NREM 301
Reading Guide
Chapters 1 & 2
Reading guides will be provided for each of the assigned chapters in the textbook. The
important material in the chapters and the parts of the chapter for which you are not responsible
will be identified.
NOTE: You will not be asked to hand in answers to all of the reading guides – however, reading
guides will have activities in them that will help you process the information. At the end of the
assigned time for reading the chapter we may have a quiz, in class covering the material
covered in the reading guide. The quiz could cover both specifics in the guide and/or provide
situations from the lab or other discussions for you to process using the information from the
guide. (The answers to the questions on page 6-8 will be handed in for this guide on
Thursday, September 3, 2009)
You will receive another reading guide early next week for chapters 3 and 4 – please be
prepared for an in-class group quiz over material covered in these 4 chapters, our
lecture and lab on Thursday, September 3, 2009.
Chapter 1 Introduction
While the text book covers mainly forest ecosystems we will also be discussing prairie,
savanna, wetland and stream ecosystems both in their natural and disturbed
(agriculture) states during the semester. We are taking a broader landscape look at ecology
so interactions between all of these ecosystems is as or more important than the functions
within any one of them alone. We would like you to be prepared to define, give examples and
discuss the functions, services, and responses to human activities for the following terms. As
we visit each of the different ecosystems during the semester be sure that you can apply these
terms from Chapter 1 to each of them.
Cycling
Communities
Ecosystem
Function
Redundancy
Keystones
Synergy
Stability
Diffuse boundaries
Hierarchiacal structure
Ripple effect
Ecosystem services
Forest stand
Landscape ecosystems
Vertical Stratification
Horizontal Stratification
Edge
Ecotone
Cover Type
Phenotype/Genotype
Site
Physiography
Silviculture
The first two paragraphs of Chapter 1 establish several very important concepts.
Organisms don’t live in isolation, most depend on sunlight as their ultimate source of energy,
the earth is a spaceship with finite resources so to sustain life many of these resources have to
be used over and over again (cycled), no single species can capture energy and at the same
time cycle matter so they are found grouped together into communities. Be prepared to expand
on each of these with concrete examples from what you presently know, from further examples
in the book and from the field labs we are going to be conducting.
Be prepared to give a definition and examples of an ecosystem and be sure you can
differentiate them from communities.
Be prepared to discuss and provide examples of the four distinguishing characteristics of
ecosystems: 1) a web of interactions and interdependencies among the parts; 2) synergy;
3) stability; and 4) diffuse boundaries. Make sure you understand how redundancy and
keystones are used in describing these characteristics and why stability does not mean “no
change” and how ecosystems are part of a hierarchical structure that is related to temporal and
spatial scales.
The authors state that “understanding ecosystems is prerequisite to keeping them
healthy and productive” in other words to manage any ecosystem we must understand it
structure and function – how it works. The authors refer to the importance of the “ripple
effect” at spatial scales that go from the local set of neighboring plants to the globe. In the box
on page 3 they describe the ripple effect of thinning. Be prepared to discuss this and to apply
this discussion to an agricultural landscape where “thinning” has resulted in the complete
replacement of the perennial plant community by annual communities or by very simplified
perennial communities that are now grazed – what ripple effects do you think have taken
place because of these changes?
The second major reason for understanding ecosystems is that the society is demanding
that the forests and any other perennial ecosystem be managed for many potentially
conflicting purposes. This introduces us to the concept of ecosystem services. Note the
ones that the authors present and be prepared to discuss their importance and be ready to list
others as well.
Be prepared to describe the specifics presented on the services that forests play in
capturing solar energy, influencing the head balance, in providing rainfall, in acting as
the major source of the world major rivers and in acting to conserve soils. Also be
prepared to discuss their services in terms of the recreation potentials they provide and the
aesthetic, spiritual and medicinal impacts they have on people.
