Level-dependent deforestation trajectories in the Brazilian Amazon from 1970 to 2001

This article demonstrates the importance of examining level-dependent deforestation trajectories that may be undetected within regional analyses. We examine Amazon-wide, sub-regional, settlement, and farm-level deforestation trajectories in the Brazilian Amazon and suggest factors that underlie level-dependent differences in spatial patterns and temporal magnitudes of deforestation from 1970 to 2001. At a sub-regional level, we find significant variation in frequency, magnitude, and intensity of deforestation associated with context-specific processes, including areas that have stopped deforesting, are rapidly reforesting, while at the same time increasing economic value of forest-based production. We use remote-sensing data from 1970 to 2001. For Amazon-wide and state-level analyses, we use data available from Brazil??s National Institute for Space Research. For sub-regional, settlement, and farm-lot levels, time-series Landsat images and aerial photographs and detailed field-based research are used to reconstruct the history of deforestation. Our analysis empirically demonstrates that understanding deforestation trajectories requires differentiating underlying causes at different levels of analysis and to be wary of overarching explanations and solutions that ignore differences in scale.     

Proximate Population Factors and Deforestation in Tropical Agricultural Frontiers

Forest conversion for agriculture expansion is the most salient signature of human occupation of the earth's land surface. Although population growth and deforestation are significantly associated at the global and regional scales, evidence for population links to deforestation at micro-scales—where people are actually clearing forests—is scant. Much of the planet's forest elimination is proceeding along tropical agricultural frontiers. This article examines the evolution of thought on population–environment theories relevant to deforestation in tropical agricultural frontiers. Four primary ways by which population dynamics interact with frontier forest conversion are examined: population density, fertility, and household demographic composition, and in-migration.     

Property Size and Land Cover Change in the Brazilian Amazon

This paper considers the size of a farmer’s property as a key variable influencing land cover and land cover change in rural areas of developing countries. Data from 126 rural familial properties in the region around the city of Santarém, Pará, in the Brazilian Amazon, indicate that property size is important for understanding the trajectories of land cover change. Past research has focused on the distinction between small family farms and large capitalized farms, arguing that family farmers have a higher deforestation intensity, or on estimating the strength of the effect of property size relative to economic or demographic factors. This paper shows that larger familial properties are able both to retain a larger area in forest and to have long enough cycles of use and fallow to allow previously used land to become forested again. Based on these analyses and discussion, we argue that land use and land cover research must consider property size as an organizing principle in order to better comprehend the reciprocal relationship between population and environment in frontier areas of the Brazilian Amazon and other rural landscapes.     

The population,agriculture, and environment nexus in Latin America: country-level evidence from the latter half of the twentieth century

Unprecedented population growth and migration accompanied equally unprecedented land use and land cover change in Latin America during the latter decades of the twentieth century. Country-level data are examined with bivariate statistics to determine relationships between changes in population patterns and land use (agriculture and forest cover) from 1961 to 2001. In South America, large forest areas were eliminated during the period, while exceptionally high rates of forest clearing were ubiquitous in the Central America/Caribbean region. These environmental changes accompanied dissimilar initial population densities and different effects of population change on agriculture. While interacting with a host of political, socio-economic, and geographic processes, it appears that both Malthusian and Boserupian demographic processes were important drivers of deforestation. Given continued, though slowing, population growth, increased urban consumption, and future land use constraints, policy makers face myriad challenges in advancing sustainable agriculture-population dynamics in Latin America.     

Population growth,changing agricultural practices,and environmental degradation in Zaire

This paper examines linkages between the demographic changes taking place in Zaire, particularly overall population growth and rapid urbanization, changes in agricultural practices, and related environmental degradation. Pressures to feed Zaire's rapidly increasing urban population, which fall on a rural population that has been growing relatively slowly in recent years, as well as population growth and increased population density in certain areas of the country, have resulted in changes in agricultural practices that are described in the paper. These changes in turn are leading to declining soil fertility, deforestation, and degradation of the natural resource base. Given present technology and the state of Zaire's economy, the changes in agricultural practices that have emerged in response to population growth, increased population density, and growth in demand for food production do not appear to be sustainable in the long run.     

论人口与环境关系研究的主要思想流派与观点

人口与环境关系的研究和论争已经持续了200多年,近年来这个问题进一步引起国外学术界的重视。但是由于这个领域研究的多方面复杂性,因此在人口与环境关系研究中,存在各种思想流派之间巨大分歧。在大量阅读国外相关文献的基础上,对国外人口与环境研究的主要流派渊源、基本理论等进行简单的回顾和评述,从而为有关方面提供一个关于国际社会对人口与环境领域研究的基本线索。     

Challenging Neo‐Malthusian Deforestation Analyses in West Africa's Dynamic Forest Landscapes

Many influential analyses of West Africa take it for granted that ‘original’ forest cover has progressively been converted and savannized during the twentieth century by growing populations. By testing these assumptions against historical evidence, exemplified for Ghana and Ivory Coast, this article shows that these neo‐Malthusian deforestation narratives badly misrepresent people–forest relationships. They obscure important nonlinear dynamics, as well as widespread anthropogenic forest expansion and landscape enrichment. These processes are better captured, in broad terms, by a neo‐Boserupian perspective on population–forest dynamics. However, comprehending variations in locale‐specific trajectories of change requires fuller appreciation of social differences in environmental and resource values, of how diverse institutions shape resource access and control, and of ecological variability and path dependency in how landscapes respond to use. The second half of the article présents and illustrates such a “landscape structuretion” perspective through case studies from the forest–savanna transition zones of Ghana and Guinea.     

