Chapter 14: Balancing Agriculture and Conservation
Integrate Pest Management (IPM)
A suite of techniques to help reduce the use of synthetic pesticides. Farmers monitor crops and use natural methods of pest control like increasing population of pest predators. Only spray chemicals when all other methods fail. Other farmers may spray on a regular schedule, regardless of whether it's actually needed.
Colony Collapse Disorder (CCD)
All adult honeybees suddenly disappear from a hive, even though there is a queen bee, sufficient food resources, and developing larvae is becoming more common 2005-2006 in the U.S. and Europe. The cause has not been pinpointed but recent experiments show the incidence is higher in colonies exposed to neonicotinoids.
Beginning Box (bees)
Bees have been declining to a variety of reasons: habitat loss, pathogens and parasites, climate change, poor hive management, and lack of genetic diversity. A recently discovered reason is chemical pesticides used in agriculture, particularly neonicotinoids that disrupt foraging behaviors and production of queens. Crop scientists worry that decrease in abundance and diversity of insect pollinators will harm crop production. Pesticide use is necessary for some agriculture, but can harm pollinators and undermine the productivity they seek to produce.
Box 14.2 (Coffee farms)
Coffee is grown in tropical areas, the most biodiverse areas on the planet. The shade-grown coffee allows there to be ecological and ecosystem benefits in addition to production of coffee. Sun-grown coffee leads to a shift in traditional methods and does lead to higher yields of coffee but require more agricultural maintenance and causes more harm. Have more ecological and economic cost, but farmers grow it in hopes that the higher yield will offset costs. Sometimes land is illegally cleared within preserves for coffee farms. Shade-grown labels on coffee hope to indicate growers that are sustainable farmers, however this labeling may be false (like only 1 shade tree left). Need to define shade-grown better. This coffee is more expensive, but consumers may be willing to pay for sustainable production.
Land sparing strategy
Food is produced in highly industrialized monocultures (large fields of single crop species) that yield the largest possible amount of food per area unit. Even though the land doesn't have much wildlife, the agriculture doesn't take up much space. The remaining area could be made into a reserve.
Figure 14.15 (environmental impact of animal protein)
Graphs show the energy requirement of an adult in the U.S. in terms of land use, irrigation water, CO2 emission, and reactive nitrogen. These graphs show that beef is the worst in terms of environmental impact- the most land, irrigation water, CO2 emitted, and nitrogen used in its production. Clear idea is to reduce amount of beef eaten.
Figure 14.5B,C (infection intensity)
Graphs that show the correlation of increased snail biomass with increased infection and increased infection with increased deformities.
Figure 14.10 (hedgerows)
Hedgerows are important because they provide habitat and serve as dispersal corridors for wildlife including insects, birds, and small mammals. Have created measures to protect and encourage development of them
Box 14.1 (Amphibians and Eutrophication)
Hind limb deformities are caused by a trematode parasite. These deformities are increasing, 15-90% of a population can show them. Possible hypothesis is that this linked to increased nitrification. They found increased eutrophication caused increased parasite load. Also, amphibian exposure to the fertilizers caused a decreased immune response, due to decrease in leukocyte numbers.
Figure 14.5A (snails)
In 27 Michigan ponds, phosphorous concentration was positively associated with biomass of snails that serve as hosts for trematodes which can then infect amphibians. The biomass increased because of more algae growth due to increased fertilization.
End Box: Conservationist's Dinner Plate
Is it as simple as vegetarian, locally grown, and organic? May not be able to prescribe on particular diet. Protein from animals uses up more land and produces more greenhouse gases than plant-based proteins. The worst protein is beef in terms of environmental impact. Can somewhat reduce impact by buying locally since the food doesn't have to travel as far, but this is only one consideration in energy use of food production, production has a higher energy use than transportation of food often since areas differ in their efficiency. Still, eating local can be helpful in supporting local businesses and connecting to local agriculture. GE crops also generally increase the environmental sustainability of crops even though people eschew the crops due to ethics of biotechnology or worry over health. Even organic farmers are allowed to use some pesticides and fertilizers, so this farming may not be entirely sustainable and "natural." Labels do not necessarily mean that a food product is more sustainable. The best way to reduce impact it reduce amount of animal-protein, especially beef, in our diet.
Figure 14.4 (frog deformities)
Shows a picture of a frog with limb deformities in its hind legs. These deformities seem to be increasing.
Figure 14.1 (Indonesia Farms)
Shows that ab area that was meant to be protected was cleared for coffee farms in Indonesia, illegally between 1976-2006. Analysis of satellite images reveals significant loss of forest within the park.
Figure 14.9 (nutrient retention manures)
Shows that farms that use manures or legumes for soil fertility have higher rates of nutrient retention than systems based on chemical fertilizers. This then decreases the leaching of nitrates and eutrophication of surrounding areas.
