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Description: Building on 33 years of research experience in the Amazon, this study will advance our understanding of land cover and land use change (LCLUC) and what trajectories will lead the region towards a sustainable path in both social and environmental terms. This project builds on a seven-region study, along the LBA transects, supported for nine years by NSF, NOAA and NIH funding, and for the past seven years by LBA funds. In this final phase of LBA, we propose to upscale from our detailed studies of human-environment interactions at these seven sites by examining LCLUC dynamics at county level in a total of 135 municipios, then aggregate these municipios data into two meso-regions, one in Para (ca. 672,200 km2), and the other in Rondonia (ca. 130,479 km2), and then to the entire two states (1,239,800 km2 and 239,400km2 respectively) to achieve our goals. We take advantage of data collected for several years using a nested-georeferenced approach including soil analyses, vegetation stand structure and composition (100+ sites), land use histories, institutional analyses, demography of 900+ households, and land cover classification using multi-temporal remote sensing data since 1970. The seven regions in our study represent a soil fertility gradient across Amazonia from most (i.e. alfisols) to least (i.e. spodosols) fertile and include a wide array of landscapes being transformed by human action along an east-to-west transect, extending from the Amazon estuary and the Bragantina region east of Belem, all the way to Rondonia in the west. To achieve NASA/LBA goals towards synthesis and integration, we propose:

1. Developing a multi-scale synthesis of LCLUC dynamics. We will do so by scaling up from our seven study areas to Census units such as municipalities, and meso-regions (contiguous groups of municipalities) several orders of magnitude larger than 10,000 km2. At each level we will be seeking to understand the role of social and biophysical variables on LCLUC trajectories during the past 30 years at scales at which concepts regarding sustainability can be applied and measured. Of interest are questions about Amazonian carbon dynamics at these scales and how human populations in our study areas are responding, for instance to initiatives prompted by the Kyoto Protocol and by Proambiente in Brazil. Our focus on sustainability includes understanding the maintenance of forest cover (extent and carbon dynamics), the shift from initial occupation to consolidation of land use in large colonization areas, and the rate of changes [e.g., migration, lot turn-over] in areas designated for agrarian reform.

2. Developing an integrated study of land use, land cover, and land-water interactions by linking our detailed studies of soil, plant, and stream biogeochemistry in forested sites across the Basin, with the larger datasets from LBA and global datasets that address the fundamental questions of the landscape-level controls on nutrient-carbon interactions within, and sustainability of, forests in the Amazon. This should allow us to address sustainability of forests by connecting our trajectories of change at our study sites to the larger regions within which they exist.

3. Developing a synthesis of Human Dimensions research for LBA and an approach to scientific collaboration between the partner institutions in Brazil and the US that will result in continuing and expanding a comprehensive program of education and training including courses, workshops, and Ph.D. training successfully started and developed during LBA Phases I and II.

Description Building on 25 years of research experience in the Eastern Amazon, this study advances our understanding of land use and land cover change. It is developing a Spectral Library that will serve the research community and assist in testing of a new generation of sensors (e.g. TM7). This project builds on a seven-region study, along the LBA transects, supported for the past six years by NSF and NIGEC, and encompassing a sample of 100+ sites. We use a nested-georeferenced approach that included soil analysis, vegetation stand structure and composition, land use histories, institutional analyses, demography of households, and land cover classification using Landsat TM multitemporal data to understand the rates of growth of secondary vegetation. The seven regions' study provides a wide array of land uses and land cover along an east-to-west transect extending from the Amazon estuary and Bragantina region east of Belém near the Atlantic coast, all the way to the Tapajos/Santarem region with a Rondnia site now also being added. This 160,000 km2 area will be examined for land cover changes and their relation to past patterns of land use for a minimum of no less than 25 years. We propose in this NASA/LBA project to extend this work by:
A. Combining field inventories of soil and vegetation to quantify ecological thresholds driving structural and functional dynamics (e.g. rates of regrowth and species replacement) of secondary succession areas subjected to different land use histories across the seven study regions;
B. Developing measures of landscape structure and spatial and temporal dynamics of different land use scenarios, resulting in models of socioeconomic, institutional, and demographic determinants of land use and cover change;
C. Developing a spectral library of land cover classes present that can be applied to previous (MSS and TM5) and forthcoming sensors (TM7) through the integration of the cited vegetation inventories, image calibration, and hyperspectral field assessment;
D. Ensuring robust contribution to LBA, we will take this opportunity to synthesize, model, and share data by linking ACT's and INPE's data sets and experience to other primary and secondary data sets along LBA's east-west transect and to the work in Rondônia of colleagues at INPE and with Virginia Dale, et al. at the Oak Ridge National Laboratory (ORNL). We foresee close collaboration with them on modeling land use and land cover, spatial analysis metrics, environmental analysis, and a participatory model; and
E. Providing hands-on experience to a cohort of Brazilian students in their work on land use/cover change and the human dimensions of such change in research in the Amazon region leading to doctoral degrees, and to provide other opportunities for mid-career training preferentially to colleagues at Amazônian institutions.
This study will provide a suite of site-specific, multitemporal satellite and field data and analyses of land use and land cover change dynamics within the comparative framework proposed by LBA. Hyperspectral calibration of a range of land covers of interest to LBA, such as mature upland and floodplain forests, stages of secondary successional vegetation, selectively logged forests, pastures, annual and perennial cropped fields, and savannas, will be an important component of this study. We will develop a detailed understanding of both spatial and temporal scaling from household/farm area to regional scale.
Building on 30 years of research experience in the Amazon, this study will advance our understanding of land use and land cover change through integrative science activities and by collaboration with 11 other LBA projects. This project builds on a seven-region study, along the LBA transects, supported for six years by NSF and NIGEC, and then for the past three years by LBA funds. We have used a nested-georeferenced approach that collected soil analyses, vegetation stand structure and composition (100+ sites), land use histories, institutional analyses, demography of 600+ households, and land cover classification using Landsat MSS and TM multitemporal data to understand land use and land cover change (LCLUC) trajectories. The seven regions in our study represent a soil fertility gradient across Amazônia from most (i.e. alfisols) to least (i.e. spodosols) fertile and include a wide array of land uses and land cover types along an east-to-west transect extending from the Amazon estuary and Bragantina region east of Belém, all the way to Rondônia in the west.
We propose in Phase II of this NASA/LBA project to extend this work by:
1. Developing a multi-scale synthesis of land use and land cover change dynamics integrating our seven study areas, in order to understand the role of demographic, economic, institutional and biophysical variables on LCLUC trajectories during the past 25 years.
2. Developing a multi-sensor analysis of the capabilities and limitations of different platforms (IKONOS-TM & ETM+-MODIS) for land cover discrimination using the full capabilities of artificial neural networks for classification and modeling.
3. Developing an integrated study of land use, land cover, and land-water interactions by using a watershed approach, encompassing at least two of our most intensive research sites (i.e. the Santarém-Altamira region), thereby addressing fundamental questions of the landscape-level controls on nutrient-carbon interactions within, and sustainability of forests in the Amazon Basin.
4. Developing a comprehensive scientific collaboration strategy to contribute to modeling and synthesis efforts by formal collaboration with 11 LBA projects, hands-on training, and dissemination of a data management CD for the benefit of all of LBA.
Click here to request access to ACT LBA data

