Forests, Biodiversity, and Food Security

In the 1990s, Vietnam passed a series of legislation aimed at reversing the trend of deforestation that accompanied the country’s effort to increase it food security by producing enough rice domestically to feed its population.  Between 1980 and 1993, forest cover in Vietnam decreased from 38 percent to a low of 25 percent.   This decrease was largely a result of increased agricultural production encouraged by the centralized state to increase rice production commercially, and through smallholder subsistence farming.   Between 1950 and 1998, Vietnam nearly tripled its level of rice production from 7.6 to 21.3 million tons of paddy, making it the fifth highest producer in the world.   However, although Vietnam was producing enough rice to feed its population, unequal access to land and resources meant continued vulnerability to food insecurity for, among others, marginalized rural ethnic minority communities.  

After Vietnam liberalized its economy in the mid-1980s, the government passed a series of land-use laws to reverse the effects of deforestation through forest plantations and natural regeneration.   These laws were likely influenced by the requests of international environmental organizations and the proposition of global agribusinesses to which Vietnam would be more susceptible as it sought to increase trade and foreign direct investment in the international economy after the mid-1980s.  Through an examination of ten global, regional, and national satellite maps of forest cover in Vietnam coupled with fieldwork verification, Meyfroidt and Lambdin (2008) concluded that although the percentage of land covered in forest had increased rapidly between 1993 and 2005 to its pre-1980 level, forest biodiversity was likely lower due to the lower biomass in new forests, and increased habitat fragmentation.   Reforestation, however, also meant a decrease in cultivated agricultural land, to which the state responded by sponsoring programs to encourage the use of hybrid rice and maize seed to increase yields while utilizing a smaller area of land, albeit with the use of external agrochemical inputs.   Thus, while rice production has not suffered due to land use restrictions and reforestation, Turner and Pham (2015) claim that the land use land cover change in northwest Vietnam has resulted in continued food insecurity for rural ethnic minority farmers because of their increased dependence on the state and cash economy for seeds and agrochemical inputs, and the decreased productivity of the hybrid seeds in less than ideal growing conditions.

Thus, Vietnamese state policy has failed to addressed the food insecurity of marginalized rural ethnic minority communities through both state-controlled domestic production and export-oriented economic liberalization. Although, the traditional swidden agricultural practices of these communities required large areas of land and reduced forest cover to allow for regeneration between harvests, it also reduced reliance on the market economy to which these communities have limited access because of their economic and political marginalization.  Given the generations of traditional knowledge ethnic minority communities have of the local land and ecosystem in northwest Vietnam, it is possible that by utilizing this traditional knowledge to employ agricultural diversification and agroforestry practices ethnic minority communities can utilize increased forest cover and decrease reliance on the state and market, while also increasing their food security overall.  In this paper, I will explore the relationship between forests, biodiversity. and food security by examining the socio-economic impact of land cover and land use change on rural ethnic minority communities in northwest Vietnam, and alternative strategies utilizing agrobiodiversity to improve their food security while also maintaining forest cover.

Land Use and Land Cover Change in Northwest Vietnam

In the Hoang Lien Son Mountains of northwestern Vietnam lives a population of just over 11.05 million people, of which 55 percent identify as an ethnic minority, a majority of which are Hmong.   These rural ethnic minority groups are geographically-dispersed, politically-fragmented, economically marginalized, and lineage-based.   Most of the members of these communities remain in their resident villages and maintain mostly subsistence agricultural livelihoods.   The mountain range is also home to the highest peak in the Indochina region, Mount Fansipan, at 3,431 meters, experiences a subtropical climate, is characterized by steep slopes, limestone karsts, diverse flora and fauna, and depending on the altitude, contains tropical evergreen forest, Elfin-Moss forest, woody secondary vegetation, low grass savanna, and high montane flora.

