LAND
COVER CHANGE AND DEFORESTATION IN CENTRAL AMERICA
1990-2008
Emil A. Cherrington Betzy E. Hernández Bessy C. García Marcelo O. Oyuela Antonio H. Clemente Water Center for the Humid Tropics of Latin America & the Caribbean (CATHALAC) 111 City of Knowledge, Panama City, Panama TEL: (507) 317-3200 • servir@cathalac.org May 2011
LAND
COVER CHANGE AND DEFORESTATION IN CENTRAL AMERICA
1990-2008
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LAND COVER CHANGE AND DEFORESTATION IN CENTRAL AMERICA, 1990-2008
INTRODUCTION Deforestation in Central America drew attention from the international media in the 1980s, when awareness of deforestation in tropical countries eventually led to the development of novel conservation mechanisms like Debt-for-Nature Swaps which sought to provide financial incentives for environmental conservation (Nations & Leonard 1986, Muller 2003). Nations & Leonard (1986) had estimated that from the 1960s through the mid-1980s, over twothirds of Central America’s lowland tropical broadleaf forests had been decimated, and the Food & Agriculture Organization of the United Nations (FAO 2000) would later affirm that the region’s deforestation rates would continue to be high in the following decade. In the second decade of the third Millennium, deforestation in tropical nations has once again taken the forefront, with the development of the initiative known as Reducing Emissions from Deforestation & Forest Degradation, REDD+. REDD+ seeks, eventually via international markets for the trading of carbon dioxide emission offsets, to provide financial incentives for tropical, forested nations to conserve their forest ecosystems. A key input to the development of REDD+ is information on rates of deforestation and forest degradation in participating countries. Where, in 2011, various countries in Central America and the Dominican Republic are participating in mechanisms such as the World Bank’s Forest Carbon Partner-
ship Facility (FCPF), UN-REDD, and a GIZ (formerly GTZ)-funded project with the Central American Commission for the Environment and Development (the REDD CCAD GIZ project), since 2005, the technical groundwork for REDD+ implementation has been lain by the Regional Visualization & Monitoring System (SERVIR). SERVIR was established at the Water Center for the Humid Tropics of Latin America and the Caribbean (CATHALAC) in February 2005, through the financial and technical support and collaboration of the U.S. Agency for International Development (USAID), and NASA. The system has given the broader Mesoamerican and Caribbean region with its first ever system for monitoring the region’s skies, seas, and land, using satellites. The system has also been recognized as a key step in the implementation of the Global Earth Observation System of Systems (GEOSS). SERVIR provides decision-makers, researchers, students, and the general public with daily observations and forecasts pertaining to the atmosphere, and terrestrial and marine environments. Of specific relevance to REDD+, SERVIR has provided capacity-building for determining land cover and land cover change, as well as the inputs to such assessments (the region’s largest catalog of satellite data), as well as having itself derived land cover products for assessing regional trends. The current study presents a review and summary of land cover change in Central America.
LAND COVER CHANGE AND DEFORESTATION IN CENTRAL AMERICA, 1990-2008
OBJECTIVES The overarching objective of this study is to report on land cover change, particularly deforestation within Central America over the eighteen periods spanning 1990 to 2008. The principal reason for choosing the 1990 to 2008 timeframe is the availability of comparable data for that period. Mechanisms like the Clean Development Mechanism of the United Nations Framework Convention on Climate Change (UNFCCC) – the sister mechanism to REDD+ - also focus on 1990 as a baseline for reforestation activities, so 1990 is also an appropriate choice.
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LAND COVER CHANGE AND DEFORESTATION IN CENTRAL AMERICA, 1990-2008
METHODOLOGY This study reviews existing data on land cover in Central America to draw conclusions on land cover change. Where necessary, land cover data from the original sources had to be adjusted for the sake of comparability, as studies realized at different dates often use different methodologies for identifying land cover types, as well as different definitions of certain land cover types. Where some take this to mean that land cover datasets are not comparable between projects, the authors of this paper take the view that data can indeed be harmonized for comparison. In terms of data review, data was first compiled from numerous sources (Table 1). It can be observed that over fourteen separate global and regional initiatives, some thirty-one land cover related datasets were produced either for or including Central America. Almost all of the datasets in the list were accessible, except for the as-yetunreleased European Commission-supported Regional Disaster and Environmental Vulnerability Prevention (PREVDA) 19802010 land cover data, and the recent 2007 and 2009 global forest cover maps from JAXA. Another key observation is that with the exception of the forthcoming PREVDA land cover products, none of the datasets presented have been validated for Central America, meaning the accuracy of these may be in question.
