More Ecosystems Red Spruce – Fraser Fir Forest in the Appalachian Mountains of North Carolina Grassland on rolling hills in North Dakota Mid-montane conifer forest, Yosemite National Park, CA, about 2,000 m in elevation.

Biomes Biomes are groupings of similar ecosystems or landscapes. Biomes are at a much larger scale.

Our text uses “Major Vegetation Types of North America.” These terms are used for biomes as well.

Ecological Succession Ecosystems are dynamic systems always changing. This section deals with the changing of vegetation communities or ecosystems through time. Ecological Succession - Biotic communities giving way to other biotic communities. - The Ecosystem is changing during succession. - Changing conditions pave the way for other species. - Pioneer species start Ecological Succession. Note: Humans can put back succession and manage for certain successional stages. - Climax Ecosystem – The last stage in ecological succession. This is an ecosystem in which populations of all organisms are in balance with each other and with all existing abiotic factors. A climax ecosystem can change sometimes if climate changes or the introduction of introduced species.

Bare Rock Moss Weeds Annual Grasses Perennial Grasses Shrubs Coniferous Trees (Pines) Hardwood Trees (Oak-Hickory) Hardwood Trees (Beech-Maple) Primary Succession – Occurs when an area has not been previously occupied. This starts with bare rock. Examples: Bare rock exposed by retreating glaciers, earthquakes, landslides, and volcanic eruptions. Primary Succession on Bare Rock. (Moss invades bare rock and acts as a collector, accumulating a layer of soil sufficient for additional plants to become established.) Bare rock gives way to moss. Moss gives way to weeds. Weeds give way to annual grass, etc. The ecosystem is changing.

Secondary Succession – Starts with preexisting soil. This is when a biotic community is reinvading or an ecosystem succession is set back. Examples: Abandoned agriculture fields slowly succeed to deciduous forests. Secondary Succession Grass grows fast and is a good invader but is easily shaded out by other vegetation. Other vegetation changes the conditions and the conditions are no longer beneficial for grass. Abandoned Field Annual Grasses Perennial Grasses Shrubs Coniferous Trees (Pines) Hardwood Trees (Oak-Hickory) Hardwood Trees (Beech-Maple)

Introduced Species Introduced or Exotic Species are species from foreign ecosystems. They are brought to new ecosystems by people accidentally or on purpose. Introduced or Exotic is the opposite of native. A native species is originally found in the ecosystem of interest. Introduced species cost the USA 138 billion dollars a year. A Few Exotic Plants Found in North America: Tree-of- Heaven, Kudzu, Chinese Chestnut Introduced species can be problematic because they have no natural predators or parasites in the newly invaded ecosystem. When introduced or exotic species numbers greatly increase, they are termed invasive or invasive exotics. Invasive exotics can greatly degrade ecosystems. How do you control invasive exotic plants? Encourage herbivores (if possible and those herbivore are native), herbicides, physical control such as cutting and pulling.

American Chestnut - The American Chestnut is native to Eastern North America. - The Chinese Chestnut originally from China and was brought to Eastern North America in the early 1900s. The Chinese Chestnut carried a disease (a fungal blight) which decimated the American chestnut population. Chinese Chestnut

Historic Range of American Chestnut By 1950, the fungal blight killed nearly every living American chestnut tree. However, there is hope of bringing the American Chestnut back by using biotechnology techniques. American Chestnut

Conservation Biology Conservation Biology is a relatively new science that studies the impact of human societies on the nonhuman landscape. Conservation biology is interested in conserving genetic diversity, species diversity and ecosystem diversity. When studying conservation biology, endangered species, minimum populations, human sustainable development, land management and ecosystem restoration, are important topics. Ecosystem Restoration – the process of modifying the environment and the vegetation of an ecosystem that has been degraded by human-caused disturbances. Ecosystem restoration strives to return that degraded ecosystem to its pre-disturbed state.

Paired photographs taken before and after 64 years of fire- suppression management near Ebbetts Pass in the Sierra Nevada of California. Thinning, followed by prescribed fire, has restored a similar forest back to a condition that resembles the natural vegetation Today Ecosystem Restoration in Action

BIO 141 Botany with Laboratory This product is sponsored by a grant awarded under the President’s Community-Based Job Training Grants as implemented by the U.S. Department of Labor’s Employment and Training Administration. The information contained in this product was created by a grantee organization and does not necessarily reflect the official position of the U.S. Department of Labor. All references to non-governmental companies or organizations, their services, products, or resources are offered for informational purposes and should not be construed as an endorsement by the Department of Labor. This product is copyrighted by the institution that created it and is intended for individual organizational, non-commercial use only.