User:Lopezca/sandbox

Definitions
Non-native/invasive species, are classified as a species that are introduced beyond their native range through, direct or indirect, human action and causes some sort of change in the ecosystem.


 * Invasive Species Definition : When the change in the ecosystem impacts native biota in a negative way, we consider this as an invasive species.


 * Non-Native Species Definition : If the change in the ecosystem is stays neutral or has beneficial impacts to native biota, this species is labeled as non-native.

Non-Native Species Establishment
For a species to become established in a place where it is not commonly found, it must pass through stages of invasion and survive. There are four stages that a species must overcome that include:

1) The Transport Stage- in this stage the species must have the ability to travel across geographic barriers to a new range.

2) The Colonization Stage- the species must be able to survive the new range and be able to tolerate the different environmental conditions it is presented with.

3) The Establishment Stage- this stage requires the species to acquire necessary resources, survive interactions with other species and in some instances form mutualistic relationships at the new site.

4) The Landscape Spread Stage- within the last stage, the species must spread within the new site to create a viable population in order to continually spread throughout the landscape in different locations.

Invasive Species Impacts
Ways that invasive plant species can have negative effects on ecosystems, directly and indirectly, are through impacts on habitat structure, biodiversity, productivity, nutrient cycling, microorganisms, and food webs. Invasive species are difficult to deal with due to the mechanisms by which invasive species displace native species. These mechanisms are is either difficult to determine or are rarely tested. With the constant increase in anthropocentric changes to land use for homes, commerce, recreation and waste, we also see an increase in nutrient load, sediment load, altered hydrology and modified physical environments. These changes in the environment put a stress on the native biota, while giving invasive species an opportunity to invade and take over an area. Freshwater ecosystems are highly vulnerable to the invasion of invasive species due to their high degree of isolation and endemism.

The impacts of invasive species on ecosystems is ongoing and will continue to grow over time with more research. There is speculation on the actual impacts that non-native species have on the environment. This is due the small amount of studies that actually quantitively evaluate non-native species impacts on ecosystems. There is also the argument that the effects that non-native species have on an ecosystem can vary depending on seasonality and habitat type.

Introduction Methods of Aquatic Plants
Human interactions play a large role in the movement of invasive aquatic plants all over the globe. Common ways humans inadvertently introduce invasive aquatic species is through methods of water gardening, wetland restoration, lake restoration and aquarium construction. Other methods include horticulture methods, cultivated plants, and escapees from greenhouse.

Prevention/Early Detection
Prevention and early detection of invasive species is the most efficient and cost-effective method of managing impacts. Using risk analysis and predicting a species possible future distribution is key for implementing monitoring and management actions. Understanding how invasive species spread, their potential ecological impacts, and the best practice methodology for controlling them can help with the reduction of invasive species at a national, regional and local level. There are an abundance of natural areas that have a high number of invasive species that natural resource managers are tasked with controlling. Having proper management actions to set priorities for the control and prevention of invasive species is how to maximize protections of native systems.

Invasive Species Distribution
A species that is considered a native species in one country or region may be considered non-native or invasive in another country or region.


 * For example, Purple Loosestrife is native to Europe, Asia, northwest Africa, and southeast Australia, but has sense invaded the United States and has been labeled an invasive species due to the negative impacts this species has made on ecosystems.

United States (Midwest Region)
Just a few broad examples of aquatic invasive species within the Midwest United States that are thought to have negative impacts on ecosystems include: Phragmites, Purple Loosestrife, and Flowering Rush. These problems can range from reducing the ability of streams to deliver water to places they historically would, displacing native species, causing localized flooding in certain areas, altering habitat, and increasing streamflow evapotranspiration.