Agriculture PDF

MIDTERM Topics *Origin of Agriculture *People and Agriculture *Food and Medicinal Plants *People and Forests *Temperate Forests:Use and Management *Tropical Forests: Use and Management Origin of Agriculture The development of agricultural about 12,000 years ago changed the way humans lived. They s...

MIDTERM Topics *Origin of Agriculture *People and Agriculture *Food and Medicinal Plants *People and Forests *Temperate Forests:Use and Management *Tropical Forests: Use and Management Origin of Agriculture The development of agricultural about 12,000 years ago changed the way humans lived. They switched from nomadic hunter-gatherer lifestyles to permanent settlements and farming. The Farming Revolution Taking root around 12,000 years ago, agriculture triggered such a change in society and the way in which people lived that its development has been dubbed the “Neolithic Revolution.” Traditional hunter-gatherer lifestyles, followed by humans since their evolution, were swept aside in favor of permanent settlements and a reliable food supply. Out of agriculture, cities and civilizations grew, and because crops and animals could now be farmed to meet demand, the global population rocketed—from some five million people 10,000 years ago, to eight billion today. There was no single factor, or combination of factors, that led people to take up farming in different parts of the world. In the Near East, for example, it’s thought that climatic changes at the end of the last ice age brought seasonal conditions that favored annual plants like wild cereals. Elsewhere, such as in East Asia, increased pressure on natural food resources may have forced people to find homegrown solutions. But whatever the reasons for its independent origins, farming sowed the seeds for the modern age. Plant Domestication The wild progenitors of crops including wheat (Triticum aestivum), barley (Hordeum vulgare), and peas (Lathyrus oleraceus) are traced to the Near East region. Cereals were grown in Syria as long as 9,000 years ago, while figs (Ficus carica) were cultivated even earlier; prehistoric seedless fruits discovered in the Jordan Valley suggest fig trees were being planted some 11,300 years ago. Though the transition from wild harvesting was gradual, the switch from a nomadic to a settled way of life is marked by the appearance of early Neolithic villages with homes equipped with grinding stones for processing grain. The origins of rice and millet farming date to the same Neolithic period in China. The world’s oldest known rice paddy fields, discovered in eastern China in 2007, reveal evidence of ancient cultivation techniques such as flood and fire control. Farmed Animals Cattle (Bos taurus), goats (Capra hircus), sheep (Ovis aries), and pigs (Sus domesticus) all have their origins as farmed animals in the so-called Fertile Crescent, a region covering eastern Turkey, Iraq, and southwestern Iran. This region kick-started the Neolithic Revolution. Dates for the domestication of these animals range from between 13,000 to 10,000 years ago. Genetic studies show that goats and other livestock accompanied the westward spread of agriculture into Europe, helping to revolutionize Stone Age society. While the extent to which farmers themselves migrated west remains a subject of debate, the dramatic impact of dairy farming on Europeans is clearly stamped in their DNA. Prior to the arrival of domestic cattle in Europe, prehistoric populations weren’t able to stomach raw cow milk. But at some point, during the spread of farming into southeastern Europe, a mutation occurred for lactose tolerance that increased in frequency through natural selection thanks to the nourishing benefits of milk. Judging from the prevalence of the milk-drinking gene in Europeans today—as high as 90 percent in populations of northern countries such as Sweden—the vast majority are descended from cow herders. People and Agriculture Agriculture, the cultivation of food and goods through farming, produces the vast majority of the world’s food supply. It is thought to have been practiced sporadically for the past 13,000 years, and widely established for only 7,000 years. In the long view of human history, this is just a flash in the pan compared to the nearly 200,000 years our ancestors spent gathering, hunting, and scavenging in the wild. During its brief history, agriculture has radically transformed human societies and fueled a global population that has grown from 4 million to 7 billion since 10,000 BCE and is still growing. The road to the present has not been smooth. Resource degradation, rapid population growth, disease, changing climates, and other forces have periodically crippled food supplies, with the poor bearing the brunt of famine. We still face many of the same challenges as our ancestors, in addition to new and even greater threats. To successfully navigate an uncertain future, we can begin by learning from the past. Paleoanthropologists have estimated that the earliest fossil evidence of Homo sapiens—anatomically modern humans—is roughly 196,000 years old.For the vast majority of the time since our species’ arrival on the evolutionary scene, we acquired food by gathering it from the wild.Wild plant-based foods and fungi were important staples in the paleolithic diet, including the wild ancestors of some species that are widely cultivated today.While the ancestral hunt for wild animals is often depicted as an epic conflict against woolly mammoths, woolly rhinos, giant elk, and other prehistoric megafauna, early humans also took to foraging for humble insectsand scavenging the remains of dead animals. From as early as 11,000 BCE, people began a gradual transition away from a hunter-gatherer lifestyle toward cultivating crops and raising animals for food. The shift