International NGOs and Land Use Change in a Southern Highland Region of Ecuador

Nongovernmental organizations are increasingly influencing resource management and land use in areas of small farm agriculture in Latin America. A field study of NGOs working in upper Canar, a region in the southern highlands of Ecuador, documents the changing human environment relations in an indigenous area and the influence of NGOs in the change process. Case studies of PLAN International and CARE indicate that the NGOs are helping marginalized producers shift land use away from traditional grains and tubers toward dairying and vegetables. Given current needs and resource constraints, the new land uses represent effective adaptive strategies. However, the NGO work is having notable consequences for land use intensity and labor utilization patterns.     

Domestic Water Use in Rural Semiarid Africa: A Case Study of Katarko Village in Northeastern Nigeria

Katarko village in the Sahel region of northeastern Nigeria relies entirely on natural sources of water such as rainfall and ground water. Thelatter is potentially the only constant source of water. This study is based on primary data collected in Katarko during a period of 8 months in 1996. Analysis indicates that per capita daily water consumption is higher (44.9 l) in the rainy season than in the dry season (26.1 l). The proportion of households who useless than 150 l per day, the minimum daily requirement recommended by the World Health Organization (Dieterich & Henderson, 1963) increases from 29% during the rainy season to 67% during the dry season. Most households prefer to use water of poor quality that is to be found closer to their homes to traveling long distances to or spending extra time at the water sources to obtain good quality water. Poor water quality, appalling sanitation, and unhygienic water-handling practices, particularly during the dry season, contribute to the high incidence of diarrhea in the village.     

Indigenous Land Use in the Ecuadorian Amazon: A Cross-cultural and Multilevel Analysis

Among the remaining tropical forests of lowland Latin America, many are inhabited by indigenous peoples, and the sustainability of their land uses is a point of heated debate in the conservation community. Numerous small-scale studies have documented changes in indigenous land use in individual communities in the context of expanding frontier settlements and markets, but few studies have included larger populations or multiple ethnic groups. In this paper we use data from a regional-scale survey of five indigenous populations in the Northern Ecuadorian Amazon to describe their agricultural land use practices and investigate the factors that affect those practices. We find the areas cultivated by indigenous households to be small compared to those of nearby mestizo colonists, but a large proportion of indigenous cultivated area is in commercial land uses. We also construct multilevel statistical models to investigate the household and community-level factors that affect indigenous land use. The results reveal significant influences on cultivated area from contextual factors such as access to markets, oil company activities, and the land tenure regime, as well as from household characteristics such as demographic composition, participation in alternative livelihood activities, and human, social and physical capitals. Overall the results are most consistent with market integration as an underlying driver of land use change in indigenous territories of the study area.

Beyond Population and Environment: Household Demographic Life Cycles and Land Use Allocation Among Small Farms in the Amazon

Most research featuring demographic factors in environmental change has focused on processes operating at the level of national or global populations. This paper focuses on household-level demographic life cycles among colonists in the Amazon, and evaluates the impacts on land use allocation. The analysis goes beyond prior research by including a broader suite of demographic variables, and by simultaneously assessing their impacts on multiple land uses with different economic and ecological implications. We estimate a system of structural equations that accounts for endogeneity among land uses, and the findings indicate stronger demographic effects than previous work. These findings bear implications for modeling land use, and the place of demography in environmental research.

Population genetic structure of two water strider species in the Ecuadorian Amazon

1. We used mtDNA sequence variation to estimate population genetic structure between and among water strider populations of Potamobates williamsi and P . sumaco in the Ecuadorian Amazon.
2. Sequencing of the COI mitochondrial gene revealed 16 haplotypes, which were summarised into four haplotype groups. P . williamsi and P . sumaco shared two common and widespread haplotypes.
3. Population structure was moderate and gene flow was low. Both air and river distances were significantly correlated with gene flow and, thus, indicative of isolation by distance.
4. The genetic structure within and among populations of P. williamsi and P. sumaco was probably not influenced by the dynamic tropical lotic system.     

Population and Land Use Effects on Malaria Prevalence in the Southern Brazilian Amazon

Malaria prevalence has been one of the most dramatic outcomes of the occupation of the Brazilian Amazon as exemplified by Northern Mato Grosso, one of the areas of highest malaria prevalence in the Americas in the early 1990s. This paper associates the dynamicsof high malaria prevalence in Northern Mato Grosso with three land uses—small-scalegold mining (garimpos), agricultural colonization/cattle ranching (rural), and urban activities—and their related population characteristics, which constitute riskprofiles. Furthermore, spatial proximity and population mobility between (a) garimpos and new rural settlements and (b) older rural settlements or urban areas are key factors explaining malaria diffusion throughout the region. The paper identifies and characterizes populations at high malaria risk and the effects of land use types on malaria diffusion, providing policymakers with information for regional and local policies to control malaria and minimize its effects on Amazonian populations.     