Description The initial phase of this project focused on the initial demographic composition of the households of smallholder settlers entering the agricultural frontier, how those demographic characteristics changed over time, and how these changes interacted with other characteristics of households to determine patterns of forest clearing and regrowth. This initial phase involved collecting social survey data from landowning households on 402 properties in one study area in a colonization area to the west of the city of Altamira (including parts of the current municípios of Altamira, Brasil Novo, Medicilândia, and Uruará) in 1997 and 1998. These data were linked to satellite data, classified into areas with various land uses, by using property boundaries. This project was, to our knowledge, the first to make the social survey . satellite data linkage through the use of cadastral maps updated with field data, a practice that is now relatively common among population and environment researchers (e.g. Walsh et al. 2005, Fox et al. 2003), and that developed methods that permitted querying and analysis at the level of the individual property as well as the landscape (Moran and Brondizio 1998).

This early work drew on a conceptual model of the developmental cycle of domestic groups that indicated that deforestation patterns would change in a predictable way over the lives of households as their available labor and consumption needs changed. Young households have little available labor and relatively high consumption needs. Over time, labor increases and consumption needs stabilize. We argued that this resulted in a distinctive pattern of land use change over time. Surprisingly, we found that it is upon arriving in the frontier, when most frontier households are youngest, that one finds the highest rates of deforestation (Brondizio et al. 2002). Surprising, too, is the finding that within five years, most households are on a trajectory of declining rates of deforestation that persists over the next 10 year period (McCracken et al. 2002). There is a short-term increase in deforestation associated with consolidation of the areas farmed (approximately 15 years after settlement), followed by a steady decline in deforestation rates. Each cohort appears to follow this trajectory no matter at what time they arrived, even if they came during a period of hyperinflation and tight credit policy (Brondizio et al. 2002). While the magnitude of an individual household.s deforestation is a product of period effects, increasing when credit rates are lower and inflation is lower, the trajectory of deforestation is the same across arrival cohorts. In fact, our analysis showed that aggregate deforestation rates declined during the 1980.s because the much larger population representing earlier arriving cohorts had entered into a period of declining rates of deforestation, compounded with the unfavorable conditions for farm expansion (Moran and Brondizio 2001).

Our conceptual model initially suggested a shift from pasture to perennial crops as a time- and capital-dependent shift in land use strategy associated with the aging of household members. However, our analyses showed that the decision between perennials and pasture is explained better by differences in the physical endowments of the farm (Moran et al. 2002; Moran et al. 2000). We found a linear relationship between the proportion of high quality soils on the farm and the proportion of the property in pasture. Whereas properties that are characterized by acid, low nutrient soils have over 80% of their deforested area in pasture, this percentage drops in proportion to the amount of good soils on the property until it reaches a balanced amount of pasture and perennial crops (mostly cocoa and sugar cane) on properties with mostly good soils (i.e. terra roxa estruturada eutrófica or alfisols). This suggests a learning process where farmers learn over time the differences that soils make in yield, and those with good soils develop balanced portfolios of land use, whereas those with poor soils tend to focus only on pasture and are unable to evolve their strategy in the direction of perennial crops.