to agriculture is believed to have occurred independently in several parts of the world, including northern China, Central America, and the Fertile Crescent, a region in the Middle East that cradled some of the earliest civilizations. By 6000 BCE, most of the farm animals we are familiar with today had been domesticated.1 By 5000 BCE, agriculture was practiced in every major continent except Australia. Why did people give up hunting and gathering for farming? There are many plausible reasons, all of which likely played some role at different times and across different parts of the world: Changes in climate may have made it too cold or too dry to rely on wild food sources. Greater population density may have demanded more food than could be harvested from the wild, and farming provided more food per acre, even if it did require more time and energy. Overhunting may have helped push woolly mammoths and other megafauna to extinction. Changing technology, such as domesticated seeds, would have made agriculture a more viable lifestyle. Food and Medicinal Plants Medicinal plants or medicinal herbs have been identified and used since ancient times to improve the sensory characteristics of food. The main compounds found in plants correspond to four major biochemical classes: Polyphenols, terpenes, glycosides and alkaloids. Plants synthesize these compounds for a variety of purposes, including protection of the plant against fungi and bacteria, defense against insects and attraction of pollinators and dispersal agents to favor the dispersion of seeds and pollens. Nowadays, there is also a growing interest in medicinal plants as natural alternatives to synthetic additives in foods because herb and spices are generally recognized as safe (GRAS) and are excellent substitutes for chemical additives. The major activities of extracts and herbs from medicinal plants are antimicrobial, anti- inflammatory, bactericidal, antiviral, antifungal and preservative for foods. The use of natural preservatives to increase the shelf life of food systems is a promising technology since many vegetal substances show antioxidant and antimicrobial properties. Taking into account all these considerations, recent changes in legislation controlling the use of animal feed additives and increased demand by consumers for healthier meat products, if possible free of chemical additives, have stimulated interest in bioactive secondary metabolites from medicinal plants as alternative performance enhancers. People and Forest People are at the centre of forestry development. How they interact with forests both as managers and users will determine whether forestry as we know it today remains a viable proposition. The Asia-Pacific region is a leader in developing collaborative forest management (CFM) even though achievements to date are scattered and in many countries the process has yet to become mainstream. Still, CFM has the potential to consolidate and enter the mainstream, to the benefit of millions of poor rural communities. Furthermore, as the region with the largest total urban population in the world, Asia also has an opportunity to seize leadership in urban forestry. Asia's cities represent the full spectrum of wealth and poverty, the inhabitants of which demand everything from a green environment to forest products for their daily lives. Forestry must find ways to satisfy these urban demands despite the high price of land and competition from alternative uses. The people most intimately related to forests are the hunter-gatherer populations for whom forests offer shelter, fuel and food. Progressively less close are relationships, for example, with carpenters whose livelihoods depend on wood; artisan brick makers, fishermen and tobacco farmers who use wood as fuel for smoking or drying produce; and city dwellers who daily use paper derived from wood. Forests can contribute to human livelihoods in many other ways including household (subsistence) or commercial uses of wood, NWFPs and services; food security, including through income generation; and employment. Forests also serve the age-old role of being a land bank upon which agriculture and other land developments draw. The above are relationships of dependency and consumption but many people also relate to forests in terms of how they participate in forest management. Whether relationships are dependency-oriented or management-oriented, there are normally important gender considerations. Rural communities continuously adapt in response to economic developments, migrations and other social change. The relationships of both men and women with forests will also have to adapt over time but the effects will not necessarily be the same for the two groups. Three main types of people/forest relationships cover the spectrum of livelihood benefits: · People who live inside forests: often surviving as hunter-gatherers or shifting cultivators, and who are heavily dependent on forests for their livelihood. Such people are often indigenous minority ethnic groups and tend to be outside both the political and economic mainstream; however, non-indigenous migrants into forests are also becoming significant. · People who live outside but near forests: farmers generally practising their agriculture outside the forest, who regularly use forest products in their agricultural activities (e.g., as sources of fodder or manure), for subsistence or for income generation. · People engaged in forest-based commercial activities: trapping, collecting minerals or employed in forest industries such as logging. As income is often derived from forest-dependent labour, this type of people/forest relationship exists in both developing and highly industrialised societies. Some people in this group may also pursue some subsistence practices. Temperate