Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
194,053
result(s) for
"Population ecology"
Sort by:
Countdown : our last, best hope for a future on earth?
\"A powerful investigation into the chances for humanity's future from the author of the bestseller The World Without Us. In his bestselling book The World Without Us, Alan Weisman considered how the Earth could heal and even refill empty niches if relieved of humanity's constant pressures. Behind that groundbreaking thought experiment was his hope that we would be inspired to find a way to add humans back to this vision of a restored, healthy planet-only in harmony, not mortal combat, with the rest of nature. But with a million more of us every 4¿ days on a planet that's not getting any bigger, and with our exhaust overheating the atmosphere and altering the chemistry of the oceans, prospects for a sustainable human future seem ever more in doubt. For this long awaited follow-up book, Weisman traveled to more than 20 countries to ask what experts agreed were the probably the most important questions on Earth-and also the hardest: How many humans can the planet hold without capsizing? How robust must the Earth's ecosystem be to assure our continued existence? Can we know which other species are essential to our survival? And, how might we actually arrive at a stable, optimum population, and design an economy to allow genuine prosperity without endless growth? Weisman visits an extraordinary range of the world's cultures, religions, nationalities, tribes, and political systems to learn what in their beliefs, histories, liturgies, or current circumstances might suggest that sometimes it's in their own best interest to limit their growth. The result is a landmark work of reporting: devastating, urgent, and, ultimately, deeply hopeful. By vividly detailing the burgeoning effects of our cumulative presence, Countdown reveals what may be the fastest, most acceptable, practical, and affordable way of returning our planet and our presence on it to balance. Weisman again shows that he is one of the most provocative journalists at work today, with a book whose message is so compelling that it will change how we see our lives and our destiny\"-- Provided by publisher.
Book
Source Partitioning Using Stable Isotopes: Coping with Too Much Variation
Stable isotope analysis is increasingly being utilised across broad areas of ecology and biology. Key to much of this work is the use of mixing models to estimate the proportion of sources contributing to a mixture such as in diet estimation.
By accurately reflecting natural variation and uncertainty to generate robust probability estimates of source proportions, the application of Bayesian methods to stable isotope mixing models promises to enable researchers to address an array of new questions, and approach current questions with greater insight and honesty.
We outline a framework that builds on recently published Bayesian isotopic mixing models and present a new open source R package, SIAR. The formulation in R will allow for continued and rapid development of this core model into an all-encompassing single analysis suite for stable isotope research.
Journal Article
Ours to share : coexisting in a crowded world
\"Part of the nonfiction Footprints series for middle readers, illustrated with color photographs. Examines how overpopulation leads to unequal sharing of the earth's social and natural resources.\"-- Provided by publisher.
Book
A Meta-Analysis of Local Adaptation in Plants
Local adaptation is of fundamental importance in evolutionary, population, conservation, and global-change biology. The generality of local adaptation in plants and whether and how it is influenced by specific species, population and habitat characteristics have, however, not been quantitatively reviewed. Therefore, we examined published data on the outcomes of reciprocal transplant experiments using two approaches. We conducted a meta-analysis to compare the performance of local and foreign plants at all transplant sites. In addition, we analysed frequencies of pairs of plant origin to examine whether local plants perform better than foreign plants at both compared transplant sites. In both approaches, we also examined the effects of population size, and of the habitat and species characteristics that are predicted to affect local adaptation. We show that, overall, local plants performed significantly better than foreign plants at their site of origin: this was found to be the case in 71.0% of the studied sites. However, local plants performed better than foreign plants at both sites of a pair-wise comparison (strict definition of local adaption) only in 45.3% of the 1032 compared population pairs. Furthermore, we found local adaptation much more common for large plant populations (>1000 flowering individuals) than for small populations (<1000 flowering individuals) for which local adaptation was very rare. The degree of local adaptation was independent of plant life history, spatial or temporal habitat heterogeneity, and geographic scale. Our results suggest that local adaptation is less common in plant populations than generally assumed. Moreover, our findings reinforce the fundamental importance of population size for evolutionary theory. The clear role of population size for the ability to evolve local adaptation raises considerable doubt on the ability of small plant populations to cope with changing environments.
