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1.
Indigenous peoples’ participation in the co-management of protected areas is recognised as essential for conserving both cultural and biological diversity. While this practice is increasingly common, few studies have quantitatively evaluated the efficacy of these initiatives. Here we examine levels of knowledge and involvement among the Agta, a hunter-gatherer population who co-manage the Northern Sierra Madre Natural Park, the largest protected area in the Philippines. We find that the Agta generally possess low levels of knowledge about the protected area they are supposed to co-manage. Participation in park management is hampered by several factors, including a lack of cultural sensitivity regarding the Agta’s foraging lifestyle among park officials and little political will to realistically empower and support the Agta as co-managers. Recommendations to strengthen Agta participation – and indigenous peoples’ participation in protected area management more widely – are made to help protect the world’s remaining cultural and biological diversity.  相似文献   

2.
Most accounts of human life history propose that women have short reproductive spans relative to their adult lifespans, while men not only remain fertile but carry on reproducing until late life. Here we argue that studies have overlooked evidence for variation in male reproductive ageing across human populations. We apply a Bayesian approach to census data from Agta hunter-gatherers and Gambian farmers to show that long post-reproductive lifespans characterise not only women but also males in some traditional human populations. We calculate three indices of reproductive ageing in men (oldest age at reproduction, male late-life reproduction, and post-reproductive representation) and identify a continuum of male reproductive longevity across eight traditional societies ranging from !Kung, Hadza and Agta hunter-gatherers exhibiting low levels of polygyny, early age at last reproduction and long post-reproductive lifespans, to male Gambian agriculturalists and Turkana pastoralists showing higher levels of polygyny, late-life reproduction and shorter post-reproductive lifespans. We conclude that the uniquely human detachment between rates of somatic senescence and reproductive decline, and the existence of post-reproductive lifespans, are features of both male and female life histories, and therefore not exclusive consequences of menopause.  相似文献   

3.
Tropical rainforests are subject to extensive degradation by commercial selective logging. Despite pervasive changes to forest structure, selectively logged forests represent vital refugia for global biodiversity. The ability of these forests to buffer temperature‐sensitive species from climate warming will be an important determinant of their future conservation value, although this topic remains largely unexplored. Thermal buffering potential is broadly determined by: (i) the difference between the “macroclimate” (climate at a local scale, m to ha) and the “microclimate” (climate at a fine‐scale, mm to m, that is distinct from the macroclimate); (ii) thermal stability of microclimates (e.g. variation in daily temperatures); and (iii) the availability of microclimates to organisms. We compared these metrics in undisturbed primary forest and intensively logged forest on Borneo, using thermal images to capture cool microclimates on the surface of the forest floor, and information from dataloggers placed inside deadwood, tree holes and leaf litter. Although major differences in forest structure remained 9–12 years after repeated selective logging, we found that logging activity had very little effect on thermal buffering, in terms of macroclimate and microclimate temperatures, and the overall availability of microclimates. For 1°C warming in the macroclimate, temperature inside deadwood, tree holes and leaf litter warmed slightly more in primary forest than in logged forest, but the effect amounted to <0.1°C difference between forest types. We therefore conclude that selectively logged forests are similar to primary forests in their potential for thermal buffering, and subsequent ability to retain temperature‐sensitive species under climate change. Selectively logged forests can play a crucial role in the long‐term maintenance of global biodiversity.  相似文献   

