If you were to hike up a mountain, the changes you would see in the vegetation would parallel those as you move to higher latitudes. Ecologists who study biogeography examine patterns of species distribution.
No species exists everywhere; for example, the Venus flytrap is endemic to a small area in North and South Carolina. An endemic species is one which is naturally found only in a specific geographic area that is usually restricted in size. Other species are generalists: species which live in a wide variety of geographic areas; the raccoon, for example, is native to most of North and Central America. Species distribution patterns are based on biotic and abiotic factors and their influences during the very long periods of time required for species evolution; therefore, early studies of biogeography were closely linked to the emergence of evolutionary thinking in the eighteenth century.
Some of the most distinctive assemblages of plants and animals occur in regions that have been physically separated for millions of years by geographic barriers. Biologists estimate that Australia, for example, has between , and , species of plants and animals.
Figure 1. Australia is home to many endemic species. The a wallaby Wallabia bicolor , a medium-sized member of the kangaroo family, is a pouched mammal, or marsupial. The b echidna Tachyglossus aculeatus is an egg-laying mammal. Sometimes ecologists discover unique patterns of species distribution by determining where species are not found.
Hawaii, for example, has no native land species of reptiles or amphibians, and has only one native terrestrial mammal, the hoary bat. Most of New Guinea, as another example, lacks placental mammals. Check out this video to observe a platypus swimming in its natural habitat in New South Wales, Australia.
Note that this video has no narration. Plants can be endemic or generalists: endemic plants are found only on specific regions of the Earth, while generalists are found on many regions.
Isolated land masses—such as Australia, Hawaii, and Madagascar—often have large numbers of endemic plant species. Some of these plants are endangered due to human activity. The forest gardenia Gardenia brighamii , for instance, is endemic to Hawaii; only an estimated 15—20 trees are thought to exist. Figure 2. The spring beauty is an ephemeral spring plant that flowers early in the spring to avoid competing with larger forest trees for sunlight. Energy from the sun is captured by green plants, algae, cyanobacteria, and photosynthetic protists.
These organisms convert solar energy into the chemical energy needed by all living things. Light availability can be an important force directly affecting the evolution of adaptations in photosynthesizers. For instance, plants in the understory of a temperate forest are shaded when the trees above them in the canopy completely leaf out in the late spring.
Not surprisingly, understory plants have adaptations to successfully capture available light. One such adaptation is the rapid growth of spring ephemeral plants such as the spring beauty Figure 2. These spring flowers achieve much of their growth and finish their life cycle reproduce early in the season before the trees in the canopy develop leaves. In aquatic ecosystems, the availability of light may be limited because sunlight is absorbed by water, plants, suspended particles, and resident microorganisms.
Toward the bottom of a lake, pond, or ocean, there is a zone that light cannot reach. Photosynthesis cannot take place there and, as a result, a number of adaptations have evolved that enable living things to survive without light. For instance, aquatic plants have photosynthetic tissue near the surface of the water; for example, think of the broad, floating leaves of a water lily—water lilies cannot survive without light.
In environments such as hydrothermal vents, some bacteria extract energy from inorganic chemicals because there is no light for photosynthesis. Figure 3. Ocean upwelling is an important process that recycles nutrients and energy in the ocean. As wind green arrows pushes offshore, it causes water from the ocean bottom red arrows to move to the surface, bringing up nutrients from the ocean depths. An abiotic factor is a non-living part of an ecosystem that shapes its environment.
In a terrestrial ecosystem, examples might include temperature, light, and water. In a marine ecosystem, abiotic factors would include salinity and ocean currents. Abiotic and biotic factors work together to create a unique ecosystem. Learn more about abiotic factors with this curated resource collection.
Students define and provide examples of abiotic and biotic factors of different ecosystems. Then they investigate the importance of abiotic factors and physical processes within ocean ecosystems. The oriental whip snake Ahaetulla prasina is a common snake found throughout parts of Asia.
Join our community of educators and receive the latest information on National Geographic's resources for you and your students. Skip to content. Image Sidewinder in Desert Species are not only adapted other living things within their ecosystems but also to the abiotic factors—nonliving physical and chemical aspects—in their environments.
Photograph from age fotostock. Twitter Facebook Pinterest Google Classroom. Encyclopedic Entry Vocabulary. Media Credits The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit.
Media If a media asset is downloadable, a download button appears in the corner of the media viewer. Cathel Hutchison began editing and writing in and has worked with various institutions and publishers, including editing courses for the Open University and captioning for the cultural archive "Am Baile.
The Effect of Darkness on Photosynthesis. What Is the Role of Pigments in Photosynthesis? Two Nonliving Parts of an Ecosystem. What Are the Functions of Photosynthesis? How Long Does Photosynthesis Take? Roles of Cyanobacteria in the Ecosystem. How Does Eutrophication Affect pH? In general, organic matter organic carbon in the soil improves plant growth. A practical rule is to use all available crop residues leaves, stems, etc.
Minimizing erosion is another solution since erosion transports upper organic matter into other areas. Macro and micronutrients should be in optimum concentrations to support plant life in an area. When they are missing, you can see some problems in plants. How do abiotic factors affect biotic factors in an environment? Nov 2, So, the abiotic factors are controling the biotic factors of an environment.
0コメント