The authors present a section on the State of the World’s Forests. What I would like you to get
out of this section is a feeling for the magnitude of change over the last century, where the
change has taken place, what the nature of the change has been – what has replaced forests
where they have been removed, what the impacts of that change has been and what if any
positive signs there are of the negative change of deforestation being reversed. While the
authors spend most of their effort talking about changes around the world, I would like you
again to focus on what changes have taken place here in Iowa and the Midwest with the
deprairieization (my word) – what are the parallels with deforestation – what is the long-term
prognosis for this change over 80+% of Iowa – what positive signs are there of trying to mitigate
some of the changes that have been brought about?
Chapter 2 Basic Terminology and Concepts
Terms you should be able to define and use from Chapter 2
Population
Metapopulation
Community
Biocoenosis
Metacommunity
Ecosystem
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Metaecosystem
Biogeocoenosis
Succession
Foreign Disturbances
Ecology
Primary & Secondary Productivity
Food webs
Stability
Sustainability
Ecosystem Services
Feedback (positive & negative)
Density-Dependent Controls
Mutualism
Pattern
This chapter begins with an interesting concept that we will harp on throughout the semester –
it basically says that there are no absolutes – note how the authors differentiate between a
definition and a concept – a definition being something you can put boundaries around and a
concept something with no clear boundaries, more abstract notions. As the authors suggest,
many of the terms used in ecology are concepts rather than objects and so are not suited to
rigorous definition. We will mention many times during the semester, that there are numerous
and varying ways to approach an issue or explain a situation in field settings.
Please note the critical concepts of interaction that help define a population – note why a
group of organisms is designated as a population and how one population differs from another.
Also note the difficulty in some settings of identifying populations (see box on page 12). As you
consider populations think of the role that fragmentation plays in creating populations – think of
the few prairie remnants that exist in central Iowa – do these support one or more populations
of individual species such as big bluestem (Andropogon gerardii) – if not might they all have
been part of a population 250 years ago?
Please be prepared to differentiate between a population and a community in our field labs.
Note that the general terms forest or prairie are often used synonymously with community. This
is very important for professionals to remember – often foresters or prairie professionals think
of their communities in terms of only the dominant plants, the trees or native grasses and some
forbs, when in fact a community is much more than that. Note that the term community can be
used to describe a specific assemblage of plants and animals on a specific portion of the
landscape or it can be used more abstractly to describe a type of assemblage – example in the
text – mixed conifer community. Begin to think of the myriad of interactions that take place at
the community level in a landscape setting – the movement of energy, organisms and materials
that make up ecosystems.
Note the hierarchical nature of moving from a population to a community and then to an
ecosystem – what has been added to the concept of an ecosystem? Be prepared to describe
these additions in the field. Note the neat example that the authors use to describe the
functions in an ecosystem – “not just a set of organisms and molecules; like a friendship
between two people, it is a complex of interactions.” Note what four things must be occurring to
have a viable ecosystem – think especially about the mechanisms for storing and recycling –
these are interactions that humans have greatly modified and that we will spend a lot of time
talking about in this class. We will also spend a lot of time discussing the mechanisms that
allow an ecosystem to persist – very important when we conservation professionals attempt to
establish isolated perennial plant communities into a landscape matrix of corn and soybeans.
Be prepared to discuss the importance of disturbance to maintenance of ecosystem health and
how disturbance leads to succession and the difference between natural disturbances that
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ecosystems have evolved with and foreign disturbances that are not part of the past history of
an ecosystem.
Make sure to read the box in the right-hand column of page 13. Think of how actions in the
cornbelt of the Midwest influence the hypoxia zone (dead zone) in the Gulf of Mexico near the
mouth of the Mississippi.
Note the concern that the authors have with the definition of ecology as the study of the
relationships between organisms and their environment. Why don’t they like that definition –
what do they say about the role of humans in ecology?
