Climate Change Linked to Major Vegetation Shifts Worldwide （转载） In a paper published June 7 in the journal Global Ecology and Biogeography, researchers present evidence that over the past century, vegetation has been gradually moving toward the poles and up mountain slopes, where temperatures are cooler, as well as toward the equator, where rainfall is greater. Moreover, an estimated one-tenth to one-half of the land mass on Earth will be highly vulnerable to climate-related vegetation shifts by the end of this century, depending upon how effectively humans are able to curb greenhouse gas emissions, according to the study. The results came from a meta-analysis of hundreds of field studies and a spatial analysis of observed 20th century climate and projected 21st century vegetation. The meta-analysis identified field studies that examined long-term vegetation shifts in which climate, rather than impacts from local human activity such as deforestation, was the dominant influence. The researchers found 15 cases of biome shifts since the 18th century that are attributable to changes in temperature and precipitation. "This is the first global view of observed biome shifts due to climate change," said the study's lead author Patrick Gonzalez, a visiting scholar at the Center for Forestry at UC Berkeley's College of Natural Resources. "It's not just a case of one or two plant species moving to another area. To change the biome of an ecosystem, a whole suite of plants must change." The researchers calculated that from 1901 to 2002, mean temperatures significantly increased on 76 percent of global land, with the greatest warming in boreal, or subarctic, regions. The most substantial biome shifts occurred where temperature or precipitation changed by one-half to two standard deviations from 20th century mean values. Some examples of biome shifts that occurred include woodlands giving way to grasslands in the African Sahel, and shrublands encroaching onto tundra in the Arctic. "The dieback of trees and shrubs in the Sahel leaves less wood for houses and cooking, while the contraction of Arctic tundra reduces habitat for caribou and other wildlife," said Gonzalez, who has served as a lead author on reports of the Intergovernmental Panel on Climate Change (IPCC). "Globally, vegetation shifts are disrupting ecosystems, reducing habitat for endangered species, and altering the forests that supply water and other services to many people." To identify the areas most vulnerable to future vegetation shifts, the researchers combined statistical analyses of observed climate data from the 20th century with models of vegetation change in the 21st century. Based upon nine different combinations of IPCC greenhouse gas emissions scenarios and climate models, the researchers divided the world's land into five classes -- from very high to very low -- of vulnerability to biome shifts. "Scientists had not quantified this risk before," said Gonzalez. "We developed a simple classification system that natural resource management agencies can use to identify regions in greatest need of attention and planning. We have worked with the U.S.D.A. Forest Service and the U.S. Fish and Wildlife Service to explore the application of our results to adaptation of natural resource management." Gonzalez said that because of limited resources, it may be prudent to focus on protecting areas of greater resilience to ecological changes so that they can serve as refuges for plants and animals. "It is also useful to identify places of higher vulnerability, because agencies will need to consider adaptation measures for vulnerable ecosystems," he said. "Some shifts in vegetation could increase fuel for wildfires, for example, so prescribed burning may be necessary to reduce the risk of catastrophic fires." "Approximately one billion people now live in areas that are highly to very highly vulnerable to future vegetation shifts," said Gonzalez. "Ecosystems provide important services to people, so we must reduce the emissions that cause climate change, then adapt to major changes that might occur."
