Principles of Terrestrial Ecosystem Ecology

UntitledF. Stuart Chapin, III • Pamela A. Matson Peter M.Vitousek
Principles of Terrestrial Ecosystem Ecology
Second Edition
Illustrated by Melissa C. Chapin
F. Stuart Chapin, III University of Alaska Fairbanks Institute of Arctic Biology Department of Biology & Wildlife Fairbanks, AK, USA [email protected]
Peter M. Vitousek Department of Biological Sciences Stanford University Stanford, CA, USA [email protected]
Pamela A. Matson School of Earth Sciences Stanford University Stanford, CA, USA [email protected]
ISBN 978-1-4419-9503-2 e-ISBN 978-1-4419-9504-9 DOI 10.1007/978-1-4419-9504-9 Springer New York Dordrecht Heidelberg London
Library of Congress Control Number: 2011935993
© Springer Science+Business Media, LLC 2011 All rights reserved. This work may not be translated or copied in whole or in part without the written permission of the publisher (Springer Science+Business Media, LLC, 233 Spring Street, New York, NY 10013, USA), except for brief excerpts in connection with reviews or scholarly analysis. Use in connection with any form of information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed is forbidden. The use in this publication of trade names, trademarks, service marks, and similar terms, even if they are not identified as such, is not to be taken as an expression of opinion as to whether or not they are subject to proprietary rights.
Cover illustrations: Temperate forest in the eastern U.S. (North Carolina), showing a complex multi-layered canopy with sunflecks common in all canopy layers. Cover Photograph courtesy of Norm Christensen
Printed on acid-free paper
v
Preface
Human activities are affecting the global environment in many ways, with
numerous direct and indirect effects on ecosystems. The climate and atmo-
spheric composition of Earth are changing rapidly. Humans have directly
modified half of the ice-free terrestrial surface and use 40% of terrestrial pro-
duction. Our actions are causing the sixth major extinction event in the history
of life on Earth and radically modify the interactions among forests, fields,
streams, and oceans. This book is written to provide a conceptual basis for
understanding terrestrial ecosystem processes and their sensitivity to environ-
mental and biotic changes. We believe that an understanding of ecosystem
dynamics must underlie our analysis of both the consequences and the mitiga-
tion of human-induced changes.
This book is intended to introduce the science of terrestrial ecosystem
ecology to advanced undergraduate students, beginning graduate students,
and practicing scientists from a wide array of disciplines. We define terres-
trial ecosystem ecology to include freshwater ecosystems and their terrestrial
matrix. We also include a description of marine ecosystems to provide a
broader context for understanding terrestrial ecosystems and as a basis for
Earth-System analysis. We provide access to some of the rapidly expanding
literature in the many disciplines that contribute to ecosystem understanding.
This second edition incorporates new material that accounts for both the sub-
stantial scientific advances in ecosystem ecology during the past decade, as
well as the evolution of our own understanding.
The first section of this book provides the context for understanding eco-
system ecology. We introduce the science of ecosystem ecology and place it
in the context of other components of the Earth System – the atmosphere,
ocean, climate and geological systems. We show how these components
affect ecosystem processes and contribute to the global variation in terrestrial
ecosystem structure and processes. In the second section of the book we consider
the mechanisms by which terrestrial ecosystems function and focus on the
flow of water and energy and the cycling of carbon and nutrients. We then
consider the important role of organisms in ecosystem processes through
trophic interactions (feeding relationships), environmental effects, and distur-
bance. The third section of the book addresses temporal and spatial patterns
in ecosystem processes. We finish by considering the integrated effects of
these processes at the global scale and their consequences for sustainable use
by human societies. Powerpoint lecture notes that include the illustrations in
vi Preface
this book are available on the web (http://terrychapin.org/) as supplementary
material.
