Women and development: A highland New Guinea example

This paper presents an analysis of household variables and their relationship to success in cash cropping among the Gainj of Madang Province, Papua New Guinea. Censuses and household surveys from 1978, the year in which cash cropping began, and 1983 provide data that show different patterns of change in household structure for more and less commercially successful households. The results illustrate the importance of women's labor in economic development and the dynamic nature of the relationship between household structure and economic development.     

Examining the social landscapes of alternative reproductive strategies

Social environments are inherently dynamic, often changing depending on the frequency and outcomes of conspecific interactions – they can be simultaneously the targets and agents of selection. Understanding how organisms settle in heterogeneous social environments and the effects this has on reproductive success is vital to our understanding of the selective forces at work in wild populations. From an intensive behavioural and ecological study of territoriality in the polymorphic white‐throated sparrow (Zonotrichia albicollis), we demonstrate that males of the two morphs inhabit social niches that correspond to their respective alternative reproductive strategies. By integrating molecular ecology and Geographic Information Systems, we generated continuous, socio‐spatial models of local conspecific density and cuckoldry risk. Our results suggest that the morphs segregate their territories based on socio‐spatial variables, creating a heterogeneous social landscape that matches each behavioural phenotype with a favourable social environment. Specifically, the monogamous tan males tended to settle in low‐density areas that were also low for cuckoldry risk, while the opposite was true for the promiscuous white males. This pattern of socio‐spatial heterogeneity, combined with the social niche partitioning we observed, might act as a social niche polymorphism, and play an important role in maintenance of the alternative reproductive strategies of the white‐throated sparrow. Socio‐spatial factors, similar to those observed in the white‐throated sparrow, may play important roles in the evolution of mating systems in other species, even those with more continuous or cryptic variation.     

Conservationists,hunters and farmers: the European rabbit Oryctolagus cuniculus management conflict in the Iberian Peninsula

相似文献   

Multiple successional pathways in human‐modified tropical landscapes: new insights from forest succession,forest fragmentation and landscape ecology research

Old‐growth tropical forests are being extensively deforested and fragmented worldwide. Yet forest recovery through succession has led to an expansion of secondary forests in human‐modified tropical landscapes (HMTLs). Secondary forests thus emerge as a potential repository for tropical biodiversity, and also as a source of essential ecosystem functions and services in HMTLs. Such critical roles are controversial, however, as they depend on successional, landscape and socio‐economic dynamics, which can vary widely within and across landscapes and regions. Understanding the main drivers of successional pathways of disturbed tropical forests is critically needed for improving management, conservation, and restoration strategies. Here, we combine emerging knowledge from tropical forest succession, forest fragmentation and landscape ecology research to identify the main driving forces shaping successional pathways at different spatial scales. We also explore causal connections between land‐use dynamics and the level of predictability of successional pathways, and examine potential implications of such connections to determine the importance of secondary forests for biodiversity conservation in HMTLs. We show that secondary succession (SS) in tropical landscapes is a multifactorial phenomenon affected by a myriad of forces operating at multiple spatio‐temporal scales. SS is relatively fast and more predictable in recently modified landscapes and where well‐preserved biodiversity‐rich native forests are still present in the landscape. Yet the increasing variation in landscape spatial configuration and matrix heterogeneity in landscapes with intermediate levels of disturbance increases the uncertainty of successional pathways. In landscapes that have suffered extensive and intensive human disturbances, however, succession can be slow or arrested, with impoverished assemblages and reduced potential to deliver ecosystem functions and services. We conclude that: (i) succession must be examined using more comprehensive explanatory models, providing information about the forces affecting not only the presence but also the persistence of species and ecological groups, particularly of those taxa expected to be extirpated from HMTLs; (ii) SS research should integrate new aspects from forest fragmentation and landscape ecology research to address accurately the potential of secondary forests to serve as biodiversity repositories; and (iii) secondary forest stands, as a dynamic component of HMTLs, must be incorporated as key elements of conservation planning; i.e. secondary forest stands must be actively managed (e.g. using assisted forest restoration) according to conservation goals at broad spatial scales.     