题目 Nutrient Cycling and Limitation: Hawai'i as a Model System 作者 Peter M. Vitousek 获奖 Winner of the 2005 Marsh Ecology Book of the Year Award, British Ecological Society 出版信息 Paper | 2004 | $52.00 / 35.95 232 pp. | 6 x 9 | 10 halftones. 84 line illus. 18 tables. 介绍 The availability or lack of nutrients shapes ecosystems in fundamental ways. From forest productivity to soil fertility, from the diversity of animals to the composition of microbial communities, nutrient cycling and limitation are the basic mechanisms underlying ecosystem ecology. In this book, Peter Vitousek builds on over twenty years of research in Hawai'i to evaluate the controls and consequences of variation in nutrient availability and limitation. Integrating research from geochemistry, pedology, atmospheric chemistry, ecophysiology, and ecology, Vitousek addresses fundamental questions: How do the cycles of different elements interact? How do biological processes operating in minutes or hours interact with geochemical processes operating over millions of years? How does biological diversity interact with nutrient cycling and limitation in ecosystems? The Hawaiian Islands provide the author with an excellent model system for answering these questions as he integrates across levels of biological organization. He evaluates the connections between plant nutrient use efficiency, nutrient cycling and limitation within ecosystems, and nutrient input-output budgets of ecosystems. This book makes use of the Hawaiian ecosystems to explore the mechanisms that shape productivity and diversity in ecosystems throughout the world. It will be essential reading for all ecologists and environmental scientists. Reviews: work began by understanding the interactive controls over nutrient limitation after forest disturbance. In Nutrient Cycling and Limitation , Vitousek explores this theme on a grand canvas, basing it on his own work and that of a small army of students and collaborators. . . . This book will reward reading and re-reading, and is an excellent introduction to biogeochemical ecology for those coming from other fields of science.--David Schimel, Nature One of the most impressive aspects of Nutrient Cycling and Limitatio is the scope of the material it covers, and the extent to which the material is integrated to provide a truly ecosystem-level overview, that is itself placed neatly within a global context. . . . he book provides a wide-ranging and authoritative coverage of a crucial topic.--Graeme Hastwell, Austral Ecology Peter Vitousek's Nutrient Cycling and Limitation makes an important contribution to the field of biogeochemistry. . . . excellent book. . . . Nutrient Cycling and Limitation is essential reading for students and scientists interested in terrestrial biogeochemistry. It is a model of good science writing and a crisp and clear introduction to some of the big ideas that intrigue ecosystem ecologists.--Jerry Melillo, Bioscience Endorsement: Peter Vitousek is tied closely to the 'aina--the land--of Hawaii, both by birth and by the successful scientific career he has nurtured over the past two decades. His personal, and sometimes passionate, presentation sweeps across habitats, across phyla and across disciplines. It is an authoritative account of his research and his vision.--David M. Karl, University of Hawaii 图书内容 TABLE OF CONTENTS: List of Tables xi List of Figures xiii Preface xix Chapter One: Introduction 1 Chapter Two: The Hawaiian Islands as a Model Ecosystem 6 Model Systems 6 Microcosms and Well-studied Systems 8 A Brief Natural History 9 The Formation of the Hawaiian Islands 9 Determinants of Climate 15 Isolation 19 Evolution, Conservation, and Culture 20 Evolution and Speciation 20 Conservation Biology 22 Cultural Evolution 22 Chapter Three: Gradients in Environmental Factors, Gradients in Ecosystems 24 The State Factor Framework 24 Environmental Gradients as Model Systems 26 Temperature 27 Precipitation 29 The Mauna Loa Matrix 30 A Substrate Age Gradient across the Hawaiian Islands 31 Age Control 35 Climate History 35 Basic Features of the Gradient 39 Chapter Four: Patterns and Processes in Long-term Ecosystem Development 42 A Theory for Nutrient Dynamics during Ecosystem Development 42 Biogeochemical Processes on the Substrate Age Gradient 45 Soil P Pools 45 C and N Pools 45 Available Nutrients 46 Foliar Nutrients 49 Forest Productivity 51 Efficiencies of Resource Use 53 Decomposition and Nutrient Regeneration 59 Soil Organic Matter Turnover 66 Plant-Soil-Microbial Feedbacks 66 Chapter Five: Experimental Studies of Nutrient Limitation and the Regulation of Nutrient Cycling 70 Fertilization Experiments 71 Nutrient Limitation 74 Nutrient Availability and Plant-Soil-Microbial Feedback 78 Tissue Nutrient Concentrations 78 Productivity 78 Resource Efficiencies 79 Decomposition 84 Nutrient Regeneration 87 Controls of Plant-Soil-Microbial Feedback 87 Chapter Six: Nutrient Inputs to Hawaiian Ecosystems: Pathways, Rates, and Controls 92 