Population and Upland Crop Production in Nang Rong,Thailand

This paper estimates village-level models of the effects of population variables on the area devoted to upland crop production in Nang Rong district, Thailand. The expansion of upland crops is part of the growth of market agriculture in Nang Rong, and a correlate of deforestation in this setting, The results show that population density (measured as density of village settlement) negatively affects area in upland crops while population growth has a positive effect. Changes in land use associated with population change appear to radiate outward from nuclear village centers. As cash economies are established in rural settings, household formation requires a source of income as well as a subsistence stake. Growth in the population of households is a stronger predictor of the area in upland crops than growth in the number of persons.     

Family planning and deforestation: evidence from the Ecuadorian Amazon

Despite an abundant literature exploring the relationship between population growth and forest cover change, comparatively little research has examined the forest cover impacts of family planning use—a key determinant of population growth rates in many developing countries. Using data from a panel survey of farms in the Northern Ecuadorian Amazon, this paper explores whether family planning use affects changes in forest cover. After controlling for household life cycle effects, family planning use among female heads of farm households did not have an independent effect on deforestation, reforestation, or net forest loss between 1990 and 2008. Rather, shorter-term drivers of forest change tend to be associated with household life cycles and shifts in production and consumption. However, family planning will continue to improve development and health outcomes for women by reducing unwanted fertility and may offer longer-term environmental benefits.     

Population Dynamics and Tropical Deforestation: State of the Debate and Conceptual Challenges

What is the role of population in driving deforestation? This question was put forth as a discussion topic in the cyberseminar hosted by Population Environment Research Network (PERN) in Spring, 2003. Contributors from diverse backgrounds weighed in on the discussion, citing key factors in the population-deforestation nexus and suggesting further courses of action and research. Participants explored themes of their own choosing, with many coming to the forefront. Scale, time, and place-based effects were cited as areas in need of particular attention. Consumption patterns as the mechanism for spurring deforestation were discussed, drawing attention to the differential patterns associated with urban vs. rural demands on forest resources and land. The applicability of the IPAT formula and the influence of its component parts, affluence and technology, when operating in tandem with population, was debated. The relation of demographic factors to these pathways was critically examined. Institutional and governmental influence, such as infrastructure and policies affecting access and incentives, the valuation of resources, and institutional failures such as mismanagement and corruption emerged as a crucial set of factors. This article synthesizes the critical debates in the population-deforestation literature, makes suggestions for future paths of research, and discussed possible policy and direct action initiatives.     

Women, non-governmental organizations, and deforestation: a cross-national study

There have been several cross-national studies published in the world polity theoretical tradition that find a strong correlation between nations with high levels of environmental nongovernmental organizations (NGOs) and low levels of various forms of environmental degradation. However, these studies neglect the role that women’s NGOs potentially play in this process. We seek to address this gap by conducting a cross-national study of the association between women’s NGOs and deforestation. We examine this relationship because deforestation often translates into increased household labor, loss of income, and impaired health for women and, as a result, women’s non-governmental organizations have become increasingly involved in dealing with these problems often by protecting forests. We use data from a sample of 61 nations for the period of 1990–2005. We find substantial support for world polity theory that both high levels of women’s and environmental NGOs per capita are associated with lower rates of deforestation. We also find that high levels of debt service and structural adjustment are correlated with higher rates of forest loss. We conclude with a discussion of findings, policy implications, and possible future research directions.     

A primary research on the population influence on ecological environment in the mountain area of the South An Hui Province]

The 16 counties in the mountain region of South Anhui Province have a land mass of 29,176 sq. km and a 1983 population of 491,720,000, a majority of whom are farmers. Forests, tea and grains are the villages' major sources of income. 80% of the area is hilly; the climate is temperate and rainfall is adequate. In recent years, a rapid population increase and inattention to proper use of natural resources have eroded the environment. Since 1949 the population of this area increased 70%, putting tremendous pressure on the land and fuel. The demand for housing, factories, transportation and communication to accomodate the population increase constantly decreases the availability of farmland. Arable land decreased by about 3,000,000 sq. acres between 1949 and 1983. Because the average individual acreage is small, production is low, leading to frequent grain shortages. Forests are then destroyed to make farmland, but in the process, the flora and fauna are disturbed while production remains low and uneven. In addition, firewood, the main source of fuel, will not be replenished rapidly enough to meet the needs of the growing population. The quality of this mountain population also influences ecology. Almost 80% of the people are semi-literate, traditional in their attitudes and customs, and unreceptive to new ideas. Family planning has not been successful here, nor is there a deep understanding of the consequences of deforestation. It is necessary, then, to control this area's population growth, improve the population's quality, raise its environmental consciousness, and utilize its resources effectively.     

