Presentation is loading. Please wait.

Presentation is loading. Please wait.

habitat interspersion –

Similar presentations


Presentation on theme: "habitat interspersion –"— Presentation transcript:

1 habitat interspersion –
Leopold’s Law of Interspersion

2

3 Human Land Use Practices

4 History of Landscape Ecology
“European School” roots back to those of ecology typing, classifying, naming landscape architecture, planning, designing “American School” young = early 1980’s focus on natural systems theory & models, some field experiments

5 What is Landscape Ecology?
Meta-analysis of papers in Landscape Ecology (Wiens 1992) – 1st 5 yrs of journal Most studies are large scale (landscapes are big) Most studies are descriptive or conceptual Experiments difficult to conduct, thus modeling Emphasis on vegetation pattern / land use pattern Humans = impt. part of systems

6 What is Landscape Ecology?
Hobbs (1997) – 2nd 5 years of Landscape Ecology Less descriptive studies More “methods” and modeling studies, no expts. More quantitative / statistical analysis (spatial stats)

7 Emergence of Landscape Ecology
? Equilibrium View Structure Function ? ? ?

8 Emergence of Landscape Ecology
Structure Function Dynamic View

9

10

11 Ecological Scaling: Scale & Pattern
Acts in the “ecological theatre (Hutchinson 1965) played out across various scales of space & time To understand these dramas, one must select appropriate scale Temporal Scale Spatial Scale Fine Short Coarse Long Speciation Extinction Species Migrations Secondary Succession Windthrow Fire Treefalls Recruitment

12 Ecological Scaling: Scale & Pattern
Regional Scale (thousands of ha) Local Scale (4 ha plots) American Redstart Least Flycatcher American Redstart Least Flycatcher

13 Ecological Scaling: Definitions
Ecological scale & cartographic scale are exactly opposite Ecological scale = Cartographic scale =

14 Ecological Scaling: Components of Scale
Grain = finest component of environment that can be differentiated up close Extent = range at which a relevant object can be distinguished from a fixed vantage point Extent Grain Fine Coarse Scale

15 Ecological Scaling: Components of Scale
)

16 Identifying the “Right” Scale(s)
No clear algorithm for defining Autocorrelation & Independence Life history correlates Dependent on objectives and organisms Multiscale analysis! e.g., Australian leadbeater’s possum

17 Multiscale Analysis Species-specific perception of landscape features : scale-dependent e.g., mesopredators in Indiana Modeling species distributions in fragmented landscapes

18 Spatial and Temporal Ecology of Raccoons

19 Gehring and Swihart Biological Conservation 109:

20 Brown and Litvaitis. 1995. Canadian Journal of Zoology
73:

21 Hierarchy Theory Lower levels provide mechanistic explanations
Higher levels provide constraints

22 Scale & Hierarchy Theory
Hierarchical structure of systems = helps us explain phenomena Why? : next lower level So What? : next higher level minimum 3 hierarchical levels needed

23 Constraints (significance) Level of Focus (level of interest) Components (explanation)

24 Landscape Pattern Landscape Components
(attributes of features or spatial elements) landscape are comprised of: - corridors - patches - matrix

25 Landscape Pattern Landscape Components
(attributes of features or spatial elements) landscape are comprised of: - corridors - patches - matrix Composition Configuration Connectivity Relative to landscape spatial elements….

26 How much of the area is comprised of each type of spatial element?
How are spatial elements arranged in space? How do these attributes change through time?

27 How does one quantify landscape pattern?
How do biotic communities interact with pattern?

28 Landscape Pattern Patch-Corridor-Matrix Model

29

30

31

32 Landscape Pattern Patches
Defining patches using vector data Digitizing = delineating polygon patches using remotely-sensed data (e.g., DOQ) based on visual interpretation of patch boundaries; subjective, but ground truthing needed DOQ Vector Coverage

33 Landscape Pattern Patches
Defining patches using raster data Satellite sensor = delineating pixel-shaped patches based on spectral signatures; aggregating cells based on shared attributes DOQ Raster Coverage

34 Landscape Pattern Patches
Patch boundaries meaningful only when referenced to particular scale & phenomenon; resolution impt., gradients or discrete boundaries?

35

36 Landscape Pattern Corridors
Definition based on function….. Habitat – increase connectivity by providing breeding habitat…facilitate gene flow Facilitated Movement – increase connectivity by facilitating dispersal, migration, and/or range shifts Barrier or Filter – prohibit (barrier) or impede differentially (filter) movements

37 Landscape Pattern Corridors
Facilitated Movement Corridors

38 Landscape Pattern Corridors
Facilitated Movement Corridors Selectivity (s): degree of discrimination of possible pathways Resistance (k): survival cost per unit time spent in corridor Velocity (v): avg rate of movement through Final evaluation = immigration rate

39 Landscape Pattern Corridors
Barriers & Filters

40 Landscape Pattern Matrix
Most abundant Highest connectivity

41


Download ppt "habitat interspersion –"

Similar presentations


Ads by Google