Inputs of Elements 92 Weathering 93 Concepts and Definitions 93 Approaches 94 Element Inputs via Weathering 97 Atmospheric Inputs 98 Background 98 Deposition Measurements 100 Inputs of Water 101 Nitrogen Inputs 101 Influence of an Active Volcano 102 Inputs of Other Elements 103 Long-Distance Dust Transport 105 Background 105 Methods 105 Element Inputs 106 The Fate of Dust 107 Biological N Fixation 109 Background 109 Approach 109 Rates of Fixation 110 Other Inputs 110 Combined Inputs by All Known Pathways 111 Strontium Isotopes: A Direct Test of Input Pathways 112 Chloride and Sulfate 114 Mobile Cations 114 Silicon and Aluminum 116 Nitrogen and Phosphorus 117 Chapter Seven: Nutrient Outputs: Pathways, Controls, and Input-Output Budgets 121 Output Pathways 122 Leaching 122 N-Containing Trace Gases 124 Erosion 126 Other Pathways of Loss 126 Rates and Controls of N and P Losses 128 Input-Output Budgets 133 Budget Calculations 134 Using These Element Budgets 142 Chapter Eight: Issues and Opportunities 143 Interactions of Time Scales 143 An Exploratory Model 143 Supply versus Demand 144 Plant-Soil-Microbial Feedbacks 146 Sources and Sinks 148 Inputs and Outputs 150 Interactions across Scales 152 The Regulation of Nutrient Inputs and Outputs 154 Demand-Independent Pathways of Element Loss 155 Implications of Demand-Independent Nutrient Losses 159 Stoichiometry and Flexibility 160 Within-System Element Cycling 162 Inputs and Outputs 169 Biological N Fixation 173 Differences in Populations, Species, and Diversity 177 Biological Differences and Ecosystem Functioning 177 Diversity and Ecosystem Functioning 184 Three Final Points 188 References 191 Index 219
题目 Ecological Stoichiometry: The Biology of Elements from Molecules to the Biosphere 作者 Robert W. Sterner James J. Elser With a foreword by Peter Vitousek 出版年代 Paper | 2002 | $60.00 / 41.95 584 pp. | 6 x 9 | 21 tables. 92 line illus. 4 halftones. 介绍 All life is chemical. That fact underpins the developing field of ecological stoichiometry, the study of the balance of chemical elements in ecological interactions. This long-awaited book brings this field into its own as a unifying force in ecology and evolution. Synthesizing a wide range of knowledge, Robert Sterner and Jim Elser show how an understanding of the biochemical deployment of elements in organisms from microbes to metazoa provides the key to making sense of both aquatic and terrestrial ecosystems. After summarizing the chemistry of elements and their relative abundance in Earth's environment, the authors proceed along a line of increasing complexity and scale from molecules to cells, individuals, populations, communities, and ecosystems. The book examines fundamental chemical constraints on ecological phenomena such as competition, herbivory, symbiosis, energy flow in food webs, and organic matter sequestration. In accessible prose and with clear mathematical models, the authors show how ecological stoichiometry can illuminate diverse fields of study, from metabolism to global change. Set to be a classic in the field, Ecological Stoichiometry is an indispensable resource for researchers, instructors, and students of ecology, evolution, physiology, and biogeochemistry. From the foreword by Peter Vitousek: his book represents a significant milestone in the history of ecology. . . . Love it or argue with it--and I do both--most ecologists will be influenced by the framework developed in this book. . . . There are points to question here, and many more to test . . . And if we are both lucky and good, this questioning and testing will advance our field beyond the level achieved in this book. I can't wait to get on with it. Reviews: Few, if any, details of stoichiometry seem to have been overlooked by Sterner and Elser, and their book will be a useful reference to me for many years to come. . . . The hundreds of references in the bibliography are worth the price of the book alone.--David W. Schindler, Nature Robert Sterner and James Elser take a giant stride in knitting together perspectives across scales, biomes, and disciplines to craft an integrative and predictive vision of the topic. . . . It knits together such a broad range of relevant topics that anyone interested in the connections between biology and elemental cycles should give it a try.