Introduction to Ecosystem

ClassificationE&FB Chapters 20 & 27

Stern Chapter 27

BEGINNINGof ecosystem classification

Plant geographers :• different parts of the world with similar

climates have similar vegetation• species different, but structure & processes

of ecosystems similar• “correlated” distribution of vegetation types

to climate

BEGINNING of ecosystem classification

“Formations” 1st plants 2nd animals

1. deserts

2. grasslands

3. coniferous forests

4. temperate forests

5. tropical forests

BEGINNING of ecosystem classification

Biogeography :• study of• distribution patterns of organisms,• both past & present.

Patterns called : Vegetation Zones

Vegetation Zones

CLIMATE determines vegetation patterns

I. latitude

II. altitude

III. location on continent

IV. direction of prevailing winds

Vegetation ZonesI . LATITUDE :

Δ N & S from the equator : 1. tropical forests → 2. temperate forests →3. coniferous forests → 4. tundra → 5. ice fields

Vegetation Zones

II. ALTITUDE :• similar Δ as go up in elevation in the

mountains• taiga or boreal region = subalpine life zone• tundra = alpine life zone

World-scale gradients of• temperature more • moisture more

• Dependency ratio in renewable water

Terrestrial Formation Types of the World (Whittaker, 1975)

1. tropical rain forest

2. tropical seasonal forests

3. temperate rain forest

4. temperate deciduous forest

5. temperate evergreen forest

6. subarctic-subalpine needle-leaved forest (taiga)

Terrestrial Formation Types of the World, continued (Whittaker, 1975)

7. subalpine zone forest on tropical mountains (elfinwoods)

8. tropical broad-leaved woodlands

9. thornwoods

10. temperate woodlands

11. temperate shrublands

12. tropical grasslands (savannas)

13. temperate grasslands

Terrestrial Formation Types of the World, continued (Whittaker, 1975)

14. alpine shrublands

15. alpine grasslands

16. treeless arctic plains (tundra)

17. warm semidesert scrubs

18. cool semideserts

19. arctic-alpine semideserts

20. true deserts (subtropical)

21. true deserts (arctic-alpine)

Vegetation Zones

III. Location on continent &

IV. Direction of prevailing winds

+ soil can be

+ fire cycles deciding factors

+ regional climate in some areas

HISTORYof ecosystem classification

1940’s :

Plant formations +

associated wildlife = “Biomes”

Δ between biomes gradual – transition zones :

“ecotones” or “edges”

BIOMES

WARM & MOIST COLD & DRY

• productivity• species diversity• OG matter

BIOMES

WARM & MOIST COLD & DRY

complexity of ecosystems• size of plants• # of vertical strata• number of different species (biodiversity)

Δ typical growth forms

9 Major Terrestrial Biomes(Botany Colouring Book # 96)

1. tundra2. taiga3. temperate forest4. temperate rain forest5. tropical rain forest6. savanna (tropical grassland)7. temperate grassland8. chaparral (scrub forest : maritime, no rain in summer, lots of

fires)

9. desert

E&FB Chapter 27

p.547 : Origin of Plant Hardiness Zones :focused on importance of temperaturep. 549 : Ecoregions (from American perspective)

1961 – Hill (Ontario)“uniform” vegetation zones caused by

interaction between climate (latitude, global position & altitude) soil & topography

E&FB p. 551

“ The ecoregion approach to classification is ecologically more useful than the other classifications

because it relates management strategy to its mapping levels.”

E&FB p. 551 (continued)

“Because all systems operate within the context of larger systems,

knowledge of [the] larger systems allows us to better understand the smaller systems.”

E&FB p. 551 (continued)

“A better understanding of smaller systems allows us to predict the outcome of land management and natural resource development.

It provides a foundation for ecological management of resources.”