Introduction to Landscape Ecology.ppt

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1、Introduction to Landscape Ecology,What Is Landscape Ecology?,What Is Ecology?,The word ECOLOGY was coined by Ernst Haeckel in 1869. It is derived from the Greek oikos, meaning “household“, “home,“ or “place to live“ and logos, “the study of.“ Haeckels definition: “.the investigation of the total rel

2、ationships of the animal both to its inorganic and its organic environment.“,What Is Ecology? Other definitions I:,“.scientific natural history.“ (Elton 1927) “.the scientific study of the distribution and abundance of animals.“ (Andrewartha 1961) “.the study of the structure and function of nature“

3、 (Odum 1971) “.the study of the adaptations of organisms to their environment“ (Emlen 1973) “.the scientific study of the relationships between organisms and their environments“ (McNaughton and Wolfe 1979),What Is Ecology? Other definitions II:,“.the scientific study of the interactions that determi

4、ne the distribution and abundance of organisms.“ (Krebs 1985) “.the study of the principles which govern temporal and spatial patterns for assemblages of organisms“ (Fenchel 1987) “.the study of the relationships between organisms and the totality of the physical and biological factors affecting the

5、m or influenced by them“ (Pianka 1988),Collectively, these definitions convey the notion that:,The environment influences organisms AND, organisms influence the environmentThe fact that we are breathing oxygen (generated mostly by the process of photosynthesis) is a rather striking example of the po

6、wer of organisms to influence the environment,What do ecologists study? How do ecologists study things?,Experimental papers submitted to the journal Ecology between 1980-86 50% of studies used experimental plots 95% used plots 100m in diameter!,Themes in Landscape Ecology: I. Scaling Issues,How do w

7、e scale up? What is the most appropriate spatial and temporal scale to use when addressing a given question? (see Urban et al. 1987 and others)But waitWhat do we mean by “scale”,Scale: A confusing term,This term is used inconsistently throughout the literature. You will need to learn to read between

8、 the lines to determine how each author intends to use this term. The Turner et al. text (on reserve) (Table 1.1) defines scale as the “spatial or temporal dimension of an object or process, characterized by both grain and extent.”,Scale: A confusing term grain + extent ?,Extent: defined (Table 2.1)

9、 as “the size of the study area or the duration of time under consideration.” Note that this definition includes both a spatial and temporal component Grain: a potentially confusing term. Defined (Table 2.1) as “the finest level of spatial resolution possible within a given data set.” Be careful! So

10、me authors treat grain and scale as equivalent terms!,Which map is “large scale?”,The formal definition of Map scale is counter-intuitive!,Scale: which definition? You need to read between the lines to find out!,Scale: grain + extent? Maps with large extent are usually coarse-grained; fine-grained m

11、aps usually have small extent. Scale: grain only? Large/small Scale: geographers definition or common (incorrect) definition?,Themes in Landscape Ecology: II. The study of larger areas,Implicit in the focus on scaling issues is that Landscape ecology deals with the study of larger areas (landscapes)

12、 than has been the case in “traditional ecology.” How large is a landscape? No hard and fast rules. “a kilometers-wide mosaic over which local ecosystems recur” (Forman 1995) A more general definition that does not require an absolute scale: “an area that is spatially heterogeneous in at least one f

13、actor of interest” (Turner et al. 2001; p. 7),Themes in Landscape Ecology: III. The real world is patchy,Patch: a surface area that differs from its surrounding in nature or appearance (Table 1.1; and see other related terms in this table) Patches can occur in space or time Edge effects matter! Trad

14、itionally, ecologists tried to ignore edges. Sample sites located in the middle of large uniform patches of vegetation.,Themes in Landscape Ecology: IV. Analysis of connectivity in patchy environments,How does the arrangement and characteristic of patches influence ecosystem processes? Wildfire spre

15、ad Juvenile dispersal success Seed dispersal success Hydrologic response,Themes in Landscape Ecology: V. Explicit consideration of the role of humans,Role of humans often ignored when focused on the study of 1m2 plots The role of humans cannot be ignored at the landscape scale (spatial domain) The l

16、egacy of human land use can persist for centuries to millennia (time domain),Themes in Landscape Ecology: VI. Interdisciplinary,Ecology, Biology, Computer Science, Geography, Statistics, Aerospace Engineering (remote sensing), Physics For each paper you read this quarter, take a moment to look at th

17、e mailing address of the authors. What academic department are they from? What agency? This gives you a hint about the perspective they bring to any given analysis,Tools for Landscape Ecology: I. Computers,fast, cheap computers and they keep getting faster Processing speed closely linked to transist

18、or density. This has been doubling about every 18 months for nearly 40 years (Moores law) Common desktop computers capable of gigaFLOPS,Science 1996. 274:1834,Tools for Landscape Ecology: II. Statistics,Shift from parametric statistics (t-test, ANOVA, linear regression) to spatial statistics Geostat

19、istic: exploiting spatial autocorrelation,Tools for Landscape Ecology: III. GIS and Remote Sensing,Made possible by improvements in computers These tools have made it possible to work effectively with large spatial data sets (maps). Often used as tools to prepare datasets for use in various models G

20、IS also often used to display and help analyze output from these models.,Tools for Landscape Ecology: IV. Landscape Metrics,As with many new fields of study, the early years of landscape ecology (the 1980s) focused on the development of tools to describe landscape patterns These metrics include, pat

21、ch size, shape, proximity, edge density, dominance, diversity, fractal dimension, and many more,Tools for Landscape Ecology: V. Models,These take many forms. We will expand on this in a week or so.,Origins of Landscape Ecology: The European School,German biogeographer, Carl Troll coined the term lan

22、dscape ecology in 1939 Emphasis on typology, classification, nomenclature and mostly concerned with the “built” (human) environment In the U.S., this perspective is most often found in Landscape Architecture, Planning or Design schools rather than in Biology, Environmental Science or Ecology program

23、s,Origins of Landscape Ecology: The American School,Also found in Australia and elsewhere, including in Europe Comparatively young; launched by a few meetings in the early 1980s (Risser et al. 1984) More focused on natural or semi-natural systems Much more heavily invested in theory and models Most

24、practitioners are in Biology, Environmental Science, Ecology, Natural Resources or Geography programs or Natural Resources Management Agencies,What is Landscape Ecology?,focuses on (1) the spatial relationships among landscape elements, (2) the flows of energy, mineral nutrients, and species among t

25、he elements, and (3) the ecological dynamics of the landscape mosaic through time (Forman 1983),What is Landscape Ecology?,.focuses explicitly upon spatial patterns. Specifically, landscape ecology considers the development and dynamics of spatial heterogeneity, spatial and temporal interactions and

26、 exchanges across heterogeneous landscapes, influence of spatial heterogeneity on biotic and abiotic processes, and management of spatial heterogeneity (Risser et al. 1984),What is Landscape Ecology?,.is motivated by a need to understand the development and dynamics of pattern in ecological phenomena, the role of disturbance in ecosystems, and characteristic spatial and temporal scales of ecological events (Urban et al. 1987),What is Landscape Ecology?,.emphasizes broad spatial scales and the ecological effects of the spatial patterning of ecosystems (Turner 1989),