scholarly journals Interconnections accelerate collapse in a socio-ecological metapopulation

2017 ◽  
Author(s):  
Zachary Dockstader ◽  
Chris T. Bauch ◽  
Madhur Anand
Keyword(s):  
Population Growth ◽  
Ecological Systems ◽  
Human Populations ◽  
Metapopulation Model ◽  
Over Exploitation

AbstractResource over-exploitation can have profound effects on both ecosystems and the human populations residing in them. Models of population growth based on a depletable resources have been studied previously, but relatively few consider metapopulation effects. Here we analyze a socio-ecological metapopulation model where resources grow logistically on each patch. Each population harvests resources on its own patch to support population growth, but can also harvest resources from other patches when their own patch resources become scarce. We find that allowing populations to harvest from other patches significantly accelerates collapse and also increases the parameter regime for which collapse occurs, compared to a model where populations are not able to harvest resources from other patches. As the number of patches in the metapopulation increases, collapse is more sudden, more severe, and occurs sooner. These effects also persist under scenarios of asymmetry and inequality between patches. We conclude that metapopulation effects in socio-ecological systems can be both helpful and harmful and therefore require urgent study.

scholarly journals Interconnections Accelerate Collapse in a Socio-Ecological Metapopulation

2019 ◽  
Vol 11 (7) ◽  
pp. 1852 ◽  
Author(s):  
Zachary Dockstader ◽  
Chris Bauch ◽  
Madhur Anand
Keyword(s):  
Theoretical Models ◽  
Ecological Sustainability ◽  
Human Populations ◽  
Metapopulation Model ◽  
Single Population ◽  
Metapopulation Structure ◽  
Model Dynamics ◽  
Simplifying Assumptions ◽  
Over Exploitation ◽  
The Impact

Over-exploitation of natural resources can have profound effects on both ecosystems and their resident human populations. Simple theoretical models of the dynamics of a population of human harvesters and the abundance of a natural resource being harvested have been studied previously, but relatively few models consider the effect of metapopulation structure (i.e., a population distributed across discrete patches). Here we analyze a socio-ecological metapopulation model based on an existing single-population model used to study persistence and collapse in human populations. Resources grow logistically on each patch. Each population harvests resources on its own patch to support population growth, but can also harvest resources from other patches when their own patch resources become scarce. We show that when populations are allowed to harvest resources from other patches, the peak population size is higher, but subsequent population collapse is significantly accelerated and across a broader parameter regime. As the number of patches in the metapopulation increases, collapse is more sudden, more severe, and occurs sooner. These effects persist under scenarios of asymmetry and inequality between patches. Our model makes simplifying assumptions in order to facilitate insight and understanding of model dynamics. However, the robustness of the model prediction suggests that more sophisticated models should be developed to ascertain the impact of metapopulation structure on socio-ecological sustainability.

scholarly journals Ecology of the Anthropocene signals hope for consciously managing the planetary ecosystem

2021 ◽  
Vol 118 (28) ◽  
pp. e2024150118
Author(s):  
Clarence Lehman ◽  
Shelby Loberg ◽  
Michael Wilson ◽  
Eville Gorham
Keyword(s):  
Population Growth ◽  
Cultural Evolution ◽  
Human Population ◽  
Human Populations ◽  
Present Moment ◽  
Minimal Set ◽  
The Past ◽  
Food Species ◽  
Large Predators ◽  
Population Numbers

Human populations have grown to such an extent that our species has become a dominant force on the planet, prompting geologists to begin applying the term Anthropocene to recognize the present moment. Many approaches seek to explain the past and future of human population growth, in the form of narratives and models. Some of the most influential models have parameters that cannot be precisely known but are estimated by expert opinion. Here we apply a unified model of ecology to provide a macroscale summary of the net effects of many microscale processes, using a minimal set of parameters that can be known. Our models match estimates of historic and prehistoric global human population numbers and provide predictions that correspond to some of the more complicated current models. In addition to fitting the data well they reveal that, amidst enormous complexity in our human and prehuman past, three key ecological discontinuities have occurred in turn: 1) becoming dominant competitors of large predators rather than their prey, 2) becoming mutualists with food species rather than acting as predators upon them, and 3) changing from a regime of uncontrolled population growth to one of controlled fertility instead. All three processes have been interlinked with cultural evolution and all three ushered in developments of the Anthropocene. Understanding the trajectories that have delivered us to this stage can help guide prudent paths into the future.