Use of indigenous ecological knowledge of the Maasai pastoralists for assessing rangeland biodiversity in Tanzania

This paper incorporates the indigenous ecological knowledge (IEK) of the Maasai pastoralists and ecological methods to assess effects of grazing and cropping on rangeland biodiversity at macro‐ and micro‐landscape scales in northern Tanzania. The joint surveys with pastoralists identified indicator plant species and their associations with micro‐landscapes and livestock grazing suitability (i.e. for cattle and small ruminant grazing), while traditional calf‐pasture reserves (alalili pl. alalilia) were evaluated for preservation of rangeland biodiversity. The macro‐landscapes comprising the cool high plateau (osupuko pl. isipuki) and montane forest highland (endim) were included in the survey. At micro‐landscape scales, the osupuko was classified into uplands (orkung'u), slopes (andamata) and dry valley bottomlands (ayarata). The micro‐landscapes were assessed in terms of herbaceous plant species and woody species richness and risks of soil erosion. Biodiversity varied at both the macro‐ and micro‐landscape scales and in accordance with the land‐use types. Greater plant species diversity and less erosion risks were found in the pastoral landscapes than in the agro‐pastoral landscapes. The calf‐grazing pastures had greater herbaceous species richness than the non‐calf pastures, which in turn had more woody species. The study concludes that the indigenous systems of landscape classification provides a valuable basis for assessing rangeland biodiversity, which ecologists should incorporate into ecological surveys of the rangelands in East Africa in the future.     

禁牧政策下宁夏盐池县农户适应策略及其影响因素

禁牧政策下农户的适应策略是农户为了应对外界干预而做出的各种适应性改变,生计变化是其中最重要的部分。通过实地调查获得研究数据,对比分析禁牧初期和禁牧10a农户生计模式、养殖及种植方面的变化,并以农户的生计资本作为自变量,运用有序多分类和二项的Logistic回归模型分析农户适应策略(农户生计多样性、养殖规模及养殖方式)变化的影响因素。研究得出:1与禁牧初期相比,当前农户的适应策略主要表现为农户生计模式具有初步非农化倾向,生计多样性增加,大部分农户养殖规模减小或不变,农户生产结构有所调整,粮食作物种植面积增加,而经济作物种植面积减小,单只羊的养殖成本增加。2农户生计资本水平对其适应策略具有重要影响,农户生计多样性变化的主要影响因素有人力资本、金融资本和社会资本;影响农户养殖规模变化的主要有自然资本、物质资本、金融资本和社会资本,而影响农户养殖模式选择的主要是物质资本和金融资本因素。     

Introduction history overrides social factors in explaining genetic structure of females in Mediterranean mouflon

Fine‐scale spatial genetic structure of populations results from social and spatial behaviors of individuals such as sex‐biased dispersal and philopatry. However, the demographic history of a given population can override such socio‐spatial factors in shaping genetic variability when bottlenecks or founder events occurred in the population. Here, we investigated whether socio‐spatial organization determines the fine‐scale genetic structure for both sexes in a Mediterranean mouflon (Ovis gmelini musimon × Ovis sp.) population in southern France 60 years after its introduction. Based on multilocus genotypes at 16 loci of microsatellite DNA (n = 230 individuals), we identified three genetic groups for females and two for males, and concurrently defined the same number of socio‐spatial units using both GPS‐collared individuals (n = 121) and visual resightings of marked individuals (n = 378). The socio‐spatial and genetic structures did not match, indicating that the former was not the main driver of the latter for both sexes. Beyond this structural mismatch, we found significant, yet low, genetic differentiation among female socio‐spatial groups, and no genetic differentiation in males, with this suggesting female philopatry and male‐biased gene flow, respectively. Despite spatial disconnection, females from the north of the study area were genetically closer to females from the south, as indicated by the spatial analysis of the genetic variability, and this pattern was in accordance with the common genetic origin of their founders. To conclude, more than 14 generations later, genetic signatures of first introduction are not only still detectable among females, but they also represent the main factor shaping their present‐time genetic structure.     

