AGRICULTURE and HUMAN IMPACT on the BIOSPHERE Chapter

AGRICULTURE and HUMAN IMPACT on the BIOSPHERE Chapter 6 Slide show by Kelly Riedell/Brookings Biology

HUMAN POPULATION You are here http: //www. learner. org/jnorth/spring 2002/species/spring/Update 041902. html#Humankind

https: //mycupofcareisempty. files. wordpress. com/2011/11/overpopulation. gif WORLD POPULATION World clock • Current world population is just 7 BILLION over _______ • Estimates predict it will reach 9 billion by 2050 http: //www. peopleandplanet. net/

Does this look familiar? What is the Earth’s carrying capacity? ?

SUSTAINABILITY How can we grow enough food for all the people on the planet without destroying the environment? http: //www. enjoy. org/hstech/Hunger. Site 02/america/Ford. Schwartz/ http: //ejcw. org/wp-content/uploads/2015/08/640 x 360 -ag-runoff. jpg

Importance of Agriculture By middle of 20 th century, despite agricultural advances there were ________in many food shortages parts of the world. http: //www. enjoy. org/hstech/Hunger. Site 02/america/Ford. Schwartz/ Governments and scientists began a major effort increase food production to ______

GREEN REVOLUTION _____ strains 1. New plant ____ had higher yield & resisted pests 2. Modern farming_____ techniques allowed planting larger areas fertilizers & ______ pesticides 3. Chemical ______ boosted crop production and controlled pests http: //interactive. usask. ca/ski/media/stills/agriculture/crops/t_plant-breeder. jpg

HOW DO WE GROW MORE FOOD? Large fields are planted with a single variety year after year = MONOCULTURE ______ http: //imagesource. allposters. com/images/NGSPOD 04/107870. jpg

MONOCULTURE Allows farmers to grow large quantities of food BUT. . . http: //agronomyday. cropsci. illinois. edu/2003/csrec-welcome/aeriel-view. jpg

But. . . HAS HUGE IMPACT ON ECOSYSTEMS _____ Fertilizers increase yield BUT. . . RUNOFF can cause algal blooms and DEAD ZONES ______ http: //www. biology-blog. com/images/blogs/10 -2007/fertilizer-15101. gif

But. . . HAS HUGE IMPACT ON ECOSYSTEMS Pesticides kill insects that damage ____ crops BUT. . . beneficial insects too they kill ____ Bees Hand pollination http: //cms 1. good. is/posts/full_1289265646 pesticides. jpg http: //www. fllt. org/content/uploads/2014/12/1 -Honey-Bee-001. jpg

Example: _____ DDT was first modern insecticide It was cheap, stayed active for long time, and killed many different insects Used to control agriculture pests and disease carrying MOSQUITOES ________ http: //www. michigan. gov/images/mosquito_65147_7. jpg

http: //www. ci. cypress. ca. us/public_works/stormwater_images/kids_watershed. jpg When DDT was sprayed, runoff carried it into rivers and streams in LOW concentrations. http: //www. geocities. com/~greyhawk_1/s h_eagle-9. jpg DDT then passes into organisms through the food chains ______, is stored tissues in _______, and degrade doesn’t ______. http: //www. geocities. com/~greyhawk_1/sh_eagle-9. jpg

BIOLOGICAL MAGNIFICATION _______________ = the concentration ______ of a harmful substance increases ______as it passes to organisms at higher trophic ________levels in food chain or web. Plants pick up DDT from water & store it → Herbivores eat plants and store some DDT → Carnivores eat herbivores and store more DDT

The wide spread use of DDT threatened many species… especially fish eating birds like osprey, brown pelican, and bald eagles. http: //image 10. webshots. com/11/3/94/67/2146394670011493049 pwl. CDV_ph. jpg DDT causes birds to lay fragile eggs with ______ shells so eggs would break when sat on. American Bald Eagle was declared endangered in 1967. It has since been “threatened” reclassified as ___________

http: //www. kimball. k 12. sd. us/Heroes%20 Web%20 Page/Pictures/Rachel%20 Carson. jpg In 1962, American biologist Rachel Carson published the ________ book, _______ Silent Spring which told of DDT’s harmful effects. The book led to a large public outcry and banned eventually resulted in DDT being _____ in the United States in the 1970’s The book was one of the important events in environmental movement the birth of the _____________.