Land use change in the Amazon estuary: Patterns of caboclo settlement and landscape management

Landsat TM scenes for 1985 and 1991 are used to produce a georeferenced map of land cover and land use for an area of the Amazon estuary inhabited by three populations of caboclos with distinct patterns of land use. This information is combined in a geographic information system with ethnographic and survey research carried out over the past 5 years to develop representative spectral signatures which permit measurement and differentiation of land uses and the detection of change even between small areas of managed floodplain forest and unmanaged forest, and between three distinct age/growth classes of secondary succession following deforestation. Implementation of these procedures permit the scaling up or down of research at different resolutions. Three distinct patterns of land use are examined with differential impact on the environment. Mechanized agriculture at one site has eliminated virtually all the mature upland forest and is now dominated by secondary successional vegetation. The more traditional system of diversified land use at the next site shows a subtle cycling of flooded forest to managed palm forest through time in response to the price of palm fruit and cycling in the use of fallow land. A third site, based on palm fruit extractivism, shows minimal changes in land cover due to persistent specialization on management of flooded forest extraction. There is little evidence that the community with the greatest impact on forest cover is any better off economically than the two communities which have minimal impact on the landscape. This study suggests how a balance between use and conservation in Amazonia may be achieved in floodplain and estuarine areas, and the effectiveness of monitoring these types of land cover from satellite platforms.     

Population Growth and Land Use Intensification in a Subsistence-based Indigenous Community in the Amazon

Shifting cultivation practiced by indigenous peoples living at low population densities in tropical forests has often been described as sustainable and compatible with conservation. However, shifting cultivation at increasing population densities has historically been, and still is, a main cause of deforestation worldwide. As many indigenous peoples in tropical forests currently experience rapid demographic growth, this raises the question to what extent their agricultural activities actually contribute to deforestation. This paper examines land use change in an indigenous community in the Ecuadorian Amazon which is only loosely connected to the market economy, and where agriculture is almost exclusively subsistence oriented. During the last seven decades, people have increasingly begun to clear fallows instead of old-growth forest to farm. Although the population was growing at an estimated 1.6% per year, the expansion of the area of land used for agriculture was only 0.4% per year, corresponding to an annual deforestation rate of only 0.015%. Whereas these changes may seem negligible in terms of deforestation, they do cause hardships to the local people, because of increasing walking distance to old-growth forest, and problems with weeds, pests, and decreasing soil productivity when farming after reclearing fallows.     

2.5D Morphogenesis: modeling landuse and landcover dynamics in the Ecuadorian Amazon

The Ecuadorian Amazon, lying in the headwaters of the Napo and Aguarico River valleys, is experiencing rapid change in Land Use and Land Cover (LULC) conditions and regional landscape diversity uniquely tied to the spontaneous agricultural colonization of the Oriente region of northeastern Ecuador beginning in the mid to late 1970s. Spontaneous colonization occurred on squattered lands located adjacent to oil company roads and in government development sectors composed of multiple 50 ha land parcels organized into `piano key' shaped family farms or fincas. Portions of these fincas were deforested for agricultural extensification depending upon the age of the finca and several site and situation factors. Because fincas are managed at the household level as spatially discrete, temporally independent units, land conversion at the finca-level is recognized as the chief proximate cause of deforestation within the region.Focusing on the spatial and temporal dynamics of deforestation, agricultural extensification, and plant succession at the finca-level, and urbanization at the community-level, a cell-based morphogenetic model of Land Use and Land Cover Change (LULCC) was developed as the foundation for a predictive model of regional LULCC dynamics and landscape diversity. Here, LULC characteristics are determined using a time-series of remotely sensed data (i.e., Landsat Thematic Mapper (TM) and Multispectral Scanner (MSS)) using an experimental [semi-traditional] (hybrid unsupervised-supervised) classification scheme resulting in a time-series data set including LULC images for 1973, 1986, 1989, 1996, and 1999. Pixel histories of LULC type across the time-series were integrated into LULC trajectories and converted into seed or input data sets for LULC modeling to alternate time periods and for model validation. LULC simulations, achieved through cellular automata (CA) methodologies, were run on an annual basis to the year 2010 using 1973 as the initial conditions and the satellite time-series as the `check points' in the simulations. The model was developed using the Imagine Spatial Modeler of the ERDAS image processing software, and enhanced using the Spatial Modeler Language (SML). The model works by (a) simulating the present by extrapolating from the past using the image time-series, (b) validating the simulations via the remotely sensed time-series of past conditions and through field observations of current conditions, (c) allowing the model to iterate to the year 2010, and (d) comparing model outputs to an autoregressive time-series approach for annual conditions that are compared via paired t-tests of pattern metrics run at the landscape-level to define compositional and structural differences between successive model outputs.     

