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- Herausgeber: John Wiley & Sons
- Kategorie: Fachliteratur
- Sprache: Englisch
Forest Ecology
Forest Ecology
An Evidence-Based Approach
Forest ecology is the science that deals with everything in forests, including plants and animals (and their interactions), the features of the environment that affect plants and animals, and the interactions of humans and forests. All of these components of forests interact across scales of space and time. Some interactions are constrained, deterministic, and predictable; but most are indeterminant, contingent, and only broadly predictable.
Forest Ecology: An Evidence-Based Approach examines the features common to all forests, and those unique cases that illustrate the importance of site-specific factors in determining the structure, function, and future of a forest. The author emphasizes the role of evidence in forest ecology, because appealing, simple stories often lead to misunderstandings about how forests work. A reliance on evidence is central to distinguishing between appealing stories and stories that actually fit real forests.
The evidence-based approach emphasizes the importance of real-world, observable science in forests. Classical approaches to ecology in the twentieth century often over-emphasized appealing concepts that were not sufficiently based on real forests. The vast amount of information now available on forests allows a more complete coverage of forest ecology that relies on a strong, empirical foundation.
Forest Ecology: An Evidence-Based Approach is the ideal companion text for the teaching of upper-level undergraduate and graduate courses in forest ecology.
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Seitenzahl: 751
Veröffentlichungsjahr: 2021
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Table of Contents
Cover
Title Page
Copyright Page
Dedication Page
Preface
How Do We Come to Understand Forests?
How Confident Should You Be?
All Forest Ecology Fits Into a Framework and a Method
A Picture May Be Worth 1000 Words, But a Graph Can Be Worth Even More
The Most Important Points to Understand from Figures B and C Are Not About Precipitation or Temperature
Confidence Bands Around Trends Come in Two Types
The Stories in This Book Have Two Pieces, Told in Three Ways
Forests Are Complex Systems That Are Not Tightly Determined
Acknowledgements
CHAPTER 1: The Nature of Forests
Forest Ecology Deals with Individual Trees Across Time
Many Processes Occur in a Tree Every Hour
Tree Physiology Follows Daily Cycles
Trees Must Cope with Seasonal Cycles Through Each Year
Trees Grow and Reproduce at Times Scales of a Century
The Story of Forests Is More than the Sum of the Individual Trees, Because Interactions Are So Strong
The Coweeta Forests Aren't the Same as Two Centuries Ago
Across Dozens of Generations of Trees, Almost Everything Changed at Coweeta
The Futures of the Tree and the Forest Will Depend on Both Gradual, Predictable Changes and Contingent Events
Ecological Afterthoughts: Is a Forest an Organism?
CHAPTER 2: Forest Environments
Climate Influences Where Forest Occur, and How They Grow
Warmer Forests Have More Species of Trees
Chemical and Biological Reactions Go Faster with Increasing Temperature
Temperature is the Balance Point Between Energy Gains and Losses
All Objects Shine; Hot Objects Shine Brightly
Incoming Sunlight Decreases in Winter and at Higher Latitudes
Forests Receive Shortwave Sunlight, and Shine off Longwave Radiation
Temperatures Decline with Increasing Latitude
Temperatures Increase at Lower Elevations
Temperature Variation Over Time, and Across Space, Strongly Influences Forest Ecology
Temperature Strongly Influences Phenology and Growth
Forests Use Very Large Amounts of Water
Water Flows Down Gradients of Potential, Which Sometimes Means Going Up
Wind Shapes Trees and Forests
Events and Interactions Are More Important Than Averages and Single Factors
Fires Depend on Temperature, Water, Winds
Droughts Affect Trees, Beetles, Forest Structure and Fire Intensity
Weather Events Can Matter More than Averages
Ecological Afterthoughts
CHAPTER 3: Evolution and Adaptation in Forests
What's in a Name?
The Core Idea of Evolution Is the Combination of Variation, Failure, and Innovation
Darwin Could Not Explain Why Variations Occurred, or Why They Were Passed on to Offspring
Does Selection Work on Species or on Genes, or Is This Only a Chicken‐and‐Egg Question?
Biology Operates from a Simple Story of DNA to Incredible Complexity of Proteins and Biochemistry
Why Are There Only Two Species of Tulip Poplar, and Why Are They 12 000 km Apart?
Tall Growth Requires Strong Stems
The First Trees from Seeds Were Gymnosperms
Collaboration with Insects Helped Angiosperms Take over the Planet
The Highest Diversity Is in Tropical Rain Forests
Do all Trees Need to Have Trunks?
Some Broadleaved Trees Make Fertilizer Out of Thin Air
What's the Largest Tree in the World?
History Has No Need to Repeat Itself
Critchfield Spruce Melted Away at the End of the Last Ice Age
Ponderosa Pine Went from Obscurity to Prominence in Just a Few Thousand Years
Eastern Hemlock Has Had a Dynamic History of Up and Down
Almost all the Animal Species Are Missing from Temperate and Boreal Forests
Climate, Animals and Fire Interact Across Forest Generations
Modern Forests Are Changing Faster Than Ever, on a Global Scale
Ecological Afterthoughts
CHAPTER 4: Physiology and Life History of Trees
Biological Energy Is About Moving Electrons
Forest Energy Comes from Sunlight; Wood Comes from Thin Air
Why Are Leaves Green?
Leaves Are Not Always Green
Carbon Uptake Is the Second Half of Photosynthesis
Growth Happens After Photosynthesis – Sometimes Long After
Trees Do Not Live by Carbon Alone
Photosynthesis and Growth Depend on Acquisition of Resources
More Leaves Means More Light Capture, up to a Point
One Square‐Meter of Leaves Has a Mass of 50–150 g
Each Square Meter of a Forest has Multiple Layers of Leaves above
Large Trees Depend on Large Roots
Networks of Fine Roots Permeate Soils
Do Roots Take Up Water and Nutrients?
Trees (and Mycorrhizal Fungi) Obtain Nutrients by the Interaction of Mass Flow and Diffusion
Life History Is the Story of Going from Seed to Mature Seed‐Producing Tree
Tree Seeds Range in Mass from Smaller than a Flea to Larger than a Mouse
Why Is the Understory of a Forest a Tough Place for Small Trees to Thrive?
All Good Summers Come to an End
Most Trees Die Young
Reproduction Is the Beginning and the End of Life History Stories
Ecological Afterthoughts: What Benefit Comes from Aspen Having Chlorophyll in Its Bark?