In the mid-1980s, Vietnam shifted from a state-controlled economy to a market-based economy, transforming agricultural production from publicly-owned cooperatives to privately owned export-oriented commercial production, although the majority of land remained under the control of smallholder farmers who focused mainly on subsistence production.   Before the mid-1990s, many of the rural farmers practiced a composite agricultural system, including swidden agriculture, cultivating multiple rotating plots to allow regeneration between harvests.   Over generations, these farmers have bred traditional seed varieties best adapted to the steep limestone-dotted hills of the area, often cultivating small patches of soil along the rocky hillsides.   Although swidden agriculture requires a large area of land in order to efficiently rotate cultivation, it also allows for agricultural diversification and utilizes natural ecosystem succession to restore functionality and diversity after harvest instead of requiring external fertilizers and pest control methods.  This system gave farmers direct control over their food source and required minimal cash investment, likely payable after harvest.  However, their food supply was limited by available land and weather fluctuations.

As Vietnam shifted to a market economy in the mid-1980s, the state prioritized reforestation and forest protection, officially classifying forests for production, such as timber production, protection, around watersheds for example, and special-use, as in national parks and reserves.   The subsequent policies designated production and protection forest allocations to households, specified limitations on agriculture, logging, and nontimber forest product (NTFP) forage in forest lands, and provided interest-free loans to households who converted away from swidden agriculture.   These policies forced rural households to abandon swidden plots in favor of intensive monocultures for subsistence, and to rely more heavily on markets for both agricultural inputs and formally foraged goods.   Many immigrant households in the lower altitudes turned toward production forests and converted their land to cash crop plantations to take advantage of growing urbanization and trade, whereas traditional ethnic households in the higher altitudes supplemented subsistence farming with cardamom cultivation in the underbrush of protected forests for export to Chinese markets.   In order to facilitate the transition away from swidden agriculture, the state distributed and subsidized hybrid rice and maize seed that would yield more crop per hectare with the input of agrochemicals.  The hybrid varieties allowed farmers to produce enough rice for their families on less land, but also made them dependent on the cash economy to finance the inputs and new seeds needed at the beginning of the planting season.   This forced households to diversify their income with wage labor and other off-farm activities in order to afford to plant the rice crop that the family relied on for sustenance throughout the year.  Thus, the nature of the food insecurity of rural ethnic communities shifted from an environmental insecurity to an economic insecurity, and while the Hmong people had learned to adapt and utilize environmental challenges to their advantages, the economic challenges are new, foreign, and politically manufactured.

Forests and Biodiversity

Biodiversity usually increases ecosystem productivity and stability by increasing the probability that a disruption in one species or function will be compensated by another through increased biomass production, and counter-balancing fluctuations in species functions populations.   More biodiversity also typically increases the efficiency of essential ecological functions, such as capturing resources, producing biomass, and decomposing and recycling nutrients, as different species specialize in certain functions and overlap in their capacity.   In addition, species vary in their role and impact on ecosystem productivity, so diverse communities are more likely to contain species with a large impact on productivity and species with a wider variety of functional traits in order to maximize resource use.   While biodiversity is beneficial to the maintenance of the complex interaction of all ecosystem functions, the impact of biodiversity, and any change, to humans depends on what types of services the particular ecosystem provides and how those services impact human survival.

By definition, forests contain an enormous variety of terrestrial plant and animal species all of which contribute to the maintenance of the ecosystem and provide a wide array of ecosystem services, from carbon sequestration and soil stability to food security and shelter.  Forests provide a wide variety of nutrient-rich food products that are essential to maintaining the overall health of rural communities, which can be lost when forests are cleared for monoculture production of staple crops, resulting in micronutrient deficiencies.   These products are often also culturally valued and provide a safety net during times of food stress, while forest timber is of course essential for providing cooking fuel for these communities.   Forests can also provide stability to the surrounding landscape and agroecosystems through soil and water base maintenance, adjunct habitats for species beneficial to crop and livestock production, and increased resilience against extreme weather.   Thus, although large agricultural plots are needed to produce enough rice for the community through traditional agricultural systems, the decreased forest biodiversity caused by the deforestation necessary to cultivate various plots of agricultural land can also negatively impact the productivity of agricultural plots and the food security of local communities.