Many people have contributed to the development of this book. We particu-
larly thank our families, whose patience has made the book possible, our
students from whom we have learned many of the important ideas that are
presented, and Hal Mooney who was a co-author of the first edition. In addi-
tion, we thank the following individuals for their constructively critical review
of chapters in this book: Richard Bardgett, Dan Binkley, Dave Bowling,
Pep Canadell, Mimi Chapin, Doug Cost, Joe Craine, Wolfgang Cramer, Eric
Davidson, Sandra Díaz, Jim Elser, Eugenie Euskirchen, Valerie Eviner, Noah
Fierer, Jacques Finlay, Doug Frank, Mark Harmon, Sarah Hobbie, Dave
Hooper, Bob Howarth, Ivan Janssens, Julia Jones, Bill Lauenroth, Joe
McFadden, Dave McGuire, Sam McNaughton, Russ Monson, Deb Peters,
Mary Power, Steve Running, Josh Schimel, Ted Schuur, Tim Seastedt, Mark
Serreze, Phil Sollins, Bob Sterner, Kevin Trenberth, Dave Turner, Monica
Turner, Diana Wall, John Walsh. We also thank Julio Betancourt, Scott
Chambers, Norm Christensen, Greg Cortopassi, Steve Davis, Sandra Díaz,
Jack Dykinga, Jim Elser, Jim Estes, Peter Franks, Mark Harmon, Al Levno,
Mike Kenner, Alan Knapp, Aaryn Olsson, Roger Ruess, Dave Schindler, and
David Tongway for the use of their photographs. We particularly thank Joe
Craine and Dana Nossov for their constructive comments on the entire book.
Fairbanks, AK, USA F. Stuart Chapin, III
Stanford, CA, USA Pamela A. Matson
Stanford, CA, USA Peter M. Vitousek
vii
Contents
Introduction .................................................................................... 3
Ecosystem Processes ................................................................. 11
Human-Induced Ecosystem Change .............................................. 17
Summary ........................................................................................ 21
Introduction .................................................................................... 23
The Atmospheric System ............................................................... 26
Atmospheric Structure .............................................................. 28
Atmospheric Circulation ........................................................... 30
The Ocean ...................................................................................... 35
Ocean Structure ......................................................................... 35
Long-Term Changes .................................................................. 41
Storms and Weather .................................................................. 50
and Structure .................................................................................. 50
Introduction .................................................................................... 63
Parent Material .......................................................................... 64
Additions to Soils ...................................................................... 73
Soil Physical Properties............................................................. 82
Overview of Ecosystem Water Budgets ......................................... 100
Water Inputs to Ecosystems ........................................................... 101
Water Movements Within Ecosystems .......................................... 102
Water Movement from the Canopy to the Soil .......................... 102
Water Storage and Movement in the Soil .................................. 104
Water Movement from Soil to Roots ........................................ 105
Water Movement Through Plants.............................................. 106
ixContents
Changes in Storage .................................................................... 118
Introduction .................................................................................... 123
Biochemistry of Photosynthesis ..................................................... 125
Terrestrial Photosynthesis .............................................................. 134
C 4 Photosynthesis ...................................................................... 136
Crassulacean Acid Metabolism ................................................. 137
CO 2 Limitation .......................................................................... 137
Water Limitation ....................................................................... 145
Temperature Effects .................................................................. 147
Satellite-Based Estimates of GPP ............................................. 153
Summary ........................................................................................ 155
x Contents
Environmental and Species Controls Over NPP ....................... 169
Allocation ....................................................................................... 172
Diurnal and Seasonal Cycles of Allocation .............................. 174
Tissue Turnover .............................................................................. 175
Biome Differences in Biomass .................................................. 177
Biome Differences in NPP ........................................................ 178
Summary ........................................................................................ 180
Introduction .................................................................................... 183
Leaching of Litter .......................................................................... 185
Temporal Pattern ....................................................................... 190
Vertical Distribution .................................................................. 193
Microbial Community Composition
Heterotrophic Respiration .............................................................. 206
Gaseous Carbon Fluxes ............................................................. 214
Particulate Carbon Fluxes ......................................................... 217
Dissolved Carbon Fluxes .......................................................... 217
Stream Carbon Fluxes .................................................................... 217
Summary ........................................................................................ 227
Introduction .................................................................................... 229
Diffusion.................................................................................... 238
Mycorrhizae .............................................................................. 243
Senescence ................................................................................ 254
Herbivory .................................................................................. 255
Summary ........................................................................................ 256
Marine Nutrient Cycling ................................................................ 261
Large-Scale Nutrient Cycles ..................................................... 261
Biological Nitrogen Fixation..................................................... 267
Overview of Mineralization ...................................................... 271