CHAPTER 5: Ecology of Wildlife in Forests
Many Species of Trees Coevolved with Animals as Seed Dispersers
Some Animal Species Specialize in Eating Trees
Livestock Grazing and Browsing has been a Core Part of People’s Livelihoods Through History
Was Aldo Leopold Right About the Kaibab Deer Herd?
Wildlife Population Dynamics Occur Within Complex Ecological Systems
Moose and Wolves Established New Populations on Isle Royale in the Early 1900s
The Cycles of Snowshoe Hares and Lynx Repeat, but They Are Far from Simple
Patterns and Processes of Wildlife Population Dynamic Shift Across Space and Time
Good Ideas Without Good Evidence May Be Unreliable, or Wrong
Strong Evidence Comes from Comparisons of Treatments at the Same Point in Time
Ecological Afterthoughts
CHAPTER 6: Forest Soils, Nutrient Cycling, and Hydrology
Forests Need Soils for Physical Support
Soils Here Are Different from Over There, and Soils Now Are Different from Soils Then
Organic Matter is the Top Feature of Soils
Clay Content Comes in Second to Organic Matter
Soils Breathe
The Variety of Soils Is Parsed into Soil Taxonomic Groups
Soils Differ in Age, Even if Most Don't Have Birthdays
Trees Affect Soils
Decomposition Reverses Photosynthesis and Nutrient Uptake
Almost all Forest Biodiversity Is Found in the Soil
Leonardo da Vinci Couldn't Figure out How Water Got to the Top of Mountains
The Atmosphere Holds Only a Few Days of Precipitation
Forest Water Budgets Begin with Precipitation
Water Use by Forests Can Be Measured Across a Range of Scales
Trees Use Most (or All) of the Water
George Perkins Marsh (and Everyone Else) Was Wrong About the Effect of Forest Cutting on Water
Reliable Generalizations Require Evidence from More than One Case
Nutrients Make Life Possible
Nutrients Come From the Atmosphere and From Rocks
Biogeochemical Cycles Are Complex
Decomposition is the Centerpiece of Nutrient Cycling in Forests
Nutrient Losses Are Chronic and Episodic
Ecological Afterthoughts: Consequences of a Warmer World for Snow, Streams, and Forests
CHAPTER 7: Ecology of Growth of Trees and Forests
Forests Are Small and Large, and Growth Is the Key Process Driving Increases
Growth is Examined in a Variety of Ways
Yield Tables Were an Early Example of Parsing Variation in Forests Across Landscapes
Patterns in Yield Tables Were Explained Based on “Growing Space”
Production Ecology Parses Growth into Ecophysiological Factors Constrained by Mass Balance
Forest Growth Is a Function of Resources in the Environment, Resources Acquired, and Efficiency of Resource Use
The Growth of a Forest is the Sum of the Growth of All the Trees
Large Trees Usually Grow Faster than Small Trees in the Same Forest
Dense Forests Have the Highest Growth Rates
Forest Growth Peaks at a Young Age and Then Declines, but Not the Growth of the Biggest Trees in the Forest
Forest Growth Changes over Time, Not Just with Age
Neighbors Influence the Growth of Trees
How Might a Mixed‐Species Forest Grow Faster than a Single‐Species Forest?
Mixed‐Species Forests Usually Cannot Match the Growth of Fast‐Growing Monocultures
When a Species Increases Resource Supplies, Mixtures May (or May Not) Outperform Single‐Species Forests
The Growth of Mixed‐Species Forests Changes over Time
Mixed‐Species Forests Are not Only About Growth Interactions Between Species
Understory Vegetation is Important in Most Forests
Mortality Gets the Final Word on Forest Production
Death is Not the End of the Story for Trees
Ecological Afterthoughts: Is it Better to Remove Small Trees or Large Trees When Thinning a Forest?
CHAPTER 8: Forests Across Space
The Three Most Important Things for a Tree Are Location, Location, and Location
How Small Can a Forest Be?
Forests May Be Divided Into Stands, But Not All Forests Are Structured As Distinct Stands
People Engage with Forests by Defining Areas of Interest
Larger Plots Contain More Species
Vegetation Differs Between Locations
Space Has Another Dimension for Animals
Differences in Forests Usually Increase with Distance, But Not Always
Location Matters Both Locally and Regionally
Resource Use Varies Across Landscape Gradients
Mind the Gap: Spatial Patterns of Trees Within Forests Modify Resource Supplies
The Ecology of Gaps is Not Binary
The Ecology of Gaps and Edges Affects Animals, and Is Shaped by Animals
The Location of Each Tree Allows a Wide Range of Assessments of Forest Structure and Processes
Forest‐Level Information Can Be Dissected Down to the Level of Individual Trees
Riparian Forests Are Special and Important, for Different Reasons in Different Forests
Spatial Patterns Are Important, Even in the Most Uniform Forests
Forest Classification Is Different in the Twenty‐First Century
Ecological Afterthoughts: When It's Not About the Trees
CHAPTER 9: Forests Through Time
Sometimes a Classic Story Comes True
Long‐Term Experimental Forests Provide Knowledge at the Scale of Tree Lifetimes
When Recorded History Is Not Enough, Tree Rings Can Provide a Record of Both Age and Size
Dendrochronology Developed Because There Are No Canals on Mars
Dendrochronology Can Explain Past Forest Structure and Dynamics
Darwin's Ideas Contributed Very Little to Early Ideas of Forest Change (Unfortunately)
Chronosequences Are a Shortcut to the Future, But They May Be Unreliable
Strong Chronosequences Require Large Numbers of Replicates
Growth Always Declines in Old Forests
People Change How Forests Change Over Time
Time Scales of Forests and Human Planning Do Not Always Match
Over the Long‐Term, Forests Have Not Changed As Predicted
Ecological Afterthoughts
CHAPTER 10: Events in Forests
It's Remarkable That Trees Can Stand Up to Strong Winds
Tree Stems May Break or Uproot
Storms Blow in with a Wide Range of Wind Speeds
Storm Impacts Can Be Severe in Local Areas
Storms that Are Severe Enough to Be Named Are Strong Enough to Topple Vast Numbers of Trees
How Large an Area Can Be Covered by a Single Storm?
How Massive Can a Storm's Impact Be?
When Will the Next Storm Come?
The Next Storm Will Be Different Than the Last One
Trees Provide the Dominant Structure of Forests, But Small Insects Can Play a Very Major Role
How Do Tiny Insects Manage to Kill Large Trees?
Which Trees Are Most Vulnerable to Mountain Pine Beetles?
Which Forests Are Most Susceptible to Mountain Pine Beetles?
