Ecology Project

Ecosystems of the World ProjectName:

The principles of ecology operate in every corner of the natural world, and we can learn a lot by considering areas different from our own. Each student will be assigned a unique natural place within a biome. Your task is to prepare a class presentation on your area, identifying the biome to which it belongs, the abiotic factors that characterize your location, and how the organisms that inhabit it are adapted for survival.

  • Whatever format you choose for your presentation, you must hand in cited research notes with a bibliography of at least three sources. The notes must be handwritten.
  • Each section of your notes should identify the source used (parenthetical citations are easiest).
  • Some students will be given responsibility for an introduction to the characteristics of each biome-- include map of where biome is located, relevant pictures, diagrams, climate data, geography, and importance to life on earth

Assessment Individual grade- 60 pts

Goals
Notes (20) /
  • Several pages of handwritten notes record project research
  • Facts about the general biome or specific site are researched in depth and illustrated with examples. Include:
  • climate conditions
  • soils
  • dominant vegetation
  • significant organisms and their niches
  • adaptations of organisms to conditions
  • environmental concerns and human effects on biome or site

Documentation (10) /
  • Each section of notes is cited with reference to bibliography
  • Typed bibliography of at least three sources is done according to library handout

Presentation (15) /
  • Written materials, including Power Point slides,are mostly or entirely accurate in GUM and spelling. Materials are neat, attractive, readable, and well-organized. Presentation is crisp, rehearsed, and accurate.

Quiz Questions (5) /
  • On the other side of this sheet write five possible quiz questions (with answers) based on your presentation,. Be sure to cover them in your presentation. These should require understanding and some critical thinking beyond simple factual information.

There will be an open notebook quiz on the presentations

Background Reading:

Biomes of the World

Paulson, Dennis.

Biomes (bioclimatic zones) are appropriate divisions by which to organize the natural world, because the organisms that live in each of them possess common constellations of adaptations to them, in particular to the climate of each of the zones and to the characteristic vegetation types that develop in them. The primary elements to be dealt with under each zone were chosen because they are considered the basic elements at all levels, from the entire planet through each of its component physical environments to the species themselves.

The climate must be understood as perhaps the most important element in determining what kinds of organisms can live in an area and how they are modified to live under different conditions of temperature and precipitation and the seasonal distribution of these factors. Again, each spot on Earth has its own climate, influenced by both the macroclimate of the region and the microclimate of the particular site. But there are climatic commonalities on a grand scale that cause, for example, unrelated animals in the Sahara and Sonoran Deserts to have surprisingly much in common.

Soils are very important because they influence the types of plants (and thus plant communities) that will grow within a particular bioclimatic zone, and as substrates to animals as well. And soils in turn are much influenced by regional climates, as well as parent-rock geology.

The vegetation of an area is dependent on climate and soils and, in turn, influences very greatly both the plant and the animal species that can exist in a location. Vegetation varies in size and structure (physiognomy), in its seasonal manifestation, and in how it changes over time. Its importance is greater than the sum of its individual plant parts, as many species of animals, for example, are influenced greatly by the physical structure of the plant community, still others by the actual species of plants present.

A major component of the plants and animals in a region is their overall diversity, indicative of how many species can coexist there. This varies substantially both among and within bioclimatic zones, dependent on both climate and vegetation. In more diverse communities the degree and types of interactions among plants and animals are increased, with an increase in the number and complexity of stories to be told.

Plant and animal adaptations are the physical manifestations of organic evolution. Each individual is a collection of adaptations that allow it to function effectively in its environment, and these adaptations characterize the species to which it belongs. They are affected by all aspects of the environment, both physical (climate, water, substrate) and biological (other species as prey, predators, parasites, competitors or symbionts). Each species is unique, yet it shares particular types of adaptations with many other species. The generalities that can be expressed about these adaptations, if effectively presented, should reside in the brain as the conceptual file folders within which the individual species fact sheets can be stored.

Finally, as humans are significant in the world far out of proportion to being only one of millions of species in it, an interpretive element dealing with human effects seems necessary. No part of the world is unaffected by our presence, and we have the ability to modify environments on a massive scale. Our effects, which began in small ways millions of years ago and grew in proportion to the growth of the human population, can be considered positive or negative, depending on perspective.

Most basic principles of biology can be illustrated in the context of these elements, but those that are based on relationships among two or more species do not always clearly fall within features of the environment such as climate and soils or adaptations of individual species. These principles include the broad category of trophic relationships (food webs, productivity, decomposition, nutrient cycles) and interactions such as predator-prey relationships, competition, and symbiosis.