scholarly journals Development and Environment: An Assessment of Population Growth vis-a-vis Soil Erosion in Nepal

2014 ◽  
Vol 7 ◽  
pp. 173-196 ◽  
Author(s):  
Rishikesh Pandey
Keyword(s):  
Soil Erosion ◽  
Population Growth ◽  
Environmental Degradation ◽  
Policy Process ◽  
White Men ◽  
Population Pressure ◽  
Hybrid Knowledge ◽  
Research Findings ◽  
Over Exploitation ◽  
Development And Environment

This paper discusses the environmental myths and narratives prevailing in Nepal in reference to the population growth and soil erosion. Soil erosion is taken as primary element of environmental degradation by the theory of the Himalayan Environmental Degradation (HED). Many myths and narratives were generated by the vested interest groups to develop the HED. Population growth and over exploitation of natural resource were considered as the prominent causes of soil erosion related environmental degradation. The myths and narratives based on the theory of the HED are still influential in development and environmental policy process in Nepal. In this background this paper highlights some of the research findings that are contrary to conventional belief i.e. population growth lead to soil erosion. The paper is based on literature review. The research evidences from both social and natural sciences are entertained. This paper generates alternative thinking to end the hegemony and unquestionable acceptance of the findings of research undertaken by 'Western, White men' as truth; and their recommendations as the 'blue print' solutions. Critics over orthodox environmentalism and neo-Malthusian accounts are made to validate the ‘hybrid knowledge’ generated in this paper. There are evidences that population pressure have promoted soil erosion. However, Himalayan environmental dynamism which is purely a natural process is far more responsible for soil erosion in the Himalaya. Hence, it is suggested that a critical assessment of any ‘facts’ obtained from research should be made before making them the narratives and reflecting them in policy process. DOI: http://dx.doi.org/10.3126/dsaj.v7i0.10442 Dhaulagiri Journal of Sociology and Anthropology Vol. 7, 2013; 173-196

scholarly journals Fertility control to mitigate human–wildlife conflicts: a review

2014 ◽  
Vol 41 (1) ◽  
pp. 1 ◽  
Author(s):  
Giovanna Massei ◽  
Dave Cowan
Keyword(s):  
Population Growth ◽  
Wildlife Management ◽  
Population Level ◽  
Fertility Control ◽  
Public Consultation ◽  
Human Populations ◽  
Wildlife Diseases ◽  
Isolated Populations ◽  
Wild Mammals ◽  
Practical Applications

As human populations grow, conflicts with wildlife increase. Concurrently, concerns about the welfare, safety and environmental impacts of conventional lethal methods of wildlife management restrict the options available for conflict mitigation. In parallel, there is increasing interest in using fertility control to manage wildlife. The present review aimed at analysing trends in research on fertility control for wildlife, illustrating developments in fertility-control technologies and delivery methods of fertility-control agents, summarising the conclusions of empirical and theoretical studies of fertility control applied at the population level and offering criteria to guide decisions regarding the suitability of fertility control to mitigate human–wildlife conflicts. The review highlighted a growing interest in fertility control for wildlife, underpinned by increasing numbers of scientific studies. Most current practical applications of fertility control for wild mammals use injectable single-dose immunocontraceptive vaccines mainly aimed at sterilising females, although many of these vaccines are not yet commercially available. One oral avian contraceptive, nicarbazin, is commercially available in some countries. Potential new methods of remote contraceptive delivery include bacterial ghosts, virus-like particles and genetically modified transmissible and non-transmissible organisms, although none of these have yet progressed to field testing. In parallel, new species-specific delivery systems have been developed. The results of population-level studies of fertility control indicated that this approach may increase survival and affect social and spatial behaviour of treated animals, although the effects are species- and context-specific. The present studies suggested that a substantial initial effort is generally required to reduce population growth if fertility control is the sole wildlife management method. However, several empirical and field studies have demonstrated that fertility control, particularly of isolated populations, can be successfully used to limit population growth and reduce human–wildlife conflicts. In parallel, there is growing recognition of the possible synergy between fertility control and disease vaccination to optimise the maintenance of herd immunity in the management of wildlife diseases. The review provides a decision tree that can be used to determine whether fertility control should be employed to resolve specific human–wildlife conflicts. These criteria encompass public consultation, considerations about animal welfare and feasibility, evaluation of population responses, costs and sustainability.