Farm Households and Land Use in a Core Conservation Zone of the Maya Biosphere Reserve,Guatemala

This paper employs cross-tabular analysis, and multivariate and logistic regression to explore demographic, political-economic, socioeconomic, and ecological patterns of farm households and land use outcomes in an emergent agricultural frontier: the Sierra de Lacandón National Park (SLNP)-a core conservation zone of the Maya Biosphere Reserve (MBR), Petén, Guatemala. Data were obtained from a 1998 probability sample of 241 farm households, the first large detailed household land use survey in Guatemala’s Selva Maya-the largest lowland tropical forest in Central America. Virtually all settler households were poor maize farmers who colonized the SLNP in search of land for subsistence. While they faced similar ecological and economic conditions, land use strategies and patterns of forest clearing varied with demographic, household, and farm characteristics. Findings support and refute elements from previous frontier land use theory and offer policy implications for conservation and development initiatives in the Maya Forest specifically, and in tropical agricultural frontiers in general.

Life history influences how fire affects genetic diversity in two lizard species

‘Fire mosaics’ are often maintained in landscapes to promote successional diversity in vegetation with little understanding of how this will affect ecological processes in animal populations such as dispersal, social organization and re‐establishment. To investigate these processes, we conducted a replicated, spatiotemporal landscape genetics study of two Australian woodland lizard species [Amphibolurus norrisi (Agamidae) and Ctenotus atlas (Scincidae)]. Agamids have a more complex social and territory structure than skinks, so fire might have a greater impact on their population structure and thus genetic diversity. Genetic diversity increased with time since fire in C. atlas and decreased with time since fire in A. norrisi. For C. atlas, this might reflect its increasing population size after fire, but we could not detect increased gene flow that would reduce the loss of genetic diversity through genetic drift. Using landscape resistance analyses, we found no evidence that postfire habitat succession or topography affected gene flow in either species and we were unable to distinguish between survival and immigration as modes of postfire re‐establishment. In A. norrisi, we detected female‐biased dispersal, likely reflecting its territorial social structure and polygynous mating system. The increased genetic diversity in A. norrisi in recently burnt habitat might reflect a temporary disruption of its territoriality and increased male dispersal, a hypothesis that was supported with a simulation experiment. Our results suggest that the effects of disturbance on genetic diversity will be stronger for species with territorial social organization.     

A garden experiment revisited: inter‐generational change in environmental perception and management of the Maya Lowlands,Guatemala

This study reports ethnographic and experimental analyses of inter‐generational changes in native Itza' Maya and immigrant Ladino populations of Guatemala's Petén rainforest concerning understanding of ecological relationships between plants, animals, and humans, and the perceived role of forest spirits in sustaining these relationships. We find dramatic changes in understanding ecological relationships and the perceived role of forest spirits. Itza' Maya conceptions of forest spirits (arux) are now more often confounded with Ladino spirits (duendes), with Itza' spirits no longer reliably serving as forest guardians. These changes correlate with a shift in personal values regarding the forest, away from concern with ecologically central trees and towards monetary incentives. More generally, we describe how economic, demographic, and social changes relate to the loss of a system of beliefs and behaviours that once promoted sustainable agro‐forestry practices. These changes coincide with open access to common pool resources.     

Ecological and socio‐economic impacts of invasive water hyacinth (Eichhornia crassipes): a review

1. Water hyacinth (Eichhornia crassipes) is one of the world’s most invasive aquatic plants and is known to cause significant ecological and socio‐economic effects. 2. Water hyacinth can alter water clarity and decrease phytoplankton production, dissolved oxygen, nitrogen, phosphorous, heavy metals and concentrations of other contaminants. 3. The effects of water hyacinth on ecological communities appear to be largely nonlinear. Abundance and diversity of aquatic invertebrates generally increase in response to increased habitat heterogeneity and structural complexity provided by water hyacinth but decrease due to decreased phytoplankton (food) availability. 4. Effects of water hyacinth on fish are largely dependent on original community composition and food‐web structure. A more diverse and abundant epiphytic invertebrate community may increase fish abundance and diversity, but a decrease in phytoplankton may decrease dissolved oxygen concentrations and planktivorous fish abundance, subsequently affecting higher trophic levels. 5. Little is known about the effects of water hyacinth on waterbird communities; however, increases in macroinvertebrate and fish abundance and diversity suggest a potentially positive interaction with waterbirds when water hyacinth is at moderate density. 6. The socio‐economic effects of water hyacinth are dependent on the extent of the invasion, the uses of the impacted waterbody, control methods and the response to control efforts. Ecosystem‐level research programmes that simultaneously monitor the effects of water hyacinth on multiple trophic‐levels are needed to further our understanding of invasive species.     