Patterns and Structures of Land Use Change in the Three Rivers Headwaters Region of China

Located in Qinghai Province of China, the Three Rivers Headwaters Region is the source region of the Yangtze, Yellow and Lantsang Rivers, and plays an important role in biodiversity conservation and regulating water supply. Despite many efforts on land use change in Qinghai, knowledge of the spatial variation of land use change is still lacking. This study examines the patterns of land use change across various watersheds, prefectures and the temple surroundings. Remote sensing images of 1987, 1997 and 2007 were analyzed to derive land use distributions; patterns and structures of the landscape were then quantified with landscape metrics. The results illustrated that the Yangtze River headwater region had more diverse and more evenly distributed landscape, while the Lantsang and the Yellow headwater regions showed a decline in landscape diversity. Comparison of the land use patterns of four prefectures revealed that Yushu Prefecture experienced an increase in landscape diversity from 1987 to 2007 while the land use patches in Guoluo Prefecture exhibited more aggregated patterns than other prefectures. Analysis of the spatial variations of land use change in the temple surroundings illustrated that 19.7% and 35.9% of the temples in Guoluo and Yushu Prefectures, respectively, encountered land use change for their immediate areas within 2 km. Comparison of the surroundings of temples and human settlements found that land use change was not evenly distributed, and that greater land use change had occurred for the surroundings of human settlements. Such findings provided insights into the spatial variation of land use change in the Three Rivers Headwaters Region.     

Foraging Behavior and Activity Patterns of Alouatta caraya in the Northeastern Argentinean Flooded Forest

Howling monkeys (Alouatta spp.) are colonizer species, showing a plasticity in behavior that allows them to inhabit different sorts of forests. There is a series of hypotheses relating demography to behavioral and ecological characteristics of howlers: (1) as howler density increases, home range size will decrease; (2) howler groups occupying small home ranges will have a high proportion of leaves in their diet; and, (3) the proportion of mature leaves in the diet is negatively correlated with group daily travel distance. To test hypotheses about howler diet and ranging pattern in relation to food resources, we studied the foraging ecology and general activity patterns of 2 groups of black howlers (Alouatta caraya) inhabiting in flooded forest of Paraná River (Argentina), the habitat with the highest density recorded for Alouatta. We found, in addition to the highest densities, also the smallest home ranges for Alouatta (Group I: 1.7 ha and Group II: 2.2 ha). However, diet was not dominated by leaves, and high quality items—flowers, fruits, new leaves—were a high proportion of the diet all year. Also, daily travel distance is not correlated with the proportion of mature leaves in the diet, but is positively correlated with the number of group confrontations. Finally, we propose a model integrating and interpreting our results as a function of the spatial and temporal distribution of high quality food resources in the Argentinean flooded forest.     

Land Reform and Land-Use Changes in the Lower Amazon: Implications for Agricultural Intensification

Land tenure has been considered one of the key factors that define patterns and change in land-use systems. This paper examines the implications of land reform for household decisions regarding patterns of land use, agricultural intensification, and forest conservation. We look at an Amazonian caboclo settlement in the Lower Amazon that had experienced land reform by the end of the 1980s. Results show that defined land tenure is not enough to guarantee agricultural intensification and forest conservation. In fact, several factors working at different scales are affecting land-use change in the region. At the settlement level, privatization of upland forest has led to an overall increase in cultivated land—pasture and annual crops—and increasing deforestation rates. However, at the farm-property level, different systems of agricultural production—intensive, extensive, or abandonment of land—occur according to availability of labor, and capital, and access to different natural resources.     

青藏高原芨芨草型温性草原不同土地利用方式的理论碳增汇潜力比较

于2009年7~8月对青藏高原芨芨草(Achnatherumsplendens)型温性草原主要分布区的4种土地利用类型──原生草地、退化草地、农田耕种和退耕还草区的土壤容重、土壤有机碳含量和植物地上、地下生物量进行对比研究,以探讨土地利用方式对青藏高原草地生态系统碳储垂向分布的影响.结果表明,土地利用方式显著影响着浅层(0~20 cm)土壤容重和地下生物量(P<0.05);农田耕种和退耕还草对土壤有机碳含量的影响程度可深达60cm;农田耕种区和退耕还草区的地上生物量极显著高于原生草地区和退化草地区(P<0.01);原生草地、退化草地、农田耕种区和退耕还草区的系统(植物+0~40 cm土壤)碳储分别为122.84、108.82、130.68和108.99 t?hm-2;以原生草地区地下系统碳储为参照,退化草地、农田耕种区和退耕还草区的增汇潜力分别为14.05、-6.38和14.88 t?hm-2,但增汇的时间效益和经济效益区别较大.     