Twinning and the r/K Reproductive Strategy: A Critique of Rushton's Theory

1992 ◽  
Vol 41 (1) ◽  
pp. 73-83 ◽  
Author(s):  
G. Allen ◽  
A.W. Eriksson ◽  
J. Fellman ◽  
P. Parisi ◽  
S.G. Vandenberg
Keyword(s):  
Environmental Factors ◽  
Population Growth ◽  
Parental Care ◽  
Ethnic Groups ◽  
Ethnic Differences ◽  
Reproductive Strategy ◽  
Reproductive Strategies ◽  
Human Populations ◽  
Efficient Utilization ◽  
Mode Of Reproduction

AbstractThe theory of r selection, favoring population growth, as opposed to K selection, favoring more efficient utilization of resources, has in recent years been applied by Rushton to contrast human ethnic groups in terms of their r/K reproductive strategies, suggesting the existence of a continuum from r groups, producing many offspring but providing little parental care, to K groups, producing few offspring but providing much parental care. Rushton's theory, which is largely based on ethnic differences in twinning rates, is here critically examined. It is pointed out that twinning rate differences are not necessarily genetic in origin since various environmental factors clearly play a role, and also that twinning, as a mode of reproduction, is not necessarily an r strategy, considering the high prenatal and perinatal selection to which it has been, and still is, associated. Moreover, Rushton misinterprets a number of relevant aspects related to the biology of twinning. The claim that ethnic differences in twinning rates provide evidence for an r/K typology in human populations with respect to reproductive strategies does not appear to be warranted.

scholarly journals Human Niche Construction and Population Growth in Pre-Columbian Amazonia

2017 ◽  
Author(s):  
Manuel Arroyo-Kalin
Keyword(s):  
Population Growth ◽  
Late Holocene ◽  
Niche Construction ◽  
Human Populations ◽  
Archaeological Research ◽  
Environmental Alteration ◽  
Human Niche Construction ◽  
Continued Use ◽  
Research Demands ◽  
Landscape Legacies

The use of Niche Construction Theory in archaeological research demands that we establish empirically how human-constructed niches acted as legacies that shaped the selection pressures affecting past human populations. One potential approach is to examine whether human demography changed as a result of the continued use of landscapes enduringly transformed by past societies. This paper presents proxies for Amazonian population growth during the late Holocene and discusses their significance within the broader context of landscape legacies resulting from cumulative anthropic environmental alteration during pre-Columbian times.

scholarly journals Linking economic growth pathways and environmental sustainability by understanding development as alternate social–ecological regimes

2018 ◽  
Vol 115 (38) ◽  
pp. 9533-9538 ◽  
Author(s):  
Graeme S. Cumming ◽  
Stephan von Cramon-Taubadel
Keyword(s):  
Economic Growth ◽  
Population Growth ◽  
Natural Resources ◽  
Equilibrium Point ◽  
Resource Use ◽  
Environmental Sustainability ◽  
Empirical Test ◽  
Equilibrium Points ◽  
National Level ◽  
Human Populations

Scientists understand how global ecological degradation is occurring but not why it seems to be so difficult to reverse. We used national-level data and a mathematical model to provide an empirical test of the hypothesis that national economies display two distinct economic regimes that are maintained by self-reinforcing feedbacks between natural resources and society. Our results not only support previous findings that two distinct groups exist, but also show that countries move toward one of these two different equilibrium points because of their different patterns of natural resource use and responses to population growth. At the less economically developed equilibrium point maintained by “green-loop” feedbacks, human populations depend more directly on ecosystems for income. At the more economically developed equilibrium point maintained by “red-loop” feedbacks, nonecosystem services (e.g., technology, manufacturing, services) generate the majority of national gross domestic product (GDP), but increasing consumption of natural resources means that environmental impacts are higher and are often exported (via cross-scale feedbacks) to other countries. Feedbacks between income and population growth are pushing countries farther from sustainability. Our analysis shows that economic growth alone cannot lead to environmental sustainability and that current trajectories of resource use cannot be sustained without breaking feedback loops in national and international economies.

scholarly journals Contrasting Signatures of Population Growth for Mitochondrial DNA and Y Chromosomes among Human Populations in Africa