Mountain Pine Beetle Impacts Are Consistent When Scaled Up to Regional Areas
Tree Death Alters Environmental Conditions at Local Scales, But Less at Watershed Scales
Why Don't Beetles Kill More Trees?
Is This a Healthy Forest?
Forests Often Thrive When Insects Kill Trees
Should Forests with Lots of Beetle‐Killed Trees Be Logged?
Other Dynamics of Forests and Beetles Occurred Across the Region Too
Other Forests and Other Insects Have Other Stories
Tree Diseases Are Reshaping Forests in a Globalized World
Major Events May, or May Not, Influence the Probability of Other Major Events
Events in Combinations Can Have Drastically Different Legacies
Ecological Afterthought: The Ecology of Avalanches
CHAPTER 11: Events in Forests
Forest Growth Sets the Stage for Rapid Return to Chemical Equilibrium
Thick Bark Protects Cambium from Heat
The Post‐Fire Forest May Be Dominated by Resprouting Vegetation
Post‐Fire Environments Can Be Good for Seedling Establishment
The Spatial Scale of Forest Fires is Important, But Not Simple
Most Forest Fires Are Small, Though the Uncommon Large Fires Have Great Impacts
Fires Burn Differently at Different Places
Periods of Gradual Change Are Punctuated by the Large Changes from Fire Events
Typical Fire‐Free Periods Within Forest Types Vary Across Sites and Over Centuries
When Fire‐Free Intervals Get Longer, Forests Get Denser
The Spatial Aspects of Fires Also Include Patterns Within Burned Patches
Fire Ecology Might, or Might Not, Be Described with Fire Regimes
Fires Change Soils
Fires Generate Erosion in Areas That Burn, with Sediment Deposition Downslope
Erosion After Fire is Usually Not a Problem, But Sometimes It's Very Severe
Each Species of Animal Has a Different Response to Forest Fires
Fires Interact with Other Major Events in Forests
Ecological Afterthoughts: How Do Slow Changes in Forests Shape the Effects of Fires?
CHAPTER 12: Events in Forests
Harvesting Is the Third Largest Forest Event Across the Planet
Few Forests Are Plantations, But Plantations Provide Most of Our Wood
Deforestation Can Be Tallied from Government Reports, or from Satellites
Human Influences on Forests Have a Spectrum from Low to Very High
Tree Farms Are All About Production, Not Broader Ecological Features
How Sustainable Are Tree Farms?
Managed Forests Come in a Variety of Systems
Rotational Forests Have Birthdays
Understories and Overstories Interact Through a Rotation
Continuous Cover Forests Have no Birthdays, and Less Change
Tree Growth Is Faster in Rotational Forestry than in Continuous Cover Forestry
Management of Unmanaged Forests May Seem Like an Oxymoron
How Does Retaining Trees Influence the Next Forest After Logging in Unmanaged Forests?
Harvesting Is the End of the Line for Some Trees and Forests, and the Beginning of the Next Forest
Harvesting Is Not the Only Big Event that Happens in Managed Forests
Can Forests Remove Enough CO
2
from the Atmosphere to Save the Planet?
Ecological Afterthoughts: What's Next for These Forests?
CHAPTER 13: Conservation, Sustainability and Restoration of Forests
Conservation, Sustainability and Restoration Build Values, Ethics, and Esthetics onto a Foundation of Forest Ecology
Conservation, Sustainability and Restoration Are About the Future
Why Do Species Go Extinct, and How Can This Be Prevented?
Conserving Old Forests Is Important, but Old Forests Do Not Last Forever
Conservation and Sustainability Have Similarities
Restoration Comes into Play When Conservation and Sustainability Have Not Been Achieved
The History of a Forest Might Be Read in Reports, in Photographs, in Trees and Remnants of Trees
Clues to the Past Structure of Forests Lurks in Tree Rings, Stumps, and Logs
What Does It Take to Restore a Forest?
Many Forests Have Reestablished Following Agricultural Land Use
Forest Reestablishment May Be Faster with Planting, and Contain More Desirable Species
Forest Reestablishment Leads to the Redevelopment of Forest Soils
Reestablishing Forests in the Absence of Soils Is a Major Challenge, Requiring Insights and Money
Management Can Shift Forests Away from Undesirable Conditions
Two Key Ideas Connect Forest Ecology with Conservation, Sustainability, and Restoration
Ecological Afterthoughts: Restoring Forests May Be About Restoring Non‐Tree Vegetation
CHAPTER 14: Forests of the Future
Forests Have Already Changed, and Continue to Change
Can Invasions Be Predicted?
Some Forests Are More Invasible Than Others
Not all Invasive Species Are Alike: Identity Matters
Plantations of Non‐Native Trees Can Lead to Invasions
Biological Control May Help Limit Invasive Species
Genetics Matter
The Future Is Certain to Be Warmer, with More CO
2
in the Atmosphere
If Droughts Increase, Which Forests and Trees Will Show Increased Mortality?
Changing Climates Will Change the Distribution of Species
Fires Have Always Been Important in Forests, and Fires May Become More Important
People Will Contribute to Shaping Future Forests
All These Factors Will Interact to Shape the Dynamics of Future Forests
Rocket Science Can Get You to the Moon, but Pocket Science Leads to Better Outcomes in Forests
The Core Framework Actually Needs a Fourth Question
Ecological Afterthoughts: Growing Meaning in Forests
References
Index
End User License Agreement
List of Illustrations
Preface
FIGURE A The ecology of all forests can be approached with a core framework ...
FIGURE B Stem growth in tropical forests is higher for sites with higher pre...
FIGURE C The influence of both factors can be examined together by examini...
FIGURE D Rates of wood growth for lodgepole pine forests in Yellowstone Nat...
FIGURE E Sal is a major species across southern Asia, just one species of 7...
Chapter 1
FIGURE 1.1 The Tree. This tulip poplar is a typical tree for temperate fores...
FIGURE 1.2 The daily pattern of incoming sunlight (A) reflects the geometry ...
FIGURE 1.3 Seasonal trends in incoming sunlight (A) lead to almost twofold d...
FIGURE 1.4 Growth of yellow poplar trees is low in drier summers (a negative...
FIGURE 1.5 The dominant tulip poplar tree in the center of this springtime p...
FIGURE 1.6 Although this looks like a topographic map of the Coweeta Basin, ...
FIGURE 1.7 Forest patterns commonly vary with elevation and with local topo...
FIGURE 1.8 Forest composition in the Coweeta Basin in 1935 and in 1990. The ...
FIGURE 1.9 As with the tulip poplar and tulip poplar forest examined in this...