--Anthony F. Michaels, Science I believe that his is one of the most important books written in ecology in the last 10 years. . . . I predict that in a few years it will be inconceivable to ignore the stoichiometric perspective when tackling an ecological problem. . . . Ecological Stoichiometry is well written in colloquial and friendly prose. The authors strived to explain their arguments clearly and in detail. The many mathematical models are explained with laudable lucidity and the figures that illustrate them are consistently good.--Carlos Martinez Del Rio, Ecology How often do you read a book that has a large number of 'aha!' moments in every chapter? This is a significant piece of synthesis and scholarship that brings together a very large number of disciplines and disparate chunks of data into a very satisfying whole. . . . Never before have I seen a book which spans the scales from molecular biology to ecosystems so effectively. . . . It is sure to become a classic.--Graham Harris, Journal of Plankton Research 图书内容 TABLE OF CONTENTS: List of Figures ix List of Tables xiii Foreword xv Preface xvii 1. Stoichiometry and Homeostasis 1 Scope 3 Stoichiometry and Homeostasis 8 Yield 25 The Redfield Ratio 27 Conventions and Concerns about Element Ratios 31 Some Conventions about Growth Rate 34 A Logical Framework 35 The Structure of This Book 40 Summary and Synthesis 41 Key Definitions 42 2. Biological Chemistry: Building Cells from Elements 44 The Basis for Selection of Carbon, Nitrogen, and Phosphorus in Biochemical Evolution 45 The Elemental Composition of Major Biochemicals 51 Cell Components: The Elemental Composition of Cellular Structures 66 Summary and Synthesis 78 3. The Stoichiometry of Autotroph Growth: Variation at the Base of Food Webs 80 Cellular and Physiological Bases 81 C:N:P Stoichiometry of Entire Higher Plants 87 Autotrophs in Captivity 89 Theories of Autotroph Stoichiometry 107 Autotrophs in the Wild: Oceans, Lakes, and Land 120 Causes of Variation in Autotroph C:N:P in Nature 127 Catalysts for Ecological Stoichiometry 132 Summary and Synthesis 133 4. How to Build an Animal: The Stoichiometry of Metazoans 135 Biochemical and Biological Determinants of Body Elemental Composition 136 Invertebrate Stoichiometry: C:N:P in Zooplankton and Insects 138 Determinants of C:N:P in Invertebrates: The Growth Rate Hypothesis 142 Molecular Biology and the C:N:P Stoichiometry of Growth, or Ecosystem Scientists Go Astray 150 A Simple Molecular-Kinetic Model of the Growth Rate-C:N:P Connection 160 Structural Investment and the Stoichiometry of Vertebrates 168 Elemental Composition and Body Size 171 Catalysts for Ecological Stoichiometry 175 Summary and Synthesis 178 5. Imbalanced Resources and Animal Growth 179 Mass Balance in Growth Processes 180 Maximizing Yield in Chemistry and in Ecology 185 Limiting Factors for Heterotroph Growth: Development of Threshold Element Ratio Theory 189 A New Minimal Model of the Stoichiometry of Secondary Production 197 Some Real World Problems in Stoichiometric Balance 205 Growth Efficiency 222 Catalysts for Ecological Stoichiometry 227 Summary and Synthesis 229 6. The Stoichiometry of Consumer-Driven Nutrient Recycling 231 A Brief History of Studies of Consumer-Driven Nutrient Recycling 232 Stoichiometric Theories of Consumer-Driven Nutrient Recycling 235 Evidence That Consumers Differentially Recycle Nitrogen and Phosphorus 245 Microbial Mineralization 249 The Stoichiometry of Consumer-Driven Nutrient Recycling by Vertebrates 252 Catalysts for Ecological Stoichiometry 259 Summary and Synthesis 260 7. Stoichiometry in Communities: Dynamics and Interactions 262 Species Interactions 264 Positive Feedbacks and Multiple Stable States 277 Trophic Cascades 291 Light: Nutrient Effects at the Community Level 298 Feedbacks Owing to the Constraints of Stuff: C:N Ratios in Tall-Grass Prairie 307 Catalysts for Ecological Stoichiometry 308 Summary and Synthesis 310 8. Big-Scale Stoichiometry: Ecosystems in Space and Time 313 Empirical Patterns in Ecosystem Stoichiometry 315 Linkages in the Stoichiometry of Biomass Yield: Using One Substance to Obtain Another 336 Nutrient Use Efficiency at the Ecosystem Level 341 The Stoichiometry of Food-Chain Production: A New Term, Carbon Use Efficiency 348 The Fate of Primary Production 350 Global Change 354 Catalysts for Ecological Stoichiometry 364 Summary and Synthesis 366 9. Recapitulation and Integration 370 Recapitulation 370 Integration: Toward a Biological Stoichiometry of Living Systems 376 Appendix 382 Literature Cited 385 Index 431