Habitat characteristics and species interference influence space use and nest‐site occupancy: implications for social variation in two sister species

Nest‐site selection is an important component of species socio‐ecology, being a crucial factor in establishment of group living. Consequently, nest‐site characteristics together with space‐use proxies may reveal the social organization of species, which is critical when direct observation of social interactions is hindered in nature. Importantly, nest‐site choice is expected to be under strong selective pressures and the object of intra‐ and interspecific competition. Although the bulk of research on sociality focuses on its ecological drivers, our study introduces interspecific competition as a potential factor that could influence social evolution. We investigated the influence of habitat and interspecific competition on the social organization of two sister species of the African four striped mouse, Rhabdomys dilectus dilectus and Rhabdomys bechuanae, in a similar macroenvironment. These species diverged in allopatry and occupy distinct environmental niches. We radiotracked 140 adults to identify their nest‐sites, determine nest characteristics and record groups that shared nest‐sites. Group cohesion was estimated from nest‐site fidelity, group association strength, and home range overlap within versus between group members. We compared the two species in sympatry versus parapatry to determine the impact of species interference on sociality. In parapatry, the two species selected distinct nest‐site types, interpreted as different anti‐predator strategies: R. bechuanae selected fewer, spaced, less concealed nest‐sites whereas R. d. dilectus selected clumped and less visible nest‐sites. Rhabdomys bechuanae also showed more cohesive and stable social groups than R. d. dilectus. In sympatry, compared to R. bechuanae, R. d. dilectus occupied similar nest‐sites, however slightly more exposed and clumped, and displayed similar nest‐site fidelity and group association strength. We conclude that although habitat selection may be an important driver of social divergence in Rhabdomys, species interference, by limiting R. d. dilectus movements and forcing nest‐site sharing may induce new ecological pressures that could influence its social evolution.     

More on the determinants of the fertility transition

Abstract

The economic approach to fertility is an application of the economics theory of consumer behavior. It is assumed that consumers of children are utility‐maximizers with stable preferences over time. Thus, changes in fertility are related to changes in household income and the “price” of children. One concern in this approach is that demographic changes are a product of changes in tastes rather than exogenous changes in economic factors such as the earning ability of women. In this paper, the effect of economic variables on the demand for children in the United States in 1950, 1960, 1970, and 1980 is examined. Support is provided for the hypothesis that the earning ability of women is an important determinant of fertility.     

Key biocultural values to guide restoration action and planning in New Zealand

A pluralist and cross‐cultural approach that accommodates differing values while encouraging the collaboration and social cohesion necessary for the complex task of ecological restoration is needed. We used qualitative and quantitative analyses to investigate value assigned to biocultural restoration of coastal forests in northern New Zealand by 26 interviewees from three groups (environmental managers, Māori community members, and community project leaders). Māori community members primarily emphasized the importance of Cultural Stewardship and Use in the restoration process, while placing less emphasis on Ecological Integrity. Otherwise, all participants shared common trends, culminating in three interrelated value sets: (1) Personal Engagement, (2) Connection, and (3) the generation and transfer of Knowledge & Wisdom. These values demonstrate that restoration's benefits to people and community are as significant as its reparations of ecological components. Despite differences, all stakeholders were united in a broadly common goal to restore socio‐ecological systems. Their knowledge and shared passion for conservation signal enormous promise for accelerated and effective restoration of coastal forests, if it is conducted using a pluralistic approach. Because some values expressed were intangible and complex, with cross‐cultural dimensions, current valuation tools used by ecological economists to guide management investment fail to adequately account for, in particular, Māori values of ecological restoration.     

