Home -- Carlos Mena Ongoing & past projects, papers, and proposals
				§ Drivers of land use and land cover change in the Ecuadorian Amazon § People and protected areas: the case of the Cuyabeno Reserve § Secondary forest succession in the Ecuadorian Amazon § Remote Sensing of tropical environments § Invasive species in Galapagos § Coupled human-natural systems and complex systems in the Galapagos Islands § Agent based model and cellular automata in the Northern Ecuadorian Amazon § Geography (the discipline) in Ecuador Drivers of land use and land cover change in the Ecuadorian Amazon Mena CF, Bilsborrow RE, McClain ME (2006). Socioeconomic Drivers of Deforestation in the Northern Ecuadorian Amazon. Environmental Management 37(6): 802-815. Investigations of land use, land cover change, and forest management are limited by a lack of understanding of how socioeconomic factors affect land-use. This also makes difficult to predict future deforestation which is, especially important in the Amazon basin where large tracts of natural forest are being converted to managed uses. The objectives of this research are (a) to quantify deforestation in the Napo River Basin of Ecuador and (b) to determine the significance and magnitude of the effects of socioeconomic factors on deforestation rates at both the parroquia (parish) and finca (farm) levels. Annual deforestation rates between 1986 and 1996 were quantified via satellite image processing and geographic information systems. Linear regression analyses were used to explore relationships between socioeconomic factors and deforestation. Socioeconomic factors were obtained, at the finca level, from a detailed socioeconomic survey executed in 1990 for 167 households, and at the parroquia level using the 1990 Ecuadorian National Census. The research results show that the average annual deforestation rate was 1.24 % in the study area. At both scales, variables representing demographic factors, road accessibility, education, and poverty were significantly related to deforestation. These findings demonstrate both the severity of deforestation in the Northern Ecuadorian Amazon and the multitude of factors affecting deforestation in the tropics. [top of the page] People and protected areas: the case of the Cuyabeno Reserve Mena CF, Barbieri A, Walsh SJ, Erlien CM, Bilsborrow RE, Lu F (2006). Pressure on the Cuyabeno Wildlife Reserve: Development and Land Use/Cover Change in the Northern Ecuadorian Amazon. World Development 34(10): 1831-1849. Development and land use/landcover (LULC) change have altered the landscape in and around the Cuyabeno Wildlife Production Reserve in the Northern Ecuadorian Amazon (NEA). Today, the Reserve covers approximately 600,000 hectares and is home to a host of endemic plants and animals as well as ancestral territories of indigenous groups, including the Cofán, Siona, Secoya, and Quichua. This study examines demographic and socioeconomic drivers of LULC change in and around the Reserve drawing upon a number of primary sources of data, including household surveys and a satellite image time-series. We find that LULC patterns within and adjacent to the Reserve are influenced by: (1) changes in land tenure regimes in newly classified Patrimony Forest, (2) petroleum exploration and production, (3) indigenous communities location, characteristics, and integration to the market economy, and (4) settlement patterns and household characteristics of colonists. Statistical analyses suggest the number of children in the household, the use of hired labor, and geographic accessibility are important factors in explaining variations in the extent of deforestation on household farms in the Patrimony Forest. [top of the page] Secondary forest succession in the Ecuadorian Amazon Mena CF, Walsh SJ, Bilsborrow RE (In Review). Socioeconomic and Demographic Drivers of Secondary Forest Regeneration in the Northern Ecuadorian Amazon, Regional Environmental Change. Secondary forests and fallow in the Northern Ecuadorian Amazon (NEA) are land use/land cover types positioned along an ecological gradient from primary forest to barren land that have implications for the sustainable management of forest ecosystems and the nature of the interactions between people and the environment. The NEA is a frontier region primarily transformed through household decisions at the farm-level regarding deforestation and agricultural extensification practices. Land conversion outcomes that result from household decisions are influenced by a complex set of exogenous and endogenous variables that include socio-economic, demographic, and geographic factors that contribute to the generation and retention of secondary forest and early successional vegetation (i.e., fallow or rastrojo). The objectives of this paper are (a) to quantify the extent of secondary forest and fallow at the regional level between 1986 and 2002 and (b) to analyze the socioeconomic, demographic, and biophysical factors that contribute to the generation of secondary successional vegetation at the farm-level in 1990 and in 1999. This study uses satellite image processing to find the proportion of secondary forest in the NEA and logistic regression to study the effects of farm characteristics on successional vegetation. In the case of the statistical analysis, the dependent variable and the independent variables are obtained from the longitudinal household survey. Results show different combinations of factors contribute to the generation of secondary in the two selected years. Accessibility, title over the farm, good soils, and age of the head of household are significant for 1990, while off-farm employment, years since settlement, education, accessibility, and proportion of forest in early years contribute to the probability of secondary forest in 1999. The research design and analysis draws upon the theory of population-environment interactions within a frontier setting. [top of the page] Remote Sensing of tropical environments Land use and land cover trajectories in the Northern Ecuadorian Amazon (Dissertation Chapter…coming soon). [top of the page] Invasive species in the Galapagos Islands With Steve Walsh, Amy McCleary, Yang Shao and Julie P. Tuttle Using satellite image data and field data collected in the spring and summer of 2006 for test sites on Isabela Island, the composition and spatial structure of Guayaba are examined through the following approaches: (1) hyper-spatial and multi-spectral QuickBird data were examined through a traditional pixel-based classification approach, as well as an object-based image analysis (OBIA) approach to characterize Guayaba patterns throughout the study area; (2) Hyperion hyper-spectral data were assessed using the Minimum Noise Fraction (MNF) and Pure Pixel Index (PPI) to examine the spectral characteristics of Guayaba, and to link that knowledge to the classified QuickBird data (4 x 4-m) to characterize spectral endmembers for “unmixing” the 30 x 30-m Hyperion data using linear and non-linear modeling approaches; (3) image classifications of Guayaba, generated through pixel-based and object-based approaches, as well as spectral unmixing (i.e., percent Guayaba for each pixel) approaches were compared through the use of ecological pattern metrics to describe the spatial structure of Guayaba. Patch size, patch density, area, and contagion landscape metrics were interpreted to consider management strategies for the eradication of Guayaba and the restoration of native and endemic habitats in the Galapagos National Park and throughout the archipelago. [top of the page] Coupled human-natural systems and complex systems In the Galapagos Islands: With Steve Walsh, Ron Rindfuss, Flora Lu (proposal) Our primary aim is to develop a data-informed, agent-based model that allows us to understand the implications of alternative conservation and development scenarios in the Galapagos Islands, with an emphasis on the three main populated islands of Santa Cruz, San Cristobal, and Isabela. To avoid having the model rest on rules and relationships that are not empirically grounded, there are additional specific aims to provide descriptive information on the (1) demographic system, (2) socio-economic system, (3) ecological system, and (4) the interrelationships and feedbacks among them. Complexity theory and Agent Based Models are used to integrate the endogenous and exogenous factors and their feedbacks among the three systems so that we can examine conservation vs. development scenarios. In the Amazon: Walsh SJ, Malanson GP, Messina JP, Mena CF (In Review). Complexity and Land Use Dynamics in the Northern Ecuadorian Amazon, GeoForum. Walsh SJ, Brown D, Messina JP, Mena CF (In Press) “Complexity and Biogeography” Handbook of Biogeography [top of the page] Cellular Automata and Agent Based Models (AMB) in the Northern Ecuadorian Amazon With Steve Walsh, Brian Frizzelle, Xiaozheng [top of the page]