Chapter 2
FIGURE 2.1 The vegetation in the Front Range of the Rocky Mountains in north...
FIGURE 2.2 The distributions of major types of forests can be mapped across ...
FIGURE 2.3 The tallest trees in the world occur in cool, wet locations, and...
FIGURE 2.4 Rates of chemical processes increase with increasing temperature,...
FIGURE 2.5 On an afternoon when air temperature was 25 °C, the temperatures ...
FIGURE 2.6 All objects emit radiation to the environment, and hotter object...
FIGURE 2.7 The total potential sunlight (not accounting for clouds) at 23° l...
FIGURE 2.8 The daily amount of incoming sunlight depends on the aspect of a ...
FIGURE 2.9 The amount of incoming radiation received by a site depends not o...
FIGURE 2.10 The energy budget for a forest clearcut in Oregon, USA on a summ...
FIGURE 2.11 The temperature of the air in the forest in northern Arizona, U...
FIGURE 2.12 Average annual temperatures for sites around the world decline w...
FIGURE 2.13 Air temperature increases with decreasing elevation because incr...
FIGURE 2.14 Daily comparisons of high and low temperatures at locations tha...
FIGURE 2.15 The temperatures of the soil (10 cm below the O horizon) differe...
FIGURE 2.16 Removing some or all of the tree canopy from a high‐elevation fo...
FIGURE 2.17 Buds on spruce trees in northern Sweden burst open and expand ne...
FIGURE 2.18 The average growth of wood in tropical forests around the world ...
FIGURE 2.19 Forests occur in temperate regions where precipitation is typica...
FIGURE 2.20 Severe winds that are not too extreme may topple individual tre...
FIGURE 2.21 What will happen in this forest on a windy day in June? Back in...
FIGURE 2.22 Severe droughts can foster outbreaks of bark beetle populations,...
FIGURE 2.23 The major tree species in the Rocky Mountains, USA can be plott...
Chapter 3
FIGURE 3.1 Millions of years ago, tulip poplars were found across much of wh...
FIGURE 3.2 Some examples of trees from the major conifer families (beginning...
FIGURE 3.3 The view from 30 m up: Tropical rain forests are famous for thei...
FIGURE 3.4 The young fig in Kerala, India in the upper two panels is wrappe...
FIGURE 3.5 Red alder trees form a symbiosis with
Frankia
bacteria, housed i...
FIGURE 3.6 The 50 or so aspen stems visible in this picture are only half of...
FIGURE 3.7 The history of vegetation at a site may be recorded in the form o...
FIGURE 3.8 Ponderosa pine trees were absent from the Rocky Mountains during ...
FIGURE 3.9 Hemlock was a major species of the forests of southern Ontario, ...
FIGURE 3.10 The current animal community in North America bears slight resem...
FIGURE 3.11 Change is the only consistent story of forest ecology for the l...
FIGURE 3.12 Earth is warming, and this warming will be accompanied by chang...
Chapter 4
FIGURE 4.1 The apparent color of leaves changes in the autumn as changing c...
FIGURE 4.2 Rates of transpiration from leaves depends on the density and ope...
FIGURE 4.3 Water flows “down” gradients of potential, from high potentials ...
FIGURE 4.4 The structure of leaves in the canopy of a rain forest in Costa R...
FIGURE 4.5 Eucalyptus plantations in Hawaii also show a clear pattern betwee...
FIGURE 4.6 The photosynthetic capacity of needles (with full sunlight) in a ...
FIGURE 4.7 The tropical location of this eucalyptus plantation in Brazil exp...
FIGURE 4.8 This onyina (or kapok) tree in Ghana has large buttresses which d...
FIGURE 4.9 Fine roots concentrate in the upper soil, including the O horizon...
FIGURE 4.10 The tiny seeds of cottonwoods provide almost no resources to sup...
FIGURE 4.11 Aaltonen (1919) concluded that light alone did not explain the g...
FIGURE 4.12 Douglas‐fir seedlings planted in the understory of a Norway spru...
FIGURE 4.13 Scots pine trees in Finland can withstand temperatures of −50 °...
FIGURE 4.14 Two decades after a forest‐replacing fire, a forest in northern ...
FIGURE 4.15 The survivorship curve (left) for a mountain palm forest in Pu...
FIGURE 4.16 The combination of the addition of new trees and the death of e...
FIGURE 4.17 Many (most?) broadleaved trees can form new tree stems from root...
FIGURE 4.18 Most forest trees originate from seeds produced by trees in the ...
FIGURE 4.19 Beech trees have masting years of high seed production at inter...
FIGURE 4.20 The bark of aspen is white/gray on the surface, with a layer of...
Chapter 5
FIGURE 5.1 Koa forests in Hawaii descended from seeds brought from Australia...
FIGURE 5.2 Beaver‐cutting of aspen stems (top left) typically does not kill ...
FIGURE 5.3 A fivefold increase in ungulate populations (Y axis is scaled to ...
FIGURE 5.4 Domestic livestock are common in many forests, including reindeer...
FIGURE 5.5 The age structure of aspen across the Kaibab Plateau supported th...
FIGURE 5.6 Simple stories could be imagined as useful explanations for popul...
FIGURE 5.7 Map of Isle Royale, where dynamics of populations of moose and wo...
FIGURE 5.8 The dynamics of moose and wolf populations on Isle Royale followe...
FIGURE 5.9 A simulation of forest vegetation in response to intensity of moo...
FIGURE 5.10 Some animal populations fluctuate on a semi‐regular cycle, thoug...
FIGURE 5.11 Populations of snowshoe hares increased with the addition of foo...
FIGURE 5.12 The food web in the “lynx/hare” system in the Yukon includes str...
FIGURE 5.13 Roe deer are medium‐size (20–30 kg) browsing herbivores, with de...
FIGURE 5.14 Over a 30‐year period, the population of elk on the Uncompahgre ...
FIGURE 5.15 Reducing a high population of red deer in the Cairngorm mountai...
FIGURE 5.16 The hypothesis that elk benefit from thermal cover in winter was...
FIGURE 5.17 Fencing can be used to test for the effect of animals in a singl...
FIGURE 5.18 Two canyons in Zion National Park, Utah, US, look very different...
Chapter 6
FIGURE 6.1 Individual trees can find sufficient support, water, and nutrie...
FIGURE 6.2 These profiles come from sites just a few km apart in Brazil. Th...
FIGURE 6.3 Forest growth differs by more than a factor of two across a 10...
FIGURE 6.4 A common‐garden experiment in Toronto, Ontario, Canada found a l...