Journal Article
Bridgehead effect in the worldwide invasion of the biocontrol Harlequin Ladybird
Recent studies of the routes of worldwide introductions of alien organisms suggest that many widespread invasions could have stemmed not from the native range, but from a particularly successful invasive population, which serves as the source of colonists for remote new territories. We call here this phenomenon the invasive bridgehead effect. Evaluating the likelihood of such a scenario is heuristically challenging. We solved this problem by using approximate Bayesian computation methods to quantitatively compare complex invasion scenarios based on the analysis of population genetics (microsatellite variation) and historical (first observation dates) data. We applied this approach to the Harlequin ladybird Harmonia axyridis (HA), a coccinellid native to Asia that was repeatedly introduced as a biocontrol agent without becoming established for decades. We show that the recent burst of worldwide invasions of HA followed a bridgehead scenario, in which an invasive population in eastern North America acted as the source of the colonists that invaded the European, South American and African continents, with some admixture with a biocontrol strain in Europe. This demonstration of a mechanism of invasion via a bridgehead has important implications both for invasion theory (i. e., a single evolutionary shift in the bridgehead population versus multiple changes in case of introduced populations becoming invasive independently) and for ongoing efforts to manage invasions by alien organisms (i. e., heightened vigilance against invasive bridgeheads)
Journal Article
Human footprint : everything you will eat, use, wear, buy, and throw out in your lifetime
\"What is your human footprint? Well, it's 13,056 pints of milk; 28,433 showers; 12,888 oranges; 14,518 candy bars; 43,371 cans of soda; and $52,972 worth of clothes, all in one lifetime. And that's just a fraction of the mountain of stuff you'll consume. Think of that times six billion other footprints. Makes you want to step more lightly on the Earth\"--P. [4] of cover.
Book
Marine Reserves Enhance the Recovery of Corals on Caribbean Reefs
The fisheries and biodiversity benefits of marine reserves are widely recognised but there is mounting interest in exploiting the importance of herbivorous fishes as a tool to help ecosystems recover from climate change impacts. This approach might be particularly suitable for coral reefs, which are acutely threatened by climate change, yet the trophic cascades generated by reserves are strong enough that they might theoretically enhance the rate of coral recovery after disturbance. However, evidence for reserves facilitating coral recovery has been lacking. Here we investigate whether reductions in macroalgal cover, caused by recovery of herbivorous parrotfishes within a reserve, have resulted in a faster rate of coral recovery than in areas subject to fishing. Surveys of ten sites inside and outside a Bahamian marine reserve over a 2.5-year period demonstrated that increases in coral cover, including adjustments for the initial size-distribution of corals, were significantly higher at reserve sites than those in non-reserve sites. Furthermore, macroalgal cover was significantly negatively correlated with the change in total coral cover over time. Recovery rates of individual species were generally consistent with small-scale manipulations on coral-macroalgal interactions, but also revealed differences that demonstrate the difficulties of translating experiments across spatial scales. Size-frequency data indicated that species which were particularly affected by high abundances of macroalgae outside the reserve had a population bottleneck restricting the supply of smaller corals to larger size classes. Importantly, because coral cover increased from a heavily degraded state, and recovery from such states has not previously been described, similar or better outcomes should be expected for many reefs in the region. Reducing herbivore exploitation as part of an ecosystem-based management strategy for coral reefs appears to be justified.
Journal Article
Demography and evolutionary ecology of Hadza hunter-gatherers
\"The Hadza, an ethnic group indigenous to northern Tanzania, are one of the few remaining hunter-gatherer populations in existence. With a history spanning 130,000 years but rapidly losing their land and traditional ways of life, this book offers a unique opportunity to capture the lifestyle of a declining population. Blurton Jones interweaves data from ecology, demography and evolutionary ecology to present a comprehensive analysis of the Hadza foragers. Discussion centres on expansion of the adaptationist perspective beyond topics customarily studied in human behavioural ecology, to interpret a wider range of anthropological concepts. Analysing behavioural aspects, with a specific focus on relationships and their wider impact on the population, this book reports the demographic consequences of different patterns of marriage and the availability of helpers such as husbands, children, and grandmothers. Essential for researchers and graduate students alike, this book will challenge preconceptions of human sociobiology\"-- Provided by publisher.
Book
Spatial Pattern Enhances Ecosystem Functioning in an African Savanna
The finding that regular spatial patterns can emerge in nature from local interactions between organisms has prompted a search for the ecological importance of these patterns. Theoretical models have predicted that patterning may have positive emergent effects on fundamental ecosystem functions, such as productivity. We provide empirical support for this prediction. In dryland ecosystems, termite mounds are often hotspots of plant growth (primary productivity). Using detailed observations and manipulative experiments in an African savanna, we show that these mounds are also local hotspots of animal abundance (secondary and tertiary productivity): insect abundance and biomass decreased with distance from the nearest termite mound, as did the abundance, biomass, and reproductive output of insect-eating predators. Null-model analyses indicated that at the landscape scale, the evenly spaced distribution of termite mounds produced dramatically greater abundance, biomass, and reproductive output of consumers across trophic levels than would be obtained in landscapes with randomly distributed mounds. These emergent properties of spatial pattern arose because the average distance from an arbitrarily chosen point to the nearest feature in a landscape is minimized in landscapes where the features are hyper-dispersed (i.e., uniformly spaced). This suggests that the linkage between patterning and ecosystem functioning will be common to systems spanning the range of human management intensities. The centrality of spatial pattern to system-wide biomass accumulation underscores the need to conserve pattern-generating organisms and mechanisms, and to incorporate landscape patterning in efforts to restore degraded habitats and maximize the delivery of ecosystem services.
Journal Article