Weeds The Cancer of Our Land

Why Care? “The spread of noxious weeds may signal the decline of entire ecological watersheds. They severely impact the beauty and biodiversity of natural areas and cause widespread economic losses. Weeds are problems for urban as well as rural areas, and for private, state, and federal lands. Noxious weed species spare no segment of society—rancher, fisher, and cycler alike—and when unmanaged, they spread rapidly, unceasingly, and silently. Noxious weeds pose a serious threat to all Idahoans and to the land we call home.” Patrick A.Takasugi, Director Idaho Department of Agriculture

Why Care? Several scientists who focus on the ecological effects of global change consider invasive species the most serious threat, more serious than global warming or ozone depletion. While global warming and ozone depletion have serious implications, they are reversible. Once a noxious weed species is widely distributed it is virtually impossible to remove it, making their effect on the environment permanent.

What is a Native Species? Native/Indigenous: occurs in a particular place without the help of humans Home range is influenced by:  Climate  Soils  Topography  Hydrology  Biological interactions  Natural Dispersal

What is an Exotic or Non-native Species? Exotic: An organism occurring outside of its natural home range. Other names include alien, foreign, non- indigenous Introduced by humans

How did Non-Native Species Get Here? Humans introduced non-native plants as:  Grains and food crops  Seeds in Ship Ballast  Ornamentals  Plants for erosion control  Plants with higher forage value  Accidental Introductions of exotics continues today!!

What is an Invasive Species? Invasive species: An organism that spreads and establishes over large areas and persists Invasive Species Website =

When is a Guest a Pest? Invasive Species are: Often non-native (or alien) to the ecosystem  Important! Not all non-natives are invasive! Have growth characteristics that will allow it to dominate the ecosystem Whose introduction causes or is likely to cause economic or environmental harm or harm to human health.

Characteristics of Invasive Plants Abundant seed producers Rapid population establishment Long-term survival of seeds Occupy disturbed sites Competitive Lack of natural enemies

How Bad are Invasive Species? Impact native plants, animals, and natural ecosystems by:  Reducing biological diversity  Altering hydrologic conditions  Altering soil characteristics  Altering fire intensity and frequency  Interfering with natural sucession  Competing for native pollinators  Replacing complex communities with monocultures  Displacing rare plant species

Noxious = plant species that have been designated “noxious” by law. The word “noxious” simply means deleterious Weeds are declared noxious by states or counties. In Idaho, hundreds of weed species exist. However, only 36 are designated noxious by Idaho law. What are Noxious Weeds?

Weed Management Maintain healthy natural plant communities

Weed Management Prevention  Consider vectors of introduction  Develop plans to minimize introduction  Minimize disturbances that may favor weeds Early Detection  Develop strategy for early detection  Eradicate when possible

Weed Management Weed Survey  Collect information about weed biology and ecology.  Document growth requirements  Identify sites susceptible to invasion  Evaluate progress of weed management plan

Weed Mapping  Delineate extent  Document control activities  Monitor spread over time Weed Management

Integrated Weed Management Weed Control Grazing Chemical Biocontrol

Integrated Weed Management: Example in Idaho Yellow starthistle control in Hells Canyon courtesy of Idaho Weed Awareness Campaign Click to play video

Integrated Weed Management Video Followup  What types of control are they implementing? Chemical, biological (bugs)  What is their management goal or conservation target? To maintain good native bunchgrass communities  What are some challenges to control? Terrain, degree of infestation

Weed Management Coordinated Weed Management Groups  Develop plans across land ownerships  Leverage resources Time Equipment Money Expertise  Apply for state and federal funds Click to play video Video Courtesy of Idaho Weed Awareness Campaign

Weed Management Monitoring and Evaluation  Was weed population adequately suppressed?  Was cost of suppression acceptable?  What were non-target effects?  Should treatment be repeated or modified?  Were land management goals met?

Its not only about the Weed Its about the Land