FIGURE 6.5 A common‐garden experiment in Poland included plots with linden,...
FIGURE 6.6 The diversity of life in soils is almost inconceivable, so here ...
FIGURE 6.7 The water content of the atmosphere varies with latitude (high i...
FIGURE 6.8 Precipitation falls mostly on canopies in forests, and high surfa...
FIGURE 6.9 The growth of trees often increases going down slopes. The two bl...
FIGURE 6.10 Streams flow with water down a valley, but water also moves thr...
FIGURE 6.11 Evapotranspiration can be measured at varying scales in forest...
FIGURE 6.12 The amount of water returned to the atmosphere by forests in A...
FIGURE 6.13 Streamflow increased after clearcutting a watershed in the Cow...
FIGURE 6.14 Streamflow increases when trees are removed, as a result of lo...
FIGURE 6.15 Slash pine trees develop sparse crowns and grow poorly on this ...
FIGURE 6.16 The addition of nitrogen from the atmosphere to forests and oth...
FIGURE 6.17 The forms, transformations, and movement of N in forests are co...
FIGURE 6.18 The log in the upper left decomposed over about a century, and ...
FIGURE 6.19 The annual flow of streamwater increases across watersheds of ...
Chapter 7
FIGURE 7.1 The biomass of old growth forests differs among forest types ar...
FIGURE 7.2 During the summer, total photosynthesis is quite high for a 60‐y...
FIGURE 7.3 The mass of a eucalyptus tree was estimated by cutting down the ...
FIGURE 7.4 Classic forestry approaches determined the general trend of volum...
FIGURE 7.5 The production of forests across a watershed in Idaho, USA (Figur...
FIGURE 7.6 The production ecology of individual trees can be used to unders...
FIGURE 7.7 The growth of forests increases (or plateaus) with increasing den...
FIGURE 7.8 The growth of an unthinned forest of tulip poplar (on a site whe...
FIGURE 7.9 A long‐term experimental plot near the coast of Oregon tracked th...
FIGURE 7.10 Growth of a focal tree (circled in red in the left picture) may ...
FIGURE 7.11 The size and distance of nearby N‐fixing falcataria trees infl...
FIGURE 7.12 A mixed plantation of falcataria and eucalyptus grew 40% more a...
FIGURE 7.13 An analysis of 5000 inventory plots in German forests showed no ...
FIGURE 7.14 Experiments on mixed‐species forests compare the growth in mono...
FIGURE 7.15 The effects of mixture changes over time, as shown in this expe...
FIGURE 7.16 A common garden experiment in Poland included replicated plots o...
FIGURE 7.17 Forests in Ontario, Canada were sampled for understory biomass i...
FIGURE 7.18 The 50‐year changes in a forest in coastal Oregon (same forest a...
FIGURE 7.19 The number of trees of various sizes did not change much in an ...
FIGURE 7.20 Forests may accumulate decaying woody material for decades or ce...
FIGURE 7.21 At the end of a century‐long rotation, a Norway spruce forest i...
Chapter 8
FIGURE 8.1 The spatial dimensions of forests include the land area beneath t...
FIGURE 8.2 The minimal size of a forest might be the domain of a single tre...
FIGURE 8.3 The delineation of an operationally useful unit, a strand, is cle...
FIGURE 8.4 A scale of 1 ha (0.01 km
2
, upper left) typically includes dozens...
FIGURE 8.5 The number of plant species found in a forest dominated by aspen ...
FIGURE 8.6 Grazing impacts have been studied in thousands of experiments wh...
FIGURE 8.7 Elk allocate time across landscapes in the summer in Rocky Mounta...
FIGURE 8.8 The species composition of plots in an evergreen, broadleaved for...
FIGURE 8.9 The basal area (and biomass) of a three‐century‐old forest in Ma...
FIGURE 8.10 A 90 000‐ha landscape in Sequoia National Park in California, US...
FIGURE 8.11 A broadleaved forest in Japan showed increasing stem biomass an...
FIGURE 8.12 Transpiration varies from less than 200 mm yr
−1
at low el...
FIGURE 8.13 The pattern of gaps across the Cedar Creek watershed in western...
FIGURE 8.14 Most of the ground area beneath tropical forests receives only a...
FIGURE 8.15 The edge effect of a clearcut adjacent to an intact forest depe...
FIGURE 8.16 An outbreak of spruce budworms created dead patches and edges i...
FIGURE 8.17 A map of a hectare of a Scots pine forest in Finland, showing cl...
FIGURE 8.18 An old growth forest in western Washington, USA averaged almost ...
FIGURE 8.19 The species, diameter, and location of all stems were mapped in ...
FIGURE 8.20 The map of species, sizes, and locations can lead to other map...
FIGURE 8.21 Statistical analyses can examine how clumped, random, or unifor...
FIGURE 8.22 Riparian forests differ from upland ecosystems in dry regions, w...
FIGURE 8.23 A large gradient in soils from upland to riparian locations in F...
FIGURE 8.24 Clonal plantations of eucalyptus are some of the most uniform f...
FIGURE 8.25 The probable risk of exotic plant encroachment was estimated ac...
FIGURE 8.26 The pieces of the puzzle include thick‐barked old trees that su...
Chapter 9
FIGURE 9.1 A classic story of forest change in the Rocky Mountains begins wi...
FIGURE 9.2 The ponderosa pine forests in the Fort Valley Experimental Forest...
FIGURE 9.3 After 20 years with no grazing, the impact of heavy grazing by li...
FIGURE 9.4 Henry Thoreau measured the width of the first 50 years of growth...
FIGURE 9.5 Tree rings contain information that can be extracted with dendro...
FIGURE 9.6 Tree rings reveal the impact of an outbreak of the fungal pathoge...
FIGURE 9.7 Sixty to eighty trees of each of three species were cored in a 20...
FIGURE 9.8 The annual growth of eight giant sequoias was determined based o...
FIGURE 9.9 Photos from Cooper's research plots in Glacier Bay, Alaska, USA. ...
FIGURE 9.10 Benches are created on river floodplains, and newly deposited se...
FIGURE 9.11 The trend in tree growth for lodgepole pine forests in Yellowst...
FIGURE 9.12 The growth of young forests increases as roots and leaves increa...
FIGURE 9.13 Stem production of a eucalyptus plantation in Hawaii, USA declin...
FIGURE 9.14 Growth of forests across Sweden increased consistently by about ...
FIGURE 9.15 A total of 250 years of change are illustrated in these diorama ...