图书 Communities and Ecosystems: Linking the Aboveground and Belowground Components 作者 David A. Wardle 出版年代 Paper | 2002 | $61.00 / 41.95 400 pp. | 5 x 8 | 58 line illus. Most of the earth's terrestrial species live in the soil. These organisms, which include many thousands of species of fungi and nematodes, shape aboveground plant and animal life as well as our climate and atmosphere. Indeed, all terrestrial ecosystems consist of interdependent aboveground and belowground compartments. Despite this, aboveground and belowground ecology have been conducted largely in isolation. This book represents the first major synthesis to focus explicitly on the connections between aboveground and belowground subsystems--and their importance for community structure and ecosystem functioning. David Wardle integrates a vast body of literature from numerous fields--including population ecology, ecosystem ecology, ecophysiology, ecological theory, soil science, and global-change biology--to explain the key conceptual issues relating to how aboveground and belowground communities affect one another and the processes that each component carries out. He then applies these concepts to a host of critical questions, including the regulation and function of biodiversity as well as the consequences of human-induced global change in the form of biological invasions, extinctions, atmospheric carbon-dioxide enrichment, nitrogen deposition, land-use change, and global warming. Through ambitious theoretical synthesis and a tremendous range of examples, Wardle shows that the key biotic drivers of community and ecosystem properties involve linkages between aboveground and belowground food webs, biotic interaction, the spatial and temporal dynamics of component organisms, and, ultimately, the ecophysiological traits of those organisms that emerge as ecological drivers. His conclusions will propel theoretical and empirical work throughout ecology. Reviews: Highly recommended for all ecologists.-- Choice I suspect that this book, if for nothing else than for the sheer weight of its intellectual synthesis, will be among classics for many years to come.--Patrick Bohlen, Ecology Endorsements: After a long phase of specialization and splinter, ecologists are again converging on the ecosystem. In this book, David Wardle shows that he is qualified by experience and instinct to play a leading role in this exciting quest.--J. P. Grime, University of Sheffield Over much of the twentieth century, there has been a disconnect between studies of above-ground and below-ground organisms at both the community and ecosystem levels. Many of the below-ground studies proceeded in relative isolation or were treated by ecologists at a 'black box' level. David Wardle's new book is truly a quantum leap forward in uniting studies of terrestrial ecosystems. It explains the concepts and mechanisms of community and ecosystem processes within the framework of a masterful review and synthesis of the world literature--leading us toward an ecological 'unified field theory' (pun intended).--David C. Coleman, University of Georgia This book is a benchmark and bellwether for a large volume of science that is being and will be conducted in this decade. It will be of value to both those scientists with casual interests in the topic and to the experts, because it provides short summaries and syntheses of findings as well as an in-depth analysis of available data.--Timothy Seastedt, University of Colorado 图书内容 TABLE OF CONTENTS: Acknowledgments vii Chapter 1: Introduction 1 Chapter 2: The Soil Food Web: Biotic Interactions and Regulators 7 Controls: Top Down, Bottom Up, and Productivity 9 Regulation by Resources and Predation in Soil Food Webs 16 Litter Transformers, Ecosystem Engineers, and Mutualisms 37 The Functionality of Soil Food Webs 43 Stability and Temporal Variability 48 Synthesis 53 Chapter 3: Plant Species Control of Soil Biota and Processes 56 Plant Species Effects on Soil Biota 57 Links among Plant Species, Soil Biota, and Soil Processes 68 Temporal and Spatial Variability 73 Plant Traits, Strategies, and Ecophysiological Constraints 83 Soil Biotic Responses to Vegetation Succession 97 Synthesis 103 Chapter 4: Belowground Consequences of Aboveground Food Web Interactions 105 Individual Plant Effects 106 Dung and Urine Return 114 Effects of Palatability Differences among Plant Species 117 Spatial and Temporal Variability 130 Consequences of Predation of Herbivores 132 Transport of Resources by Aboveground Consumers 134 Synthesis 136 Chapter 5: Completing the Circle: How Soil Food Web Effects Are Manifested Aboveground 138 The Decomposer Food Web 140 Nitrogen Transformations 152 Microbial Associates of Plant Roots 157 Root Herbivores 169 Physical