Following careful analyses of the various datasets, the ones viewed as most adequate for this study’s purpose were 500m-resampled versions of the 30m land cover data from EarthSat Inc.’s GeoCover LC project. The resampling had actually been done by the University of Arkansas’ Center for Advanced Spatial Technology (CAST) in the context of the SERVIR project in 2006. That data had also been derived – along with other MODIS-based land cover maps developed by CAST – specifically for the purposes of greenhouse gas emissions, which thus has synergies with the current study. CAST had also aggregated the data from its original 15-classes into six classes: forest, cropland, grassland, wetland, urban areas, and other land cover types. For assessment of land cover change through to the closest date to the present (i.e. 2011), the 2008 land cover dataset released by the European Space Agency’s DIVERSITY project was chosen. At 300m in resolution, it could be resampled to compare to that of the resampled GeoCover LC dataset, and its classes as well as its method of generation were similar to that of GeoCover LC. In terms of further analyses, classes were aggregated by CATHALAC to be comparable to the sixclass GeoCover LC dataset. Results, focusing on deforestation and reforestation, were then derived from comparison of the 1990, 2000, and 2008 data.
LAND COVER CHANGE AND DEFORESTATION IN CENTRAL AMERICA, 1990-2008
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Table 1. Land cover datasets with coverage of Central America (source: compilation by the authors) Date - Ground
Date -
Condition
Publication
No.
Dataset
1
Land cover Land cover Land cover Land cover
c. 1990, c. 2000 1992-1993
2005
1981-1994
1998
1992-1993
1998
5
Tree cover
1992-1993
2000
University of Maryland
6
Land cover
1991-1999
2002
World Bank
7
Land cover Land cover Tree cover
2000
2002
JRC
2000, 2005, 2007, 2008 2000, 2001, 2002, 2003, 2004, 2005 2000, 2003, 2004, 2005 2005
2008
ESA / GeoVille
2008
University of Maryland
2006
University of Arkansas Giri & Jenkins
2004-2006, 2009 2007, 2009
2008
1980, 1990, 2000, 2010
2011
2 3 4
8 9
10 11 12 13 14
Land cover Land cover Land cover Forest cover Land cover
1999
2005
2010
Original Source
Source
Imagery Used
Earth Satellite Corporation USGS
GeoCover LC 1990 GLCC
Landsat TM
30m
global
15
AVHRR
1km
global
100
University of Maryland PROARCA / CAPAS
GLCC
AVHRR
1km
global
14
Central American Vegetation/ Land Cover Classification and Conservation Status Tree Cover Continuous Fields Central America Ecosystem Mapping Project GLC 2000
AVHRR
1km
regional
24
AVHRR
1km
global
3
Landsat TM
30m
regional
197
SPOT Vegetation MODIS
1km
global
23
500m
regional
13
MODIS
500m
global
3
MODIS
500m
regional
6
MODIS
500m
regional
9
MERIS
300m
global
17
ALOS PALSAR MODIS
10m
global
2
250m
regional
16
DIVERSITY project MOD44B
SERVIR MesoClass
ESA / MEDIAS GlobCover France project JAXA CATHALAC / PREVDA
PREVDA project
resolution
Coverage
No.
Published as
classes
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LAND COVER CHANGE AND DEFORESTATION IN CENTRAL AMERICA, 1990-2008
RESULTS & DISCUSSION In ~1990, forests made up approximately 269,296 km² or 52% of Central America’s land cover, while in 2008, that figure was approximately 241,073 km² or 46.5% of the region’s land cover. Figure 1 displays the comparison of the circa 1990 land cover data with the 2008 land cover data. These results would indicate that Central America lost some 74,162 km² of forest between 1990 and 2008, but that within the same period, some 45,939 km² of tree cover (though not necessarily forest) had grown up. As such, the region’s net deforestation would be in the order of some 28,223 km² over the
eighteen year period, or a net annual loss of approximately 1,568 km² of forest- 0.58%. It should be noted that such a figure exceeds, for instance, the size of either of Central America’s smallest nations, El Salvador (~20,000 km²) or Belize (~23,000km²). The data also indicate that another 16,646 km² of other types of vegetation (e.g. shrubland and wetlands) had been cleared, largely for agricultural activities, though apparently an almost equal area – 16,629 km² of vegetation had grown up in areas previously identified as cultivated land. Taking all these
Figure 1. Land cover change in Central America, circa 1990-2008
LAND COVER CHANGE AND DEFORESTATION IN CENTRAL AMERICA, 1990-2008
figures together, this would indicate that land cover change within Central America is a dynamic process, although various caveats apply to this analysis. For one, the ultimate accuracy of the datasets used is unknown, so it is difficult to verify whether reversions in land cover – or outright changes have occurred, although they do seem to concur with other datasets at hand. For instance, Figure 2 shows an analysis based on 1km (coarse) resolution MODIS Leaf Area Index data indicating whether vegetation has either been cleared or has been regrown. As can be seen from comparison of Figures 1 and 2, there is general agreement between
the areas shown as deforested and the areas where biomass loss is indicated. The difficulty in comparing the two figures is the resolution, the time-frame, and the difference of the products off which they are based. For instance, areas with loss of biomass in Figure 2 will likely include agricultural areas which have switched to lower biomass crops over the nine year span (i.e. loss of average biomass does not necessarily equal deforestation). In fact, Figure 2 might also include areas where forest types have been degraded, another component of REDD+. In any event, the best available data indicate that deforestation in Central America between 1990 and 2008 was high.