Based on these main findings of the initial phase of the project, our second phase proposed a further test of the conceptual model and exploration of the mechanisms underlying it (migration and marriage as components of changing household labor availability, off-farm employment, as well as biophysical constraints on household decisions). We expanded the geographic extent of our project by adding a study area in the agricultural area to the south of the city of Santarém (including parts of the current municípios of Santarém and Belterra). The Altamira study area settlement scheme began only in 1971 and thus we were able to capture only the actions of first generation settlers. In the second phase of the project, we examined a much older Amazon region where we were able to examine trajectories of land use change among later generations of settlers, and collected a second wave of data in Altamira. We collected new social survey data on households and farms in Santarém in 2003, including in this data collection all households (owners and residents) on sampled rural properties. We used a multistage cluster sampling approach: within each of four regions in the study area (each with a different settlement history), we selected a random sample of grid cells (each being nine square kilometers); we then selected a random sample of properties from existing cadastral maps within each grid cell; we then interviewed every household in each selected property. This spatial sample and the interviewing of all households in each property produced a sample that allows results of models including specific subsamples of the data to be generalized to the population of households as well as to the populations of properties or landowning households. The follow up data in Altamira provided a prospective look at changes in households and properties between 1997/98 and 2005. We followed properties, owning households, and children who had been living in the owning households in 1997/98. Thus, this phase of the project allows us to more persuasively examine the reciprocal relationships between population and environment.

The data collected in Santarém allowed us to conduct comparative analyses of the effects of household life cycle stage on land use and land cover in Altamira and Santarém. The first of these comparative analyses examines the independent effects of household life cycle (or household age) and of time since acquisition of the property on land use (VanWey et al. in revision). Our past work on the cycles of deforestation used the time of settlement as a proxy for the start of the household life cycle, based on the observation that most settlers were young families (McCracken et al. 1999). However, there is considerable variation in the time between and sequence of formation of a household (marriage) and acquisition of a property. Our results show that what we had previously seen in an examination of trajectories of deforestation based on satellite data overlaid with property boundaries was actually a cycle of deforestation following a standard pattern over the time since acquisition of a property by a household. These results, showing a .property life cycle,. are consistent with patterns shown by Pan and Bilsborrow (2005) in the Ecuadorian Amazon and Perz et al. (in press) in Uruará. There is no independent effect of head of household age once the time since acquisition of the property is controlled. Our recent analyses further show that this property life cycle is only evident in Altamira, arguably because Altamira is a new frontier and settlers are arriving on largely forested properties about which they know relatively little. In contrast, in Santarém, we find no effect of household age or time since acquisition, finding instead evidence of property level production specialization. The initial land use on a property at the time of acquisition has a lasting effect, suggesting that households select land with a given use in mind in this region where generations of settlers have learned the most appropriate uses of properties given biophysical characteristics and proximity to markets.

The second set of comparative analyses examines the mechanisms put forward in our and others. development of the household life cycle model (Brondizio et al. 2002; McCracken et al. 1999; Perz et al. in press; Perz and Walker 2002; Walker 2003). We explicitly test the effects of changing household demographic composition on changes in forest area and used area (measured using both survey data and satellite data) using fixed effects regression models (VanWey, et al. under review). We find no support for the argument that production depends on available household labor (in this context, male adolescents and adults). Models show instead that changes in the number of children and women, particularly young women, have the most significant effects on land use and land cover change. We speculate that this is in part due to government subsidies for education and in part reflects endogenously determined migration decisions of young women. These two sets of comparative analyses indicated that households, in fact, are engaged in production for local and regional economies with expansion in mind rather than production primarily for household consumption (as assumed in Chayanov 1966; Perz et al. in press; Perz and Walker 2002; Walker 2003).

In addition to these questions about the relationship between household life cycle and land use / land cover, our second phase of the project addressed directly some of the family processes underlying changes in households and residents of properties over time. In the first phase of this project, we found a rapid decline in fertility across birth cohorts in the frontier, which arguably should be characterized by high fertility given land abundance and labor scarcity. We found that women use a variety of methods of fertility control and reduction with more than 80% having used some form of fertility control in the past (Siqueira and McCracken 2001) and the two youngest cohorts of reproductive age women being aware of their contraceptive options (Siqueira et al. under review). Most notable among these is the widespread use of sterilization, usually after having two children. We found that over 43% of women in the Altamira study area were sterilized by age 25-29.and that this procedure was tied closely (i.e. in 70% of cases) to cesarean birth events. To follow up on this finding, we specifically examined sterilization in our Santarém study area (after verifying the same fertility decline among the population). Our work on sterilization in Santarém confirms the prevalence of sterilization, and offers a contrast to findings from the Northeast of Brazil where it is tied to political clientilism (Caetano and Potter 2004). In our study area the use of sterilization is a strategy pursued by women and financed by their own resources (Siqueira et al. under review). Reversible contraceptive methods are difficult and costly to access outside of the urban area of Santarém, and those women who have used hormonal methods (overwhelmingly the pill in this area) in the past report high rates of adverse health effects due to the high hormonal content of the available pills and lack of medical follow up.

