Quiz 2 : Q & A Flashcards
- What are some agricultural practices at 21 Acres that are an improvement in environmental protection compared to analogous conventional agriculture practices. Briefly explain how each is an improvement over conventional methods.
- Cover crops on fields between production crops; fields are bare in conventional agriculture. Cover crops reduce soil loss and nutrient leaching and promote soil health. This reduces the need for added fertilizers used in conventional agriculture, which can lead to eutrophication and sedimentation of waterways.
- Use of compost or organic fertilizer that releases nutrients slowly, instead of synthetic fertilizers used in conventional agriculture. This reduces nutrient-rich runoff, which can lead to eutrophication and sedimentation of waterways.
- Use of biocontrol, crop rotation, and other non-toxic measures (e.g. catnip) to control pests instead of synthetic pesticides used in conventional agriculture. This eliminates the release of toxics associated with conventional agriculture, which can harm non-pest species (.e.g, beneficial insects).
We have heard that an important part of promoting environmentally sustainable agriculture is certification. Name one example of a legally certified standard in US agriculture.
USDA certified organic
Explain the importance of certification in making sustainable agriculture more widespread.
Often production costs of sustainably grown agricultural products are higher, at least initially, than conventionally grown. If farmers would sustain higher costs of production than in their current (conventional) practices, it is unlikely that sustainable farming could ever become widespread. To make sustainable farming attractive to producers (relative to conventional practices) there must be a mechanism for recovering greater income from the product, and certification, with enforceable legal standards and valid labeling, provides that mechanism. It also gives consumers the information and certainty necessary to make rational choices (so that market incentives lead to socially optimal outcomes).
According to Dr. Rob Turner, what are two likely sources of fecal coliform contamination of North Creek.
Sewer overflows
Crow roost
Failing septic tanks
Pet feces
Impervious surfaces do not themselves produce fecal coliform bacteria. Yet, in a talk about fecal coliform pollution, Dr. Rob Turner brought up the fact that 49% of North Creek watershed is covered by impervious surfaces. Explain the connection between impervious surfaces and fecal coliform pollution.
During rainstorms, impervious surfaces result in greater flow of water into storm drains, which carry storm water and sewage. This leads to sewer overflows, which results in sewage flowing overland into North Creek. Also, during storms, water washes across impervious surfaces (instead of soaking into the ground), picking up fecal coliform containing wastes (e.g., pet feces) and carrying them into the storm drains and into the creek.
How have humans altered the earth’s nitrogen cycle and what are two negative environmental effects that have resulted from human alteration of the nitrogen cycle.
Humans have doubled the flux of nitrogen from atmosphere to the earth’s biota (living organisms) through the Haber-Bosch process which converts atmospheric nitrogen to a form that is useable by plants. This has allowed the production of nitrogen fertilizers that have increased crop yields. Part credit given for other alterations such as fossil fuel burning and adding or removing nitrogen from different locations.
- Excess useable nitrogen flowing into water bodies has led to “dead zones” (hypoxia).
- Excess nitrogen from farm fields has caused nitrate pollution of ground water.
Currently, the single greated human-caused extinction threat to most endangered species is:
habitat loss
Of the choices below, which pair of ecosystems have the highest net primary productivity?
Open oceans and warm deserts Tropical forests and warm deserts Temperate wetlands and tropical forests Temperate forests and cool deserts Grasslands and temperate forests Tundra and cool deserts
Temperate wetlands and tropical forests
What are the four basic demographic variables that will determine a population’s growth rate?
Birth rate, Immigration rate, Death rate, Emigration rate
For a given habitat, the number of individuals in a population that can be supported by the available resources is called….
carrying capacity or K
Throughout most of human history, the Average Annual Growth Rate of the human population was….
much higher than at present
about the same as present
much lower than present
Much lower than present
What are the four components (types of footprints) that are added together to make the total ecological footprint that we calculated?
Carbon (Energy and CO2)
Food
Housing
Goods and Services
How would you rebuttle statement to, “Americans make up a tiny part of the world’s population. For example, the entire US population is less than 1/3 of India’s. So I don’t see how I can be having much of an environmental impact globally. If you want to reduce environmental impact, go over to India, and talk to people there.”
Environmental Impact = Population X Affluence X Technology
(or, Env. Impact = Population X Consumption)
Humans’ environment impact is a product of both the number of people and their consumption levels. Thus, even though the US has a much smaller population than India, the high rate of per capita consumption in the US means that, by some measures, the US has more environmental impact than a much more populous country such as India.