Temporal Heterogeneity in the Study of African Land Use

This paper introduces a set of four collaborative papers exploring temporal heterogeneity in the analysis of African land use over a decadal time period, from 10 to 50 years, in the second half of the twentieth century. The four cases were chosen amongst the seven teams of anthropologists, human geographers and remote sensing specialists who had carried out long-term research and who met to discuss their findings at a workshop in 2003. All seven teams’ work and the collective discussion—on Casamance (Senegal), Brong Ahafo (Ghana), Southern Niger/Northern Cote d’Ivoire, Oyo State (Nigeria), Maasai Mara (Kenya and Tanzania), Gwembe (Zambia), and Malawi—inform this introduction. We identify several temporal processes in all the cases, each operating on its own temporal frame: population growth and, above all, mobility; livelihood change through crop and occupational change; tenure ambiguity; powerful though “punctuated” interventions by state policy; and climate change. Conceptual and methodological implications are disussed.

Soil Diversity and Land Use in the United States

Soils are dynamic components of terrestrial ecosystems that historically have been viewed as economic resources by government and private interests. The large-scale conversion of many sections of the United States to agriculture and urban land uses, combined with the growing awareness of the role of soils in global biogeochemistry and ecology, ultimately requires an assessment of the remaining distribution of undisturbed soils in the country. Here we conduct the first quantitative analysis of disturbed and undisturbed soil distribution in the USA using a GIS-based approach. We find that a sizable fraction (4.5%) of the nation's soils are in danger of substantial loss, or complete extinction, due to agriculture and urbanization. In the agricultural belt of the country, up to 80% of the soils that were naturally of low abundance are now severely impacted (greater than 50% conversion to agricultural/urban uses). Undisturbed soils provide ecosystem services that warrant their preservation, including a somewhat complex relationship with rare or endangered plants. The known and unknown attributes of undisturbed soils suggests the need for an integrated biogeodiversity perspective in landscape preservation efforts.     

Home Range and Movement Patterns of White-lipped Peccary (Tayassu pecari) Herds in the Northern Brazilian Amazon1

Two white-lipped peccary (Tayassu pecari) herds were radio-tracked for 5 and 13 mo, respectively, on Maracá Island Ecological Reserve, Roraima, Brazil. Home range size was 109.6 km² for the larger herd (130 animals) and 21.8 km² for the smaller herd (53 animals). Neither herd migrated or moved nomadically during the study period. The herd with the longer observation period increased its home range size during the flooded season by including new sites not used in the nonflooded season and continuing to use the nonflooded season sites. This pattern of simultancously using distinct seasonal ranges also occurred between the rainy and dry periods and the herd regularly and predictably returned to favored feeding sites. Population declines and disappearances in this study and others may have been caused by in situ mortality rather than by long-distance movements.     

Feeding and Refuge Use by Small Fish in the Presence of Cyanobacteria Blooms

We studied the effect of cyanobacteria on foraging and refuge use in small fish. We measured pike larval feeding in the presence of cyanobacteria by counting leftover prey. Our results showed that feeding by pike larvae on zooplankton prey decreased significantly in the presence of non-toxic cyanobacteria. The behaviour can be due to lowered vision caused by turbidity or clogging of the gills. Further, we tested whether the three-spined stickleback use toxic cyanobacteria as a refuge against predators in a choice experiment. The choice experiment was performed in a Y-maze fluviarum, where the fish could select between two different environments. Our results support the refuge use hypothesis because the three-spined stickleback clearly preferred toxic cyanobacteria to the chemical predator signal. To conclude, cyanobacteria decrease feeding rates in fish larvae, but may function as important refuge for e.g. sticklebacks, during predation pressure in pelagic algal blooms.     

Implications of Fire Policy on Native Land Use in the Yukon Flats, Alaska

Through a process of participatory mapping, this research assessed the impacts of the 1984 change in Alaska fire policy from one of exclusion to one of management on Native land use in the Yukon Flats National Wildlife Refuge. Findings suggest that while the change in policy has had little measurable effect on community land use the continued suppression of fire on Native owned lands is having a direct impact on the current availability of wildlife resources to the point of necessitating territorial expansion among Native resource users. However, given the complexity of human nature, the impacts associated with the 1984 policy change should not be reduced to a simplistic cause-and-effect relationship. Rather this analysis demonstrates the interaction as well as the contradiction that occur between policy, culture, and ecology as these factors together have come to influence Native land use.