But. . . HAS HUGE IMPACT ON ECOSYSTEMS Wearing away of topsoil = Soil erosion is caused by plowing _____ land removing plant roots http: //coweeta. ecology. uga. edu/coweeta_photographs/erosion. htm

But. . . HAS HUGE IMPACT ON ECOSYSTEMS http: //i. telegraph. co. uk/multimedia/archive/02075/COW_2075448 c. jpg ____ Runoff from feedlots and fields can contaminate surface and ground water ______ Deforestation happens to clear trees for beef farms water and Raising cows uses lots of ______ releases ____ methane into the atmosphere increasing climate change.

Impact of Agriculture Desertification = changing of fertile _______ land in dry climates into desert areas caused by farming, overgrazing, and drought http: //4. bp. blogspot. com/-Pao 2 Oe 2 O_W 0/U 5 F 99 ppqi. II/AAAAAl. Y/rlb. QFo. R 4 b 2 c/s 1600/invisible+fences+1. jpg

But. . . HAS HUGE IMPACT ON ECOSYSTEMS Many Midwest states rely OGALLALA aquifer on the _____ for their water needs. We are using water faster water than the ______cycle can replace it. Evidence indicates this aquifer may run dry _____ within 20 -40 years. http: //www. suu. edu/faculty/bowman/Econ 1740/Heilbroner. Zinn/ogallala_aquifer_map_pic_2. gif

FRESH WATER RESOURCES Americans use BILLIONS of gallons of freshwater daily for ____, ____ drinking washing and __________ watering crops http: //www. thesolutionsite. com/lesson/4601/freshwater. jpg

HOW DO WE HELP? technology is changing how farmers Modern_____ farm and lessening the impact on the environment. EX: Satellite _____ imaging GPS technology _____ enable farmers to only apply chemicals needed where_____

HOW DO WE FIX IT? “No-till” keeps plant residue in fields ____ Reduces _____ soil erosion and protects ecosystems from runoff http: //cbarc. aes. oregonstate. edu/images/no-till. jpg

HOW DO WE FIX IT? Planting legumes, alfalfa, grasses and other _____ Cover crops keeps plants on soil between food crops soil erosion and protects - reduces _____ ecosystems from runoff weeds - reduces ______ - reduces need for fertilizer

HOW DO WE FIX IT? Crop rotation _______ alternates what is crops are planted each year. insects without - helps control ____ pesticides legumes - alternating with _____ replenishes soil nutrients without fertilizer

HOW DO WE FIX IT? Controlled grazing = managing graze ________ periods and herd densities - improves nutrient cycling - retains water prevents desertification - ____ http: //www. uaex. edu/farm-ranch/animals-forages/images/006. jpg

HOW DO WE FIX IT? Biological _____ pest control uses natural predators like insects or spiders to kill insects instead of chemical pesticides http: //static. dudeiwantthat. com/img/outdoors/garden/1500 -live-ladybugs-11829. jpg

HOW DO WE FIX IT? Contour plowing ________ = on hilly areas, plowing is done across the hill rather than straight up and down erosion from runoff - prevents soil _______ http: //images. slideplayer. com/24/7068759/slides/slide_25. jpg

HOW DO WE HELP ? • Water conservation • Protect wetlands and forests • Water treatment plants • Clean water regulations hhttp: //www. romanviii. co. uk/bp/nhpage. asp? pcat=about_us

WAYS TO CONSERVE WATER http: //www. watersavingtips. org/images/saving_1. jpg

WHAT CAN YOU DO? LESS meat - Eat _____ Per capita/year waste food - Don’t ______ Food waste ~ 1/3 of all food produced worldwide, ($1 trillion) gets lost or wasted ~ US avg: 20 lbs/person/month wasted http: //teacherweb. com/CA/Nogales. High. School/mespinoza/fig 50 Energy. Pyramid. jpg http: //languagesoftheworld. info/wp-content/uploads/2014/10/Meat-consumption-World. jpg

WHAT CAN YOU DO? - Be aware of ______ INVISIBLE water Water the is used to produce products that we don’t know or don’t think about The PRODUCTION OF: Change the way you think 1 kg wheat costs 1, 300 L water 1 kg rice costs 3, 400 L water Change the way you think 1 kg eggs costs 3, 300 L water about your laptop 1 kg beef costs 15, 000 L water 1 cotton shirt costs 2, 500 L water 1000 g of blue jeans costs 10, 850 liters water 1 ton passenger car costs 400, 000 liters of water Building a house uses about 6 million liters of water