OBSERVATION 1/2/2010. Nature, Natural History & Ecology. What is NATURE? Nature in the Northwest BIS 241. Jan 4 11, 2010

Transcription

1 What is NATURE? Nature in the Northwest BIS 241 Nature, Natural History & Ecology Jan 4 11, 2010 A STAR on a slide indicates material presented in class has been omitted from these notes on that slide A continuum of human influence on landscapes, biota and processes Natural History: the early study of nature Little human influence Human domination Charles Darwin Galileo OBSERVATION Alexander von Humboldt Natural History: maturing into a modern science The Natural Sciences Observation Astronomy Geography Biology Oceanography Ecology Physics Soil Science Chemistry Geology Atmospheric Science (Mathematics) 1

2 Logos (G) Logos What is Ecology? ECO LOGY Oikos Oikos (G) ECOLOGY Ecological Science is organized largely by studies that emphasize different levels of BIOLOGICAL ORGANIZATION Spatial Scales of Organization in Biological Systems Defining the levels of organization Individual: Population: Community: Ecosystem: Landscape: from Raven & Berg (2004) 2

3 The science of ECOLOGY is organized somewhat along these lines of spatial organization Biogeography Ecological Observations Natural History Ecological Science: Linking Pattern to Process SYNECOLOGY organizational ECOLOGY AUTECOLOGY functional Population Ecology Community Ecology Paleoecology Physiological Ecology Behavioral Ecology Ecosystem Ecology Landscape Ecology Evolutionary Ecology Ecology: Linking Pattern & Process Ecology: Linking Pattern & Process Patterns occur in nature Pattern: Process: Ecologists assume these patterns have some understandable basis; that the world is not governed by chance. Pattern: Isolated patches of biotic development in a barren polar desert landscape The Nature of an Organism s Environment Process:? 3

4 Environmental Factors An Integrated Picture of an Organism s Environment The Holocoenotic Environment Classifying Environmental Factors: The Holocoenotic Environment RADIATION organism WATER Air temperature Fire Humidity The Holocoentoic Environment Insect herbivores Competing shrubs Soil moisture PLANTS FIRE Insect pollinators Soil N Soil OM Storm frequency SOIL ROCKS Billings (1978) The Roles of Environmental Factors Environmental Factors Organisms ADAPT to One central focus area of this class: What are the nature of resources & stresses in different ecosystems? How do organisms solve these problems / situations? ti Examples? 4

5 What is a biological community? How do we define the boundaries of a community? Humans & Boxes: The unnatural nature of boundaries in nature We will examine 2 types of boundaries: 1. Boundaries in space Where does one community / ecosystem stop and another start? What causes things to change through space? 2. Boundaries in time Where does one community / ecosystem stop and another start? What causes things to change through time? Some boundaries are easy to define Boundaries in space: how do communities change across the land? Campus Wetlands: what are the communities? What are we using to draw boundaries? March

6 Some boundaries are not so easy to define Some boundaries are not so easy to define Subalpine fir community Silver fir community Defining communities based upon species composition Humans & Boxes: The unnatural nature of boundaries in nature Community Change through Time Community Change through Time Succession: Lyman Glacier Basin Trees begin to colonize after 60 years 6

7 Succession following abandonment of a farm field in North Carolina Succession following fire in the Pacific Northwest Stages Stage TIME FIRE Stage Succession following fire in the Pacific Northwest TIME Projected Succession in our Campus Wetlands 2006 (5 Yrs) 2016 (15 Yrs) 2026 (25 Yrs) FIRE What is changing through succession? Biological & Structural Diversity: Ecological Restoration: Why is the complexity of physical structure important? Why is the complexity of physical structure important? Forest VERTICAL structure Kruckeberg (1991) Kruckeberg (1991) 7

8 Horizontal Physical Complexity also provides: Campus Wetlands: horizontal structure complexity March 2006 Campus Wetlands: horizontal structure complexity Forested communities Meadow - shrub communities MOUND PIT How do we create such structural complexity in ecological restoration? Restoration intentionally creates varying topography to accelerate the development of habitat diversity Projected Succession in our Campus Wetlands 2006 (5 Yrs) 2016 (15 Yrs) 2026 (25 Yrs) What is changing through succession?