However, ad hoc reforestation does not necessarily reinstate the benefits of biodiversity previously lost through deforestation.  The degree and composition of forest biodiversity is also impacted by the density and composition of trees, and the shape and size of the forest patch and its proximity to similar forest habitats, which can vary and shift depending on the reforestation strategies used.   The density and composition of trees determine the level and type of resources available to inhabiting species and the size and characteristics of their populations.  The ecological changes that occur when forest intersects with other habitats also prevents forest-dwelling species from traveling and inhabiting the edges of the forest, which results in forests with large cohesive areas of robust and intact habitat containing more biodiversity.   Along the same lines, separate forests that are linked with transverseable patches of habitat facilitate the movement of populations between them adding to the level of biodiversity.  After the land use policy change in Vietnam, Meyfroidt and Lambin (2008) found that although forest cover increased, tree density and biomass production continued to decrease, and the forest that was regenerated was in smaller, more isolated, and oddly shaped patches, both signs of a continued decrease in forest biodiversity even after reforestation in the Hoang Lien Son Mountains.   Moreover, landscapes with a wide variety of spatial concentrations of species allow for greater stability and are especially important between large areas of monoculture   Thus, although forest cover returned to northwest Vietnam with the shift away from swidden agriculture, the benefits of biodiversity did not accompany the shift, and thus nor did the increase in food security that should come with it.

Biodiversity also has an impact on the productivity of agroecosystems.  Plant biodiversity can increase the stability and health of agroecosystems through increased resistance to invasion by exotic plants, resistance to plant pathogens, biomass production and aboveground carbon sequestration, and nutrient mineralization and organic matter in soil.   In addition, these agroecosystem services can then benefit communities through increased crop yields, wood production, fodder production, and fishery yields.   Agrobiodiversity can also help stabilize production and increase resilience against disturbances, which can protect resource-poor families from health and economic crisis.   High-yielding crops, irrigation, and agrochemical inputs can increase yields in small intensive monoculture plots in the short-term, but the practices have long-term negative consequences on human health, environmental quality, and biodiversity maintenance.   Traditional varieties, on the other hand, have been bred to survive local biotic and abiotic stresses, require few external inputs, and produce seeds that can be saved for the next season, saving farmers money, allowing for further local breeding,  and reducing negative impact on the environment.   Vlkova, et al. (2011) found that, although biodiversity was relatively low in home gardens in Vietnam, they served as local reservoirs for local food plant species and greatly contributed to the health, diet diversity, and socioeconomic stability of the family, and thus increasing their food security.

Food Security

While the Hoang Lien Son Mountains are home to a wide variety of plant and animal species, they are also home to a wide variety of ethnic communities.  The Kinh people comprise the majority of the population in Vietnam, however, they only account for 45 percent of the population and mainly inhabit the low altitude and urban areas of this mountainous region.  The other 55 percent of the population consists of a mix of the 53 ethnic minority groups in Vietnam, with Hmong people dominating the higher altitude rural villages.   The political evolution of Vietnam has resulted in a degree of social and economic disparity between the Kinh and Hmong people, with the Kinh having much greater opportunities for economic growth and education through traditional cultural networks.  Thus, while the Kinh rely mostly on the provision of goods and services, or commercial agriculture for their livelihoods, the Hmong sustain themselves through subsistence farming, with minimal access to wage labor and trade opportunities.  In this way, the land use restrictions of the 1990s affected the food security of the Hmong people in different ways than it did the Kinh.