2007 ◽  
Vol 25 (3) ◽  
pp. 517-525 ◽  
Author(s):  
Maya Metni Pilkington ◽  
Jason A. Wilder ◽  
Fernando L. Mendez ◽  
Murray P. Cox ◽  
August Woerner ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Population Growth ◽  
Human Populations ◽  
Y Chromosomes

The Third Royal Society Nuffield Lecture Demographic Prediction

1967 ◽  
Vol 168 (1011) ◽  
pp. 119-139 ◽  
Keyword(s):  
Population Growth ◽  
Long Range ◽  
Royal Society ◽  
Main Part ◽  
Historical Context ◽  
Human Populations ◽  
Wide Applicability ◽  
The Third ◽  
The Absolute ◽  
Demographic Prediction

The main part of this paper is concerned with the boldest and most comprehensive form of demographic prediction—the forecasting of total populations. That form may be regarded as subsuming many more limited types of prediction. In practice, the method of approach in forecasting total populations has not infrequently been very different from that followed in attempting to predict the behaviour of the specific components of population growth. But conceptually, at least, the prediction of total populations represents an extension of the efforts made since the beginnings of demography to derive order from the data on mortality and fertility. Such order has often been found. But attempts to use it as a basis for prediction have not been very successful, and the broader the front the less successful has been the product. Nor are there grounds for believing that long-range, overall predictions are likely to be much more reliable in the future. Nevertheless, the attempts have not been uninstructive. And it is of interest to consider them in a wider historical context—that of the endeavours of demographers to generalize and to discover regularities relating to human populations. These endeavours, which have naturally varied widely in their explicitness, may be grouped under two heads. First, attempts which, generalizing from a particular situation, assumed that the generalization would have a wide applicability, whether or not the absolute levels of fertility or mortality were different. Secondly, generalizations which explicitly included time and change in their framework. Examples of both types are found at various stages in the development of demo­graphy. One example is indeed already present in John Graunt’s Natural and Political Observations , the first specifically demographic publication—an attempt to formulate what later came to be referred to as the ̒law of mortality’ (1)*.

scholarly journals Human uniqueness? Life history diversity among small-scale societies and chimpanzees

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0239170
Author(s):  
Raziel J. Davison ◽  
Michael D. Gurven
Keyword(s):  
Life History ◽  
Population Growth ◽  
Child Mortality ◽  
Adult Mortality ◽  
Vital Rate ◽  
Small Scale ◽  
Human Populations ◽  
Infant Survival ◽  
Selection Pressures ◽  
Human Subsistence

Background Humans life histories have been described as “slow”, patterned by slow growth, delayed maturity, and long life span. While it is known that human life history diverged from that of a recent common chimpanzee-human ancestor some ~4–8 mya, it is unclear how selection pressures led to these distinct traits. To provide insight, we compare wild chimpanzees and human subsistence societies in order to identify the age-specific vital rates that best explain fitness variation, selection pressures and species divergence. Methods We employ Life Table Response Experiments to quantify vital rate contributions to population growth rate differences. Although widespread in ecology, these methods have not been applied to human populations or to inform differences between humans and chimpanzees. We also estimate correlations between vital rate elasticities and life history traits to investigate differences in selection pressures and test several predictions based on life history theory. Results Chimpanzees’ earlier maturity and higher adult mortality drive species differences in population growth, whereas infant mortality and fertility variation explain differences between human populations. Human fitness is decoupled from longevity by postreproductive survival, while chimpanzees forfeit higher potential lifetime fertility due to adult mortality attrition. Infant survival is often lower among humans, but lost fitness is recouped via short birth spacing and high peak fertility, thereby reducing selection on infant survival. Lastly, longevity and delayed maturity reduce selection on child survival, but among humans, recruitment selection is unexpectedly highest in longer-lived populations, which are also faster-growing due to high fertility. Conclusion Humans differ from chimpanzees more because of delayed maturity and lower adult mortality than from differences in juvenile mortality or fertility. In both species, high child mortality reflects bet-hedging costs of quality/quantity tradeoffs borne by offspring, with high and variable child mortality likely regulating human population growth over evolutionary history. Positive correlations between survival and fertility among human subsistence populations leads to selection pressures in human subsistence societies that differ from those in modern populations undergoing demographic transition.

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