We additionally have examined the determinants of inter-generational co-residence on farm properties, focusing on the differences between daughters and sons in the determinants of co-residence (VanWey and Cebulko, in revision). In our earlier work in Altamira, we found that daughters were substantially more likely to leave their parents. farm, and that they were more likely to be moving to the city (McCracken and Siqueira 2000). We verified this result in Santarém and further found that there are no significant differences in the effects of children.s or parents. characteristics on living out of the parents. household versus living off of the parents. property. Congruent with fieldwork observations, living together on a property is virtually equivalent to sharing a household. We also found that not only were daughters more likely to live off the farm, it was the daughters with the most education and from wealthier backgrounds (farm-owning rather than farm workers) who were the most likely to live away from their parents. Finally, our second phase of the project involved analyses of the importance of the entry of large farmers, associated land consolidation, and urbanization in the Santarém region. Though these issues were not specific aims of our phase II proposal, they were immediately evident in the field. In 2003, we arrived in Santarém months after the opening of a deep water port operated by the multinational Cargill to facilitate the export of soybeans from the Center of Brazil (the Mato Grosso region). This port (and the anticipation of it) spurred the growth of soybean production in the region and the arrival of large capital to transform the landscape from one of small farms to one of large mechanized farms in a favorably flat plateau. When we went to the field with our sample drawn from cadastral maps, we found that fully half of the sampled properties were no longer small farms, with most now part of large mechanized farms. In an analysis of the locations of these large farms and other forms of property consolidation, we found that while there were high rates of consolidation close to the better roads to Santarém, there were also high rates of consolidation in forested regions far from good roads and far from the city (VanWey, et al. manuscript).

We further explore the impacts of land consolidation only among small farmers by examining the impact of property size on forest cover and forest cover change (D.Antona, VanWey and Hayashi, in press). We find that larger properties are able to preserve a larger proportion of their area in forest, and also are able to allow previously used area to go through longer fallow cycles, with vegetation growing for long enough to be indistinguishable from forest in satellite imagery. In this new phase of the project, we will further explore this process of consolidation and mechanization in order to assess its long-term impacts on forest cover among other things.

In considering urbanization, we have also drawn on field experiences. Using our experiences in several sampled properties which at the time of the survey had an unexpected combination of agricultural lands and residential parcels, we developed a typology of property trajectories. These show that some properties in the rural zones around Santarém are in fact increasing in both housing density and infrastructure, a sort of rural urbanization (D.Antona and VanWey, under review). Associated sometimes with processes of inheritance and sometimes with explicit household strategies, properties are being subdivided below the threshold for viable agricultural use. In some cases, households are self-financing some infrastructure (bars, churches) in an effort to leverage public investment in infrastructure (electrification, piped water, schools, health centers).

The two phases of the project to date have also made useful technical and methodological contributions. Of particular note in the first phase of the project is our development of an approach that permits querying at both a landscape and household/property level (McCracken et al. 1999; McCracken et al. 2003; Brondizio et al. 2002; Moran et al. 2002; McCracken et al. 2003). This technical approach represented a breakthrough in the analysis of population and environment. Previous work, for an area this size (3800 sq km), had typically analyzed and described land-cover change from the perspective of the landscape, without addressing the differential and multiple land use dynamics at the level of individual farms and households, or had analyzed land use from aspatial survey data. This dynamic querying at both property and landscape levels has proven productive, as it helps identify different patterns on the landscape and relate the behavior of households to their economic, demographic, and biophysical characteristics in a spatially explicit fashion.

In the second phase of the project, we focused on improving sampling methods to allow us to examine the reciprocal relations between population and environment. As described above, we designed a multi-stage cluster sampling approach in Santarém that allows results from the full sample or various subsamples to be generalized to the population of households or to the population of properties (the landscape). In our first phase of data collection in Altamira, we took advantage of properties usually containing only one household to collect data simultaneously at the household and property level, making that initial sample also generalizable to both the population of households and the landscape. In 2005, we conducted a three-pronged follow up in Altamira: (1) we re-interviewed the previously interviewed owner (and spouse); (2) we conducted interviews with owners and all resident households on previously interviewed properties; and (3) we interviewed children of the initial owner who had been living in the owners. household in the first wave. To our knowledge, we are the first team to conduct a simultaneous follow up of both households and properties, allowing us to look longitudinally at both environmental effects on population change and population effects on environmental change.

Description: This project undertook an analysis of human coping strategies to ENSO-related drought, in light of the growing flammability of forests in two regions of the Brazilian Amazon. Recent studies suggest that 60% or more of areas currently experiencing burning in the Brazilian Amazon burn unintentionally. In the past, tropical moist forests were sufficiently resistant to fire disturbance because closed canopies maintained high moisture levels in the understory, suppressing fire penetration at ground level. Fragmentation of forests, selective logging, and other anthropogenic driving forces have opened the canopy and created warmer and drier conditions at ground level that are more conducive to the spread of fire. This drying of forests is exacerbated during ENSO events. In the El Niño of 1997-98, researchers estimate that over half of forests burnt in the Brazilian Amazon during that time were a product of the unintentional spread of fire due to extremely dry conditions. Research on the extent of biomass burning and cumulative trace gas emissions in Amazônia has paid insufficient attention to the growing proportion of unintentional fires and the human dimensions of this growing vulnerability. Human vulnerability to climate varies among social groups, depending on property size, land use and technology used, and their access to forecasting information. It is not widely recognized that Amazonian forests can catch fire. This misperception on the part of scientists, policy makers, and forecasters may be implicated in the way information is communicated to end-users. Our goal was to reconstruct the timing, content and dissemination of forecasts for the 1997-98 ENSO, trace household responses, and evaluate land-cover change in order to improve dissemination and future use of forecasts, reduce socioeconomic losses due to drought, and minimize spread of fire into forests.