While the Kinh relied more on state-sponsored reforestation programs to establish production forest for commercial means, the Hmong relied on their cultural understanding of watershed protection and local species to utilize protected and special-use forest for the forage of NTFPs.   This diversion in livelihood strategy can partly be explained by the migration of Kinh from coastal cities to the upland valleys in the 1960s to work on state and private timber companies, whereas the Hmong have inhabited the mountains of southern China and northern Vietnam and Cambodia for centuries.  Thus, the Hmong have developed extensive traditional knowledge and cultural connections to the local landscape and ecology.  When the government restricted their ability to practice traditional agriculture systems, the Hmong utilized their extensive knowledge of the local food system and agricultural limits of the landscape to adapt their livelihood strategies to new state-sponsored agricultural programs and market incentives.   In their land-use land cover change maps of the region, Turner and Pham (2015) found that the Hmong were able to strategically utilize the unique landscape by cultivating small pockets of traditional maize intercropped with beans and other vegetables between the large limestone karsts along the steep hillsides.    As the Vietnamese government, however, began restricting use of such land in order to regenerate forest cover, the Hmong were forced to adopt hybrid seeds and intensive monocultures to grow enough food on their reduced agricultural allotments.  In order to meet the cash demand of additional inputs needed for hybrid seeds, Hmong were forced to diversify their livelihoods off-the-farm and often turned toward NTFPs of protected and special-use forests, to trade or sell at market and maintain their food security.

Due to land-use restrictions, farmers have resorted to intensification and on-farm diversification options, which are limited in the uplands by the low availability of low slope and low elevation regions, requiring them to increasingly draw on hybrid seeds and agrochemical inputs.    Although hybrid seeds often produce increased yields on smaller plots, these crops can actually decrease food security for resource-poor rural farmers rather than improve it because of their agroecological limits, homogeneity, and the inability of the state to distribute the appropriate quantity at the appropriate time to maximize crop yields.   In addition, the use of hybrid rice and maize seeds prevents farmers from cultivating many of the small patches of soil along the hillside because of the sloped surface, and requires farmers to have access to more cash for inputs than before.   Where on-farm diversification methods are unavailable or additional diversification is needed, those that have the knowledge and access, have chosen to cultivate cardamom under the shade of closed canopy trees in protection forests.   This too is influenced by the state in that the recent relaxation of cross-border trade regulations with China have encouraged local farmers to plant cardamom to meet the high demand for export to China.   Based on the variety of causes of land use land cover change in northwest Vietnam, Pham, et al. (2015) argue that it is imperative for the state to adapt “land use policies to local agro-ecological and socio-economic conditions and ethnic diversity, taking into account state-farmer relations, household livelihood decision-making, and policy implementation at the commune and district levels.”   Only then can state policy actually increase food security for rural ethnic minority communities.

Conclusion

Because of the complexity of ecosystem interactions and functions and the large variation between ecosystems within a state, blanket agricultural and environmental policies cannot effectively address socio-ecological problems such as biodiversity and food security.  State policy successfully expanded rice production before 1990 but also resulted in widespread deforestation.  State policy was also successful in increasing forest cover but resulted in the economic dependence of poor farmers on the cash economy for their food security.  While traditional agriculture systems required a greater area of land to be cultivated, reducing the level of forest cover, it allowed for increased agricultural diversification in cultivated plots and required less cash investment, increasing the diversity and stability of the food supply.  Other the other hand though, concentrated agrochemical intensive cultivation requires a smaller area of land, preserving forest cover, but it reduces agricultural diversification and as a result diet diversification, socio-economic stability and food security.  Either way, however, forest biodiversity appears to have declined even after reforestation, reducing its ability to contribute to the food security of ethnic minority communities.  Thus, while the Hmong experienced food insecurity before 1990 because of unequal distribution of land and access to resources, the land use restrictions in 1993, merely shifted the nature of their food insecurity towards a reliance on the market economy, mirroring the state’s shift from a state-controlled economy to an export-oriented economy.

In order to reverse the negative impact state policy has had on Hmong food security, the state needs to provide support for agricultural strategies that leverage the resources available to the Hmong, instead of strategies that conflict with those resources.  The Hmong people retain extensive knowledge about the local landscape and ecosystem that can be utilized to maximize total nutritional output within the ecological restrictions of the challenging landscape.  These communities are also experts in the medicinal and productive benefits of the local flora, which can be traded for other goods not available from the landscape.  For example, Babin (2012) found that peasants who adopted agricultural diversification strategies were able to better withstand price fluctuations than peasants that did not,  and Clough, et al. (2011) argue that wildlife-friendly farming practices can produce both high yields and high biodiversity in agroforestry ecosystems.   Because forest in northwest Vietnam provides such a wide range of ecosystem services that impact the livelihoods and food security of the marginalized local population, the value of ecosystem services provided by forests and the food security implications of land-use allocations need to be considered and compared with agricultural benefits when planning the conversion of forests into agriculture and vice versa    In addition, the valuation of ecosystem services needs to include not just their economic value, but also the multiple dimensions of ecosystem services that impact social and cultural well-being, including diet diversity and traditional knowledge.   Thus far, Hmong communities have been able to adapt their livelihoods to the changing landscape, but it is unclear how their food security will improve under current policy environment.