xii Contents
Temporal and Spatial Variability ............................................... 280
Pathways of Nitrogen Loss ............................................................ 281
Gaseous Losses of Nitrogen ...................................................... 281
Solution Losses ......................................................................... 285
Nitrogen and Phosphorus Cycling in Agricultural Systems .......... 293
Summary ........................................................................................ 295
Controls Over Energy Flow through Ecosystems .......................... 300
Bottom-Up Controls .................................................................. 300
Top-Down Controls ................................................................... 305
Ecological Efficiencies ................................................................... 307
Consumption Efficiency ............................................................ 308
Assimilation Efficiency ............................................................. 312
Production Efficiency ................................................................ 313
Introduction .................................................................................... 321
Effect Functional Types ................................................................. 324
Species Effects on Biophysical Processes ................................. 327
Species Effects on Trophic Interactions .................................... 328
Species Effects on Disturbance Regime .................................... 329
Response Functional Types ............................................................ 330
Functional Matrix of Multiple Traits ........................................ 332
Linkages Between Response and Effect Traits ......................... 332
Diversity as Insurance ............................................................... 333
Summary ........................................................................................ 335
Alternative Stable States ........................................................... 340
Disturbance Regime .................................................................. 349
Carbon Balance ......................................................................... 356
Nutrient Cycling ........................................................................ 360
Trophic Dynamics ..................................................................... 362
Summary ........................................................................................ 365
Introduction .................................................................................... 369
Detection and Analysis of Spatial Heterogeneity ..................... 372
State Factors and Interactive Controls....................................... 373
Community Processes and Legacies ......................................... 373
Disturbance ............................................................................... 373
Atmospheric Transfers .............................................................. 384
Disturbance Spread ................................................................... 388
Extensification ........................................................................... 389
Intensification ............................................................................ 391
Summary ........................................................................................ 396
Introduction .................................................................................... 401
Anthropogenic Changes in the Water Cycle ............................. 405
Consequences of Changes in the Water Cycle .......................... 405
The Global Carbon Cycle .............................................................. 407
Carbon Pools and Fluxes ........................................................... 407
Changes in Atmospheric CO 2 ................................................... 409
Marine Sinks for CO 2 ................................................................ 411
Terrestrial Sinks for CO 2 ........................................................... 412
CO 2 Effects on Climate ............................................................. 413
The Global Methane Budget ..................................................... 413
The Global Nitrogen Cycle ............................................................ 414
Nitrogen Pools and Fluxes ........................................................ 414
Anthropogenic Changes in the Nitrogen Cycle ........................ 415
The Global Phosphorus Cycle ....................................................... 417
Phosphorus Pools and Fluxes .................................................... 417
Anthropogenic Changes in the Phosphorus Cycle .................... 419
The Global Sulfur Cycle ................................................................ 419
Summary ........................................................................................ 421
Introduction .................................................................................... 423
Sustainability ............................................................................. 425
Conceptual Framework for Ecosystem Management .................... 432
Sustaining Soil Resources ......................................................... 432
Forest Management ................................................................... 436
Fisheries Management .............................................................. 436
Socioeconomic Contexts of Ecosystem Management ................... 439
Meeting Human Needs and Wants ............................................ 439
Managing Flows of Ecosystem Services ................................... 440
Addressing Political Realities ................................................... 442
Sustainable Development: Social–Ecological
3F.S. Chapin, III et al., Principles of Terrestrial Ecosystem Ecology,
DOI 10.1007/978-1-4419-9504-9_1, © Springer Science+Business Media, LLC 2011
Ecosystem ecology studies the links between
organisms and their physical environment
within an Earth-System context. This chapter
provides background on the conceptual frame-
work and history of ecosystem ecology.
Introduction
between organisms and their environment as
an integrated system. The ecosystem approach
is fundamental to managing Earth’s resources
because it addresses the interactions that link
biotic systems, of which people are an integral
part, with the physical systems on which they
depend. The approach applies at the scale of
Earth as a whole, the Amazon River basin, or a
farmer’s field. An ecosystem approach is critical
to the sustainable management and use of
resources in an era of increasing human popula-
tion and consumption and large, rapid changes in
the global environment.
promoted an ecosystem approach, including
humans, for conserving biodiversity rather than
the more species-based approaches that predomi-
nated previously. There is growing appreciation
for the role that species interactions play in the
functioning of ecosystems (Díaz et al. 2006).