Effects of Soil Biota 173 Soil Biotic Effects on Aboveground Food Webs 175 Synthesis 181 Chapter 6: The Regulation and Function of Biological Diversity 183 Assessment of Soil Diversity 184 Stress and Disturbance as Controls of Soil Diversity 187 Biotic Controls of Diversity 194 The Enigma of Soil Diversity 203 Diversity of Soil Organisms over Larger Spatial Scales 205 Biodiversity and Ecosystem Function 209 Synthesis 236 Chapter 7: Global Change Phenomena in an Aboveground-Belowground Context 239 Species Losses and Gains 240 Land Use Changes 253 Carbon Dioxide Enrichment and Nitrogen Deposition 265 Global Climate Change 281 Synthesis 292 Chapter 8: Underlying Themes 295 References 309 Index 387
图书 Resource Strategies of Wild Plants 作者 Joseph M. Craine 出版年代 Paper | 2009 | $45.00 / 30.95 Cloth | 2009 | $99.50 / 69.95 352 pp. | 6 x 9 | 2 halftones. 37 line illus. 1 table. e-Book | 2009 | $45.00 | ISBN: 978-1-4008-3064-0 介绍 Over millions of years, terrestrial plants have competed for limited resources, defended themselves against herbivores, and resisted a myriad of environmental stresses. These struggles have helped generate more than a quarter million terrestrial plant species, each possessing a unique strategy for success. Yet, as Resource Strategies of Wild Plants demonstrates, the constraints on plant growth are universal enough that a few survival strategies hold true for all seed-producing plants. This book describes the five major strategies of growth for terrestrial plants, details how plants succeed when resources are scarce, delves into the history of research into plant strategies, and resets the foundational understanding of ecological processes. Drawing from recent findings in plant-herbivore interactions, ecosystem ecology, and evolutionary ecology, Joseph Craine explains how plants attain available nutrients, withstand the immense stresses of drying soils, and flourish in the race for light. He shows that the competition for resources has shaped plant evolution in newly discovered ways, while the scarcity of such resources has affected how plants interact with herbivores, wind, fire, and frost. An understanding of the major resource strategies of wild plants remains central to learning about the ecology of plant communities, global changes in the biosphere, methods for species conservation, and the evolution of life on earth. Joseph M. Craine is assistant professor of biology at Kansas State University. He has conducted research throughout North America, New Zealand, Australia, and South Africa. Review: This work would be excellent for a seminar/discussion-style course for undergraduate and especially graduate students.-- Choice Endorsements: This book provides an in-depth historical review and novel synthesis of resource strategies in wild plants. Craine identifies distinct strategies associated with high resource supply and limitations of nutrients, light, water, and carbon dioxide. This multiresource approach to plant strategies overcomes inconsistencies in earlier strategy frameworks and is well-grounded in ecological, biogeochemical, and evolutionary mechanisms that have shaped patterns of terrestrial plant diversity. This book will be a valuable resource for anyone interested in the functional diversity of the planet and its likely future changes.--F. Stuart Chapin III, University of Alaska, Fairbanks Accessible, concise, and clear, this book reviews and analyzes the main conceptual advances in plant ecology. A timely revision of plant strategies, it addresses fundamental questions, defines disciplines, and moves science forward.--Francisco I. Pugnaire, Spanish National Council for Scientific Research Joseph Craine is one of the few people in the world with the expertise to have written this book, and he has done it with rigor, substance, and style. There is nothing comparable in the ecological literature. Logically developed, well researched, efficient, and engaging, this book should be required reading for anyone with a professional interest in plant ecology.--Matthew P. Ayres, Dartmouth College 图书内容 TABLE OF CONTENTS: Preface xi Acknowledgments xv Abbreviations xvii CHAPTER 1: The Basis for Plant Strategies 1 Assessing Natural Selection 1 From Single Traits to Multitrait Strategies 5 Quantifying Plant Traits and Strategies 8 Ranking Strategies 9 Synthesis 13 CHAPTER 2: The History of Plant Strategies 15 Nutrients and the History of Plant Strategies 15 Grime 19 Chapin 26 Tilman 33 Laying the Foundation of Plant Strategies 41 CHAPTER 3: Stress and Disturbance 45 Defining Stress and Disturbance 45 Major Causes of Stress and Disturbance 48 How Herbivory Works 50 Growth in the Face of Stress and Disturbance 55 Responding after Stress and Disturbance 61 The Links to Resource Availability 62 Summary 62 CHAPTER 4: Resource Limitation 64 The Concept of Single-Resource limitation 65 History of the Nitrogen Cycle Concept 68 Pulses or Slow Bleeds? 