References

Arnold, M., B. Powell, P. Shanley, and T.C.H. Sunderland. 2011. "EDITORIAL: Forests, Biodiversity, and Food Security." International Forestry Review 13 (3): 259-264.

Babin, Nicholas L. 2012. Agrarian Change, Agroecological Transformation and the Coffee Crisis in Costa Rica. Ann Arbor, MI: ProQuest LLC.

Bandibas, M.B., and V.V. Hiloman. 2016. "Crab Biodiversity Under Different Management Schemes of Mangrove Ecosystems." Global Journal of Environmental Science Management 2 (1): 19-30. doi:10.7508/gjesm.2016.01.003.

Bassett, Thomas J. 2010. "Reducing Hunger Vulnerability Through Sustainable Development." Proceedings of the National Academy of Sciences of the United States of America (National Academy of Sciences) 107 (13): 5697-5698. http://www.jstor.org/stable/25665049.

Beckage, Brian, and Louis J. Gross. 2006. "Over-yeilding and Species Diversity: What Should We Expect." New Phytologist 172: 140-148. doi:10.1111/j.1469-8137.2006.01817.x.

Brown, Bryan L., Amy L. Downing, and Mathew A. Leibold. 2016. "Compensatory Dynamics Stablize Aggregate Community Properties in Response to Multiple Types of Perturbations." Ecology (Ecologist Society of America) 97 (8): 2021-2033.

Cardinale, Bradley J., Emett Duffy, Andrew Gonzalez, and et al. 2012. "Biodiversity Loss and Its Impact on Humanity." Nature (Macmillan Publishers Limited) 486: 59-67.

Carrasco, L. R., S. A. Papworth, J. Reed, W. S. Symes, A. Ickowitz, T. Clements, T. Sunderland, and K. S.-H. Peh. 2016. "Five Challenges to Reconcile Agricultural Land Use and Forest Ecosystem Services in Southeast Asia." Conservation Biology (Society for Conseervation Biology) 30 (5): 962-971. doi:10.1111/cobi.12786.

Clough, Yann, Jan Barkmann, Jana Juhrbandt, Michael Kessler, Thomas Cherico Wagner, Alam Anshary, Damayanti Buchori, et al. 2011. "Combining High Biodiversity with High Yields in Tropical Agroforests." Proceedings of the National Academy of Sciences of the United States of America (National Academy of Sciences) 108 (20): 8311-8316. http://www.jstor.org/stable/25830047.

Dawe, D. 2002. "The Changing Structure of the World Rice Market, 1950-2000." Food Policy (Elsevier Science Ltd.) 27: 355-370.

Farmar-Bowers, Quentin. 2014. "Food Security: One of a Number of "Securities" We Need for a Full Life: An Australian Perspective." Journal of Agricultural Environmental Ethics (Springer Science) 27: 811-829. doi:10.1007/s10806-014-9491-1.

Fischer, Joern, David B. Lindenmayer, and Adrian D. Manning. 2006. "Biodiversity, Ecosystem Function, and Resilience: Ten Guiding Principles for Commodity Production Landscapes." Frontiers in Ecology and the Environment (Wiley) 4 (2): 80-86. http://www.jstor.org/stable/3868711.

Frison, Emile A., Jeremy Cherfas, and Toby Hodgkin. 2011. "Agricultural Biodiversity is Essential for a Sustainable Improvement in Food and Nutrition Security." Sustainability 3: 238-253. doi:10.3390/su3010238.