4.
Our understanding of the effects of tropical cyclones on species composition and dynamics of forest communities is mainly derived from studies that have considered single cyclonic events. Here we examined changes in the tree species and functional trait composition in an 8-ha Dipterocarp forest at Palanan in the northeastern Philippines that is subject to a high frequency of cyclonic disturbance (1–4 cyclones annually). The plot has been censused four times over a 16-year interval allowing us to consider the medium-term forest dynamics in response to repeated cyclones. We hypothesized that as the forest community in Palanan has been selected under frequent disturbance by cyclones, it should show little functional change across the census intervals. We analyzed changes in demography, species composition, and community-weighted functional traits (specific leaf area, leaf area, wood density, and specific growth rate) across the censuses and compared these against cyclone intensities during the census intervals. Demographic changes across census years suggest that the community responded to cyclonic disturbances through substantial turnover in the small- and medium-size individuals, and that there has been an increase in plot-level stem density and basal area across the measured period. Trait compositional changes from 1994 to 2010 were mostly small, but indicate a shift towards species with larger leaves and faster growth rates—traits that are associated with fast recovery after disturbance. These changes all coincide with a large intense cyclone between the second and third censuses, suggesting that cyclone strength, more than cyclone frequency, affects this forest.  相似文献   

5.
Habitat loss and invasive predators increasingly threaten global biodiversity. Here we use a landscape‐scale experimental approach to explore the individual and synergistic effects of logging and an invasive predator, the red fox Vulpes vulpes on two common native arboreal vertebrates (a predator and prey species) in south‐eastern Australia. We used site occupancy methods to evaluate different models evaluating the effects of site specific forest logging disturbance, lethal fox baiting and forest structural elements for explaining variation in site occupancy of a large monitor lizard Varanus varius, and a marsupial prey, the common ringtail possum Pseudocheirus peregrinus across a complex forest landscape. Site occupancy of ringtail possum was influenced by habitat resources and the structural complexity of forest, which indirectly mediated predation risk. Presence of fox baiting had no direct effect on the ringtail site occupancy. In contrast, access to prey resources and fox baiting appeared to best explain site occupancy variation in monitor lizards across the landscape. While these species are affected primarily by separate disturbances, synergistic interactions between the processes may intensify their effects. Our results demonstrate that species susceptibility to disturbance processes are highly idiosyncratic. This approach makes efficient use of integrated modelling to aid conservation management at both local and landscape levels.  相似文献   

6.
This article draws on concepts of power from political ecology and political sociology to describe the ways that the Tla-o-qui-aht First Nation (a Canadian indigenous people) have attempted to realize their goals under the broad rubric of their Tribal Parks initiative. Like some other Indigenous peoples’ and Community Conserved territories and Areas (ICCAs), the Tribal Parks example features de facto legal pluralism, lack of clear tenure and/or legal recognition, oppositional and/or cooperative relationships with other actors, and situations where local actors are influenced by intersecting global discourses on conservation and indigenous rights and culture. Globally, ICCAs are a form of protected area and are potentially critical in terms of meeting ambitious global protected area targets as well in addressing issues related to the rights and well-being of indigenous peoples. As such, understanding the ‘customary law or other effective means’, or the dynamics of power through which indigenous groups are able (or not) to realize their protected area goals is of global significance. This article illuminates the contours of power through two specific Tribal Parks case studies: the first involves contestations over industrial logging, while the second focuses on the establishment and implementation of what came to be called an ‘ecosystem services fee’ paid by ecotourism outfitters operating within a Tribal Park. Results highlight that the Tla-o-qui-aht have drawn power from different sources and exercised it by different means including turning to the Courts in a context of legal uncertainty, protest and direct action coupled with appeals to public opinion, developing and drawing on relationships with both local and non-local interests, and by strategically ‘tapping into’ prominent discourses.  相似文献   

