivity, some
species, that are the best
competitors, will become
dominant. They can
eliminate some other
species
13.8 The relationship between productivity and species richness can have different shapes in
different communities
Why?
If you put these
two ideas together,
you get a unimodal
relationship
13.7 Experimental fertilization of 72 plots in an old field in NW Pennsylvania (Part 1)
Concept # 1: Influence of
local productivity on local
patterns of biodiversity.
Hump-backed productivitydiversity curve.
Diversity
3.0
April
Diversity (H´)
2.5
2.0
1.5
1.0
0.5
0.0
3.0
June
L
Diversity (H´)
2.5
McEwan data. Herbaceous
species in a temperate, oldgrowth forest.
2.0
1.5
1.0
0.5
0.0
3.0
August
Diversity (H´)
2.5
2.0
1.5
1.0
0.5
0.0
0
5000
10000
15000
20000
25000
Productivity (cover cm2/m2)
30000
35000
13.9 Percentage of studies showing various relationships (Part 1)
19.5 Percentage of studies showing various relationships between productivity and vascular plant
species richness at different geographic scales
How do disturbance and productivity relate to one another
as predictors of biodiversity?
How do disturbance and
productivity relate to one another?
The Dynamic Equilibrium Model of
diversity of Huston (1979). You
read this figure like a topographic
map, where the orange is the peak.
So there is a peak in diversity at
intermediate levels of both diversity
and productivity. In restoration
projects you may have gradients in
both productivity and diversity.
Biodiversity concepts
Concept # 1:
Species –Area Relationship.
Concept # 2:
Alpha, Beta and Gamma Diversity
Concept # 3:
Disturbance – Diversity Relationship.
Concept # 4:
Productivity - Diversity Relationship.
Concept # 5:
Biodiversity- Ecosystem Function
Biodiversity- Ecosystem Function Relationship
Is there a generalized relationship between diversity and
ecosystem function in restoration?
Concepts
Niche Complementarity: This is an idea about the relationship among species in creating or
perpetuating some ecosystem property. One way to illustrate this is to think about species
fitting together sort of like puzzle pieces. As you add species the picture gets clearer…in the
analogy, as you add species to the ecosystem, its functionality increases accordingly. One
example that is currently ‘hot’ is the idea that as you add tree species to a forest, that forest’s
capacity to capture and sequester carbon increases.
This concept carries a whole load of assumptions with it…and it certainly has not been clearly
proven for all systems and/or all ecosystem functions. If Niche Complementarity is occurring,
you would expect a linear relationships between the function and species diversity- as you add
species- the function linearly increases.
One outstanding issue is whether apparent (NC) is because of increasingly filled niche space or
whether you just happen to pick up a species that is good at that particular job as you add
species (aka, Sampling Effect). This issue is very much alive in Ecology right now.
Concepts
Functional Groups: There are a lot of species in the world. A LOT. In many
cases it is very difficult, if not impossible, to address this diversity from a scientific
perspective, much less from the perspective of management. One way to simplify
this diversity is to focus on an individual’s functions, rather than its taxonomy (i.e.,
its evolutionary relationship to other organisms). If you can “bin” species
depending on function then management or restoration could, potentially, focus on
functional groups. Some examples include “vernal herbs,” and nitrogen fixing
plangs
Concepts
Species Redundancy: If we think about species as functional participants in ecosystemsproviding a specific capacity/outcome/function, it can lead to the idea that some (or maybe
even many) species are providing identica l, or at least measurably similar, attributes to the
system.
Thus, the idea of species redundancy.
But, don’t think of this in a negative context…like there are useless species in an ecosystem.
Instead, thinking about it from this perspective allows the identification of species that are
MORE crucial to preserve/restore…those that provide a specific function when no other
species do. Some examples, for instance, N-fixing plants, or maybe a shredding insect.
From a biodiversity management perspective one goal me be create or maintain redundancy,
to make the ecosystem more stable.
Biodiversity, ecosystem function, and
functional diversity, some ideas…
Biodiversity- Ecosystem Function Relationship
Is there a generalized relationship between diversity and
ecosystem function?
Hooper, David U., and Peter M. Vitousek. "The effects of
plant composition and diversity on ecosystem processes."
Science 277.5330 (1997): 1302-1305.
biodiversity