FIGURE 9.16 Deforestation removed two‐thirds of Massachusetts' forests withi...
FIGURE 9.17 Land use in the Belgian Ardennes changed the forests in major wa...
FIGURE 9.18 The growth of an individual tree is constrained by unavoidable, ...
FIGURE 9.19 The vegetation in a 73 km
2
watershed in Yellowstone National Pa...
Chapter 10
FIGURE 10.1 Insects (and other arthropods) comprise a large part of the spec...
FIGURE 10.2 The risk of wind damage to trees and forests can be examined in...
FIGURE 10.3 Severe winds break the stems of well‐rooted trees (left, lodgepo...
FIGURE 10.4 Hurricane Hugo blew across Puerto Rico as a Category 4 storm (w...
FIGURE 10.5 A tornado in Massachusetts, USA in 2011 toppled most of the lar...
FIGURE 10.6 The storm Lothar had winds as high as 50 m s
−1
(200 km hr
FIGURE 10.7 An analysis of over 200 forest inventory plots documented the ec...
FIGURE 10.8 Hurricane Maria stormed across Puerto Rico in 2017, dropping 10...
FIGURE 10.9 Airborne lidar images of Puerto Rico forests before (upper) an...
FIGURE 10.10 Most of the non‐harvest mortality of forests across Europe res...
FIGURE 10.11 Hurricanes occur frequently on and near Jamaica, but the storm...
FIGURE 10.12 The photo on the left (10 x 10 km) shows a 150‐year...
FIGURE 10.13 Bark beetles harm trees primarily by interrupting water flow f...
FIGURE 10.14 Larger trees may be more susceptible, or less susceptible, to bark...
FIGURE 10.15 A four‐decade experiment examined the effects of repeated thin...
FIGURE 10.16 Across the Rocky Mountains in the USA, tree deaths from mountain...
FIGURE 10.17 Twenty‐five watersheds across the Rocky Mountains in the USA had...
FIGURE 10.18 This picture of the “red hand of death” comes from...
FIGURE 10.19 A set of 20 forests in southeastern Wyoming, USA were dominat...
FIGURE 10.20 Treatments were applied across 12 sites where dominant lodgepol...
FIGURE 10.21 Across the western USA, several species of bark beetles showed...
FIGURE 10.22 Old‐growth forests of spruce and fir, and of lodgepole pine, e...
FIGURE 10.23 Avalanches are major events in some mountainous areas. An aval...
Chapter 11
FIGURE 11.1 Cork oak in Portugal is a prime example of a fire‐adapted tree w...
FIGURE 11.2 The thick bark of large ponderosa pine trees protects the growin...
FIGURE 11.3 Indexes of risks from fire can be created by combining multiple...
FIGURE 11.4 Some trees sprout new branches and leaves from buds in the camb...
FIGURE 11.5 Many species resprout from surviving root systems or bases of ...
FIGURE 11.6 A forest of lodgepole pine on a glacial moraine in Colorado, USA...
FIGURE 11.7 A few years after a crown fire, the density of seedlings declin...
FIGURE 11.8 A 2000‐ha fire in a spruce/fir forest in New Mexico, USA had pat...
FIGURE 11.9 Most fires in Brazil are small, and few are very large. The two...
FIGURE 11.10 Fires do not occur everywhere, all the time, or with the same i...
FIGURE 11.11 Management of longleaf pine plots at the Tall Timbers Research...
FIGURE 11.12 Fires may kill the cambium on part of a tree stem, leading to t...
FIGURE 11.13 Fires return to ponderosa pine forests in northern Colorado wi...
FIGURE 11.14 With a fire‐free period of over a century, the canopy of ponde...
FIGURE 11.15 This hillside burned about a century ago, with many trees survi...
FIGURE 11.16 Locations of trees and their ages allow partial reconstruction...
FIGURE 11.17 Confidence in maps of fire regimes would be warranted if a simp...
FIGURE 11.18 Nitrogen contained in organic matter burns just like the carbon...
FIGURE 11.19 Fire impacts on soil include raising soil temperatures. The tr...
FIGURE 11.20 Soils can have patches that repel water rather than absorb it,...
FIGURE 11.21 Post‐fire erosion is usually minor, but in the less common situ...
FIGURE 11.22 A severe forest fire in Warrumbungle National Park in New Sout...
FIGURE 11.23 Many species thrive in the aftermath of fires, including beetl...
FIGURE 11.24 A ponderosa pine forest in the Spring Mountains, Nevada, USA, ...
Chapter 12
FIGURE 12.1 Archeological relocation of ancient Roman settlements showed le...
FIGURE 12.2 Almost all forests fall into the category of unplanted, unmanag...
FIGURE 12.3 Forests around the world have a wide range of costs and values, ...
FIGURE 12.4 A spectrum of management intensity leads to very different fore...
FIGURE 12.5 Intensively managed tree farms, such as clonal eucalyptus planta...
FIGURE 12.6 The productivity of acacia more than doubled across four rotatio...
FIGURE 12.7 Growth rates of eucalyptus across a large area of southern Brazi...
FIGURE 12.8 The harvest that precedes a rotation can have a legacy on growth...
FIGURE 12.9 Understory vegetation is typically very important in managed ro...
FIGURE 12.10 Continuous cover forestry entails harvesting of single trees, o...
FIGURE 12.11 A computer visualization of a continuous‐cover forest, viewed ...
FIGURE 12.12 Forests that developed without direct management may have very ...
FIGURE 12.13 After clearcutting of an old‐growth forest in Oregon, USA, the...
FIGURE 12.14 Experiments in variable retention silviculture on Vancouver Isl...
FIGURE 12.15 Understory responses to variable retention treatments in the MA...
FIGURE 12.16 Variable retention treatments across four sitesshowed stro...
FIGURE 12.17 Harvesting 50‐year‐old managed forests of Douglas‐fir in the no...
FIGURE 12.18 Most logging is done by machines that cut trees, and sometimes ...
FIGURE 12.19 The risks from wind generally increase after forest harvesting ...
FIGURE 12.20 Severe fires in 1939 burned unmanaged forests across New South...
FIGURE 12.21 Rates of harvest increased in Sweden in the past 25 years, lead...
FIGURE 12.22 The unmanaged forest on the left has trees of a variety of age...
Chapter 13
FIGURE 13.1 A panoramic photo set was taken from a sycamore tree in 1939, l...
FIGURE 13.2 90% or more of known extinctions of mammals and birds resulted f...
FIGURE 13.3 These western hemlock and Douglas‐fir trees are over 400 years ...