7.
The increased global demand for tropical timber has driven vast expanses of tropical forests to be selectively logged worldwide. While logging impacts on wildlife are predicted to change species distribution and abundance, the underlying physiological responses are poorly understood. Although there is a growing consensus that selective logging impacts on natural populations start with individual stress‐induced sublethal responses, this literature is dominated by investigations conducted with vertebrates from temperate zones. Moreover, the sublethal effects of human‐induced forest disturbance on tropical invertebrates have never been examined. To help address this knowledge gap, we examined the body fat content and relative abundance of three dung beetle species (Coleoptera: Scarabaeinae) with minimum abundance of 40 individuals within each examined treatment level. These were sampled across 34 plots in a before‐after control‐impact design (BACI) in a timber concession area of the Brazilian Amazon. For the first time, we present evidence of logging‐induced physiological stress responses in tropical invertebrates. Selective logging increased the individual levels of fat storage and reduced the relative abundance of two dung beetle species. Given this qualitative similarity, we support the measurement of body fat content as reliable biomarker to assess stress‐induced sublethal effects on dung beetles. Understanding how environmental modification impacts the wildlife has never been more important. Our novel approach provides new insights into the mechanisms through which forest disturbances impose population‐level impacts on tropical invertebrates.  相似文献   

8.
Partnership programs have gained importance in forestry management. In Indonesia, profit sharing and agroforestry are examples of partnership programs between forest managers and local communities. In this paper, we analyze potential conflicts among participants in these programs. First, we derive a recursive formula to determine the future value of a compartment of plantation to the society, which includes both the forest owner and the local community. While trees are young, the land is also used for agriculture, which is an agroforestry program. When there is a high rate of future discounting and a high rate of natural disturbances, the society may find it profitable to continue the agricultural use of the land. Second, we calculate the profit for the forest owner and the local community separately. To prevent illegal logging, the owner shares a fraction of the profit obtained by selling logs with the local people, which is a profit-sharing program. Illegal logging greatly reduces the profit for the forest owner, especially when trees are tall. Illegal logging of old cohorts is harmful to the local people as well. In contrast, illegal logging of young cohorts provides profit to the local people because they will be hired to replant young trees. Our analysis shows an “overlooking period” in which a conflict of interest exists between the forest owner and the local community. We indicate that the overlooking period can be mitigated by coordination of the shared profit and the wage for the workers.  相似文献   

9.
Habitat modification and biological invasions are key drivers of global environmental change. However, the extent and impact of exotic plant invasions in modified tropical landscapes remain poorly understood. We examined whether logging drives exotic plant invasions and whether their combined influences alter understory plant community composition in lowland rain forests in Borneo. We tested the relationship between understory communities and local‐ and landscape‐scale logging intensity, using leaf area index (LAI) and aboveground biomass (AGB) data from 192 plots across a logging‐intensity gradient from primary to repeatedly logged forests. Overall, we found relatively low levels of exotic plant invasions, despite an intensive logging history. Exotic species were more speciose, had greater cover, and more biomass in sites with more local‐scale canopy loss. Surprisingly, though, exotic species invasion was not related to either landscape‐scale canopy loss or road configuration. Moreover, logging and invasion did not seem to be acting synergistically on native plant composition, except that seedlings of the canopy‐dominant Dipterocarpaceae family were less abundant in areas with higher exotic plant biomass. Current low levels of invasion, and limited association with native understory community change, suggest there is a window of opportunity to manage invasive impacts. We caution about potential lag effects and the possibly severe negative impacts of exotic plant invasions on the long‐term quality of tropical forest, particularly where agricultural plantations function as permanent seed sources for recurrent dispersal along logging roads. We therefore urge prioritization of strategic management plans to counter the growing threat of exotic plant invasions in modified tropical landscapes.  相似文献   

10.
South East Asia is widely regarded as a centre of threatened biodiversity owing to extensive logging and forest conversion to agriculture. In particular, forests degraded by repeated rounds of intensive logging are viewed as having little conservation value and are afforded meagre protection from conversion to oil palm. Here, we determine the biological value of such heavily degraded forests by comparing leaf-litter ant communities in unlogged (natural) and twice-logged forests in Sabah, Borneo. We accounted for impacts of logging on habitat heterogeneity by comparing species richness and composition at four nested spatial scales, and examining how species richness was partitioned across the landscape in each habitat. We found that twice-logged forest had fewer species occurrences, lower species richness at small spatial scales and altered species composition compared with natural forests. However, over 80 per cent of species found in unlogged forest were detected within twice-logged forest. Moreover, greater species turnover among sites in twice-logged forest resulted in identical species richness between habitats at the largest spatial scale. While two intensive logging cycles have negative impacts on ant communities, these degraded forests clearly provide important habitat for numerous species and preventing their conversion to oil palm and other crops should be a conservation priority.  相似文献   