Characteristics Of World Bioclimatic Zones

CLIMATE. There is a temperature gradient from the equator to the poles because of the earth's orientation toward sun. The rotation of the earth and the inertia of the air above it causes westerly winds at the equator. The Coriolis force deflects winds to the right in the northern hemisphere and to the left in the southern hemisphere, causing wind gyres. Equatorial air rises and, deflected, falls back to the surface in temperate latitudes, where it then flows toward the east. Wind patterns produce major ocean currents revolving counter-clockwise in the northern hemisphere and clockwise in the southern hemisphere in each ocean basin. Current gyres carry cold water toward the equator on east sides of the oceans, warm water to higher latitudes on the west sides. The temperature of water bodies affects nearby land masses greatly, although there is less effect with distance from water. Land masses and underwater topography deflect currents into complex patterns near the continents. These in turn cause upwellings, which affect productivity and thus diversity and abundance of marine organisms, including those such as birds and pinnipeds that are based on land.

The wind blows water vapor from the ocean to the land. If the land is hotter, it evaporates; if cooler, it falls as precipitation. As the air ascends and cools, it loses its capacity to hold water (adiabatic cooling). Thus in hot weather thermals rise, and water condenses and falls as showers; also precipitation increases up mountainsides. Mountains serve as barriers to water vapor, causing rain shadows on their leeward sides. The tilting of the earth, with accompanying migration of the thermal equator, causes seasonal changes of wind direction responsible for the seasonality of precipitation patterns in the tropics; precipitation is also affected by the seasons in temperate latitudes.

SOILS. Parent rock erodes physically and chemically into smaller and smaller particles, which become soils as they collect on both coarse and fine scales; the chemical nature of soil reflects the nature of its parent rock. Particles are further sorted by size when deposited by water and wind. Soils are classified by the size of the particles that make them up, from the finest (clay) through increasingly coarse (silt, sand) to the coarsest (gravel), and by organic content (humus). Loam is soil that is well mixed with sands, silts and clays. Soils form horizons, layers that are distinct from one another chemically and physically because of their distance from the surface (which in turn controls the amount of water and organic material present). The overall direction of water movement (up or down) through soil is of some importance in determining its structure. The water-holding capacity of soil is related to the soil type, with the finest soils holding water and coarser ones allowing it to percolate through. The value of soil to plants is related to its water-holding capacity, physical nature (what mixture of sand, silt and clay particles), and chemical content; both inorganic minerals and organic humus are important.

VEGETATION. Vegetation patterns are responsive to the interaction of temperature (latitudinal and altitudinal gradients) and precipitation (more complex, often longitudinal gradients because of the east-west tendency of the winds, as well as well-defined latitudinal ones) patterns. The degree of seasonality also has a major effect. The earth's surface is forested with trees except where too cold, too dry, or too wet. Herbaceous vegetation is dominant nearer extremes, with no vegetation at all at the coldest and driest extremes.

Vegetation is the sum of its parts, the parts being individual plants of individual species, and the species present and their relative proportions are important descriptive components of it. Descriptions of vegetation take into account plant species and their abundance and size distribution, life forms (trees, shrubs, herbs, bryoids, epiphytes, lianas), seasonal functions (evergreen vs. deciduous), and leaf shapes, sizes, and textures.

DIVERSITY. There are two major components of diversity: within-habitat (diversity may vary greatly between two forest types, for example) and between-habitat (this covers diversity for an entire area, thus also dependent on the diversity of habitats present). Within-habitat diversity is highest in forests of the equatorial lowlands, and lower with increased latitude, altitude, seasonal variation in climate, simplicity of vegetation, and any environmental extreme, to very low near poles and on high mountains. There are similar latitudinal gradients in fresh and salt water, also decreased aquatic diversity with depth and chemical extremes. There is also lowered diversity on peninsulas and islands because of problems of historical access.

PLANT ADAPTATIONS. The basic needs of plants are homeostasis, space, food, predator avoidance, and reproduction. There is no locomotion, thus plants are subject to vicissitudes of the environment, so they are often narrowly restricted to particular combinations of temperature, humidity, salinity, soil water, and chemistry (where homeostasis is thus assured). Plants need space for branches and stems for support of light-gathering, photosynthetic, and respiratory leaves; elaboration of woody tissue provides greater support for big plants. They also need space underground for roots for gas and chemical exchange with the substrate, and for nutrient and water gathering. Competition for space is intense among plants, at leaf and root level. Plant nutrition comes from a combination of leaf photosynthesis and root gathering. Predator avoidance is by physical (spines, hairs, sticky resins) and/or chemical means (there is an almost infinite number of chemicals in plants that lower their palatability to animals) or even by rarity of the plant, its flowers or fruits.

