BIOL 4120: Principles of Ecology Lecture 5: Biome Concept in Ecology

1. BIOL 4120: Principles of Ecology Lecture 5: Biome Concept in Ecology Dafeng Hui Room: Harned Hall 320 Phone: 963-5777 Email: dhui@tnstate.edu Biogeography is the study of the spatial or geographical distribution of organisms (both present and past). Biogeographical ecology: study spatial and geographical distribution of organisms and climate. The goal is to describe and understand the processes responsible for the many Patterns in the distribution of species and larger taxonomic groups. This chapter, we will focus on terrestrial ecosystems. We will only look at the large-scale distribution of biomes in terrestrial ecosystems. Biogeography is the study of the spatial or geographical distribution of organisms (both present and past). Biogeographical ecology: study spatial and geographical distribution of organisms and climate. The goal is to describe and understand the processes responsible for the many Patterns in the distribution of species and larger taxonomic groups. This chapter, we will focus on terrestrial ecosystems. We will only look at the large-scale distribution of biomes in terrestrial ecosystems.

2. When P is higher than T, water is plentiful, and plant productition is limited by T Conversely, when T is higher than P, plant productivity is limited by P. (20 mm precipitation=10oC T, balanced) When P is higher than T, water is plentiful, and plant productition is limited by T Conversely, when T is higher than P, plant productivity is limited by P. (20 mm precipitation=10oC T, balanced)

4. World Wildlife Fund (WWF) recognizes 14 biomes. Here nine. World Wildlife Fund (WWF) recognizes 14 biomes. Here nine.

6. Also called deciduous forest Growing seasona 130-180 days P > T Decidous forests are dominant form, usually have a layer of smaller trees and shrub as understory In part of this zone, when soil is sandy and nutrient poor, needle-leaf forest such as pine doninants Fires are frequent, trees are able to resist fire demange.Also called deciduous forest Growing seasona 130-180 days P > T Decidous forests are dominant form, usually have a layer of smaller trees and shrub as understory In part of this zone, when soil is sandy and nutrient poor, needle-leaf forest such as pine doninants Fires are frequent, trees are able to resist fire demange.

7. Temperate seasonal forest Forest ecosystems dominate the wetter regions of the temperate zone Deciduous forest covered large area of Europe and China, but mostly converted to croplands, only exist in eastern China Southern Hemisphere, temperate evergreen forest become predominant North America, deciduous forests consist of a number of associations (next slide) Asiatic broadleaf forest found in eastern China, Japan, Korea is similar to the North American deciduous forest

8. Mesophytic forest: Being grow or adapted to moist environmentMesophytic forest: Being grow or adapted to moist environment

9. Warm temperate climate near Pacific coast; mild winter, heavy winter rains; Support extremelly tall evergreen forest: 60-70m or even 100m Compared to tropical forest, few species are supported here. Warm temperate climate near Pacific coast; mild winter, heavy winter rains; Support extremelly tall evergreen forest: 60-70m or even 100m Compared to tropical forest, few species are supported here.

10. Rainfall: 30 to 80 cm, infrequently Growing seaon: 120-300 days (north to south) Also called praries (N.A) and steppes (central Asia) Grassland soil: rich in organic matter (low acidity, not heavyly leached) Vegetation: grasses, 2m (tall grass, moister; or 0.2m in more arid regions) and forbs are anundant Fire: important. Grasses have zhizomes, resist fire and shoots can respount. Or seeds are fire resist. When P is between 25 and 50cm, desert: west US, Great Basin of west US. Vegetation: north, Sagebrush; south: juniper and pinon trees ET>P Fire: infrequently, low fuel Overgrazing could convert dry grassland into desert. Rainfall: 30 to 80 cm, infrequently Growing seaon: 120-300 days (north to south) Also called praries (N.A) and steppes (central Asia) Grassland soil: rich in organic matter (low acidity, not heavyly leached) Vegetation: grasses, 2m (tall grass, moister; or 0.2m in more arid regions) and forbs are anundant Fire: important. Grasses have zhizomes, resist fire and shoots can respount. Or seeds are fire resist. When P is between 25 and 50cm, desert: west US, Great Basin of west US. Vegetation: north, Sagebrush; south: juniper and pinon trees ET>P Fire: infrequently, low fuel Overgrazing could convert dry grassland into desert.

11. Grassland ecosystems Rainfall is very important: 250 to 800 mm Other factors: fire, and human activity (convert grassland to desert by overgrazing) Area: dropped from 42% to <12% of original size Location: mid-latitudes in mid-continental regions Typical: prairies of North America, steppes of central Eurasia

12. Figure 23.22Figure 23.22

13. Support grazers, herbiviors, canivoirs Support grazers, herbiviors, canivoirs

14. Figure 23.24Figure 23.24