11.
A hallmark of human social cognition is the tendency for both adults and children to favour members of their own groups. Critically, this in-group bias exerts a strong influence on cooperative decision-making: people (i) tend to share more with members of their in-group and (ii) differentially enforce fairness norms depending on the group membership of their interaction partners. But why do people show these group biases in cooperation? One possibility is that the enforcement of cooperative norm violations is an evolved mechanism supporting within-group cooperation (Norms-Focused Hypothesis). Alternatively, group bias in cooperation could be a by-product of more general affective preferences for in-group members (Mere Preferences Hypothesis). Here, we appraise evidence from studies of both adults and children with the goal of understanding whether one of these two accounts is better supported by existing data. While the pattern of evidence is complex, much of it is broadly consistent with the Mere Preferences Hypothesis and little is uniquely supportive of the Norms-Focused Hypothesis. We highlight possible reasons for this complexity and suggest ways that future work can continue to help us understand the important relationship between group bias and cooperation.  相似文献   

12.
Being able to identify reliable friends and allies is key to surviving and thriving in the social world. Many cooperative accounts of friendship argue that people select friends based on how helpful and generous they are. While people certainly like helpful and generous others, here we explore a context in which people might respond negatively to a friend being prosocial: When one's friend is more helpful or generous toward another friend. We argue that such preferential prosociality prompts negative reactions, even when the alternative is a friend being less prosocial overall, because giving preferentially to another friend may be viewed as a threat of potential displacement of one's own friendship. In four studies (N?=?702), we predict and find that people respond negatively to a friend who was more helpful (Studies 1–2) and generous (Studies 3–4), preferring instead that a friend be less helpful and generous overall. Importantly, this preferential prosociality was viewed as particularly negative when the recipient was another friend and was seen as much less negative when the recipient was a relative (Study 1 and 4) or a romantic partner (Study 2). We discuss the implications of these results for cooperation and alliance-based accounts of friendship.  相似文献   

13.
In tropical forests, selective logging removes large trees that are often the main contributors to pollination. We studied pollination patterns of the African mahogany, Entandrophragma cylindricum (Sapelli). We investigated two plots in Cameroon corresponding to three tree densities: unlogged forest (Ndama 2002), a mildly logged forest 1 year after logging (Ndama 2003) and a severely logged forest 30 years after logging (Dimako). We used four microsatellite markers to perform paternity analysis. Selfing remained below 2% in all treatments. Pollen flow was mainly long distance but with some proximity effects. Average observed within-plot pollination distances were 338, 266 and 385 m, and pollination by trees outside the plots was 70% (Ndama 2002), 74% (Ndama 2003) and 66% (Dimako). Despite sampling a limited number of seeds from a limited number of mother trees, we obtained seeds sired by 35.6-38.3% of the potential within-plot pollen donors. While trees 20 cm in diameter contributed to pollination, results in Dimako suggest that individual larger trees contribute more to pollination than small ones. This effect was not detected in the other treatments. The results suggest extensive pollen flow in Sapelli. Hence, in Sapelli, the main limiting factor for regeneration after logging may be a reduction in the number of trees capable of producing seeds rather genetic effects due to limits to pollen dispersal.  相似文献   

14.
Population Dynamics of. Philippine Rain Forest People: The San Ildefonso Agta. John D. Early and Thomas N. Headland. Gainesville: University Press of Florida, 1998.208 pp.  相似文献   