IUCD acceptors in Trivandrum,Kerala, South India

Abstract

Previous tests of the economic theory of fertility using multivariate regression techniques have generally analyzed only cross‐sectional data. Some students of fertility, notably Janowitz (1973a,b), have argued that such studies must also be conducted with change data. This paper presents tests of the economic theory of fertility with both cross‐sectional and change data for the 48 contiguous states. The cross‐sectional analyses examined the effects of male and female income on the marital fertility of 20–24 year olds for 1950, 1960, and 1970 while controlling for the effects of education, urbanization, race, religion, and population density. Controlling for the effects of the same noneconomic variables, a second set of multivariate regression analyses examined the effects of changes in male and female income on changes in the level of marital fertility of 20–24 year olds during the 1950–60 and 1960–70 periods. Both the analyses with cross‐sectional data and change scores provided support for the economic theory.     

Influence of landscape change on nearshore fisheries in southern Chile

At least half of the world's population resides in the coastal zone and the livelihoods of billions of people are affected either directly or indirectly by the production and sustainability of nearshore fisheries. Landscape change, specifically development of tree plantations, is accelerating worldwide as developing countries integrate into global markets to sell goods, offer climate‐mitigation services (carbon), and/or provide renewable energy. These changes can release excess nutrients into adjacent coastal waters causing eutrophication that alters the structure and function of coastal ecosystems. This study examined the relationship between coastal drainage basin land use/land cover change (LCLUC), specifically development of tree plantations, patterns of chlorophyll‐a in nearshore coastal waters, and the biological condition of commercially important shellfish, Concholepas concholepas (loco) in southern Chile. Locos (N = 1374) were sampled across 13 watersheds (35 853 km²) and 42 fisheries management areas (spanning 250 km of coastline). Locos harvested from management areas influenced by tree plantations had approximately 30% more endobiont (shell‐boring) phoronids, almost twice as many endobiont polychaetes and twice as many epibiont (shell‐attaching) barnacles than locos from areas in close proximity to watersheds dominated by native forests (15–20% of the watershed). Phoronid infested locos from coastal waters adjacent to watersheds with tree plantations were of relatively poor biological condition (smaller and narrower in width) and of reduced market value. Our study suggests that tree plantations result in indirect ecological impacts to coastal fisheries (more nutrients and higher phytoplankton biomass, resulting in smaller, low quality locos), and costs are born by coastal fishers (lower prices for locos). Increases in tree plantations could thus potentially significantly impact coastal fisheries worldwide and such problems should be managed as an interconnected network of land use change, oceanic ecosystems, and economic systems that are considered an integrated socio‐ecological system.     

The Social Life of Rights: ‘Gender Antagonism’, Modernity and Raet in Vanuatu

In the northern Vanuatu town of Luganville a small group of men have responded to social and legal changes engendered by women's rights activists by forming a male support group called ‘Violence Against Men’. Members of this ‘backlash’ movement argue that the insidious promotion of Western‐style ‘women's rights’ is leading to discrimination against men in divorce proceedings, child custody battles, and in domestic violence and rape cases. They directly oppose recent and ongoing legal changes aimed at protecting women from domestic violence, such as Domestic Violence Protection Court Orders, and the repeatedly tabled (but long‐delayed) ‘Family Protection Bill’. Such interventions, they argue, undermine Vanuatu's ‘natural’kastom and Christian patriarchal gender order and, in doing so, pose a serious threat to the socio‐economic productivity of the nation‐state. For other men, however, rather than opposing women's rights activism, such challenges have raised questions about how men might successfully negotiate their identities in ways that are sensitive to contemporary issues of gender equality without undermining existing paradigms. Thus, this paper addresses the value accorded to universalism and relativism in gender activism in Vanuatu, and especially in terms of the linked discourses of kastom, church and modernity. It therefore explores gender relations in terms of the contemporary entanglement of indigenous and exogenous epistemologies, and in doing so argues that the contextual analysis of ‘rights’ should consider the specific historical, political and socio‐cultural circumstances in which they are put to use.     