75 Primer on the Phosphorus Cycle 79 Co-limitation in a Post-Liebigian World 80 Evaluating Costs in a Co-limited World 84 Trade-offs in Use Efficiency in a Co-limited World 87 Summary 89 CHAPTER 5: Competition for Nutrients and Light 91 Definitions and Types of Competition 92 Competition for Nutrients under Uniform Supplies 94 How Much Root Length? 104 Interference Competition 106 Competition for Nutrients under Heterogeneous Supplies 107 Competition for Light 109 Synthesis 114 CHAPTER 6: Comparing Negative Effects 119 Comparing Negative Effects 120 How to Measure the Importance of Stress and Disturbance in Environments 122 How to Measure the Importance of Stress and Disturbance in the Natural Selection of a Species 130 Importance of Factors at Low Nutrient Supply 132 Importance of Factors at High Nutrient Supply 139 The Relative Importance of Factors 145 Synthesis 146 CHAPTER 7: The Low-Nutrient Strategy 149 Physiological Traits 151 Whole-Plant Traits 169 Effects on Nitrogen Cycling 171 Revising the Low-Nutrient Strategy 173 Significance of Traits in Strategy 187 Synthesis 199 CHAPTER 8: The High-Resource Strategy 202 The Scope of This Chapter 204 Physiological Traits 205 Whole-Plant Traits 212 Effects on Nutrient Cycling 213 Revising the High-Resource Strategy 213 Significance of Traits in Strategy 217 Why the Race Ends 223 Synthesis 224 CHAPTER 9: The Low-Light Strategy 227 Physiological Traits 229 Whole-Plant Traits 233 Effects on Nutrient Cycling 236 Traits under High Light 236 Why These Patterns 239 The End of the Second Stage of Competition 246 Synthesis 248 CHAPTER 10: The Low-Water and Low-CO2 Strategies 251 Water 251 Carbon Dioxide 268 Summary 279 CHAPTER 11: A Synthesis of Plant Strategies 282 Application and the Way Forward 285 Genetics, Pleiotropy, and Plasticity 286 Limitation 287 Competition 289 Defense and Herbivory 290 Mechanisms of Coexistence 292 Biogeographic Patterns and Invasions 293 Global Change 295 Tree of Life 298 Bibliography 301 Index 327
Steven D. Allison, Matthew D. Wallenstein, Mark A. Bradford. Soil-carbon response to warming dependent on microbial physiology . Nature Geoscience , 2010; DOI: 10.1038/ngeo846 全球变暖的情况下，微生物的生理活动可能决定了土壤中向大气释放CO2的量。 多数生态系统模型都预测，随着全球温度的升高将会刺激微生物对土壤C的分解活动，从而形成一个正反馈。但是来自UC Irvine, Colorado State University and the Yale School of Forestry Environmental Studies 等单位的科学家发现随着全球温度的升高，土壤微生物在将土壤中的C转变为CO2的过程的效率将随时间的推移而降低。 以前的模型中都没有考虑到酶的活性的问题，而这些研究者的模型中考虑了酶活性在温度升高过程的变化情况。微生物产生的酶在土壤有机碳转变为CO2的过程中发挥着重要作用。
如果我有这个财力的话,我想在每个城市的大广场上,树立一座倒计时牌,让我们把计数值设置为511339078292,每过一天,减去一个1。 不用太多的算术，你就可以知道这是大得恐怖的数字，时间指向是14亿年以后。我们是群朝不保夕的生物，连14年后的CPI数字都不知道，谁会有闲工夫去知道14亿年后将发生什么？吃饱了撑的。 但是，不管怎么议论，哪怕人们推倒了计数牌，或者那一堆金属、ＬＥＤ和集成电路早已化成了灰，变成了粉末，你压缩了时间，观察山岭隆起又被风化夷平，海进然后又海退，大陆之间合并，复又分离，也不管生物变化了几茬，人类存在或者不存在，那个数字仍在跳动。 如果在那个计数牌存在的远比14亿年短暂时间里，应该起个名字的话，我想最合适的是距离世界末日还有天。 长周期来看，太阳的亮度在缓慢的提高，并且自从她进入主序星阶段以来，已经这样缓慢提高了40多亿年，当然地球上复杂的生态系统会做出负反馈调节，但是任何调节都是有限度的。 在雏菊世界里，开始时，行星表面是变换的黑白斑点，到了最后，生态系统负反馈调节的一切裕如度都用尽了，白斑点扩大开来，完全吞没了黑斑点，一个计算机中想象的行星走进了它的末日。 地球和她表面的一切生命，也有末日，60亿年后，增加的太阳亮度将使得地球移出适居带(Habitable zone)外，那时候，除了地下生存的微生物，我们熟悉的一切：鱼，鸟，昆虫，树，蓝色的大海，蓝色的天空，都将走入历史，而且永远不会再出现了。地球的结局大约是这样的：温度越来越高，随着海洋的蒸发，水汽越来越浓，永远不会有晴天，天空永远被云笼罩，可是红外辐射仍透过云进入，温度仍在持续上升，最后，海洋彻底蒸发完毕了，大气浓密得如同金星，失控的温室效应炙烤着大地，没有水，将二氧化碳吸收为碳酸岩石的化学变化终止了，更多的温室气体进入大气，也许那时地球的表面会有比金星凉爽一点的温度大约140℃~170℃。地表将不会存在任何液态水。 跟所有邪教不同的是，公众不会对14亿年以后的事情恐慌，因此也不存在为了把人拉入某一教义的欺骗。但这跟一切宗教或者传说的末日不同，那个地球末日是真实的，可信的。在此之前，地球会有数不清的灾难：地震台风、火山爆发、小行星和彗星的陨落，磁极倒转，冰期和暖期，但地球有生命的38亿年来早就经历了无数这样的灾难，没有什么灾难有能力把地球同学从生命行星的班级中开除，但到那时候，地球是绝无幸免的可能了。 14亿年太漫长，也许远超过了我们的理解能力之外，但我们站在这里，有思考的能力，懂得了一点点关于宇宙的知识，有能力做出一点预言，不是依靠这几十年，几百年，几千年，甚至不是依靠人类进化的三百万年，而是依赖着从单细胞生命以来38亿年的进化。 地球上的生命是个暂态过程，如果用百分比计算的话，我们大约站在进度条的73%的位置上，14亿年，对于生命的历程，还剩下27%。 如果人绝灭了，大约我们的思想也不可能流传下去。那么，大约还要多少年地球才能进化出有智慧的生命？这些生命又还要花多少年才能懂得科学，能预测地球未来的命运？直到他们明白地球上生命的命运，此时还有多少资源可供他们去消耗，以便在毁灭日到来之前，在其他星球上延续地球的生命？ 他们面临的情况大概比我们更紧迫，更少的资源，抢救地球生命的可能性也就更加渺茫。 唯一让地球生命延续下去的可能性，只存在于星际航行之中。幸而，我们现在还有足够的时间和资源开发星际航行技术，但如果我们忽视这点，绝灭就是整个使用DNA的生态界不可避免的命运。 （If there are civilizations elsewhere in the universe） Their eventual choice, as ours, is spaceflight or extinction. Carl Sagan 他们的最终选择，跟我们的一样，要么星际航行，要么绝灭 卡尔萨根