15.
Tropical forest disturbance is a key driver of global biodiversity decline. On continents, the effects of logging are greatest on endemic species, presumably because disturbance is more likely to cover narrower distributions (the “cookie cutter” model). Islands hold disproportionate biodiversity, and are subject to accelerating biotic homogenization, where specialist endemics are lost while generalists persist. We tested responses of tropical island mammals to logging at multiple spatial scales, using a long‐term experimental test in a Pacific archipelago. The most widely distributed ecological generalists did not decline after logging, and we detected no overall changes in relative abundance or species diversity. However, endemics with small ranges did decline in response to logging. The least mobile and most range‐restricted species declined even at the smallest spatial scale, supporting the cookie cutter model for sedentary species, and suggesting that habitat change due to selective logging is contributing to biotic homogenization on islands.  相似文献   

16.
The Convention on Biological Diversity aims to encourage and enable countries to conserve biological diversity, to use its components sustainably and to share benefits equitably. Species richness and endemism are two key attributes of biodiversity that reflect the complexity and uniqueness of natural ecosystems. National data on vertebrates and higher plants indicate global concentrations of biodiversity and can assist in defining priorities for action. Projections indicate that species and ecosystems will be at maximum risk from human activities during the next few decades. Prompt action by the world community can minimise the eventual loss of species. Highest priorities should be to: (i) strengthen the management of ecosystems containing a large proportion of global biodiversity; (ii) help developing countries complete their biodiversity strategies and action plans, monitor their own biodiversity, and establish and maintain adequate national systems of conservation areas; (iii) support actions at the global level, providing benefit to all countries in managing their own biodiversity. Generally, resources will best be spent in safeguarding ecosystems and habitats that are viable and important for global biodiversity, and which are threatened by factors that can be controlled cost-effectively. Other important criteria are representativeness, complementarity and insurance.  相似文献   

17.
Ecologists have used Global Positioning Systems (GPS) to track animals for 30 years. Issues today include logging frequency and precision in estimating space use and travel distances, as well as battery life and cost. We developed a low‐cost (~US$125), open‐source GPS datalogger based on Arduino. To test the system, we collected positions at 20‐s intervals for several 1‐week durations from cattle and sheep on rangeland in North Dakota. We tested two questions of broad interest to ecologists who use GPS collars to track animal movements: (1) How closely do collared animals cluster in their herd? (2) How well do different logging patterns estimate patch occupancy and total daily distance traveled? Tested logging patterns included regular logging (one position every 5 or 10 min), and burst logging (positions recorded at 20‐s intervals for 5 or 10 min per hour followed by a sleep period). Collared sheep within the same pasture spent 75% of daytime periods within 51 m of each other (mean = 42 m); collared cattle were within 111 m (mean = 76 m). In our comparison of how well different logging patterns estimate space use versus constant logging, the proportion of positions recorded in 1‐ and 16‐ha patches differed by 2%–3% for burst logging and 1% for regular logging. Although all logging patterns underestimated total daily distance traveled, underestimations were corrected by multiplying estimations by regression coefficients estimated by maximum likelihood. Burst logging can extend battery life by a factor of 7. We conclude that a minimum of two collars programmed with burst logging robustly estimate patch use and spatial distribution of grazing livestock herds. Research questions that require accurately estimating travel of individual animals, however, are probably best addressed with regular logging intervals and will thus have greater battery demands than spatial occupancy questions across all GPS datalogger systems.  相似文献   

