Biomes FIELD BIOLOGY & METHODOLOGY Fall 2014 Althoff Lecture 04

Biomes “______ units” (i.e., not political boundaries) Defined: the major terrestrial unit of vegetation with the fundamental characteristic being the “__________” of the plants dominating it.

Form vs. Species Biome classifications based on _____________ (i.e., grasses, deciduous trees, conifers, etc.) rather than ________ (red maple, sugar maple, red pine, white pine, etc.) Similar “forms” found in _________ regions of the world

Growth Forms Plants with ___________ (adaptations) that enable them to dominant the local landscape once established.

Growth forms…con’t Grasses establish _________systems and withstand conditions better in Great Plains than trees. And, they recover from fires quicker—a common natural disturbance for prairies Trees, when established, out compete grasses in Northeast because fewer fires and more annual rainfall… ___________ grasses

What role does climate play? Biomes ARE PREDOMINATELY influenced by ___________ & ________________ patterns = CLIMATE

__ Major ______ – according to Whittaker Tropical rain forest Tropical seasonal forest Subtropical desert Woodland/shrubland Temperate rain forest Temperate grassland/desert Grassland (shrubland) Boreal forest Tundra

Whittaker’s Classification Based on a) annual precipitation b) average temperature KNOW Ricklef’s biomes ( handout )… be able to label 9 biomes according to precipitation & temperature

Whittaker vs. Walter (handout) Each has “9” zones/divisions Both based on precip & temp More refined view: zones defined mostly by the conditions of moisture & cold stress Whittaker = veg zones vs. Walter = climate zones

Other factors influence composition of plant communities Topography Soils Fire Seasonal variation in climate _______________

Topography, Soils & Local Distribution Back to physical factors... Understand relationships expressed in handout (Beals & Cope) that highlights: forest floor plant distribution relative to ____ and _____________ content

% organic matter % calcium Occurrence of four forest floor Plant species with respect to calcium and organic matter content of soil in woodlands of eastern Indiana Beals, E.W. and J.B. Cope Ecology 45:

_________ Factors Conditions in the soil: nutrient status, water availability, toxic mineral content. Distribution of plants on and adjacent to campus a good example

Concept of SPECIALIZATION Adaptations that enable organisms to survive (thrive) in a particular, restricted range of environmental conditions Examples: a) Sages: Table 5.1 (handout; Ricklefs1996) b) Oak leaves: Fig. 5.7 (next slide; Ricklefs1996)

Figure 5.7 (Ricklefs 1996) Silhouettes of a sun leaf and a shade leaf of white oak. The sun leaves have more edge per unit of surface area and therefore dissipate heat more rapidly SUN LEAF SHADE LEAF

Biomes in Aquatic Systems??? Does ____ “match” as well since biomes in terrestrial system based on vegetation growth forms…therefore not used in same way Aquatic biomes based on salinity, water movement, depth...

Aquatic Environments Fluvial systems Lakes Estuaries Oceans

Fluvial Systems “River systems” distinguished by the materials (plants & animals & other materials) continually moving downstream by currents

Lakes Any kind of depression, usually a product of _________ glaciation. Three zones: littoral, limnetic, benthic

Littoral zone Limnetic zone Benthic zone

Estuaries Special environments found at the mouths of rivers influenced by enclosed landforms or barrier islands. Unique because of “mix” of fresh and salt water.

Oceans Understood! However, must recognize tremendous ___________ in temp, depth, current, substrate, and tides. _________ “biome” on surface of the the earth

In Summary…. Geographic distribution of plants on _________________ scales determined primarily by climate… …but by topographic and soils on a ____ basis Climate profoundly affects evolution of plants and animals…which results in specializations to deal with the physical environment Plant growth forms directly relate to climate…so major types of vegetation match temperature and precipitation  allows for _____________ to be classified into biomes

In Summary….con’t Characteristics of biomes are further “influenced” by soil, climatic seasonality, fire, and grazing. ___ major approaches to ______ classification: Walter  climate zones Whittaker  vegetation zones Aquatic systems are not classified (typically) as biomes because they ____ the equivalent of terrestrial vegetation. But we can distinguish among streams, lakes, estuaries, and oceans