Garaway, Caroline Jane, Chantone Photitay, Khampet Roger, Lieng Khamsivilay, and Matthias Halwart. 2013. "Biodiversity and Nutrition in Rice-Based Ecosystems: The Case of Lao PDR." Human Ecology (Springer Science) 41: 547-562. doi:10.1007/s10745-013-9602-z.

Gunderson, Lance H. 2000. "Ecological Resilience: In Theory and Application." Annual Review of Ecology and Systematics (Annual Reviews) 31: 425-439. http://www.jstor.org/stable/221739.
Jackson, L. E., U. Pascual, and T. Hodgkin. 2007. "Utilizing and Conserving Agrobiodiversity in Agricultural Landscapes." Agriculture, Ecosystems, and Environment (Elsevier) 121: 196-210.

Jacobi, Johanna. 2016. "Agroforestry in Bolivia: Opportunities and Challenges in the Context of Food Security and Food Sovereignty." Environmental Conservation (Foundation for Environmental Conservation) 43 (4): 307-316.

Laurance, William F., and Eric Yensen. 1991. "Predicting the Impacts of Edge Effects in Fragmented Habitats." Biological Conservation (Elsevier Science) 55: 77-92.

Lhomme, Jean-Paul, and Thierry Winkel. 2002. "Diversity-Stability Relationships in Community Ecology: Reexamination of the Portfolio Effect." Theoretical Population Biology (Elsevier Science) 62: 271-279. doi:10.1006/tpbi.2002.1612.

Liang, Jingjing, and et al. 2016. "Positive Biodiversity-Productivity Relationship Predominant in Global Forests." Science 354 (6309): aaf8957. doi:10.1126/science.aaf8957.

Mayer, Philipp. 2006. "Biodiversity: The Appreciation of Different Thought Styles and Values Helps to Clarify the Term." Restoration Ecology (Society for Ecological Restoration International) 14 (1): 105-111.

Meyfroidt, Patrick, and Eric F. Lambin. 2008. "Forest Transition in Vietnam and its Environmental Impacts." Global Change Biology 14: 1319-1336. doi:10.1111/j.1365-2486.2008.01575.

Michler, Jeffrey D., and Anna J. Josephson. 2017. "To Specialize or Diversify: Agricultural Diversity and Poverty Dynamics in Ethiopia." World Development (Elsevier Ltd.) 89: 214-226.

Pardy, Bruce. 2014. "The Logic of Ecosystems: Capitalism, Rights and the Law of 'Ecosystem Services'." Journal of Human Rights and the Environment (Edward Elgar Publishing, Ltd.) 5 (2): 136-152.

Pham, Thi-Thanh-Hien, Sarah Turner, and Kate Trincsi. 2015. "Applying a Systematic Review to Land Use Land Cover Change in Northern Upland Vietnam: The Missing Case of the Borderlands." Geographical Research 53 (4): 419-435.

Pickett, S.T.A., and M.L. Cadenasso. 1995. "Landscape Ecology: Spatial Heterogeneity in Ecological Systems." Science (American Association for the Advancement of Science) 269 (5222): 331-334.

Poole, Nigel, Camilla Audia, Bartelemy Kaboret, and Rebecca Kent. 2016. "Tree Products, Food Security and Livelihoods: A Household Study of Burkina Faso." Environmental Conservation (Foundation for Environmental Conservation) 43 (4): 359-367. doi:10.1017/S0376892916000175.

Purvis, Andy, and Andy Hector. 2000. "Getting the Measure of Biodiversity." Nature (Macmillan Magazines Ltd) 405: 212-219.

Rahman, Syed Ajijur, Terry Sunderland, Mrigesh Kshatriya, James M. Roshetko, Tim Pagella, and John R. Healey. 2016. "Toward Productive Landscapes: Trade-offs in Tree Cover and Income Across a Matrix of Smallholder Agricultural Land Use Systems." Land Use Policy (Elsevier Ltd.) 58: 152-164.

Ramprasad, Vanaja. 1994. "Conserving Biodiversity." Economic & Political Weekly 29 (43): 2795-2797. http://www.jstor.org/stable/4401934.