Important shifts in thinking have occurred about
how to manage more sustainably the ecosystems
on which we depend for food and fiber. The supply
of fish from the sea is now declining because
fisheries management depended on species-based
stock assessments that did not adequately con-
sider the resources on which commercial fish
depend (Walters and Martell 2004). A more holis-
tic view of managed systems can account for the
complex interactions that prevail in even the
simplest ecosystems. There is also a growing
appreciation that a thorough understanding of
ecosystems is critical to managing the quality and
quantity of our water supplies and in regulating
the composition of the atmosphere that determines
Earth’s climate (Postel and Richter 2003).
A Focal Issue
increased more in the last half-century than in
the entire previous history of the planet (Steffen
et al. 2004), often with unintended detrimental
effects. Forest harvest, for example, provides
essential wood and paper products (Fig. 1.1). The
amount and location of harvest, however, influ-
ences other benefits that society receives from for-
ests, including the quantity and quality of water in
headwater streams; the recreational and aesthetic
benefits of forests; the probability of landslides,
insect outbreaks, and forest fires; and the potential
of forests to release or sequester carbon dioxide
(CO 2 ), which influences climatic change. How can
ecosystems be managed to meet these multiple
(and often conflicting) needs? In the Northwestern
The Ecosystem Concept 1
U.S., for example, timber was harvested in the
second half of the twentieth century more rapidly
that it regenerated. Concern about loss of old-
growth forest habitat for endangered species such
as the spotted owl led to the development of eco-
system management in the 1990s to address the
multiple functions and uses of forests (Christensen
et al. 1996; Szaro et al. 1999). Ecosystem ecology
draws on a breadth of disciplines to provide the
principles needed to understand the consequences
of society’s choices.
Overview of Ecosystem Ecology
organisms and the physical environment pro-
vides a framework for understanding the
diversity of form and functioning of Earth’s
physical and biological processes. Why do trop-
ical forests have large trees but accumulate only a
thin layer of dead leaves on the soil surface,
whereas tundra supports small plants but an
abundance of organic matter at the soil surface?
Why does the concentration of carbon dioxide in
the atmosphere decrease in summer and increase
in winter? What happens to nitrogen fertilizer
that farmers add to their fields but do not harvest
with the crop? Why has the introduction of exotic
grasses to pastures caused adjacent forests to
burn? These are representative of the questions
addressed by ecosystem ecology. Answers to
these questions require an understanding of the
interactions between organisms and their physi-
cal environments – both the response of organ-
isms to environment and the effects of organisms
on their environment. These questions also
require a focus on integrated ecological systems
rather than individual organisms or physical
components.
factors that regulate the pools (quantities) and
fluxes (flows) of materials and energy through
ecological systems. These materials include car-
bon, water, nitrogen, rock-derived elements such
as phosphorus, and novel chemicals such as pes-
ticides or radionuclides that people have added to
the environment. These materials are found in
Fig. 1.1 Patch clear-cutting leads to single-species patches
in a mosaic of 100 to 500-year native Douglas-fir forests in
the Northwestern U.S. The nature and extent of forest
clearing influences ecosystem processes at scales ranging
from single patches (e.g., productivity and species diver-
sity) to regions (e.g., water supply and fire risk) or even
the entire planet (climatic change). Photograph by Al
Levno, U.S. Forest Service
5Overview of Ecosystem Ecology
water, and the atmosphere and in biotic pools
such as plants, animals, and soil microorganisms
(microbes).
and the abiotic pools with which they interact.
Ecosystem processes are the transfers of energy
and materials from one pool to another. Energy
enters an ecosystem when light energy drives the
reduction of carbon dioxide (CO 2 ) to form sugars
during photosynthesis. Organic matter and energy
are tightly linked as they move through ecosys-
tems. The energy is lost from the ecosystem when
organic matter is oxidized back to CO 2 by com-
bustion or by the respiration of plants, animals,
and microbes. Materials move among abiotic
components of the system through a variety of
processes, including the weathering of rocks, the
evaporation of water, and the dissolution of mate-
rials in water. Fluxes involving biotic components
include the absorption of minerals by plants, the
fall of autumn leaves, the decomposition of dead
organic matter by soil microbes, the consumption
of plants by herbivores, and the consumption of
herbivores by predators. Most of these fluxes are
sensitive to environmental factors such as tem-
perature and moisture, and to biological factors
regulating the population dynamics and species
interactions in communities. The unique contri-
bution of ecosystem ecology is its focus on biotic
and abiotic factors as interacting components of a
single integrated system.
many spatial scales. How big is an ecosystem?