FIGURE 13.4 The population of elk was held low in the mid‐1900s through hunt...
FIGURE 13.5 A lithograph was made of the view from Mount Trumbull in Arizona...
FIGURE 13.6 A century of change in the San Juan Mountains of Colorado, USA, ...
FIGURE 13.7 The historical forest composition and structure in northern Wisc...
FIGURE 13.8 Historical composition and structure can be examined based on c...
FIGURE 13.9 A broadleaved forest in New Hampshire, USA had all trees cut an...
FIGURE 13.10 A young reestablished forest was cleared at this site near Pem...
FIGURE 13.11 An experiment that mixed 20 native species (fast‐growing, slow‐...
FIGURE 13.12 The cost of reestablishing native tree species might be reduce...
FIGURE 13.13 These soils are 25 m apart in the Duke Forest in North Carolina...
FIGURE 13.14 A greenhouse experiment demonstrated that acacia seedlings bar...
FIGURE 13.15 A large fire in Arizona, USA (Rodeo‐Chediski) burned more sever...
FIGURE 13.16 A 50‐year‐old plantation of Douglas‐fir (with some western hem...
FIGURE 13.17 A restoration treatment of this ponderosa pine forest in northe...
Chapter 14
FIGURE 14.1 The forests of the eastern United States since 1980 experienced...
FIGURE 14.2 Across North America, annual mortality rates increased from nea...
FIGURE 14.3 Henry David Thoreau recorded the timing of flower blooming and ...
FIGURE 14.4 A MAXENT analysis of sites in Rocky Mountain National Park, USA...
FIGURE 14.5 Regions of the USA have up to several hundred invasive (non‐na...
FIGURE 14.6 Forests in Rocky Mountain National Park, USA with high cover of...
FIGURE 14.7 The falcataria trees in the upper picture were more than 40 m t...
FIGURE 14.8 The pictures show the invasion of lodgepole pine (from North A...
FIGURE 14.9 Before the introduction of parasitoid flies, invasive winter mo...
FIGURE 14.10 The importance of provenance (the geographic location of seed ...
FIGURE 14.11 The patterns of
13
C isotopes in tree rings from over 400 fores...
FIGURE 14.12 A strong, three‐year drought in the Coweeta forest led to wides...
FIGURE 14.13 A much greater percentage of small tulip poplar trees died fro...
FIGURE 14.14 Mortality was higher for taller trees with drought in Califor...
FIGURE 14.15 The extent of forest fires in the USA more than doubled after ...
FIGURE 14.16 A shift to a warmer, drier climate with more frequent drought...
FIGURE 14.17 A random exercise illustrates how shortening the period betwe...
FIGURE 14.18 An aspen/conifer forest was harvested to promote development o...
FIGURE 14.19 The core framework that applies to all forests, across space ...
FIGURE 14.20 What insights, meanings, and beauty will you quilt together f...
Guide
Cover Page
Title Page
Copyright Page
Dedication Page
Preface
Acknowledgements
Table of Contents
Begin Reading
References
Index
Wiley End User License Agreement
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Forest Ecology
An Evidence‐Based Approach
DAN BINKLEY
School of Forestry, Northern Arizona University
This edition first published 2021© 2021 John Wiley & Sons Ltd
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Library of Congress Cataloging‐in‐Publication Data
Names: Binkley, Dan, author. | John Wiley & Sons, publisher.Title: Forest ecology : an evidence‐based approach / Dan Binkley, School of Forestry, Northern Arizona University.Description: First edition. | Hoboken, NJ : Wiley‐Blackwell, 2021. | Includes index.Identifiers: LCCN 2021001373 (print) | LCCN 2021001374 (ebook) | ISBN 9781119703204 (paperback) | ISBN 9781119704409 (adobe pdf) | ISBN 9781119704416 (epub)Subjects: LCSH: Forest ecology.Classification: LCC QH541.5.F6 B555 2021 (print) | LCC QH541.5.F6 (ebook) | DDC 577.3–dc23LC record available at https://lccn.loc.gov/2021001373LC ebook record available at https://lccn.loc.gov/2021001374
Cover Design: WileyCover Image: © Dan Binkley
The development of forests always includes contingent events: if an event happens, such as a fire, windstorm, or insect outbreak, the future of the forest will unfold differently than if the event did not happen (or if it happened in some other way at another time). This book would not be in front of you without the contingent event of Wally showing up as a young professor when I was an undergraduate at the School of Forestry at Northern Arizona University. Wally's engaging curiosity, interest in students, and active research program pulled my interests and future path into the domain of forest ecology. He continued to be a mentor through my grad student days at other universities, and most recently he led us through establishing the Colorado Forest Restoration Institute (modeled on NAU's Ecological Restoration Institute). It's been a good path.Thanks Wally.
Dan BinkleyFort Collins, Colorado
Preface
How Do We Come to Understand Forests?
This book supports learning about forest ecology. A good place to start is with a few points about knowledge, followed by a framework on how to approach forest ecology, some key features of using graphs to interpret information, and finally coming around to how to think about questions and answers in forests.
Humans try to understand complex worlds through a range of perspectives. Art tries to capture some essential features of a complex world, emphasizing how parts interact to form wholes. Religions explain how worlds work now, how the worlds came to be, and what will come next. Both art and religion develop from ideas and concepts, originated by individual artists or passed down by religious societies. How do we know if a work of art or an idea in religion represents the real world accurately? This question generally isn’t important. Art that satisfies the artist is good art, and religions are accepted on faith.
Art and religion have been evolving for more than 100 000 years, and lands and forests have been part of that development. One of the first written stories is a religious one from the Epic of Gilgamesh, from more than 4000 years ago from the Mesopotamian city of Uruk (now within Iraq). Gilgamesh and a companion traveled to the distant, sacred Cedar Mountain to cut trees. Lines from the epic poem include (based on Al‐Rawi and George 2014):
They stood there marveling at the forest, observing the height of the cedars … They were gazing at the Cedar Mountain, dwelling of gods, sweet was its shade, full of delight. All tangled was the thorny undergrowth, the forest a thick canopy, cedars so entangled it had no ways in. For one league on all sides cedars sent forth saplings, cypresses for two‐thirds of a league. Through all the forest a bird began to sing … answering one another, a constant din was the noise. A solitary tree‐cricket set off a noisy chorus. A wood pigeon was moaning, a turtle dove calling in answer. At the call of the stork, the forest exults. At the cry of the francolin bird, the forest exults in plenty. Monkey mothers sing aloud, a youngster monkey shrieks like a band of musicians and drummers, daily they bash out a rhythm …
And after slaying the demigod who protected the forest, Gilgamesh's companion laments:
My friend, we have cut down a lofty cedar, whose top abutted the heavens … We have reduced the forest to a wasteland.
