. In some areas, the barrier built to prevent uncontrolled movement of people across the border between the United States and Mexico consists of miles of 6-meter- tall steel beams placed four inches apart. Discuss the ecological effects of such a barrier. What types of organ- isms would be most adversely affected by this habitat fragmentation?

Explain the solution for the removal of water flies. How will this solution affect the native species, economy, and/or social impacts? How long do you think it will take to return to the original biodiversity of the ecosystem based on this solution and why?

In a survey of a stream bank in northeastern Ontario, a local naturalist group found that 20% of the plant cover was made up of purple loosetrife. Briefly describe two possible reasons for the presence of this invasive species on the stream bank

Many species of bacteria take up residence in our bodies and assist in digestion of certain foods. What type of interaction is this? A Competition Parasitism/Predation (c) Mutualism Commensalism

I’m having hard time understanding which is abiotic or biotic to this answer. Can you please help?

Lake Mendota is a lake with high levels of nutrient input from agriculture that has the potential to fuel blooms of phytoplankton. In 2009 the invasive spiny water flea Bythotrephes (native to Europe and Asia) was first detected in the lake. In the figure, the food web for Lake Mendota prior to the invasion is on the left, and after the invasion on the right. Bythotrephes is a more effective predator of the herbivorous zooplankton Daphnia than the native planktivorous perch (represented by the large red arrows between Bythotrephes and Daphnia), and perch consume Bythotrephes at much lower rates than they do Daphnia (represented by the small red arrows between perch and Bythotrephes). See attached image.  Part A In the food web prior to the invasion (1988-2008), what effect would increasing the abundance of pike have on the abundance of Daphnia? A) Increase B) Decrease C) Stay the same Part B What type of process or phenomenon describes the way that abundance of pike affects the…

Lake Mendota is a lake with high levels of nutrient input from agriculture that has the potential to fuel blooms of phytoplankton. In 2009 the invasive spiny water flea Bythotrephes (native to Europe and Asia) was first detected in the lake. In the figure, the food web for Lake Mendota prior to the invasion is on the left, and after the invasion on the right. Bythotrephes is a more effective predator of the herbivorous zooplankton Daphnia than the native planktivorous perch (represented by the large red arrows between Bythotrephes and Daphnia), and perch consume Bythotrephes at much lower rates than they do Daphnia (represented by the small red arrows between perch and Bythotrephes). See attached image Imagine that the lake was also contaminated with heavy metals. In which taxa would the concentration of heavy metals by highest? a) phytoplankton b) daphnia c) perch d) pike and why?

Reintroduction of species into their native ecosystem is a controversial topic. Provide at least 3 reasons in favor of this and 3 against the reintroduction of native species.

Lake Mendota is a lake with high levels of nutrient input from agriculture that has the potential to fuel blooms of phytoplankton. In 2009 the invasive spiny water flea Bythotrephes (native to Europe and Asia) was first detected in the lake. In the figure, the food web for Lake Mendota prior to the invasion is on the left, and after the invasion on the right. Bythotrephes is a more effective predator of the herbivorous zooplankton Daphnia than the native planktivorous perch (represented by the large red arrows between Bythotrephes and Daphnia), and perch consume Bythotrephes at much lower rates than they do Daphnia (represented by the small red arrows between perch and Bythotrephes). See attached image See second attached image for question

C. Legally protecting endangered species D. Regulating hunting and fishing 34. A wooded area has been divided by a housing development and is threatenin What term is used to describe this threat from human activities? A. habitat fragmentation B. acid precipitation C. habitat augmentation D. global warming 35. Which of the following is NOT a characteristic of an invasive species? A. They grow rapidly and outcompete with other plants or animals B. They produce large numbers of seeds/offspring at a young age C. They have very specific needs or requirements to survive 36. Which of the following was NOT a cascade effect from introducing wolv A. The change in the shape/path of the river B. The change in elk grazing areas C. Destruction of the Yellowstone ecosystem P. Reduction in the coyote population, increasing the raptor populat