Reproduction is by flowers and fruits. As locomotion is lacking, reproduction depends on other features of the environment--wind, water, or animal pollination and seed dispersal. Animals are often important for dispersal of pollen and seeds. Reproductive structures vary widely: inflorescence type, flower sizes, shapes and colors; infructescence type, fruit sizes, shapes and colors; seed sizes and numbers. Most of these are clearly correlated with the mode of pollination/seed dispersal.

ANIMAL ADAPTATIONS. Animal basic needs include homeostasis, space, refuge, food, predator avoidance, and reproduction. Homeostasis needs lead to occurrence only in restricted range of temperature, humidity, salinity, oxygen level, and other features that affect the animal's internal environment. There is great variation in tolerance to environmental extremes, maximal in endothermal birds and mammals. Land and water are two basic environments, and many animals move between them or secondarily into air for relatively brief periods. Locomotion is significant in animals (lacking in plants for most part) to allow these movements, also movement about home range and long-distance movements that may be for dispersal or may involve seasonal back-and-forth migration. Some major groups of animals are sessile (fixed in place) and like plants move only in certain life-history stages. Space needs lead to fixed or dynamic home ranges, which are defended in some sessile or territorial motile animals. The size of the home range or territory may change seasonally or be different in different age/sex classes. Refuges are needed for hiding from predators, sleeping, storing food, and having and rearing young.

Food sources are plants (herbivores) or other animals (carnivores), and diets vary from very generalized to very specialized. Many animals are omnivores (plant and animal diets). Herbivores specialize on leaves, seeds, fruits or nectar, with different arrays of adaptations for each type. Leaves are easy to capture but difficult to digest, so leaf-eaters have special adaptations to process cellulose and antiherbivore compounds. Seeds are locally and seasonally abundant, and are often stored by caching for leaner periods. Special adaptations (rodent teeth, finch bill) are needed to crack seed coat. Color vision is an important adaptation to locate flowers and fruits for both nectar- and fruit-eating, with much coevolutionary fine tuning for these pollinating and seed-dispersing interactions. There are just as many specialized sets of adaptations for carnivory, including those for finding and capturing plankton, mollusks, worms, termites, butterflies, fish, snakes, birds, and other morphologically distinctive taxonomic groups, even carrion. Memory and intelligence are characteristic components of some of these predator adaptations, but there are many other special attributes, such as the use of tools or venom.

There are many predator-avoidance adaptations, including hiding out of sight or in sight (camouflage); escaping by speed or stealth or immersion in a group; fighting or threat with weapons (teeth, horns); physical protection such as spines or shells; chemical protection such as unpalatability or poisonous bite or sting; and mimicry of unpalatable/dangerous animals. There is a wide variation in reproductive strategies: clutch size, size of offspring at birth, eggs vs. live birth, and degree of parental care.

Most types of adaptations are clearly attributable to one of these basic needs. For example, coloration may be an adaptation for species recognition (need for conspecific territory defenders to recognize each other involves space; need for mates to recognize one another involves reproduction), to look like the environment (camouflage for predator avoidance) or like some other animal (mimicry for predator avoidance) or to warn of its dangerousness (aposematic coloration for predator avoidance) or to increase or decrease heat load by absorbing or reflecting sunlight (homeostasis).

HUMAN EFFECTS. Those that are negative to the environment include habitat destruction, chemical pollution, predator/parasite introduction, competitor introduction, and active persecution for food, skin, sport, etc. Those that are positive to the environment include conservation by habitat preservation and captive breeding. Those that are positive to humans and may or may not be harmful to the environment include animal domestication and horticulture

How to cite this source:

Paulson, Dennison. “Biomes of the World.” University of Puget Sound. 20 Feb. 2002.

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Biomes ReadingStudy GuideName:Block:

  1. Why do unrelated animals in deserts on different continents have characteristics in common?
  1. How does the geology of bedrock affect what plant communities are present?
  1. Give an example of how the physical structure of a plant community could influence animals.
  1. Why is diversity of species an important biome characteristic?
  1. How do ocean currents affect biomes?
  1. What happens when moist air rises?
  1. How are soil particles sorted by size?
  1. Why is the diversity of species less on islands?
  1. For what condition do plants strongly compete?
  1. What are some ways in which plants overcome their stationary state through reproduction strategies?
  1. How do animals deal with their need for space?
  1. What human activities do you think have large effects on particular biomes?

BonusDefine the following