Ecosystem processes take place at a wide range
of scales, but the appropriate scale of study
depends on the question asked (Fig. 1.2). The
impact of zooplankton on their algal food might
be studied in small bottles in the laboratory. The
controls over productivity might be studied in
relatively homogeneous patches of a lake, for-
est, or agricultural field. Questions that involve
exchanges occurring over very broad areas
might best be addressed at the global scale. The
concentration of atmospheric CO 2 , for example,
depends on global patterns of biotic exchanges
of CO 2 and the burning of fossil fuels, which are
spatially variable across the planet. The rapid
mixing of CO 2 in the atmosphere averages
across this variability, facilitating estimates of
long-term changes in the total global flux of car-
bon between Earth and the atmosphere (see
Chap. 14).
of lateral transfers of materials. A watershed is a
logical unit to study the impacts of forests on the
quantity and quality of the water that supplies a
town reservoir. A drainage basin, also known as
a catchment or watershed, consists of a stream or
river and all the terrestrial surfaces that drain into
it. By studying a drainage basin, we can compare
the quantities of materials that enter from the air
and rocks with the amounts that leave in stream
water, just as you balance your checkbook. Studies
of input–output budgets of drainage basins have
improved our understanding of the interactions
between rock weathering, which supplies nutri-
ents, and plant and microbial growth, which
retains nutrients in ecosystems (Vitousek and
Reiners 1975; Bormann and Likens 1979; Driscoll
et al. 2001; Falkenmark and Rockström 2004).
The upper and lower boundaries of an ecosys-
tem also depend on the question asked and the
scale that is appropriate to the question. The
atmosphere, for example, extends from the gases
between soil particles to the edge of outer space.
The exchange of CO 2 between a forest and the
atmosphere might be measured a few meters
above the top of the canopy where variation in
CO 2 concentration largely reflects processes
occurring within the forest rather than in upwind
ecosystems. The regional impact of grasslands
on the moisture content of the atmosphere might,
however, be measured at a height of several kilo-
meters above the ground, where the moisture
released by the ecosystem condenses and returns
as precipitation (see Chap. 2). For questions that
address plant effects on water and nutrient
cycling, the bottom of the ecosystem might be the
maximum depth to which roots extend because
soil water or nutrients below this depth are inac-
cessible to plants. Studies of long-term soil devel-
opment, in contrast, must also consider rocks
deep in the soil, which constitute the long-term
reservoir of many nutrients that gradually become
incorporated into surface soils (see Chap. 3).
6 1 The Ecosystem Concept
Ecosystem dynamics are a product of many
temporal scales. The rates of ecosystem pro-
cesses are constantly changing due to fluctuations
in environment and activities of organisms on
time scales ranging from microseconds to mil-
lions of years (see Chap. 12). Light capture during
photosynthesis responds almost instantaneously
to fluctuations in the light that strikes a leaf. At the
opposite extreme, the evolution of photosynthesis
two billion years ago added oxygen to the atmo-
sphere over millions of years, causing the prevail-
ing geochemistry of Earth’s surface to change
from chemical reduction to chemical oxidation
(Schlesinger 1997). Microorganisms in the group
Archaea evolved in the early reducing atmosphere
of Earth. These microbes are still the only organ-
isms that produce methane. They now function in
anaerobic environments such as wetland soils or
Forest ecosystem
1 km
loss from plowed
a
b
c
d
Fig. 1.2 Examples of ecosystems that range in size by ten
orders of magnitude: an endolithic ecosystem in the sur-
face layers of rocks (1 × 10−3 m in height), a forest 1 × 103 m
in diameter, a drainage basin (1 × 10 5 m in length), and
Earth (4 × 107 m in circumference). Also shown are exam-
ples of questions appropriate to each scale
7Overview of Ecosystem Ecology
animal intestines. Episodes of mountain building
and erosion strongly influence the availability of
minerals to support plant growth. Vegetation is
still migrating in response to the retreat of
Pleistocene…