Figure 2. Change in leaf area index, 2000-2009 (source: analysis of NASA MOD15 data)
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LAND COVER CHANGE AND DEFORESTATION IN CENTRAL AMERICA, 1990-2008
CONCLUSIONS The preliminary conclusion of this paper – with a perspective on Central America’s emerging participation in conservation mechanisms such as REDD+ - is that over the eighteen years spanning 1990 to 2008, Central America had a net deforestation of some 28 thousand square kilometers, or an annual loss of some 1,568 km² (a net annual deforestation rate of 0.58%). The best available data indicate that actual deforestation was higher (~74,000 km²), but that this was
somewhat counter-acted by reforestation (~46,000 km²). It will be useful to see, for instance, how this assessment compares to the soon to be released thirty-year (19802010) land cover change study conducted under the auspices of the Regional Disaster and Environmental Vulnerability Prevention (PREVDA) project, which, unlike prior studies, has validated its results with data from field surveys.1
ACKNOWLEDGEMENTS This work was supported under NASA Contract No. NNM07AB02C with CATHALAC, through the generous support of the U.S. Agency for International Development (USAID). In particular, Carrie Stokes, Orlando Altamirano, Ruben Aleman, and Michelle Jennings of USAID must be acknowledged. CATHALAC Director Emilio Sempris, NASA Earth Science Division Director Michael Freilich, NASA
1 The 1999-2002 World Bank and Government of the Netherlands-supported Central America Ecosystems Mapping Project also collected field data, but the results of those field surveys was not used to validate the project’s outputs.
Program Scientist for Biological Diversity and Program Manager for Ecological Forecasting Woody Turner, NASA SERVIR Project Director Daniel Irwin, and NASA SERVIR International Programs Director Gwendolyn Artis must also be acknowledged for their support, as should Eric Anderson and Africa Flores of the University of Alabama-Huntsville.
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REFERENCES Anderson, E.R., Cherrington, E.A., Tremblay-Boyer, L., Flores, A.I, and E. Sempris. 2008. “Identifying Critical Areas for Conservation using measures of Biodiversity and Climate Change in Central America, Mexico, and the Dominican Republic.” Biodiversity 9 (3 & 4): 89-99 Barry, P.L. 2003. “Mesoamerica Burning.” Science@NASA. National Aeronautics and Space Administration. Washington, DC. Available online: http://science.nasa.gov/headlines/y2003/16may_biocorridors.htm Conservation International (CI). 2006. “Biodiversity Hotspots: Mesoamerica.” Center for Applied Biodiversity Science. Washington, DC. Available online: http://www.biodiversityhotspots.org/xp/hotspots/mesoamerica/Pages/biodiversity.aspx Food & Agriculture Organization (FAO). 2000. “Annotated Bibliography: Forest Cover Change: Belize.” Working Paper 40. Rome, Italy. 36 pp. Available online: http://www.fao.org/docrep/007/ad677e/ad677e00.htm Global Observation of Forest and Land Cover Dynamics (GOFC-GOLD) Secretariat. 2009. “A Sourcebook of Methods and Procedures for Monitoring and Reporting Anthropogenic Greenhouse Gas Emissions and Removals caused by Deforestation, Gains and Losses of Carbon Stocks in Forests remaining Forests, and Forestation.” GOFC-GOLD Report version COP15-1. Alberta, Canada. 197 pp. Lillesand, T.M., Kiefer, R.W., and J.W. Chipman. 2007. Remote Sensing & Image Interpretation. Sixth Edition. Wiley & Sons. 756 pp. Nations, J. & H.J. Leonard. 1986. “Grounds of Conflict in Central America.” pp. 55-100 in: Maguire, A. & J.W. Brown (eds.) 1986. Bordering on Trouble: Resources and Politics in Latin America. Adler & Adler: Bethesda, MD. 464 pp.
Sader, S.A., Hayes, D.J., Irwin, D.E., and S.S. Saatchi. 2001. “Preliminary Forest Cover Change Estimates for Central America (1990’s), with Reference to the Proposed Mesoamerican Biological Corridor.” Proceedings of the Year 2001 Annual Conference of the American Society of Photogrammetric Engineering and Remote Sensing. St. Louis, MO. 11 pp. Vreugdenhil, D., Meerman, J., Meyrat, A., Gómez, L.D., and D.J. Graham. 2002. “Map of the Ecosystems of Central America: Final Report.” World Bank, Washington, DC. 56 pp.
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