To accomplish these objectives, a combination of social and environmental field research methods and analysis of remotely-sensed data were used. Field methods included archival and survey research to reconstruct the history of land use and determine: 1) people=s assessment of changing local fire spread and its relation to ENSO forecasts, 2) people=s trust in the forecasts by source, 3) how the use of the forecasts was affected by fiscal policy and by the growing health risks from the heavy smoke from fires, 4) the changing economic value of forest in each area, and 5) to measure the extent of unintentional fire spread. Interviews with policy and decision makers assessed their awareness of ENSO forecasts, and their understanding of their relevance for the study areas. Remotely-sensed data was used to track changes in land cover, and changing land use as influenced by forecasts and changing moisture levels. The study also examined the growth of cities in these two regions, and what role urbanization may play in exacerbating or ameliorating this situation.

We selected a medium-sized city, Santarém (population~260,000) and a small city, Altamira (population~85,000) and their rural periphery. The number of medium and small Amazonian cities has grown rapidly and they have notable importance in land-use and land-cover change because of growing rural-to-urban migration, and the growing proportion of urbanites= wealth in rural real estate. The process of assessment by individuals and groups as they organize to bring about reduced vulnerability to the consequences of ENSO events and to the spread of fire was of particular interest in this study. The last ENSO was accurately forecast, 85% of the population in the study areas regularly view television news programs that include information about ENSO, and yet, little is known of the coping strategies of this past forecast in order to understand how best to prepare the population for future ones, and reduce their growing vulnerability from fires. How results have furthered the field of understanding and analyzing the use of climate information in decision-making :

This is the first study to examine how ENSO affects rural and urban populations in the Amazon, and the coping strategies of the population to the 1997-98 ENSO, and we plan to see the responses also to the currently forecast ENSO. In Brazil it does not appear that the climate community felt that it was worthwhile calling this an ENSO event. However, in October some farmers were describing this ENSO as almost as severe in the early stages as the one in 1997-98.

One of the challenges of global change research is to make scientific information more relevant to decision makers at the local and regional level. This study has already begun to engage local actors (NGOs, government agencies, TV and other local media, information Abrokers@, and individual land users) in the process of evaluating the use of climate forecasts. All those interviewed expressed surprise when they discovered that the Aother@ agency also had not transmitted a local forecast. It seems each media source assumed another media was doing so! The 1997-98 ENSO is the focus of attention, but other forecasts are being used in assessing the use of information. In addition, experiments in focus groups will be conducted with the above local informants to see how severity, magnitude, and other characteristics of the forecast influence their propensity to make different decisions about the use of fire, the use of land, and other economically relevant strategies (e.g. sell cattle, not harvest crops). The impact of drought is mediated by access to adaptive technologies, crop prices, subsidies and insurance. Access to these adaptations is highly variable by region, sector, and social group. Smallholders, for example, have been noted to lack the financial and technological means to make firebreaks, but some of them do--Why? ENSO can be forecast with three to twelve-month advance notice, and the potential impacts of ENSO on agriculture, health, water resources, and fire can be evaluated before, during and after the event. Since the Altamira-Santarém region is considered a particularly important agropastoral production zone, a goal of the study is to evaluate how well decision makers use available information and adaptive technologies to reduce vulnerability of people in the region. Does the size of the city influence the flow of information or trust in it? Are the dominant crops particularly vulnerable to precipitation shortfalls (pasture vs. tree crops)? Does one region have a more effective method of delivering climate forecast information than the other? Are special fiscal instruments made available in a timely fashion to reduce risks to all, or only some, stakeholders?

A. Where appropriate, describe how this research builds on any previously funded HDGEC research: This research builds on earlier work funded by NSF and NASA. These other studies permitted accumulation of very detailed data on vegetation, soils, and land cover classes. The current work under NOAA allows us to address the coping strategies of farmers and their responses to the possibilities of widespread fire risk as a result of drought associated with ENSO. Without this support, we would not have addressed these fire-related questions.
This research was partly built from previous studies on the impact of fire use on biomass burning in the agricultural frontier of Santarém, Pará, which was funded through a NASA Earth Systems Science Fellowship which is a part of their HDGEC programs.

B. Suggestions for Future Research Future research will need to focus more on increasing the network of micromet stations and ensuring that these data are reported and used in forecasts. Currently, the data is archived more than used and there is very little effort to make data available to users or even researchers. Efforts by NOAA, together with their Brazilian CPTEC equivalents, to have an open-access policy on precipitation data in close to real time would be a huge step forward.

Description: The initial phase of this project focused on the initial demographic composition of the households of smallholder settlers entering the agricultural frontier, how those demographic characteristics changed over time, and how these changes interacted with other characteristics of households to determine patterns of forest clearing and regrowth. This initial phase involved collecting social survey data from landowning households on 402 properties in one study area in a colonization area to the west of the city of Altamira (including parts of the current municípios of Altamira, Brasil Novo, Medicilândia, and Uruará) in 1997 and 1998. These data were linked to satellite data, classified into areas with various land uses, by using property boundaries. This project was, to our knowledge, the first to make the social survey . satellite data linkage through the use of cadastral maps updated with field data, a practice that is now relatively common among population and environment researchers (e.g. Walsh et al. 2005, Fox et al. 2003), and that developed methods that permitted querying and analysis at the level of the individual property as well as the landscape (Moran and Brondizio 1998).