9 Early Succession Aboveground resources (Light, CO 2 ): Plentiful Belowground resources (H 2 O, nutrients): Limited Resources & Succession Ratio of aboveground to belowground resources Late Succession Aboveground resources (Light, CO 2 ): Limited Belowground resources (H 2 O, nutrients): Plentiful Some Important Characteristics of Biological Communities 1. Species Diversity 2. Types of Species A. Dominant Species B. Characteristic Species C. Keystone Species D. Ecological Engineers E. Indicator Species 3. Biological Interactions Species Diversity of Communities So what is diversity? One community Is this 2 nd community just as diverse? Community Diversity Diversity # Species = # Species = Is diversity always desirable? Dominant & Characteristic Species Good community? Bad community? Dominant Species: Characteristic Species: 9

10 Keystone Species & Ecological Engineers Keystone species: Keystone Species & Ecological Engineers Ecological Engineers: keystone species that control the physical structure of the biological community Examples: Pisaster ochraceus Algae, Plankton, Detritus Indicator Species It can be challenging to understand physical & chemical environments How wet is it? Where? When? Indicator Species Plants integrate the environment in TIME & SPACE Indicator Species Species with a narrow tolerance of some environmental factor; and thus whose presence indicates something about that environmental factor Indicator Species Official US Wetland Indicator Status Categories Category Wetland Obligate % Chance species is in a wetland Puget Sound Freshwater Wetlands Fac wet Species Facultative Species Lysichiton americanum (OBL) Salix lucida (FACW+) Fac upland Species Upland Species Which are the good INDICATOR SPECIES? 10

11 Biological Interactions Characterizing interactions between species Ecological Interaction Mutualism (pollination, dispersal) Competition Effect on Species 1 Effect on Species 2 Ecosystems Energy Flow & Food Webs Nutrient Cycling Consumer Resource Interactions Herbivory Predation Disease Energy Flow in Ecosystems Energy Flow in Ecosystems Where does it start? This is called Primary Producers This is a FOOD CHAIN Herbivores (Primary Consumers) Where does it enter ecosystem? Efficiency of Transfer? Carnivores (Secondary Consumers) Terrestrial & Aquatic Food Chains in your reading Energy Flow in Ecosystems Energy Flow is not strictly LINEAR it is much more complex: FOOD WEBS Energy Flow in Ecosystems But what CRITCAL energy flow component is missing? 11

12 Critical Energy Flow Component Missing: Energy Flow in Ecosystems The Hydrologic Cycle consult your reading Matter Cycles through Ecosystems The Carbon Cycle consult your reading The Nitrogen Cycle Note: 1. Major N Pool 2. Inputs 3. Losses 4. Cycling 12

13 The Nitrogen Cycle within an Ecosystem Some Important Lessons of Nitrogen Cycling Consumption Plant uptake (inorganic only) 1. Important to understand INPUTS and LOSSES of nutrients to ecosystem What are the INPUTS & LOSSES? What are the magnitudes of INPUTS & LOSSES? How does human disturbance affect INPUTS & LOSSES? SOIL Organic Nitrogen Amino acids, proteins Fungi, bacteria Inorganic Nitrogen NH + 4 NO - 3 Some Important Lessons of Nitrogen Cycling INPUTS INPUTS > LOSSES? LOSSES > INPUTS? LOSSES = INPUTS? LOSSES 1. Important to understand INPUTS and LOSSES of nutrients to ecosystem What are the INPUTS & LOSSES? What are the magnitudes of INPUTS & LOSSES? How does human disturbance affect INPUTS & LOSSES? 2. Cycling depends upon conversion of organic forms to inorganic Decomposers fungi & bacteria key components Conditions making decomposers unhappy slow nutrient cycling 3. Organisms contain most of the nutrients in many ecosystems Rate of nutrient cycling depends upon rate of death (of all or parts) Removing organisms can remove much of the ecosystem s nutrients Removing Nutrients from Forest Ecosystems INPUTS The bathtub may refill slowly if it is drained LOSSES 13