Population and deforestation in the Brazilian Amazon: a mediating perspective and a mixed-method analysis

As progress is made in understanding the dynamics of land-use and land-cover change (LUCC), arguments that view population pressure as one of the major factors affecting forest destruction continue to be framed. Following the advances in the field of population-environment studies, this paper contends that a full account of the complex web of drivers involved in tropical deforestation needs to go beyond demographics per se. This paper examines the contribution of the ??population factor?? as a cause of deforestation in Machadinho D??Oeste, Rond?nia, Brazilian Amazonia, an area with significant small-scale farming. Conceptually, the paper shows that socioeconomic status and mediating factors (i.e., education, managerial skills, previous rural experience, integration into the local, and regional contexts), and attitudes and behaviors toward the land parcel development mediate migrants?? relationships with the local environment. The analysis combines multiple data sources (i.e., demographic census, household survey, land-cover maps, in-depth interviews) and analytical approaches (i.e., fuzzy sets statistics, remote-sensing/GIS analysis, interpretivist qualitative assessment) to examine the complex interrelationships between LUCC and human population.     

Demarcating forest, containing disease: land and HIV/AIDS in southern Zambia

The ongoing HIV/AIDS pandemic in southern Africa continues to manifest itself in unexpected ways. While the consequences of the disease appear straightforward in some aspects—e.g., medical, labor, cost—in other respects the repercussions, while large, are nonetheless highly nuanced and can be counterintuitive. This paper reports on the intersection of HIV/AIDS, migration, livelihood adaptation, land tenure, and forest conservation, to outline how adaptation to the pandemic has reworked significant aspects of land tenure to result in increased forest conservation in southern Zambia in the near to medium-term. The research uses a combination of ethnography, case studies, household survey and spatial analyses and finds that HIV/AIDS is used in customary legal settings to enhance land access. We also draw links to practical and theoretical implications of the relationship between HIV/AIDS, land tenure, and deforestation in Sub-Saharan Africa.     

人口老龄化与经济发展水平的相关分析

人口老龄化是社会经济发展影响人口发展过程的必然结果 ,本文通过实例分析了人口老龄化与经济发展的关系 ,然后选择指标 ,通过相关分析、回归分析 ,建立人口老龄化与经济发展水平之间关系的数学模型     

Land,Fertility, and the Population Establishment

Attempts to demonstrate the dependence of fertility decline in the Third World on radical change have often depended on simplistic statistical analyses. Here some of the data used to explore the relationship between fertility, and land size and ownership, are re-examined. It is concluded that the land-fertility hypotheses of Stokes and Schutjer are not supported by the evidence, but that such analyses are inherently inconclusive and ambiguous. Instead, an understanding of the wider institutional context is called for. The Population Establishment – foreign and international donors supporting population programmes and research – recruits an intelligentsia to validate its activities. The philosophy of this intelligentsia is examined and rejected through an analysis of ideas it derives from the World Fertility Survey and the Matlab family planning project. It is concluded that the Establishment perpetuates rapid population growth by legitimizing unpopular and elitist governments, and by misleading them to believe that fertility decline can, indeed, occur in a political economy of inequality and injustice.     

北京市优质公共资源配置与人口疏解研究

文章分析了北京市优质公共资源配置与人口分布现状,并提出实现中心城人口疏解的相应对策。指出,人口迁移的一个重要因素是各种优质公共资源的吸引。北京的教育、医疗卫生、文化、体育、公共交通等优质公共资源在中心城高度聚集是导致人口在中心城聚集的一个重要原因。为此,要疏解中心城人口,需采取如下措施:政府主导,在新城高标准配置优质公共资源;优先疏解中心城教育、医疗资源;强化轨道交通的引导作用,降低新城居民出行的成本。     

人口对干旱区生态环境演变的作用机制与问题分析——以新疆为例

本文以中国最大的干旱区———新疆为例 ,分析了干旱区人口变动与生态环境退化之间的主要作用机制以及存在的主要矛盾。认为人口数量增长引起的资源环境压力 ,是导致干旱区环境退化的主要人为诱因 ,而人口的素质状况则决定了人口资源环境压力下最终的环境演化方向与后果。在各种矛盾中 ,人口的快速增长所导致的资源环境压力 ,是目前新疆人口与环境之间最大的矛盾 ,而不均匀的人口空间分布模式则加剧了这种资源环境压力 ,新疆较低的人口综合素质则决定了新疆长期以来在资源环境面前所采取的主要方式和最终环境后果 ,是以环境退化为主的表现模式。