Industrial Agriculture & Forests

Agriculture is the primary driver of deforestation in all tropical areas of the world. In the Amazon basin and Latin America, cattle ranching is the primary agricultural activity, while soy, palm oil, and traditional shifting cultivation make up small percentages of total land use in former forest area[1] [2]. In the rainforests of the Congo basin and Africa, traditional agriculture is the most common form of agricultural land use, although commercial agriculture of crops such as palm oil is growing[3]. In Southeast Asia, the palm oil sector is the primary driver of forest conversion[4].     

Most studies find that while small scale agriculture is driven by population pressures and in some cases national settlement policies, intensive agricultural development is driven by global commodity prices[5] [6]. From 2000-2008, increases in prices of commodities such as soy and oil palm drove large scale land conversion in Southeast Asia and the Amazon. Conversely, low agriculture prices can lead to the abandonment and revegetation of agricultural or pasture land, as has happened with corn in Mexico and coffee in Colombia in the past few decades[7]. Medium scale agriculture was be promoted by government sponsored migration policies, such as in Brazil and Indonesia[8], cultivation subsidies, such as in Mexico[9], and numerous other countries where land clearing is encouraged for land tenure, especially the Amazon[10].

Conversion of forest to intensive agriculture can have profound impacts on forest health. Monoculture plantings will quickly exhaust the thin layer of nutrients in tropical soils. Runoff from agricultural land often contains elevated nutrient levels and can cause problems with water pollution. Large farms provide little wildlife habitat and can contain almost zero plants in the understory. Fragmentation from farms can have negative impacts on surrounding forests by isolating animal populations and altering microclimates at forest edges[11]. In Brazil, forest clearing for intensive agriculture normally involves larger clearings than pasture[12]. Finally, farm biomass and soil sequesters a fraction of the carbon as forests[13].

Cattle ranching - In many areas of the tropics, especially the Amazon basin, cattle ranching is preferred to crop cultivation. In areas of poor soil fertility, crop yields drop after just a few cycles, while cattle ranching can continue for many years. In remote areas of the Amazon, cattle ranching requires less capital and labor input; clearing land for pasture is also used to stake tenure claim to land. In the Brazilian Amazon, ranches are often large and held by a smaller number of wealthy landowners[14]. Ranching often follows initial forest clearing for timber; high grade timber is removed and remaining slash is burned in order to stimulate soil fertility.   

Palm oil – In other tropical areas, crops such as palm oil, and to a lesser extent soybean are grown for their oil. Palm oil is used for cooking oil and food processing in most of the developing world, as it yields more oil per land area than other biofuel crops[15]. Palm oil is found in chocolate, potato chips, and other snack foods, as well as soaps and many cosmetics; palm oil is also used often as a biofuel. Oil palm, a tree originally from West Africa, is grown primarily in Malaysia and Indonesia, but is expanding around the world. Palm oil plantations are a massive driver of deforestation in Southeast Asia; studies have found that about half of palm oil plantations established from 1990-2005 occurred in forests[16]. In Borneo / Kalimantan, palm oil often replaces high carbon peat swamps, resulting in a significant global carbon loss compared to fossil fuels.

[1] Fearnside, P. M. (2005). Deforestation in Brazilian Amazonia: history, rates, and consequences. Conservation biology, 19(3), 680-688.

[2] Rudel, T. K., Defries, R., Asner, G. P., & Laurance, W. F. (2009). Changing drivers of deforestation and new opportunities for conservation. Conservation Biology, 23(6), 1396-1405.

[3] Mayaux, P., Pekel, J. F., Desclée, B., Donnay, F., Lupi, A., Achard, F., … & Belward, A. (2013). State and evolution of the African rainforests between 1990 and 2010. Philosophical Transactions of the Royal Society B: Biological Sciences, 368(1625), 20120300.

[4] Boucher, D., Elias, P., Lininger, K., May-Tobin, C., Roquemore, S., & Saxon, E. (2011). The root of the problem: what’s driving tropical deforestation today?. The root of the problem: what’s driving tropical deforestation today?.

[5] Morton, Douglas C., et al. “Cropland expansion changes deforestation dynamics in the southern Brazilian Amazon.” Proceedings of the National Academy of Sciences 103.39 (2006): 14637-14641.

[6] Grau, H. Ricardo, and Mitchell Aide. “Globalization and land-use transitions in Latin America.” Ecology and Society 13.2 (2008): 16.

[7] Rudel et al. (2009).

[8] Fearnside, Philip M. “Transmigration in Indonesia: lessons from its environmental and social impacts.” Environmental Management 21.4 (1997): 553-570.

[9] Lawrence, Deborah, et al. “Untangling a decline in tropical forest resilience: Constraints on the sustainability of shifting cultivation across the globe.” Biotropica 42.1 (2010): 21-30.

[10] Geist, Helmut J., and Eric F. Lambin. “Proximate causes and underlying driving forces of tropical deforestation.” BioScience 52.2 (2002): 143-150.

[11] Laurance, William F., et al. “Ecosystem decay of Amazonian forest fragments: a 22‐year investigation.” Conservation Biology 16.3 (2002): 605-618.

[12] Morton et al. (2006). 

[13] Silver, W. L., Rebecca Ostertag, and A. E. Lugo. “The potential for carbon sequestration through reforestation of abandoned tropical agricultural and pasture lands.” Restoration ecology 8.4 (2001): 394-407.

[14] Fearnside (2005).

[15] Chisti, Y. (2007). Biodiesel from microalgae. Biotechnology advances, 25(3), 294-306.

[16] Koh, L. P., & Wilcove, D. S. (2008). Is oil palm agriculture really destroying tropical biodiversity?. Conservation letters, 1(2), 60-64.