18.
Ubel PA  Baron J  Asch DA 《Bioethics》1999,13(1):57-68
Background: Some members of the general public feel that patients who cause their own organ failure through smoking, alcohol use, or drug use should not receive equal priority for scarce transplantable organs. This may reflect a belief that these patients (1) cause their own illness, (2) have poor transplant prognoses or, (3) are simply unworthy. We explore the role that social acceptability, personal responsibility, and prognosis play in people's judgments about transplant allocation.
Methods: By random allocation, we presented 283 prospective jurors in Philadelphia county with one of five questionnaire versions. In all questionnaires, subjects were asked to distribute transplantable hearts between patients with and without a history of three controversial behaviors (eating high fat diets against doctors' advice, cigarette smoking, or intravenous drug use). Across the five questionnaire versions, we varied the relative prognosis of the transplant candidates and whether their behavior caused their primary organ
Results: Subjects were significantly less willing to distribute organs to intravenous drug users than to cigarette smokers or people eating high fat diets (p le; 0.0005), even when intravenous drug users had better transplant outcomes than other patients. Subjects' allocation decisions were influenced by transplant prognosis, but not by whether the behavior in question was causally responsible for the patients' organ failure.
Conclusion: People's unwillingness to give scarce transplantable organs to patients with controversial behaviors cannot be explained totally on the basis of those behaviors either causing their primary organ failure or making them have worse transplant prognoses. Instead, many people believe that such patients are simply less worthy of scarce transplantable organs.  相似文献   

19.
ABSTRACT: BACKGROUND: Young people around the world are increasingly combining alcohol with energy drinks (AEDs). However, as yet, limited research has been conducted examining this issue, particularly in terms of exploring patterns of consumption, social practices and the cultural contexts of AED consumption. We sought to understand how AEDs are used and socially constructed among young people. METHODS: We conducted 25 hours of observation in a variety of pubs, bars and nightclubs, as well as in-depth interviews with ten young people who regularly consumed AEDs during a session of alcohol use. RESULTS: In this pilot study, participants were highly organised in their AED consumption practices and reported rarely altering this routine. Some young people consumed upwards of eight AEDs on a typical night, and others limited their use to between three and five AEDs to avoid unpleasant consequences, such as sleep disturbances, severe hangovers, heart palpitations and agitation. Wakefulness and increased energy were identified as the primary benefits of AEDs, with taste, reduced and increased intoxication, and sociability reported as additional benefits. Young AED users were brand sensitive and responded strongly to Red Bull imagery, as well as discounted AEDs. Finally, some young people reported substituting illicit stimulants with energy drinks. CONCLUSIONS: Combining energy drinks with alcohol is now a normalised phenomenon and an integral and ingrained feature of the night-time economy. Despite this, many young people are unaware of recommended daily limits or related harms. While some young people consume AEDs to feel less drunk (consistent with motivations for combining alcohol with illicit stimulants), others report using AEDs to facilitate intoxication. While preliminary, our findings have relevance for potential policy and regulatory approaches, as well as directions for future research.  相似文献   

20.
Logging and hunting are two key direct threats to the survival of wildlife in the tropics, and also disrupt important ecosystem processes. We investigated the impacts of these two factors on the different stages of the seed dispersal cycle, including abundance of plants and their dispersers and dispersal of seeds and recruitment, in a tropical forest in north-east India. We focused on hornbills, which are important seed dispersers in these forests, and their food tree species. We compared abundances of hornbill food tree species in a site with high logging and hunting pressures (heavily disturbed) with a site that had no logging and relatively low levels of hunting (less disturbed) to understand logging impacts on hornbill food tree abundance. We compared hornbill abundances across these two sites. We, then, compared the scatter-dispersed seed arrival of five large-seeded tree species and the recruitment of four of those species. Abundances of hornbill food trees that are preferentially targeted by logging were two times higher in the less disturbed site as compared to the heavily disturbed site while that of hornbills was 22 times higher. The arrival of scatter-dispersed seeds was seven times higher in the less disturbed site. Abundances of recruits of two tree species were significantly higher in the less disturbed site. For another species, abundances of younger recruits were significantly lower while that of older recruits were higher in the heavily disturbed site. Our findings suggest that logging reduces food plant abundance for an important frugivore-seed disperser group, while hunting diminishes disperser abundances, with an associated reduction in seed arrival and altered recruitment of animal-dispersed tree species in the disturbed site. Based on our results, we present a conceptual model depicting the relationships and pathways between vertebrate-dispersed trees, their dispersers, and the impacts of hunting and logging on these pathways.  相似文献   

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