This early work drew on a conceptual model of the developmental cycle of domestic groups that indicated that deforestation patterns would change in a predictable way over the lives of households as their available labor and consumption needs changed. Young households have little available labor and relatively high consumption needs. Over time, labor increases and consumption needs stabilize. We argued that this resulted in a distinctive pattern of land use change over time. Surprisingly, we found that it is upon arriving in the frontier, when most frontier households are youngest, that one finds the highest rates of deforestation (Brondizio et al. 2002). Surprising, too, is the finding that within five years, most households are on a trajectory of declining rates of deforestation that persists over the next 10 year period (McCracken et al. 2002). There is a short-term increase in deforestation associated with consolidation of the areas farmed (approximately 15 years after settlement), followed by a steady decline in deforestation rates. Each cohort appears to follow this trajectory no matter at what time they arrived, even if they came during a period of hyperinflation and tight credit policy (Brondizio et al. 2002). While the magnitude of an individual household.s deforestation is a product of period effects, increasing when credit rates are lower and inflation is lower, the trajectory of deforestation is the same across arrival cohorts. In fact, our analysis showed that aggregate deforestation rates declined during the 1980.s because the much larger population representing earlier arriving cohorts had entered into a period of declining rates of deforestation, compounded with the unfavorable conditions for farm expansion (Moran and Brondizio 2001).

Our conceptual model initially suggested a shift from pasture to perennial crops as a time- and capital-dependent shift in land use strategy associated with the aging of household members. However, our analyses showed that the decision between perennials and pasture is explained better by differences in the physical endowments of the farm (Moran et al. 2002; Moran et al. 2000). We found a linear relationship between the proportion of high quality soils on the farm and the proportion of the property in pasture. Whereas properties that are characterized by acid, low nutrient soils have over 80% of their deforested area in pasture, this percentage drops in proportion to the amount of good soils on the property until it reaches a balanced amount of pasture and perennial crops (mostly cocoa and sugar cane) on properties with mostly good soils (i.e. terra roxa estruturada eutrófica or alfisols). This suggests a learning process where farmers learn over time the differences that soils make in yield, and those with good soils develop balanced portfolios of land use, whereas those with poor soils tend to focus only on pasture and are unable to evolve their strategy in the direction of perennial crops.

Based on these main findings of the initial phase of the project, our second phase proposed a further test of the conceptual model and exploration of the mechanisms underlying it (migration and marriage as components of changing household labor availability, off-farm employment, as well as biophysical constraints on household decisions). We expanded the geographic extent of our project by adding a study area in the agricultural area to the south of the city of Santarém (including parts of the current municípios of Santarém and Belterra). The Altamira study area settlement scheme began only in 1971 and thus we were able to capture only the actions of first generation settlers. In the second phase of the project, we examined a much older Amazon region where we were able to examine trajectories of land use change among later generations of settlers, and collected a second wave of data in Altamira. We collected new social survey data on households and farms in Santarém in 2003, including in this data collection all households (owners and residents) on sampled rural properties. We used a multistage cluster sampling approach: within each of four regions in the study area (each with a different settlement history), we selected a random sample of grid cells (each being nine square kilometers); we then selected a random sample of properties from existing cadastral maps within each grid cell; we then interviewed every household in each selected property. This spatial sample and the interviewing of all households in each property produced a sample that allows results of models including specific subsamples of the data to be generalized to the population of households as well as to the populations of properties or landowning households. The follow up data in Altamira provided a prospective look at changes in households and properties between 1997/98 and 2005. We followed properties, owning households, and children who had been living in the owning households in 1997/98. Thus, this phase of the project allows us to more persuasively examine the reciprocal relationships between population and environment.

The data collected in Santarém allowed us to conduct comparative analyses of the effects of household life cycle stage on land use and land cover in Altamira and Santarém. The first of these comparative analyses examines the independent effects of household life cycle (or household age) and of time since acquisition of the property on land use (VanWey et al. in revision). Our past work on the cycles of deforestation used the time of settlement as a proxy for the start of the household life cycle, based on the observation that most settlers were young families (McCracken et al. 1999). However, there is considerable variation in the time between and sequence of formation of a household (marriage) and acquisition of a property. Our results show that what we had previously seen in an examination of trajectories of deforestation based on satellite data overlaid with property boundaries was actually a cycle of deforestation following a standard pattern over the time since acquisition of a property by a household. These results, showing a .property life cycle,. are consistent with patterns shown by Pan and Bilsborrow (2005) in the Ecuadorian Amazon and Perz et al. (in press) in Uruará. There is no independent effect of head of household age once the time since acquisition of the property is controlled. Our recent analyses further show that this property life cycle is only evident in Altamira, arguably because Altamira is a new frontier and settlers are arriving on largely forested properties about which they know relatively little. In contrast, in Santarém, we find no effect of household age or time since acquisition, finding instead evidence of property level production specialization. The initial land use on a property at the time of acquisition has a lasting effect, suggesting that households select land with a given use in mind in this region where generations of settlers have learned the most appropriate uses of properties given biophysical characteristics and proximity to markets.

The second set of comparative analyses examines the mechanisms put forward in our and others. development of the household life cycle model (Brondizio et al. 2002; McCracken et al. 1999; Perz et al. in press; Perz and Walker 2002; Walker 2003). We explicitly test the effects of changing household demographic composition on changes in forest area and used area (measured using both survey data and satellite data) using fixed effects regression models (VanWey, et al. under review). We find no support for the argument that production depends on available household labor (in this context, male adolescents and adults). Models show instead that changes in the number of children and women, particularly young women, have the most significant effects on land use and land cover change. We speculate that this is in part due to government subsidies for education and in part reflects endogenously determined migration decisions of young women. These two sets of comparative analyses indicated that households, in fact, are engaged in production for local and regional economies with expansion in mind rather than production primarily for household consumption (as assumed in Chayanov 1966; Perz et al. in press; Perz and Walker 2002; Walker 2003).