forest: use and management Temperate forests in all regions of the globe have been significantly altered by human activities for thousands of years. Their moderate climates, fertile soils, and vegetation productivity have been favorable to human settlement and clearing for agriculture, as well as direct use of trees themselves for lumber and fuels. Agricultural and settlement activities have included development of urban areas, widespread grain and other crop (e.g., corn, vegetables) cultivation, grazing, gathering of mulch, and alteration of natural water drainage. Under these historical pressures, it is estimated that only 1–2% of the original temperate forest remains as never-harvested remnants scattered around the globe. The vast majority of temperate forest land cover is in secondary forest responding to human harvest or other human-induced disturbance. The longest histories of substantial forest clearing have been in Asia and Europe. The temperate forest is globally important and unique. They host the largest and oldest organisms in the world. They serve as the world's major source of timber and wood products and are perhaps the only forests with some proven potential for sustainable management. The biomass of at least some temperate forests stands exceeds that of any tropical forest. The temperate forests of the world also provide critical ecosystem services locally and globally. Tropical Forests: Use and Management Do you think of tropical forests as faraway places that have nothing to do with your daily life? Think again. You rely on forests more than you know. tropical forests are home to howler monkeys, armadillos, and sloths. What could they possibly have to do with you? Plenty, as a matter of fact. For starters, they provide vital services, like stabilizing climate and absorbing carbon dioxide. But they also offer a vast array of products that many of us use on a daily basis. The world’s most popular fruit, the banana, comes from the rainforest. Once notorious for worker and environmental abuses, the banana industry has changed its ways. Other staples that come from rainforests include citrus, cassava, and avocado, as well as cashews, Brazil nuts, and ubiquitous spices like vanilla and sugar. Then there are a few foods that many of us consider life-giving—coffee, tea, and cocoa—and yes, they come from tropical forests, too. If we are not careful, however, our appetites for these products could destroy the source from which they come. Agriculture is responsible for more than 70 percent of deforestation in the tropics, MEDICINE Many of the Western medicines that we use today are derived from plants found in tropical forests. Medications to treat or cure inflammation, rheumatism, diabetes, muscle tension, surgical complications, malaria, heart conditions, skin diseases, arthritis, glaucoma, and hundreds of other maladies, come from forest plants. SHELTER Tropical forests yield some of the most beautiful and valuable woods in the world, such as teak, mahogany, rosewood, balsa, sandalwood, and countless lesser-known species. These woods surround us at home and in offices in the form of furniture, cabinets, paneling, and more. But only recently has the industrialized world realized the limits to timber extraction. Just like agriculture, logging can either nurture or destroy an ecosystem. It is up to us to support environmentally responsible logging and promote smarter wood production and consumption around the world. Other forest products show up in your home and office, too. Tropical forest fibers are found in rugs, mattresses, ropes, strings, and fabrics. CLEANING, COSMETICS, AND MORE Tropical forest oils, gums, and resins are used in insecticides, rubber products, fuel, paint, varnish, and wood finishing products. And tropical oils are key ingredients in cosmetics, soaps, shampoos, perfumes, disinfectants and detergents. CLIMATE CONTROL Perhaps one of the greatest gifts forests bestow upon us is their capacity for absorbing the monstrous amount of greenhouse gas emissions we humans generate. They are one of the world’s primary carbon reservoirs, absorbing carbon dioxide from the air, storing it, and generating oxygen. Forests are vital to the hydrologic cycle (rain and water systems), and they maintain some of the world’s most fragile soils. Rainforests also act as the world’s thermostat, regulating temperatures and weather patterns. As we always say: forests are our best defense against climate change. That’s why the Rainforest Alliance has spent more than 30 years working to conserve forests and to improve the lives of those who depend upon them. The loss of our forests, together with the way that this cleared land is used after the forest is cleared, contributes to between 9-11 percent of total greenhouse gas emissions each year—almost as much as all the world’s trains, planes, and automobiles combined. But by stopping the destruction of mature (old-growth) forests, we prevent a huge amount of carbon from going into the atmosphere, and by promoting Earth-friendly planting and management of young forests, we absorb large amounts of atmospheric carbon. THE FUTURE A whopping 30 percent of the world’s forests has been destroyed, while another 20 percent has been degraded (and most of the rest has been fragmented, leaving only about 15 percent intact). Our world is facing the greatest extinction crisis since the fall of the dinosaurs some 65 million years ago. The future of many of Earth’s plants and animals—and hundreds of human cultures—will be determined within the next few decades. Because we are so dependent on the forest’s great bounty, we need to act responsibly, be good stewards of the Earth’s tropical forests, and do all we can to ensure that forests— and their many gifts—are around for future generations.