For the section on Subdisciplines of Ecology I would like you to develop a general idea of the
differences between the subdisciplines – they tend to follow the subdivisions of basic concepts
that we have been talking about. I would like you to pay special attention to the Ecosystem and
Landscape Ecology units as we will spend most of our time in these arenas. We will have a
unit on Physiological Ecology when we describe the basic structure and function of a woody
plant and we will have general discussions that center on Earth Systems Science and Ecology
for a Crowded Planet. Please pay attention to the structural and functional attributes of an
ecosystem as a whole (page 15). Notice under Earth Systems that the authors include the
present strong interest and discussion of sustainability – sustainable landscape, sustainable
agriculture, etc. Also note under Ecology for a Crowded Planet that the authors mention
ecosystem services and designated ecological solutions.
In section 2.3 The Nature of Systems (page 16) I would like you to focus your attention on the
two concepts of feedback and pattern. Be prepared to give examples of positive and negative
feedbacks. Note that positive feedbacks have a destructive potential which is constrained by
negative feedback two examples being “resource limitations” and “predation” (second column,
page 18) – think about this and be prepared to give examples – also read the provocative box
on page 18 and think about the consequences for the sustainability of the human population on
our planet. Note that the authors use pattern, information, syntax and structure
interchangeably. What do they mean by those? The examples they give on chemical
messengers and language definitely refer to information and pattern but pattern and structure
go much further than that and as they suggest in the last sentence of this section we will spend
a lot of time talking about pattern and structure in this class – think about what that means in an
ecosystem sense.
Forests provide these & other ecosystem services: (Be prepared to make a similar list for
prairie, wetland & aquatic ecosystem)
 Occupy 15% of the earth’s surface (including oceans) but capture 50% of the total solar
energy caught by plants.
 Low albedo (reflection) helps maintain energy balance.
 Forests contain large amounts of sequestered carbon that control global warming.
 Forests are a major source of evaporation from land that helps distribute precipitation
globally.
 Major droughts and desserts around the world may result from deforestatiton.
 Most of the world’s major rivers start in forests or what where once forests.
 Provide medicinal plants (anticancer properties of western yew and the Madagascar
periwinkle).
 Forests are one of the truly wild places on earth and an important spiritual tie for
humans.
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NREM 301
Chapters 1 & 2 Reading Guide Exercises
Due September 1, 2009
1. In Chapter 1 the authors identify 4 distinguishing characteristics of ecosystems. Please
prepare a ½ page – typed reflection of the differences you would expect to find between a
native prairie ecosystem like we visited in lab and a row crop ecosystem like those that
surround the Doolittle prairie.
2.
Please read the last paragraph before the box in column 2 on page 19. Reflect on the last
three sentences in the paragraph and write a paragraph (½ page typed) on how this relates
to the massive conversion of the native prairie here in Iowa and the cultivation patterns used
today to raise corn and soybeans. We are interested in your take on the level of activity
farmers expend in their farm fields that are needed to maintain the “way the system is put
together – its syntax”. If that level of effort were not expended what do you think would
happen to those row crop ecosystems?
3. Physiological Ecology Question - Consider a tree or prairie grass plant. Most terrestrial
plants live in two distinct environments, those being the air and the soil. Compare the major
differences between the air and soil that the plant has to deal with and then mention briefly
how the plant adapts to these differences in the two environments. (Please use single
descriptive words or phrases – no long sentences)
Parameter
Air
Soil
Temperature range &
Variability
Moisture (kind, delivery,
variability)
Density/mass of media
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Plant adaptations
Movement of media
Other organisms
4. As discussed in the text (page 18) ecosystem pattern is interchangeable with ecosystem
structure. Pattern and feedback are two very important concepts for understanding
biological systems. Stratification is a major component of structure. As you move up
vertically up and down within an ecosystem you may encounter various strata of plants
or soil horizons or organic litter layers, etc. As you move horizontally across an
ecosystem you also experience different stratified structures. In the picture below
describe the differences in vertical and horizontal stratification that you would expect to
see as you moved from left to right along the line that is drawn. What kinds of strata do
you see in a vertical direction (remember to consider down into the water & into mineral
soil) and what kinds in a horizontal direction?
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