GEOG 300i 1st Edition Lecture 10 FAO’s Global Forest Resources Assessment 2010 Forests cover 31% of total land area The world's total forest area is just over 4 billion hectares, which corresponds to an average of 0.6 ha per capita. The five most forest-rich countries (the Russian Federation, Brazil, Canada, the United States of America and China) account for more than half of the total forest area. Ten countries or areas have no forest at all and an additional 54 have forest on less than 10 percent of their total land area. FAO’s Global Forest Resources Assessment 2010 The rate of deforestation shows signs of decreasing – but is still alarmingly high Deforestation – mainly the conversion of tropical forests to agricultural land – shows signs of decreasing in several countries but continues at a high rate in others.  Around 13 million hectares of forest were converted to other uses or lost through natural causes each year in the last decade compared to 16 million hectares per year in the 1990s. Both Brazil and Indonesia, which had the highest net loss of forest in the 1990s, have significantly reduced their rate of loss, while in Australia, severe drought and forest fires have exacerbated the loss of forest since 2000. FAO’s Global Forest Resources Assessment 2010 Some background Forests once covered twice the area that they do today.  Large expanses converted or degraded to produce food, timber, and energy. The loss is continuing at a rapid rate. Just one fifth of the world’s original forest cover remains in large tracts of relatively undisturbed forest. But forests can recover.  http://www.wri.org/map/worlds-forests-restoration-perspective Some background Restoration of degraded lands is receiving increasing attention because:  climate change mitigation through carbon sequestration and  substitution of fossil fuels with biomass; These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute. climate change adaptation through creation of shade and buffers;  contributions to rural livelihoods through outgrower schemes and access to firewood;  increased food security;  reduced risk of flooding and mud slides;  biodiversity conservation through habitat improvement and migration corridors;  production of forest products.  Not all converted or degraded forests are suitable for restoration.  Some of the world’s most productive agricultural lands are former forests. But vast areas of marginal lands could grow trees again as part of multifunctional forest landscapes. http://www.wri.org/map/worlds-forests-restoration-perspective Along the boundary between forests and prairies, it was the forested lands that were first settled.  Settlers believed the prairie was unsuitable for settlement because of lack of wood and drinking water, lack of protection from winter storms, and the lack of trees, thought to be caused by infertile soils Settlement began in the early 1800’s, but even as late as 1836 only small prairies near woodlands were settled, despite the invention of plows capable of tilling the thick prairie sod and the high crop yields obtained from prairie soils. After the railroads were established in the 1850’s and 1860’s, crops and supplies could be transported economically, and the prairies were then rapidly settled. Before 1800, Illinois was nearly two-thirds prairie grassland and one-third forest, but by 1850 prairie habitat was reduced by 75%. Hansen et al. 2008 Share of Woodfuels in National Energy Consumption Lepers et al. 2005 “Changes in land cover and in the way people use the land have become recognized over the last15 years as important global environmental changes in their own right.  They are also intertwined in many ways with other environmental issues, such as climate change and carbon cycle, loss of biodiversity, sustainability of agriculture, and provision of safe drinking water.” Lepers et al. 2005 The authors look at 4 types of land use change:1. “forest-cover changes;2. degraded lands in the dry and hyperarid zones of the world (often referred to as desertification, even though most definitions of desertification do not include hyperarid zones);3. cropland expansion and abandonment; 4. urban settlements.” Lepers et al. 2005 The challenge in these global efforts is huge for a variety of reasons: Different datasets have different definitions  FAO definitions Forest includes natural forests and forest plantations. Deforestation occurs when forest is converted to another land cover or when the tree canopy cover falls below a minimum percentage threshold (10% for the FAO definition).  Cropland is FAO’s arable land: land under temporary crops, temporary meadows for mowing or pasture, land under market and kitchen gardens, land temporarily fallow (less than 5 years), and permanent crops; this category includes land under flowering shrubs, fruit trees, nut trees and vines, butexcludes land under trees grown for wood or timber). Croplands do not include planted pastures or natural grazing lands. Lepers et al. 2005 “The most commonly accepted definition of desertification is provided in the United Nations Convention to Combat Desertification: “land degradation in arid, semi-arid and dry subhumid areas resulting from various factors, including climatic variations and human activities,” land degradation being defined as the decrease or destruction of the biological productivity of the land. Hyperarid zones are generally not part of the definition of desertification because they are presumed to be so dry that human degradation is severely limited unless irrigation is practiced.” Lepers et al. 2005 The challenge in these global efforts is huge for a variety of reasons: Different datasets have different definitions  Different datasets have different spatial resolutions Different datasets have different temporal and spatial coverage These introduce BIAS.  Their solutions look at the highest rate of land-cover change given the definition adopted for a particular data set, rather than attempting to harmonize the definitions among data sets. Separate maps with numbers of datasets Lepers et al. 2005 Use of different types of data