Small ecosphere are easy to made on Earth, putting some aquatic plants and animals and bacteria in a glass globe, let sunlight the glass globe, and the omnisealed tiny ecosystem can endure 10 ~ 30 days. Now condiser the Mars enviroment, since sunlight is weaker there, we can change the proportion of plants and animals in the ecosphere, and using glass to isolate ultraviolet, and keep the airpressure, with a isotopic battery to heat the ecosphere in order to keep the enviroment temperature Earth like . So, in theory, life can survive in that enviroment, but no one had test that on Mars, we can make the experiment on Mars, let a unmaned spacecraft carry a ecosphere there(spacecraft can carrying seed of plants and eggs of animals, and let robotic lander to assembly the ecosphere on the Mars). We can prove it is possible to build a self-self-sustaining Ecosystem on Mars. When the experiment is taking on, all Earth life are in a closed glass globe and when it ends, let robotic lander using high temperature(rocket fuel flame thrower) to clean all the remaining possible microbes.So no Earth microbe may pollute Mars.
爱上芦苇地 With his ear to the reedstems, caught at intervals, something of what the wind wet wispering so constantly among them. the wind playing in the reeds and rushes and osiers (Kenneth Grahme, 1908, The Wind in the Willows ) Even now, there are only few that go down into the reedbeds for pleasure or profit (profit being either income or the advancement of science). Those of us who do, find the pleasure as well as the profit. 'Solitary' is the proper word to describe being all day surrounded by reeds, seeing only reeds and sky, hearing only reeds and birds. A unique experience (Sylvia Haslam, 2003, Understanding Wetlands: Fen, bog and marsh ) 前辈是如此描述的芦苇地，我能体会到Haslam那个solitary的时候，是我第一次在芦苇丛里迷失方向的时候，还有次小师弟从芦苇丛里打来求救电话，他说他找不到出来的路了~不过都是有惊无险。站在3-4m多高的芦苇丛里，你能看到的只有头上的天空和密密的芦苇枝，偶尔从你身边经过的小鸟，还有地上爬满的螃蟹和芦苇枝上各种虫子，不过我相信在英国的科研工作者进入芦苇地里感觉会很不一样，因为他们的芦苇只有不到2m高。不钻进芦苇丛里当然看到是大片的芦苇，还有风起芦苇浪啦~ 这个图也许可以想象一下站在芦苇丛里的感觉~ 之所以关注芦苇，起源于一种鸟震旦鸦雀。而震旦鸦雀的关注，还得到本科毕业那会儿（2002年），当年导师提前带我出去野外，去的是南汇边滩（当年的南汇边滩芦苇地还是有的，当年的南汇边滩是现在的临港新城，出了城就是江和海，和那个新奥尔良类似的，嘿嘿，没恶意的），在那的芦苇地里第一次见到了震旦鸦雀，虽然那时候已经开始和鸟友出去观鸟，但是那之前还没有见过震旦鸦雀，所以当时还是个个人新记录~，也因此给了导师一个吹的机会，依稀记得导师当年说，国内震旦鸦雀的第一个研究是华师大的一位先生做的（其实是华师大生物系毕业的），主要是种群生态学的一些东西，而对于其他的方面了解很少，比如食性等等~~~总而言之，导师似乎有意把这个作为研究的对象~~，不过后来因为种种原因一直没有机会去深入了解这个震旦鸦雀，直到2006年，才开始有了大量的时间和精力投入到芦苇地里去关注震旦鸦雀。 这个就是震旦鸦雀了，不进入芦苇丛里比较难见到的，可能也是早期对于他的了解很少的原因，就如Haslam说的，很少有人愿意跑到芦苇地里去~~ 虽然我有时间和精力去调查震旦鸦雀，我的主攻方向是湿地生态恢复鸟类栖息地营建的相关生态学问题，震旦鸦雀只能算是顺带着的兴趣，而刚好栖息地营建实验的基地是在一大片芦苇地中，机不可失啊，于是经常徘徊在芦苇地里，逐渐陷入到这片芦苇地里。 震旦鸦雀对芦苇的依赖性极强，他是他唯一的栖息地，他依赖他获取绝大部分食物，他依赖他获取巢材、提供巢址，他的一生都在芦苇地里渡过~在ecological specialization里有habitat specialization，foraging specialization，behavior specialization，dieatry specialization~震旦鸦雀大概可以占到好几个，而这一切都起因于震旦鸦雀分布在芦苇地里。因为震旦鸦雀取食芦苇上的昆虫，我想知道芦苇地里的昆虫，因为震旦鸦雀对芦苇的依赖，我想知道芦苇的变化对震旦鸦雀的影响，我也想知道震旦鸦雀对芦苇是不是有影响，还有那些比如爱爬芦苇杆的螃蟹，我想知道这些螃蟹是不是会影响震旦鸦雀繁殖，我也想知道震旦鸦雀是不是意识到这些爱爬芦苇杆的螃蟹是个危害，还有螃蟹会吃芦苇叶子，这些螃蟹的行为是不是会影响芦苇、进而影响震旦鸦雀，这些螃蟹行为会不会影响芦苇上的昆虫，进而影响震旦鸦雀的食物获取~~总而言之，芦苇地里发生的一切都是我想知道。也许最后，我想知道的是震旦鸦雀的特化是怎么来的，这种特化又是如何适应芦苇地生活的。 喜欢爬上芦苇枝去吃芦苇叶子的无齿螳臂相手蟹，这种螃蟹在长江口的芦苇地里数量巨大，不过传统的观点认为他是碎屑食性的，主要吃凋落物；最近稳定性同位素的证据表明他主要吃底栖藻类；而我观察下来，他吃芦苇叶子的量绝不会小于底栖藻类，我更偏向于他是一种herbivore~ 爬在野茭白上的无齿螳臂相手蟹。野茭白相对于芦苇来说，矮小而植株稀疏，无齿螳臂相手蟹会在夜深人静的时候溜到芦苇地旁边的野茭白地里来吃茭白叶子，这些茭白往往被吃的光光的，herbivore的不对等取食作用(asymmetry)，也许是盐沼往往形成单一种群落的原因之一呢，呵呵 悦目金蛛，捕食性节肢动物也大量存在于芦苇地里，这些捕食者的存在也会影响芦苇上的昆虫分布等，而螃蟹的攀爬又会影响蜘蛛的分布，这其中的关系想来是很复杂了。以往对于湿地生态系统的生物群落相互关系的研究按照两条线来的多，一条是底栖动物植物环境，还有一条是陆生节肢动物植物环境，前一条可以看成是湿的，后一条可以看成是干的，也颇有湿地是水生生态系统和陆生生态系统交界类型的特征哈，不过我想底栖动物和陆生节肢动物之间相互联系也是完全可能的，螃蟹和蜘蛛的关系及其对herbivore的影响，也许是个起点~ 芦苇日仁蚧或者宫仓仁蚧，山东芦苇营生的人叫他苇虱。数量巨多，躲在芦苇叶鞘下、附着在茎表面，二龄以前可以自由活动，选择芦苇杆，二龄以后就只能附着不动了，雄性个体很少见，见到的都是雌性。这是震旦鸦雀在长江口地区的主要食物之一，因为这虫子全年都有，只要你不把芦苇全收割光。一个朋友说，在黄河口的芦苇丛里，震旦鸦雀也是主要以这种虫子为食，虽然后来在东北也试图去找过这种虫子，没有找到，不知道那边的震旦鸦雀是不是也主要吃这种虫子。这个虫子，日本的研究者Kaneko做了很多工作，不过是关于鸟类取食对他以及他的拟寄生生物（parasitoid）的影响的~ Gall makers，某种芦瘿蚊在芦苇枝上形成的虫瘿，数量也很多，也是震旦鸦雀重要食物之一，不过相对于芦苇日仁蚧来说，取食要难一点。这类昆虫也是很有名的，德国的一个同行Tscharntke（现在改作农业生态系统虫害相关研究了）早期就特别关注过他，这个芦瘿蚊也有大量的拟寄生者，德国同行主要研究了鸟-芦瘿蚊-拟寄生者之间的营养级联关系，当然芦瘿蚊对于芦苇枝的影响也很大。没有去过德国也没有去过日本，同样关注芦苇上昆虫的两位同行Kaneko和Tscharntke的研究中没有同时提到日仁蚧和芦瘿蚊，不知道是不是和这两个类群的分布有关，而在我的研究区域，这两个类群同时存在，而且同样是震旦鸦雀重要的食物~ 某种stem-boring caterpillar，数量巨多，是震旦鸦雀育雏期的重要食物，因为总是躲在芦苇枝茎腔里，取食是最难的了。也是当年Tscharntke很关注的芦苇昆虫，因为在欧洲，这类昆虫会导致芦苇枝死亡，然后长出侧枝，而侧枝又是一些secondary attacker所偏爱的，因此，stem-boring caterpillar在芦苇生境昆虫群落结构中起到相当重要的作用，而且昆虫群落结构的变化也会对芦苇产生相应的影响。不过，在我的研究区域，stem-boring caterpillar伤害芦苇枝以后，不会长出侧枝~估计其在昆虫群落结构变化中的作用远不及欧洲了~ 这就是那片芦苇地所在的地方了，因为科研工作的开展，这片原来是废弃鱼塘的荒地已经成为崇明岛上一个新的旅游热点，据崇明县旅游局曰：2007年，年参观人数80k，可能因为不要门票吧；政府也只有因为这样才愿意给钱做科研，因为这样的科研可以带动当地的经济发展~科研的目的是自然和社会双赢~ (所有照片均为本人拍摄，转载请注明出处，谢谢）
标签: 生态系统