Figure 14.13 (organic yields)
Shows that on average, yields are 25% lower in organic systems compared to conventional crop systems Doesn't mean organic farming doesn't work, may mean there needs to be more research and attention to improve yields of organic farms. If can maintain high yields could also better maintain soil fertility, water, and nutrients this would be better than conventional agriculture.
Figure 14.6 (location of dead zones)
Shows the global distribution of dead zones, concentrated around Eastern U.S., Western Europe, and Southeast Asia.
Figure 4.11 (agricultural practices A and B species)
Shows the species response to agricultural practices. Some species are highly sensitive to agricultural intensification (A) while other species can prosper under many different agronomic practices (B). These are two different hypotheses. If "A," is the species, no amount of agriculture is good. If "B," is the species, wildlife friendly agriculture could work.
Figure 14.4 (coffee farm models)
Shows two models for coffee production and the different qualities of habitat for wildlife. (A) shade-grown coffee shrubs beneath an intact canopy of native trees and (B) a sun-grown coffee plantation that requires land clearing. Shade growing reduces harmful effects to the native forest.
Biomagnification
Some chemical compounds are not easily broken down or excreted by plants or animals, so their concentration is greater in organisms higher in trophic level. Biomass of organisms decreases as trophic level increases, and this leads to increased concentration of the compound per unit biomass. This process happened with the use of DDT that leads to more fragile eggshells.
Secondary pest outbreak
Species other than the targeted pest become so numerous as to cause economic damage to crops. These can occur due to lack of natural enemies or decreased competition.
Figure 14.2 (soil quality in cities)
This graph shows that the development of urban centers in the U.S. has been concentrated in areas with the most productive soils for farms. This means that agriculture is pushed onto less fertile lands where they need more area to be productive.
• Figure 14.3 (nitrogen cycle)
This graph shows the global increase of anthropogenic sources of fixed nitrogen is the largest source of global nitrogen. The Haber-Bosch process uses large amounts of energy to convert nitrogen gas to ammonia which is used to make fertilizers. The total sum across all anthropogenic sources is shown, with fertilizers being the clear top emission of nitrogen. Leads to release of N2O, a greenhouse gas, into the atmosphere which has greater warming potential than CO2.
Pest resurgence
This happens when pesticides kill insect predators, parasitoids, and spiders (natural enemies) that could keep pest numbers in check. The targeted pest species bounces back to damaging levels after pesticide application, especially when many continuous or overlapping generations of insects are born
Wildlife friendly strategy
This is an organization of small agricultural fields interspersed within patches of habitat and corridors of native vegetation and pests controlled by birds, predatory insects, and spiders instead of chemical sprays. This land-sharing agriculture covers more usable land, but practices are compatible with wildlife.
Dead Zone
When nutrients enter the water, it can cause the formation of floating algae mats that block sunlight. When algae are decomposed by bacteria, the bacteria deplete oxygen from the water and create a dead zone where the vast majority of fish, shellfish, or other aquatic life leave the area or die. The number of dead zones has about doubled every decade.
Agroforestry
also known as silvopastoral farming. Entails the mixing of agriculture, forestry, and farming so that trees are grown among crops or pastures. Can increase profit for landowners and biodiversity and ecosystem services. Retains more wildlife, sustains soils, and sequesters more CO2. This happens due to deep root systems that improve soils and enhance carbon sequestration.
Low
external-input (LEI) agriculture- combines wildlife-friendly and land-sparing practices. In LEI systems, applications of synthetic pesticides and fertilizers are minimized by monitoring fields and using alternative agriculture practices. This is a partial integration of organic principles, which helps to reduce the impact of agriculture. For example, may only integrate crop rotation but this will reduce fertilizer use.
Figure 14.7 (gulf of Mexico)
fertilizers enter the Mississippi river from farms in the Midwest. Eventually, the river flows into the Gulf of Mexico and creates a vast dead zone. The area supports very little life, even though it was once an area with many fish and shrimp.
Genetically Engineered (GE) crops
genetically engineered crops are part of a recent advance in the green revolution and could potentially achieve higher yields and improve nitrogen use. In some countries, planting of GE crops has been prohibited. Technologically involves the transfer of DNA (transgenes) from one species to another. Ex. DNA from Bacillus thuringiensis into corn and cotton to make them pest-resistant. Has produced less pesticide usage, environmental benefits.
Figure 14.12 (organic farms biodiversity)
shows that diversity of insects, birds, and plants are on average 30% higher in organic agriculture, but the amount of improvement varies.
Eutrophication
the process where nutrients from fertilizers end up in aquatic ecosystems through soil leaching and cause explosive growth of phytoplankton, algae, and aquatic plants.
Organic Certification
the standards range from nation to nation, but usually requires that no synthetic fertilizers or pesticides are used for many growing seasons. Also emphasizes natural over technological approach. Often forbids GE crops and sterilization through radiation. However, doesn't mandate amenities for wildlife.
Green Revolution
the use of modern farming practices that include fertilizers, pesticides and irrigation. The result in industrial agricultures with monocultures, intense chemical use, and mechanized planting, cultivation, and harvest.