Read, Rupert, and Molly Scott Cato. 2014. "'A Price for Everything': The 'Natural Capital Controversy'." Journal of Human Rights and the Environment (Edward Elgar Publishing, Ltd.) 5 (2): 153-167.

Reid, Colin T., and Walters Nsoh. 2014. "Whose Ecosystem is it Anyway? Private and Public Rights Under New Approaches to Biodiversity Conservation." Journal of Human Rights and the Environment (Edward Elgar Publishing Ltd.) 5 (2): 112-135.

Ribeiro, Paulo Flores, Jose Lima Santos, Joana Santana, Luis Reino, Pedro Beja, and Francisco Moreira. 2016. "An Applied Farming Systems Approach to Infer Conservation-Relevant Agricultural Practices for Agri-Environment Policy Design." Land Use Policy 58: 165-172.

Risvoll, Camilla, Gunn Elin Fedreheim, and Diego Galafassi. 2016. "Trade-offs in Pastoral Governence in Norway: Challenges for Biodiversity and Adaptation." Pastoralism: Research, Policy, and Practice (Springer) 6 (4): 1-15. doi:10.1186/s13570-016-0051-3.

Schulp, C.J.E., A.J.A. Van Teeffelen, G. Tucker, and P.H. Verburg. 2016. "A Quantitative Assessment of Policy Options for No Net Loss of Biodiversity and Ecosystem Services in the European Union." Land Use Policy 57: 151-163.

Sobey, R. T. 1997. "Biodiversity Value of Hoang Lien Mountatins and Strategies for Conservation." Proceedings of Seminar and Workshop, Frontier-Vietnam in conjunction with the Institute of Ecology and Biological Resources, Sa Pa District, Lao Cai Province, Vietnam.

Sunderland, T.C.H. n.d. "Food Security: Why is Biodiversity Important?" International Forestry Review (Commonwealth Forestry Association) 13 (3): 265-274. http://www.bioone.org/doi/full/10.1505/146554811798293908.

Thanh, Hoang Xuan, Truong Tuan Anh, Luu Trong Quang, Dinh Thi Giang, and Dinh Thi Thu Phuong. December 2013. Food Security in the Context of Vietnam's Rural-Urban Linkages and Climate Change. Country Report, International Institute for Environment and Development, London, UK: CGIAR Research Program on Climate Change, Agriculture and Food Security.

Trincsi, Kate, Thi-Thanh-Hien Pham, and Sarah Turner. 2014. "Mapping Mountain Diversity: Ethnic Minorities and Land Use Land Cover Change in Vietna's Borderlands." Land Use Policy (Elsevier Ltd.) 41: 484-497.

Trinh, L.N., J.W. Watson, N.N. Hue, N.N. De, N.V. Minh, P. Chu, B.R. Sthapit, and P.B. Eyzaguirre. 2003. "Agrobiodiversity Conservation and Development in Vietnamese Home Gardens." Agriculture, Ecosystems and Environment (Elsevier Science) 97: 317-344. doi:10.1016/S0167-8809(02)00228-1.

Turner, Sarah, and Thi-Thanh-Hien Pham. 2015. ""Nothing Is Like It Was Before": The Dynamics Between Land-Use and Land-Cover, and Livelihood Strategies in the Northern Vietnam Borderlands." Land 4: 1030-1059.

Vlkova, Martina, Zbynek Polesny, Vladimir Verner, Jan Banout, Marek Dvorak, Janoslav Havlik, Bohdan Lojka, Petr Ehl, and Jitka Krausova. 2011. "Ethnobotanical Knowledge and Agrobiodiversity in Subsistence Farming: Case Study of Home Gardens in Phong My Commune, Central Vietnam." Genetic Resource Crop Evolution (Springer Science) 58: 629-644. doi:10.1007/s10722-010-9603-3.

Zimmerer, Karl S. 2013. "The Compatibility of Agricultural Intensification in a Global Hot Spot of Smallholder Agrobiodiversity (Bolivia)." Proceedings of the National Academy of Sciences of the United States of America (National Academy of Sciences) 110 (8): 2769-2774. doi:http://www.jstor.org/stable/42583128.