Social systems and life‐history characteristics of mongooses

The diversity of extant carnivores provides valuable opportunities for comparative research to illuminate general patterns of mammalian social evolution. Recent field studies on mongooses (Herpestidae), in particular, have generated detailed behavioural and demographic data allowing tests of assumptions and predictions of theories of social evolution. The first studies of the social systems of their closest relatives, the Malagasy Eupleridae, also have been initiated. The literature on mongooses was last reviewed over 25 years ago. In this review, we summarise the current state of knowledge on the social organisation, mating systems and social structure (especially competition and cooperation) of the two mongoose families. Our second aim is to evaluate the contributions of these studies to a better understanding of mammalian social evolution in general. Based on published reports or anecdotal information, we can classify 16 of the 34 species of Herpestidae as solitary and nine as group‐living; there are insufficient data available for the remainder. There is a strong phylogenetic signal of sociality with permanent complex groups being limited to the genera Crossarchus, Helogale, Liberiictis, Mungos, and Suricata. Our review also indicates that studies of solitary and social mongooses have been conducted within different theoretical frameworks: whereas solitary species and transitions to gregariousness have been mainly investigated in relation to ecological determinants, the study of social patterns of highly social mongooses has instead been based on reproductive skew theory. In some group‐living species, group size and composition were found to determine reproductive competition and cooperative breeding through group augmentation. Infanticide risk and inbreeding avoidance connect social organisation and social structure with reproductive tactics and life histories, but their specific impact on mongoose sociality is still difficult to evaluate. However, the level of reproductive skew in social mongooses is not only determined by the costs and benefits of suppressing each other's breeding attempts, but also influenced by resource abundance. Thus, dispersal, as a consequence of eviction, is also linked to the costs of co‐breeding in the context of food competition. By linking these facts, we show that the socio‐ecological model and reproductive skew theory share some determinants of social patterns. We also conclude that due to their long bio‐geographical isolation and divergent selection pressures, future studies of the social systems of the Eupleridae will be of great value for the elucidation of general patterns in carnivore social evolution.     

Elucidating biological opportunities and constraints on assisted colonization

Assisted colonization is a proposed climate change adaptation strategy. Martin‐Alc?n et al. (Applied Vegetation Science, this issue) report an experiment to evaluate the efficacy of assisted colonization and identify thermal distance as a critical consideration. By extension, we should consider the role that ecological distance and socio‐political distance play within any plan to reduce extinction risk through assisted colonization.     

Accounting for multiple ecosystem services in a simulation of land‐use decisions: Does it reduce tropical deforestation?

Conversion of tropical forests is among the primary causes of global environmental change. The loss of their important environmental services has prompted calls to integrate ecosystem services (ES) in addition to socio‐economic objectives in decision‐making. To test the effect of accounting for both ES and socio‐economic objectives in land‐use decisions, we develop a new dynamic approach to model deforestation scenarios for tropical mountain forests. We integrate multi‐objective optimization of land allocation with an innovative approach to consider uncertainty spaces for each objective. These uncertainty spaces account for potential variability among decision‐makers, who may have different expectations about the future. When optimizing only socio‐economic objectives, the model continues the past trend in deforestation (1975–2015) in the projected land‐use allocation (2015–2070). Based on indicators for biomass production, carbon storage, climate and water regulation, and soil quality, we show that considering multiple ES in addition to the socio‐economic objectives has heterogeneous effects on land‐use allocation. It saves some natural forest if the natural forest share is below 38%, and can stop deforestation once the natural forest share drops below 10%. For landscapes with high shares of forest (38%–80% in our study), accounting for multiple ES under high uncertainty of their indicators may, however, accelerate deforestation. For such multifunctional landscapes, two main effects prevail: (a) accelerated expansion of diversified non‐natural areas to elevate the levels of the indicators and (b) increased landscape diversification to maintain multiple ES, reducing the proportion of natural forest. Only when accounting for vascular plant species richness as an explicit objective in the optimization, deforestation was consistently reduced. Aiming for multifunctional landscapes may therefore conflict with the aim of reducing deforestation, which we can quantify here for the first time. Our findings are relevant for identifying types of landscapes where this conflict may arise and to better align respective policies.