What would actually happen if cedar trees were cut on a mountain? Would more cedar trees establish, would the post‐cutting landscape provide suitable habitat for the birds and monkeys? Would floods result? Anything could happen next in a story, but understanding which stories about the real world warrant confidence depends on the strength of evidence.
The core of understanding is knowing how one thing connects to another, and if the connections are the same everywhere and all the time, or if local details strongly influence the connections. The seasonal movements of the sun across the sky are consistent across years, but appear to differ from southern to northern locations. Multiple stories might explain the Sun's march with reasonable accuracy. Patterns etched on rocks by ancient artists may line up with key points in the Sun's seasonal patterns, and the movements of the Sun may reliably follow ceremonies convened by a society with the goal of ensuring the Sun's path. With art and religion, people may have understood the movement of the sun through the year was actually caused by the etchings on rocks or by ceremonial rites. These ideas may or may not have been true, but stories do not have to be true to be useful. Stories can persist as long as they are not so harmful that a society would be undermined. This idea is the same as genes in a population; natural selection does not aim toward retaining the best genes across generations, it only tends to remove genes that are harmful.
The human drive to understand cause and effect entered a new dimension when the notion developed of trying to figure out if an appealing idea might be wrong. Ideas of Newtonian physics and especially relativistic physics not only chart the apparent movement of the sun with more precision than would be possible from rock etchings or ceremonies, they also would be very, very easy to prove to be wrong. A deviation as small as one part in one million could prove the expectations of physicists were wrong. This innovation of science, based on investigating if an idea is wrong, developed very slowly alongside art and religion, and then exploded over the past four centuries to change the world.
Scientific thinking comes with two parts: creative new ideas about how the world works, and tough challenges that find out if the idea warrants confidence. Clearly most of the creative new ideas that scientists developed were wrong, either fundamentally or just around the edges. The ideas that withstood the challenges of testing have transformed the planet, feeding billions more people than our historical planet could have fed, sending machines across the solar system, and giving us an understanding of how our atoms formed in a collapsing star and how those same stellar reactions can be harnessed to obliterate cities. The idea that investigating whether an idea might be wrong has proven to be the most powerful insight humans have ever developed.
Returning to forests, trees and forests continue to be parts of art, religion, and science. When it comes to the scientific understanding of forests, both parts of science are needed: the generation of creative ideas and the challenging of those ideas to see if they warrant confidence. How do creative ideas about forests arise? That complex question has no simple answer, though creative ideas might arouse observation, learning, thinking, and pondering. The second part is more straightforward; once an idea is expressed, the hard work can begin on challenging the idea, to see if it's a better idea for accounting how forests differ across space and time.
A key point in science is being clear on which of these two aspects is being developed. The generation of a creative idea should not be mistaken for a reliable, challenge‐based conclusion. Challenging an existing idea is important, though real gains in insights might depend on new ideas and new methods of measuring and interpreting.
How Confident Should You Be?
The confidence warranted in the truth of art or religion does not depend on the strength of evidence. The confidence warranted in scientific ideas always depends on evidence. Some scientific ideas warrant more confidence than others, and a scale of increasing confidence would be:
Weakest: Ideas based on appealing thoughts or concepts;
Weak: Analogies where well‐tested insights from another area of knowledge are extended to a new area;
Moderately strong: Ideas supported by good evidence from one or a few case studies or experiments; and
Strong: Evidence‐based ideas with robust trends across many locations and periods of time.
This is also a scale representing how surprising it would be to find out an idea was wrong, with the level of surprise increasing down the list. These distinctions may seem a bit dull and uninteresting, but the differences are as important as a person trying to fly on a magic carpet, to fly like a bird, to fly in an experimental airplane, or to fly in airplane certified to be safe with a record of thousands of hours of safe flights. Which approach to flying warrants the highest confidence for arriving safely at a distant destination?
One of the most common sources of creative ideas is making analogies. This tree has fruits that look like acorns, just like oaks have acorns, so this tree belongs with the group of oak species. Another analogy would be that aspen trees regenerate across burned hillsides and so do lodgepole pine trees, so aspen belongs in the group that lodgepole pine belongs in. Analogies may be true or false, but the key is to recognize that analogies represent only an initial, incomplete step of science. An analogy is reliably useful only when challenged by evidence. The acorn example could be challenged in many ways, including comparing other features of the tree with other oak trees, or especially by comparing DNA and genes. The analogy between the aspen and pine is not so obviously useful. If a grouping included trees that do well after severe fires, the trees indeed share useful features. For any other grouping, such as a suitability to feed beavers or mountain pine beetles, they clearly do not.
Creative ideas may begin as concepts or analogies, but gauging confidence depends on taking the next step to list the similarities and differences between the objects or sets of objects. An analogy might have more potential for useful insights when the similarities include major, diverse features. Analogies are less useful (or even harmful) when the list of key differences is substantial (Neustadt and May 1986).
All Forest Ecology Fits Into a Framework and a Method
Whether a creative idea originated in a concept, an analogy or another line of reasoning, science is incomplete if the idea is not challenged by evidence. The challenge needs to include ways that have a chance to show the idea to be wrong. This book raises questions about how forests work, and examines how the ideas have been challenged by evidence.
A good step for thinking about complex systems is developing a framework for understanding pieces of the system, and how the pieces interact. This book uses a core framework that can be used in every forest at all times (Figure A).
FIGURE A The ecology of all forests can be approached with a core framework and a core method, each asking three questions. The questions apply very generally, while the answers always depend on local details.
The core framework is structured by three simple questions. “What's up with this forest?” leads to familiar methods of measurement. “How did the forest get that way?” can be investigated with a variety of approaches for finding and interpreting historical evidence. “What's comes next?” usually can have only fuzzy answers because the future is not yet written for forests.
This set of core framework questions leads to a second trio of method‐related questions that develop the necessary details to answer the core questions.
What is the central tendency (or mean) for this set of objects? (The set could be trees in this forest, forests across this landscape, or the forests at this location across millennia.)
How much variation occurs around that central tendency? (Do all trees increase in growth rate across all ages, or do some decline?)
What factors help explain when cases fall above (or below) the central tendency? (Are suppressed trees likely to decline in growth rate while large trees continue to increase?)
The core framework and core method may seem a bit awkward or unclear, but they should become clearer (and more useful) as the book uses them to investigate how forests work.
