1. Land(scape) classification (continued) approaches applications

2. Land(scape) classification climatic physiographic vegetative ecosystematic

3. Climatic classification: -climate naturally dictates the major vegetation zones -useful at broad scales, but land units too broad for local level uses

4. http://www.ec.gc.ca/soer-ree/English/vignettes/default.cfm

5. Physiographic classification: -based on landform and soils -based on relatively permanent features, so can be more long-lasting than e.g. vegetation classification alone -lends itself to remote sensing -of limited use for ecological purposes unless combined with vegetation

7. Vegetation classification: -based on vegetation physiognomy floristic composition -integrates the total environment (vegetation is largely determined by climate and physiographic factors…) -but, subject to change – vegetation form and composition also depends on time since last disturbance

8. Ecological Land Classification for Southern Ontario (new): Based on physiognomy (e.g. coniferous forest, thicket swamp) at coarse level, floristic composition (e.g. sugar maple-white ash deciduous forest type) at finer level

9. Ecosystem classification: -incorporates climate, vegetation, soils, landform -usually focuses on vegetation-soil units -more useful in changing landscapes -more useful for ecosyste-based management

11. Land classification systems can be parametric (”bottom-up”)… -classifies land units based on the value of selected parameters (e.g. soil nutrient levels, elevation, height of dominant plants, mean annual temperature) -precise, objective approach….but, difficult to select appropriate attributes and the ‘cut-off’ values between classes …or based on morphological appearance (“top-down”) -uses observations of topography, vegetation to distinguish different land units -can be more subjective…but more intuitive as it is based on obvious distinguishing features

13. Land classification systems can be hierarchical…

14. …or not

15. -Moss has suggested classifying landscapes based on rates of different ecological functions (e.g. productivity, decay)

16. -Land classification is done for a purpose, not as an end in itself -choice of characteristics on which a classification system is based depends on the end use of the system -too many characteristics = small classes (few land units in each class) = less useful for making generalizations -too few characteristics = large classes = not specific enough

17. Choice of criteria should be based on: 1.Accessibility (easy to measure/observe) 2.Significance (how well does the characteristic distinguish one land unit from another?)

18. Applications of land classification systems based on ecosystem characteristics: -forest management -conservation -forest fire control

20. -different classes of jack pine forest may be more or less susceptible to fire -the Northwestern Ontario Forest Ecosystem Classification distinguishes between jack pine-dominated forests based on understory vegetation -the type of understory vegetation partly determines the burn potential of a forest patch -fire control personnel can better predict the behaviour of fire (potential for intensity, spread, etc.), and prioritize control efforts, using the FEC to map out jack pine forest types

24. -ecosystem classification can be used to plan habitat reserves in a managed landscape -setting aside a representative amount of each land type can help to ensure the protection of different habitat types -traditionally, reserves set aside on poor and/or inaccessible land

27. Landscapes – the spatial dimension

28. Categories of landscape elements: describing landscape structure matrix patch corridor mosaic network edge interior total habitat area patch area patch shape connectedness connectivity heterogeneity scale

29. Matrix: -the dominant, all encompassing element in the landscape Patch: -relatively homogenous areas of contrasting habitat matrix patch

31. Carolinian Region: pre-European settlement

32. Carolinian Region: Mid-1990s

33. Both the quantity and quality of patches of a given type will affect the ecological functioning of the landscape (e.g. for wildlife habitat) The habitat quality in a patch is related to its size and shape: -large patches have a high ratio of interior to edge compared to small patches

34. Total area: large patch =2 km 2 Total perimeter length =5 km Total area: small patches =2 km 2 (8 x 0.25 km 2 ) Total perimeter length =14 km !! -for a given total area of a habitat type, fewer, larger patches will have less edge than numerous, small patches

35. -for a given patch area, a circular patch will have less edge than an elongated patch Total area: circular patch =2 km 2 Total perimeter length =5 km Total area: long patch =2 km 2 Total perimeter length =6.84

36. Why do we care how much ‘edge’ there is? -different from interior -more influence from adjacent patches

37. In the case of forest patches in a fragmented landscape, edge habitat has: -different microclimate, e.g. more light availability -more ground vegetation -different species… more ‘pioneers’, opportunistic species

38. The ‘edge effect’ – different microclimate near forest edge vs. interior

39. The ‘edge effect’ – different plant community composition near edge

40. The ‘edge effect’ – can result in more diversity at the forest edge vs. interior forestold field

41. From a study of the effects of forest harvesting on landscape patterns in NB

42. Corridor: -linear elements, may stand alone or link patches together -not necessarily continuous…’stepping stones’ of habitat may also be considered corridors Network: a set of corridors on the landscape

44. Function of corridors: -provide connectivity between patches of habitat -increase the permeability of the landscape -(sometimes a distinction is made between connectivity and connectedness)

45. Function of corridors: -why is more connectivity usually desirable in fragmented landscapes? -is more connectivity always good?

46. From Tewksbury et al., 2002

47. Even in non-terrestrial ‘landscapes’…corridors aid dispersal between habitat patches (this result was found in an estuary, with marine invertebrates moving through corridors and patches of seagrass)

48. The ‘patch/matrix’ view has largely given way to the ‘mosaic’ view landscape is composed of patches of habitat within a ‘hostile’ matrix of non-habitat landscape composed of a collection of patches derived from ‘islands in ocean’ analogy in the real world…the ‘matrix’ is just another habitat type

49. Landscape pattern: -the spatial arrangement of the mosaic and networks -the scale or grain with which you view or consider the landscape also influences the pattern you perceive fine grain = lots of detail cropland forestold forest young forest beans wheat corn hay coarse grain = little detail

50. -what constitutes a patch in this photo….forest cover in general, or each different type of forest cover? -fine grain vs. coarse grain view depends on the question you are asking about the landscape, e.g. the organism you are concerned about

51. -what is continuous is also in the eye of the beholder… -a corridor that is continuous on a coarse scale may be discontinuous on a fine scale

52. Landscape heterogeneity -more heterogeneity = more variety = more “information” contained in the landscape (i.e. more difficult to describe)

53. What causes spatial heterogeneity in a landscape? -environmental variability (e.g. soil texture, elevation) -natural disturbances -anthropogenic disturbances/land use Landscape heterogeneity

55. Tree islands in everglades: ‘hotspots’ for nutrient capture and biodiversity

56. Positive feedbacks lead to island growth

58. Anthropogenic changes in hydrology leading to island loss = homogenization of landscape, loss of a habitat type

60. Landscapes – the temporal dimension -movie -landscape change in Glacier Bay Park: primary succession

61. Tewksbury et al. 2002. Corridors affect plants, animals, and their interactions in fragmented landscapes. Proceedings of the National Academy of Sciences, 99(20): 12923-12926 Pickett and Cadenasso, 1995. Landscape ecology: spatial heterogeneity in ecological systems. Science 269(5222): 331-334 Mladenoff et al. 1993. Comparing spatial pattern in unaltered old-growth and disturbed forest landscapes. Ecological Applications 3(2): 294-306 This week’s readings… (all are available online)