ESRM 101 Final Quiz

ESRM 101 Final Quiz Historically what has been the typical response of people to any natural disturbance? By ignoring major disturbances that occur over longer time scales, how was land management for timber, conservation and endangered species management impacted? Realistically, can humans manage large scale natural disturbances? - Historically the response has been to try and control or mitigate the effects of natural disturbance. Land management is impacted positively when ignoring major disturbances as they are beneficial for the environment. Humans cannot realistically manage large scale natural disturbances. Why care about natural disturbances? - Impacts landscapes planning efforts, management of protected areas, and endangered species management Why can disturbances be defined as being either GOOD, BAD or UGLY? How does each type of disturbance impact the environment and societies? Why do some disturbances maintain the health of our environments? - Disturbances can be good because some habitat areas need disturbances (ex. fire for prairies) to exist. Disturbances can be bad because can be caused by humans and lead to societal collapse - due to droughts, too much rain, bad land use (Deforestation), and economic decisions. Prior to the 1960s, forests fires were considered to be ecologically bad for the environment so the focus was on fire suppression and control. Today, we recognize the importance of fire in ecosystems. What knowledge changed our view of fires? Which tree species was responsible for these changed views and what is the relationship of this tree to fire? Why do some animals need fire to survive? - The lodgepole pine tree was responsible for changing our view of fires- it is highly flammable, and causes large scale fires when trees are over 100 years old, burning up its competitors and exposing bare ground to germinate new seeds (have serotinous cones that open after fire) What are the environmental and ecological repercussions of the loss of fires in prairies in North America? Who loses and who wins when prairies cease to exist? Today, what is the major reason explaining the loss of prairies? - The loss of prairies is an unexpected consequence of fire control- loss of prairies by forests encroaching into meadows. Fire keeps forests out. Fire control lets forests out compete and encroach into meadows. When you allow fires to burn there will be no trees in prairie. Many Native American root crops collected in prairies, introducing fire to get prairies back. Farmers/ranchers win because do not have to deal w prairie dogs eating crops or fires burning crops or houses. Animals that depend on prairie dogs lose (black-footed ferret extinct because not enough prairie dogs) Why is it realistic to call humans 'disturbance agents' in ecosystems [Answer according to the class lecture]? What is a common human management activity that starts the collapse of a civilization [It is not the tipping point]? What factor finally pushes a civilization to collapse? - It is realistic to call them disturbance agents because of what they do and how they alter the landscape (making the land less resilient to disturbances in some cases). A common human management activity that starts the collapse of a civilization is deforestation? The Nazca people in Peru collapsed despite their construction of an elaborate aqueduct system to collect ground water to farm. What series of activities started the process causing their collapse? What was the final trigger explaining this collapse? What was the forest link to the collapse of the Nazca people? - Extreme weather event (El nino) caused tipping point following bad land-use decisions = collapse. Deforestation and occurrence of extreme el nino event resulted in heavy floods- which caused loss of surface irrigation systems used to grow crops- which led to dry winds of desert blowing away soil. Final trigger was bad land-use decisions. FORESTS PROTECTED against extreme climatic events. acid rain - any form of precipitation or rain with high levels of nitric and sulfuric acids. It can occur in form of snow, fog, and tiny bits of dry material that settle to Earth. Most acid rain caused by human activities. Biggest producer of