In addition to these questions about the relationship between household life cycle and land use / land cover, our second phase of the project addressed directly some of the family processes underlying changes in households and residents of properties over time. In the first phase of this project, we found a rapid decline in fertility across birth cohorts in the frontier, which arguably should be characterized by high fertility given land abundance and labor scarcity. We found that women use a variety of methods of fertility control and reduction with more than 80% having used some form of fertility control in the past (Siqueira and McCracken 2001) and the two youngest cohorts of reproductive age women being aware of their contraceptive options (Siqueira et al. under review). Most notable among these is the widespread use of sterilization, usually after having two children. We found that over 43% of women in the Altamira study area were sterilized by age 25-29.and that this procedure was tied closely (i.e. in 70% of cases) to cesarean birth events. To follow up on this finding, we specifically examined sterilization in our Santarém study area (after verifying the same fertility decline among the population). Our work on sterilization in Santarém confirms the prevalence of sterilization, and offers a contrast to findings from the Northeast of Brazil where it is tied to political clientilism (Caetano and Potter 2004). In our study area the use of sterilization is a strategy pursued by women and financed by their own resources (Siqueira et al. under review). Reversible contraceptive methods are difficult and costly to access outside of the urban area of Santarém, and those women who have used hormonal methods (overwhelmingly the pill in this area) in the past report high rates of adverse health effects due to the high hormonal content of the available pills and lack of medical follow up.

We additionally have examined the determinants of inter-generational co-residence on farm properties, focusing on the differences between daughters and sons in the determinants of co-residence (VanWey and Cebulko, in revision). In our earlier work in Altamira, we found that daughters were substantially more likely to leave their parents. farm, and that they were more likely to be moving to the city (McCracken and Siqueira 2000). We verified this result in Santarém and further found that there are no significant differences in the effects of children.s or parents. characteristics on living out of the parents. household versus living off of the parents. property. Congruent with fieldwork observations, living together on a property is virtually equivalent to sharing a household. We also found that not only were daughters more likely to live off the farm, it was the daughters with the most education and from wealthier backgrounds (farm-owning rather than farm workers) who were the most likely to live away from their parents. Finally, our second phase of the project involved analyses of the importance of the entry of large farmers, associated land consolidation, and urbanization in the Santarém region. Though these issues were not specific aims of our phase II proposal, they were immediately evident in the field. In 2003, we arrived in Santarém months after the opening of a deep water port operated by the multinational Cargill to facilitate the export of soybeans from the Center of Brazil (the Mato Grosso region). This port (and the anticipation of it) spurred the growth of soybean production in the region and the arrival of large capital to transform the landscape from one of small farms to one of large mechanized farms in a favorably flat plateau. When we went to the field with our sample drawn from cadastral maps, we found that fully half of the sampled properties were no longer small farms, with most now part of large mechanized farms. In an analysis of the locations of these large farms and other forms of property consolidation, we found that while there were high rates of consolidation close to the better roads to Santarém, there were also high rates of consolidation in forested regions far from good roads and far from the city (VanWey, et al. manuscript).

We further explore the impacts of land consolidation only among small farmers by examining the impact of property size on forest cover and forest cover change (D.Antona, VanWey and Hayashi, in press). We find that larger properties are able to preserve a larger proportion of their area in forest, and also are able to allow previously used area to go through longer fallow cycles, with vegetation growing for long enough to be indistinguishable from forest in satellite imagery. In this new phase of the project, we will further explore this process of consolidation and mechanization in order to assess its long-term impacts on forest cover among other things.

In considering urbanization, we have also drawn on field experiences. Using our experiences in several sampled properties which at the time of the survey had an unexpected combination of agricultural lands and residential parcels, we developed a typology of property trajectories. These show that some properties in the rural zones around Santarém are in fact increasing in both housing density and infrastructure, a sort of rural urbanization (D.Antona and VanWey, under review). Associated sometimes with processes of inheritance and sometimes with explicit household strategies, properties are being subdivided below the threshold for viable agricultural use. In some cases, households are self-financing some infrastructure (bars, churches) in an effort to leverage public investment in infrastructure (electrification, piped water, schools, health centers).

The two phases of the project to date have also made useful technical and methodological contributions. Of particular note in the first phase of the project is our development of an approach that permits querying at both a landscape and household/property level (McCracken et al. 1999; McCracken et al. 2003; Brondizio et al. 2002; Moran et al. 2002; McCracken et al. 2003). This technical approach represented a breakthrough in the analysis of population and environment. Previous work, for an area this size (3800 sq km), had typically analyzed and described land-cover change from the perspective of the landscape, without addressing the differential and multiple land use dynamics at the level of individual farms and households, or had analyzed land use from aspatial survey data. This dynamic querying at both property and landscape levels has proven productive, as it helps identify different patterns on the landscape and relate the behavior of households to their economic, demographic, and biophysical characteristics in a spatially explicit fashion.

