Exam 2 review terms Colors represent different chapters ch6 ch7 ch9 ch10 Effects of seasonal migratory grazing However biologically rich coral reefs are very sensitive communities and can take a century or more to recover The health of most 55 public grazing lands in the U S is not good Overgrazing is damaging to vegetation and soil including loss of native forage species and erosion Wildlife conservation groups regard cattle overgrazing as the most ubiquitous form of ecosystem degradation and the greatest threat to endangered species in the southwest U S The solution is to confining animals to a smaller area for a sort time often only a day or two before shifting them to a new location simulate the effects the wild herds Helps instead of destroying grasslands Nature preserve corridors Connects smaller habitat areas Works out very well when a big preserve isn t possible Effectively it can create a large preserve out of several small ones Marine vs terrestrial reserve management Most societies also set aside natural areas for aesthetic or recreational purposes Currently nearly 14 of the land area of the earth is protected in some sort of area Marine preservation is relatively new Only about 5 of nearshore marine biomes are protected Limiting the amount and kind of fishing in marine reserves can quickly replenish fish stocks in surrounding areas Global changes in deserts Desserts are becoming bigger Percentage of old growth forests Old growth forest large enough area undisturbed by human activities where trees can live out a natural life cycle Today only 25 of forests are old growth forests Locations of forest loss Continent by continent figure 6 4 Africa South America Caribbean near east middle east and North America in order from greatest forest loss to least Dominant uses of wood 1 5 of all wood consumption is to produce paper fuel wood accounts for of global wood consumtion At least 2 billion people depend on charcoal or wood for as a principal source of heating or cooking fuel Problems with loss of tropical forests Tropical forests now occupy less than 10 of the earth s land surface these forests are thought to contain more than 2 3 of all higher plant biomass and at least of all the plant animal and microbial species in the world Lose 5 20 million hecta acres a year Also Economic value is lost along with cultural value harsher climates Also more pest and disease resistant Aspects of monoculture forestry Single species single use Although promotes rapid growth and easier harvesting supports very little biodiversity does poorly in providing ecological services such as soil erosion control and clean water production Global percentage of protected lands About 14 of the world s forest are in some kind of conservation status Parks and reserves in developing nations Different challenges poorer place have more problems with poaching for food poaching for ivory lack of funds to enforce protection Too busy trying to survive Forest harvest methods Clear cutting in which every tree in a given area is cut regardless of size Shelter wood Harvesting mature trees are removed in a series of 2 or more cuts Strip Cutting all trees in a narrow corridor are harvested Least disruptive Selective cutting small percentage of the mature trees are taken down in each 10 or 20 year rotation Ranchers and rangeland restoration Have been trying rotational grazing confining animals to a small area for a short time a day or two before shifting them to a new location raise wild species such as impala wildebeest Oryx or elk because they forage more efficiently and can withstand Aspects of edge habitats more open bright and windy than a forest interior temp and humidity is varied As a result deep forest shade loving species disappear Boundry between two types of land ecosystems Prevalent forest types Boreal Tropical moist Wind erosion Wind and Water are the main agents that move soil around Farming accelerates erosion Happens when plant cover and surface litter are removed from the land by agriculture or grazing soil is loose and wind lifts this Locavore locavore a person who consumes locally produced food Benefits of sustainable farming Less erosion book Better quality meat Lower production costs higher price Preserves culture preserves rural towns as supports local business Basic soil layers Topsoil organic matter humus living organisms Inorganic minerals Zone of leaching dissolved or suspended materials move downward Subsoil Accumulation of iron aluminum humic compunds and clay leached down from above Parent material inorganic material Natural disaster drought War armed conflict and political oppression overreliance on a particular food source Irish potato famine cause Potato blight undiversified crops over reliant on potatoes Meat production problems Not efficient could feed at least 8 times more people with corn and grains feed to livestock Bacteria in a manure in the feedlots or liquid wastes in manure storage location lagoons holding tanks around hog farms can escape into the environment Constant use of antibiotics may be producing antibiotic resistant diseases Slowly rendering standard anti biotic as useless Super bacteria Kyoto Protocol Kyoto protocol in 1997 160 nations agreed to roll back CO2 Methane and nitrous oxide emissions about 5 percent below 1990 levels by 2012 China and India were exempted from the agreement and the US never ratified this agreement Temperature inversion Warm air gets on top of cold air seals in pollution Health effects of air pollution Increased probability of heart attacks respiratory disease and lung cancer Bronchitis and emphysema Causes of hunger widespread hunger arises when political instability war and conflict displace populations removing villagers from their farms or making farming to dangerous to carry on There is enough food in the world it is just not distributed evenly Natural fertilizers Manure compost Interplanting and rotating legumes or beans book Obesity percentage About 1 3 of us are seriously overweight obese meaning more than 20 over the ideal weight for a persons height and sex Community Supported Agriculture CSA Farms supported by local residents who pay ahead of time for shares of the farms products which can vary from vegtables to flowers to meat and eggs Famine multipliers First noticeable effects of El Nino 212 Disappearing fish in Peruvian coast where water had temporally warmed Four atmosphereic zones Troposphere stratosphere mesosphere