Vertebrates dominates the land today, and this includes the growing human population.
Alfred Russell Wallace, who with Charles Darwin coauthored one of the first statements of natursl selection, early realized and set up one of the first systems of biogeographical regions
If in the vast open sea, which what we call pelagic realm, tha primary producers are the pytoplankton, in land habitat we have green plants which dominate the land
Raunkiær’s life forms are based on the place of the plant's growth-point or the renewal bud during seasons , and the corresponding protection provided duringunfavorable cold or dry periods.
The first two groups utilize the more readily decomposable organic substances such as sugars, amino acids, and simple proteins. The cellulose bacteria then work on the more resistant compounds, while the actinomycetes are especially associated with humus, which is the dark, yellow-brown, very resistant end product of the process of decomposition called humification.
A fundamental classification of biomes is:Aquatic biomes (including Freshwater biomes and Marine biomes). Climax vegetation is the vegetation which establishes itself on a given site for given climatic conditions in the absence of anthropic action after a long time (it is theasymptotic or quasi-equilibrium state of the local ecosystem).
Pyramid showing comparison of different biomes based on moisture and temperature.
The extremely cold temperature in this region is not at all suitable for human habitation. The permafrost, which lies about six inches below the surface, remains frozen throughout the year.
Outline<br />Terrestrial Environment<br />Terrestrial Biota and Biogeographic Regions<br />General Structure of Terrestrial Communities<br />Soil Subsystem<br />Vegetation Subsystem<br />Distribution of Major Terrestrial Communties , The Biomes<br />
Terrestrial Environment<br />Climate<br />a. Moisture – major limiting factor on land<br />b. Temprature variations and extremes<br />c. Air circulation – ready mixing and constant content of oxygen and carbon dioxide<br />
2. Substratea. Soil – offers solid support and source of highly variable nutrientsb. Land – provides geographical barriers to free movement<br />
Terrestrial Biota and Biogeographic Regions<br /><ul><li>Specialized organisms includes plants, arthropods, invertebrates, vertebrates, and others.
Microorganisms also play vital roles in all ecosystems, such as bacteria, fungi, protozoans, etc.</li></li></ul><li>Biogeographic Regions<br />Floristic Regions<br />Faunal Regions<br />Zoographic Region<br />Afrotropical=Ethiopian Indo-Malaysian=Oriental <br />Note: Regions Paleartic and Neartic are often united as Holarctic region<br />
General Structure of Terrestrial Communities<br /><ul><li>Autrotrophs</li></ul>-green plants usually dominates the land<br />-obligate autotrophs require only light and mineral nutrients<br />-algae are photosynthetic protists that require vitamins or organic nutrients<br />
Classification of Plant Life-forms<br /><ul><li>Raunkiær system is a system for categorizing plants using life-form categories, devised by Christen C. Raunkiær.
The system is based on the place of the plant's growth-point or the renewal bud during seasons , and the corresponding protection provided during unfavorable cold or dry periods.</li></li></ul><li>Primary Categories<br />1. Phanerophytes- aerial plants; renewal buds exposed on upright shoots<br />
2. Chamaephytes-surface plants; renewal bud at the surface of the ground<br />3. Hemicryptophytes- buds at or near the soil surface <br />Catharanthuspusillus(Tiny_Periwinkle)<br />Daisies or BellisPerennis<br />
4. Cryptophytes-earth plants; buds lying beneath the surface of the ground <br />Geophytes - resting in dry ground, e.g. crocus. <br />Helophytes - resting in marshy ground, e.g. reed mace, marsh-marigold<br />Hydrophytes - resting by being submerged under water<br />
5. Therophytes- annual plants which survive the unfavorable season in the form of seeds <br />6. Aerophytes - obtains moisture and nutrients from the air and rain<br />
7. Epiphytes- air plants; no roots in the soil<br />
Soil protozoa – amoeba, ciliates, flagellates</li></li></ul><li>Soil Subsystem<br />Three size groups<br />1. Microbiota – includes soil algae, the bacteria, fungi, and protozoa.<br />2.Mesobiota – detritus-bacterial feeders includes the nematodes, the small oligochaete worms, smaller insect larvae, and microarthropods<br />3. Macrobiota- includes roots of plants, larger insects, earthworms, and other organisms can be assorted by hand.<br />
Soil Respiration<br />3 methods todetemine total soil metabolism<br />Difference Method – subtracting the energy consumed by above-ground herbivores from net primary production<br />Litter fall method – determining the amount and energy value of the detritus (litter) input into the soil subsystem<br />Direct measurement of CO2<br />
Vegetation Subsystem<br /><ul><li>Phytosociology-quantitave study of the structure of vegetation, which aims to describe vegetation, explain its pattern, and classify it in a meaningful way.
Constancy-percent of plots containing the species
Fidelity – degree of constriction of a species to a particulat situation</li></li></ul><li>Root/Shoot Ratio<br />The proportion of producer biomass, production or nutrients below and above the ground.<br />The effect of Temperature on Root/Shoot Ratios in crops grown under optimal mineral and water conditions.<br />After Van Doblen, 1962, given as shoot/root ratios converted to root/shoot ratios.<br />
Distribution of the Earth's Eight Major Terrestrial Biomes.<br />(Adapted from: H.J. de Blij and P.O. Miller. 1996. Physical Geography of the Global Environment. John Wiley, New York. Pp. 290.)<br />
Biomes<br /><ul><li>Complex biotic community characterized by </li></ul>distinctive plant and animal species and maintained under the climatic conditions of the region, especially such a community that has <br />developed to climax.<br /><ul><li>Terrestrial (land) biomes
Aquatic biomes (including Freshwater biomes and Marine biomes)</li></li></ul><li>
Tundra<br /><ul><li>‘tundra' from a Finnish word tunturi, meaning treeless plains
vegetation mainly comprises of dwarf shrubs, grass, moss and lichen
prominent animals are polar bears, arctic fox, grizzly bear, Harlequin duck, musk ox, caribou and snow owls</li></li></ul><li>Northern Coniferous Forest<br /><ul><li>occupies a vast area below the tundra, extending completely across Canada and into interior Alaska.