In the second phase of the project, we focused on improving sampling methods to allow us to examine the reciprocal relations between population and environment. As described above, we designed a multi-stage cluster sampling approach in Santarém that allows results from the full sample or various subsamples to be generalized to the population of households or to the population of properties (the landscape). In our first phase of data collection in Altamira, we took advantage of properties usually containing only one household to collect data simultaneously at the household and property level, making that initial sample also generalizable to both the population of households and the landscape. In 2005, we conducted a three-pronged follow up in Altamira: (1) we re-interviewed the previously interviewed owner (and spouse); (2) we conducted interviews with owners and all resident households on previously interviewed properties; and (3) we interviewed children of the initial owner who had been living in the owners. household in the first wave. To our knowledge, we are the first team to conduct a simultaneous follow up of both households and properties, allowing us to look longitudinally at both environmental effects on population change and population effects on environmental change.

Description: This project has contributed to increasing Latin American capacity in environmental analysis and environmental monitoring using a two-pronged approach: on the one hand, by enhancing access by a group of Mexican and Brazilian scholars and active environmentalists to the latest techniques of environmental monitoring; and on the other, by linking the application of these tools to policy interventions that may enhance environmental protection of species-rich tropical moist forests in the Brazilian Amazon and Southeastern Mexico. By strengthening capacity and reducing dependency on environmentalists from the U.S. and Europe, the environmental future of Latin America is more likely to be preserved by those with the greatest stake in it. During the first two years the project activities included in-house training of a select number of researchers and environmental protection agency personnel, and intensive training sessions in Brazil and Mexico respectively. In the third year an international symposium was conducted, and a volume will be published that will extend the value of the environmental analysis and policy training activities to other countries of Latin America. The volume will be made available in English, Spanish and Portugal.

Description: Concern with the alarming rates of deforestation in the Amazon Basin has unwittingly led to overlooking the possible role of successional processes in tropical moist and rain forests. As much as 85% of areas cleared are recolonized by native tree species within a few years after clearing. Examination of these processes, as well as how local populations manage land in order to accelerate or retard succession, offers an opportunity to understand how such regions may be managed in the future, how carbon emissions at regional level may be stabilized, how climate and biodiversity are affected by differential successional rates, and how conservation and restoration projects may be implemented.
This project undertook a comparative analysis of deforestation and ecological succession in the Brazilian Amazon and the role of these processes in the global carbon cycle. Two oligotrophic sites were studied in the Zona Bragantina and one in the Rio Negro Basin. These three sites were contrasted to two eutrophic sites (one in the Lower Xingu basin and the other at Marajo island) studied for the past two years with support from NSF. At each field site, the following data were collected: (1) history of land use, (2) forest stand structure (i.e. composition, relative abundance and spatial dispersion of trees) (3) carbon content and nutrient characterization of plants and soils, and (4) climatological data to assess changes in temperature, precipitation, albedo and evaporation at sites with contrasting areal extent of deforestation. These field data were integrated with remotely-sensed imagery of these regions. An important component in this analysis was the use of multitemporal Landsat Thematic Mapper digital data to provide a regional-scale capability for assessing successional dynamics jointly with radar digital data to enhance the terrain analysis and GOES data to estimate volume and areal distribution of rainfall. A carbon balance model were developed using field data and geo-referenced to specific sites using GIS.
Current estimates tend to overlook the variability in rates of regrowth, and thus in differential carbon release and uptake in tropical moist and rain forests. We have found differences of up to a factor of seven in rates of regrowth as a function of differences in soil fertility, land use, and size of area cleared in the eutrophic areas studied. The procedures outlined here have proven feasible for the past two years' work in two eutrophic sites. It is necessary to extend the understanding gained at the eutrophic sites to the more common nutrient-poor regions of Amazonia if we are to understand the Amazon's contribution to global warming. To ensure the relevance of this study to issues of global warming and carbon cycling, the proposed project will have the collaboration of two climatologists, a plant ecologist, and a senior remote sensing specialist. During the 1992 field study, it came to our attention that a decline of 100 mm had taken place in the most deforested region studied, and that the number of rainless days had increased over the past 20 years. Given that both eutrophic and oligotrophic sites under study are largely in the eastern Amazon, this provides a unique opportunity to examine the possible role of changes in rainfall regime on the vegetation, on species diversity (with potential high mortality of endemics with narrow ranges of adaptability to drier conditions), and on land cover.

Description: This project is undertaking a comparative analysis of deforestation and ecological succession in the Brazilian Amazon and the role of these processes in the global carbon cycle. Two oligotrophic sites are studied in the Eastern Amazon. These three sites are contrasted to two eutrophic sites (one in the Lower Xingu basin and the other at Marajo island) studied between 1991 and 1993 with support from NSF. At each field site, the following data will be collected: (1) history of land use, (2) forest stand structure (i.e. composition, relative abundance and spatial dispersion of trees) (3) carbon content and nutrient characterization of plants and soils, and (4) climatological data to assess changes in temperature, precipitation, albedo and evaporation at sites with contrasting areal extent of deforestation. These field data will be integrated with remotely-sensed imagery of these regions. An important component in this analysis is the use of multitemporal Landsat Thematic Mapper digital data to provide a regional-scale capability for assessing successional dynamics. A carbon balance model will be developed using field data and geo-referenced to specific sites using GIS. It is necessary to extend the understanding gained at the eutrophic sites to the more common nutrient-poor regions of Amazonia if we are to understand the Amazon's contribution to global warming. Given that both eutrophic and oligotrophic sites under study are largely in the eastern Amazon, this provides a unique opportunity to examine the possible role of changes in rainfall regime on the vegetation, on species diversity (with potential high mortality of endemics with narrow ranges of adaptability to drier conditions), and on land cover.